WO2013065307A1 - 位相差フィルム、偏光板および液晶表示装置 - Google Patents
位相差フィルム、偏光板および液晶表示装置 Download PDFInfo
- Publication number
- WO2013065307A1 WO2013065307A1 PCT/JP2012/007004 JP2012007004W WO2013065307A1 WO 2013065307 A1 WO2013065307 A1 WO 2013065307A1 JP 2012007004 W JP2012007004 W JP 2012007004W WO 2013065307 A1 WO2013065307 A1 WO 2013065307A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- film
- acid
- cellulose acetate
- retardation film
- retardation
- Prior art date
Links
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/13363—Birefringent elements, e.g. for optical compensation
-
- 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
- C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
- C08K5/0016—Plasticisers
-
- 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
- C08K5/04—Oxygen-containing compounds
- C08K5/10—Esters; Ether-esters
- C08K5/101—Esters; Ether-esters of monocarboxylic acids
- C08K5/103—Esters; Ether-esters of monocarboxylic acids with polyalcohols
-
- 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
- C08K5/04—Oxygen-containing compounds
- C08K5/10—Esters; Ether-esters
- C08K5/11—Esters; Ether-esters of acyclic polycarboxylic acids
-
- 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
- C08L1/12—Cellulose acetate
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/30—Polarising elements
- G02B5/3083—Birefringent or phase retarding elements
-
- 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
- C08J2301/10—Esters of organic acids
- C08J2301/12—Cellulose acetate
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
Definitions
- the present invention relates to a retardation film, a polarizing plate, and a liquid crystal display device. More specifically, the present invention relates to a retardation film obtained by stretching a cellulose acetate film containing a low-substituted cellulose acetate, a polarizing plate, and a liquid crystal display device.
- a retardation film having a specific retardation value (hereinafter referred to as an R value) and a combination thereof have been used to improve the viewing angle and color change of a liquid crystal display device.
- cellulose acetate is advantageous as the main raw material for such a retardation film, and that the optical properties of the film depend on the degree of acetyl substitution of cellulose acetate.
- cellulose acetate with a low degree of substitution has a high intrinsic birefringence, it is thought that by reducing the degree of acetyl substitution, it is possible to realize high optical expression suitable as a retardation film for VA. ing.
- Patent Documents 1 to 4 by immersing the surface in an alkaline aqueous solution to saponify and hydrophilize, the surface can be directly bonded to a polarizer mainly composed of polyvinyl alcohol. For this reason, it is used as a film (hereinafter referred to as a retardation film) to which a retardation compensation function of a polarizer is added.
- the polarizer with the retardation film is incorporated together with the liquid crystal cell when the liquid crystal display device is manufactured. At this time, since the retardation film is disposed between the polarizer and the liquid crystal cell, the optical characteristics of the film greatly affect the visibility of the liquid crystal display device.
- the retardation film is required to exhibit stable optical characteristics against various environmental changes.
- an object of the present invention is to provide a cellulose acetate film that has a small retardation change with respect to a residual solvent during film stretching and is excellent in pasting property with a polarizer. And it aims at providing the highly reliable polarizing plate and liquid crystal display device which used it as retardation film.
- Cellulose acetate ⁇ having an acetyl substitution degree of 2.1 or less, cellulose acetate ⁇ having an acetyl substitution degree of 2.3 to 2.5, and 5 to 5 to the total of the cellulose acetate ⁇ and the cellulose acetate ⁇ containing the compound is 10 wt% van der Waals volume of 500 ⁇ 3 or more 1000 ⁇ 3 or less, a retardation film is stretched.
- the following compound is a compound represented by any of the following general formula (I) ⁇ (V), [1] The retardation film according.
- A represents an aromatic ring or a cyclohexyl ring
- R 1 represents a hydrogen atom or an alkyl substituent
- R 2 represents an alkyl substituent or an alkoxyl substituent
- m represents an integer of 0 or more
- n represents 2 to 4
- R 3 represents a hydrogen atom or an alkyl substituent
- R 4 represents an alkyl substituent
- n represents 2 to 4
- B represents an aromatic ring or a cyclohexyl ring
- R 5 represents an alkyl substituent or an alkoxy substituent
- m represents an integer of 0 or more
- n represents 4 to 6
- R 6 represents an alkyl substituent.
- N represents 4-6.
- D represents an arylcarboxylic acid residue, an alkylcarboxylic acid residue, or a hydrogen atom
- E represents an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or a carbon number.
- F represents an alkylene dicarboxylic acid residue having 4 to 12 carbon atoms or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms
- n represents 2 to 4
- In-plane retardation Re at a measurement wavelength of 590 nm is 25 nm ⁇
- Y / X is 1 nm /% to 3 nm /% when the amount of decrease in Re when the residual solvent amount at the start of stretching is increased by X (%) is Y (nm), [1] or [ [2] The retardation film according to [2].
- the present invention it is possible to provide a cellulose acetate film in which the fluctuation range of the retardation value is minimized with respect to the change in the residual solvent amount of the film at the time of stretching, which could not be realized with the conventional cellulose acetate film.
- the adhesiveness with a hydrophilic film can be made high by carrying out the alkali treatment of the surface of the said cellulose acetate film. Therefore, the cellulose acetate film can be bonded to a polarizer as a retardation film to form a polarizing plate.
- the retardation film of the present invention (hereinafter also referred to as the film of the present invention) comprises cellulose acetate ⁇ having an acetyl substitution degree of 2.1 or less, cellulose acetate ⁇ having an acetyl substitution degree of 2.3 to 2.5, and a fan. and a Deruwarusu volume 500 ⁇ 3 or more 1000 ⁇ 3 the following compounds, and is stretched.
- the retardation film of the present invention because it is drawn by adding the van der Waals volume of 500 ⁇ 3 or more 1000 ⁇ 3
- the following compounds technically inevitable in the casting process, the residual solvent in the film during stretching Even when the amount has changed, the influence of the optical characteristics of the stretched film (retardation film) can be suppressed, and variations in optical expression can be suppressed.
- the retardation film of the present invention has high adhesiveness with a hydrophilic film and very little variation in optical characteristics.
- Cellulose acetate examples of cellulose used as a raw material for cellulose acetate ⁇ and cellulose acetate ⁇ contained in the retardation film of the present invention include cotton linter and wood pulp (hardwood pulp, conifer pulp). Cellulose acetate obtained from any raw material cellulose may be used, and in some cases, it may be mixed and used. Detailed descriptions of these raw material celluloses can be found in, for example, Marusawa and Uda, “Plastic Materials Course (17) Fibrous Resin”, published by Nikkan Kogyo Shimbun (published in 1970), and the Japan Society of Invention and Innovation Technical Bulletin No. 2001. The cellulose described in No.-1745 (pages 7 to 8) can be used.
- the cellulose acetate ⁇ and cellulose acetate ⁇ contained in the retardation film of the present invention are preferably obtained from wood pulp from the viewpoint of bonding properties with a polarizer.
- the glucose unit having ⁇ -1,4 bonding constituting cellulose has free hydroxyl groups (hydroxyl groups) at the 2nd, 3rd and 6th positions.
- Cellulose acetate is a polymer obtained by acetylating part or all of these hydroxyl groups (hydroxyl groups) with acetyl groups.
- the degree of acetyl group substitution means the proportion of cellulose hydroxyl groups (hydroxyl groups) located at the 2-position, 3-position and 6-position (acetylation of 100% is substitution degree 3).
- the cellulose acetate ⁇ and cellulose acetate ⁇ contained in the retardation film of the present invention are not particularly limited as long as the degree of acetyl group substitution satisfies the above range.
- the degree of acetyl substitution of cellulose acetate ⁇ is more preferably 1.5 to 2.1, and more preferably 1.8 to 2.1. Cellulose acetate having an acetyl substitution degree in this range is easier to obtain adhesion with a hydrophilic film.
- the retardation film of the present invention contains cellulose acetate ⁇ and cellulose acetate ⁇ , and the degree of acetyl substitution of each cellulose acetate contained in the retardation film is measured by liquid chromatography as described in Examples below. Can be confirmed.
- Cellulose acetate is usually 1) an activation step for activating cellulose, 2) an acetylation step for esterifying cellulose with acetic acid, and 3) saponification for adjusting the degree of acetylation by hydrolyzing the obtained cellulose triacetate.
- -It can be synthesized through an aging process.
- Cellulose acetate containing cellulose acetate ⁇ and cellulose acetate ⁇ can be obtained by adjusting the pH and temperature conditions of the acetic acid-containing aqueous solution in, for example, 3) the saponification / ripening step in the above synthesis process.
- an organic acid such as acetic acid or methylene chloride is used as an organic solvent as a reaction solvent.
- acetylation catalyst when the acetylating agent is an acid anhydride, a protic catalyst such as sulfuric acid is preferably used, and when the acetylating agent is an acid chloride (for example, CH 3 COCl). Basic compounds are used.
- cellulose fatty acid ester contains cellulose containing fatty acid corresponding to acetyl group and other acyl groups (acetic acid, propionic acid, valeric acid, etc.) or their anhydrides This is a method of acylating with a mixed organic acid component.
- the cellulose acetate used in the present invention can be synthesized, for example, by the method described in JP-A-10-45804.
- the retardation film of the present invention contains a compound having a van der Waals volume of 500 to 3 to 1000 to 3 .
- the retardation film of the present invention it is required to reduce the fluctuation of the retardation value of the retardation film with respect to the change in the residual solvent amount during film stretching.
- it is effective to reduce the intermolecular hydrogen bonding action of cellulose acetate in the film.
- the degree of acetyl substitution may be increased.
- it becomes difficult to obtain a desired retardation value. That is, in order to stably obtain a desired retardation value, it is necessary to reconcile seemingly contradictory issues such as reducing the acetyl substitution degree of cellulose acetate and suppressing the hydrogen bonding action of cellulose acetate.
