WO2015146599A1 - 位相差フィルムおよび、それを用いた偏光板、表示装置 - Google Patents
位相差フィルムおよび、それを用いた偏光板、表示装置 Download PDFInfo
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- WO2015146599A1 WO2015146599A1 PCT/JP2015/057233 JP2015057233W WO2015146599A1 WO 2015146599 A1 WO2015146599 A1 WO 2015146599A1 JP 2015057233 W JP2015057233 W JP 2015057233W WO 2015146599 A1 WO2015146599 A1 WO 2015146599A1
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- nitrogen
- retardation film
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/16—Nitrogen-containing compounds
- C08K5/34—Heterocyclic compounds having nitrogen in the ring
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D11/00—Producing optical elements, e.g. lenses or prisms
- B29D11/00634—Production of filters
- B29D11/00644—Production of filters polarizing
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D11/00—Producing optical elements, e.g. lenses or prisms
- B29D11/0074—Production of other optical elements not provided for in B29D11/00009- B29D11/0073
- B29D11/00788—Producing optical films
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- 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
- 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
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- 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
-
- 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
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- 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
- G02F1/133635—Multifunctional compensators
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/30—Polarising elements
- G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
- G02B5/3033—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid
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- 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
- G02F2201/00—Constructional arrangements not provided for in groups G02F1/00 - G02F7/00
- G02F2201/50—Protective arrangements
Definitions
- the present invention relates to a retardation film, a polarizing plate, and a display device. More specifically, the present invention relates to a retardation film in which fluctuations in retardation in a moist heat environment are suppressed, and a polarizing plate and a display device that are excellent in wet heat resistance.
- a liquid crystal display device is composed of a liquid crystal cell in which a transparent electrode, a liquid crystal layer, a color filter, etc. are sandwiched between glass plates, and two polarizing plates provided on both sides thereof.
- a polarizer also referred to as a polarizing film or a polarizing film
- a protective film As the polarizing plate protective film, a film having high transparency and capable of easily ensuring adhesion with polyvinyl alcohol used in a polarizer has been widely used.
- the retardation film has high moisture permeability, it can easily cause fluctuations in the retardation value (retardation value) of the retardation film by allowing moisture to penetrate to the inside. As a result, the color of the liquid crystal display device There was a problem of unevenness.
- Examples of a method for improving the retardation value fluctuation (retardation fluctuation) of the retardation film include a method for reducing the thickness of the retardation film and a method for adding a large amount of additives to control moisture permeability. .
- a method for reducing the thickness of the retardation film and a method for adding a large amount of additives to control moisture permeability.
- the retardation value becomes small, so a compound having a high retardation value increasing ability (retardation expression) is required.
- a retardation increasing agent in which the retardation fluctuation of the retardation film due to humidity is small for example, a pyrimidine-based compound (Japanese Patent Laid-Open No. 2012-214683) and a triazine-based compound (for example, Japanese Patent Laid-Open No. 2003-344655) are proposed.
- a pyrimidine-based compound Japanese Patent Laid-Open No. 2012-214683
- a triazine-based compound for example, Japanese Patent Laid-Open No. 2003-344655
- a liquid crystal compound having a larger molecular weight is further added to improve the retardation development (Japanese Patent Application Laid-Open No. 2007-119737).
- the compounds described in Japanese Patent Application Laid-Open No. 2012-214683 or Japanese Patent Application Laid-Open No. 2003-344655 have a problem that molecular thermal motion is large in a moist heat environment and phase difference variation is large.
- the compounds described in JP2012-214683A or JP2003-344655A have insufficient retardation.
- in order to enhance the retardation development even if a compound having two or more aromatic rings as in JP-A-2007-119737 is added, sufficient retardation development cannot be obtained.
- the addition amount of such a compound is increased, the retardation film, the polarizing plate, and the liquid crystal display device using the retardation film have a problem that the heat and humidity resistance is further deteriorated.
- the present invention has been made in view of the above problems, and a retardation film capable of suppressing phase fluctuations under a wet and heat environment while maintaining high retardation development, and a polarizing plate and a display device using the same The purpose is to provide.
- the present inventor conducted intensive research to solve the above problems. As a result, by mixing the nitrogen-containing compound (B) represented by the following general formula (2) together with the nitrogen-containing compound (A) represented by the following general formula (1) as a phase difference increasing agent, a high retardation is obtained.
- the inventors have found that it is possible to suppress phase difference fluctuations in a moist heat environment while maintaining expression, and have completed the present invention.
- Ar is each independently a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted nitrogen-containing aromatic heterocyclic ring, and X 2 and Y 2 are each independently Represents a substituted or unsubstituted nitrogen-containing aromatic heterocycle)
- Ar is each independently a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted nitrogen-containing aromatic heterocyclic ring, and X 3 , Y 3 , and Z 3 are Each independently represents a substituted or unsubstituted nitrogen-containing aromatic heterocycle)
- phase difference film manufacturing apparatus Dope preparation process, casting process, and drying process of a solution casting film forming method
- 1 is a melting pot
- 2, 5, 11, and 14 are liquid feed pumps
- 3, 6, 12, and 15 are filters
- 4, 13 is a stock tank
- 8, 16 are conduits
- 10 is an additive preparation.
- Kettle 20 merging pipe, 21 mixer, 30 die, 31 metal support, 32 web, 33 peeling position, 34 tenter device, 35 roller drying device, 36 roll, 37 winder
- Reference numeral 41 is a charging tank
- 42 is a stock tank
- 43 is a pump
- 44 is a filter.
- FIG. 101A and 101B are polarizing plates
- 102 is a protective film
- 103A and 103B are active energy ray-curable adhesives
- 104 is a polarizer
- 105 is a retardation film
- 106 is a functional layer
- 107 is a liquid crystal cell
- 108 Represents a liquid crystal display device.
- the present invention is represented by the following general formula (1):
- Ar is each independently a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted nitrogen-containing aromatic heterocyclic ring, and X 2 and Y 2 are each independently Represents a substituted or unsubstituted nitrogen-containing aromatic heterocycle)
- Ar is each independently a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted nitrogen-containing aromatic heterocyclic ring, and X 3 , Y 3 , and Z 3 are Each independently represents a substituted or unsubstituted nitrogen-containing aromatic heterocycle
- the retardation film of the present invention includes a retardation increasing agent containing a nitrogen-containing compound (A) and a nitrogen-containing compound (B) represented by general formulas (1) and (2), respectively.
- the retardation film having such a structure can achieve both high retardation development and high wet heat durability.
- the mechanism for exerting the above-described effects by the configuration of the present invention is presumed as follows.
- the present invention is not limited to the following mechanism. That is, first, in the state of normal temperature and humidity before being placed in a humid heat environment, the retardation increasing agent containing the nitrogen-containing compound (A) and the nitrogen-containing compound (B) is used in the retardation film.
- the molecules are oriented with the long axis of the molecule directed in a direction parallel to the stretching direction. At this time, due to the orientation described above, the nitrogen-containing compound (A) and the nitrogen-containing compound (B) each express a phase difference.
- each of the nitrogen-containing compound (A) and the nitrogen-containing compound (B) has a different amount of retardation per molecule and a disordered orientation in a wet and heat environment.
- the nitrogen-containing compound (B) having a large molecular weight has an excellent effect of suppressing fluctuations in optical properties due to strong interaction with a base resin such as cellulose ester.
- the nitrogen-containing compound (A) having a small molecular weight is excellent in compatibility with a base resin such as cellulose ester. Then, since the nitrogen-containing compound (A) interacts with the nitrogen-containing compound (B), which has a strong interaction with the base resin, by hydrogen bonding or the like, disorder of its orientation is suppressed.
- the nitrogen-containing compound (B) when the nitrogen-containing compound (B) is also used in combination with the nitrogen-containing compound (A) having good compatibility with the base resin such as cellulose, it becomes easy to become familiar with the base resin, and the phase difference fluctuation is further suppressed.
- the influence which both nitrogen-containing compounds receive in a wet heat environment mutually cancels by using together two types of nitrogen-containing compounds.
- the retardation fluctuation when viewed as a retardation film is improved, and the durability is higher than when the nitrogen-containing compound (A) and the nitrogen-containing compound (B) are each used alone as a retardation increasing agent.
- a retardation film is provided.
- the retardation film according to the present invention is characterized by including a retardation increasing agent including the nitrogen-containing compound (A) and the nitrogen-containing compound (B) represented by the general formulas (1) and (2).
- the retardation film according to the present invention includes the retardation increasing agent according to the present invention, so that the retardation film has high retardation and can suppress the retardation fluctuation in a wet heat environment.
- the retardation value has a small fluctuation.
- the retardation fluctuation is small in terms of preventing color unevenness.
- R O variation rate in order to further reduce the color unevenness resulting from the phase difference fluctuation due to humidity, preferably satisfies 4% ⁇ , more preferably ⁇ 3%, further Preferably, it is ⁇ 2.5%.
- the Rt variation rate is preferably within ⁇ 5%, more preferably within ⁇ 4%, and further preferably within ⁇ 3.5%.
- the retardation film according to the present invention preferably has a film thickness of 15 ⁇ m or more and 35 ⁇ m or less. If it is 15 ⁇ m or more, uniform film formation is possible, and color unevenness can be prevented when the area is large. A sufficient phase difference can be obtained. On the other hand, when the thickness is 35 ⁇ m or less, it is possible to suppress the occurrence of color unevenness when the display device is formed by increasing the absolute value of the amount of moisture absorbed. It is preferably in the range of 15 to 35 ⁇ m, more preferably 20 to 35 ⁇ m from the viewpoint of homogeneous film formation, Ro, and Rt humidity fluctuation.
- the film thickness can be controlled within the desired range by adjusting the thickness of the dope or melt to be cast during film formation and / or stretching conditions.
- the retardation film according to the present invention preferably has a thickness variation of 0 to 4 ⁇ m in both the width direction and the longitudinal direction. In such a case, even if the retardation film has a large area, the retardation variation in the retardation film surface is suppressed, and color unevenness can be prevented.
- the film thickness variation is preferably 0 to 2.5 ⁇ m, more preferably 0 to 1.5 ⁇ m.
- the film thickness of the retardation film can be measured using a film thickness meter such as a micrometer. Specifically, the film thickness ( ⁇ m) is measured at 100 or more points at 10 mm intervals in the width direction of the retardation film, and the average value thereof is defined as the film thickness ( ⁇ m) of the retardation film. Further, the difference between the maximum value and the minimum value of the film thickness is defined as film thickness variation ( ⁇ m).
- the retardation of the retardation film is obtained by (1) providing a retardation with a base resin such as cellulose ester (vinegar cotton); (2) providing a retardation by adding a retardation increasing agent;
- a base resin such as cellulose ester (vinegar cotton)
- Ro and Rt vary depending on humidity.
