WO2011104855A1 - Film de retard et procédé de production du film de retard - Google Patents

Film de retard et procédé de production du film de retard Download PDF

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WO2011104855A1
WO2011104855A1 PCT/JP2010/053057 JP2010053057W WO2011104855A1 WO 2011104855 A1 WO2011104855 A1 WO 2011104855A1 JP 2010053057 W JP2010053057 W JP 2010053057W WO 2011104855 A1 WO2011104855 A1 WO 2011104855A1
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film
acid
retardation
retardation film
tear strength
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PCT/JP2010/053057
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English (en)
Japanese (ja)
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高木 隆裕
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コニカミノルタオプト株式会社
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Priority to PCT/JP2010/053057 priority Critical patent/WO2011104855A1/fr
Priority to JP2012501585A priority patent/JP5637207B2/ja
Publication of WO2011104855A1 publication Critical patent/WO2011104855A1/fr

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    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00Optical elements other than lenses
    • G02B5/30Polarising elements
    • G02B5/3083Birefringent or phase retarding elements
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08JWORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/18Manufacture of films or sheets
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08KUse of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00Use of inorganic substances as compounding ingredients
    • C08K3/34Silicon-containing compounds
    • C08K3/36Silica
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08KUse of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00Use of organic ingredients
    • C08K5/02Halogenated hydrocarbons
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08KUse of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00Use of organic ingredients
    • C08K5/04Oxygen-containing compounds
    • C08K5/05Alcohols; Metal alcoholates
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08KUse of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00Use of organic ingredients
    • C08K5/04Oxygen-containing compounds
    • C08K5/10Esters; Ether-esters
    • C08K5/101Esters; Ether-esters of monocarboxylic acids
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08KUse of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00Use of organic ingredients
    • C08K5/49Phosphorus-containing compounds
    • C08K5/51Phosphorus bound to oxygen
    • C08K5/53Phosphorus bound to oxygen bound to oxygen and to carbon only
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08JWORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2301/00Characterised by the use of cellulose, modified cellulose or cellulose derivatives
    • C08J2301/08Cellulose derivatives
    • C08J2301/10Esters of organic acids
    • C08J2301/12Cellulose acetate

Definitions

  • the present invention relates to a retardation film using a cellulose acetate film, a polarizing plate using the same, a liquid crystal display device, and a method for producing a cellulose acetate film, and particularly when used as a retardation film for a liquid crystal display device.
  • a retardation film capable of improving viewing angle characteristics by exhibiting a good optical compensation function, exhibiting excellent contrast, and being excellent in physical isotropy, a polarizing plate and a liquid crystal display using the same Relates to the device.
  • Liquid crystal display devices are widely used in monitors for personal computers and portable devices, and for television applications because of their various advantages such as low voltage and low power consumption, and enabling miniaturization and thinning.
  • liquid crystal display devices for television that are expected to be viewed from various angles on a large screen have severe demands for viewing angle dependency, and recently, the performance requirements for liquid crystal display devices for monitors are also increasing.
  • a liquid crystal display device is composed of a liquid crystal cell, a retardation film (also called a retardation plate) for improving viewing angle characteristics, and a polarizing plate.
  • the phase difference film is used to eliminate image coloring or enlarge the viewing angle.
  • a film provided with birefringence by stretching a resin film is attached to a polarizing plate, or isotropic.
  • a technique for providing birefringence as a retardation film by providing a protective film for polarizing plate with a liquid crystal layer in which liquid crystal molecules are aligned in an arbitrary direction is known.
  • Patent Document 1 discloses a technique in which a retardation film obtained by stretching a mixed fatty acid ester film of cellulose in the width direction is applied to a VA mode liquid crystal cell to widen the viewing angle.
  • Patent Document 2 there is described a retardation film in which a desired retardation value is given by adding a retardation increasing agent to cellulose triacetate.
  • the film is stretched at a high magnification in order to obtain a desired in-plane and depth retardation, or a cited document. It was necessary to add an additive such as a retardation increasing agent as in 2.
  • each polarizing plate is usually arranged so that the absorption axes of the polarizers are orthogonal to each other.
  • a retardation film is disposed on the liquid crystal cell side of each polarizing plate, but the two retardation films sandwiching the liquid crystal cell are so that the in-plane retardation directions are orthogonal to each other like the polarizer. Need to be placed in.
  • Patent Document 3 a technique has been proposed for making the physical properties in the MD direction and TD direction more equal under the retardation film processing condition atmosphere.
  • An object of the present invention is to provide a long retardation film that is physically stable under any environmental conditions during manufacturing and processing.
  • the object of the present invention was achieved by the following.
  • the in-plane retardation Ro represented by the following formula is 30 to 150 nm, and the ratio Rth / Ro between the thickness direction retardation Rth and the in-plane retardation Ro is greater than 0.8 and less than 5.
  • d the thickness (nm) of the retardation film
  • nx is the maximum refractive index in the plane of the film
  • ny is the refractive index in the direction perpendicular to the nx direction in the film plane
  • nz is the thickness. Represents the refractive index of the film in the direction.
  • the wavelength is 590 nm.
  • the tear strength in the film transport direction (MD direction) and the tear strength in the same width direction (TD direction) are both 30 mN or more and 120 mN or less at 60 ° C. and 10% RH. 2.
  • the retardation film as described in 1 above.
  • a cellulose acetate dope having an acetyl group substitution degree of 2.1 or more and 2.6 or less is prepared, the dope is cast on a metal support, the casting film is peeled off as a film from the support, and the peeled film
  • a method for producing a retardation film wherein a drying temperature is in a range of 140 ° C. to 200 ° C. in a gripping section, and a tension applied in a film width direction is 30 N / m or more and less than 100 N / m.
  • a specific additive is contained in cellulose acetate having an acetyl group substitution degree of 2.1 or more and 2.6 or less, and production conditions within a predetermined range are used.
  • the in-plane retardation Ro is 30 to 150 nm, and the ratio Rth / Ro between the thickness direction retardation Rth and the in-plane retardation Ro is greater than 0.8 and more than 5. It has been found that a small retardation film can be produced without greatly different physical properties in the long direction and the width direction.
  • the ratio of tear strength in the longitudinal direction (also referred to as MD direction) to the width direction (also referred to as TD direction) (Tear strength in MD direction / TD direction) It was found that a retardation film having a tear strength of 0.8 to 1.2 can be obtained.
  • the in-plane retardation Ro represented by the following formula is 30 to 150 nm, and the ratio Rth / Ro between the thickness direction retardation Rth and the in-plane direction retardation Ro is as follows.
  • ⁇ Tear strength> A normal retardation film is subjected to a stretching process in the production process for adjusting the retardation, which causes a difference in physical properties between the MD direction and the TD direction.