- van der Waals volume is added 500 ⁇ 3 or more 1000 ⁇ 3 the following compounds. If out of this range, in any case, the optical compensation performance as a retardation film becomes insufficient.
- Van der Waals volume is a parameter obtained using molecular simulation software Cerius 2 manufactured by Accelrys.
- the molecular value is optimized by MM calculation using Drying
- Examples of compounds having a van der Waals volume of 500 3 or more and 1000 3 or less are represented by the following general formulas (I to IV).
- A represents an aromatic ring (for example, having 6 to 10 carbon atoms) or a cyclohexyl ring.
- R 1 represents a hydrogen atom or an alkyl substituent (eg, having 1 to 10 carbon atoms)
- R 2 is a substituent that the aromatic ring or cyclohexyl ring of A has, and an alkyl substituent (eg, having 1 to 10 carbon atoms) Or an alkoxyl substituent (for example, having 1 to 10 carbon atoms).
- m represents the number of substituents R 2 contained in the aromatic ring or cyclohexyl ring of A, and represents an integer of 0 or more, preferably 0 to 3.
- n represents 2 to 4.
- R 3 represents a hydrogen atom or an alkyl substituent (for example, 1 to 10 carbon atoms), and R 4 represents an alkyl substituent (for example, 1 to 10 carbon atoms).
- n represents 2 to 4.
- B represents an aromatic ring or a cyclohexyl ring
- R 5 represents a substituent that the aromatic ring or cyclohexyl ring of B has, an alkyl substituent (for example, 1 to 10 carbon atoms) or an alkoxy substituent. (For example, having 1 to 10 carbon atoms).
- m represents the number of substituents R 5 possessed by the aromatic ring or cyclohexyl ring of B, and represents an integer of 0 or more, preferably 0 to 3.
- n represents 4-6.
- R 6 represents an alkyl substituent (for example, having 1 to 10 carbon atoms).
- n represents 4-6.
- the compound represented by the general formulas (I to IV) is an esterified product of a trihydric or higher aliphatic polyhydric alcohol and a monocarboxylic acid.
- Preferred examples of the aliphatic polyhydric alcohol include adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6-hexanediol, hexanetriol Galactitol, mannitol, 3-methylpentane-1,3,5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, xylitol and the like, but are not limited thereto.
- the monocarboxylic acid used in the polyhydric alcohol ester is not particularly limited, and known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid and the like can be used. Use of an alicyclic monocarboxylic acid or aromatic monocarboxylic acid is preferred in terms of improving moisture permeability and retention.
- aliphatic monocarboxylic acid a fatty acid having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used, but it is not particularly limited.
- the number of carbon atoms is more preferably 1-20, and particularly preferably 1-10.
- acetic acid is contained, the compatibility with the cellulose ester is increased, and it is also preferable to use a mixture of acetic acid and another monocarboxylic acid.
- Examples of preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanoic acid, undecylic acid, lauric acid, tridecyl Acids, 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, laccelic acid, etc., undecylenic acid , Unsaturated fatty acids such as oleic acid, sorbic acid, linoleic acid, linolenic acid and arachidonic acid.
- Examples of preferred alicyclic monocarboxylic acids include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid, or derivatives thereof.
- Examples of preferred aromatic monocarboxylic acids include those in which 1 to 3 alkoxy groups such as alkyl group, methoxy group or ethoxy group are introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, biphenylcarboxylic acid, Aromatic monocarboxylic acids having two or more benzene rings such as naphthalenecarboxylic acid and tetralincarboxylic acid, or derivatives thereof are included. Benzoic acid is particularly preferable.
- the carboxylic acid used in the polyhydric alcohol ester may be one kind or a mixture of two or more kinds. Moreover, all the OH groups in the polyhydric alcohol may be esterified, or a part of the OH groups may be left as they are.
- the molecular weight of the compound represented by the general formulas (I to IV) is preferably 500 to 1200.
- a large molecular weight is preferable because it is difficult to volatilize; on the other hand, a smaller molecular weight is preferable in terms of moisture permeability and compatibility with cellulose ester.
- V Another example of a compound having a van der Waals volume of 500 3 or more and 1000 3 or less is represented by the following general formula (V).
- D represents an aryl carboxylic acid residue, an alkyl carboxylic acid residue, a hydrogen atom
- E represents an alkylene glycol residue having 2 to 12 carbon atoms or an aryl glycol residue having 6 to 12 carbon atoms.
- F represents an alkylene dicarboxylic acid residue having 4 to 12 carbon atoms or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms
- n represents 2 to 4.
- the compound represented by the general formula (V) is generally obtained by copolymerizing a monomer having an aromatic ring.
- the monomer having an aromatic ring is at least one monomer selected from aromatic dicarboxylic acids having 8 to 20 carbon atoms and aromatic diols having 6 to 20 carbon atoms.
- aromatic dicarboxylic acids having 8 to 20 carbon atoms include phthalic acid, terephthalic acid, isophthalic acid, 1,5-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2, Examples include 8-naphthalenedicarboxylic acid and 2,6-naphthalenedicarboxylic acid.
- preferred aromatic dicarboxylic acids are phthalic acid, terephthalic acid, and isophthalic acid.
- aromatic diols having 6 to 20 carbon atoms examples include bisphenol A, 1,2-hydroxybenzene, 1,3-hydroxybenzene, 1,4-hydroxybenzene, and 1,4-benzenedimethanol. It is not limited. Bisphenol A, 1,4-hydroxybenzene and 1,4-benzenedimethanol are preferred.
- the retardation film of the present invention as the van der Waals volume of 500 ⁇ 3 or more 1000 ⁇ 3
- the following compounds it is preferable to include one or two or more combinations of the compound represented by the general formula (I) ⁇ (V).
- the combination is not particularly limited, and several types of each component may be combined.
- the retardation film of this invention contains the compound represented by general formula (I), (III) or (V).
- the terminal is sealed with an alkyl group or an aromatic group.
- the addition amount of the compound having a van der Waals volume of 500 3 or more and 1000 3 or less is preferably 5 to 10% by mass with respect to cellulose acetate (total of cellulose acetate ⁇ and cellulose acetate ⁇ ).
- the addition amount 5% by mass or more By making the addition amount 5% by mass or more, the hydrogen bonding action of cellulose acetate can be sufficiently suppressed.
- By setting the addition amount to 10% by mass or less bleeding out, an increase in haze, and the like can be suppressed.
- a plasticizer an antioxidant (deterioration inhibitor), an ultraviolet absorber, a peeling accelerator, a matting agent, a lubricant, the above-described plasticizer, and the like can be appropriately used as necessary.
- plasticizer examples of the plasticizer contained in the retardation film of the present invention include phthalic acid esters, phosphoric acid esters, polyhydric alcohol esters, and the like.
- the addition amount of the plasticizer is preferably 0.5 to 30% by mass, particularly preferably 5 to 20% by mass with respect to the cellulose ester.
- the polyhydric alcohol ester plasticizer is a plasticizer composed of an ester of a divalent or higher aliphatic polyhydric alcohol and a monocarboxylic acid, and preferably has an aromatic ring or a cycloalkyl ring in the molecule.
- a divalent to 20-valent aliphatic polyhydric alcohol ester is preferred.
- the polyhydric alcohol constituting the polyhydric alcohol ester plasticizer is represented by the following general formula (a) “Ra- (OH) n”.
- Ra represents an n-valent organic group
- n represents a positive integer of 2 or more
- an OH group represents an alcoholic or phenolic hydroxyl group.
- Examples of preferable polyhydric alcohol constituting the polyhydric alcohol ester plasticizer include adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, Dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1, , 6-hexanediol, hexanetriol, galactitol, mannitol, 3-methylpentane-1,3,5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, xylitol, and the like, but are not particularly limited. In particular, triethylene glycol, tetraethylene glycol, di
- Examples of monocarboxylic acids constituting the polyhydric alcohol ester plasticizer are not particularly limited, and known aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, aromatic monocarboxylic acids and the like can be used. Use of an alicyclic monocarboxylic acid or aromatic monocarboxylic acid is preferred in terms of improving moisture permeability and retention.
- Examples of preferable monocarboxylic acid include, but are not limited to, the following.
- Examples of the aliphatic monocarboxylic acid include fatty acids having a straight chain or a side chain having 1 to 32 carbon atoms.
- the number of carbon atoms is more preferably 1-20, and particularly preferably 1-10.
- acetic acid is contained, the compatibility with the cellulose ester is increased, and it is also preferable to use a mixture of acetic acid and another monocarboxylic acid.
- Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanoic acid, undecylic acid, lauric acid, tridecylic acid, Saturated fatty acids such as 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, laccelic acid, undecylenic acid, olein Examples thereof include unsaturated fatty acids such as acid, sorbic acid, linoleic acid, linolenic acid, and arachidonic acid.
- Examples of preferable alicyclic monocarboxylic acids include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid, or derivatives thereof.
- aromatic monocarboxylic acids examples include those in which 1 to 3 alkoxy groups such as alkyl group, methoxy group or ethoxy group are introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, biphenylcarboxylic acid, Aromatic monocarboxylic acids having two or more benzene rings such as naphthalenecarboxylic acid and tetralincarboxylic acid, or derivatives thereof are included. Benzoic acid is particularly preferable.
- the carboxylic acid constituting the ester of the polyhydric alcohol ester plasticizer may be one kind or a combination of two or more kinds. Moreover, all the OH groups in the polyhydric alcohol may be esterified, or a part of the OH groups may be left as they are.
- the molecular weight of the polyhydric alcohol ester plasticizer is not particularly limited, but is preferably 300 to 1500, and more preferably 350 to 750. A higher molecular weight is preferred because it is less likely to volatilize, and a smaller one is preferred in terms of moisture permeability and compatibility with cellulose ester.
- phthalate ester plasticizer examples include diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, dicyclohexyl terephthalate and the like.
- phosphate ester plasticizer examples include triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate and the like.