- the latter case is preferable because Ro and Rt hardly change depending on humidity.
- the retardation development property is improved, so that a thin film can be formed.
- the amount of the raising agent added is too large, the haze may be deteriorated.
- plasticity is imparted to the retardation film, and stress is easily applied to the entire retardation film at the time of stretching, and the film thickness variation becomes small (good). Furthermore, since the inside of the retardation film is hydrophobized and does not attract water, fluctuations in Ro and Rt humidity are reduced. However, when there is too much plasticizer, haze may deteriorate, which is not preferable.
- the film thickness of the retardation film As the film thickness of the retardation film is thinner, the total amount of water decreases, so that the Rt humidity fluctuation decreases. However, when the film thickness of the retardation film is too thin, it is difficult to form a uniform film, and the film thickness variation increases (deteriorates).
- the retardation film according to the present invention includes a retardation increasing agent containing the nitrogen-containing compound (A) and the nitrogen-containing compound (B), preferably a base resin such as cellulose as a main component, and if necessary, Other additives such as (a) plasticizer, (b) hydrogen bonding compound, (c) hydrogen bonding compound, and (d) other optional components are further included.
- the “main component” means a component occupying 50% by mass or more of the entire retardation film, preferably 60% by mass or more, and more preferably 70% by mass or more. .
- a retardation increasing agent (also referred to as a retardation developing agent) refers to a compound having a function of increasing the retardation value of a retardation film. Specifically, the retardation value Rt (590) in the thickness direction at a measurement wavelength of 590 nm of the retardation film containing 3 parts by mass of the compound with respect to 100 parts by mass of the base resin is higher than that of the non-added retardation film.
- Ro and Rt humidity fluctuations can be controlled within a desired range by adjusting the type and addition amount of the phase difference increasing agent, the type and addition amount of the plasticizer, and the like.
- the retardation increasing agent contained in the retardation film according to the present invention The following general formula (1):
- Ar is each independently a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted nitrogen-containing aromatic heterocyclic ring, and X 2 and Y 2 are each independently Represents a substituted or unsubstituted nitrogen-containing aromatic heterocycle)
- Ar is each independently a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted nitrogen-containing aromatic heterocyclic ring, and X 3 , Y 3 , and Z 3 are Each independently represents a substituted or unsubstituted nitrogen-containing aromatic heterocycle)
- the nitrogen-containing compound (B) represented by these is included.
- Such a compound can improve the compatibility and orientation of the base resin. Furthermore, the orientation of water molecules to the base resin can be suppressed. These effects are due to the formation of hydrogen bonds with the base resin by the nitrogen atoms in the nitrogen-containing compound, the interaction between the aromatic ⁇ electrons in the nitrogen-containing compound and the base resin, and the like.
- a polarizing plate having a retardation film containing such a retardation increasing agent is used in a liquid crystal display device, a high retardation development property can be obtained, and a retardation variation due to a humidity variation can be reduced. It is possible to suppress a decrease in contrast and color unevenness due to fluctuations.
- each Ar is independently a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted aromatic heterocyclic ring, preferably a substituted or unsubstituted aromatic ring. It is a 5-membered or 6-membered aromatic hydrocarbon ring.
- the structure of the 5-membered or 6-membered aromatic hydrocarbon ring or the 5-membered or 6-membered aromatic heterocyclic ring is not limited, but an aromatic hydrocarbon ring such as a benzene ring; a pyridine ring, a pyrimidine ring, a pyrazine ring, Nitrogen-containing aromatic heterocycles such as pyridazine ring, pyrrole ring, pyrazole ring, imidazole ring, 1,2,3-triazole ring, 1,2,4-triazole ring, tetrazole ring; oxygen-containing aromatic heterocycle such as furan A sulfur-containing aromatic heterocycle such as thiophene; an aromatic heterocycle containing a plurality of heteroatoms such as an oxazole ring, an oxadiazole ring, an oxatriazole ring, an isoxazole ring, etc.
- an aromatic hydrocarbon ring such as a benzene ring
- the nitrogen-containing compounds represented by the general formulas (1) and (2) may have the same kind of aromatic ring or aromatic heterocyclic ring as plural Ars, and may be heterogeneous aromatic rings or aromatics. You may have a heterocyclic ring.
- at least Ar at the terminal is the same kind of aromatic hydrocarbon ring or aromatic heterocyclic ring, more preferably all Ar are the same kind of aromatic hydrocarbon ring. Or it is an aromatic heterocyclic ring.
- the substituent of the 5-membered or 6-membered aromatic hydrocarbon ring, 5-membered or 6-membered aromatic heterocyclic ring, or nitrogen-containing aromatic heterocyclic ring does not greatly affect the effect of the present invention, Can be introduced. Therefore, the substituent is not particularly limited, but specific examples include halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), alkyl groups (methyl group, ethyl group, n-propyl group, isopropyl group, tert- Butyl group, n-octyl group, 2-ethylhexyl group, etc.), cycloalkyl group (cyclohexyl group, cyclopentyl group, 4-n-dodecylcyclohexyl group, etc.), alkenyl group (vinyl group, allyl group, etc.), cycloalkenyl group ( 2-cyclopenten-1-yl, 2-cycl
- an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 5 carbon atoms is preferable, and unsubstituted is particularly preferable.
- the substituent bonded to the carbon atom or hetero atom adjacent to the carbon atom to which X 2 , X 3 , Y 2 , Y 3 , or Z 3 is bonded is unsubstituted. It is preferable that a hetero atom such as a nitrogen atom is unsubstituted.
- the nitrogen-containing heterocyclic structures X 2 and Y 2 in the general formula (1) and the nitrogen-containing heterocyclic structures X 3 , Y 3 and Z 3 in the general formula (2) are each independently substituted or It represents an unsubstituted nitrogen-containing aromatic heterocycle, preferably a substituted or unsubstituted 5- or 6-membered nitrogen-containing aromatic heterocycle.
- Specific examples of X 2 , Y 2 , X 3 , Y 3 , and Z 3 are not particularly limited, but are independently pyrrole ring, imidazole ring, pyrazole ring, pyridine ring, pyrazine ring, pyridazine ring, triazole ring.
- an imidazole ring, a pyrazole ring, or a triazole ring is preferable because a resin composition that is particularly excellent in the effect of suppressing variation in retardation with respect to humidity variation and that is excellent in durability is obtained, and is a pyrazole ring. It is particularly preferred.
- the nitrogen-containing heteroaromatic ring represented by X 2 , X 3 , Y 2 , Y 3 , and Z 3 may be a tautomer.
- nitrogen-containing aromatic heterocyclic structure X 2 or Y 2 in the nitrogen-containing compound represented by the general formula (1), or the general formula (2) is represented by the nitrogen-containing aromatic heterocyclic ring in which the nitrogen-containing aromatic heterocyclic structure X 3 , Y 3 , Z 3 in the nitrogen-containing compound is independently selected from the group consisting of an imidazole ring, a pyrazole ring, or a triazole ring It is a retardation film.
- R 5 represents a substituent similar to the substituent that Ar may have from the viewpoint of ensuring the interaction with a base resin such as cellulose acylate, and is preferably a hydrogen atom.
- X 2 , Y 2 , X 3 , Y 3 , and Z 3 bonded through Ar are bonded through three or more atoms.
- the carbon atom is bonded to the carbon atom or nitrogen atom adjacent to the carbon atom to which Ar is bonded.
- the substituent is preferably hydrogen, and the nitrogen atom is more preferably unsubstituted.
- the bond between Ar and X 2 , Y 2 , X 3 , Y 3 , or Z 3 is a single bond. If it is a single bond, it interacts with the resin chain at the nitrogen-containing heterocyclic moiety, and easily follows the resin chain by suitably twisting at the single bond portion.
- X 2 , Y 2 , X 3 , Y 3 , and Z 3 may have the same type of aromatic heterocycle, and may have different types of aromatic heterocycles. From the viewpoint of optical properties, X 2 , Y 2 , X 3 , Y 3 , and Z 3 are preferably the same kind of aromatic heterocycle.
- the nitrogen-containing compound (A) or the nitrogen-containing compound (B) may form a hydrate, a solvate or a salt.
- the hydrate may contain an organic solvent
- the solvate may contain water. That is, “hydrate” and “solvate” include mixed solvates containing both water and organic solvents.
- Salts include acid addition salts formed with inorganic or organic acids. Examples of inorganic acids include, but are not limited to, hydrohalic acids (hydrochloric acid, hydrobromic acid, etc.), sulfuric acid, phosphoric acid, and the like.
- organic acids examples include acetic acid, trifluoroacetic acid, propionic acid, butyric acid, oxalic acid, citric acid, benzoic acid, alkylsulfonic acid (methanesulfonic acid, etc.), allylsulfonic acid (benzenesulfonic acid, 4-toluene) Sulfonic acid, 1,5-naphthalenedisulfonic acid, and the like), but are not limited thereto.
- hydrochloride, acetate, propionate and butyrate are preferable.
- salts are those in which the acidic moiety present in the parent compound is a metal ion (eg, an alkali metal salt, such as sodium or potassium salt, an alkaline earth metal salt, such as calcium or magnesium salt, an ammonium salt, an alkali metal ion, alkaline earth And salts formed when substituted with organic bases (such as ethanolamine, diethanolamine, triethanolamine, morpholine, piperidine, etc.). Not. Of these, sodium salts and potassium salts are preferred.
- a metal ion eg, an alkali metal salt, such as sodium or potassium salt, an alkaline earth metal salt, such as calcium or magnesium salt, an ammonium salt, an alkali metal ion, alkaline earth
- organic bases such as ethanolamine, diethanolamine, triethanolamine, morpholine, piperidine, etc.
- sodium salts and potassium salts are preferred.
- Examples of the solvent contained in the solvate include any common organic solvent. Specifically, alcohol (eg, methanol, ethanol, 2-propanol, 1-butanol, 1-methoxy-2-propanol, t-butanol), ester (eg, ethyl acetate), hydrocarbon (eg, toluene, hexane) , Heptane), ether (eg, tetrahydrofuran), nitrile (eg, acetonitrile), ketone (acetone) and the like.
- alcohol eg, methanol, ethanol, 2-propanol, 1-butanol, 1-methoxy-2-propanol, t-butanol
- ester eg, ethyl acetate
- hydrocarbon eg, toluene, hexane
- Heptane Heptane
- ether eg, tetrahydrofuran
- nitrile
- solvates of alcohols eg, methanol, ethanol, 2-propanol, 1-butanol, 1-methoxy-2-propanol, t-butanol.
- solvents may be a reaction solvent used at the time of synthesizing the compound, a solvent used at the time of crystallization purification after synthesis, or a mixture thereof.
- two or more kinds of solvents may be included at the same time, or a form containing water and a solvent (for example, water and alcohol (for example, methanol, ethanol, t-butanol, etc.)) may be used.
