1. Field of the Invention
The present invention relates to an electrophotographic photoconductor that is used in electrophotographic printers, copiers, fax machines and the like (hereafter also referred to simply as “photoconductor”), to a method for producing the electrophotographic photoconductor, and to an electrophotographic apparatus. More particularly, the present invention relates to an electrophotographic photoconductor that, by containing a polymer of specific structure, exhibits excellent contamination resistance, electrical characteristic stability, and ozone resistance, to a method for producing the electrophotographic photoconductor, and to an electrophotographic apparatus.
2. Background of the Related Art
The electrophotographic photoconductor has a basic structure wherein a photoconductive layer having a photoconductive function is disposed on a conductive support. Ongoing research and development are actively carried out on organic electrophotographic photoconductors that utilize organic compounds as functional components for charge generation and transport, given the advantages that organic electrophotographic photoconductors afford, such as material diversity, high productivity, safety and the like. The use of organic electrophotographic photoconductors in copiers, printers and the like is thus becoming more widespread.
Generally, a photoconductor must fulfill the function of holding surface charge in the dark, generating charge when receiving light, and transporting the charge thus generated. Such photoconductors encompass so-called single layer-type photoconductors that are provided with a single photoconductive layer that combines the above functions, and so-called multilayer-type (of function-separated type) photoconductors provided with a photoconductive layer that is a stack of layers functionally separated into a charge generation layer that fulfils mainly the function of charge generation upon reception light, and a charge transport layer that fulfils the function of transporting the charge that is generated in the charge generation layer upon reception of light.
The above photoconductive layers are generally formed by coating a conductive support with a coating solution in which a charge generation material, a charge transport material and a binder resin are dissolved or dispersed in an organic solvent. In many instances a polycarbonate is used as the binder resin in organic electrophotographic photoconductors, in particular in the outermost surface layer, since polycarbonates are resistant to friction with paper and with blades for toner removal, and boast excellent flexibility and good exposure transparency. Among the foregoing, bisphenol Z polycarbonates are widely used as the binder resin. Technologies in which such polycarbonates are used as a binder resin include, for instance, Japanese Patent Application Publication No. S61-62040 (Patent literature 1).
Electrophotographic printing devices are required to possess ever higher durability and sensitivity, and faster responses, to cope with, for instance, increases in the number of prints to be printed in a networked office, and with the rapid development of lightweight electrophotographic printing machines. These devices, moreover, are held to strict requirements in terms of being little affected by gases, such as ozone and NOx that are generated in the device, and exhibiting little fluctuation in image characteristics arising from variations in the usage environment (room temperature and humidity).
Recent developments in color printers, and the growing prevalence of the latter, have been accompanied with a need for higher printing speeds, smaller equipment and fewer constituent members, as well as the need for accommodating various usage environments. Under such circumstances, there is a pressing demand for photoconductors that exhibit little variation in image characteristics and electrical characteristics caused by repeated use and/or derived from fluctuations in the usage environment (room temperature and environment). Conventional technologies have thus far failed to meet these requirements simultaneously to a sufficient degree.
Ozone is a widely known example of a gas that is generated in equipment. Ozone is generated by a charger or roller charger that triggers corona discharge. The photoconductor becomes thus exposed to residual ozone or dwelling ozone within the equipment. It is found that the organic substances that make up the photoconductor become oxidized thereby, and, as a result, the original structure of the photoconductor breaks down, and the photoconductor characteristics are significantly impaired. Moreover, it is found that ozone oxidizes the nitrogen in air into NOx, which in turn alters the organic substances that make up the photoconductor.
It is deemed that not only does characteristic deterioration elicited by such gases extend to the outermost layer of the photoconductor, but also adverse effects arise when the gas flows into the interior of the photoconductive layer. It is found that the outermost layer itself of the photoconductor is scraped off, though slightly, on account of friction with the above-described various members. When a harmful gas flows into the interior of the photoconductive layer, the organic substances in the photoconductive layer may undergo structural breakdown. Suppressing the inflow of such harmful gas is thus an issue to be addressed. In tandem-type color electrophotographic apparatuses that rely on a plurality of photoconductors, in particular, variation in color tone occurs as a result of differences in the degree of influence of the gas, depending on, for instance, the position at which drums are disposed in the device. Such variations are deemed to constitute an impediment to forming adequate images. Therefore, it is found that characteristic deterioration caused by gas is a particularly important issue in tandem-type color electrophotographic apparatuses.
The photoconductor surface may also be contaminated by ozone, nitrogen oxides and the like that are generated during charging of the photoconductor. Problems that arise in such a case include, for instance, image smearing by those contaminants themselves, as well as lowered surface lubricity caused by the adhered substances, greater likelihood of adhesion of paper dust and toner, and likelier occurrence of blade squealing, curling, surface scratches and the like.
It is also found that human sebum and the like becomes adhered to the photoconductor surface during repair of the electrophotographic apparatus and during the operation of replacing photoconductor units. Thus far, however, the durability of photoconductors against such contaminant adhesion has been not necessarily sufficient, and surface cracks, as well as image defects such as white spots and black spots occur in some instances when human nose fat or scalp sebum is left adhered to the surface of the photoconductor over long periods of time.
Various methods for improving the outermost surface layer of photoconductors have been proposed in order to solve the above problems. Specifically, various polycarbonate resin structures have been proposed in order to enhance the durability of photoconductor surfaces. For instance, Japanese Patent Application Publication No. 2004-354759 (Patent literature 2) and Japanese Patent Application Publication No. H04-179961 (Patent literature 3) propose polycarbonate resins that comprise a specific structure, but not enough consideration is given to compatibility with various charge transport agents and various additives, or to resin solubility. For instance, Japanese Patent Application Publication No. 2004-85644 (Patent literature 4) proposes a polycarbonate resin that comprises a specific structure; however, a resin having a highly bulky structure includes large spaces between polymers, and thus substances released during charging, as well as contact members and foreign matter, permeate readily into the photoconductive layer, and it is accordingly difficult to achieve sufficient durability. Japanese Patent Application Publication No. H03-273256 (Patent literature 5) proposes a polycarbonate having a special structure, in order to enhance printing durability and coatability, but does not sufficiently disclose additives or charge transport materials that are combined with the polycarbonate. Patent literature 5 is problematic in that maintaining stable electrical characteristics over long periods of time is difficult.
Japanese Patent Application Publication No. 2010-276699 (Patent literature 6) proposes the feature of adding a highly branched polymer and a polymerizable charge transport agent to a surface protective layer, to enhance thereby abrasion properties and transfer properties, but coating solution stability is still an issue. Japanese Patent Application Publication No. 2003-255580 (Patent literature 7) proposes the feature of incorporating, into the surface layer of the photoconductor, a binder resin and a linear vinyl polymer having long-chain alkyl groups at side chains. However, it is found that upon polymerization of a vinyl polymer in a solution in the presence of another binder resin, it is difficult to control the molecular weight and the resin skeleton, due to presence of that other resin. Regarding improvements in wear resistance by a surface protective layer, Japanese Patent Application Publication No. 2011-64734 (Patent literature 8) proposes a technology that involves configuring a surface protective layer that contains a cured product having a three-dimensional crosslinked structure and formed out of a predetermined radically polymerizable compound, a trifunctional or higher functional radically polymerizable monomer, and a radically polymerizable compound having a charge transporting structure, but this configuration is problematic in terms of productivity, since the photoconductive layer has a multilayer structure. Improvements derived from the charge transport layer are an important issue herein.
Transfer current tends to increase in color printers on account of toner color overlap and/or the use of transfer belts. When printing on paper of various sizes, a difference in transfer fatigue arises between portions with paper and portions without paper. This in turn exacerbates differences in image density, which is problematic. In case of frequent printing on small-sized paper, bare photoconductor portions over which the paper does not pass (paper non-passage sections) are continuously and directly affected by transfer, and exhibit greater transfer fatigue than bared photoconductor portions over which paper does pass (paper passage sections). As a result, when printing is subsequently performed on large-size paper, the above discrepancy in transfer fatigue between paper passage sections and paper non-passage sections gives rise to a potential difference in the developed area, which translates into observable differences in density. This trend becomes yet more pronounced as transfer current increases. Under such circumstances, the demand has intensified for photoconductors that exhibit little fluctuation in image characteristics and electric characteristics as a result of repeated use, or on account of fluctuations in the usage environment (room temperature and environment), and that exhibit excellent transfer resiliency, particularly in color printer, as compared to monochrome printers. Conventional technologies have thus far failed to meet these requirements simultaneously to a sufficient degree.
Various additives, such as hindered phenol compounds, phosphorus compounds, sulfur compounds, amine compounds, hindered amine compounds and the like have been proposed to enhance gas resistance. The current situation, however, is that these technologies fail to provide sufficient gas resistance, or, even if satisfactory characteristics are exhibited in terms of gas resistance, no satisfactory results are achieved, through a combination of resins and charge transport materials, regarding electrical characteristics, for instance, responsiveness, image memory and potential stability in endurance printing. The applicants had proposed diester compounds in WO 2011/108064 (Patent literature 9) and Japanese Patent Application Publication No. 2007-279446 (Patent literature 10), but have since made further progress in the study of combinations of more appropriate binder resins and high-mobility charge transport materials.
Various conventional technologies have been proposed pertaining to improvement of the surface layer of photoconductors. However, these technologies as disclosed in the citations above were not all sufficient as regards electrical characteristics such as light response, and also contamination resistance towards sebum, photoconductor productivity and the like.
Therefore, it is an object of the present invention to provide an electrophotographic photoconductor that has excellent contamination resistance and stable electrical characteristics and so forth upon repeated use, and superior transfer resistance and gas resistance, and to provide a method for producing the electrophotographic photoconductor, and an electrophotographic apparatus.


1. Field of the Invention
The field of invention relates to pillow construction, and more particularly pertains to a new and improved pillow template apparatus wherein the same is arranged for the severing of a fabric web for pillow construction while simultaneously orienting a pattern relative to the fabric web.
2. Description of the Prior Art
The cutting and removal of a web portion for construction of a pillow results in a non-uniform typical construction of the resultant pillow should the individual severing such a web not accommodate and provide for a convex side wall construction, whereupon stuffing the pillow permits a final resultant product of linear size. While the prior art, such as exemplified in U.S. Pat. Nos. 3,440,980; 4,930,382; 3,774,558; and 5,058,285 provides for various template structure relative to sewing procedures, the instant invention overcomes deficiencies of the prior art by providing for a template structure arranged for the specific severing of a web for the construction of a symmetrically oriented pillow and in this respect, the present invention substantially fulfills this need.