  • retardation is achieved.
  • the physical properties in the MD direction and the TD direction can be made uniform during manufacturing and processing while expressing.
  • the ratio between the tear strength in the longitudinal direction (MD direction) and the tear strength in the same width direction (TD direction) under the conditions of 23 ° C. and 55% RH and 60 ° C. and 10% RH: (MD direction tear strength) / TD direction tear strength) is 0.8 to 1.2 in all cases.
  • the tear strength at 23 ° C. and 55% RH is 40 mN or more and 150 mN or less, preferably 50 mN or more and 130 mN or less. In 60 degreeC10% RH, it is 30 mN or more and 120 mN or less, Preferably it is 40 mN or more and 120 mN or less.
  • the tear strength can be measured with a light weight tear device manufactured by Toyo Seiki Co., Ltd. according to the elemendorf method JIS K 7128 / 2-1991.
  • Ro is preferably in the range of 40 nm to 100 nm. Is more preferably 40 nm or more and 80 nm or less, and particularly preferably 45 nm or more and 60 nm or less.
  • Rth is preferably in the range of 90 nm to 300 nm, more preferably 90 nm to 200 nm, and particularly preferably 100 nm to 130 nm.
  • the cellulose acetate of the present invention has a acetyl group substitution degree of 2.1 to 2.6.
  • the degree of acetyl group substitution is determined by the method prescribed in ASTM-D817-96.
  • the cellulose acetate ⁇ of the present invention preferably has a 6% viscosity of 70 to 250 mPa ⁇ s, more preferably 80 to 220 mPa ⁇ s.
  • 6% viscosity can be measured by the following method.
  • the 6% viscosity is measured with an Ostwald viscometer using a 95% acetone solution having a concentration of 6% by mass of cellulose acetate at 25 ° C. ⁇ 1 ° C.
  • 6% viscosity (mPa ⁇ s) flow time (s) ⁇ viscosity coefficient
  • the viscometer coefficient is obtained by measuring the flow time by the same operation as described above using a viscometer calibration standard solution.
  • Viscometer coefficient ⁇ standard solution absolute viscosity (mPa ⁇ s) ⁇ solution density (0.827 g / cm 3 ) ⁇ / ⁇ standard solution density (g / cm 3 ) ⁇ standard solution flow time (s) ⁇
  • the cellulose acetate of the present invention has a 6% viscosity lower than that of cellulose acetate ⁇ , and is preferably 40 to 80 mPa ⁇ s. Cellulose acetate can be further mixed.
  • the cellulose acetate of the present invention can be produced by a conventional method such as a sulfuric acid catalyst method, an acetic acid method, or a methylene chloride method, and the raw material is preferably wood pulp.
  • Cellulose acetate is usually pulp (cellulose) activated with acetic acid or the like (activation step), and then triacetate is prepared with acetic anhydride using a sulfuric acid catalyst (acetylation step). It can be produced by adjusting the degree of acetylation by aging (saponification / aging process).
  • the activation step can be performed by treating pulp (cellulose), for example, by spraying acetic acid or hydrous acetic acid, immersing in acetic acid or hydrous acetic acid, etc.
  • the amount is about 10 to 100 parts by weight, preferably 20 to 80 parts by weight, and more preferably about 30 to 60 parts by weight with respect to 100 parts by weight of pulp (cellulose).
  • the amount of acetic anhydride used in the acetylation step can be selected within the range of the acetylation degree. For example, 230 to 300 parts by weight, preferably 240 to 290, per 100 parts by weight of pulp (cellulose). Part by mass, more preferably about 250 to 280 parts by mass.
  • acetic acid is usually used as a solvent.
  • the amount of acetic acid used is, for example, about 200 to 700 parts by weight, preferably 300 to 600 parts by weight, and more preferably about 350 to 500 parts by weight with respect to 100 parts by weight of pulp (cellulose).
  • sulfuric acid is usually used as the acetylation or aging catalyst.
  • the amount of sulfuric acid used is usually about 1 to 15 parts by mass, preferably about 5 to 15 parts by mass, and particularly about 5 to 10 parts by mass with respect to 100 parts by mass of cellulose.
  • the saponification / ripening can be performed at a temperature of about 50 to 70 ° C., for example.
  • the cellulose acetate produced may be treated with an oxidizing agent at an appropriate stage in the cellulose acetate production process, for example, after completion of acetylation, saponification or aging.
  • oxidizing agent examples include hydrogen peroxide; peracids such as performic acid, peracetic acid, and perbenzoic acid; and organic peroxides such as diacetyl peroxide.
  • the oxidizing agent can be used alone or in combination of two or more.
  • Preferred oxidizing agents include oxidizing agents that are easy to remove from cellulose acetate and have low persistence, such as hydrogen peroxide, performic acid, and peracetic acid, with hydrogen peroxide and peracetic acid being particularly preferred.
  • the amount of the oxidizing agent used can be selected according to the desired level of optical properties. For example, 0.01 to 5 parts by mass, preferably 0.1 to 2.5 parts by mass with respect to 100 parts by mass of cellulose acetate. In particular, it is about 0.1 to 1 part by mass.
  • the treatment with the oxidizing agent can be performed at, for example, about 20 to 100 ° C., preferably about 30 to 70 ° C., depending on the type of the oxidizing agent.
  • the cellulose acetate of the present invention is cellulose acetate L-30, L-40, L-50, L-70 (manufactured by Daicel Chemical Industries), Ca398-6, Ca398-10, Ca398-30, Ca394-60S (yeast Commercial products such as Man Chemical Japan Co., Ltd. can be used.
  • the retardation film of the present invention can be obtained by incorporating cellulose ester into the following sugar ester compound and polyester D represented by the general formula (1).
  • sugars preferably used in the present invention include the following, but the present invention is not limited to these.
  • Glucose galactose, mannose, fructose, xylose or arabinose, lactose, sucrose, nystose, 1F-fructosyl nystose, stachyose, maltitol, lactitol, lactulose, cellobiose, maltose, cellotriose, maltotriose, raffinose or kestose .
  • gentiobiose gentiotriose
  • gentiotetraose gentiotetraose
  • xylotriose galactosyl sucrose
  • sucrose examples include sucrose, kestose, nystose, 1F-fructosyl nystose, stachyose, and more preferably sucrose.
  • the monocarboxylic acid used for esterifying all or part of the OH groups in the pyranose structure or furanose structure of the present invention is not particularly limited, and known aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, An aromatic monocarboxylic acid or the like can be used.
  • the carboxylic acid used may be one type or a mixture of two or more types.
  • Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanecarboxylic acid, undecylic acid, lauric acid , Saturated fatty acids such as tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, and laccelic acid, Examples include unsaturated fatty acids such as undecylenic acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid and oc
  • Examples of preferable alicyclic monocarboxylic acids include acetic acid, cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid, and derivatives thereof.
  • aromatic monocarboxylic acids examples include aromatic monocarboxylic acids having an alkyl group or alkoxy group introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, cinnamic acid, benzylic acid, biphenylcarboxylic acid, and naphthalene.
  • aromatic monocarboxylic acids having two or more benzene rings such as carboxylic acid and tetralin carboxylic acid, or derivatives thereof.
  • Oligosaccharides are produced by allowing an enzyme such as amylase to act on starch, sucrose, etc.
  • examples of oligosaccharides that can be applied to the present invention include maltooligosaccharides, isomaltoligosaccharides, fructooligosaccharides, galactooligosaccharides, xylooligos. Sugar.
  • the sugar ester compound of the present invention is a compound obtained by condensing 1 or more and 12 or less of at least one pyranose structure or furanose structure represented by the following general formula (A).
  • R 11 to R 15 and R 21 to R 25 each represents an acyl group having 2 to 22 carbon atoms or a hydrogen atom, m and n each represents an integer of 0 to 12, and m + n represents an integer of 1 to 12.
  • R 11 to R 15 and R 21 to R 25 are preferably a benzoyl group or a hydrogen atom.
  • the benzoyl group may further have a substituent R 26 (p is 0 to 5), and examples thereof include an alkyl group, an alkenyl group, an alkoxyl group, and a phenyl group, and further, these alkyl groups, alkenyl groups, and phenyl groups. May have a substituent.
  • Oligosaccharides can also be produced by the same method as the ester compound of the present invention.
  • ester compound of the present invention is listed below, but the present invention is not limited thereto.
  • B- (GA) n-GB (Wherein B is an arylcarboxylic acid residue, G is an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol residue having 4 to 12 carbon atoms, A Represents an alkylene dicarboxylic acid residue having 4 to 12 carbon atoms or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms, and n represents an integer of 1 or more.)
  • arylcarboxylic acid component of the polyester D used in the present invention examples include benzoic acid, para-tert-butylbenzoic acid, orthotoluic acid, metatoluic acid, p-toluic acid, dimethylbenzoic acid, ethylbenzoic acid, normal propylbenzoic acid, There are aminobenzoic acid, acetoxybenzoic acid and the like, and these can be used as one kind or a mixture of two or more kinds, respectively.
  • alkylene glycol component having 2 to 12 carbon atoms of polyester D that can be preferably used in the retardation film used in the present invention
  • examples of the alkylene glycol component having 2 to 12 carbon atoms of polyester D that can be preferably used in the retardation film used in the present invention include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2- Butanediol, 1,3-butanediol, 1,2-propanediol, 2-methyl 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3 -Propanediol (neopentyl glycol), 2,2-diethyl-1,3-propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3propanediol (3,3 -Dimethylolheptane
  • alkylene glycols having 2 to 12 carbon atoms are particularly preferable because of excellent compatibility with cellulose esters.
  • Examples of the oxyalkylene glycol component having 4 to 12 carbon atoms of the aromatic terminal ester include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol. These glycols include 1 It can be used as a seed or a mixture of two or more.
  • alkylene dicarboxylic acid component having 4 to 12 carbon atoms of the aromatic terminal ester examples include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid. These are used as one kind or a mixture of two or more kinds.
  • arylene dicarboxylic acid component having 6 to 12 carbon atoms examples include phthalic acid, terephthalic acid, isophthalic acid, 1,5 naphthalene dicarboxylic acid, and 1,4 naphthalene dicarboxylic acid.
  • the polyester D used for the retardation film has a number average molecular weight of preferably 300 to 1500, more preferably 400 to 1000.
  • the acid value is 0.5 mgKOH / g or less, the hydroxyl value is 25 mgKOH / g or less, more preferably the acid value is 0.3 mgKOH / g or less, and the hydroxyl value is 15 mgKOH / g or less.
  • the retardation film of the present invention includes a phosphate ester plasticizer, a phthalate ester plasticizer, a trimellitic acid ester plasticizer, a pyromellitic acid plasticizer, a glycolate plasticizer, and a citrate ester plasticizer. Polyester plasticizers and phosphate ester plasticizer plasticizers can also be preferably used.
  • carboxylic acid esters examples include trimethylolpropane tribenzoate, butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters.
  • polyester plasticizer a copolymer of a dibasic acid and a glycol such as an aliphatic dibasic acid, an alicyclic dibasic acid, or an aromatic dibasic acid can be used.
  • the aliphatic dibasic acid is not particularly limited, and adipic acid, sebacic acid, phthalic acid, terephthalic acid, 1,4-cyclohexyl dicarboxylic acid and 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 and the like can be used.
  • dibasic acids and glycols may be used alone or in combination of two or more.
  • the amount of these plasticizers to be used is preferably 1% by mass to 20% by mass, particularly preferably 3% by mass to 13% by mass with respect to the cellulose ester in terms of film performance, processability and the like.
  • Such a cellulose acetate usually has a heat resistance stabilizer such as an alkali metal (lithium, potassium, sodium, etc.) or a salt or compound thereof, an alkaline earth metal (calcium, magnesium, strontium, Barium etc.) or a salt thereof or a compound thereof.
  • a heat resistance stabilizer such as an alkali metal (lithium, potassium, sodium, etc.) or a salt or compound thereof, an alkaline earth metal (calcium, magnesium, strontium, Barium etc.) or a salt thereof or a compound thereof.
  • the alkaline earth metal such as calcium contained in normal cellulose acetate is about 30 to 200 ppm per gram of cellulose acetate.
  • content of the metal salt in a cellulose acetate can be quantified with the following method.
  • ⁇ Measurement of metal salt (calcium) content> (Pretreatment and measurement) About 500 mg of the sample is cut, put into a decomposition tube of a sealed microwave sample decomposition apparatus, 8 ml of nitric acid (ultra high purity reagent) manufactured by Kanto Chemical Co., Ltd. is added, a wet decomposed sample is prepared, and the sample is transferred to a polypropylene container After finishing to 50 ml with ultrapure water, Ca can be quantified with an inductively coupled plasma optical emission spectrometer (ICP-AES).
  • ICP-AES inductively coupled plasma optical emission spectrometer
  • UV absorber An ultraviolet absorber is preferably used for the retardation film of the present invention.
  • the ultraviolet absorber those excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and having little absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties.
  • ultraviolet absorber preferably used in the present invention include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like. However, it is not limited to these.
  • a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber that are highly transparent and excellent in preventing the deterioration of the polarizing plate and the liquid crystal are preferable, and unnecessary coloring is less.