- a solvent for example, water and alcohol (for example, methanol, ethanol, t-butanol, etc.)
- the nitrogen-containing compound (A) or the nitrogen-containing compound (B) may be added in a form that does not contain water, a solvent, or a salt.
- a hydrate May form solvates or salts.
- the molecular weights of the nitrogen-containing compound (A) and the nitrogen-containing compound (B) are not particularly limited, but the smaller the better the compatibility with the resin, the larger the higher the optical value variation suppression effect with respect to environmental humidity changes, 100 to 2000 is preferable, 200 to 1500 is more preferable, and 300 to 1000 is more preferable.
- nitrogen-containing compound (A) having a structure represented by the general formula (1) used in the present invention include the following.
- nitrogen-containing compound (B) having a structure represented by the general formula (2) used in the present invention include the following.
- the retardation film according to the present invention includes the nitrogen-containing compound (A) and the nitrogen-containing compound (B) represented by the general formulas (1) and (2), and in order to obtain a desired retardation, the nitrogen-containing compound (A) and the nitrogen-containing compound (B) are added to the base resin of the retardation film. Being added in the base resin means being dissolved or dispersed in the base resin. If the nitrogen-containing compound (A) and the nitrogen-containing compound (B) are only applied to the surface of the retardation film, the desired retardation may not be obtained.
- a method of preparing a base resin and a dope in which the nitrogen-containing compound (A) and the nitrogen-containing compound (B) are mixed and casting the solution A method of casting a melt obtained by previously heating and melting a mixture of the material resin and the nitrogen-containing compound (A) and the nitrogen-containing compound (B) may be used.
- the retardation film of the present invention is represented by the following formulas (i) and (ii), the retardation value Ro in the in-plane direction of the retardation film is in the range of 45 to 60 nm, and the retardation in the film thickness direction.
- the value Rt is preferably in the range of 110 to 140 nm from the viewpoint of improving the visibility such as viewing angle and contrast when provided in a VA liquid crystal display device.
- the retardation film can be adjusted within the range of the retardation value by stretching while adjusting the stretching ratio at least in the TD direction.
- n x represents a refractive index in the direction x in which the refractive index is maximized in the plane direction of the film.
- n y in-plane direction of the film, the refractive index in the direction y perpendicular to the direction x.
- nz represents the refractive index in the thickness direction z of the film.
- d represents the thickness (nm) of the film.
- the total amount of nitrogen-containing compound (A) and nitrogen-containing compound (B) used in the retardation film according to the present invention is not particularly limited.
- the compounds represented by the general formulas (1) and (2) are used in a total amount of 0.1 with respect to 100 parts by mass of a resin such as cellulose ester used as a base material for a retardation film.
- the content is preferably in the range of ⁇ 20 parts by mass, more preferably in the range of 1 to 15 parts by mass, still more preferably in the range of 1.5 to 10 parts by mass. More preferably, it is in the range of 3 to 6 parts by mass. Within this range, sufficient retardation is imparted to the retardation film of the present invention, and compatibility and bleedout resistance are improved.
- the content ratio of the nitrogen-containing compound (A) and the nitrogen-containing compound (B) in the retardation increasing agent is nitrogen-containing when the total mass of the nitrogen-containing compound (A) and the nitrogen-containing compound (B) is 100.
- the nitrogen-containing compound (A) and the nitrogen-containing compound (B) can be synthesized by a known method.
- any compound having a 1,2,4-triazole ring may be used, but a method of reacting a nitrile derivative or imino ether derivative with a hydrazide derivative is preferred.
- the solvent used for the reaction may be any solvent as long as it does not react with the raw material, but may be any ester type (eg, ethyl acetate, methyl acetate), amide type (dimethylformamide, dimethylacetamide, etc.), ether type (Ethylene glycol dimethyl ether, etc.), alcohols (eg, methanol, ethanol, propanol, isopropanol, n-butanol, 2-butanol, ethylene glycol, ethylene glycol monomethyl ether, etc.), aromatic hydrocarbons (eg, toluene, xylene, etc.) ), Water can be mentioned.
- an alcohol solvent is preferable. These solvents may be used as a mixture.
- the amount of the solvent used is not particularly limited, but is preferably in the range of 0.5 to 30 times the amount of the hydrazide derivative used, more preferably 1.0 to 25 times the amount. Yes, particularly preferably in the range of 3.0 to 20 times the amount.
- a catalyst When reacting a nitrile derivative and a hydrazide derivative, it is not necessary to use a catalyst, but it is preferable to use a catalyst in order to accelerate the reaction.
- a catalyst to be used an acid may be used and a base may be used.
- the acid include hydrochloric acid, sulfuric acid, nitric acid, acetic acid and the like, preferably hydrochloric acid.
- the acid may be added after diluted in water, or may be added by a method of blowing a gas into the system.
- Bases include inorganic bases (potassium carbonate, sodium carbonate, potassium bicarbonate, sodium bicarbonate, potassium hydroxide, sodium hydroxide, etc.) and organic bases (sodium methylate, sodium ethylate, potassium methylate, potassium ethylate, Sodium butyrate, potassium butyrate, diisopropylethylamine, N, N′-dimethylaminopyridine, 1,4-diazabicyclo [2.2.2] octane, N-methylmorpholine, imidazole, N-methylimidazole, pyridine, etc.) Any of them may be used, and the inorganic base is preferably potassium carbonate, and the organic base is preferably sodium ethylate, sodium ethylate or sodium butyrate.
- the inorganic base may be added as a powder or may be added in a state dispersed in a solvent.
- the organic base may be added in a state dissolved in a solvent (for example, a
- the amount of the catalyst used is not particularly limited as long as the reaction proceeds, but it is preferably in the range of 1.0 to 5.0 moles relative to the formed triazole ring, and more preferably 1.05 to 3. A range of 0-fold mole is preferable.
- the target product can be obtained by heating in a solvent.
- the addition method of the raw material, solvent and catalyst used in the reaction is not particularly limited, and the catalyst may be added last, or the solvent may be added last. Also preferred is a method of dispersing or dissolving a nitrile derivative in a solvent, adding a catalyst, and then adding a hydrazide derivative.
- the solution temperature during the reaction may be any temperature as long as the reaction proceeds, but is preferably in the range of 0 to 150 ° C., more preferably in the range of 20 to 140 ° C. Moreover, you may react, removing the water to produce
- any method may be used for treating the reaction solution, but when a base is used as a catalyst, a method of neutralizing the reaction solution by adding an acid is preferable.
- the acid used for neutralization include hydrochloric acid, sulfuric acid, nitric acid, and acetic acid, and acetic acid is particularly preferable.
- the amount of the acid used for neutralization is not particularly limited as long as the pH of the reaction solution is in the range of 4 to 9, but is preferably 0.1 to 3 moles, particularly preferably, relative to the base used. , In the range of 0.2 to 1.5 moles.
- the appropriate organic solvent is a water-insoluble solvent such as ethyl acetate, toluene, dichloromethane, ether, or a mixed solvent of the water-insoluble solvent and tetrahydrofuran or an alcohol solvent, preferably Ethyl acetate.
- the nitrogen-containing compound (A) or the nitrogen-containing compound (B) is crystallized
- a method of adding water to the neutralized reaction solution to crystallize, or the nitrogen-containing compound (A) or A method of neutralizing and crystallizing the aqueous solution in which the nitrogen-containing compound (B) is dissolved is preferable.
- the 1 H-NMR spectrum of the obtained Exemplified Compound 55 is as follows. In order to avoid complication of chemical shift due to the presence of tautomers, the measurement was performed by adding a few drops of trifluoroacetic acid to the measurement solvent.
- the nitrogen-containing compound (B) represented by the general formula (2) can also be prepared by changing the addition ratio of the reactants in the same reaction.
- Other compounds can be synthesized by the same method.
- the nitrogen-containing compound from which the number of an aromatic-hydrocarbon ring and an aromatic heterocyclic ring differs from a nitrogen-containing compound (A) or a nitrogen-containing compound (B) can be produced
- a compound may be slightly contained in the target product even after separation and purification, but it is usually not contained, and even if it is contained in a trace amount, the wet heat durability that is the object of the present invention is not impaired. If it is within the range, it may be included.
- the retardation film according to the present invention preferably contains a thermoplastic resin as a base resin.
- a base material layer is comprised from the thermoplastic resin which can be extended
- stretchable thermoplastic resins include acrylic resins, styrene resins, cycloolefin resins, cellulose resins, polypropylene resins, polyester resins, or combinations thereof.
- the acrylic resin an acrylic resin containing a structural unit derived from methyl methacrylate as a main component and further comprising a structural unit derived from a monomer component copolymerizable therewith is preferably used.
- the copolymerizable monomer component also includes an acrylic acid derivative having a ring structure.
- the styrenic resin include a styrenic resin containing a structural unit derived from styrene as a main component and further containing a structural unit derived from a monomer component copolymerizable therewith.
- examples of the cycloolefin resin include a norbornene resin called a cycloolefin copolymer.
- examples of the polypropylene-based resin include polypropylene partially containing polyethylene
- examples of the polyester-based resin include polyethylene terephthalate (PET).
- the retardation film contains a cellulose resin.
- cellulose resin Cellulose resin polymerized in presence of cellulose ester, cellulose ether, cationized cellulose, various vinyl monomers, various vinyl monomers, etc.
- a graft polymer or the like is used.
- cellulose ester is particularly preferably used.
- another preferred embodiment of the present invention is a retardation film containing a cellulose-based resin as a main component.
- Cellulose ester is an acyl group in which some or all of the hydrogen atoms of hydroxyl groups (—OH) at the 2nd, 3rd and 6th positions in the ⁇ -1,4 bonded glucose unit constituting cellulose are substituted.
- Cellulose acylate resin is an acyl group in which some or all of the hydrogen atoms of hydroxyl groups (—OH) at the 2nd, 3rd and 6th positions in the ⁇ -1,4 bonded glucose unit constituting cellulose are substituted.
- Cellulose acylate resin is an acyl group in which some or all of the hydrogen atoms of hydroxyl groups (—OH) at the 2nd, 3rd and 6th positions in the ⁇ -1,4 bonded glucose unit constituting cellulose.
- the cellulose ester contained in the retardation film according to the present invention is not particularly limited, but is preferably an ester of a linear or branched carboxylic acid having about 2 to 22 carbon atoms.
- the carboxylic acid constituting the ester may be an aliphatic carboxylic acid, may form a ring, or may be an aromatic carboxylic acid.
- the hydrogen atom of the hydroxyl group of cellulose is an acyl group having 2 to 22 carbon atoms such as acetyl, propionyl, butyryl, isobutyryl, valeryl, pivaloyl, hexanoyl, octanoyl, lauroyl, stearoyl, etc. Examples include substituted cellulose esters.