- the retardation film of the present invention may contain a known deterioration (oxidation) inhibitor.
- degradation (oxidation) inhibitors include 2,6-di-tert-butyl-4-methylphenol, 4,4′-thiobis- (6-tert-butyl-3-methylphenol), 1,1 ′ -Bis (4-hydroxyphenyl) cyclohexane, 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 2,5-di-tert-butylhydroquinone, pentaerythrityl-tetrakis [3- (3, Phenolic antioxidants or hydroquinone antioxidants such as 5-di-tert-butyl-4-hydroxyphenyl) propionate].
- tris (4-methoxy-3,5-diphenyl) phosphite tris (nonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, bis (2,6-di-tert) Phosphorous antioxidants such as -butyl-4-methylphenyl) pentaerythritol diphosphite and bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite are preferred.
- the addition amount of the deterioration inhibitor is 0.05 to 5.0 parts by mass with respect to 100 parts by mass of the cellulose resin.
- the retardation film of the present invention preferably contains an ultraviolet absorber from the viewpoint of preventing deterioration of the polarizing plate or the liquid crystal.
- an 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.
- preferable ultraviolet absorbers include hindered phenol compounds, hydroxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like.
- hindered phenol compounds examples include 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate].
- benzotriazole compounds include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol), (2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5- Triazine, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], N, N′-hexamethylenebis (3,5-di-tert-butyl-4- Hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 2- (2′-hydroxy-3 ′, 5 '-Di-tert-butylphenyl) -5-chloro
- the addition amount of these ultraviolet light inhibitors is preferably 1 ppm to 1.0%, more preferably 10 to 1000 ppm in terms of mass ratio to the entire retardation film.
- the retardation film of the present invention preferably contains a release accelerator from the viewpoint of improving the peelability.
- the content of the peeling accelerator is, for example, 0.001 to 1% by mass, preferably 0.005 to 0.5% by mass, and more preferably 0.01 to 0.3% by mass. .
- a content of 1% by mass or less is preferable because separation of the release agent from the film is difficult to occur. If it is 0.005 mass% or more, a desired peeling reduction effect can be obtained, which is preferable.
- peeling accelerator known ones can be used, and organic and inorganic acidic compounds, surfactants, chelating agents and the like can be used. Among them, polyvalent carboxylic acids and esters thereof are effective, and in particular, ethyl esters of citric acid can be used effectively.
- Fine particles may be added to the retardation film of the present invention in order to prevent it from being damaged or deteriorated in transportability when handled. They are called matting agents, anti-blocking agents or anti-scratching agents and have been used conventionally. They are not particularly limited as long as they have the above-described functions, and may be an inorganic compound matting agent or an organic compound matting agent.
- the inorganic compound matting agent include silicon-containing inorganic compounds (for example, silicon dioxide, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, etc.), titanium oxide, zinc oxide, Examples include aluminum oxide, barium oxide, zirconium oxide, strongtium oxide, antimony oxide, tin oxide, tin oxide / antimony, calcium carbonate, talc, clay, calcined kaolin, and calcium phosphate.
- silicon-containing inorganic compounds for example, silicon dioxide, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, etc.
- titanium oxide zinc oxide
- Examples include aluminum oxide, barium oxide, zirconium oxide, strongtium oxide, antimony oxide, tin oxide, tin oxide / antimony, calcium carbonate, talc, clay, calcined kaolin, and calcium phosphate.
- the inorganic compound matting agent are silicon-containing inorganic compounds and zirconium oxide, and silicon dioxide is particularly preferable because the turbidity of the cellulose acylate film can be reduced.
- silicon dioxide fine particles for example, commercially available products having trade names such as Aerosil R972, R974, R812, 200, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.) can be used.
- the zirconium oxide fine particles for example, those commercially available under trade names such as Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) can be used.
- organic compound matting agent examples include polymers such as silicone resin, fluorine resin and acrylic resin, and among them, silicone resin is preferable. Further, among the silicone resins, those having a three-dimensional network structure are particularly preferable. For example, Tospearl 103, Tospearl 105, Tospearl 108, Tospearl 120, Tospearl 145, Tospearl 3120, and Tospearl 240 (above manufactured by Toshiba Silicone Co., Ltd.) ) Etc. can be used.
- the content of the matting agent in the retardation film of the present invention is preferably 0.01 to 5.0% by mass, more preferably 0.03 to 3.0% by mass, A ratio of 0.05 to 1.0% by mass is particularly preferable.
- the retardation of the retardation film of the present invention (in-plane retardation Re and retardation Rth in the film thickness direction) is appropriately selected depending on the design of the liquid crystal cell and the optical film.
- the in-plane retardation Re is preferably 25 nm ⁇
- the retardation Rth in the film thickness direction is preferably 50 nm ⁇
- Re is more preferably 40 nm ⁇
- the Rth is more preferably 70 nm ⁇
- In-plane retardation Re ( ⁇ ) and retardation Rth ( ⁇ ) in the film thickness direction represent in-plane retardation and retardation in the film thickness direction at wavelength ⁇ , respectively.
- the wavelength ⁇ is 590 nm.
- the in-plane retardation Re ( ⁇ ) is measured by making light having a wavelength of ⁇ nm incident in the normal direction of the film in KOBRA 21ADH (manufactured by Oji Scientific Instruments).
- Rth ( ⁇ ) in the film thickness direction is obtained by setting the in-plane retardation Re ( ⁇ ) to the in-plane slow axis (determined by KOBRA 21ADH) as the tilt axis (rotary axis) (when there is no slow axis). Is the rotation axis in any direction in the film plane), and in steps of 10 degrees from the normal direction to 50 degrees on one side with respect to the film normal direction, light of wavelength ⁇ nm is incident from each inclined direction. Measure 6 points. KOBRA ⁇ 21ADH is calculated based on the measured retardation value, the assumed value of the average refractive index, and the input film thickness value.
- the retardation value is measured from any two directions with the slow axis as the tilt axis (rotation axis) (in the absence of the slow axis, the arbitrary direction in the film plane is the rotation axis), and the value Rth can also be calculated from the following formula (A) and formula (B) based on the assumed average refractive index and the input film thickness value.
- Re ( ⁇ ) represents a retardation value in a direction inclined by an angle ⁇ from the normal direction.
- d represents the film thickness.
- an average refractive index n is required as a parameter, and a value measured by an Abbe refractometer (“Abbe refractometer 2-T” manufactured by Atago Co., Ltd.) is used.
- the NZ factor represented by the following formula (7) is preferably 7 or less, more preferably 5.5 or less, and particularly preferably 4.5 or less.
- the Nz factor is appropriately selected depending on the design of the liquid crystal cell and the optical film.
- the haze of the retardation film of the present invention is preferably less than 1%, and more preferably less than 0.5%. By setting the haze to less than 1%, there is an advantage that the transparency of the film becomes higher and it becomes easier to use as an optical film.
- the equilibrium moisture content (25 ° C., relative humidity 60%) of the retardation film of the present invention is preferably 4% or less, and more preferably 3% or less.
- the average moisture content is preferably 4% or less, it is easy to cope with changes in humidity, and the optical characteristics and dimensions are more difficult to change.
- the average film thickness of the retardation film of the present invention is preferably 30 to 100 ⁇ m, more preferably 30 to 80 ⁇ m, and still more preferably 30 to 70 ⁇ m.
- the average film thickness of the retardation film of the present invention is preferably 30 to 100 ⁇ m, more preferably 30 to 80 ⁇ m, and still more preferably 30 to 70 ⁇ m.
- the film width of the retardation film of the present invention is preferably 700 to 3000 mm, more preferably 1000 to 2800 mm, and particularly preferably 1500 to 2500 mm.
- the film of the present invention preferably has a film width of 700 to 3000 mm and ⁇ Re of 10 nm or less.
- a dope containing cellulose acetate satisfying the substitution degree and a compound satisfying the van der Waals volume is flowed on a support.
- the retardation film of the present invention is produced by forming a solution (dope) obtained by dissolving cellulose acetate in an organic solvent using a solvent cast method.
- the organic solvent for the dope may be a single type or a mixed solvent of two or more types of organic solvents.
- the doped organic solvent is selected from ethers having 3 to 12 carbon atoms, ketones having 3 to 12 carbon atoms, esters having 3 to 12 carbon atoms, and halogenated hydrocarbons having 1 to 6 carbon atoms. It is preferable to contain a solvent.
- the ether, ketone and ester may have a cyclic structure.
- a compound having two or more functional groups of ether, ketone and ester that is, —O—, —CO— and —COO— can also be used as the organic solvent.
- Examples of ethers having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetole.
- Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclohexanone and methylcyclohexanone.
- Examples of the esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate.
- the doped organic solvent may have another functional group such as an alcoholic hydroxyl group.
- the number of carbon atoms may be within the specified range of the compound having any functional group.
- the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol.
- the number of carbon atoms of the halogenated hydrocarbon is preferably 1 or 2, and most preferably 1.
- the halogen of the halogenated hydrocarbon is preferably chlorine.
- the proportion of halogen atoms in the halogenated hydrocarbon substituted with halogen is preferably 25 to 75 mol%, more preferably 30 to 70 mol%, and more preferably 35 to 65 mol%. More preferably, it is most preferably 40 to 60 mol%.
- Methylene chloride is a representative halogenated hydrocarbon.
- the dope can be prepared by a general method.
- a general method means processing at a temperature of 0 ° C. or higher (room temperature or high temperature).
- the dope can be prepared using a dope preparation method and apparatus in a normal solvent cast method.
- the content of cellulose acetate in the dope is preferably adjusted to 10 to 40% by mass, and more preferably 10 to 30% by mass.
- Arbitrary additives described later may be added to the organic solvent (main solvent).
- the dope can be prepared by stirring cellulose acetate, other components and an organic solvent at room temperature (0 to 40 ° C.). High concentration solutions may be stirred under pressure and heating conditions. Specifically, cellulose acetate, other components and an organic solvent are placed in a pressure vessel and sealed, and stirred while heating to a temperature not lower than the boiling point of the solvent at normal temperature and in a range where the solvent does not boil.