Optical attenuation of interferers in a radio frequency signal has been accomplished by modulating a beam of coherent light with the signal, removing the unwanted interference spectral components from the modulated beam, and then down-converting the beam to provide a radio signal which is free of these interference components.
Such a technique is shown in U.S. Pat. Nos. 4,699,466 and 4,522,466, assigned to the present assignee. The teachings of these patents are meant to be incorporated herein by way of reference.
The aformentioned technique filters the modulated radiation through an optical Fourier transform lens, a spatial filter and an inverse Fourier transform lens.
In particular, U.S. Pat. No. 4,522,466 teaches that the filter attenuation can be maximized by utilizing recursive methods. The coherent light is passed through the optical filtering system a number of times to provide extremely high notching attenuation on the order of 40 dB, or greater.
It would be desirable, however, to increase the notch depth to 80 dB, or more, or possibly notch the signal to the noise floor to remove all EMI.
The invention has as one of its objectives to provide an improved system and method of optically processing radio frequency signals to remove unwanted EMI, wherein a greater notch depth can be achieved than has been heretofore accomplished.
Another object of this invention is to provide a technique and system which reduces the number of filtering elements in a cascaded, multiple channel optical array.


1. Field of the Invention
The present invention relates to a water dissolvable or water dispersible produce label for individually labeling various fruits and vegetables and more specifically, to a dissolvable produce label that contains an organic cleansing produce wash to help clean the individually labeled fruit or vegetable by aiding in the removal of wax, dirt, bacteria, pesticides and fungicides. This invention further relates to a dissolvable produce-cleansing produce label that is water resistant in transit.
2. Background
Current produce labels require removal by the end user. The end user must first peel the produce label off of each fruit individually and dispose of the label(s) before washing and/or eating. These labels are seen as a source of frustration by the end user. They are, for the most part, difficult to peel off and separate from your finger during disposal and add waste to an ever-growing trash problem. Also, current produce labels do nothing in the way of helping the user to clean their fruit. In fact, current fruit labels leave behind an adhesive residue that is very difficult to wash off with water alone.
The end user is warned against using detergent, laundry bleach or soap to clean their produce, as fruits and vegetables are porous and can absorb the soap or bleach. Therefore, produce washes have been formulated to help clean fruits and vegetables better than washing with water alone. There are currently dozens of companies manufacturing and selling “produce wash” as an expensive aftermarket cleansing solution to help consumers clean their fruits and vegetables. Manufacturers currently producing Produce Wash include: Veggie Wash, Eat Cleaner Fruit & Vegetable Wash, Fit Fruit & Vegetable Wash, Ultimate Fruit & Vegetable Wash, Mom's Veggiewash, Earth Friendly Fruit & Vegetable Wash, Enviro-one Fruit Wash, etc. . . . .
Produce labeling provides for fast and accurate checkout. In addition to offering basic product information, the PLU codes printed on produce labels also indicate whether a fruit is conventional, organic or genetically modified. Some labels now include a HarvestMark Number that provides additional information like where it was grown and whether or not the product is subject to a recall. With the HarvestMark number, the end user can also view photos of the farm, or the story behind the farmer, give feedback about the product they purchased, and discover nutrition information, and even recipes. Produce labels also provide branding space to build consumer trust. With branding in mind, fruit growers, distributors and supermarket chains are continually looking for opportunities to responsibly show their commitment to providing their customers with a clean product and a more enjoyable user experience.
It is desirable to have a fruit label that can be washed away; that leaves no adhesive residue behind; and that helps the end user clean their fruit. It is also desirable to offer a dissolvable fruit label that may be removed by “peeling it off” should the user choose to do so.


Conventional display devices often have the defect of display unevenness (e.g., sometimes referred to as “Mura” or “Trace Mura”) in a part of display regions, Mura is a poor display severely affecting the quality of the picture, the severity and duration of Mura are related to many factors, one is process parameter of the panel, such as liquid crystal, orientation layer, and the like, and the other is the setting of driving conditions. Experimental results show that white state voltage of the liquid crystal is reduced to effectively reduce the severity of the Mura and shorten its duration, wherein the white state voltage refers to the driving voltage of the display device corresponding to the maximal brightness.
The white state voltage of the liquid crystal is reduced to improve the Mura, but certain negative effects shall also be brought. As shown in FIG. 1, the transmittance shall be reduced due to the reduction of the white state voltage, namely, the maximal brightness is reduced, and meanwhile, the reduction of the maximal brightness means contrast reduction. With the reduction of the white state voltage, the variation of the driving voltage of each average grey scale is decreased, so that more accurate driving voltage of the display device is needed, which makes a driver integrated circuit (Driver IC) face more severe working conditions.
To sum up, in the prior art, the white state voltage of the liquid crystal is reduced to improve the Mura, but the maximal brightness shall be reduced, and meanwhile, the driver integrated circuit will face more severe working conditions.


The use of a CATV system to provide internet, voice over internet protocol (“VOIP”) telephone, television, security, and music services is well known in the art. In providing these services, a downstream bandwidth (i.e., radio frequency (“RF”) signals, digital signals, and/or optical signals) is passed from a supplier of the services to a user, and an upstream bandwidth (i.e., radio frequency (“RF”) signals, digital signals, and/or optical signals) is passed from the user to the supplier. For much of the distance between the supplier and the user, the downstream bandwidth and the upstream bandwidth make up a total bandwidth that is passed via a signal transmission line, such as a coaxial cable. The downstream bandwidth is, for example, signals that are relatively higher in frequency within the total bandwidth of the CATV system while the upstream bandwidth is, for example, signals that are relatively lower in frequency.
Traditionally, the CATV system includes a head end facility, where the downstream bandwidth is initiated into a main CATV distribution system, which typically includes a plurality of trunk lines, each serving at least one local distribution network. In turn, the downstream bandwidth is passed to a relatively small number (e.g., approximately 100 to 500) of users associated with a particular local distribution network. Devices, such as high-pass filters, are positioned at various points within the CATV system to ensure the orderly flow of downstream bandwidth from the head end facility, through the trunk lines, through the local distribution networks, and ultimately to the users.
At various locations between the head end facility and the user, there are amplifiers and slope adjustment devices for the purpose of maintaining the quality of the downstream bandwidth. This statement introduces three terms (i.e., quality, amplifiers, and slope adjustment devices) that are important to the remaining discussion. These will be discussed broadly below.
The quality of the downstream bandwidth is often a measure of: (i) a signal level of a particular channel within the downstream bandwidth, the signal level referred to merely as “level;” and (ii) a general consistency of levels across all of the channels in the downstream bandwidth, the general consistency referred to as “slope.” These objective measurements are often used by technicians to evaluate CATV system performance during operation and to troubleshoot customer complaints.
The level of each channel should fall within a specific range that has been determined to provide satisfactory video, sound and information transfer rates for users. The specific requirements for each channel are not of importance to the present discussion, but it is helpful to understand that are specific targets for the level of each channel. Note that this is a simplistic definition to explain “level,” and note that this definition does not include other variances such as between analog and digital.
Slope is measurement used to assess the amount of loss experienced due in large part to cable length. While all channels experience some loss, channels transmitted using higher frequencies within the downstream bandwidth experience more loss than those transmitted using lower frequencies. Accordingly, when the levels for all of the channels within the downstream bandwidth are graphed such that they are arranged in order according to the frequency of the channel, there may be a significant visual downward slope in the graph from the lowest frequency channel to highest frequency channel. This downward slope becomes more prominent as the length of signal cable increases. Note that this is a simplistic definition to explain the consistency of levels across all of the channels and the “slope” that is created by losses occurring in the signal cables. Also note that this definition does not include other variances such as between analog and digital.
The presence of slope is not removed through the use of typical drop-style amplifiers. The drop-style amplifiers merely amplify the entire downstream bandwidth. In other words, these drop-style amplifiers raise the level of each channel equally. In turn, if there is a large amount of slope present, such as when a user's premise includes long distances of signal cable, the drop-style amplifier may cause some channels to exceed their level specification while other channels may remain below their specification.
It is known to add a fixed or manually adjustable slope compensator/low frequency attenuator when there is a long run of signal cable. However, these devices require expensive testing equipment to determine whether and/or how much slope compensation should be supplied to a particular premise. Further, due to the cost of installation and a general misunderstanding regarding how to install such devices, there are relatively few in existence, compared to the number of such devices needed.
For at least the forgoing reasons, a need is apparent for a device, which can increase the overall quality of the downstream bandwidth that includes providing an appropriate amount of amplification and an appropriate amount of slope compensation increasing the signal strength and increasing the signal-to-noise ratio.