- the carboxylic acid (acyl group) constituting the ester may have a substituent.
- the carboxylic acid constituting the ester is particularly preferably a lower fatty acid having 6 or less carbon atoms, and more preferably a lower fatty acid having 3 or less carbon atoms.
- the acyl group in the cellulose ester may be a single species or a combination of a plurality of acyl groups.
- cellulose esters include cellulose acetates such as diacetyl cellulose (DAC) and triacetyl cellulose (TAC), cellulose acetate propionate (CAP), cellulose acetate butyrate, and cellulose acetate propionate butyrate.
- DAC diacetyl cellulose
- TAC triacetyl cellulose
- CAP cellulose acetate propionate
- CAP cellulose acetate butyrate
- cellulose acetate propionate butyrate examples thereof include mixed fatty acid esters of cellulose to which a propionate group or a butyrate group is bound in addition to such an acetyl group.
- These cellulose esters may be used singly or in combination of two or more.
- the Ro and Rt humidity fluctuations can be controlled within a desired range by adjusting the type of acyl group and substitution degree of the cellulose ester, and the film thickness uniformity can be improved.
- substitution degree of the acyl group of the cellulose ester is smaller, the retardation development is improved, so that a thin film can be obtained. On the other hand, if the substitution degree of the acyl group is too small, the durability may be deteriorated.
- the greater the substitution degree of the acyl group of the cellulose ester the more the retardation does not appear.Therefore, it is necessary to increase the stretch ratio during film formation, but it is difficult to stretch uniformly at a high stretch ratio. The film thickness variation increases (deteriorates). Further, since the Rt humidity fluctuation is caused by the coordination of water molecules to the carbonyl group of cellulose, the substitution degree of the acyl group is higher, that is, the more carbonyl groups in the cellulose, the worse the Rt humidity fluctuation tends to be. .
- the cellulose ester preferably has a total degree of substitution of 2.1 to 2.5. By setting this range, it is possible to suppress environmental fluctuations (particularly, Rt fluctuations due to humidity) and improve film thickness uniformity. More preferably, it is 2.2 to 2.45 from the viewpoint of improving the castability and stretchability during film formation and further improving the uniformity of the film thickness.
- the cellulose ester satisfies both the following formulas (a) and (b).
- X is the degree of substitution of the acetyl group
- Y is the degree of substitution of the propionyl group or butyryl group, or the degree of substitution of a mixture thereof.
- This is cellulose acetate.
- the cellulose acetate particularly preferably used is 2.1 ⁇ X ⁇ 2.5 (more preferably 2.15 ⁇ X ⁇ 2.45) from the viewpoint that the retardation development, Rt humidity fluctuation, and film thickness variation are in the desired ranges.
- DAC Cellulose diacetate
- CAP cellulose acetate propionate
- CAP that is particularly preferably used is 0.95 ⁇ X ⁇ 2.25, 0.1 ⁇ Y ⁇ 1.2, 2.15 ⁇ X + Y ⁇ . 2.45.
- the degree of substitution of acyl groups indicates the average number of acyl groups per glucose unit, and how many hydrogen atoms of hydroxyl groups at the 2nd, 3rd and 6th positions of 1 glucose unit are substituted with acyl groups. Show. Therefore, the maximum degree of substitution is 3.0. In this case, it means that the hydrogen atoms of the hydroxyl groups at the 2nd, 3rd and 6th positions are all substituted with acyl groups. These acyl groups may be substituted on the 2nd, 3rd and 6th positions of the glucose unit on average, or may be substituted with a distribution. The degree of substitution is determined by the method prescribed in ASTM-D817-96.
- cellulose acetates having different degrees of substitution may be mixed and used.
- the mixing ratio of different cellulose acetates is not particularly limited.
- the number average molecular weight (Mn) of the cellulose ester is in the range of 2 ⁇ 10 4 to 3 ⁇ 10 5 , more preferably in the range of 2 ⁇ 10 4 to 1.2 ⁇ 10 5 , or even 4 ⁇ 10 4 to 8 ⁇ 10.
- the range of 4 is preferred because the mechanical strength of the obtained retardation film is increased.
- the number average molecular weight Mn of the cellulose ester is calculated by measurement using gel permeation chromatography (GPC) under the following measurement conditions.
- the weight average molecular weight (Mw) of the cellulose ester is in the range of 2 ⁇ 10 4 to 1 ⁇ 10 6 , more preferably in the range of 2 ⁇ 10 4 to 1.2 ⁇ 10 5 , or even 4 ⁇ 10 4 to 8 ⁇ 10.
- the range of 4 is preferred because the mechanical strength of the obtained retardation film is increased.
- the weight average molecular weight Mw of the cellulose ester is calculated by measurement using gel permeation chromatography (GPC) under the following measurement conditions.
- the raw material cellulose of the cellulose ester is not particularly limited, and examples thereof include cotton linter, wood pulp, and kenaf. Moreover, the cellulose ester obtained from them can be mixed and used in arbitrary ratios, respectively.
- Cellulose esters such as cellulose acetate and cellulose acetate propionate can be produced by known methods.
- cellulose is esterified by mixing cellulose as a raw material, a predetermined organic acid (such as acetic acid or propionic acid), an acid anhydride (such as acetic anhydride or propionic anhydride), and a catalyst (such as sulfuric acid). The reaction proceeds until the triester is formed. In the triester, the three hydroxy groups (hydroxyl groups) of the glucose unit are substituted with an acyl acid of an organic acid.
- a mixed ester type cellulose ester such as cellulose acetate propionate or cellulose acetate butyrate can be produced.
- a cellulose ester resin having a desired degree of acyl substitution is synthesized by hydrolyzing the cellulose triester. Thereafter, a cellulose ester resin is completed through steps such as filtration, precipitation, washing with water, dehydration, and drying. Specifically, it can be synthesized with reference to the method described in JP-A-10-45804.
- L20, L30, L40, and L50 from Daicel Corporation, Ca398-3, Ca398-6, Ca398-10, Ca398-30, and Ca394-60S from Eastman Chemical Co., Ltd.
- the retardation film according to the present invention may contain the following as other additives.
- the retardation film of the present invention preferably contains at least one plasticizer for the purpose of imparting processability to the retardation film.
- the plasticizers are preferably used alone or in combination of two or more.
- plasticizers containing at least one plasticizer selected from the group consisting of the following sugar ester compounds, polyester compounds, and acrylic compounds effectively controls moisture permeability and base resins such as cellulose esters It is preferable from the viewpoint that the compatibility with is highly compatible.
- the molecular weight of the plasticizer is preferably 15000 or less, and more preferably 10,000 or less from the viewpoint of achieving both improvement in wet heat resistance and compatibility with a base resin such as cellulose ester.
- the weight average molecular weight (Mw) is preferably 10,000 or less.
- a preferable molecular weight (Mw) is in the range of 100 to 10,000, and more preferably in the range of 400 to 8,000.
- the weight average molecular weight (Mw) of the plasticizer is calculated by measurement using gel permeation chromatography (GPC) under the following measurement conditions.
- the compound having a molecular weight of 1500 or less is preferably contained in the range of 6 to 40 parts by mass with respect to 100 parts by mass of the base resin. It is more preferable to make it contain within the range. By containing within the said range, effective control of moisture permeability and compatibility with base-material resin can be made compatible, and it is preferable.
- the retardation film according to the present invention may contain a sugar ester compound for the purpose of preventing hydrolysis.
- a sugar ester compound for the purpose of preventing hydrolysis.
- a sugar ester compound in which at least one pyranose structure or furanose structure is 1 to 12 and all or part of the OH groups in the structure are esterified may be used. it can.
- sugar as a raw material for synthesizing the sugar ester compound according to the present invention examples include the following, but the present invention is not limited to these.
- gentiobiose, gentiotriose, gentiotetraose, xylotriose, galactosyl sucrose, and the like are also included.
- the monocarboxylic acid used for esterifying all or part of the OH group in the pyranose structure or furanose structure is not particularly limited, and is a known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic A monocarboxylic acid or the like can be used.
- the carboxylic acid used may be one type or a mixture of two or more types.
- Examples of 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, Saturation of lauric acid, 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, mellicic acid, and laxaric acid
- unsaturated fatty acids such as fatty acids, undecylenic acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid and o
- Examples of preferable alicyclic monocarboxylic acids include cyclopentane carboxylic acid, cyclohexane carboxylic acid, cyclooctane carboxylic acid, and derivatives thereof.
- aromatic monocarboxylic acids examples include aromatic monocarboxylic acids having 1 to 5 alkyl groups or alkoxy groups introduced into the benzene ring of benzoic acid such as benzoic acid, phenylacetic acid, toluic acid, cinnamic acid, Examples thereof include aromatic monocarboxylic acids having two or more benzene rings such as benzylic acid, biphenylcarboxylic acid, naphthalenecarboxylic acid, tetralincarboxylic acid, or derivatives thereof, and benzoic acid is particularly preferable.
- the retardation film according to the present invention preferably uses a sugar ester compound having a total average degree of substitution represented by the following general formula (FA) of 3.0 to 6.0.
- R 1 to R 8 each independently represents a hydrogen atom, a substituted or unsubstituted alkylcarbonyl group, or a substituted or unsubstituted arylcarbonyl group, and R 1 to R 8 are the same as each other) Or it may be different.
- the compound represented by the general formula (FA) has an average degree of substitution of 3.0 to 6.0, the moisture permeability control and the compatibility with the cellulose ester can be highly compatible.
- the degree of substitution of the compound represented by the general formula (FA) represents the number of substituents other than hydrogen among the eight hydroxyl groups contained in the general formula (FA). Of R 1 to R 8 in formula (FA), this represents the number containing a group other than hydrogen. Accordingly, when all of R 1 to R 8 are substituted with a substituent other than hydrogen, the degree of substitution is 8.0, which is the maximum value, and when R 1 to R 8 are all hydrogen atoms, 0.0 It becomes.
- the compound having the structure represented by the general formula (FA) is difficult to synthesize a single kind of compound in which the number of hydroxyl groups and the number of OR groups are fixed. Since it is known that a compound in which several different components are mixed is used, it is appropriate to use the average substitution degree as the substitution degree of the general formula (FA) in the present specification.
- the average degree of substitution can be measured from the area ratio of the chart showing the degree of substitution distribution by graphy.
- R 1 to R 8 represent a substituted or unsubstituted alkylcarbonyl group or a substituted or unsubstituted arylcarbonyl group, and R 1 to R 8 may be the same or different.
- R 1 to R 8 are also referred to as acyl groups).
- Specific examples of R 1 to R 8 include acyl groups derived from monocarboxylic acids used during the synthesis of the sugar ester compounds exemplified above. Specific examples include a methanoyl group, a benzoyl group, a methylbenzoyl group, a phenylacetyl group, a trimethoxybenzoyl group, and an isopropanyl group.
