Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/14—Polycondensates modified by chemical after-treatment
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/68—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the catalysts used
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/18—Manufacture of films or sheets
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/16—Nitrogen-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L1/00—Compositions of cellulose, modified cellulose or cellulose derivatives
  • C08L1/08—Cellulose derivatives
  • C08L1/10—Esters of organic acids, i.e. acylates
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins
• • G02B1/105—
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
  • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
  • G02B1/14—Protective coatings, e.g. hard coatings
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2301/00—Characterised by the use of cellulose, modified cellulose or cellulose derivatives
  • C08J2301/08—Cellulose derivatives

Definitions

• the present invention relates to a cellulose ester • film, a polarizing plate and a liquid-crystal display device .
• cellulose ester films are transparent, have excellent physical and mechanical properties, and exhibit a small dimensional change against temperature and humidity changes, they have hitherto been used in a variety of fields such as bases for photographic films, tracing films for drawing, and electric insulating materials. Recently, they have been used as polarizing plates for use in liquid-crystal display (LCD) , protective films or optically-compensatory film supports for circular polarizing plate for use in organic EL display, and retardation films. On the other hand, since LCD is thin, light, and small in electric power consumption, it has been widely used instead of CRT. Accordingly, demands for these retardation films and polarizing plates are increasing as LCD comes into wide use. Its use has also been expanded from conventional small articles such as electronic calculators and watches to large articles such as automobile meters, PC monitors, and televisions.
• the retardation films and polarizing plates are apt to be physically damaged and quality of displaying images are deteriorated when they are damaged, so that it is desired to increase mechanical strength thereof. Furthermore, it has been desired to have such a long-term durability that image quality of LCD is hardly deteriorated even when LCD is used for a long period of time under an environment where temperature and humidity may change.
• a protective layer is generally attached to both faces or one face of a polarizer having polarizability via an adhesive layer.
• a material for the polarizer polyvinyl alcohol (hereinafter referred to as PVA) is mainly used. After a PVA film is subjected to monoaxial stretching, it is dyed with iodine or a dichroic dye or stretched after dyeing, and further it is crosslinked with a boron compound, whereby a polarizer is formed.
• PVA polyvinyl alcohol
• the protective layer mainly a cellulose ester, especially cellulose triacetate (TAC) is employed since it is necessary for the layer to be optically transparent and small in birefringence and have a smooth surface. Also for the other optical films, cellulose acetate is employed.
• cellulose triacetate is, for example, used as a protective layer
• moisture penetrated through the protective layer influences components constituting the polarizer, such as iodine, to decrease polarizability of the polarizer under a long-term high-temperature and high humidity environment and a problem that deformation may occur at high temperature and high humidity.
• a technology for lowering water vapor permeability of cellulose triacetate films and the other cellulose esters films and a technology for mechanically strengthening them have been desired.
• JP- A-2004-109307 Against the problems, there is a description in JP- A-2004-109307 that the above problems are remedied by converting the cellulose into three-dimensionally crosslinked cellulose utilizing remaining hydroxyl groups in the cellulose ester films through incorporation of a crosslinking agent.
• cellulose ester films are usually reproduced by dissolving used films thereof and sub-standard films generated during production steps in a good solvent and then reused from the viewpoints of efficient use of resources and cost reduction.
• cellulose is three-dimensionally crosslinked as above, there arises a problem that it is impossible to reuse the cellulose because of its insoluble nature. Therefore, a method which allows reuse of cellulose and also is effective is desired.
• JP-A-2004-109307 the polymerization accelerator to be used in the invention is not described.
• a sheet comprising a norbornene-based resin is useful as a protective film (protective layer) of polarizers (JP-A-10-101907) .
• the sheet comprising a norbornene-based resin has a sufficiently small water vapor permeability but its adhesiveness with a polarizer is insufficient, so that the sheet is not yet satisfactory as a protective layer.
• JP-A-2004-285159 discloses a transparent film comprising a semi-IPN (semi- interpenetrating network structure) type polymer alloy of a cellulose ester and a crosslinked polymer.
• the technology disclosed in JP-A-2004-285159 includes a crosslinked polymer obtained by photo-polymerization of a low-molecular-weight compound having a polymerizable unsaturated double bond but the low-molecular-weight compound is highly toxic and volatile and hence there is a fear that pollution may occur during its production steps.
• the photo-polymerization requires a large-scale production equipment and hence a current production facility should be widely changed in some cases.
• An object of the invention is to provide a cellulose ester film which is (1) less apt to cause deterioration of planarity, (2) less apt to absorb moisture, (3) low in water vapor permeability and excellent in storability, (4) capable of reuse since formation of three- dimensionally crosslinked cellulose ester can be minimized, and (5) excellent in productivity.
• Another object of the invention is to provide a polarizing plate and a liquid-crystal display device constituted using the cellulose ester film.
• a cellulose ester film comprising: a cellulose ester; and a reaction product between at least one epoxy compound and at least one polymerization accelerator.
• a cellulose ester film obtained by a method comprising: casting a solution comprising a cellulose ester, ' at least one epoxy compound and at least one polymerization accelerator; and then subjecting the casted solution to heat treatment at 70°C or higher, wherein the cellulose ester is substantially not three-dimensionally crosslinked.
• R 1 , R 2 and R 3 each independently represents an alkyl group or a halogen atom
• L 1 and L 2 each independently represents a divalent aliphatic organic group
• M represents an oxygen atom or a nitrogen atom
• A represents a m-valent connecting group; a, b and c each independently represents an integer of from 0 to 4; x and y each independently represents a real number of from 0 to 20;
• 1 represents 1 or 2; and m represents an integer of from 2 to 4.
• cellulose ester film as described in any of (1) to (6) above, wherein the cellulose ester is a triacetyl cellulose, a cellulose acetate propionate or a cellulose acetate butyrate.