The popularity of multiplayer online games on the Internet has exploded in recent years. Unlike conventional single-player electronic games, multiplayer online games enable a player to participate in games with other players, either as an individual or as a team member. The multiplayer aspect of these games adds to the players' gaming experience by offering new gaming considerations, including strategy, teamwork, and rivalries.
In order to enable playing of a multiplayer online game, host services must be provided by either an individual or a third-party host. Host services are typically performed on a host computer or server running a copy of the game, and generally concern controlling overall aspects of the game, such as keeping track of the score and updating the game environment. In addition, the host determines who the game participants are, and whether new players may be added.
Examples of multiplayer online games that are hosted by third-party providers can be found at many gaming web sites, including Microsoft Corporation's Internet Game Zone, which provides a myriad of single player and multiplayer online games that are played by over a half-million users daily. In order to play most of the games on a gaming site, it is necessary for users to download (or procure separately) a copy of the game the user wishes to play. Typically, some of these games may be downloaded for free, while others must be purchased, either online, or at a retail outlet. In addition, many gaming sites offer “premium” games that can only be accessed if the user has paid a membership fee to play such games, or has agreed to pay a usage fee (e.g., an hourly fee, daily fee, etc.).
In addition to Internet gaming site hosts, individuals may also provide hosting services by using their own computer for such purposes. Such a player is referred to as a “host player.” A significant advantage of this configuration is that it generally provides increased performance over games hosted by third-party sites, since the host services for these sites are usually provided by a limited number of servers, each of which is used to simultaneously host a large number of games. In addition, by using one of the game players as the host for the game, the players do not have to pay an access charge to play the game.
In order to facilitate online game playing, it is necessary to enable players to join games already in progress, or enable players to initiate a new game in a manner that allows other players to join in. Oftentimes, players prefer to play games against (or with) players they already know. In general, many of the third-party gaming sites provide host services that make it relatively easy to join games, schedule future games, establish teams, etc. However, there is presently no way to easily initiate game play between players for games that are hosted by individual players.
In order to host a game, the host needs to be able to identify and communicate with all of the game participants. A common scheme for performing this task involves the use of Internet Protocol (IP) addressing. In order to communicate over a communications network, such as the Internet, each device (e.g., a player's computer) connected to the network must be assigned to a unique network address. Under the Internet's present TCP/IP (Transmission Control Protocol/Internet Protocol) scheme (which is also used for other networks), each device connected to the Internet is identified by a 32-bit IP address comprising four 8-bit segments separated by dots, e.g., 207.21.32.212. Each IP address comprises a unique network ID, and a unique host ID, the latter of which identifies a workstation, server, router, or other TCP/IP device on the network. Accordingly, each of the individual computers used by the game players is assigned to its own IP address. As a result, a game host can enable new players to join a game by telling the other players the IP address of the host's machine.
Initiating a game in this matter is burdensome and prone to error. First, all of the players must be apprised of the host's IP address. In general, the host must inform each player of the host's IP address, unless the host uses a computer that is assigned to a static (i.e., permanent) IP address. For example, most game players connect to the Internet via a dial-up online Internet Service Provider (ISP), such as AMERICA ONLINE™, MSN™, COMPUSERVE™, EARTHLINK™, MINDSCAPE™, etc. Each of these ISPs has a fixed number of connections it can use simultaneously, with each connection being assigned to a unique, static IP address. In general, the number of connections (and thus IP addresses) is only a fraction of the number of customers to whom the ISP provides service. Accordingly, the ISPs use dynamic IP addressing schemes, whereby users are dynamically assigned to a connection (and the connection's corresponding IP address) upon logging onto the ISP, and the IP address of the connection is released for use by a subsequent user when the initial user logs off of the ISP. As a result, there is no way to assign a static IP address to users of ISPs of this type. Accordingly, the only way the players can be apprised of the host's IP address is for the host to let them know what the IP address is after it has been assigned, which is typically done through e-mail or via a phone call.
An improvement over the foregoing manual method is provided by online lookup services. In this instance, each member of the online lookup service is assigned a unique alias (i.e., user name) upon signing up for the service, wherein that user is always identified by the alias whenever the user logs onto the lookup service. In addition, upon logging on, the IP address for the user is matched to the user's alias so that the user's IP address can be accessed by application programs running on other computers through use of the alias. As a result, players can then search the online lookup service for the aliases of a host or hosts the players know are or will be hosting a game, wherein the IP addresses of those hosts is passed to the players (generally behind the scenes to an application program running on the player's computer). At this point, the players may still need to manually enter the IP address of the host in order to join the game.
Although the online lookup service scheme is an improvement over the manual method, it is still deficient in many respects. Notably, this scheme doesn't provide a convenient way to invite players to join games, wherein the invited players can decide whether they want to join the game. Additionally, the host must access multiple application programs and perform many steps in order to initiate a multiplayer game. Accordingly, it is desired to provide an improved scheme for enabling individuals to host multiplayer computer games and other players to join such games that overcomes the many limitations of the foregoing manual and online lookup service schemes.


Floating offshore structures such as e.g. oil platforms, offshore wind turbines, and offshore meteorological towers are known.
Several configurations have been proposed for the floating or buoyancy structures: many of these employ floater elements in the form of substantially hollow floater tanks that in use are arranged substantially below the mean sea level and provide a buoyancy force to support the structure, e.g. a wind turbine. Ballast and/or mooring lines anchored to the seabed are provided for achieving stability.
In some of these floating structures, the buoyancy structure is designed to provide an excess buoyancy force and is maintained floating under the mean sea level by taut mooring lines tensioned by the excess buoyancy force.
For example, concepts have been developed such as the “Taught Leg Buoy” (TLB) floating wind turbine, with a slender cylindrical buoy and two sets of tensioned mooring lines, inclined relative to the seabed and connected to gravity anchors and to the buoy; or such as the “Tension Leg Platform” (TLP) floating wind turbine, in which the tensioned mooring lines are substantially vertical and are connected between gravity anchors on the seabed and arms or braces extending radially outwards with respect to the vertical axis of the wind turbine. The TLP arms may be part of the buoyancy structure, for example in the form of hollow spokes that extend radially outward from a hollow central hub, or may be arranged above the sea level, in which case the buoy may be a slender cylindrical tank like in the TLB concept.
TLP structures are also used for offshore oil platforms. Other configurations for offshore structures are not based on providing an excess buoyancy force and tensioned mooring lines for their stability, but instead on having a ballast at a relatively point of the structure. The resulting centre of gravity may thus be located at a relatively low point of the structure as well. As such, the resulting structure may be inherently stable and does not depend on the tensioned mooring lines for stability.
The buoyancy structures of offshore structures are subject to several loads, such as for example the weight of the wind turbine itself, impacts, forces exerted by waves, currents and tides, and, in case of a wind turbine, also aerodynamic forces associated to the wind, rotor rotation, etc.
As mentioned before, the offshore structures that rely on excess buoyancy for stability have tensioned mooring lines or cables. In order for these structures to be stable, the mooring lines must always be under tension, otherwise the offshore structure could become unstable and could fall over. Since the loads on the offshore structures, and particularly on a floating wind turbine may vary considerably both in magnitude and direction, a high amount of excess buoyancy and high tension in the cables may be required.
Having a high tension in the mooring lines or cables means that the cross-sectional area of the cables needs to be increased as well. The resulting cables may thus be heavy and expensive. Additionally, having such a high tension in the cables may result in the rest of the structure to be dimensioned accordingly. Also the other parts of the structure may become heavier and more expensive.
An alternative solution would be to have a high number of lines for providing stability and distributed in such a way that even if some of them could in certain circumstances enter in compression, the other lines would still be able to maintain the stability of the offshore structure. However, also this solution can become very expensive.
There thus exists a need for a floating offshore structure that reduces or resolves at least some of the afore-mentioned problems.


1. Field of the Invention
The present invention generally relates to a program register using a nonvolatile memory device and a programmable logic circuit using the same, and more specifically, to a technology for storing data or performing an operation on the data without additional memory devices, thereby reducing the area of the circuit.
2. Description of the Prior Art
Generally, a ferroelectric random access memory (hereinafter, referred to as ‘FRAM’) has attracted considerable attention as next generation memory device because it has a data processing speed as fast as a Dynamic Random Access Memory DRAM and conserves data even after the power is turned off.
The FRAM having structures similar to the DRAM includes the capacitors made of a ferroelectric substance, so that it utilizes the characteristic of a high residual polarization of the ferroelectric substance in which data is not deleted even after an electric field is eliminated.
The technical contents on the above FRAM are disclosed in the Korean Patent Application No. 1999-49972 by the same inventor of the present invention. Therefore, the basic structure and the operation on the FRAM are not described herein.
A conventional programmable logic operation circuit for changing logic levels of input signals stores address information in storage means. However, since a SRAM (Static Random Access Memory) is used as the conventional programmable logic operation circuit, various information stored in latches is leaked in a power-off mode. Even when power is supplied to the system again, various data for operations of circuits are required to be reset.