- the heating temperature is usually 40 ° C. or higher, preferably 60 to 200 ° C., more preferably 80 to 110 ° C.
- Cellulose acetate and other components may be roughly mixed in advance, and the resulting mixture may be charged into a container or sequentially.
- the container can be pressurized by injecting an inert gas such as nitrogen gas.
- a jacket type heating device can be used.
- the entire container can also be heated by providing a plate heater outside the container and piping to circulate the liquid.
- the container needs to be configured so that the contents of the container can be stirred.
- a stirring blade inside the container and use this to stir the contents.
- the stirring blade preferably has a length that reaches the vicinity of the wall of the container.
- a scraping blade is preferably provided at the end of the stirring blade in order to renew the liquid film on the vessel wall.
- instruments such as a pressure gauge and a thermometer may be installed. Each component is dissolved in a solvent in a container.
- the prepared dope is taken out of the container after cooling, or is taken out and cooled using a heat exchanger or the like.
- the dope can also be prepared by a cooling dissolution method.
- cellulose acetate can be dissolved in an organic solvent that is difficult to dissolve by a normal dissolution method.
- it is a solvent which can melt
- cellulose acetate is gradually added to an organic solvent with stirring at room temperature.
- the amount of cellulose acetate in the obtained mixture is preferably adjusted to 10 to 40% by mass.
- the amount of cellulose acetate is more preferably 10 to 30% by mass.
- the obtained mixture is cooled to ⁇ 100 to ⁇ 10 ° C. (preferably ⁇ 80 to ⁇ 10 ° C., more preferably ⁇ 50 to ⁇ 20 ° C., most preferably ⁇ 50 to ⁇ 30 ° C.).
- the cooling can be performed, for example, in a dry ice / methanol bath ( ⁇ 75 ° C.) or a cooled diethylene glycol solution ( ⁇ 30 to ⁇ 20 ° C.).
- a dry ice / methanol bath ⁇ 75 ° C.
- a cooled diethylene glycol solution ⁇ 30 to ⁇ 20 ° C.
- the cooling rate at this time is preferably 4 ° C./min or more, more preferably 8 ° C./min or more, and most preferably 12 ° C./min or more.
- 10,000 ° C./second is the theoretical upper limit
- 1000 ° C./second is the technical upper limit
- 100 ° C./second is the practical upper limit.
- the cooling rate is a value obtained by dividing the difference between the temperature at the start of cooling and the final cooling temperature by the time from the start of cooling to the final cooling temperature.
- the cellulose acetate dissolves in the organic solvent.
- the temperature may be increased by simply leaving it at room temperature or in a warm bath.
- the heating rate is preferably 4 ° C./min or more, more preferably 8 ° C./min or more, and most preferably 12 ° C./min or more. The higher the heating rate, the better. However, 10,000 ° C./second is the theoretical upper limit, 1000 ° C./second is the technical upper limit, and 100 ° C./second is the practical upper limit.
- the heating rate is a value obtained by dividing the difference between the temperature at the start of heating and the final heating temperature by the time from the start of heating until the final heating temperature is reached.
- a dope that is a uniform solution is obtained. If the solute is not sufficiently dissolved, the cooling and heating operations may be repeated. Whether or not the dissolution is sufficient can be judged by simply observing the appearance of the solution visually.
- the cooling and melting method it is desirable to use a sealed container in order to avoid moisture contamination due to condensation during cooling.
- the cooling and heating operation when the pressure is applied during cooling and the pressure is reduced during heating, the dissolution time can be shortened.
- DSC differential scanning calorimetry
- a 20% by mass solution of cellulose acetate (total acetyl substitution degree: 60.9%, viscosity average polymerization degree: 299) dissolved in methyl acetate by the cooling dissolution method is 33 ° C.
- this pseudo phase transition temperature varies depending on the total acetyl substitution degree, viscosity average polymerization degree, solution concentration, and organic solvent used in cellulose acetate.
- the method of adding the additive to the dope is not particularly limited, and any method may be used as long as a desired dope can be obtained.
- an additive may be blended at the stage of mixing cellulose acetate and a solvent, or an additive may be blended after preparing a mixed solution with cellulose acetate and a solvent.
- the method of adding an additive immediately before casting a dope is also called in-line addition.
- In-line addition is performed with a screw-type kneader installed online. Specifically, it is performed by a static mixer such as an in-line mixer.
- An example of the in-line mixer is preferably a static mixer SWJ (Toray static type in-pipe mixer Hi-Mixer) (manufactured by Toray Engineering).
- the distance L between the tip of the addition nozzle for mixing additive liquids of different compositions into the main raw material dope and the starting end of the in-line mixer is made not more than 5 times the main raw material pipe inner diameter d, concentration unevenness, aggregation of mat particles, etc. It is stated that it can be eliminated.
- the distance (L) between the tip opening of the supply nozzle of the additive liquid having a composition different from that of the main raw material dope and the start end of the in-line mixer is 10 It is described that it is less than double.
- an inline mixer a static unstirred in-tube mixer or a dynamic agitated in-tube mixer is described.
- Japanese Patent Application Laid-Open No. 2003-053752 discloses that the flow rate ratio of the cellulose acylate film main raw material dope / in-line additive solution is 10/1 to 500/1, preferably 50/1 to 200/1. Has been.
- Japanese Patent Application Laid-Open No. 2003-014933 discloses a method of adding an additive to a dope, a method of adding the additive into a melting pot, and dissolution of the additive or additive into the dope fed from the melting pot to a casting die.
- a method of adding a liquid or dispersion to a dope is disclosed. In the case of the latter method, it is described that it is preferable to provide a mixing means such as a static mixer in order to improve the mixing property.
- the dope is cast on a drum or band, and the solvent is evaporated to form a film.
- the concentration of the dope to be cast is preferably adjusted so that the solid content is 18 to 35% by mass.
- the surface of the drum or band is preferably finished in a mirror state.
- the casting and drying methods in the solvent casting method are described in U.S. Pat. Nos. 2,336,310, 2,367,603, 2,429,2078, 2,429,297, 2,429,978, 2,607,704, 2,273,069, and 2,739,070, British Patent 6,407,331.
- the dope is preferably cast on a drum or band having a surface temperature of 10 ° C. or less. After casting, it is preferable to dry it by applying air for 2 seconds or more. The obtained film can be peeled off from the drum or band and further dried with high-temperature air whose temperature is successively changed from 100 ° C. to 160 ° C. to evaporate the residual solvent.
- the above method is described in Japanese Patent Publication No. 5-17844. According to this method, it is possible to shorten the time from casting to stripping. In order to carry out this method, it is necessary for the dope to gel at the surface temperature of the drum or band during casting.
- the film production method of the present invention it is important to reduce the fluctuation of the residual solvent.
- it is necessary to volatilize the solvent sufficiently from casting to immediately before stretching. Specifically, after peeling off from the drum or band, it is dried with hot air in the process until stretching.
- the temperature of the hot air is preferably 120 ° C. to 180 ° C., more preferably 140 ° C. to 170 ° C.
- another functional material liquid is cast at the same time, and other functional layers (for example, an adhesive layer, a dye layer, an antistatic layer, an antihalation layer, a UV absorbing layer, a polarizing layer, etc.) are simultaneously formed.
- a film may be formed.
- the dope cast on the drum or belt is peeled off from the drum or belt after drying.
- the peeled material is called a web.
- the web peeled at the peeling position immediately before the drum or belt makes one round is conveyed by alternately passing through a group of rolls arranged in a staggered manner, or both ends of the peeled web are gripped by clips or the like. It is transported by a non-contact transport method.
- Drying is performed by a method of applying wind at a predetermined temperature to both sides of the web (film) being conveyed or a method using a heating means such as a microwave. Rapid drying can impair the planarity of the film formed. Therefore, in the initial stage of drying, it is preferable to dry at a temperature at which the solvent does not foam, and to dry at a high temperature after the drying proceeds.
- the film tends to shrink in the longitudinal direction or the width direction by evaporation of the solvent. Shrinkage increases with drying at higher temperatures. Drying while suppressing this shrinkage as much as possible is preferable for improving the flatness of the resulting film. From this point, for example, as shown in Japanese Patent Application Laid-Open No. 62-46625, a method in which all or part of the drying process is performed while holding the width at both ends of the web with clips or pins in the width direction. (Tenter method) is preferable.
- the drying temperature in the drying step is preferably 100 to 145 ° C.
- the drying temperature, the amount of drying air, and the drying time vary depending on the solvent used, but may be appropriately selected according to the type and combination of the solvents used.
- the production method of the present invention includes a step of drying a dope that has been cast in a single layer or multiple layers, peeling the dope from the support, and stretching the peeled web.
- the web peeled from the support is preferably stretched when the residual solvent amount in the web is less than 120% by mass.
- the amount of residual solvent in the web can be expressed by the following formula.
- M is the mass of the web at an arbitrary point
- N is the mass when the web of which M is measured is dried at 110 ° C. for 3 hours.
- the amount of residual solvent in the web is too large, the effect of stretching cannot be obtained, and if it is too small, stretching becomes extremely difficult and the web may break. More preferable ranges of the residual solvent amount in the web are 5% by mass to 50% by mass, and more preferably 8% by mass to 35% by mass. Further, if the stretching ratio is too small, a sufficient phase difference cannot be obtained, and if it is too large, stretching may become difficult and breakage may occur. Furthermore, even if the amount of residual solvent in the web varies within the range of 8 to 10% by mass, the retardation value of the stretched film hardly changes, so the amount of residual solvent in the web should be adjusted to 8 to 10% by mass. Is preferred.
- the optical properties (typically retardation) of the obtained stretched film are different even when stretched under the same conditions other than the residual solvent amount.