• a polarizing plate comprising: a polarizer; and at least one protective layer of the polarizer, wherein the at least one protective layer comprises a cellulose ester film as described in any of (1) to (7) above .
• a liquid-crystal display device comprising a cellulose ester film as described in any of (1) to (7) above .
• a liquid-crystal display, device comprising a polarizing plate as described in (8) above.
• an alkyl group having 1 to 3 carbon atoms is preferred and the halogen atom includes Br, Cl, F, or the like.
• variable numbers x, y and n each is a real number and may be any number as far as each of them is in the range of from 0 to 20 .
• the reason why x, y and n are not always integers is that epoxy compounds having several kinds of integer values are mixed in a certain ratio and the numbers represent average values thereof .
• These epoxy compounds may be used solely or in combination with two or more thereof .
• epoxy compounds other than the structures represented by the formulae (I) to (IV) the following compounds may be mentioned:
• the polymerization accelerator is a compound which accelerates the polymerization (or crosslinking) reaction of the epoxy compounds and does not substantially three- dimensionally crosslink the cellulose ester.
• the polymerization accelerator induces the condensation reaction of the accelerator itself with the epoxy compound and acts as a catalyst to accelerate the reaction of the epoxy compounds themselves, whereby a network structure is formed in the cellulose ester.
• the polymerization accelerator there may be mentioned substituted or unsubstituted amines, imidazoles, mercaptans, acid anhydrides, polyamide resins, organic acid hydrazides, and the like.
• at least one compound selected from the group consisting of amine derivatives, acid anhydrides, and imidazole derivatives is preferred.
• polysulfide resin Thine Bond 2104 manufactured by Three Bond
• ethylene glycol bistrimellitate ethylene glycol bistrimellitate
• glycerol tristrimellitate ethylene glycol bistrimellitate
• the polymerization accelerator is not limited thereto.
• bifunctional- amine derivatives are most preferred since they form network structures without crosslinking the cellulose ester.
• the presence of the three- dimensional crosslinking in the cellulose ester can be judged by immersing" the cellulose ester in a solvent capable of dissolving the cellulose ester, e.g., methylene chloride, and determining whether the cellulose ester is dissolved therein.
• cellulose ester is substantially not three-dimensionally crosslinked herein means that the ratio of crosslinking of the hydroxyl group (an unreacted hydroxyl group is not present in the case that degree of substitution is 3.0) in the cellulose ester is 5% or less. The ratio is preferably 3% or less, most preferably 1% or less.
• the ratio of crosslinking of the hydroxyl group present in the cellulose ester can be calculated by a method of detecting OH group on NMR.
• the amount of the epoxy compound to be used is preferably from 1% to 30% based on the mass of the cellulose ester.
• the amount is more preferably from 2% to 20%, further preferably from 3% to 15%. (In this specification, mass ratio is equal to weight ratio.)
• the mount of the polymerization accelerator to be used is preferably from 1% to 100%, more preferably from 5% to 50%, even more preferably from 10% to 40% based on the mass of the epoxy compound to be used.
• cellulose esters such as triacetyl cellulose (TAC) , diacetyl cellulose (DAC) , cellulose acetate propionate (CAP) , cellulose acetate butyrate (CAB) , cellulose acetate phthalate, cellulose acetate trimellitate and cellulose nitrate.
• TAC triacetyl cellulose
• DAC diacetyl cellulose
• CAP cellulose acetate propionate
• CAB cellulose acetate butyrate
• cellulose acetate phthalate cellulose acetate trimellitate
• cellulose nitrate cellulose nitrate
• the above cellulose esters are preferably used for the cellulose ester film of the invention. More preferably, with regard to the degree of substitution of the cellulose ester, when the degree of substitution with an acyl group is represented by X, X is preferably from 2.5 to 3.0, more preferably from 2.7 to 3.0, most preferably from 2.9 to 3.0. When the degree of substitution is high, there is no risk of crosslinking the cellulose and it is possible to prepare a dope having a high concentration (hereinafter, a solution wherein a cellulose ester, an epoxy compound, a polymerization accelerator, and the like are dissolved in a solvent is referred to as dope) , so that the case is advantageous for film formation and drying and preferred for achieving the objects of the invention.
• dope a solution wherein a cellulose ester, an epoxy compound, a polymerization accelerator, and the like are dissolved in a solvent
• a glucose unit constituting cellulose has three bindable hydroxyl groups.
• the degree of substitution with the acetyl groups is 3.0.
• the degree of acyl substitution can be measured in accordance .with ASTM-D817-96.
• the starting cellulose of the cellulose ester for use in the invention is not particularly limited and there may be mentioned cotton linter, wood pulp, kanaf, and the like. Moreover, the cellulose derivatives obtained therefrom can be used solely or as a mixture thereo.f in any ratio but it is preferably to use cotton linter in an amount of 50% by mass or more.
• the molecular weight of the cellulose ester is preferably from 70,000 to 200,000, more preferably from 100,000 to 200,000 as number average molecular weight (Mn) .
• Mn number average molecular weight
• the Mw/Mn ratio of the cellulose ester for use in the invention is less than 3.0, preferably from 1.4 to 2.3.
• the average molecular weight and the molecular weight distribution of the cellulose ester can be measured using a high performance liquid chromatography, the number average molecular weight (Mn) and weight average molecular weight (Mw) can be measured using the same to calculate the ratio.
• the measuring conditions are as follows:
• Calibration curve a calibration curve with 13 samples of standard polystyrenes STK standard polystyrenes (manufactured by Tosoh Corporation) having Mw of 1,000,000 to 500 are used. The 13 samples are preferably used at even intervals.
• the cellulose ester film of the invention preferably contains a plasticizer, a UV absorber, an antioxidant, fine particles (mat agent) , a retardation regulator, and the like.