This invention relates to radiation curable compositions. More particularly, this invention relates to radiation curable compositions comprising an alkenyl ether functional polyisobutylene, a cationic photoinitiator and a miscible reactive diluent. This invention can further comprise of optional ingredients such as free radical photoinitiator, photosensitizers, non-reactive diluents, thermo-oxidative stabilizers and shelf life stabilizers.
Polyisobutylenes containing functional groups which are radiation curable have been disclosed in the art. For example, T. P. Liao and J. P. Kennedy in Polymer Bulletin, V. 6, pp. 135-141 (1981) disclose acryl and methacryl telechelic polyisobutylenes having the formula CH2xe2x95x90C(R)xe2x80x94COO-PIB-OOCxe2x80x94C(R)xe2x95x90CH2 where R is xe2x80x94H or CH3. These materials were prepared by reacting alpha, omega di-hydroxypolyisobutylene, HOCH2-PIB-CH2OH, and excess acryloyl or methacryloyl chloride. These prepolymers are disclosed as being useful in the synthesis of a variety of new composites containing a soft polyisobutylene segment.
J. P. Kennedy and B. Ivan in Polymer Material Science and Engineering, V. 58, p.866 (1988) disclose allyl telechelic linear and star-branched polyisobutylenes prepared by a convenient rapid one pot polymerization functionalization process. The polymerization step involved living polymerization of isobutylene by recently discovered mono- or multifunctional initiating systems (combinations of tert.-ester and ether/Lewis acids) followed by electrophilic functionalizations by allyl trimethylsilane in the presence of TiCl4. Characterization indicated quantitative end allylations. Subsequent quantitative derivations of the allyl termini yielded mono-, di-, and tri-functional hydroxyl- and epoxy-telechelic polyisobutylenes which could be cured to rubbery networks.
J. P. Kennedy and B. Ivan in the Journal of Polymer Science, Part A, Polymer Chemistry, V. 28, p. 89 (1990) disclose mono-, di-ended linear, and three-arm star allyl telechelic polyisobutylenes which are prepared by a rapid economical one-pot polymerization-functionalization process. The process involved the living polymerization of isobutylene by mono-, di-, or tri-functional initiating systems, specifically by aliphatic and aromatic tert-ester and -ether/TiCl4 combinations, followed by electrophilic functionalization of the living sites with allyl-trimethylsilane. Quantitative derivations of the ally termini yielded mono-, di-, and tri-epoxy and -hydroxy-telechelic polyisobutylenes. It is further disclosed that strong rubbery networks were made by curing the epoxy-telechelic polyisobutylenes with triethylene tetramine and by reacting the hydroxy-telechelic polyisobutylenes with MDI.
J. P. Kennedy, Sandor Nemes and Tibor Pernecker in Polymer Bulletin, V. 25, p.633 (1991) disclose vinyl ether headed polyisobutylenes macromonomers. However no mention was made regarding radiation curable compositions based on these macromonomers. It is known that radiation cured networks from non-telechelic macromonomers will posses poor physical properties.
N. A. Merrill, I. J. Gardner, and V. L. Hughes in RadTech North America Proceedings, V. 1, pp. 77-85 (1992) disclose conjugated diene functional polyisobutylenes which have a high reactivity to both ultraviolet and electron beam radiation. These conjugated diene functional polyisobutylenes, alone or in a formulation, are disclosed as being useful in preparing pressure sensitive adhesives.
In PCT Patent Publication No. WO 9104992 is disclosed a functionalized copolymer of isobutylene and a para-methylstyrene, wherein at least one type of functional group is attached to the para-methyl group of the para-methylstyrene, the copolymer having a substantially homogenous compositional distribution. The functionalized groups are exemplified by alkoxides, phenoxides, carboxylates, thiolates, thiopenolates, thioethers, thiocarboxylates, dithiocarboxylates, thioureas, dithiocarbamates, xanthanates, thiocyanates, silanes, halosilanes, malonates, cyanides, amides, amines, carbazoles, phthalimides, pyridine, maleimide, cyanates, and phosphines.
In PCT Patent Publication No. WO 9211295 is disclosed a radiation reactive functionalized polymer comprising an isoolefin having about 4 to about 7 carbon atoms and a para-alkylstyrene, wherein a radiation reactive functional group is attached to the para-alkyl group of the para-alkylstyrene, and discloses radiation curable pressure sensitive adhesives comprising the functionalized polymer and a tackifier. In WO""295, the radiation curable groups are disclosed as being groups such as thioxanthones, acrylates, aldehydes, ketones, and esters.
Saxena et al. in U.S. Pat. No. 5,665,823 disclose a method for preparing an acrylic functional polyisobutylene polymer or copolymer, the method comprising reacting a polyisobutylene polymer or copolymer which contains at least one carbon-bonded silanol group in it molecule with a silane having both an acrylic-containing group and a silicon-bonded hydrolyzable group in its molecule.
Furthermore, radiation curable compositions which contain vinyl ether functional organosilicon compounds have also been described in the art. For example, Crivello in U.S. Pat. No. 4,617,238 discloses a photopolymerizable composition comprising (a) an organopolysiloxane having at least one Si-bonded vinyloxy functional group of the formula H2Cxe2x95x90CHxe2x80x94Oxe2x80x94Gxe2x80x94, where G is alkylene (such as propylene) or alkylene interrupted by at least one divalent heteroradical selected from xe2x80x94Oxe2x80x94, divalent phenylene, or substituted divalent phenylene, or combination of such heteroradicals, and (b) an onium salt catalyst. The ""238 patent also describes a method wherein the vinyl ether group is introduced into the organopolysiloxane by addition (hydrosilylation) of compounds with an allyl and a vinyl ether group to an SiH group of the organopolysiloxane in the presence of a platinum catalyst. In the method of the ""238 patent, only the allyl group is added to the SiH group while the vinyl ether group is preserved and thus only one vinyl ether group for each SiH group can be incorporated into the siloxane molecule at any given time.
European Patent Publication No. 0462389 teaches thermosetting organopolysiloxanes with oxyalkylene vinyl ether groups bonded by SiOC groups and the vinyl groups may be substituted by alkyl groups. EPO""389 also teaches a method for the preparation of these compounds and their application as photochemically thermosetting polysiloxanes in encapsulating compounds, as non-stick coating compounds for flat carriers or as modified additives in compounds which can be thermoset radically, cationically or by UV or electron radiation.
Brown et al., in U.S. Pat. No. 5,270,423 disclose organosilicon compounds with a siloxane portion of the general formula xe2x80x94ORxe2x80x2OCHxe2x95x90CHRxe2x80x3 linked via an SiOC bond wherein Rxe2x80x2 is a divalent hydrocarbon group and Rxe2x80x3 is hydrogen or an alkyl group which are useful in radiation curable compositions, in which they are mixed with an initiator. The compositions are particularly useful in UV radiation curable coatings.
Glover et al. in U.S. Pat. No. 5,594,042 discloses radiation curable compositions comprising vinyl ether functional siloxanes and aromatic iodonium salt or aromatic sulfonium salt photoinitiators which cure upon exposure to ultraviolet or electron beam radiation. The vinyl ether groups are linked to the silicon atom on the siloxane through an SiOC bond and the photoinitiators are disclosed as being preferably either diaryliodonium salts of sulfonic acids or triarylsulfonium salts of sulfonic acids.
Bujanowski et al. in U.S. Pat. No. 5,629,095 disclose vinyl ether functional siloxane resins, radiation curable coating compositions comprising a vinyl ether functional siloxane resin and a photocleavable acid, and a coated article obtained by applying the radiation curable coating composition to a substrate and then exposing the coating to radiation in an amount sufficient to cure the coating. In the ""095 patent, the vinyl ether group in the siloxane resin is attached to the silicone atom through an SiOC bond.
The present invention relates to radiation curable compositions comprising an alkenyl ether functional polyisobutylene, a cationic photoinitiator and a miscible reactive diluent. The compositions of this invention can further comprise a free radical photoinitiator, photosensitizers, non-reactive diluents for improving the cure speed of the radiation curable compositions, thermo-oxidative stabilizers to improve thermal and oxidative stability of the compositions, and stabilizers for improving the shelf life of the compositions.
It is an object of this invention to produce radiation curable compositions which exhibit a low cure energy.
It is an object of this invention to produce radiation curable compositions which have a high moisture vapor barrier, high damping characteristics, and a high refractive index. It is an object of this invention to produce radiation curable compositions which provide a barrier to corrosive vapors and have maintained or enhanced modulus, tensile strength, and toughness.
This invention relates to a radiation curable composition comprising: (A) an alkenyl ether-functional polyisobutylene polymer in which at least 50 mole percent of the non-terminal repeating units of the polymer are isobutylene units and containing at least one group having the formula
wherein R is independently selected from the group consisting of monevalent hydrocarbon groups and alkoxy groups, R1 is a divalent hydrocarbon group having from 2 to 20 carbon atoms, R2 and R3 are independently selected from the group consisting of a hydrogen atom and a monovalent hydrocarbon group, and a has a value of 0 to 2, (B) a cationic photoinitiator, and (C) a miscible reactive diluent selected from
(i) a difunctional vinyl ether reactive diluent selected from the group consisting of butanediol divinyl ether, pentanediol divinyl ether, hexanediol divinyl ether, heptanediol divinyl ether, cyclohexane dimethanol divinyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, neopentyl glycol divinyl ether, ethoxylated2-20 bisphenol A divinyl ether, poly-THF divinyl ether, bis-(4-ethenyloxy butyl)-succinate, bis-(4-ethenyloxy butyl)-adipate, bis-(4-ethenyloxy butyl)glutarate, bis-((4-((ethenyloxy)methyl)cyclohexyl)methyl)succinate, bis((4-((ethenyloxy)methyl)cyclohexyl)methyl)adipate, and bis-((4-((ethenyloxy)methyl)cyclohexyl)methyl)glutarate; or
(ii) an acrylate reactive diluent with the formula
(R8)Xb
xe2x80x83wherein R8 is a non-silicon containing organic group, X is an organic group containing at-least one acrylate functional group, and b has a value of 2 to 4.
In Component (A), the alkenyl ether-functional polyisobutylene polymer, the monovalent hydrocarbon groups of R are exemplified by alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, octyl, and decyl, aryl groups such as phenyl, tolyl, and xylyl, and can also be any monovalent hydrocarbon group which has at least one of its hydrogen atoms replaced with a halogen, such as fluorine, chlorine, or bromine, and these monovalent hydrocarbon groups are exemplified by CF3CH2CH2xe2x80x94 and C4F9CH2CH2xe2x80x94. The alkoxy groups are exemplified by methoxy, ethoxy, propoxy, and butoxy. It is highly preferred that R is independently selected from the group consisting of methyl and methoxy. Each R group can be the same or different, as desired.
Divalent hydrocarbon groups suitable as R1 are exemplified by alkylene groups such as ethylene, propylene, butylene, pentylene, trimethylene, 2-methyltrimethylene, pentamethylene, hexamethylene, 3-ethyl-hexamethylene, octamethylene, decamethylene, xe2x80x94(CH2)18xe2x80x94, and cycloalkylene groups such as cyclohexylene, arylene groups such as phenylene. Examples of suitable divalent halohydrocarbon groups also include any divalent hydrocarbon group wherein one or more hydrogen atoms have been replaced by halogen, such as fluorine, chlorine or bromine exemplified by xe2x80x94CH2CH2CF2CF2CH2CH2xe2x80x94. Each R1 can be the same or different as desired. Preferably R1 is butylene.
The groups R2 and R3 are independently selected from a group consisting of a hydrogen atom and a monovalent hydrocarbon group exemplified by alkyl groups such as methyl, ethyl, propyl, butyl. The groups R2 and R3 may be the same or different. Preferably R2 and R3 are hydrogen atoms. In the formula above, it is preferred that a have a value of zero.
For the purposes of this invention, the backbone of the alkenyl ether functional polyisobutylene polymer may be any linear or branched polymer or copolymer wherein at least about 50 mole percent, preferably at least 80 mole percent, of the repeat units are isobutylene units having the following structure:
In the polymer or copolymer of the invention, the above described alkenyl ether group can be disposed either along the chain or at the terminals thereof, or any combination of the above. As used herein, the term xe2x80x9cpolymerxe2x80x9d is generic to polymers, oligomers, and copolymers, all of which are within the scope of this invention.
In a preferred embodiment of this invention, the alkenyl-ether functional polyisobutylene polymer (A) is a polymer containing at least one group having the formula
wherein at least 50 mole percent of the non-terminal repeating units of the polymer are isobutylene units, R is independently selected from the group consisting of monovalent hydrocarbon groups and alkoxy groups, R1 is a divalent hydrocarbon group having from 2 to 20 carbon atoms, R2 and R3 are independently selected from group consisting of a hydrogen atom and a monovalent hydrocarbon group, n has a value from 5 to 10,000, a has a value of 0 to 2, and Y is selected from the group consisting of (i) an alkylene group having from 2 to 10 carbon atoms and (ii) a group having the formula
wherein R4 is a monovalent hydrocarbon group, R5 and R6 are independently alkylene groups having from 2to 10 carbon atoms, and m is an integer having a value from 1 to 5.
The groups R and R1 are as defined hereinabove, including preferred embodiments thereof. Preferably, R is independently selected from the group consisting of methyl and methoxy, and R1 is butylene. Preferably, a has a value of 0 or 1.
The alkylene groups of Y(i) are exemplified by ethylene, propylene, butylene, pentylene, trimethylene, 2-methyltrimethylene, pentamethylene, hexamethylene, 3-ethyl-hexamethylene, octamethylene, and decamethylene.
In the formula for Y(ii) above, the monovalent hydrocarbon groups of R4 are as described above for R, and preferably R4 is methyl. The alkylene groups for R5 and R6 are as defined above for Y(i). Preferably, R5 and R6 are independently selected from the group consisting of ethylene and propylene. It is highly preferred that R5 is propylene, and R6 is ethylene. It is also preferred that m has a value of 1.
It is preferred for purposes of this invention that from 10 to 100 weight percent of the alkenyl ether functional polyisobutylene polymer described above be used, and it is highly preferred that from 50 to 100 weight percent of this compound be employed, said weight percent being based on the total weight of the radiation curable composition.
Component (B) in the compositions of this invention is cationic photoinitiator. Suitable cationic photoinitiators are selected from the group consisting of onium salts, diaryliodonium salts of sulfonic acids, triarylsulfonium salts of sulfonic acids, diaryliodonium salts of boronic acids, and triarylsulfonium salts of boronic acids.
The onium salts are preferably selected from the group consisting of R72I+MXZxe2x88x92, R73S+MXZxe2x88x92, R73Se+MXZxe2x88x92, R74P+MXZxe2x88x92, and R74N+MXZxe2x88x92, wherein each R7 is an organic group having from 1 to 30 carbon atoms exemplified by aromatic carbocyclic groups having from 6 to 20 carbon atoms. Each R7 can be substituted with from 1 to 4 monovalent hydrocarbon groups exemplified by alkoxy groups having from 1 to 8 carbon atoms, alkyl groups having from 1 to 16 carbon atoms, nitro, chloro, bromo, cyano, carboxyl, mercapto, and aromatic heterocyclic groups exemplified by pyridyl, thiophenyl, and pyranyl. The symbol M in the formulae hereinabove are metals or metalloids which include transition metals exemplified by Sb, Fe, Sn, Bi, Al, Ga, In, Ti, Zr, Sc, V, Cr, Mn, Cs, rare earth metals exemplified by lanthanides, for example, Cd, Pr, and Nd, and metalloids exemplified by B, P, and As. MXZxe2x88x92is a non-basic, non-nucleophilic anion exemplified by BF4xe2x88x92, PF6xe2x88x92, AsF6xe2x88x92, SbF6xe2x88x92, SbCl6xe2x88x92, HSO4xe2x88x92, ClO4xe2x88x92, FeCl4xe2x95x90, SnCl6xe2x88x92, and BiCl5xe2x95x90.
Preferred onium salts are exemplified by bis-diaryl iodonium salts, for example, bis(dodecyl phenyl)iodonium hexafluoroarsenate, bis(dodecylphenyl)iodonium hexafluoroantimonate, and dialkylphenyl iodonium hexafluoroantimonate.
Diaryliodonium salts of sulfonic acids, triarylsulfonium salts of sulfonic acids, diaryliodonium salts of boronic acids, and triarylsulfonium salts of boronic acids are also suitable as the cationic photoinitiator (B). Preferred diaryliodonium salts of sulfonic acid are diaryliodonium salts of perfluoroalkylsulfonic acids and diaryliodonium salts of aryl sulfonic acids. Preferred diaryliodonium salts of perfluoroalkylsulfonic acids are exemplified by diaryliodonium salts of perfluorobutanesulfonic acid, diaryliodonium salts of perfluoroethanesulfonic acid, diaryliodonium salts of perfluoro-octanesulfonic acid, and diaryliodonium salts of trifluoromethane sulfonic acid. Preferred diaryliodonium salts of aryl sulfonic acids are exemplified by diaryliodonium salts of para-toluene sulfonic acid, diaryliodonium salts of dodecylbenzene sulfonic acid, diaryliodonium salts of benzene sulfonic acid, and diaryliodonium salts of 3-nitrobenzene sulfonic acid.
Preferred triarylsulfonium salts of sulfonic acid are triarylsulfonium salts of perfluoroalkylsulfonic acids and triarylsulfonium salts of aryl sulfonic acids. Preferred triarylsulfonium salts of perfluoroalkylsulfonic acids are exemplified by triarylsulfonium salts of perfluorobutanesulfonic acid, triarylsulfonium salts of perfluoroethanesulfonic acid, triarylsulfonium salts of perfluoro-octanesulfonic acid, and triarylsulfonium salts of trifluoromethane sulfonic acid. Preferred triarylsulfonium salts of aryl sulfonic acids are exemplified by triarylsulfonium salts of para-toluene sulfonic acid, triarylsulfonium salts of dodecylbenzene sulfonic acid, triarylsulfonium salts of benzene sulfonic acid, and triarylsulfonium salts of 3-nitrobenzene sulfonic acid.
Preferred diaryliodonium salts of boronic acids, and triarylsulfonium salts of boronic acids are compounds such as those disclosed in European Patent Application No. 0562922. Preferred diaryliodonium salts of boronic acids include diaryliodonium salts of perhaloarylboronic acids and preferred triarylsulfonium salts of boronic acids are the triarylsulfonium salts of perhaloarylboronic acid.
Preferably the amount of cationic photoinitiator (B) is from 0.01 to 5.0 weight percent based on the total weight of the composition, and it is highly preferred to use from 0.1 to 2.0 weight percent based on the total weight of the radiation curable composition.
Preferably, Component (C)(i) is selected from the group consisting of butanediol divinyl ether, hexanediol divinyl ether, and cyclohexane dimethanol divinyl ether.
Component (C)(ii) in the compositions of this invention is a miscible reactive diluent having the formula
(R8)Xb
wherein R8=a non-silicon containing organic group; X=organic group containing at-least one acrylate functional group; and b=2-4. The R8 group is selected to be the one that is compatible with component (A). The R8 group has between 2 to 30 carbon atoms, and preferably between 4 to 18 carbon atoms. The acrylate functional reactive diluent can be monofunctional, difunctional, or trifunctional.
Component (C)(ii) is exemplified by ethyl acrylate, propyl acrylate, butyl acrylate, tert.-butyl acrylate, tert.-amyl acrylate, hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, isodecyl acrylate, dodecyl acrylate, lauryl acrylate, stearyl acrylate, ethyleneglycol butyl acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, tridecyl acrylate, caprolactone acrylate, 2-phenoxyethyl acrylate, ethoxylated nonyl phenol acrylate, butanediol diacrylate, hexanediol diacrylate, cyclohexane dimethanol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol diacrylate, ethoxylated2-20 bisphenol A diacrylate, poly-THF diacrylate, and trimethylolpropane tri acrylate.
Preferably the amount of miscible reactive diluent (C) is from 1 to 60 weight percent based on the total weight of the composition, and it is highly preferred to use from 5 to 40 weight percent based on the total weight of the radiation curable composition.
Various optional components may be used in the composition beyond Components (A) through (C). The photocuring of alkenyl-ethers is a cationic process. One way known in the art to increase cure speeds of cationic systems is to use one or more free radical photoinitiators and photosensitizers. The use of non-reactive diluents may be required to efficiently disperse the photocatalyst, photoinitiators and photosensitizers into the polyisobutylene matrix.
The free radical photoinitiators for use in the compositions of this invention can be any benzoins exemplified by benzoin alkyl ethers, benzophenone and its derivatives such as 4,4xe2x80x2-dimethyl-amino-benzophenone (Michler""s Ketone), acetophenones exemplified by dialkoxyacetophenones, dichloroacetophenones, and trichloroacetophenones, benzils exemplfied by benzil ketals, quinones, and O-acylated -xcex1-oximinoketones. Preferably the free radical photoinitiator is a compound having the formula
wherein Rxe2x80x2 is selected from the group consisting of xe2x80x94H, an alkoxy group, and a halogen atom, Rxe2x80x3 is selected from the group consisting of xe2x80x94OH, an alkoxy group, and a halogen atom, and Rxe2x80x2xe2x80x3 is selected from the group consisting of xe2x80x94H, an alkyl group, and a halogen atom. Preferred embodiments of this compound are (i) where Rxe2x80x2 is xe2x80x94H, Rxe2x80x3 is xe2x80x94OH and Rxe2x80x2xe2x80x3 is methyl or phenyl, (ii) where Rxe2x80x2 is xe2x80x94H, Rxe2x80x3 is an alkoxy group and Rxe2x80x2xe2x80x3 is phenyl (for benzoin alkyl ethers), (iii) where both Rxe2x80x2 and Rxe2x80x3 are alkoxy groups and Rxe2x80x2xe2x80x3 is phenyl (for benzil ketals), (iv) where both Rxe2x80x2 and Rxe2x80x3 are alkoxy groups and Rxe2x80x2xe2x80x3 is xe2x80x94H (for dialkoxyacetophenones), and (v) where both Rxe2x80x2 and Rxe2x80x3 are xe2x80x94Cl and Rxe2x80x2xe2x80x3 is xe2x80x94Cl or xe2x80x94H (for di- and tri-chloroacetophenones). A preferred free radical photoinitiator is Darocure(copyright) 1173 (2-hydroxy-2-methyl-1-phenyl-propan-1-one).
Preferably the amount of free radical photoinitiator is from 0.01 to 5.0 weight percent based on the total weight of the composition, and it is highly preferred to use from 0.1 to 2.0 weight percent based on the total weight of the radiation curable composition.
Preferred photosensitizers are 2-isopropylthioxanthone or benzophenone.
Preferably the amount of photosensitizer is from 0.01 to 2.0 weight percent based on the total weight of the composition, and it is highly preferred to use from 0.05 to 0.5 weight percent based on the total weight of the radiation curable composition.
Preferred non-reactive diluent are hydrocarbon diluents with C4-20 hydrocarbon chain length; long chain hydrocarbon diluents with epoxy, ester, ether, glycidyl ether, anhydride and carbonyl functional groups. Suitable examples include methyl laurate, methyl nonate, ethyl laurate, dioctyl adipate, di-(2-ethylhexyl)phthalate. di-2-ethylhexyl ether, dioctadecyl ether, dodecylene epoxide, hexyl glycidyl ether, and succinic anhydride.
Preferably the amount of non-reactive diluent is from 0.01 to 2.0 weight percent based on the total weight of the composition, and it is highly preferred to use from 0.05 to 0.5 weight percent based on the total weight of the radiation curable composition.
To improve thermal and oxidative stability of the cured coating one or more stabilizers may be included in the composition. Examples of suitable stabilizers are hindered amines, organic phosphites, hindered phenols and mixtures thereof. Some of the preferred stabilizers are: Irganox(trademark) 1520D; Irganox(trademark) 1010, Tinuvin(trademark) 123 and Tinuvin(trademark) 292.
Preferably the amount of stabilizer is from 0.01 to 2.0 weight percent based on the total weight of the composition, and it is highly preferred to use from 0.05 to 0.5 weight percent based on the total weight of the radiation curable composition.
To improve shelf stability of the un-cured coating one or more stabilizers may be included in the composition. This requires the use of stable photoinitiator compositions as described in the U.S. Pat. No. 5,973,020. These stabilizing agents are usually hindered amines with boiling points of greater than 150xc2x0 C. and preferably greater than 200xc2x0 C. The amine can be a primary, secondary or tertiary amine and preferably a secondary and tertiary amine. Examples are Tinuvin products sold by Ciba-Geigy company, the CYAGARD products sold commercially by Cytec Corporation (Stamford, Conn.) and SANDUVAR products as referenced in the U.S. Pat. No. 5,973,020.
Preferably the amount of stabilizer generally used, by weight in relation to the total weight of the cationic photoinitiator (B) is from 0.01 to 2.0 percent by weight of the cationic photoinitiator solids and preferably between 0.2 to 1.0 weight percent.
The radiation curable compositions of this invention can also contain ingredients exemplified by reinforcing and extending fillers such as treated silicas, hydrocarbon diluents such as linear alkyl dodecylbenzene and functional hydrocarbons such as C8-16 aliphatic glycidyl ethers, colorants, dyes, preservatives, fragrances, and adhesion modifiers.
The radiation curable compositions of this invention can be prepared by mixing the materials described hereinabove and any optional components in any order, using any suitable mixing means, such as a spatula, a drum roller, a mechanical stirrer, a three-roll mill, a sigma blade mixer, a bread dough mixer, or a two-roll mill.
This invention further relates to a method of making a radiation curable composition comprising (I) mixing components (A)-(C) and the optional ingredients described hereinabove. Components (A)-(C) and the optional ingredients are as described above, including preferred embodiments and amounts thereof.
The present invention further relates to a method of making an article of manufacture comprising (I) applying a radiation curable composition comprising components (A)-(C) described hereinabove, to a solid substrate to form a coating, and (II) exposing the coating to an energy source selected from the group consisting of (i) ultraviolet light and (ii) visible light in an amount sufficient to cure the coating.
The composition of (I) can further comprise any of the optional ingredients recited above. Components (A)-(C) and the optional ingredients are as described above, including preferred embodiments and amounts thereof.
The coating may be applied by any suitable manner known in the art, such as by spreading, brushing, extruding, spraying, gravure, kiss-roll and air-knife.
The solid substrate can be a flexible sheet material such as paper, polyolefin film, polyolefin-coated paper, foil, wood, cardboard and cotton, metallic materials such as aluminum, copper, steel and silver, siliceous materials such as glass and stone, and synthetic polymer materials such as polyolefins, polyamides, polyesters and polyacrylates. As to form, the solid substrate can be substantially sheet-like, such as a peelable release liner for pressure sensitive adhesive, a fabric or a foil, or a fiber, or a substantially three-dimensional in form.
Curing itself may be achieved in any of the known ways, including passing a coated substrate under the desired source of radiation, for example a UV lamp, at a predetermined rate and exposing a completely coated substrate to radiation by switching on the required energy source for a predetermined time.
The radiation curable compositions are preferably cured in the form of films. The cured films are expected to have high refractive index, good barrier properties, good adhesion and good damping properties. It is preferable to apply these coatings to surfaces that are adversely affected by exposure to oxygen, moisture vapor and other environmental factors. The radiation curable coatings are particularly useful as high refractive index coatings for optical fibers. The application of the radiation curable compositions to optical fibers and curing of the compositions can be achieved by conventional equipment (see Blyler and Aloisio Polymers for Coating Optical Fibers, Chemtech, November 1987, pages 680-684). The curable compositions can also be used as an additive to compositions whose barrier properties needs to be tailored to higher values. The radiation curable compositions can be used to increase the barrier properties of sealants and pottants used for encapsulating electronic devices that are adversely affected by moisture.