  • a benzotriazole-based ultraviolet absorber is particularly preferably used.
  • the ultraviolet absorber having a distribution coefficient of 9.2 or more described in JP-A No. 2001-187825 improves the surface quality of a long film and is excellent in coating properties.
  • polymer ultraviolet absorber described in the general formula (1) or general formula (2) described in JP-A-6-148430 and the general formulas (3), (6), (7) of Japanese Patent Application No. 2000-156039 is also preferably used.
  • PUVA-30M manufactured by Otsuka Chemical Co., Ltd.
  • the like are commercially available.
  • Fine particles In order to impart slipperiness to the retardation film of the present invention, it is preferable to add fine particles.
  • the primary average particle diameter of the fine particles is preferably 20 nm or less, more preferably 5 to 16 nm, and particularly preferably 5 to 12 nm.
  • These fine particles preferably form secondary particles having a particle diameter of 0.1 to 5 ⁇ m and are contained in the retardation film, and the preferable average particle diameter is 0.1 to 2 ⁇ m, more preferably 0.2 to 0.6 ⁇ m.
  • irregularities having a height of about 0.1 to 1.0 ⁇ m are formed on the film surface, thereby providing appropriate slipperiness to the film surface.
  • the primary average particle diameter of the fine particles used in the present invention is measured by observing the particles with a transmission electron microscope (magnification of 500,000 to 2,000,000 times), observing 100 particles, measuring the particle diameter, and measuring the average. The value was taken as the primary average particle size.
  • the apparent specific gravity of the fine particles is preferably 70 g / liter or more, more preferably 90 to 200 g / liter, and particularly preferably 100 to 200 g / liter.
  • a larger apparent specific gravity makes it possible to make a high-concentration dispersion, which improves haze and agglomerates, and is preferable when preparing a dope having a high solid content concentration as in the present invention.
  • Silicon dioxide fine particles having an average primary particle diameter of 20 nm or less and an apparent specific gravity of 70 g / liter or more are, for example, a mixture of vaporized silicon tetrachloride and hydrogen burned in air at 1000 to 1200 ° C. Can be obtained. For example, it is marketed with the brand name of Aerosil 200V and Aerosil R972V (above, Nippon Aerosil Co., Ltd. product), and can use them.
  • the apparent specific gravity described above is calculated by the following equation by taking a certain amount of silicon dioxide fine particles in a graduated cylinder, measuring the weight at this time.
  • Apparent specific gravity (g / liter) silicon dioxide mass (g) / volume of silicon dioxide (liter) ⁇ Method for producing retardation film>
  • the retardation film of the present invention can be preferably used regardless of whether it is a film produced by a solution casting method or a film produced by a melt casting method.
  • the production of the retardation film of the present invention comprises a step of preparing a dope by dissolving cellulose acetate and an additive in a solvent, a step of casting a dope on an endless metal support, and a cast dope.
  • the step of drying as a web, the step of peeling from the metal support, the step of stretching or maintaining the width, the step of further drying, and the step of winding up the finished film are performed.
  • Dope adjustment process> The process for preparing the dope will be described.
  • the concentration of cellulose acetate in the dope is preferably higher because the drying load after casting on the metal support can be reduced. However, if the concentration of cellulose acetate is too high, the load during filtration increases and the filtration accuracy is poor. Become.
  • the concentration that achieves both of these is preferably 10 to 35% by mass, and more preferably 15 to 25% by mass.
  • the solvent used in the dope may be used alone or in combination of two or more. However, it is preferable to use a mixture of a good solvent and a poor solvent of cellulose acetate in terms of production efficiency, and there are many good solvents. This is preferable from the viewpoint of solubility of cellulose acetate.
  • a preferable range of the mixing ratio of the good solvent and the poor solvent is 70 to 98% by mass for the good solvent and 2 to 30% by mass for the poor solvent.
  • the good solvent and the poor solvent change depending on the average degree of acetylation (acetyl group substitution degree) of cellulose acetate.
  • acetyl group substitution degree acetyl group substitution degree 2.4
  • cellulose triacetate acetyl group substitution degree 2.9
  • the good solvent used in the present invention is not particularly limited, and examples thereof include organic halogen compounds such as methylene chloride, dioxolanes, acetone, methyl acetate, and methyl acetoacetate. Particularly preferred is methylene chloride or methyl acetate.
  • the poor solvent used in the present invention is not particularly limited, but for example, methanol, ethanol, n-butanol, cyclohexane, cyclohexanone and the like are preferably used.
  • the dope preferably contains 0.01 to 2% by mass of water.
  • the solvent used for dissolving cellulose acetate the solvent removed from the film by drying in the film forming process is recovered and reused.
  • the recovery solvent may contain trace amounts of additives added to cellulose acetate, such as plasticizers, UV absorbers, polymers, monomer components, etc., but these are preferably reused even if they are included. Can be purified and reused if necessary.
  • a general method can be used as a method for dissolving cellulose acetate when preparing the dope described above. When heating and pressurization are combined, it is possible to heat above the boiling point at normal pressure.
  • a method in which a cellulose ester is mixed with a poor solvent and wetted or swollen, and then a good solvent is added and dissolved is also preferably used.
  • Pressurization may be performed by a method of injecting an inert gas such as nitrogen gas or a method of increasing the vapor pressure of the solvent by heating. Heating is preferably performed from the outside.
  • a jacket type is preferable because temperature control is easy.
  • the heating temperature with the addition of the solvent is preferably higher from the viewpoint of the solubility of the cellulose ester, but if the heating temperature is too high, the required pressure increases and the productivity deteriorates.
  • the preferred heating temperature is 45 to 120 ° C, more preferably 60 to 110 ° C, and even more preferably 70 ° C to 105 ° C.
  • the pressure is adjusted so that the solvent does not boil at the set temperature.
  • a cooling dissolution method is also preferably used, whereby cellulose acetate can be dissolved in a solvent such as methyl acetate.
  • the cellulose acetate solution is filtered using a suitable filter medium such as filter paper.
  • a suitable filter medium such as filter paper.
  • the absolute filtration accuracy is small in order to remove insoluble matters and the like, but there is a problem that the filter medium is likely to be clogged if the absolute filtration accuracy is too small.
  • a filter medium with an absolute filtration accuracy of 0.008 mm or less is preferable, a filter medium with 0.001 to 0.008 mm is more preferable, and a filter medium with 0.003 to 0.006 mm is more preferable.
  • the material of the filter medium there are no particular restrictions on the material of the filter medium, and ordinary filter media can be used. However, plastic filter media such as polypropylene and Teflon (registered trademark), and metal filter media such as stainless steel do not drop off fibers. preferable.