• the plasticizer is not particularly limited but a phosphate ester-based plasticizer, a phthalate ester- based plasticizer, a trimellitate ester-based plasticizer, a pyromellitate ester-based plasticizer, a glycolate-type plasticizer, a citrate ester-based plasticizer, a polyester-based plasticizer, or the like is preferably used.
• triphenyl phosphate tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, or tributyl phosphate
• diethyl phthalate dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, _ dibutyl phthalate, di-2-ethylhexyl phthalate, dicyclohexyl phthalate, or butyl benzyl phthalate as the phthalate ester-type plasticizer
• tributyl trimellitate triphenyl trimellitate, or triethyl trimellitate as the trimellitate-based plasticizer
• tetrabutyl pyromellitate tetraphenyl pyromellitate
• tetraphenyl pyromellitate or tetraphenyl trimell
• carboxylate esters examples include butyl oleate, methyl acetyllicinolate, dibutyl sebacate, and dicyclohexyl phthalate.
• polyester-based plasticizer a copolymer of a dibasic acid such as an aliphatic dibasic acid, an alicyclic dibasic acid, or an aromatic dibasic acid with a glycol
• the aliphatic dibasic acid is not particularly limited and adipic acid, sebacic acid, phthalic acid, terephthalic acid, 1,4- cyclohexyldicarboxylic acid, or the like can be used.
• glycol ethylene glycol, diethylene glycol, 1,3-- propylene glycol, 1, 2-propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, or the like can be employed. These dibasic acid and glycols may be used solely or as a mixture of two or more thereof, respectively.
• the amount of these plasticizers to be used is preferably from 1 to 20% by mass based on the cellulose ester in view of film performance, processing ability, and the like.
• the UV absorber one exhibiting an excellent absorbing ability of a ultraviolet ray having a wavelength of 370. nm or shorter and a small absorbance of a visible light having a wavelength of 400 nm or longer is preferably used from the viewpoint of good liquid- crystal displaying ability.
• the UV absorber to be preferably used there may be mentioned oxybenzophenone-bas'ed compounds, benzotriazole-based compounds, triazine-based compounds, salicylate ester- based compounds, benzophenone-based compounds, cyanoacrylate-based compounds, nickel complex salt-based compounds, and the like but the UV absorber is not limited thereto.
• polymer UV absorbers described in JP-A-6-148430 are also preferably employed.
• UV absorber As specific examples of the UV absorber to be useful in the invention, there may be mentioned 2- (2 ' -hydroxys' -methylphenyl)benzotriazole, 2- (2 '-hydroxy-3 ' , 5_' -di- tert-b ⁇ tylphenyl) benzotriazole, 2- (2 ' -hydroxy-3 ' -tert- butyl-5 ' -methylphenyl) benzotriazole, 2- (2 ' -hydroxy-3 ' , 5 ' - di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2 ' - hydroxy-3'- (3", 4", 5" 6"-tetrahydrophthalimidomethyl) -5'- methylphenyl) benzotriazole, 2, 2-methylenebis (4- (1, 1, 3, 3- tetramethylbutyl) -6- (2H-benzotriazol-2-yl)phenol) , 2- (2'- hydroxy-3
• benzophenone-based compound there may be mentioned 2,4- dihydroxybenzophenone, 2,2' -dihydroxy-4- methoxybenzophenone, 2-hydroxy-4-methoxy-5- sulfobenzophenone, bis (2-methoxy-4-hydroxy-5- benzoylphenylmethane) , and the like but it is not particularly limited thereto.
• UVT-I UVT-I
• the cellulose ester film in the invention preferably contains particles serving as a mat agent.
• the particles for use herein include silicon dioxide, titanium dioxide, aluminium oxide, zirconium oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, calcium silicate hydrate, aluminium silicate, magnesium silicate and calcium phosphate.
• the particles are preferably silicon-having ones as the haze of the films containing them may be low.
• silicon dioxide Particles of silicon dioxide for use herein preferably have a primary mean particle size of at most 20 nm and have an apparent specific gravity of at least 70 g/liter.
• particles having a small primary mean particle size of from 5 to 16 nm since the haze of the films containing them is lower.
• the apparent specific gravity is more preferably from 90 to 200 g/liter, even more preferably from 100 to 200 g/liter. Particles having a larger apparent specific gravity may give a dispersion having a higher concentration, and are therefore preferable since the haze of the films containing them could be lower and since the solid deposits in the film may . . be reduced.
• the particles generally form secondary particles having a mean particle size of from 0.1 to 3.0 ⁇ m, and in the film, they exist as aggregates of primary particles, therefore forming protrusions having a size of from 0.1 to 3.0 ⁇ m in the film surface.
• the secondary mean particle size is from 0.2 ⁇ m to 1.5 ⁇ m, more preferably from 0.4 ⁇ m to 1.2 ⁇ m, most preferably from 0.6 ⁇ m to 1.1 ⁇ m.
• the primary and secondary particle sizes are determined as follows: The particles in a film are observed with a scanning electromicroscope, and the diameter of the circle that is circumscribed around the particle is referred to as the particle size. 200 particles are observed at random in different sites, and their data are averaged to give the mean particle size thereof.
• silicon dioxide particles herein usable are commercial products of Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (all by Nippon Aerosil) .
• Zirconium oxide particles are also commercially available, for example, as Aerosil R976 and R811 (both by Nippon Aerosil) , and are usable herein.
• Aerosil 200V and Aerosil R972V are silicon dioxide particles having a primary mean particle size of at most 20 nm and having an apparent specific gravity of at least 70 g/liter, and these are especially preferred for use herein since they are effective for reducing the friction coefficient of cellulose ester films not increasing the haze thereof.
• a dispersion of particles for obtaining a cellulose ester film that contains particles having a small secondary mean particle size, there may be employed some methods for preparing a dispersion of particles.