Conventional golf balls can be divided into two general classes: solid and wound. Solid golf balls include one-piece, two-piece (i.e., single layer core and single layer cover), and multi-layer (i.e., solid core of one or more layers and/or a cover of one or more layers) golf balls. Wound golf balls typically include a solid, hollow, or fluid-filled center, surrounded by a tensioned elastomeric material, and a cover.
Golf ball core and cover layers are typically constructed with polymer compositions including, for example, polybutadiene rubber, polyurethanes, polyamides, ionomers, and blends thereof. Ionomers, particularly ethylene-based ionomers, are a preferred group of polymers for golf ball layers because of their toughness, durability, and wide range of hardness values.
Golf ball compositions comprising highly neutralized acid polymers are known. For example, U.S. Patent Application Publication No. 2003/0130434, the entire disclosure of which is hereby incorporated herein by reference, discloses melt-processible, highly-neutralized ethylene acid copolymers and process for making them by incorporating an aliphatic, mono-functional organic acid in the acid copolymer and then neutralizing greater than 90% of all the acid groups present. The use of such compositions in various golf ball layers is disclosed. Also, U.S. Patent Application Publication No. 2005/0148725, the entire disclosure of which is hereby incorporated herein by reference, discloses a highly-resilient thermoplastic composition comprising (a) an acid copolymer, (b) a salt of a high molecular weight, monomeric organic acid; (c) a thermoplastic resin; (d) a cation source; and (e) optionally, a filler. The reference also discloses one-piece, two-piece, three-piece, and multi-layered golf balls comprising the highly-resilient thermoplastic composition.
While various uses for highly neutralized acid polymers in golf balls have been discovered, there is a need in the industry to broaden the applicability of highly neutralized acid polymers to particular golf ball constructions having desirable spin, feel, and COR properties. The present invention provides such golf ball constructions through the use of a layer formed from a low modulus HNP composition and a layer formed from a high modulus HNP composition.