- the retardation film according to one embodiment of the present invention preferably contains 0.5 to 30% by mass, particularly 2 to 15% by mass of the sugar ester compound based on the entire retardation film (100% by mass). preferable.
- the sugar ester compound can be produced by reacting the sugar with an acylating agent (also referred to as an esterifying agent, for example, an acid halide such as acetyl chloride or an anhydride such as acetic anhydride).
- an acylating agent also referred to as an esterifying agent, for example, an acid halide such as acetyl chloride or an anhydride such as acetic anhydride.
- the distribution of the degree is made by adjusting the amount of the acylating agent, the timing of addition, and the esterification reaction time, but it is possible to mix sugar ester compounds with different degrees of substitution, or to mix purely isolated compounds with different degrees of substitution. Thus, it is possible to adjust a component having a target average substitution degree and a substitution degree of 4 or less.
- the inside of the Kolben was depressurized to 4 ⁇ 10 2 Pa or less, and after excess pyridine was distilled off at 60 ° C., the inside of the Kolben was depressurized to 1.3 ⁇ 10 Pa or less and the temperature was raised to 120 ° C. Most of the acid and benzoic acid formed were distilled off. Then, 1 L of toluene and 300 g of a 0.5% by mass aqueous sodium carbonate solution were added, and the mixture was stirred at 50 ° C. for 30 minutes and then allowed to stand to separate a toluene layer.
- the obtained mixture was analyzed by high performance liquid chromatography / mass spectrometry (HPLC-MS), and the average degree of substitution was 5.5.
- a sugar ester compound having a purity of 100% is obtained by purifying a part of the obtained mixture by column chromatography using silica gel.
- the “A-5 etc.” means a mixture of all components having a substitution degree of 4 or less, that is, compounds having substitution degrees of 4, 3, 2, 1.
- the average degree of substitution was calculated with A-5 as the degree of substitution of 4.
- the average degree of substitution was adjusted by adding in combination the sugar ester close to the desired degree of average substitution and the isolated A-1 to A-5 etc. by the method prepared here.
- the retardation film according to the present invention preferably contains a polyester compound.
- the polyester compound is not particularly limited.
- a polymer (polyester polyol) in which a terminal is a hydroxy group (hydroxyl group), which can be obtained by a condensation reaction of dicarboxylic acid or an ester-forming derivative thereof and glycol, or the polyester A polymer in which the hydroxyl group at the end of the polyol is sealed with a monocarboxylic acid (end-capped polyester) can be used.
- the ester-forming derivative referred to here is an esterified product of dicarboxylic acid, dicarboxylic acid chloride, or dicarboxylic acid anhydride.
- a polyester compound represented by the following general formula (FB) from the viewpoint of highly compatible moisture permeability control and compatibility with cellulose ester.
- Formula (FB) B- (GA) n -GB (In the formula, B represents a hydroxy group or a carboxylic acid residue, G represents an alkylene glycol residue having 2 to 18 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol 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
- n represents an integer of 1 or more.
- FB general formula (FB)
- a hydroxy group or a carboxylic acid residue represented by B an alkylene glycol residue, an oxyalkylene glycol residue or an aryl glycol residue represented by G
- an alkylene dicarboxylic acid residue represented by A or It is composed of an aryl dicarboxylic acid residue and can be obtained by the same reaction as that of a normal ester compound.
- Examples of the carboxylic acid component of the polyester compound represented by the general formula (FB) include acetic acid, propionic acid, butyric acid, benzoic acid, p-tert-butylbenzoic acid, orthotoluic acid, metatoluic acid, p-toluic acid, and dimethylbenzoic acid. , Ethyl benzoic acid, normal propyl benzoic acid, aminobenzoic acid, acetoxybenzoic acid, aliphatic 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 18 carbon atoms of the polyester compound represented by the general formula (FB) examples include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, , 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-1,3-propanediol (3,3-dimethylol) Heptane), 3-methyl-1,5-pentanediol 1,6-hexanediol, 2,2,4-trimethyl-1,3-pe Tandio
- an alkylene glycol having 2 to 12 carbon atoms is particularly preferable because of excellent compatibility with the cellulose ester resin. More preferred are alkylene glycols having 2 to 6 carbon atoms, and still more preferred are alkylene glycols having 2 to 4 carbon atoms.
- Examples of the aryl glycol having 6 to 12 carbon atoms of the polyester compound represented by the general formula (FB) include 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, cyclohexanediethanol, and 1,4-benzenedimethanol. And these glycols can be used as one kind or a mixture of two or more kinds.
- Examples of the oxyalkylene glycol component having 4 to 12 carbon atoms of the polyester compound represented by the general formula (FB) include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol. Yes, these glycols can be used as one or a mixture of two or more.
- Examples of the alkylene dicarboxylic acid component having 4 to 12 carbon atoms of the polyester compound represented by the general formula (FB) include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and dodecane. There exist dicarboxylic acid etc., and these are each used as a 1 type, or 2 or more types of mixture.
- the aryl dicarboxylic acid component having 6 to 12 carbon atoms of the polyester compound represented by the general formula (FB) includes phthalic acid, terephthalic acid, isophthalic acid, 1,5-naphthalenedicarboxylic acid, and 1,4-naphthalenedicarboxylic acid. Etc.
- the polyester compound represented by the general formula (FB) has a weight average molecular weight of preferably 300 to 1500, more preferably 400 to 1000.
- the acid value is 0.5 mgKOH / g or less
- the hydroxy group (hydroxyl group) value is 25 mgKOH / g or less
- more preferably the acid value is 0.3 mgKOH / g or less
- the hydroxy group (hydroxyl group) value is 15 mgKOH / g or less. Is.
- the retardation film according to the present invention preferably contains the polyester compound in an amount of 0.1 to 30% by weight, particularly 0.5 to 10% by weight, based on the entire retardation film (100% by weight). Is preferred.
- the retardation film according to the present invention preferably contains an acrylic compound for the purpose of water resistance.
- the acrylic compound is not particularly limited, but at least one selected from the group consisting of (meth) acrylic acid, (meth) acrylic acid ester, (meth) acrylamides, and (meth) acrylonitrile. Examples thereof include a polymer having a repeating unit derived from a certain acrylic monomer.
- the acrylic compound is preferably one in which the methyl methacrylate unit is 50 to 99% by mass and the total amount of other monomer units copolymerizable therewith is 1 to 50% by mass.
- Examples of other copolymerizable monomers include alkyl methacrylates having an alkyl group having 2 to 18 carbon atoms; alkyl acrylates having an alkyl group having 1 to 18 carbon atoms; amides such as acryloylmorpholine and N, N-dimethylacrylamide
- the acrylic compound used in one embodiment of the present invention may have a ring structure, specifically, a lactone ring structure, a glutaric anhydride structure, a glutarimide structure, an N-substituted maleimide structure, and Examples include maleic anhydride structure and pyran ring structure.
- alkyl acrylates having 1 to 18 carbon atoms in the alkyl group examples include alkyl acrylates having 1 to 18 carbon atoms in the alkyl group, amides such as acryloylmorpholine and dimethylacrylamide, from the viewpoint of thermal decomposition resistance and fluidity of the copolymer.
- amides such as acryloylmorpholine and dimethylacrylamide
- Preferred are a vinyl monomer having a group, a methacrylic acid ester or an acrylate ester having an alicyclic hydrocarbon group having 5 to 22 carbon atoms in the ester portion, an N-substituted maleimide structure, a pyran ring structure and the like.
- alkyl acrylate having 1 to 18 carbon atoms in the alkyl group include methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, s-butyl acrylate, and 2-ethylhexyl acrylate. And methyl acrylate.
- vinyl monomer having an amide group examples include acrylamide, N-methylacrylamide, N-butylacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, acryloylmorpholine, N-hydroxyethylacrylamide, acryloylpyrrolidine, Acryloylpiperidine, methacrylamide, N-methylmethacrylamide, N-butylmethacrylamide, N, N-dimethylmethacrylamide, N, N-diethylmethacrylamide, methacryloylmorpholine, N-hydroxyethylmethacrylamide, methacryloylpyrrolidine, methacryloylpiperidine, N-vinylformamide, N-vinylacetamide, vinylpyrrolidone and the like can be mentioned.
- methacrylic acid ester or acrylate ester having an alicyclic hydrocarbon group having 5 to 22 carbon atoms in the ester moiety include, for example, cyclopentyl acrylate, cyclohexyl acrylate, methyl cyclohexyl acrylate, trimethylcyclohexyl acrylate, Norbornyl acrylate, norbornyl acrylate, cyano norbornyl acrylate, isobornyl acrylate, bornyl acrylate, menthyl acrylate, fentyl acrylate, adamantyl acrylate, dimethyladamantyl acrylate, tricycloacrylate [5.2 1.02,6] dec-8-yl, tricyclo [5.2.1.02,6] dec-4-methyl acrylate, cyclodecyl acrylate, cyclopentyl methacrylate, cyclohexane methacrylate Sil, methyl cyclohexyl me
- isobornyl methacrylate dicyclopentanyl methacrylate, dimethyladamantyl methacrylate and the like can be mentioned.
- N-substituted maleimide examples include N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, Ni-propylmaleimide, N-butylmaleimide, Ni-butylmaleimide, Nt-butylmaleimide, N-laurylmaleimide, N-cyclohexylmaleimide, N-benzylmaleimide, N-phenylmaleimide, N- (2-chlorophenyl) maleimide, N- (4-chlorophenyl) maleimide, N- (4-bromophenyl) phenylmaleimide, N -(2-methylphenyl) maleimide, N- (2-ethylphenylmaleimide), N- (2-methoxyphenyl) maleimide, N- (2,4,6-trimethylphenyl) maleimide, N- (4-benzylphenyl) Maleimide, N- (2,4,6-tribromoph Yl
- N-methylmaleimide N-cyclohexylmaleimide, N-phenylmaleimide and the like can be mentioned.
- the acrylic compound preferably has a weight average molecular weight (Mw) in the range of 15000 or less, more preferably in the range of 10,000 or less, from the viewpoint of achieving both moisture permeability control and compatibility with the cellulose ester. More preferably, it is in the range of 5000 to 10,000.
- Mw weight average molecular weight
- the method for producing the acrylic compound is not particularly limited, and any known method such as suspension polymerization, emulsion polymerization, bulk polymerization, or solution polymerization may be used.
- a polymerization initiator a normal peroxide type and an azo type can be used, and a redox type can also be used.
- the polymerization temperature may be 30 to 100 ° C. for suspension or emulsion polymerization, and 80 to 160 ° C. for bulk or solution polymerization.
- polymerization can be carried out using alkyl mercaptan or the like as a chain transfer agent.
- the acrylic copolymer can be added in the range of 1 to 30 parts by mass with respect to 100 parts by mass of the base resin.