• one method for it comprises previously preparing a dispersion of particles by stirring and mixing a solvent and particles, then adding the resulting dispersion to a small amount of a cellulose ester solution separately prepared, and thereafter further mixing it with a main dope. This method is desirable since the dispersibility of silicon dioxide particles is good and since the dispersion of silicon dioxide particles prepared hardly reaggregates .
• the silicon dioxide concentration in the resulting dispersion is preferably from 5 to 30 % by mass, more preferably from 10 to 25 % by mass, most preferably from 15 to 20 % by mass.
• the dispersion having a higher concentration may have a smaller haze, and is therefore favorable since the haze of the films with it may be lowered and the solid deposits may be reduced in the films.
• the amount of the mat agent to be in the dope is preferably from 0.01 to 1.0 g/m 2 , more preferably from 0.03 to 0.3 g/m 2 , most preferably from 0.08 to 0.16 g/m 2 .
• the cellulose ester film of the invention may contain a retardation regulator.
• the cellulose ester film of the invention can exhibit preferred retardation only after adding a compound increasing retardation (retardation-increasing agent) and stretching the film, and thereby the film can be used as a retardation film.
• a compound having a rod-shaped structure or a planer structure is preferably used.
• a cellulose ester film having a small optical anisotropy can be obtained by incorporating a compound inhibiting orientation of the cellulose ester in the film in the in-plane and film-thickness directions (retardation-decreasing agent) , and the film can be preferably used as a support of a protective film for a polarizing plate or an optically-compensatory film.
• the compound decreasing optical anisotropy is sufficiently compatible to the cellulose ester and the compound itself does not have a rod-shaped structure or a planar structure.
• a structure having the functional groups not in the same plane but in non-planar manner is advantageous .
• the cellulose ester film it is preferred to produce the cellulose ester film by a solution casting method and the film is produced using a dope.
• a solvent selected from esters, ketones, and ethers having 3 to 12 carbon atoms and halogenated hydrocarbons having 1 to 7 carbon atoms is preferred.
• the esters, ketones, and ethers may have a cyclic structure.
• a compound having two or more functional groups selected from ester, ketone, and ether groups, i.e., -0-, -CO- and -COO- can be also used as the main solvent and the compound may also have other functional group such as an alcoholic hydroxyl group.
• the solvent to be used in the dope solution of the invention may contain a chlorine-based halogenated hydrocarbon as the main solvent and may contain a non- chlorine-based solvent as the main solvent as described in Hatsumei Kyokai's Disclosure Bulletin 2001-1745, pp. 12-16, and the solvent is not particularly limited.
• solvents for the cellulose ester film of the invention are disclosed in the following patent publications including methods for dissolving the same, which are preferred' embodiments. For example, they are described in JP-A 2000-95876, 12-95877, 10-324774, 8- 152514, 10-330538, 9-95538, 9-95557, 10-235664, 12-63534, 11-21379, 10-182853, 10-278056, 10-279702, 10-323853, 10- 237186, 11-60807, 11-152342, 11-292988, and 11-60752.
• solvents preferable for the dopes but also physical properties thereof and co-existing substances to be co- present, which are also preferred embodiments in the invention.
• the preparation of the dope is not particularly limited and may be carried out at room temperature or is carried out by a cool dissolving method or a high-temperature dissolving method or a combination thereof.
• the production steps detailed in Hatsumei Kyokai's Disclosure Bulletin 2001-1745 (issued March 15, 2001, by Hatsumei Kyokai) , pp. 22-25 are preferably employed.
• a process of forming a film from the cellulose ester solution in the invention is described.
• the equipment for producing the cellulose ester film in the invention herein employable are the solvent-casting method and the solvent-casting equipment heretofore generally used in the art for cellulose triacetate film formation.
• a dope prepared in a dissolver (tank) is once stored in a storage tank, in which the dope is defoamed and is thus finally prepared.
• the dope is taken out and fed into a pressure die via a metering pressure gear pump capable of feeding it with accuracy, for example, based on the revolution number thereof, and then the dope is uniformly cast onto the endlessly- running cast member of a metal support via the slit of the pr.essure die, and at a peel point to which the metal support makes nearly one revolution, the still wet dope film (this may be referred to as a web) is peeled from the metal support.
• the web is conveyed with a tenter and dried, and then further conveyed with rolls in a drier in which the web is completely dried, and thereafter this is wound up around a winder to predetermined width.
• the combination of the tenter and the drier with rolls may vary depending on the object of the film to be produced.
• additional coating devices may be fitted to the solvent casting apparatus for producing the film. The additional devices are for further processing the surface of the film by forming thereon a subbing layer, an antistatic layer, an antihalation layer and a protective layer.
• the thickness of the cellulose ester .film is preferably from 10 to 120 ⁇ m, more preferably from 20 to 100 ⁇ m, even more preferably 30 to 95 ⁇ m.
• the epoxy compound is polymerized (or crosslinked) simultaneously with drying by heating in the above drying step.
• the heating temperature and heating time vary depending on the epoxy compound or polymerization accelerator to be used. In general, the temperature is preferably 70°C or higher, for example, from 70°C to 170°C, more preferably from 80°C to 160°C, most preferably 9O 0 C to 150°C.
• The' drying (heating) time is preferably from 20 minutes to 240 minutes, most preferably from 30 minutes to 180 minutes.
• the water vapor permeability of the cellulose ester film is desirably from 200 to 1800 g/m 2 -24 hr in terms of a film thickness of 80 ⁇ m in the measurement under conditions of a temperature of 60°C and a humidity of 95%RH in accordance with JIS standard JIS Z0208. More preferred is from 300 to 1500 g/m 2 -24 hr and particularly preferred is from 400 to 1200 g/m 2> 24 hr . When it exceeds 1800 g/m 2 '24 hr, an absolute values of humidity dependence of an in-plane retardation Re and a retardation Rth in the thickness direction strongly tend to exceed 0.5 nm/%RH.