1. Field of the Invention
The present invention relates to a semiconductor memory and, more specifically, to techniques particularly effectively applied to pseudostatic RAMs (random access memories).
2. Description of the Related Art
A known pseudostatic RAM is designed on the basis of a dynamic RAM which can be constructed in a large scale of integration, and has an interface compatibility with an ordinary static RAM. The pseudostatic RAM has, in addition to an ordinary read/write mode, an address refresh mode and an autorefresh mode in which a refreshing action is executed once in response to an external control action, and a self-refresh mode in which a self-controlled refreshing action is executed periodically, for example, while the pseudostatic RAM is backed up by a battery. The pseudostatic RAM is provided internally with a refresh counter for sequentially specifying word lines for refreshing action in the autorefresh mode and the self-refresh mode, and a refresh timer circuit for periodically starting the refreshing action in the self-refresh mode.
The pseudostatic RAM having the autorefresh and self-refresh modes is described, for example, in "Hitachi IC Memory Data Book", Hitachi, Ltd., pp. 229-234, March, 1987.
The mean current consumption of the memory arrays of the pseudostatic RAM or the like in the self-refresh mode increases approximately in proportion to the reciprocal of the refresh period, i.e., the number of refresh cycles in a unit time. The refresh period in the self-refresh mode is dependent on the intrinsic information holding ability of the memory cells and the stability of the refresh timer circuit for setting the refresh period. Such conditions are restrictions on the reduction of the power consumption of the pseudostatic RAM or the like in operation backed up by batteries.
Prior to the present invention, the inventors of the present invention intended to stabilize the refresh period of the pseudostatic RAM and to increase the refresh period as near to the intrinsic information holding ability of the memory cells as possible by constructing the refresh timer circuit of an oscillation circuit, which is less dependent on the supply voltage, and a refresh timer counter circuit which counts the pulses of a pulse signal provided by the oscillation circuit and generates a predetermined refresh start signal, and by selectively opening corresponding fuse means to set an optional initial count for the refresh timer counter circuit.
However, the operating current of the oscillation circuit is limited, and the oscillation circuit needs a capacitor having a comparatively long charging or discharging period, and a comparatively large resistance, hence a comparatively long polycrystalline silicon resistor must necessarily be formed on a semiconductor substrate. Accordingly, the discharge current varies or the bumping (varying) of the supply voltage cannot be absorbed rapidly due to a large substrate capacitance, which is parasitic to the semiconductor substrate and the polycrystalline silicon resistor causing the variation of the frequency of oscillation of the oscillation circuit, for example, when the supply voltage applied to the oscillation circuit bumps (varies) during the discharge period of the capacitor. Therefore, the frequency of oscillation of the oscillation circuit must have a margin in relation with the information holding ability of the memory cells.
Although the oscillation circuit and refresh timer counter circuit of the pseudostatic RAM is capable of selectively changing the refresh period of the pseudostatic RAM, there is no means for testing and confirming the oscillation characteristics and variation characteristics. Accordingly, the refresh period is set inevitably by a trial-and-error method unless data of those characteristics is available. This fact, similarly, requires the frequency to be set with a margin in relation with the information holding ability of the memory cells, restricts the reduction of the power consumption of the pseudostatic RAM and increases the amount of work required for testing the pseudostatic RAM.