- the retardation film of the present invention because it contains a cellulose ester and a van der Waals volume of 500 ⁇ 3 or more 1000 ⁇ 3 or less is a compound, even residual solvent amount in the web is changed, the optical properties of the stretched film (retardation) Has a feature that it is difficult to fluctuate.
- Y / X is 1 nm. /% To 3 nm /% is preferable.
- the web produced by solution casting can be stretched without heating if the amount of residual solvent is in a specific range, but drying and stretching are preferred because the process can be shortened. That is, the stretching process may be performed with the solvent remaining, or the stretching process may be performed after drying. However, when the temperature of the web is too high, the plasticizer is volatilized, so the range of room temperature (15 ° C.) to 145 ° C. or less is preferable.
- the refractive indexes Nx, Ny, and Nz of the film can be easily adjusted to a desired range.
- the value of Nz becomes too large. In this case, it can be improved by suppressing the width shrinkage of the film or stretching in the width direction.
- a refractive index distribution may occur in the width direction.
- the distribution may occur when the tenter method is used.
- a shrinkage force is generated in the central portion of the film and the end portion is fixed, which is considered to be a so-called bowing phenomenon.
- the bowing phenomenon can be suppressed and the distribution of the phase difference in the width direction can be reduced.
- variation of the film obtained can be reduced by extending
- phase difference unevenness occurs.
- the film thickness variation of the optical film is preferably in the range of ⁇ 3%, and more preferably ⁇ 1%.
- a method of stretching the web in two axial directions perpendicular to each other is effective.
- the stretching ratios in biaxial directions perpendicular to each other are preferably in the range of 1.2 to 2.0 times and 0.7 to 1.0 times, respectively.
- stretching to 0.7 to 1.0 times means that the distance between clips and pins supporting the film is 0.7 to 1.0 times the distance before stretching. To do.
- the method for stretching the web is not particularly limited.
- These methods may be combined. That is, the film may be stretched in the transverse direction, longitudinally, or in both directions with respect to the film forming direction, and when stretched in both directions, simultaneous stretching or sequential stretching may be used. May be.
- the film after the stretching process may be stretched again.
- the re-stretching is preferable from the viewpoint of optical development properties, particularly expansion of the optical development area due to reduction of the Nz factor.
- the retardation film of the present invention is preferably used for a polarizing plate protective film because of its high optical expression.
- the polarizing plate is formed by laminating and laminating a protective film on at least one surface of the polarizer.
- a conventionally known polarizer can be used, for example, a film obtained by treating a hydrophilic polymer film such as a polyvinyl alcohol film with a dichroic dye such as iodine.
- the lamination of the retardation film of the present invention and the polarizer is not particularly limited, but can be performed with an adhesive made of an aqueous solution of a water-soluble polymer.
- the water-soluble polymer adhesive is preferably a completely saponified polyvinyl alcohol aqueous solution.
- the polarizing plate including the protective film for polarizing plate of the present invention has little deterioration under high temperature and high humidity conditions, and can maintain stable performance for a long time.
- a liquid crystal display device is a protective film for a polarizing plate (F1) / a polarizer / a protective film for a polarizing plate (F2) / a liquid crystal cell / a protective film for a polarizing plate (F3) / a polarizer 2 / for a polarizing plate. It has the structure of a protective film (F4).
- the liquid crystal cell carries a liquid crystal between two electrode substrates.
- the retardation film of the present invention and a polarizing plate using the retardation film can be used for liquid crystal display devices of liquid crystal cells in various display modes.
- liquid crystal cell types include TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), AFLC (Anti-ferroelectric Liquid Crystal), OCB (Optically Compensatory Bend), STN (Supper Twisted).
- Nematic Nematic
- VA Vertically Aligned
- HAN Hybrid Aligned Nematic
- the OCB mode liquid crystal cell is a liquid crystal display device using a bend alignment mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned in a substantially opposite direction (symmetrically) between the upper part and the lower part of the liquid crystal cell.
- OCB mode liquid crystal cells are disclosed in US Pat. Nos. 4,583,825 and 5,410,422. Since the rod-like liquid crystal molecules are aligned symmetrically between the upper part and the lower part of the liquid crystal cell, the bend alignment mode liquid crystal cell has a self-optical compensation function.
- the bend alignment mode liquid crystal display device has an advantage of high response speed.
- VA mode liquid crystal cell In a VA mode liquid crystal cell, rod-like liquid crystal molecules are aligned substantially vertically when no voltage is applied.
- the VA mode liquid crystal cell includes: (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2-). 176625 (in Japanese Patent Publication No. 176625), and (2) VA mode multi-domain (MVA mode) liquid crystal cell (SID97, Digest of ⁇ tech.
- any of the protective films F1 to F4 for polarizing plates in a liquid crystal display device can be used as the retardation film of the present invention. That is, in one aspect of the liquid crystal display device, the retardation film of the present invention is disposed between the liquid crystal cell and one polarizing plate, or two sheets are provided between the liquid crystal cell and both polarizing plates. Arrange the retardation film of the invention.
- the liquid crystal display device has, for example, 1) a protective film for polarizing plate / polarizer / protective film for polarizing plate / liquid crystal cell / film of the present invention / polarizer / protective film for polarizing plate, or 2 ) Protective film for polarizing plate / polarizer / film of the present invention / liquid crystal cell / film of the present invention / polarizer / protective film for polarizing plate.
- the liquid crystal cell of the liquid crystal display device may be a liquid crystal cell of TN type, VA type, OCB type or the like.
- the polarizing plate containing the retardation film of the present invention it is possible to provide a display device that is excellent in viewing angle and visibility with little coloring. Since the retardation film of the present invention has a relatively high retardation, it can be preferably combined with a VA liquid crystal cell.
- an optical compensation sheet made of the film of the present invention is used as a transparent protective film for a polarizing plate disposed between a liquid crystal cell and a polarizer.
- the above optical compensation sheet may be used only for the protective film (between the liquid crystal cell and the polarizer) of one polarizing plate, or two (between the liquid crystal cell and the polarizer) of both polarizing plates. You may use said optical compensation sheet for a sheet of protective film.
- the optical compensation sheet is used for only one polarizing plate, it is particularly preferable to use it as a protective film for the liquid crystal cell side of the backlight side polarizing plate of the liquid crystal cell.
- Protective films for polarizing plates other than the retardation film of the present invention can be ordinary cellulose acylate films.
- the thickness of a normal cellulose acylate film is preferably thinner than the thickness of the retardation film of the present invention.
- 40 to 80 ⁇ m is preferable.
- Examples of the usual cellulose acylate film include, but are not limited to, commercially available KC4UX2M (40 ⁇ m manufactured by Konica Capto), KC5UX (60 ⁇ m manufactured by Konica Capto), TD80 (80 ⁇ m manufactured by Fuji Film), and the like. .
- the cellulose acetate used in the examples is shown below.
- acetyl group substitution degree 1 indicates the acetyl group substitution degree of the low substitution degree component (cellulose acetate ⁇ ); “acetyl group substitution degree 2” indicates acetyl of the high substitution degree component (cellulose acetate ⁇ ). Indicates the degree of group substitution.
- the “content ratio” indicates the mass ratio of the low substitution component and the high substitution component (low substitution component / high substitution component).
- the horizontal axis indicates retention time (minutes), and the vertical axis indicates peak intensity ( ⁇ ).
- cellulose acetates A and B both have a minute peak in the region where the retention time is less than 5 minutes and a main peak in the region of 5 to 20 minutes.
- cellulose acetate D has a main peak in the region where the retention time is 5 to 20 minutes, but does not have a peak in the region less than 5 minutes.
- the peak in the region where the retention time is less than 5 minutes is derived from the low substitution component of cellulose acetate (cellulose acetate ⁇ having an acetyl group substitution degree of 2.1 or less); the retention time is 5 to 20 minutes. It is suggested that the peak in this region is derived from a component having a high degree of substitution of cellulose acetate (cellulose acetate ⁇ having an acetyl group substitution degree of 2.3 to 2.5). Further, the ratio of the peak area in the region where the retention time is less than 5 minutes and the peak area in the region where the retention time is 5 to 20 minutes is considered to correspond to the content ratio of the low substitution degree component and the high substitution degree component. .
- a main dope solution having the following composition was prepared.
- methylene chloride and ethanol were charged into a pressure dissolution tank.
- Cellulose acetate A was added to a pressurized dissolution tank containing a solvent while stirring. This was completely dissolved with heating and stirring. This was designated as Azumi Filter Paper No.
- the main dope solution was prepared by filtration using 244.
- the above materials were put into a sealed container and dissolved with stirring to prepare a dope.
- the dope was cast on a stainless steel support at a temperature of 35 ° C.
- an endless belt casting apparatus was used to uniformly cast the dope solution on a stainless steel belt support at a temperature of 33 ° C. and a width of 1500 mm.
- the temperature of the stainless steel belt was controlled at 30 ° C.
- the solvent was evaporated until the residual solvent amount in the film cast on the stainless steel belt support became 75%.
- the web was obtained by peeling from the stainless steel belt support with a peeling tension of 150 N / m.
- the peeled web was stretched 37% in the width direction using a tenter while applying heat at 155 ° C.
- the residual solvent at the start of stretching was 10%.
- the stretched film was dried while being transported through a drying zone by a number of rolls.
- the drying temperature was 140 ° C. and the transport tension was 100 N / m.
- a retardation film 101 having a dry film thickness of 40 ⁇ m was obtained.
- retardation films 102 to 108 and 110 to 115 were produced in substantially the same manner except that various components and residual melts during stretching were changed as shown in Table 2.
- retardation films 109 and 116 to 123 were produced as comparative examples.
- the retardation film 109 is used as a protective film. Therefore, in the production of the retardation film 109, various components were changed as shown in Table 2, and no stretching was performed.
- the plasticizer compounds A to D in Table 2 are as follows.
- the retardation Re hardly fluctuates I understand.