• the water vapor permeability of the cellulose ester film is less than 200 g/m 2 -24 hr, drying of an adhesive is inhibited by the cellulose ester film and an insufficient adhesion occurs in the case that the film is attached to both faces of a polarizer to prepare a polarizing plate.
• the water vapor permeability decreases when the thickness of the cellulose ester film of the invention is large and the water' vapor permeability increases when the film thickness is small. Therefore, it is necessary to convert the water vapor permeability with standardizing the film thickness to 80 ⁇ m in every sample having any film thickness.
• the elastic modulus of the cellulose ester film of the invention is preferably from 200 to 500 kgf/mm 2 (1.96 to 4.9 GPa), more preferably from 240 to 470 kgf/mm 2 (2.35 to 4.61 GPa), even more preferably from 270 to 440 kgf/mm 2 (2.65 to 4.31 GPa).
• stress at 0.5% elongation is measured at a tensile rate of 10%/minute under an atmosphere of 23°C and 70%RH using a universal tensile tester STM T50BP manufactured by Toyo Baldwin to determine the elastic modulus .
• ⁇ Use of cellulose ester film> [Optically-Compensatory Film]
• the cellulose ester film of the invention has many applications. When it is used for an optically- compensatory film in liquid-crystal display devices, it is especially effective.
• An optically-compensatory film is generally used in liquid-crystal display devices, and this is an optical member for compensating retardation.
• the optically-compensatory film has the same meaning as that _ of a phase retarder and an optically-compensatory sheet.
• the optically-compensatory film has a property of birefringence, and it is used for the purpose of removing coloration of display panels of liquid-crystal display devices and for improving the viewing angle characteristics of the devices.
• the film in the case that retardation is expressed, the film itself can be preferably used as an optically-compensatory film. Moreover, in the other cases, the film can be preferably used as a support for an optically-anisotropic layer.
• Re 6 3o is from 0 to 200 nm and
• Rth S30 1 is from 0 to 400 nm and an optically-anisotropic layer of any type may be used as far as it has such ranges of the values.
• the cellulose ester film of the invention may be combined with an optically-anisotropic layer of any type required in optically-compensatory films, not limited by the optical properties and the driving system of the liquid-crystal cell in the liquid- crystal display device in which the film is to be used.
• the optically-anisotropic layer to be combined with the film may be formed of a composition containing a liquid- crystal compound, or may be formed of a polymer film having a property of birefringence.
• an optically-anisotropic layer containing a liquid-crystal compound is used as an optically-anisotropic layer
• a discotic liquid-crystal compound or a rod-shaped liquid-crystal compound is preferred as the liquid-crystal compound.
• the discotic liquid-crystal molecules are fixed as aligned in the optically-anisotropiq layer in the invention, most preferably fixed therein through polymerization.
• the polymerization of discotic liquid- crystal molecules is described in JP-A 8-27284.
• a polymerizable group must be bonded to the disc core of each discotic liquid-crystal molecule as a substituent thereto.
• a linking group is introduced between the disc core and the polymerizable group to be bonded thereto.
• Such polymerizable group- having discotic liguid-crystal molecules are disclosed in JP-A 2001-4387. (Rod-Shaped Liquid-Crystal Compound)
• rod-shaped liquid-crystal compound usable in the invention examples include azomethines, azoxy compounds, cyanobiphenyls, cyanophenyl esters, benzoates, phenyl cyclohexanecarboxylates, cyanophenylcyclohexanes, cyano- substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolans, and alkenylcyclohexylbenzonitriles . Not only such low- molecular liquid-crystal compounds, but also high- molecular liquid-crystal compounds may also be usable herein.
• the rod-shaped liquid-crystal molecules are fixed in an aligned state, most preferably they are fixed through polymerization.
• Examples of the polymerizable rod-shaped liquid-crystal compound usable in the invention are described in Macromol. Chem. , Vol. 190, p. 2255 (1989); Advanced Materials, Vol. 5, p. 107 (1993); US Patents
• the optically-anisotropic layer may be formed of a polymer film.
• the polymer film is formed from a polymer capable of expressing optical anisotropy.
• the polymer are polyolefin (e.g., polyethylene, polypropylene, norbornene-based polymer) , polycarbonate, polyarylate, polysulfone, polyvinyl alcohol, polymethacrylate, polyacrylate and cellulose ester (e.g., cellulose triacetate, cellulose diacetate) . Copolymers or mixtures of these polymers may also be usable herein.
• the optical anisotropy of the polymer film is preferably generated by stretching.
• the stretching is preferably monoaxial stretching or biaxial stretching.
• machine-direction monoaxial stretching to be attained by utilizing the peripheral speed difference between two or more rolls; or tenter stretching to be attained by clipping both sides of a polymer film and stretching it in the width direction; or biaxial stretching comprising a combination of these.
• two or more polymer films may be used so that the overall optical properties of these two or more films may satisfy the above-mentioned conditions.
• the polymer film is produced according to a solvent casting method in order that the birefringence unevenness of the film is reduced as much as possible.
• the thickness of the polymer film falls between 20 and
• a method of stretching the polymer film and the substrate to express an optical anisotropy and using the film as an optically-anisotropic layer is also preferably employed.
• the cellulose ester film of the invention can be preferably used as a substrate in this case.
• the polymer film is separately prepared on another substrate and the polymer film after peeled from the substrate is attached onto the cellulose ester film of the invention to use the combined one as an optically-anisotropic layer.
• the thickness of the polymer film can be made small and is preferably from 50 ⁇ m or less, more preferably from 1 to 20 ⁇ m.
• the cellulose ester film of the invention is useful especially for a protective film for a polarizing plate.
• a method for manufacturing the polarizing plate is not particularly limited and can be manufactured by a common method. There is a method of subjecting the cellulose ester film obtained to alkaline treatment and attaching it onto both faces of a polarizer which has been prepared by immersing and stretching a polyvinyl alcohol film in an iodine solution and stretching the same using a completely saponified polyvinyl alcohol aqueous solution.