The ability of a polished surface to return to its original appearance after being smeared and the amount of time required to do so are two factors which tend to be rather important in the evaluation of the performance of a furniture polish composition.
Upon application onto a particular substrate surface, the polish compositions of the present invention have been observed to form a rather thin (approximately 1000 to 4000 Angstroms) generally uniform film on the substrate surface. Due to the liquid nature of the resultant films of the surface-applied emulsion polish compositions of the present invention, such films typically exhibit, to a degree, visible physical evidence of surface disturbances, otherwise referred to as surface "smears", when the surface-applied film is subjected to a rubbing action.
The term "smear recovery", as used herein, denotes not only the rate-of-recovery but also the ability of a thus "smeared" surface-applied polish film to return to its original surface appearance.
Polish compositions possessing superior smear recovery properties have long been desired. Conventional polishes, however and in particular the surface-applied films they produce lack this quality. For example, commercial polishes that use conventional silicone-containing or conventional silicone-based fluids, as well as certain conventional waxes, and certain low molecular weight organic oils as glossing agents seemingly initially tend to provide certain desirable surface-appearance values but, in fact, ultimately suffer from certain inherent disadvantages. Such conventional polishes, in particular, readily tend to show certain surface disturbances such as fingerprints and otherwise readily tend to smear.
Certain investigations discussed in the prior-art references reviewed by us have attacked these and other surface "smear" problems by attempting to produce specific smear-resistant polishes which are said to provide treated surfaces that have relatively permanent finishes. Such so-called "permanent" finishes are said to require the application of significant force before their surface properties are disturbed. While such finishes tend to provide both high gloss and smear resistant properties, it is generally more difficult to remove these so-called "permanent" finishes; and such finishes thus have the tendency to build up with multiple applications.
Smear resistant films of this type are described e.g. in U.S Pat. No. 3,847,622 to Brandl et al. The disclosed compositions of Brandl et al. contain water, wax, a mixture of organopolysiloxanes a solvent, and a water-in-oil emulsifier. Such compositions furthermore, are said to be substantially devoid of any tendency to smear or streak and are further said to be easily applied with a minimum of physical effort. Brandl et al. teach however that the use of silicones of diverse types, i.e. organopolysiloxanes, while beneficial from the standpoint of luster, gloss and durability nevertheless fail to provide appreciable mitigation of the smear problem as they view it. The emulsion polish compositions disclosed by Brandl et al. are thus said to possess a "particularly high resistance to smearing."
In U.S. Pat. No. 3,856,533, Schnurrbusch et al. disclose certain wax-containing surface-polish compositions which are said to be resistant to "finger-marking". Such compositions are disclosed as containing an organopolysiloxane (such as dimethylsiloxane), a wax, and a specified so-called "organosiloxane" containing an alkyl, an alkenyl, or a monocyclic aryl radical.
The present invention, in contradistinction to the prior art briefly discussed hereinabove, approaches the so-called "smear problem" in a manner which is markedly different from the approach set forth either in U.S. Pat. No. 3,847,622 to Brandl et al. or in U.S. Pat. No. 3,856,533 to Schnurrbusch et al. The present invention, in particular, enhances the smear-recovery properties of the emulsion polish compositions disclosed herein. Indeed, the unexpected and significant increase in smear recovery which is attributable to the polysiloxane copolymers of our present invention, is shown in the comparative-example data presented hereinbelow. In particular, the smear-recovery properties of the novel emulsion polish compositions disclosed herein were not recognized by any of the prior-art polish formulators whose work we reviewed
The prior-art references which we reviewed while disclosing numerous furniture polishes using polysiloxanes, thus do not teach, disclose or even suggest the novel polysiloxane copolymers of our present invention. In particular, and as mentioned above, the novel polysiloxane copolymers of our invention have been demonstrated, by comparative example, as being unexpectedly superior over prior-art polysiloxanes such as polydimethylsiloxane. Indeed, it was only through our present discovery that the surprising smear-recovery properties of the emulsion polish compositions of the present invention came to light.
In U.S. Pat. No. 2,698,805 to Currie et al., for example, there are disclosed certain conventional polishes which are said to be easy to apply. Such conventional emulsion polish compositions contain a hydrocarbon-soluble organopolysiloxane having from 1 to 3 aryl, alkyl, or arylkyl radicals per silicon atom. Such emulsion polish compositions further include a hydrocarbon solvent a specified aluminum stearate compound, and water. The alkyl radicals which Currie et al. disclose are methyl, ethyl, propyl and octadecyl. The polish compositions disclosed by Currie et al., furthermore, are said to be smear-free. In contradistinction, the polish compositions of our present invention do indeed smear; but, upon being smeared, recover more rapidly than conventional compositions containing conventional polydimethylsiloxane polymers of comparable viscosity and/or weight-average molecular weight relative to the above-mentioned polymeric siloxanes disclosed herein.
Indeed the concept of rapid smear recovery is not disclosed or even suggested by Currie et al. Moreover, the preferred organopolysiloxane disclosed in the Currie '805 patent, namely dimethylpolysiloxane fluid, is shown hereinbelow as being inferior to the siloxane-containing compositions of the present invention with regard to smear-recovery properties.
Further, U.S. Pat. No. 2,523,281 to Currie, is directed to automobile polishes containing an organopolysiloxane having from 1 to 3 aryl, alkyl or alkaryl radicals per silicon atom. Such automobile polishes also include a hydrocarbon solvent, finely-divided silica of a specified particle size, an emulsifying agent, and water. The disclosed alkyl radicals include methyl, ethyl, propyl, and octadecyl. Disclosed in this patent, furthermore, as the preferred organo polysiloxanes, are certain dimethylpolysiloxanes which are shown hereinbelow as possessing inferior smear-recovery properties as compared to those siloxanes utilized in accordance with the principles of the present invention.
Still other patents, disclosing the use of polysiloxanes in furniture-care compositions, do not disclose the novel emulsion polish compositions of the present invention. In particular, U.S. Pat. Nos. 4.163.673 to Dechert; 4,354,871 to Sutton; and U.S. Pat. No. 4,613,646 to Sandvick all disclose that dimethyl polysiloxane or polydimethyl siloxane is an especially-preferred polysiloxane for use in furniture polish compositions. Such siloxanes however form no part of the novel emulsion polish compositions of the present invention.
Indeed, the prior art does not disclose or even suggest the specific poly(dimethyl)-co-poly(methylalkyl) siloxane and poly(dimethyl)-co-poly(methyl, oxygen-containing) siloxane copolymers of the present invention; nor does the prior art disclose or even suggest the unexpected smear-recovery properties of compositions containing the siloxane copolymers of the present invention.
For example, U.S. Pat. No. 4,404,035 to Ona et al. discloses wax compositions comprising certain hydrocarbon ester-containing organopolysiloxanes, i.e. specified organopolysiloxanes containing at least one silicon-bonded hydrocarbon-ester group. The Ona et al. patent does not, however, teach or even suggest the usefulness of alkylene oxide polysiloxanes. Ona et al., in particular, teach away from using alkylene oxide polysiloxanes, as is shown by way of their so-called "solution D", as presented in their Example 2. That is, Ona et al., in their Example 2, specifically report that a polysiloxane having a side chain containing an alkylene oxide having the following formula EQU (CH.sub.2).sub.3 O(C.sub.2 H.sub.4 O).sub.20 (C.sub.3 H.sub.6 O).sub.20 H
produced a coating on a metal panel which, after being subjected to a 20-hour water shower, was deemed to be unacceptable in luster, water-repellency and durability.
In U.S. Pat. No. 4,218,250 to Kasprzak, there is disclosed a wax-containing and/or abrasive-containing formulation which includes a cyclodimethyl siloxane fluid and a polydiorgano siloxane polyoxyalkylene copolymer. The disclosed polish formulation may also include a specific silicon-glycol copolymer having the following formula EQU (CH.sub.3).sub.3 SiO[(CH.sub.3).sub.2 SiO].sub.x [G(CH.sub.3)SiO].sub.y Si(CH.sub.3).sub.3
wherein x has an average value of 0 to 10, y has an average value of 1 to 10, G has the formula, --D--(OC.sub.2 H.sub.4).sub.z OH, with D being an alkylene radical containing from 2 to 10 carbon atoms and z having an average value of from 6 to 20. This patent, however, does not mention smear resistance or smear recovery; nor does this patent otherwise disclose either the specific poly(dimethyl)-co-poly(methylalkyl) siloxane or poly(dimethyl)-co-poly(methyl, oxygen-containing) siloxane copolymers of the present invention.
Additionally U.S. Pat. No. 3,306,869 to Lahr et al. discloses floor polishes which are said to possess desirable so-called "leveling" properties as well as acceptable "scuff-resistance" properties. Such floor polishes comprise a wax, a modified rosin, an emulsifying agent, and a polysiloxane-oxyalkylene block copolymer having a molecular weight below about 25,000 and a polysiloxane content in the range of from about 30 to about 60 percent by weight. U.S. Pat. No. 3,341,338 to Pater also discloses a polish formulation comprising a polysiloxane-oxyalkylene block copolymer and a wax. Neither patent, however, discloses or even suggests "smear recovery", or otherwise discloses the specific poly(dimethyl)-co-poly(methylalkyl) siloxane or poly(dimethyl)-co-poly(methyl, oxygen-containing) siloxane copolymers of our present invention.
From the above discussion, it can either be implied that the smear-recovery problems associated with certain prior-art polish compositions are not appreciated or, if such problems have become recognized by those skilled in the art, it can be implied that an acceptable solution to the smear-recovery problem is still generally unknown to those skilled in the art.
Accordingly there is presently a need for polish compositions which possess rapid smear-recovery properties. One object of our invention, therefore, is to provide polish compositions for furniture and other similar household items, wherein such polish compositions exhibit rapid smear-recovery qualities.
It is yet another object of our invention to provide furniture polish compositions which may be applied and removed with a minimum of effort, and which possess not only rapid smear-recovery properties but also acceptable so-called "depth-of-gloss" characteristics as well.
The foregoing, as well as other objects, features and advantages of our invention will become more readily clear to those skilled in the art upon reference to the following summary and detailed description.