- the retardation films 101 and 102 are compared, the retardation Re varies by 4 nm (2 nm /%) when the residual solvent amount differs by 2%.
- the retardation films 116 and 117 are compared, the retardation Re varies by 10 nm (5 nm /%) when the residual solvent amount differs by 2%.
- ⁇ Preparation of hard coat film> 6.0 parts by mass of polyester urethane resin (manufactured by Toyobo Co., Ltd., trade name “Byron UR1350”, solid content concentration 33% (toluene / methyl ethyl ketone solvent 65/35)) and 30 parts by mass of pentaerythritol triacrylate 30 parts by mass of pentaerythritol tetraacrylate, 3.0 parts by mass of Irgacure 184 (manufactured by Ciba Japan, photopolymerization initiator), 1.0 part by mass of Irgacure 907 (manufactured by Ciba Japan, light Polymerization initiator), 2.0 parts by mass of polyether-modified polydimethylsiloxane (BYK-UV3510, manufactured by BYK Japan), 150 parts by mass of propylene glycol monomethyl ether, and 150 parts by mass of methyl ethyl ketone. The mixture was stir
- the obtained hard coat layer coating composition was filtered through a polypropylene filter having a pore size of 0.4 ⁇ m to prepare a hard coat layer coating solution.
- the hard coat layer coating solution was applied to the retardation film 109 (protective film) using a micro gravure coater and dried at 80 ° C. After drying, using a UV 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 of a dry thickness of 9 .mu.m. Then, it wound up and produced the roll-shaped hard coat film.
- 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 processed in the order of preliminary swelling, dyeing, uniaxial stretching by a wet method, fixing treatment, drying, and heat treatment to prepare a polarizing film. That is, the PVA film was immersed in water at a temperature of 30 ° C. for 30 seconds to be pre-swelled, 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.
- 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
- the boric acid concentration was 40 g / liter.
- 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.
- the PVA film was taken out, dried with hot air at a temperature of 40 ° C., and further heat-treated at a temperature of 100 ° C. for 5 minutes.
- the obtained polarizing film had an average thickness of 13 ⁇ m, a polarizing performance of a transmittance of 43.0%, a polarization degree of 99.5%, and a dichroic ratio of 40.1.
- a polarizing plate 201 was produced by bonding the polarizer, the retardation film 101, and the hard coat film according to the following steps 1 to 4.
- Step 1 The polarizer was immersed for 1 to 2 seconds in a storage tank of a polyvinyl alcohol adhesive solution having a solid content of 2% by mass.
- Step 2 The retardation film 101 and the hard coat film were alkali saponified under the following conditions.
- Water washing step Water 30 ° C 60 seconds
- Neutralization step 10 parts HCl 30 ° C 45 seconds
- Water washing step Water 30 ° C 60 seconds
- saponification treatment water washing, neutralization, water washing in this order And then dried at 100 ° C.
- 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 went so that a bubble might not enter.
- 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 retardation film 101 of 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. Formed. A peelable protective film was attached to the adhesive layer. This polarizing plate was cut (punched) into a size of 576 ⁇ 324 mm to produce a polarizing plate 201.
- Polarizers 202 to 222 were produced in the same manner as in the production of the viewing-side polarizing plate 201 except that the retardation film 101 was changed to the retardation films 102 to 108 and the retardation films 110 to 123, respectively.
- Polarizers 224 to 244 were produced in the same manner except that the retardation film 101 was changed to retardation films 102 to 108 and retardation films 110 to 123 in the production of the polarizer 223.
- Tables 3 and 4 show the evaluation results of the polarizing plates.
- ⁇ Production of Liquid Crystal Display Device 401> Remove the polarizing plate of the liquid crystal panel (VA mode liquid crystal panel) of the 40-inch display KDL-40V5 made by SONY, and make the polarizing plate 201 as the viewing side polarizing plate so that the hard coat layer is on the viewing side and the adhesive layer and the liquid crystal The cell glass was pasted. On the backlight side, a polarizing plate 223 was bonded to the liquid crystal cell glass using an acrylic adhesive having a thickness of 25 ⁇ m. Thus, the liquid crystal panel 301 was produced. Next, the liquid crystal panel 301 was set on a liquid crystal television, and a liquid crystal display device 401 was manufactured.
- VA mode liquid crystal panel the 40-inch display KDL-40V5 made by SONY
- the polarizing plate of the present invention prevents deformation failure when stored under high temperature and high humidity, and stripes and visibility (clearness) when used in a liquid crystal display device. Excellent performance in both.
- the retardation film of the present invention has a small fluctuation range of the retardation value with respect to the change of the residual solvent amount of the film at the time of stretching, it is necessary to precisely control the residual solvent amount of the film before stretching in the production process. This is advantageous in manufacturing.
- the adhesiveness with a hydrophilic film can be made high by carrying out the alkali treatment of the surface of the said cellulose acetate film.
- the cellulose acetate film is suitably used as a polarizing plate as a retardation film in combination with a polarizer.
Landscapes
- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Nonlinear Science (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mathematical Physics (AREA)
- Materials Engineering (AREA)
- Polarising Elements (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Manufacture Of Macromolecular Shaped Articles (AREA)
Abstract
Description
延伸開始時の残留溶媒量をX(%)上昇させたときのReの低下量をY(nm)としたときに、Y/Xが1nm/%~3nm/%である、[1]または[2]に記載の位相差フィルム。