  • the bright spot foreign matter is arranged in a crossed Nicols state with two polarizing plates, a retardation film or the like is placed between them, light is applied from one polarizing plate side, and observation is performed from the other polarizing plate side. It is a point (foreign matter) where light from the opposite side sometimes leaks, and the number of bright spots having a diameter of 0.01 mm or more is preferably 200 / cm 2 or less.
  • it is 100 pieces / cm 2 or less, further preferably 50 pieces / m 2 or less, and further preferably 0 to 10 pieces / cm 2 . Further, it is preferable that the number of bright spots of 0.01 mm or less is small.
  • the dope can be filtered by a normal method, but the method of filtering while heating at a temperature not lower than the boiling point of the solvent at normal pressure and in a range where the solvent does not boil under pressure is the filtration pressure before and after filtration.
  • the increase in the difference (referred to as differential pressure) is small and preferable.
  • a preferable temperature is 45 to 120 ° C, more preferably 45 to 70 ° C, and further preferably 45 to 55 ° C.
  • the filtration pressure is preferably 1.6 MPa or less, more preferably 1.2 MPa or less, and further preferably 1.0 MPa or less.
  • the metal support in the casting process is preferably a mirror-finished surface, and a stainless steel belt or a drum whose surface is plated with a casting is preferably used as the metal support.
  • the cast width can be 1 ⁇ 4m.
  • the surface temperature of the metal support in the casting step is ⁇ 50 ° C. to less than the boiling point of the solvent, and a higher temperature is preferable because the web drying speed can be increased. May deteriorate.
  • the preferred support temperature is 0 to 60 ° C, more preferably 25 to 55 ° C.
  • the method for controlling the temperature of the metal support is not particularly limited, but there are a method of blowing hot air or cold air, and a method of contacting hot water with the back side of the metal support.
  • the residual solvent amount when peeling the web from the metal support is preferably 10 to 150% by mass, more preferably 20 to 40% by mass or 60 to 130% by mass. Particularly preferred is 20 to 30% by mass or 70 to 120% by mass.
  • the amount of residual solvent is defined by the following formula.
  • Residual solvent amount (% by mass) ⁇ (MN) / N ⁇ ⁇ 100 M is the mass of a sample collected during or after the production of the web or film, and N is the mass after heating M at 115 ° C. for 1 hour.
  • the residual solvent amount is preferably 1% by mass or less, more preferably 0.1% by mass or less, Particularly preferred is 0 to 0.01% by mass.
  • a roll drying method (a method in which webs are alternately passed through a plurality of rolls arranged above and below) and a method in which the web is dried while being conveyed by a tenter method are employed.
  • the retardation film of the present invention it is particularly preferable to stretch in the width direction (lateral direction) by a tenter method in which both ends of the web are gripped by clips or the like. Peeling is preferably performed at a peeling tension of 300 N / m or less.
  • the means for drying the web is not particularly limited, and can be generally performed with hot air, infrared rays, a heating roll, microwave, or the like, but is preferably performed with hot air in terms of simplicity.
  • drying temperature in the web drying process is increased stepwise from 40 to 200 ° C.
  • the retardation film of the present invention preferably has a width of 1 to 4 m. Particularly, those having a width of 1.3 to 4 m are preferably used, and particularly preferably 1.3 to 3 m.
  • the retardation values Ro and Rth targeted by the present retardation film can be adjusted by the amount of sugar ester and polyester D to be added and the stretching ratio (control of tenter stretching and transport tension) during film production.
  • Biaxial stretching or uniaxial stretching can be performed sequentially or simultaneously with respect to the longitudinal direction (film forming direction) of the film and the direction orthogonal to the longitudinal direction of the film, that is, the width direction.
  • the draw ratios in the biaxial directions perpendicular to each other are preferably in the range of 0.8 to 1.5 times in the casting direction and 1.1 to 2.5 times in the width direction, respectively. It is preferable to carry out in the range of 0.8 to 1.0 times in the direction and 1.3 to 1.5 times in the width direction.
  • the stretching temperature is 140 ° C. to 200 ° C., and it is preferable that the stretching temperature is over 140 ° C. and 180 ° C. or less.
  • the residual solvent in the film is preferably 0 to 20% by mass, more preferably 5 to 15% by mass.
  • the tension applied in the film width direction during stretching is desirably 30 N / m or more and less than 100 N / m, and preferably 40 N / m or more and less than 80 N / m.
  • the method of stretching the web For example, a method in which a circumferential speed difference is applied to a plurality of rolls, and the roll circumferential speed difference is used to stretch the rolls in the vertical direction. Both ends of the web are fixed with clips and pins, and the interval between the clips and pins is increased in the traveling direction And a method of stretching in the vertical direction, a method of stretching in the horizontal direction and stretching in the horizontal direction, a method of stretching in the vertical and horizontal directions and stretching in both the vertical and horizontal directions, and the like. Of course, these methods may be used in combination.
  • a tenter it may be a pin tenter or a clip tenter.
  • heat setting at a temperature of 140 ° C. to 180 ° C. after the stretching step is also effective for obtaining the tear strength in the present invention.
  • the heat setting at a stretching temperature of 140 ° C. to 180 ° C. or 140 ° C. to 180 ° C. after the stretching step is a temperature range that is specifically effective for cellulose acetate having an acetyl group substitution degree of 2.1 to 2.6. is there.
  • ⁇ 1 is preferably ⁇ 1 ° or more and + 1 ° or less, ⁇ 0 More preferably, it is 3 ° or more and + 0.3 ° or less.
  • This ⁇ 1 can be defined as an orientation angle, and ⁇ 1 can be measured in an atmosphere of 23 ° C. and 55% RH using an automatic birefringence meter KOBRA-21ADH (Oji Scientific Instruments).
  • ⁇ 1 satisfying the above relationship can contribute to obtaining high luminance in a display image, suppressing or preventing light leakage, and contributing to obtaining faithful color reproduction in a color liquid crystal display device.
  • the water vapor transmission rate of the retardation film of the present invention is preferably 800 to 1600 g / m 2 ⁇ 24 h at 40 ° C.
  • the moisture permeability can be measured according to the method described in JIS Z 0208.
  • the breaking elongation of the retardation film of the present invention is preferably 10 to 80%, more preferably 20 to 50%.
  • the visible light transmittance of the retardation film of the present invention is preferably 90% or more, and more preferably 93% or more.
  • the haze of the retardation film of the present invention is preferably less than 1%, particularly preferably 0 to 0.2%.
  • the additive becomes a foreign substance and the film is caused by internal haze and internal scattering.
  • the internal haze is preferably less than 0.1%, particularly preferably from 0 to 0.05%.
  • This haze can be achieved by using a cellulose ester as a raw material for pulp and containing the sugar ester and polyester D of the present invention.