The present invention relates to a swash plate type compressor that has single headed pistons and is used in an air conditioner of a vehicle, and more particularly, to improvement of a radial bearing that supports a drive shaft for reciprocating the pistons and to improvement of a lubricating structure of a shaft sealing assembly.
As shown in FIG. 6, the housing of a typical swash plate type compressor includes a front housing member 71, a cylinder block 72 and a rear housing member 73, which are secured to one another. A drive shaft 74 has a first end and a second end. The drive shaft 74 is supported by the housing through a first and second radial bearings 75, 76 such that the first end protrudes from the front housing member 71. A shaft sealing assembly 78 is located about the drive shaft 74 at a position between the first end and the first radial bearing 75. The sealing assembly 78 prevents refrigerant gas from leaking from a crank chamber 77 to the atmosphere.
Moving parts of a compressor such as bearings are lubricated by misted lubricant contained in refrigerant gas. Therefore, parts where refrigerant gas is stagnant are not effectively lubricated. A compressor that uses carbon dioxide (CO2) for a cooling circuit instead of chlorofluorocarbon has been introduced. When using CO2 as refrigerant, the refrigerant pressure is more than ten times that of a case where chlorofluorocarbon is used as refrigerant, which increases the load acting on bearings and shaft sealing assemblies. Accordingly, lubrication must be improved.
In the compressor of Japanese Unexamined Patent Publication No. 11-241681, the shaft sealing assembly 78 is located in an isolated chamber 80, which is forward of the first radial bearing 75. A decompression passage 79 is formed in the drive shaft 74. An outlet 79b of the decompression passage 79 opens to the end face of the second end of the drive shaft 74. A fan 81 is attached to the second end of the drive shaft 74. When the fan 81 rotates integrally with the drive shaft 74, refrigerant in the decompression passage 79 is drawn to the outlet 79b. The refrigerant then flows to the crank chamber 77 through the radial bearing 76.
The isolated chamber 80 is connected to the crank chamber 77 through the space in the radial bearing 75 and the space in a thrust bearing 82. The spaces in the radial bearing 75 and the thrust bearing 82 function as oil supplying passages.
Japanese Unexamined Patent Publication No. 8-165987 discloses a compressor shown in FIG. 7. In this compressor, a second end of the drive shaft 74 faces a chamber 84 that communicates with a suction chamber 83. An axial passage 85 is formed in the drive shaft 74. The inlet 85a of the passage 85 opens to an isolated chamber 80. The outlet 85b of the passage 85 opens to the chamber 84.
In the compressor of FIG. 6, the fan 81 attached to the drive shaft 74 draws some of refrigerant gas into the decompression passage 79 through the first radial bearing 75 or through the thrust bearing 82. The drawn refrigerant gas then returns to the crank chamber 77 through the second radial bearing 76. Accordingly, the radial bearings 75, 76 and the shaft sealing assembly 78 are reliably lubricated. However, to flow lubricant through the decompression passage 79, the fan 81 is required, which complicates the structure.
Instead of a fan, the chamber 84 is located adjacent to the second end of the drive shaft 74 of the compressor shown in FIG. 7, and the passage 85 is formed in the drive shaft 74 to connect the isolated chamber 80 with the chamber 84. Thus, refrigerant flows through the radial bearings 75, 76 or through the thrust bearing 82 in accordance with the pressure difference between the crank chamber 77 and the chamber 84. However, since the inlet 85a is located between the shaft sealing assembly 78 and the thrust bearing, flow of refrigerant is weakened either in the shaft sealing assembly 78 or in the thrust bearing, which results in insufficient lubrication.
Accordingly, it is an objective of the present invention to provide a swash plate type compressor that includes a simple structure for effectively lubricating radial bearings, which support a drive shaft, and a shaft sealing assembly.
To achieve the foregoing and other objectives and in accordance with the purpose of the present invention, a swash plate type compressor is provided. The compressor includes a housing, a drive shaft, first and second radial bearings, a piston, a cam plate, a shaft sealing assembly. A suction chamber, a discharge chamber and a crank chamber are defined in the housing. The housing has at least one cylinder bore. The drive shaft is rotatably supported by the housing and has a first end portion and a second end portion. The first end portion protrudes from the housing. The first and second radial bearings support the first and second end portions of the drive shaft, respectively. The piston is reciprocally accommodated in the cylinder bore. The cam plate is accommodated in the crank chamber and is operably coupled to the piston to convert rotation of the drive shaft into reciprocation of the piston. The shaft sealing assembly seals the space between the drive shaft and the housing and is accommodated in the suction chamber. The suction chamber is closer to the first end portion of the drive shaft than the first radial bearing is. A passage is formed in the drive shaft to connect the suction chamber to the crank chamber. The passage has an inlet and an outlet. The inlet is closer to the second end portion than the second radial bearing is. The outlet is closer to the second end portion than the first radial bearing is.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.


The disclosed embodiments generally relate to optical communication links and laser optical ranging, and in particular, to optical communication links and laser optical ranging between extraterrestrial bodies.
In space based optical communication and ranging, pointing, or attitude precision is critical as it directly affects the communication link power budget, communication link power fluctuations and the size, weight, and power of the communication or ranging instrumentation. In most examples, the communication link and communication and ranging instrumentation may use optical beams, in particular, lasers. Because of the distances between a space craft and a target, for example, Earth, and the coherence of the optical beam, pointing errors in the micro-radian range may result in missing the target.
A star tracker may be used to determine the attitude of the space craft with respect to the stars. Because the positions of many stars have been accurately measured over the years, a camera may be used with a database of star locations and patterns to determine and adjust the orientation of the spacecraft. The accuracy of the control systems used for attitude adjustment may limit the pointing accuracy. For example, present reaction wheel attitude control systems may limit pointing accuracy to approximately 50 micro-radians. Attitude dynamics, atmospheric drag, magnetic fields, solar radiation pressure, gravity gradients, vibration, and heating and cooling effects may also affect the ability of a space craft attitude control system to maintain a particular attitude in order to accurately direct a communication or ranging beam toward a target.
It would be advantageous to improve provide a system that improves laser beam pointing accuracy to the level of that of the start tracker pointing knowledge so the overall pointing accuracy will not be limited by the accuracy of the control systems used for attitude adjustment.


1. Field of the Invention
The present invention relates to an information recording medium drive control apparatus applied to an information processing apparatus provided with a drive that allows the change of information recording mediums.
2. Description of the Related Art
In recent years, information processing apparatuses, such as portable computers, incorporating CD-ROM (Compact Disc Read-Only Memories) drivers have been popularized. CD-ROMs that are capable of driving optical disc drives provided in such information processing apparatuses include music CD-ROMs, photo CD-ROMs, video CD-ROMs, video-game CD-ROMs, car navigation CD-ROMs, and movie CD-ROMs.
Since these CD-ROMs each have the information recorded in a different format, to read the information from a CD-ROM requires a player compatible with the format of the CD-ROM. To meet this requirement, some commercially available information processing apparatuses of recent date are provided with several types of players so that various types of CD-ROMs can be played back. These players are offered in software form and normally consist of application program modules.
Referring to a flowchart in FIG. 1, the process of playing back a CD-ROM will be explained.
First, to play back a CD-ROM, the user chooses item "CD" on the screen of a display (step A1). This causes a selection menu for prompting the user to choose the type of a CD-ROM to appear on the screen of the display (step A2). The selection menu contains various items including music, photo, video, game, car navigation, and movie, for example. If the user chooses "PHOTO," for example (step A3), the photo player (application program) stored in a ROM or the like is loaded into a main memory (step A4).
Next, the user inserts a photo CD-ROM into the drive of the electronic apparatus (step A5). The drive drives the CD-ROM automatically and brings it in steady rotation (step A6). Then, the photo player performs the playback process by reading the information from the CD-ROM (step A7).
As seen from the processing flow, to play back the desired CD-ROM, the user has to choose a suitable one from the players. Because of this, the user feels that the selection of a player is troublesome. In a case where playback must be performed rapidly, the user may feel that it takes a long time to complete the selection.
Furthermore, after the selection of the player has finished, the user does not necessarily insert a suitable CD-ROM into the drive. Because the user might insert the wrong CD-ROM by mistake, he or she is always nervous when inserting a CD-ROM, worrying about making a mistake. If the wrong type of CD-ROM is inserted, malfunction may result. When a malfunction has occurred or the playback has not been performed due to the insertion of the wrong type of CD-ROM, the user may waste time until the cause of the malfunction has been corrected.
Recently, DVDs (digital video discs), whose specification differs from that of conventional CDs, have begun coming onto the market. The types of information recording mediums dealt with by personal computers or the like are expected to increase in number. With many types of players being available, the user will have to choose a suitable one from the many types of players, he or she is more liable to choose the wrong player by mistake, making the selection work more troublesome.
To overcome these problems, there have been demands for the techniques for, when an information recording medium is played back, automatically choosing a player compatible with the type of the information recording medium inserted in the drive without the user choosing the player.
Now, the process of changing the CD-ROM being played back will be described.
The photo player is now playing back a photo CD-ROM (step B1). To change the photo CD-ROM to a music CD-ROM, the us e r stops the playback operation of the photo player (step B2) and ejects the photo CD-ROM from the drive (step B3). The user chooses the music player corresponding to music CD-ROMs (step B4) and inserts a music CD-ROM into the drive (step B5). This causes the music player to play back the music CD-ROM (step B6).
As seen from the processing flow, to change the photo CD-ROM, the user must stop the playback operation of the photo player. If the user does not stop the player or carries out an operation different from the stop operation by mistake, the following problem will arise. Even after the photo CD-ROM has been changed to a music CD-ROM, the photo player keeps playing pack as it has done. This permits the music player and photo player to read the information from the music CD-ROM at the same time, resulting in malfunction.
To overcome this problem, there have been demands for the techniques for, when an information recording medium being played back is changed, automatically stopping t he player corresponding to the information recording medium ejected from the drive without the user stopping the player.