本発明の位相差フィルム(以下、本発明のフィルムともいう)は、アセチル置換度2.1以下であるセルロースアセテートαと、アセチル置換度2.3~2.5であるセルロースアセテートβと、ファンデルワールス体積500Å3以上1000Å3以下の化合物とを含み、かつ延伸されている。
本発明の位相差フィルムに含まれるセルロールアセテートαおよびセルロースアセテートβの原料となるセルロースの例には、綿花リンタや木材パルプ(広葉樹パルプ,針葉樹パルプ)などがある。何れの原料セルロースから得られるセルロースアセテートを使用してもよく、場合により混合して使用してもよい。これらの原料セルロースについての詳細な記載は、例えば、丸澤、宇田著、「プラスチック材料講座(17)繊維素系樹脂」日刊工業新聞社(1970年発行)や発明協会公開技報公技番号2001-1745号(7頁~8頁)に記載のセルロースを用いることができる。
本発明の位相差フィルムには、ファンデルワールス体積500Å3以上1000Å3以下の化合物が含まれる。
本発明の位相差フィルムに含まれる可塑剤の例には、フタル酸エステル、リン酸エステル、多価アルコールエステルなどが含まれる。可塑剤の添加量としては、セルロースエステルに対して、0.5~30質量%含むことが好ましく、特には、5~20質量%含むことが好ましい。
本発明の位相差フィルムには、公知の劣化(酸化)防止剤が含有されうる。劣化(酸化)防止剤の例には、2,6-ジ-tert-ブチル-4-メチルフェノール、4,4'-チオビス-(6-tert-ブチル-3-メチルフェノール)、1,1'-ビス(4-ヒドロキシフェニル)シクロヘキサン、2,2'-メチレンビス(4-エチル-6-tert-ブチルフェノール)、2,5-ジ-tert-ブチルヒドロキノン、ペンタエリスリチル-テトラキス[3-(3,5-ジ-tert-ブチル-4-ヒドロキシフェニル)プロピオネート]などの、フェノール系酸化防止剤あるいはヒドロキノン系酸化防止剤が含まれる。
本発明の位相差フィルムには、偏光板または液晶等の劣化防止の観点から、紫外線吸収剤が含まれることが好ましい。紫外線吸収剤としては、波長370nm以下の紫外線の吸収能に優れ、かつ良好な液晶表示性の観点から、波長400nm以上の可視光の吸収が少ないものが好ましく用いられる。
本発明の位相差フィルムには、剥離性を高める観点から、剥離促進剤が含まれることが好ましい。剥離促進剤の含有量は、例えば、0.001~1質量%であり、0.005~0.5質量%であることが好ましく、0.01~0.3質量%であることがより好ましい。含有量が1質量%以下であれば、剥離剤のフィルムからの分離等が発生し難いため好ましい。0.005質量%以上であれば所望の剥離低減効果を得ることができるため好ましい。
本発明の位相差フィルムには、ハンドリングされる際に、傷ついたり搬送性が悪化することを防止するために、微粒子が添加されていてもよい。それらは、マット剤、ブロッキング防止剤あるいはキシミ防止剤と称されて、従来から利用されている。それらは、前述の機能を呈する素材であれば特に限定されず、無機化合物のマット剤であっても、有機化合物のマット剤であってもよい。
本発明の位相差フィルムのレターデーション(面内レターデーションReおよび膜厚方向のレターデーションRth)は、液晶セルおよび光学フィルムの設計により適宜選択される。一般的に、面内レターデーションReが25nm≦|Re|≦75nmであり、かつ、膜厚方向のレターデーションRthが50nm≦|Rth|≦250nmであることが好ましい。Reは40nm≦|Re|≦75nmであることがより好ましく、45nm≦|Re|≦70nmであることが特に好ましい。前記Rthは70nm≦|Rth|≦240nmであることがより好ましく、90nm≦|Rth|≦230nmであることが特に好ましい。
本発明の位相差フィルムは、下記式(7)で表されるNZファクターが、7以下であることが好ましく、5.5以下であることがより好ましく、4.5以下であることが特に好ましい。ただし一般的に、Nzファクターは液晶セルおよび光学フィルム等の設計により適宜選択される。
本発明の位相差フィルムのヘイズは1%未満であることが好ましく、0.5%未満であることがより好ましい。ヘイズを1%未満とすることにより、フィルムの透明性がより高くなり、光学フィルムとしてより用いやすくなるという利点がある。
本発明の位相差フィルムの平衡含水率(25℃、相対湿度60%)は4%以下であることが好ましく、3%以下であることがより好ましい。平均含水率を4%以下とすることにより、湿度変化に対応しやすく、光学特性や寸法がより変化しにくく好ましい。
本発明の位相差フィルムの平均膜厚は、30~100μmであることが好ましく、30~80μmであることがより好ましく、30~70μmであることがさらに好ましい。30μm以上とすることにより、ウェブ状のフィルムを作製する際のハンドリング性が向上し好ましい。また、100μm以下とすることにより、湿度変化に対応しやすく、光学特性を維持しやすい。
本発明の位相差フィルムのフィルム幅は、700~3000mmであることが好ましく、1000~2800mmであることがより好ましく、1500~2500mmであることが特に好ましい。
本発明の位相差フィルムの製造方法(以下、本発明の製造方法とも言う)は、前記置換度を満たすセルロースアセテートと、前記ファンデルワールス体積を満たす化合物とを含むドープを、支持体上に流延する工程と、該流延したドープを乾燥させて支持体から剥離する工程と、剥離後のフィルムを延伸する工程とを含む。詳しくは、本発明の位相差フィルムは、セルロースアセテートを有機溶媒に溶解した溶液(ドープ)を、ソルベントキャスト法を用いて製膜して製造される。
ドープの有機溶媒は、1種単独であっても、2種類以上の有機溶媒の混合溶媒であってもよい。
ドープをドラムまたはバンド上に流延し、溶媒を蒸発させてフィルムを成膜する。流延されるドープは、固形分量が18~35質量%となるように濃度を調整することが好ましい。ドラムまたはバンドの表面は、鏡面状態に仕上げておくことが好ましい。ソルベントキャスト法における流延および乾燥方法については、米国特許第2336310号、同2367603号、同2492078号、同2492977号、同2492978号、同2607704号、同2739069号、同2739070号、英国特許第640731号、同736892号の各明細書、特公昭45-4554号、同49-5614号、特開昭60-176834号、同60-203430号、同62-115035号の各公報に記載がある。
ドラムやベルトに流延されたドープは、乾燥後、ドラムやベルトから剥離される。その剥離物をウェブという。ドラムやベルトが1周する直前の剥離位置で剥離されたウェブは、千鳥状に配置されたロ-ル群に交互に通して搬送する方法や剥離されたウェブの両端をクリップ等で把持させて非接触的に搬送する方法などにより搬送される。
本発明の製造方法は、一層流延または多層流延したドープを乾燥させて支持体から剥離し、剥離後のウェブを延伸する工程を含む。支持体から剥離したウェブを、ウェブ中の残留溶媒量が120質量%未満の時に延伸することが好ましい。
本発明の位相差フィルムは、光学発現性が高いため、偏光板保護フィルムに好ましく用いられる。偏光板は、偏光子の少なくとも一方の面に保護フィルムを貼り合わせ積層することによって形成される。偏光子は従来から公知のものを用いることができ、例えば、ポリビニルアルコールフィルムなどの親水性ポリマーフィルムを、沃素のような二色性染料で処理して延伸したフィルムである。
液晶表示装置は、一般的に、偏光板用保護フィルム(F1)/偏光子1/偏光板用保護フィルム(F2)/液晶セル/偏光板用保護フィルム(F3)/偏光子2/偏光板用保護フィルム(F4)の構成を有する。液晶セルは、二枚の電極基板の間に液晶を担持している。
装置:蒸発光散乱検出システム(島津製作所製)
溶離液:(A)クロロホルム/メタノール(9/1、体積比)
(B)メタノール/水(8/1、体積比)
(A/B)20/80(0分)-100/0(28分)
流速:0.7ml/分
検出器:エバポレイティブ光散乱検出器
エバポレイション温度75℃
ネブライザ温度60℃
窒素圧力30psi
カラム温度30℃
注入量:20μl
試料溶解:溶離液(A)で0.1%に調整
〈微粒子分散液1〉
11質量部の微粒子(アエロジル R972V 日本アエロジル(株)製)と、89質量部のエタノールとを、ディゾルバーで50分間攪拌混合した後、マントンゴーリンで分散を行った。
溶解タンク内で攪拌されている99質量部のメチレンクロライドに、5質量部の微粒子分散液1を、ゆっくりと添加した。さらに、二次粒子の粒径が所定の大きさとなるようにアトライターにて分散を行った。これを日本精線(株)製のファインメットNFで濾過し、微粒子添加液1を調製した。
メチレンクロライド:340質量部
エタノール:64質量部
セルロースアセテートA:100質量部
化合物28(ファンデルワールス体積:848):6.0質量部
化合物A:2.0質量部
化合物D:2.0質量部
微粒子添加液1:1質量部(化合物A:トリメチロールプロパントリベンゾエート、化合物D:エチルフタリルエチルグリコレート)
化合物A:トリメチロールプロパントリベンゾエート
化合物B:トリフェニルフォスフェート
化合物C:ビスフェニルビフェニルフォスフェート
化合物D:エチルフタリルエチルグリコレート
(紫外線吸収剤)
チヌビン928(チバ・ジャパン(株)製)
KOBRA-21ADH(王子計測機器(株))を用いて、23℃、55%RHの環境下で、位相差フィルム101~123の複屈折位相差(Re)を、波長が590nmで求めた。得られた結果を表2に示した。
6.0質量部のポリエステルウレタン樹脂(東洋紡績(株)製、商品名「バイロンUR1350」、固形分濃度33%(トルエン/メチルエチルケトン溶媒=65/35))と、30質量部のペンタエリスリトールトリアクリレートと、30質量部のペンタエリスリトールテトラアクリレートと、3.0質量部のイルガキュア184(チバ・ジャパン社製、光重合開始剤)と、1.0質量部のイルガキュア907(チバ・ジャパン社製、光重合開始剤)と、2.0質量部のポリエーテル変性ポリジメチルシロキサン(BYK-UV3510、ビックケミージャパン社製)と、150質量部のプロピレングリコールモノメチルエーテルと、150質量部のメチルエチルケトンとの混合物を攪拌して、ハードコート層塗布組成物とした。6.0質量部のポリエステルウレタン樹脂に含まれるポリエステルウレタン樹脂量は2.0質量部である。
(a)偏光子の作製
けん化度99.95モル%、重合度2400のポリビニルアルコール(以下、PVAと略記する)100質量部に、グリセリン10質量部、および水170質量部を含浸させたものを溶融混練し、脱泡後、Tダイから金属ロール上に溶融押出し、製膜した。その後、乾燥・熱処理して、PVAフィルムを得た。
下記工程1~4に従って、偏光子と、位相差フィルム101と、ハードコートフィルムを貼り合わせて偏光板201を作製した。
(アルカリ鹸化処理)
ケン化工程 1.5M-KOH 50℃ 45秒
水洗工程 水 30℃ 60秒
中和工程 10質量部HCl 30℃ 45秒
水洗工程 水 30℃ 60秒
ケン化処理後、水洗、中和、水洗の順に行い、次いで100℃で乾燥。
視認側偏光板201の作製において、位相差フィルム101を位相差フィルム102~108、位相差フィルム110~123に、それぞれ変更した以外は同様にして偏光板202~222を作製した。
視認側偏光板の作製と同様にして、偏光子と、位相差フィルム101と、位相差フィルム109とを貼り合わせて偏光板223を作製した。
偏光板223の作製において、位相差フィルム101を位相差フィルム102~108、位相差フィルム110~123に、それぞれ変更した以外は同様にして偏光板224~244を作製した。
偏光板201~244の耐久試験(60℃、90%RHの条件で100時間放置した後、23℃、55%RHに戻した)を実施した偏光板を位相差フィルム109(保護フィルム)側から観察して、変形故障の状態を以下の基準で観察した。
◎:変形故障が全くみられない
○:僅かな部分で変形故障がみられるが、実用上問題なし
△:部分的に変形故障がみられる。実用上問題あり
×:部分的な変形故障が、遠くから見てもはっきりと発生している事がみえる。
偏光板201~244の位相差フィルムを有する側の表面に、カッターナイフで碁盤目状に縦11本、横11本の切り込みを入れて、合計100個の正方形の升目を刻んだ。その表面に、日東電工(株)製のポリエステル粘着テープ" No.31B" を圧着して、さらに粘着テープを剥離した。位相差フィルムの偏光子からの剥がれの有無を目視で観察し、下記の4段階評価を行った。
◎:100個の升目中に剥がれが全く認められなかったもの
○:100個の升目中に剥がれが認められたものが2升以内のもの
△:100個の升目中に剥がれが認められたものが3~10升のもの
×:100個の升目中に剥がれが認められたものが10升を超えたもの
SONY製40型ディスプレイKDL-40V5の液晶パネル(VAモードの液晶パネル)の偏光板を剥がし、視認側の偏光板として偏光板201をハードコート層が視認側となるようにして、粘着層と液晶セルガラスとを貼合した。また、バックライト側には、偏光板223を、厚さ25μmのアクリル系粘着剤を用いて液晶セルガラスに貼合した。このようにして、液晶パネル301を作製した。次に液晶パネル301を液晶テレビにセットし、液晶表示装置401を作製した。
液晶表示装置401の作製において、表5に示すように、視認側偏光板201を202~222に、バックライト側偏光板223を224~244それぞれ変更した以外は同様にして液晶表示装置402~422を作製した。
上記作製した各液晶表示装置401~422について、熱による劣化を見るために60℃の条件で300時間処理した後、23℃、55%RHに戻した。その後、電源を入れてバックライトを点灯させてから2時間後の黒表示時のスジを目視により下記基準で評価した。○以上の評価であれば、実用上問題ない。
◎:スジがまったくない。