  • the retardation film of the present invention has a refractive index difference between 5 ⁇ 10 ⁇ 4 to 5 ⁇ 10 ⁇ 3 between one surface thereof and the opposite surface (also referred to as film surface or back surface). preferable.
  • the hard coat film can be provided with functional layers such as an antistatic layer, a backcoat layer, an antireflection layer, a slippery layer, an adhesive layer, an antiglare layer, and a barrier layer.
  • the hard coat film may be provided with a back coat layer on the surface of the base film opposite to the side on which the hard coat layer is provided in order to prevent curling and sticking.
  • examples of inorganic compounds include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, tin oxide, and oxide. Mention may be made of indium, zinc oxide, ITO, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate.
  • the particles contained in the back coat layer are preferably 0.1 to 50% by mass with respect to the binder.
  • the increase in haze when the backcoat layer is provided is preferably 1.5% or less, more preferably 0.5% or less, and particularly preferably 0.1% or less.
  • a cellulose ester resin such as diacetylcellulose is preferable.
  • the hard coat film can be used as an antireflection film having an external light antireflection function by coating an antireflection layer on the hard coat layer.
  • the antireflection layer is preferably laminated in consideration of the refractive index, the film thickness, the number of layers, the layer order, and the like so that the reflectance is reduced by optical interference.
  • the antireflection layer is preferably composed of a low refractive index layer having a refractive index lower than that of the support, or a combination of a high refractive index layer having a refractive index higher than that of the support and a low refractive index layer. Particularly preferably, it is an antireflection layer composed of three or more refractive index layers.
  • Three layers having different refractive indexes from the support side are divided into medium refractive index layers (high refractive index layers having a higher refractive index than the support). Are preferably laminated in the order of a layer having a lower refractive index) / a high refractive index layer / a low refractive index layer.
  • an antireflection layer having a layer structure of four or more layers in which two or more high refractive index layers and two or more low refractive index layers are alternately laminated is also preferably used.
  • the layer structure of the antireflection film the following structure can be considered, but it is not limited to this.
  • the refractive index layer preferably contains silica-based fine particles, and the refractive index thereof is lower than the refractive index of the base film as a support, and is in the range of 1.30 to 1.45 at 23 ° C. and wavelength of 550 nm. Preferably there is.
  • the film thickness of the low refractive index layer is preferably 5 nm to 0.5 ⁇ m, more preferably 10 nm to 0.3 ⁇ m, and most preferably 30 nm to 0.2 ⁇ m.
  • the composition for forming a low refractive index layer preferably contains at least one kind of particles having an outer shell layer and porous or hollow inside as silica-based fine particles.
  • the particles having the outer shell layer and porous or hollow inside are preferably hollow silica-based fine particles.
  • composition for forming a low refractive index layer may contain an organosilicon compound represented by the following general formula (OSi-1), a hydrolyzate thereof, or a polycondensate thereof.
  • OSi-1 organosilicon compound represented by the following general formula (OSi-1)
  • hydrolyzate thereof a hydrolyzate thereof
  • polycondensate thereof a polycondensate thereof.
  • R represents an alkyl group having 1 to 4 carbon atoms. Specifically, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane and the like are preferably used. In addition, a silane coupling agent, a curing agent, a surfactant and the like may be added as necessary.
  • ⁇ Polarizing plate> A polarizing plate using the retardation film of the present invention will be described. The polarizing plate can be produced by a general method.
  • the retardation film of the present invention is subjected to alkali saponification treatment, and the treated retardation film is bonded to at least one surface of a polarizer produced by immersing and stretching in an iodine solution using a completely saponified polyvinyl alcohol aqueous solution. Is preferred.
  • a hard coat film may be used on the other surface, or another polarizing plate protective film may be used.
  • polarizing plate protective films that can be preferably used include KC4UA, KC6UA, KC8UX2MW, KC4UX, KC5UX, KC4UY, KC8UY, KC12UR, KC4UEW, KC8UCR-3, KC8UCR-4, KC8UCR-5, KC4CCR-1, 2, KC8UE, KC4UE (manufactured by Konica Minolta Opto) and the like.
  • a polarizer which is a main component of a polarizing plate, is an element that allows only light of a plane of polarization in a certain direction to pass.
  • a typical polarizer currently known is a polyvinyl alcohol-based polarizing film, which is polyvinyl alcohol.
  • iodine is dyed on a system film
  • a dichroic dye is dyed, but it is not limited to this.
  • a polyvinyl alcohol aqueous solution is formed into a film and dyed by uniaxial stretching or dyed or uniaxially stretched and then preferably subjected to a durability treatment with a boron compound.
  • the retardation film of the present invention and one side of the hard coat film are bonded together to form a polarizing plate. It is preferably bonded with an aqueous adhesive mainly composed of completely saponified polyvinyl alcohol or the like.
  • the pressure-sensitive adhesive layer used on one side of the protective film to be bonded to the substrate of the liquid crystal cell is preferably optically transparent and exhibits moderate viscoelasticity and adhesive properties.
  • the adhesive layer include adhesives or adhesives such as acrylic copolymers, epoxy resins, polyurethane, silicone polymers, polyethers, butyral resins, polyamide resins, polyvinyl alcohol resins, and synthetic rubbers.
  • a film such as a drying method, a chemical curing method, a thermal curing method, a thermal melting method, a photocuring method, or the like can be formed and cured using a polymer such as the above.
  • the acrylic copolymer can be preferably used because it is most easy to control the physical properties of the adhesive and is excellent in transparency, weather resistance, durability and the like.
  • the retardation film of the present invention is incorporated in a polarizing plate, and is a reflection type, transmission type, transflective liquid crystal display device or TN type, STN type, OCB type, HAN type, VA type (PVA type, MVA type), IPS type. It is preferably used in liquid crystal display devices of various drive systems such as the OCB type and is particularly suitable for the VA type.
  • cellulose acetate D having an acetyl substitution degree of 2.4 and a viscosity average polymerization degree of 180 was obtained.
  • Synthesis example 2 Cellulose acetate was produced in the same manner as in Synthesis Example 1 except that the amount of calcium acetate and the amount of water added in the synthesis process were changed as shown in Table 1. The obtained cellulose acetates were designated as A to C and E to J. The amount of calcium acetate and the amount of water shown in Table 1 indicate parts by mass.
  • Example 1 ⁇ Cellulose Acetate Film 1: Production of PL1> (Silicon dioxide dispersion) Aerosil R812 (manufactured by Nippon Aerosil Co., Ltd.) 12 parts by mass (average diameter of primary particles 12 nm, apparent specific gravity 90 g / liter) 88 parts by mass of ethanol or more was stirred and mixed with a dissolver for 30 minutes, and then dispersed with Manton Gorin. 88 parts by mass of methylene chloride was added to the silicon dioxide dispersion while stirring, and the mixture was stirred and mixed for 30 minutes with a dissolver to prepare a silicon dioxide dispersion dilution.