• a processing for easy adhesion as described in JP-A 6-94915 and 6-118232 may be applied instead of the alkaline- treatment.
• the adhesive to be used for attaching the treated surface of the protective film to the polarizer there may be, for example, mentioned polyvinyl alcohol-based adhesives such as polyvinyl alcohol and polyvinyl butyral and vinyl-based latexes such as butyl acrylate.
• a polarizing plate is constituted by a polarizer and protective films protecting both faces thereof and further constituted by attaching a protect film on one face of the polarizing plate and a • separate film on the other face.
• the protect film and the separate film are used for the purpose of protecting the polarizing plate at shipping of the polarizing plate and at product inspection.
• the protect film is attached for the purpose of 'protecting the surface of the polarizing plate and is used at the opposite face of the surface of the polarizing plate to be adhered to a liquid crystal cell.
• the separate film is used for the purpose of covering the adhesive layer to be attached to the liquid-crystal cell and is used at the face of the polarizing plate to be attached to the liquid-crystal cell.
• a substrate containing a liquid crystal is usually arranged between two polarizing plates.
• the protective film for the polarizing plate to which the cellulose ester film of the invention is applied may be arranged at any site.
• a clear hard coat layer, an antiglare layer, an antireflection layer, and the like are generally fitted to the protective film for the polarizing plate which is arranged at the top surface at the displaying side of the liquid-crystal display device. Even in that case, the protective film for the polarizing plate can be used at that part.
• the difference between the transmittance of a light entering in the normal direction (in-plane transmittance) and the transmittance of a light entering at a tilt angle of 50° in the direction of 45° toward the absorption axis (transmittance in 50°-tilt direction) is preferably 1.0 or less.
• the difference of the transmittance is 1.0 or less, a liquid-crystal display device having a good performance of the polarizing plate and a good property of viewing angle can be provided.
• the difference of the transmittance can be determined by attaching two sheets of the polarizing plate to both faces of the glass substrate so that the absorption axes of the sheets are positioned orthogonal each other and then measuring a light entering at a tilt angle of polar angle 50°, when the absorption axis is regarded as an azimuthal 'angle of 0° and the normal line of the substrate is regarded as a polar angle of 0° in the direction of 45° thereof, and a light entering in the normal direction using a known measuring equipment such as a transmittance-measuring equipment "MCPD3000" (manufactured by Otsuka Denshi K. K.) .
• MCPD3000 transmittance-measuring equipment
• the reason why the direction of 45° is used toward the absorption axis is that the difference of the transmittance is larger in the case that a light enters at a tilt angle of 50° in the direction of 45° toward the absorption axis than the difference of the transmittance in the case that a light enters at a tilt angle of 50° in the same direction as that of the absorption axis.
• the difference of the transmittance in the latter case is 1.0 or less, a good polarizing performance is obtained as described above.
• the cellulose ester film of the invention is suitably used as a protective film for the polarizing plate.
• the liquid-crystal display device has a constitution wherein a liquid-crystal cell supporting liquid crystals between two electrode substrates and two polarizing plates arranged at both faces thereof are arranged and suitably at least one optically-compensatory film is arranged between the liquid-crystal cell and the polarizing plate.
• the cellulose ester film of the invention in the above constitution of the liquid crystal display device, the cellulose ester film may be used as at least one optically-compensatory film arranged between the liquid-crystal cell and the polarizing plate without changing the constitution or may be used as an integrated one after the side to which a liquid-crystal layer or a polymer layer as an optically-anisotropic layer is not fitted is directly attached to the polarizing plate to form an optically-compensatory and polarizing plate- protective film.
• the transmission axis of the polarizing film and the retardation axis of the optically-compensatory film can be arranged at any angle.
• the liquid-crystal layer of the liquid-crystal cell is generally formed by introducing a liquid crystal into the space formed by two substrates via a spacer put therebetween, and sealed up in it.
• a transparent electrode layer is formed on a substrate as a transparent film that contains a conductive substance.
• the liquid- crystal cell may further have a gas barrier layer, a hard coat layer or an undercoat layer (for adhesion to transparent electrode layer) . These layers are generally formed on a substrate.
• the substrate of the liquid- crystal cell generally has a thickness of from 50 ⁇ m to 2 mm.
• the cellulose ester film of the invention may be used for liquid-crystal cells of various display modes.
• Various display modes such as TN (twisted nematic) , IPS
• the cellulose ester film of the invention is effective in liquid-crystal display devices of any display mode. Further, it is also effective in any of transmission-type, reflection-type and semitransmission-type liquid-crystal display devices.
• the cellulose ester film of the invention may be used as a support of the optically-compensatory film or a protective film for the polarizing plate in TN-mode liquid-crystal cell-having TN-mode liquid-crystal display devices .
• TN-mode liquid-crystal cells and TN-mode liquid-crystal display devices are well known from the past.
• the optically-compensatory film to be ' used in TN- mode liquid-crystal display devices is described in JP-A 3-9325, 6-148429, 8-50206, 9-26572. In addition, it is also described in Mori et al ' s reports ⁇ Jpn. J. Appl . Phys., Vol. 36 (1997), p. 1068). (STN-Mode Liquid-Crystal Display Device)
• the cellulose ester film of the invention may be used as a support of the optically-compensatory film or a protective film for the polarizing plate in STN-mode liquid-crystal cell-having STN-mode liquid-crystal display devices.
• the rod-shaped liquid- crystal molecules in the liquid-crystal cell in an STN- mode liquid-crystal display device are twisted at an angle within a range of from 90 to 360 degrees, and the product of the refractivity anisotropy ( ⁇ n) of the rod- shaped, liquid-crystal molecules and the cell gap (d) , ⁇ nd falls between 300 and 1500 nm.