○:中央に弱いスジが存在する。
△:中央から端部にかけて弱いスジが存在する。
×:全面に強いスジが存在する。
上記作製した各液晶表示装置について、60℃、90%RHの条件で100時間放置した後、23℃、55%RHに戻した。その後、表示装置の表面を目視で観察し下記の基準による評価をした。
◎:表面に波打ち状のムラは全く認められない。
○:表面にわずかに波打ち状のムラが認められる。
△:表面に細かい波打ち状のムラがやや認められる。
×:表面に細かい波打ち状のムラが認められる。
Claims (8)
- アセチル置換度2.1以下であるセルロースアセテートαと、アセチル置換度2.3~2.5であるセルロースアセテートβと、前記セルロースアセテートαと前記セルロースアセテートβの合計に対して5~10質量%のファンデルワールス体積500Å3以上1000Å3以下である化合物とを含有し、
延伸されている位相差フィルム。 - 前記ファンデルワールス体積500Å3以上1000Å3以下の化合物が、下記一般式(I)~(V)のいずれかで表される化合物である、請求項1記載の位相差フィルム。
- 測定波長590nmにおける面内方向のレターデーションReが25nm≦|Re|≦75nmであり、かつ、
延伸開始時の残留溶媒量をX(%)上昇させたときのReの低下量をY(nm)としたときに、Y/Xが1nm/%~3nm/%である、請求項1に記載の位相差フィルム。 - 測定波長590nmにおける面内方向のレターデーションReが25nm≦|Re|≦75nmであり、かつ、
延伸開始時の残留溶媒量をX(%)上昇させたときのReの低下量をY(nm)としたときに、Y/Xが1nm/%~3nm/%である、請求項2に記載の位相差フィルム。 - フィルム幅が700~3000mmである、請求項1に記載の位相差フィルム。
- フィルム幅が700~3000mmである、請求項2に記載の位相差フィルム。
- 請求項1~6のいずれか一項に記載の位相差フィルムを少なくとも1枚用いたことを特徴とする偏光板。
- 請求項1~6のいずれか一項に記載の位相差フィルムを少なくとも1枚用いたことを特徴とする液晶表示装置。
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/354,213 US9581861B2 (en) | 2011-11-01 | 2012-11-01 | Phase difference film, polarizing plate, and liquid crystal display device |
JP2013541633A JP6024666B2 (ja) | 2011-11-01 | 2012-11-01 | 位相差フィルム、偏光板および液晶表示装置 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2011-240155 | 2011-11-01 | ||
JP2011240155 | 2011-11-01 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2013065307A1 true WO2013065307A1 (ja) | 2013-05-10 |
Family
ID=48191680
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2012/007004 WO2013065307A1 (ja) | 2011-11-01 | 2012-11-01 | 位相差フィルム、偏光板および液晶表示装置 |
Country Status (3)
Country | Link |
---|---|
US (1) | US9581861B2 (ja) |
JP (1) | JP6024666B2 (ja) |
WO (1) | WO2013065307A1 (ja) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004177642A (ja) * | 2002-11-27 | 2004-06-24 | Konica Minolta Holdings Inc | 位相差フィルムとその製造方法、光学補償フィルム、偏光板及び液晶表示装置 |
JP2006323152A (ja) * | 2005-05-19 | 2006-11-30 | Fujifilm Holdings Corp | 透明フィルム、光学補償フィルム、偏光板及び液晶表示装置 |
JP2007131681A (ja) * | 2005-11-08 | 2007-05-31 | Kaneka Corp | 高分子フィルム、位相差フィルム、位相差フィルムの製造方法、位相差フィルムを使用した光学補償偏光板 |
JP2012002981A (ja) * | 2010-06-16 | 2012-01-05 | Konica Minolta Opto Inc | 偏光板、液晶表示装置及びセルロースアセテートフィルムの製造方法 |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3466250B2 (ja) | 1993-11-26 | 2003-11-10 | 大日本印刷株式会社 | 耐擦傷性、耐薬品性を有するプラスチックフィルム、その製造方法、及び偏光板 |
JP3421443B2 (ja) | 1994-09-29 | 2003-06-30 | 富士写真フイルム株式会社 | 楕円偏光板および液晶表示装置 |
JP2001166146A (ja) | 1999-09-24 | 2001-06-22 | Konica Corp | 視野角拡大用フィルム、光学フィルム、偏光板用保護フィルム、液晶表示装置の製造方法、液晶パネル用プラスチック基板 |
JP3628933B2 (ja) | 2000-04-12 | 2005-03-16 | 積水化学工業株式会社 | 位相差補償フィルムの製造方法 |
JP2001188130A (ja) | 2000-11-22 | 2001-07-10 | Konica Corp | プラスチックフィルム、偏光板用保護フィルム、偏光板 |
JP2003232920A (ja) * | 2002-02-07 | 2003-08-22 | Konica Corp | 光学フィルム及びその製造方法 |
JP5470672B2 (ja) * | 2004-12-09 | 2014-04-16 | コニカミノルタ株式会社 | セルロースエステルフィルムの製造方法 |
US8697201B2 (en) * | 2005-03-31 | 2014-04-15 | Kaneka Corporation | Retardation film and production method thereof |
JP4622698B2 (ja) * | 2005-06-22 | 2011-02-02 | コニカミノルタオプト株式会社 | 位相差板、偏光板及び液晶表示装置 |
JP4618104B2 (ja) * | 2005-11-11 | 2011-01-26 | パナソニック株式会社 | 加熱調理器 |
JP2009139812A (ja) * | 2007-12-10 | 2009-06-25 | Konica Minolta Opto Inc | ロール状の位相差フィルム、ロール状の位相差フィルムの製造方法および円偏光板 |
JP2009265598A (ja) * | 2008-03-31 | 2009-11-12 | Fujifilm Corp | 偏光板用保護フィルム |
JP5531929B2 (ja) * | 2010-11-24 | 2014-06-25 | コニカミノルタ株式会社 | 光散乱性フィルム、光散乱性偏光板、及び液晶表示装置 |
JP5857771B2 (ja) * | 2012-02-08 | 2016-02-10 | コニカミノルタ株式会社 | 導電性フィルム及びタッチパネル |
-
2012
- 2012-11-01 US US14/354,213 patent/US9581861B2/en active Active
- 2012-11-01 WO PCT/JP2012/007004 patent/WO2013065307A1/ja active Application Filing
- 2012-11-01 JP JP2013541633A patent/JP6024666B2/ja active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004177642A (ja) * | 2002-11-27 | 2004-06-24 | Konica Minolta Holdings Inc | 位相差フィルムとその製造方法、光学補償フィルム、偏光板及び液晶表示装置 |
JP2006323152A (ja) * | 2005-05-19 | 2006-11-30 | Fujifilm Holdings Corp | 透明フィルム、光学補償フィルム、偏光板及び液晶表示装置 |
JP2007131681A (ja) * | 2005-11-08 | 2007-05-31 | Kaneka Corp | 高分子フィルム、位相差フィルム、位相差フィルムの製造方法、位相差フィルムを使用した光学補償偏光板 |
JP2012002981A (ja) * | 2010-06-16 | 2012-01-05 | Konica Minolta Opto Inc | 偏光板、液晶表示装置及びセルロースアセテートフィルムの製造方法 |
Also Published As
Publication number | Publication date |
---|---|
JPWO2013065307A1 (ja) | 2015-04-02 |
JP6024666B2 (ja) | 2016-11-16 |
US9581861B2 (en) | 2017-02-28 |
US20140326930A1 (en) | 2014-11-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5329088B2 (ja) | セルロースエステルフィルム、偏光板及び液晶表示装置 | |
WO2013164868A1 (ja) | 位相差フィルム、偏光板の製造方法および液晶表示装置 | |
JP6138689B2 (ja) | セルロースアシレートフィルム、偏光板及び液晶表示装置 | |
KR20100138901A (ko) | 셀룰로오스에스테르 필름, 그것을 사용한 위상차 필름, 편광판 및 액정 표시 장치 | |
JP2007003679A (ja) | 位相差板、偏光板及び液晶表示装置 | |
WO2011108350A1 (ja) | 偏光板の製造方法、それを用いた偏光板、及び液晶表示装置 | |
JP5156067B2 (ja) | セルロースアシレートフィルム | |
JP5501144B2 (ja) | セルロースエステルフィルム、偏光板、及び液晶表示装置 | |
JP2013254190A (ja) | 光学フィルム、偏光板、及び液晶表示装置 | |
JPWO2007125797A1 (ja) | 偏光板用光学補償樹脂フィルム、光学補償樹脂フィルムの製造方法、偏光板及び液晶表示装置 | |
JP2006154384A (ja) | 位相差フィルム、及びそれを用いた偏光板、表示装置 | |
JP5384314B2 (ja) | セルロースアシレートフィルム、偏光板及び液晶表示装置 | |
WO2012014571A1 (ja) | セルロースアセテートフィルム、セルロースアセテートフィルムの製造方法、偏光板及び液晶表示装置とその製造方法 | |
JP2009249386A (ja) | セルロースアシレートフィルム、偏光板、液晶表示装置 | |
JP2013075401A (ja) | セルロースアシレート積層フィルムとその製造方法、偏光板および液晶表示装置 | |
JP5156133B2 (ja) | セルロースアシレートフィルムの製造方法 | |
US20130068133A1 (en) | Cellulose ester film, polarizing plate and liquid crystal display device | |
JP2010215879A (ja) | セルロースエステルフィルム及びそれを用いた偏光板並びに液晶表示装置 | |
JP2014071202A (ja) | 偏光板および液晶表示装置 | |
JP6140389B2 (ja) | セルロースアシレートフィルム、これを用いた偏光板および液晶表示装置 | |
JP6024666B2 (ja) | 位相差フィルム、偏光板および液晶表示装置 | |
JP5912073B2 (ja) | セルロースアシレートフィルム、偏光板及び液晶表示装置 | |
JP4587264B2 (ja) | 光学補償フィルム及びそれを用いた偏光板、液晶表示装置 | |
JP2013064974A (ja) | セルロースアシレートフィルムとその製造方法、偏光板、液晶表示装置 | |
JP2007039505A (ja) | セルロースアシレートフィルム並びにそれを用いた偏光板及び液晶表示装置 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12844732 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2013541633 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14354213 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 12844732 Country of ref document: EP Kind code of ref document: A1 |