  • Aerosil R812 manufactured by Nippon Aerosil Co., Ltd.
  • Tinuvin 109 (manufactured by Ciba Japan Co., Ltd.) 11 parts by mass Tinuvin 171 (manufactured by Ciba Japan Co., Ltd.) 5 parts by mass Methylene chloride 100 parts by mass Dissolved and filtered.
  • the dope solution was filtered with Finemet NF manufactured by Nippon Seisen Co., Ltd. in the film production line.
  • the inline additive solution was filtered with Finemet NF manufactured by Nippon Seisen Co., Ltd.
  • the solvent was evaporated until the residual solvent amount became 120%, and the stainless steel band support was peeled off.
  • the peeled cellulose ester web was evaporated at 35 ° C., slit to 1.65 m width, and then stretched by 1.05 times in the TD direction (direction perpendicular to the film transport direction) with a tenter. Drying was performed at a drying temperature of ° C. At this time, the residual solvent amount when starting stretching with a tenter was 30%.
  • drying is completed while transporting a drying zone of 110 ° C. and 120 ° C. with a number of rolls, slitting to a width of 1.5 m, and knurling of a width of 15 mm and an average height of 10 ⁇ m is performed on both ends of the film, and the average film thickness Produced a cellulose triacetate film 1 having a thickness of 60 ⁇ m.
  • Ro and Rth were 3 nm and 50 nm, respectively.
  • the following hard coat layer coating composition 1 is filtered through a polypropylene filter having a pore size of 0.4 ⁇ m to prepare a hard coat layer coating solution, which is applied using a micro gravure coater, after drying at 80 ° C., using an ultraviolet lamp, the illuminance of the irradiated portion is 80 mW / cm 2, thereby curing the coated layer with irradiation dose as 80 mJ / cm 2, to form a hard coat layer 1 dry thickness 9 .mu.m, Winding and roll-shaped hard coat film 1 were produced.
  • ⁇ Hardcoat layer coating composition 1> The following materials were stirred and mixed to obtain hard coat layer coating composition 1.
  • 6.0 parts by mass (as polyester urethane resin 2 .0 parts by mass)
  • Pentaerythritol triacrylate 30 parts by mass
  • Pentaerythritol tetraacrylate 30 parts by mass
  • Irgacure 184 manufactured by Ciba Japan, photopolymerization initiator
  • Irgacure 907 manufactured by Ciba Japan, photopolymerization initiator
  • 1.0 part by mass Polyether-modified polydimethylsiloxane (BYK-UV3510, manufactured by Big Chemie Japan) 2.0 parts by mass Propylene glycol monomethyl ether 150 parts by mass Methyl ethyl ketone 150 parts by mass
  • Fine particles (Aerosil R812 (Nippon Aerosil Co., Ltd.)) 11 parts by mass (average primary particle diameter 16 nm, apparent specific gravity 90 g / liter) 89 parts by mass or more of ethanol was stirred and mixed with a dissolver for 50 minutes, and then dispersed with Manton Gorin.
  • ⁇ Fine particle additive solution Cellulose ester A was added to a dissolution tank containing methylene chloride and heated to completely dissolve, and this was then added to Azumi filter paper No. 3 manufactured by Azumi Filter Paper Co., Ltd. Filtered using 244.
  • the fine particle dispersion was slowly added to the cellulose ester solution after filtration while sufficiently stirring. Further, the particles were dispersed by an attritor so that the secondary particles had a predetermined particle size. This was filtered through Finemet NF manufactured by Nippon Seisen Co., Ltd. to prepare a fine particle additive solution.
  • Methylene chloride 99 parts by mass Fine particle dispersion 11 parts by mass A main dope solution having the following composition was prepared. First, methylene chloride and ethanol were added to the pressure dissolution tank. Cellulose ester F was charged into a pressure dissolution tank containing a solvent while stirring. This was heated and stirred to dissolve completely, and a plasticizer and an ultraviolet absorber were added and dissolved.
  • the main dope solution was prepared by filtration using 244.
  • the solvent was evaporated until the residual solvent amount became 110%, and the stainless steel band support was peeled off.
  • the film was stretched so that the longitudinal (MD) stretch ratio was 1.0 times by applying tension at the time of peeling, and then both ends of the web were gripped by a tenter, and the stretch ratio in the width (TD) direction was 1.4. It extended
  • the tension in the width direction applied to the film at this time was 45 m / N.
  • composition of main dope solution Methylene chloride 390 parts by weight Ethanol 80 parts by weight Cellulose acetate C 35 parts by weight Cellulose acetate D 65 parts by weight Additive: Sugar ester compound 4 10 parts by weight Additive: Polyester D 21 2.5 parts by weight Composition of dope solution (cellulose acetate, Retardation films 102 to 119 were produced in the same manner as described above except that the additive was changed as shown in Table 2.
  • TPP triphenyl phosphate
  • AB represents the following triazine compound.
  • the obtained retardation film was measured for the in-plane retardation value Ro, the retardation value Rth in the thickness direction, the tear strength ratio and the internal haze / internal scattering by the following measurements. The results are shown in Table 3.
  • nxny and nz represent the refractive indexes in the principal axes x, y and z directions of the refractive index ellipsoid, respectively, and nx and ny represent the refractive index in the film in-plane direction, and nz represents the thickness direction of the film.
  • Refractive index, nx> ny, and d represents film thickness (nm).
  • the average refractive index was determined from the average value obtained by measurement.
  • the thickness d of the film was measured using a commercially available micrometer.
  • the tear strength in the film transport direction (MD direction) and the tear strength in the same width direction (TD direction) are determined by applying a tear load of the Elmendorf method in accordance with JISK7128 / 2-1991. Then, the samples conditioned at 23 ° C. 55% RH and 60 ° C. 10% RH for 24 hours were measured under the same atmosphere.
  • scattering means the haze of the whole film including the state (film surface haze) which does not dripping glycerol.
  • Haze meter (turbidity meter) (model: NDH 2000, manufactured by Nippon Denshoku Co., Ltd.)
  • the light source uses a 5V9W halogen bulb, and the light receiving unit uses a silicon photocell (with a relative visibility filter).
  • the value is 0.02 or less in the haze measurement of a film when a solvent having a refractive index of ⁇ 0.05 is used as the film interface.
  • the blank haze 1 of a measuring instrument other than a film is measured.
  • the glass and glycerin used in the above measurement are as follows.
  • the obtained PVA film had an average thickness of 25 ⁇ m, a moisture content of 4.4%, and a film width of 3 m.