• the optically- compensatory film to be used in STN-mode liquid-crystal display devices is described in JP-A 2000-105316. (VA-Mode Liquid-Crystal Display Device)
• the cellulose ester film of the invention is especially favorable for a support of the optically- compensatory film or a protective film for the polarizing plate in VA-mode liquid-crystal cell-having VA-mode liquid-crystal display devices.
• the optically-compensatory film for use- in VA-mode liquid- crystal display devices has a retardation Re of from 0 to 150 nm and a retardation Rth of from 70 to 400 nm. More preferably, the retardation Re of the sheet is from 20 to 70 nm.
• the retardation Rth of the films preferably falls between 70 and 250 nm.
• the retardation Rth of the film preferably falls between 150 and 400 nm.
• the VA-mode liquid-crystal display devices for the invention may have an orientation-divided system, for example, as in JP-A 10-123576. (IPS-Mode Liquid-Crystal Display Device and ECB-Mode Liquid-Crystal Display Device)
• the cellulose ester film of the invention is also favorable for a support of the optically-compensatory film or a protective film for the polarizing plate in IPS-mode and ECB-mode liquid-crystal cell-having liquid- crystal display devices.
• These modes are embodiments wherein liquid crystal materials are aligned in almost parallel when black is displayed and black is displayed by aligning liquid-crystal molecules in parallel in a state where voltage is not applied.
• an optically-anisotropic layer is arranged between the protective film for the polarizing plate and the liquid- crystal cell and the retardation of the arranged optically-anisotropic layer is set at a value twice or less the value of ⁇ n-d of the liquid-crystal layer.
• the cellulose ester film of the invention is also favorable for a support of the optically-compensatory film or a protective film for the polarizing plate in OCB-mode liquid-crystal cell-having OCB-mode liquid- crystal display devices and HAN-mode liquid-crystal cell- having HAN-mode liquid-crystal display devices.
• the optically-compensatory film for use in OCB-mode liquid-crystal display devices and HAN-mode liquid-crystal display devices is so designed that the direction in which the absolute value of the retardation of the film is the smallest does not exist both in the in-plane direction and in the normal line direction of the optically-compensatory film.
• optical properties of the optically-compensatory film for use in OCB-mode liquid-crystal display devices and HAN-mode liquid- crystal display devices are determined, depending on the optical properties of the optically-anisotropic layer, the optical properties of the support and the positional relationship between the optically-anisotropic layer and the support.
• the optically-compensatory film for use in OCB-mode liquid-crystal display devices and HAN-mode liquid-crystal display devices is described in JP-A 9- 197397. It is described also in Mori et al ' s reports ⁇ Jpn. J. Appl. Phys., Vol. 38 (1999), p. 2837). (Reflection-Type Liquid-Crystal Display Device)
• the cellulose ester film of the invention is also favorably used for an optically-compensatory film or a protective film for the polarizing plate in TN-mode, STN- mode, HAN-mode or GH (guest-host) -mode reflection-type liquid-crystal display devices.
• TN-mode reflection-type liquid-crystal devices are described in JP-A 10-123478, pamphlet of International Laid-Open No. 98/48320, and Japanese Patent 3022477.
• the optically-compensatory film for use in reflection-type liquid-crystal display devices is described in pamphlet of International Laid-Open No. 00/65384. (Other Liquid-Crystal Display Devices)
• the cellulose ester film of the invention is also favorably used as a support of the optical .
• compensatory film or a protective film for the polarizing plate in ASM (axially symmetric aligned microcell) -mode liquid-crystal cell-having ASM-mode liquid-crystal display devices The liquid-crystal cell in ASM-mode devices is characterized in that it is supported by a resin spacer capable of controlling and varying the thickness of the cell. The other properties of the cell are the same as those of the liquid-crystal cell in TN-mode devices.
• ASM-mode liquid- crystal cells and ASM-mode liquid-crystal display devices are described in Kume et al's report (Kume et al . , SJD 98 Digest 1089 (1998) ) . (Hard Coat Film, Antiglare Film, Antireflection Film)
• the cellulose ester film of the invention is favorably applied to hard coat films, antiglare films and antireflection films.
• hard coat films for the purpose of improving the visibility of flat panel displays such as LCD, PDP, CRT, EL, any or all of a hard coat layer, an antiglare layer and an antireflection layer may be fitted to one or both faces of the cellulose ester film of the invention.
• Preferred embodiments of such antiglare films and antireflection films are described in Hatsumei Kyokai's Disclosure Bulletin 2001-1745 (issued March 15, 2001, by Hatsumei Kyokai), pp. 54-57, and the cellulose ester film of the invention may be favorably used in these.
• these functional polarizing plate can be formed by fitting at least any of a hard coat layer, an antiglare layer, and an antireflection layer to the surface of the above polarizing plate and the resulting functional polarizing plate can be suitably used in liquid-crystal display devices.
• the cellulose ester film usable in the invention is applicable to supports of silver halide photographic materials. Various materials and formulations and methods for processing them are described in some patent publications, and they may apply to the invention. Regarding the techniques, JP-A 2000-105445 has detailed descriptions of color negative films, and the cellulose ester film of the invention is favorably used in these. Also preferably, the film of the invention is applicable to supports of color reversal silver halide photographic materials, and various materials and formulations and methods for processing them described in JP-A 11-282119 are applicable to the invention. (Transparent Substrate)
• the cellulose ester film of the invention since the cellulose ester film of the invention has nearly zero optical anisotropy and has good transparency, it may be substitutable for the glass substrate for liquid-crystal cells in liquid-crystal display devices, or that is, it may be usable as a transparent support for sealing up the driving liquid crystals in the devices.
• a gas-barrier layer may be optionally fitted to the surface of the cellulose ester film of the invention, if desired.
• the morphology and the material of the gas-barrier layer are not specifically defined.