- a styrene compound may be used for the purpose of improving the water resistance of the retardation film in addition to or in place of the sugar ester compound, the polyester compound and the acrylic compound.
- the styrenic compound may be a homopolymer of a styrenic monomer or a copolymer of a styrenic monomer and another copolymerizable monomer.
- the content of the structural unit derived from the styrenic monomer in the styrenic compound may be preferably 30 to 100 mol%, more preferably 50 to 100 mol%, in order for the molecular structure to have a certain bulkiness.
- the styrene monomer is preferably a compound represented by the following formula (A).
- R 101 to R 103 in the formula (A) each independently represent a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or an aryl group.
- R 104 is a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a cycloalkyl group, an aryl group, an alkoxy group having 1 to 30 carbon atoms, an aryloxy group, an alkyloxycarbonyl group having 2 to 30 carbon atoms, an aryloxycarbonyl Group, an alkylcarbonyloxy group having 2 to 30 carbon atoms, an arylcarbonyloxy group, a hydroxyl group, a carboxyl group, a cyano group, an amino group, an amide group, and a nitro group.
- Each of these groups may further have a substituent (for example, a hydroxyl group, a halogen atom, an alkyl group, etc.).
- R 104 may be the same as or different from each other, and may be bonded to each other to form a ring.
- styrenic monomers include styrene; alkyl-substituted styrenes such as ⁇ -methylstyrene, ⁇ -methylstyrene, and p-methylstyrene; halogen-substituted styrenes such as 4-chlorostyrene and 4-bromostyrene; p-hydroxy Hydroxystyrenes such as styrene, ⁇ -methyl-p-hydroxystyrene, 2-methyl-4-hydroxystyrene, 3,4-dihydroxystyrene; vinylbenzyl alcohols; p-methoxystyrene, p-tert-butoxystyrene, m Alkoxy substituted styrenes such as tert-butoxystyrene; vinyl benzoic acids such as 3-vinylbenzoic acid and 4-vinylbenzoic acid; 4-vinylbenzyl acetate; 4-acetoxy
- the copolymerizable monomer combined with the styrenic monomer is a (meth) acrylic acid ester compound represented by the following formula (B), maleic anhydride, citraconic anhydride, cis-1-cyclohexene-1,2-dicarboxylic anhydride, Acid anhydrides such as 3-methyl-cis-1-cyclohexene-1,2-dicarboxylic anhydride and 4-methyl-cis-1-cyclohexene-1,2-dicarboxylic anhydride, and nitrile groups such as acrylonitrile and methacrylonitrile -Containing radical polymerizable monomers; amide bond-containing radical polymerizable monomers such as acrylamide, methacrylamide, trifluoromethanesulfonylaminoethyl (meth) acrylate; fatty acid vinyls such as vinyl acetate; chlorine such as vinyl chloride and vinylidene chloride Containing radical polymerizable monomer; 1,
- R 105 to R 107 in the formula (B) each independently represent a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or an aryl group.
- R 108 represents a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a cycloalkyl group, or an aryl group.
- Each of these groups may further have a substituent (for example, a hydroxyl group, a halogen atom, an alkyl group, etc.).
- (meth) acrylic acid ester compounds include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate (i-, n-), butyl (meth) acrylate (n- , I-, s-, tert-), pentyl (meth) acrylate (n-, i-, s-), hexyl (meth) acrylate (n-, i-), heptyl (meth) acrylate (n -, I-), octyl (meth) acrylate (n-, i-), nonyl (meth) acrylate (n-, i-), myristyl (meth) acrylate (n-, i-), (meta ) Acrylic acid (2-ethylhexyl), (meth) acrylic acid ( ⁇ -caprolactone), (meth) acrylic acid (2-hydroxyethyl), acrylic acid (2-hydroxypropyl
- styrene compound examples include styrene / maleic anhydride copolymer, styrene / acrylic ester copolymer, styrene / hydroxystyrene polymer, styrene / acetoxystyrene polymer, and the like. Of these, a styrene / maleic anhydride copolymer is preferable.
- the styrene compound can be added in the range of 1 to 30 parts by mass with respect to 100 parts by mass of the base resin.
- Other plasticizers are not particularly limited, but preferably from polycarboxylic acid ester plasticizers, glycolate plasticizers, phthalate ester plasticizers, fatty acid ester plasticizers, and polyhydric alcohol ester plasticizers. Selected.
- a suitable plasticizer is a polyhydric alcohol ester plasticizer.
- examples of preferable polyhydric alcohol ester compounds include compounds described in paragraphs [0170] to [0218] of JP2010-32655A. Among these, it is preferable to use pentaerythritol tetrabenzoate.
- plasticizers are preferably contained in the range of 6 to 40 parts by mass with respect to 100 parts by mass of the base resin, and are preferably contained in the range of 10 to 20 parts by mass.
- the retardation film according to the present invention contains a hydrogen bonding compound in order to reduce the phase difference variation with respect to the change in humidity.
- the hydrogen bonding compound preferably has at least a plurality of functional groups selected from hydroxy groups, amino groups, thiol groups, and carboxylic acid groups in one molecule, and has a plurality of different functional groups in one molecule. It is more preferable to have a hydroxy group and a carboxylic acid group in one molecule.
- the hydrogen bonding compound preferably contains 1 to 2 aromatic rings as a mother nucleus, and the value obtained by dividing the number of functional groups contained in one molecule by the molecular weight of the compound is 0.00. It is preferably 01 or more.
- the hydrogen bonding compound can be added in the range of 1 to 30 parts by mass with respect to 100 parts by mass of the base resin.
- the retardation film according to the present invention contains other optional components such as an antioxidant, a colorant, an ultraviolet absorber, a matting agent, acrylic particles, a hydrogen bonding solvent, and an ionic surfactant. May be included. These components can be added in the range of 0.01 to 20 parts by mass with respect to 100 parts by mass of the base resin.
- antioxidant In the retardation film according to the present invention, those generally known can be used as the antioxidant.
- lactone, sulfur, phenol, double bond, hindered amine, and phosphorus compounds can be preferably used.
- lactone compound examples include “IrgafosXP40, IrgafosXP60 (trade name)” commercially available from BASF Japan.
- sulfur compound examples include “Sumilizer TPL-R” and “Sumilizer TP-D” commercially available from Sumitomo Chemical Co., Ltd.
- the phenolic compound preferably has a 2,6-dialkylphenol structure.
- “Irganox (registered trademark) 1076”, “Irganox (registered trademark) 1010” commercially available from BASF Japan Ltd.
- Examples thereof include “ADEKA STAB (registered trademark) AO-50” commercially available from ADEKA Corporation.
- the above-mentioned double bond compounds are commercially available from Sumitomo Chemical Co., Ltd. under the trade names “Sumilizer (registered trademark) GM” and “Sumilizer (registered trademark) GS”. In general, it is added in an amount of 0.05 to 20% by weight, preferably 0.1 to 1% by weight, based on the resin.
- hindered amine compounds examples include “Tinvin (registered trademark) 144” and “Tinvin (registered trademark) 770” commercially available from BASF Japan, and “ADK STAB (registered trademark)” commercially available from ADEKA. LA-52 ".
- Examples of the phosphorus compounds include “Sumilizer (registered trademark) GP” commercially available from Sumitomo Chemical Co., Ltd., “ADK STAB (registered trademark) PEP-24G” and “ADK STAB (commercially available from ADEKA). (Registered trademark) PEP-36 “and” ADK STAB (registered trademark) 3010 ",” IRGAFOS P-EPQ “commercially available from BASF Japan, and” GSY-P101 "commercially available from Sakai Chemical Industry Co., Ltd. Can be mentioned.
- antioxidants and the like can be appropriately added in accordance with the process of recycling, but in general, with respect to the resin that is the main raw material of the retardation film (for example, cellulose ester), It is added in the range of 0.05 to 20% by mass, preferably 0.1 to 1% by mass.
- antioxidants can obtain a synergistic effect by using several different types of compounds in combination rather than using only one kind.
- the combined use of lactone, phosphorus, phenol and double bond compounds is preferred.
- the retardation film of the present invention preferably contains a colorant for color adjustment within a range not impairing the effects of the present invention.
- the colorant means a dye or a pigment.
- the colorant means an effect having the effect of making the color tone of the liquid crystal screen blue, adjusting the yellow index, or reducing haze.
- dyes and pigments can be used as the colorant, but anthraquinone dyes, azo dyes, phthalocyanine pigments and the like are effective.
- the retardation film of the present invention can be used on the viewing side or the backlight side of the polarizing plate, it may contain an ultraviolet absorber for the purpose of imparting an ultraviolet absorbing function.
- the ultraviolet absorber is not particularly limited, and examples thereof include ultraviolet absorbers such as benzotriazole, 2-hydroxybenzophenone, and salicylic acid phenyl ester.
- ultraviolet absorbers such as benzotriazole, 2-hydroxybenzophenone, and salicylic acid phenyl ester.
- 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis ( ⁇ , ⁇ -dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (3 Triazoles such as 5-di-t-butyl-2-hydroxyphenyl) benzotriazole, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone And benzophenones.
- UV absorbers with a molecular weight of 400 or more are not easily sublimated or volatilized at a high boiling point, and are difficult to disperse even when the retardation film is dried at high temperature. From the viewpoint of effectively improving the weather resistance.
- Examples of the ultraviolet absorber having a molecular weight of 400 or more include 2- [2-hydroxy-3,5-bis ( ⁇ , ⁇ -dimethylbenzyl) phenyl] -2-benzotriazole, 2,2-methylenebis [4- ( Benzotriazoles such as 1,1,3,3-tetrabutyl) -6- (2H-benzotriazol-2-yl) phenol], bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, Hindered amines such as bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butyl Bis (1,2,2,6,6-pentamethyl-4-piperidyl) malonate, 1- [2- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionylo Xyl] ethyl] -4- [3- (3
- 2- [2-hydroxy-3,5-bis ( ⁇ , ⁇ -dimethylbenzyl) phenyl] -2-benzotriazole and 2,2-methylenebis [4- (1,1,3,3- Tetrabutyl) -6- (2H-benzotriazol-2-yl) phenol] is particularly preferred.
- Tinuvin (registered trademark) 109 Tinuvin (registered trademark) 171, Tinuvin (registered trademark) 234, Tinuvin (registered trademark) 326 manufactured by BASF Japan Ltd. may be used.
- Tinuvin series such as Tinuvin (registered trademark) 327, Tinuvin (registered trademark) 328, Tinuvin (registered trademark) 928, or 2,2′-methylenebis [6- (2H-benzotriazol-2-yl) -4- ( 1,1,3,3-tetramethylbutyl) phenol] (molecular weight 659; as an example of a commercially available product, LA31 manufactured by ADEKA Corporation) can be preferably used.
- the above ultraviolet absorbers can be used alone or in combination of two or more.