  • the obtained PVA film was continuously treated in the order of pre-swelling, dyeing, uniaxial stretching by a wet method, fixing treatment, drying, and heat treatment to produce a polarizer.
  • the PVA film was preliminarily swollen in water at a temperature of 30 ° C. for 30 seconds, and immersed in an aqueous solution having an iodine concentration of 0.4 g / liter and a potassium iodide concentration of 40 g / liter at a temperature of 35 ° C. for 3 minutes. Subsequently, the film was uniaxially stretched 6 times in a 50% aqueous solution with a boric acid concentration of 4% under a tension of 700 N / m. The potassium iodide concentration was 40 g / liter, and the boric acid concentration was 40 g / liter. Then, it was immersed in an aqueous solution having a zinc chloride concentration of 10 g / liter and a temperature of 30 ° C. for 5 minutes for fixing treatment.
  • the obtained polarizer had an average thickness of 13 ⁇ m, a polarization performance of 43.0% transmittance, a polarization degree of 99.5%, and a dichroic ratio of 40.1.
  • Step 1 The aforementioned polarizer was immersed in a storage tank of a polyvinyl alcohol adhesive solution having a solid content of 2% by mass for 1 to 2 seconds.
  • Process 2 The alkali saponification process was implemented on the hard coat film which stuck the peelable protective film (product made from PET) to retardation film and the hard coat layer on the following conditions.
  • the excess adhesive adhered to the polarizer immersed in the polyvinyl alcohol adhesive solution in Step 1 is gently removed, and the retardation film and the hard coat film 1 are sandwiched between the polarizers as shown in FIG. Arranged.
  • Step 3 The laminate was bonded with a rotating roller at a pressure of 20 to 30 N / cm 2 at a speed of about 2 m / min. At this time, it was carried out with care to prevent bubbles from entering.
  • Step 4 The sample prepared in Step 3 was dried in a dryer at a temperature of 80 ° C. for 5 minutes to prepare a polarizing plate.
  • Step 5 A commercially available acrylic pressure-sensitive adhesive is applied to the polarizing plate prepared in Step 4 so that the thickness after drying is 25 ⁇ m, and dried in an oven at 110 ° C. for 5 minutes to form an adhesive layer. A peelable protective film was attached to the film. This polarized light was cut (punched) into a size of 576 ⁇ 324 mm to produce a polarizing plate.
  • a hard coat film and a retardation film were arranged to produce polarizing plates 202 to 223.
  • the cellulose ester film 1 (PL1) was used as the retardation film.
  • the viewing side polarizing plate of the liquid crystal panel of the 40-inch display KDL-40V5 manufactured by Sony Corporation is peeled off, and the polarizing plate prepared above (see FIG. 5 for the configuration) is used as the polarizing plate instead so that the hard coat layer is on the viewing side. Then, the pressure-sensitive adhesive layer and the liquid crystal cell glass were bonded to prepare liquid crystal display devices 401 to 423.
  • Front contrast (brightness of white display measured from normal direction of display device) / (brightness of black display measured from normal direction of display device) The results obtained are shown in Table 4.

Abstract

L'invention vise à proposer un film de retard long qui est physiquement stable à la fois sous des conditions environnementales durant la production et durant le traitement. À cet effet, il est proposé selon l'invention, un film de retard allongé - qui utilise de l'acétate de cellulose et dont le retard (Ro) dans la direction dans le plan représenté par la formule mentionnée ci-dessous est de 30 à 150 nm et le rapport (Rth/Ro) du retard (Rth) dans la direction de l'épaisseur par rapport au retard mentionné précédemment (Ro) dans la direction dans le plan est supérieur à 0,8 - caractérisé par le degré de substitution de groupes acétyle de l'acétate de cellulose mentionné précédemment qui se situe entre 2,1 et 2,6 inclus, et par le rapport (résistance à la déchirure dans le sens machine MD/résistance à la déchirure dans le sens transversal (TD) entre la résistance à la déchirure dans la direction de la longueur (sens MD) du film de retard mentionné précédemment et la résistance à la déchirure dans le sens de la largeur (sens TD) de celui-ci étant de 0,8 à 1,2 dans les conditions à la fois de 23°C/55 %HR et de 60°C/10 %HR. Ro=(nx-ny)×d, Rth={(nx+ny)/2-nz}×d
PCT/JP2010/053057 2010-02-26 2010-02-26 Film de retard et procédé de production du film de retard WO2011104855A1 (fr)

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JP4900540B1 (ja) * 2010-04-28 2012-03-21 コニカミノルタオプト株式会社 セルロースアセテートフィルム、及びそれを用いた偏光板、液晶表示装置
JP5146628B1 (ja) * 2012-05-01 2013-02-20 コニカミノルタアドバンストレイヤー株式会社 位相差フィルム、偏光板の製造方法および液晶表示装置
WO2017141938A1 (fr) * 2016-02-15 2017-08-24 ダイセルポリマー株式会社 Composition d'acétate de cellulose

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JP2007313888A (ja) * 2006-04-28 2007-12-06 Konica Minolta Opto Inc 凹凸構造が設けられた光学フィルムの製造方法、光学フィルム、ワイヤグリッド偏光子、及び位相差フィルム
JP2008089855A (ja) * 2006-09-29 2008-04-17 Fujifilm Corp 光学補償フィルム、偏光板、及び液晶表示装置
JP2010001383A (ja) * 2008-06-20 2010-01-07 Konica Minolta Opto Inc 光学フィルム、及び偏光板

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JP4900540B1 (ja) * 2010-04-28 2012-03-21 コニカミノルタオプト株式会社 セルロースアセテートフィルム、及びそれを用いた偏光板、液晶表示装置
JP5146628B1 (ja) * 2012-05-01 2013-02-20 コニカミノルタアドバンストレイヤー株式会社 位相差フィルム、偏光板の製造方法および液晶表示装置
KR101291441B1 (ko) 2012-05-01 2013-07-30 코니카 미놀타 어드밴스드 레이어즈 인코포레이티드 위상차 필름, 편광판의 제조 방법 및 액정 표시 장치
WO2013164868A1 (fr) * 2012-05-01 2013-11-07 コニカミノルタ株式会社 Film de retard optique, procédé pour la production d'un polariseur et dispositif d'affichage à cristaux liquides
CN104272147A (zh) * 2012-05-01 2015-01-07 柯尼卡美能达株式会社 相位差膜、偏振片的制造方法及液晶显示装置
WO2017141938A1 (fr) * 2016-02-15 2017-08-24 ダイセルポリマー株式会社 Composition d'acétate de cellulose
CN108699292A (zh) * 2016-02-15 2018-10-23 大赛璐塑料株式会社 乙酸纤维素组合物

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