• Si ⁇ 2 may be deposited on at least one face of the cellulose ester film of the invention, or a polymer coating layer of a vinylidene-based polymer or a vinyl alcohol-based polymer having a relatively higher gas-barrier property may be formed on the film of the invention.
• a transparent electrode When the film of the invention is used as a transparent substrate for sealing up liquid crystal, a transparent electrode may be fitted to it for driving liquid crystal through voltage application thereto.
• the transparent electrode is not specifically defined.
• a metal film or a metal oxide film may be laminated on at least one surface of the cellulose ester film of the invention so as to form a transparent electrode on it.
• a meal oxide film is preferred in view of the transparency, the electroconductivity and the mechanical characteristics of the film; and a thin film of indium oxide essentially comprising tin oxide and containing from 2 to 15 % of zinc oxide is more preferred.
• composition of Cellulose Acetate Solution A Cellulose acetate having a degree of acetyl substitution of 2.92 100.0 parts by mass
• Triphenyl phosphate 8.0 parts by mass
• composition of Mat Agent Solution The following composition was charged into a dispersing machine and stirred to dissolve individual components, whereby mat agent solution was prepared.
• the following composition was charged into a mixing tank and stirred under heating, whereby a polymerization accelerator solution was prepared.
• Samples A-2 to A-17 were manufactured in the same manner except that the type and addition amount of the epoxy compound and polymerization accelerator were changed to the contents of Table 1, i.e., the type and concentration of the epoxy solution and polymerization accelerator solution were changed.
• samples B-2 and B-Il corresponding to the samples A-2 and A-Il were manufactured similarly except that a polymer CAP (degree of substitution with acetyl group: 1.9, degree of substitution with propionyl ' group: 0.8) wherein part of cellulose acetate was changed to cellulose propionate is used instead of cellulose acetate.
• a polymer CAP degree of substitution with acetyl group: 1.9, degree of substitution with propionyl ' group: 0.8
• samples C-2 and C-Il corresponding to the samples A-2 and A-Il were manufactured similarly except that a polymer CAB (degree of substitution with acetyl group: 1.1, degree of substitution with butyryl group: 1.6) wherein part of cellulose acetate was changed to cellulose butyrate is used instead of cellulose acetate.
• samples D-2 and D-Il corresponding to the samples A-2 and A-Il were manufactured similarly except that triphenyl phosphate in the composition of the above cellulose acetate solution A was replaced by a retardation-decreasing agent X.
• samples E-2 and E-Il corresponding to the samples A-2 and A-Il were manufactured similarly except that triphenyl phosphate in the composition of the above cellulose acetate solution A was replaced by a retardation-increasing agent Y.
• the water vapor permeability of each sample was measured.
• the method described in "Kobunshi no Bussei II" 'Kobunshi Jikken Koza 4, Kyoritsu Shuppan) , pp. 285- 294: Joki Tokaryo no Sokutei (Shitsuryo-hou, " Ondokei-hou, Jokiatsu-hou, Kyuchaku-hou) was applied.
• Example 1 The sample A-I of the invention obtained in Example 1 was immersed in a 1.5N sodium hydroxide aqueous solution at 55 0 C for 2 minutes. The sample was washed in a washing water bath at room temperature and then neutralized with 0. IN sulfuric acid at 3O 0 C. The sample was again washed in a washing water bath at room temperature and further dried at 100°C.
• the surface of the sample A-I was saponified.
• a roll-shaped polyvinyl alcohol film having a thickness of 80 ⁇ m was continuously stretched five times in an aqueous iodine solution and then dried to obtain a polarizer.
• a 3% aqueous solution of polyvinyl alcohol (PVA-117H manufactured by Kuraray Co., Ltd. ) as an adhesive two sheet of the sample A-I subjected to alkali saponification were attached via the polarizer put therebetween to obtain a polarizing plate P-I, two faces of which were protected by the sample A-I.
• the polarizing plates P-I to P-25 were allowed to stand under high-temperature and high-humidity conditions of 65°C and 95%RH for 14 days and change in polarization degree before and after the treatment was determined.
• the transmittance in the case that two sheets of the polarizing plate to be measured were overlaid each other so that the orientation directions of the polarizers thereof were identical with each other was referred to as parallel transmittance Tp.
• the transmittance in the case that two sheets of the polarizing plate were overlaid each other so that the orientation directions of the polarizers thereof were orthogonal each other was referred to as orthogonal transmittance Tc.
• a polarization degree P was calculated according to the following equation.
• a cellulose ester film which is (1) less apt to cause deterioration of planarity, (2) less apt to absorb moisture, (3) low in water vapor permeability and excellent in storability, and (4) capable of reuse since formation of three-dimensionally crosslinked cellulose ester can be minimized.
• the cellulose ester film of the invention can be produced by casting a solution containing various components and heating it, it is not necessary to use a large-scale equipment which is necessary at photo-polymerization and hence the film is (5) excellent in productivity.
• the above oligomer is used as the epoxy compound, generation of pollution during production steps is suppressed since there is no problem of toxicity and volatility.
• a polarizing plate and a liquid-crystal display device constituted using the cellulose ester film.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• General Physics & Mathematics (AREA)
• Materials Engineering (AREA)
• General Chemical & Material Sciences (AREA)
• Polarising Elements (AREA)
• Liquid Crystal (AREA)
• Compositions Of Macromolecular Compounds (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=36927534

Family Applications (1)

Country Status (2)

Cited By (8)

Families Citing this family (1)

Citations (5)

Family Cites Families (9)

• 2005
  • 2005-02-25 JP JP2005051233A patent/JP4831980B2/ja not_active Expired - Fee Related
• 2006
  • 2006-02-24 WO PCT/JP2006/304037 patent/WO2006090911A1/en active Application Filing

Patent Citations (5)

Also Published As

Similar Documents

Legal Events