- the amount of the UV absorber used is not uniform depending on the type of UV absorber, the operating conditions, and the like, but generally 0.05 to 10% by mass, preferably 0.1 to 5% by mass with respect to the base resin. % Is added.
- ⁇ Matting agent> In the retardation film of the present invention, it is preferable to add fine particles (matting agent) that impart the slipperiness of the retardation film.
- the matting agent may be either an inorganic compound or an organic compound as long as it does not impair the transparency of the obtained retardation film and has heat resistance during melting. These matting agents can be used alone or in combination of two or more.
- High transparency and slipperiness can be achieved at the same time by using particles having different particle sizes and shapes (for example, needle shape and spherical shape).
- silicon dioxide which is excellent in transparency (haze) is particularly preferably used since it has a refractive index close to that of the acrylic copolymer or cellulose ester used as a compatible resin.
- silicon dioxide examples include Aerosil (registered trademark) 200V, Aerosil (registered trademark) R972V, Aerosil (registered trademark) R972, R974, R812, 200, 300, R202, OX50, TT600, NAX50 (above Nippon Aerosil Co., Ltd.) Manufactured), Seahoster (registered trademark) KEP-10, Seahoster (registered trademark) KEP-30, Seahoster (registered trademark) KEP-50 (manufactured by Nippon Shokubai Co., Ltd.), Silo Hovic (registered trademark) 100 (Fuji Silysia) Commercially available products having trade names such as NIPSEAL (registered trademark) E220A (manufactured by Nippon Silica Industry Co., Ltd.), Admafine (registered trademark) SO (manufactured by Admatechs Co., Ltd.) and the like can be preferably used.
- NIPSEAL registered trademark
- the shape of the particles can be used without particular limitation, such as indefinite shape, needle shape, flat shape, spherical shape, etc.
- the use of spherical particles is particularly preferable because the obtained retardation film can have good transparency.
- the particle size is preferably smaller than the wavelength of visible light, and more preferably 1 ⁇ 2 or less of the wavelength of visible light. . If the size of the particles is too small, the slipperiness may not be improved, so the range of 80 nm to 180 nm is particularly preferable.
- the particle size means the size of the aggregate when the particle is an aggregate of primary particles. Moreover, when a particle is not spherical, it means the diameter of a circle corresponding to the projected area.
- the matting agent is added in an amount of 0.05 to 10% by mass, preferably 0.1 to 5% by mass with respect to the base resin.
- the retardation film of the present invention may contain acrylic particles described in International Publication No. 2010/001668 in an amount within a range where transparency can be maintained.
- Examples of such commercially available products having a multilayer structure acrylic granular composite include, for example, “Metablene (registered trademark) W-341” manufactured by Mitsubishi Rayon Co., Ltd., “Kaneace (registered trademark)” manufactured by Kaneka Corporation, “Paraloid (registered trademark)” manufactured by Kureha Co., Ltd., “Acryloid” manufactured by Rohm and Haas, “Staffyroid (registered trademark)” manufactured by Ganz Kasei Kogyo, Chemisnow (registered trademark) MR-2G, MS-300X (Above, manufactured by Soken Chemical Co., Ltd.) and “Parapet (registered trademark) SA” manufactured by Kuraray Co., Ltd., and the like. These can be used alone or in combination of two or more.
- a hydrogen bonding solvent is added to the solvent for dissolving the constituent materials of the retardation film for the purpose of adjusting (reducing) the solution viscosity. be able to.
- the hydrogen bonding solvent is J.I. N.
- a hydrogen bond is added to the solvent for dissolution.
- a part or all of the solvent may be used.
- ionic surfactant examples include a cationic surfactant, an anionic surfactant, and an amphoteric surfactant.
- cationic surfactant examples include aliphatic amine salts, aliphatic quaternary ammonium salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts, and the like.
- anionic surfactant examples include higher alcohol (C 8 -C 22 ) sulfate salts (for example, sodium salt of lauryl alcohol sulfate, sodium salt of octyl alcohol sulfate, ammonium salt of lauryl alcohol sulfate, “Tepol-81” ( Trade name, manufactured by Shell Chemical Co., Ltd.), secondary sodium alkyl sulfate, etc.), aliphatic alcohol phosphate salts (eg, sodium salt of cetyl alcohol phosphate), alkylaryl sulfonates (eg, dodecylbenzenesulfonic acid) Sodium salt, isopropyl naphthalene sulfonic acid sodium salt, dinaphthalenedisulfonic acid sodium salt, metanitrobenzene sulfonic acid sodium salt), alkylamide sulfonates (eg Examples thereof include C 17 H 33 CON (CH 3 ) CH 2 SO 3 Na) and sulfonates of dibas
- amphoteric surfactants include carboxybetaine type, sulfobetaine type, aminocarboxylate, imidazolinium betaine and the like.
- an anionic surfactant is preferable in the present invention.
- the surfactant is 0.01% by mass or more and 5% by mass or less, preferably 0.05% by mass or more and 3% by mass or less, more preferably based on the total amount of the base resin constituting the retardation film. It is preferable to use at 0.2 mass% or more and 2 mass% or less. When the addition amount is larger than this range, a quality undesirable for the quality of the optical retardation film is exhibited, such as precipitation of a surfactant from the retardation film and an increase in the hygroscopicity of the retardation film. If the addition amount is less than this range, the effect of the present invention using a surfactant may not be obtained.
- the retardation film of the present invention has (1) a film thickness of 15 ⁇ m or more and 35 ⁇ m or less, and (2) a film thickness variation in the width direction and the longitudinal direction both of 0 to 4 ⁇ m. 3) It is preferable that the Ro fluctuation range represented by the above formula (1) is within ⁇ 4% and the Rt fluctuation range is within ⁇ 5%.
- the above (1) to (3) are: (a) casting conditions of dope and melt, (b) stretching conditions, (c) type and substitution degree of acyl group when cellulose ester is used as the base resin, (D) Satisfies by controlling the types and addition amounts of the nitrogen-containing compound (A) and the nitrogen-containing compound (B) contained in the retardation increasing agent according to the present invention, and (e) the type and addition amount of the plasticizer. be able to.
- the retardation film according to the present invention preferably has a total substitution degree of cellulose ester of 2.1 to 2.5.
- the retardation film according to another embodiment of the present invention has a cellulose ester total substitution degree of 2.1 to 2.5 (more preferably 2.15 to 2.45), and a sugar ester compound, It contains at least one plasticizer selected from the group consisting of polyester compounds and acrylic compounds. More preferably, the plasticizer includes a sugar ester compound.
- the total degree of substitution of cellulose ester is 2.1 to 2.5 (more preferably 2.15 to 2.45), and the hydrogen bonding property Contains compounds.
- the film forming method is preferably a solution casting film forming method and a melt casting film forming method. Is more preferable for obtaining.
- the method for producing a retardation film of the present invention comprises a step of preparing a dope by dissolving a thermoplastic resin and the above-mentioned additive in a solvent (dissolution step; dope preparation step), Casting onto an endless metal support that moves indefinitely (casting process), drying the cast dope as a web (solvent evaporation process), peeling from the metal support (peeling process), drying It is preferable to include a step of stretching and maintaining the width (stretching / width maintaining / drying step) and a step of winding the finished retardation film (winding step).
- the thermoplastic resin it is particularly preferable to use a cellulose ester.
- FIG. 1 is a diagram schematically showing an example of a dope preparation step, a casting step, and a drying step (solvent evaporation step) of a solution casting film forming method preferable for the present invention.
- the main dope is filtered by the main filter 3, and the additive solution is added in-line from 16 to this.
- the main dope may contain about 10 to 50% by weight of recycled material.
- Recycled material is a product obtained by finely pulverizing a retardation film, which is generated when a retardation film is formed, a product obtained by cutting off both sides of a retardation film, or a retardation film original that has been speculated out due to scratches, etc. Anti is used.
- a material obtained by pelletizing cellulose ester and other additives as a base resin in advance can be preferably used as a raw material of the resin used for preparing the dope.
- dissolution process (dope preparation process)
- a dissolution process will be described by taking a case of using a cellulose ester as a thermoplastic resin as an example, but the present invention is not limited to this.
- This step is a step of dissolving the cellulose ester in a dissolving kettle mainly with a good solvent for the cellulose ester and optionally other compounds while stirring to form a dope, or the cellulose ester solution.
- the other compound solution is mixed to form a dope which is a main solution.
- the concentration of cellulose ester 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 ester is too high, the load during filtration increases and the filtration accuracy is poor. Become.
- the concentration for achieving both of these is preferably 10 to 35% by mass, and more preferably 15 to 30% by mass.
- Solvents 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 ester in terms of production efficiency, and there are many good solvents. This is preferable from the viewpoint of solubility of cellulose acetate.
- the 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 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 the cellulose ester the solvent removed from the retardation film by drying in the retardation film forming process is recovered and reused.
- the recovery solvent may contain trace amounts of additives added to the cellulose ester, such as plasticizers, UV absorbers, polymers, monomer components, etc., but even if these are included, they are preferably reused. Can be purified and reused if necessary.
- additives added to the cellulose ester such as plasticizers, UV absorbers, polymers, monomer components, etc., but even if these are included, they are preferably reused. Can be purified and reused if necessary.
- a general method can be used as a method for dissolving the cellulose ester when preparing the dope described above. Specifically, a method carried out at normal pressure, a method carried out below the boiling point of the main solvent, a method carried out under pressure above the boiling point of the main solvent, JP-A-9-95544, JP-A-9-95557, Various dissolution methods such as a method using a cooling dissolution method as described in Kaihei 9-95538 and a method using a high pressure as described in Japanese Patent Application Laid-Open No. 11-21379 can be used. Among them, a method of performing pressurization at a temperature equal to or higher than the boiling point of the main solvent is preferable.
- a method of stirring and dissolving while heating at a temperature that is equal to or higher than the boiling point of the solvent at normal pressure and does not boil under pressure is preferable in order to prevent the generation of massive undissolved material called gel or mako.
- 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.
- the 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 still 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 the cellulose ester can be dissolved in a solvent such as methyl acetate.
- the cellulose ester solution (doping during or after dissolution) is preferably filtered using a suitable filter medium such as filter paper.
- the absolute filtration accuracy is small in order to remove insoluble matters and the like.
- the absolute filtration accuracy is too small, there is a problem that the filter medium is likely to be clogged.
- 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. More preferably, it is 100 pieces / cm 2 or less, still more preferably 50 pieces / m 2 or less, still more 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.
- the preferred temperature is 45 to 120 ° C, more preferably 45 to 70 ° C, and still more 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 dope is cast on a metal support. That is, in this step, the dope is fed to the pressurizing die 30 through a liquid feed pump (for example, a pressurized metering gear pump) and transferred indefinitely, such as an endless metal belt 31 such as a stainless steel band or a rotating metal drum. The dope is cast from the pressure die slit to the casting position on the metal support.
- a liquid feed pump for example, a pressurized metering gear pump
- ⁇ Pressure dies that can adjust the slit shape of the die base and make the film thickness uniform are preferred.
- the pressure die include a coat hanger die and a T die, and any of them is preferably used.
- the surface of the metal support is preferably a mirror surface.
- two or more pressure dies may be provided on the metal support, and the dope amount may be divided and stacked.
- the cast width is preferably 1.4 m or more from the viewpoint of productivity. More preferably, it is 1.4 to 4 m. When it exceeds 4 m, there is a risk of streaking in the manufacturing process or lowering of stability in the subsequent transport process. More preferably, it is 2 to 3.5 m in terms of transportability and productivity.
- 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 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 rate can be increased. May deteriorate.
- the preferred support temperature is 0 to 55 ° C, more preferably 22 to 50 ° 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. It is preferable to use warm water because heat transfer is performed efficiently, so that the time until the temperature of the metal support becomes constant is short. When warm air is used, wind at a temperature higher than the target temperature may be used.
- Solvent evaporation step This step is a step of evaporating the solvent by heating the web (the dope is cast on the casting support and the formed dope film is called the web) on the casting support. It is.
- the drying efficiency is good and preferable.
- a method of combining them is also preferably used.
- the web on the support after casting is preferably dried on the support in an atmosphere of 35 to 100 ° C. In order to maintain the atmosphere at 35 to 100 ° C., it is preferable to apply hot air at this temperature to the upper surface of the web or heat by means such as infrared rays.
- peeling step Next, the web is peeled from the metal support. That is, this step is a step of peeling the web where the solvent is evaporated on the metal support at the peeling position. The peeled web is sent to the next process.
- the temperature at the peeling position on the metal support is preferably in the range of ⁇ 50 to 40 ° C., more preferably in the range of 10 to 40 ° C., and most preferably in the range of 15 to 30 ° C.
- the residual solvent amount at the time of peeling of the web on the metal support at the time of peeling is appropriately adjusted depending on the strength of drying conditions, the length of the metal support, and the like.
- the amount of residual solvent when peeling the web from the metal support is preferably 10 to 150% by mass.
- the amount is decided. More preferably, it is 20 to 40% by mass or 60 to 130% by mass, and particularly preferably 20 to 30% by mass or 70 to 120% by mass.
- the amount of residual solvent is defined by the following formula.
- M is the mass of a sample collected at any time during or after production of the web or retardation film
- N is the mass after heating M at 115 ° C. for 1 hour.
- the peeling tension when peeling the metal support and the retardation film is 300 N / m or less. More preferably, it is within the range of 196 to 245 N / m. However, when wrinkles easily occur during peeling, peeling with a tension of 190 N / m or less is preferable. Peeling is preferably performed at a peeling tension of 300 N / m or less.
- the web is peeled off from the metal support, and further dried, and the residual solvent amount is preferably 1% by mass or less, more preferably 0.1% by mass or less, and particularly preferably. Is 0 to 0.01% by mass or less.
- a roll drying method (a method in which webs are alternately passed through a plurality of rolls arranged above and below) and a method of drying while transporting the web by a tenter method are generally employed.
- a drying device 35 that alternately conveys the web through rollers arranged in the drying device and / or a tenter stretching device 34 that clips and conveys both ends of the web with a clip, dry.
- 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 from the viewpoint of simplicity. Too rapid drying tends to impair the flatness of the finished retardation film. Drying at a high temperature is preferably performed from about 8% by mass or less of the residual solvent. Throughout, the drying is generally carried out within the range of 30 to 250 ° C. It is particularly preferable to dry within the range of 35 to 200 ° C. The drying temperature is preferably increased stepwise.
- tenter stretching apparatus When using a tenter stretching apparatus, it is preferable to use an apparatus capable of independently controlling the gripping length of the retardation film (distance from the start of gripping to the end of gripping) left and right by the left and right gripping means of the tenter. In the tenter process, it is also preferable to intentionally create sections having different temperatures in order to improve planarity.
- the web peeled from the metal support is preferably stretched in at least one direction.
- the orientation of molecules in the retardation film can be controlled by stretching.
- the retardation film has the structure of the present invention, and the refractive index is controlled by controlling the transport tension and stretching.
- the retardation value can be changed by lowering or increasing the tension in the longitudinal direction.
- the biaxially stretched retardation film is biaxially stretched in the casting direction (MD direction) and the width direction (TD direction), but the retardation film according to the present invention is a uniaxially stretched retardation film. It may be an unstretched retardation film.
- the stretching operation may be performed in multiple stages. When biaxial stretching is performed, simultaneous biaxial stretching may be performed or may be performed stepwise.
- stepwise means that, for example, stretching in different stretching directions can be sequentially performed, stretching in the same direction is divided into multiple stages, and stretching in different directions is added to any one of the stages.
- stretching steps are possible: -Stretch in the casting direction-> Stretch in the width direction-> Stretch in the casting direction-> Stretch in the casting direction-> Stretch in the casting direction-Stretch in the width direction-> Stretch in the casting direction-> Stretch in the casting direction- Simultaneous biaxial stretching includes stretching in one direction and contracting the other while relaxing the tension.
- 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 preferably performed in the range of 0.8 to 1.2 times in the extending direction and 1.2 to 2.0 times in the width direction.
- the stretching temperature is usually preferably performed in the temperature range of Tg to Tg + 60 ° C. of the resin constituting the retardation film.
- the stretching temperature is preferably 120 ° C. to 200 ° C., more preferably 120 ° C. to 180 ° C.
- the residual solvent in the web during stretching is preferably 20 to 0%, more preferably 15 to 0%.
- the residual solvent is stretched by 8% at 135 ° C, or the residual solvent is stretched by 11% at 155 ° C.
- the residual solvent is preferably stretched at 2% at 155 ° C., or it is preferably stretched at less than 1% at 160 ° C.
- the method of stretching the web For example, a method in which a difference in peripheral speed is applied to a plurality of rolls, and the roll peripheral speed difference is used to stretch in the longitudinal direction, the 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. Among them, it is particularly preferable to perform stretching in the width direction (lateral direction) by a tenter method in which both ends of the web are gripped by clips or the like.
- a tenter it may be a pin tenter or a clip tenter.
- ⁇ 1 is preferably ⁇ 1 ° or more and + 1 ° or less, It is more preferably ⁇ 0.5 ° or more and + 0.5 ° or less.
- This ⁇ 1 can be defined as an orientation angle, and ⁇ 1 can be measured using an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments).
- KOBRA-21ADH manufactured by Oji Scientific Instruments.
- a phase difference film is obtained by winding the obtained web (finished phase difference film). More specifically, after the residual solvent amount in the web is 2% by mass or less, it is a step of winding it as a retardation film by the winder 37, and by setting the residual solvent amount to 0.4% by mass or less. A retardation film having good dimensional stability can be obtained. In particular, it is preferable to wind in the range of 0.00 to 0.10% by mass.
- a generally used one may be used, and there are a constant torque method, a constant tension method, a taper tension method, a program tension control method with a constant internal stress, etc., and these may be used properly.
- knurling embssing
- the knurling method can process a metal ring having an uneven pattern on its side surface by heating or pressing. Note that the clip holding portions at both ends of the retardation film are usually excised because the retardation film is deformed and cannot be used as a product. If the material has not deteriorated due to heat, it is reused after recovery.
- the retardation film of the present invention is preferably a long retardation film.
- the retardation film has a thickness of about 100 m to 10000 m, and is usually provided in a roll form.
- the width of the retardation film is preferably 1.3 to 4 m, more preferably 1.4 to 4 m, in order to meet demands for an increase in the size of liquid crystal display devices and production efficiency. More preferably, it is ⁇ 3 m.
- the retardation film of the present invention can also be formed by a melt casting method.
- the melt film-forming method refers to a method in which a composition containing a thermoplastic resin and the above-mentioned additives is heated and melted to a temperature showing fluidity, and then a melt containing the fluid thermoplastic resin is cast.
- a thermoplastic resin it is particularly preferable to use a cellulose ester.
- the molding method for heating and melting can be classified in detail into a melt extrusion molding method, a press molding method, an inflation method, an injection molding method, a blow molding method, a stretch molding method, and the like.
- the melt extrusion method is preferable from the viewpoint of mechanical strength and surface accuracy.
- the plurality of raw materials used in the melt extrusion method are usually preferably kneaded in advance and pelletized.
- Pelletization may be performed by a known method, for example, dry cellulose ester, plasticizer, and other additives are fed to an extruder with a feeder, kneaded using a monoaxial or biaxial extruder, and formed into a strand from a die. It can be carried out by extruding, water cooling or air cooling and cutting.
- Additives may be mixed before being supplied to the extruder, or may be supplied by individual feeders.
- a small amount of additives such as particles and antioxidants are preferably mixed in advance in order to mix uniformly.
- the extruder is preferably processed at as low a temperature as possible so that the shearing force is suppressed and the resin can be pelletized so as not to deteriorate (molecular weight reduction, coloring, gel formation, etc.).
- a twin screw extruder it is preferable to rotate in the same direction using a deep groove type screw. From the uniformity of kneading, the meshing type is preferable.
- a retardation film is formed.
- the raw material powder can be directly fed to the extruder by a feeder without being pelletized, and a retardation film can be formed as it is.
- the melting temperature when extruding the above pellets using a single-screw or twin-screw type extruder is set to a temperature range of 200 to 300 ° C., filtered through a leaf disk type filter, etc.
- a phase difference film is cast from a die, and the phase difference film is nipped by a cooling roller and an elastic touch roller and solidified on the cooling roller.
- a method for preventing oxidative decomposition or the like under vacuum, reduced pressure, or inert gas atmosphere when introducing from the supply hopper to the extruder is also preferable.
- the extrusion flow rate is preferably carried out stably by introducing a gear pump.
- a stainless fiber sintered filter is preferably used as a filter used for removing foreign substances.
- the stainless steel fiber sintered filter is made by compressing the intricately intertwined state of the stainless steel fiber body and sintering and integrating the contact points. The density changes depending on the thickness of the fiber and the amount of compression, and the filtration accuracy Can be adjusted.
- Additives such as plasticizers and particles may be mixed with the resin in advance, or may be kneaded in the middle of the extruder. In order to add uniformly, it is preferable to use a mixing apparatus such as a static mixer.
- the retardation film temperature on the touch roller side is preferably in the temperature range of Tg to Tg + 110 ° C. of the retardation film.
- a known roller can be used as the roller having an elastic surface used for such a purpose.
- the elastic touch roller is also called a pinching rotary body.
- a commercially available elastic touch roller can also be used.
- the retardation film obtained as described above is stretched by the stretching operation after passing through the step of contacting the cooling roller.
- a known roller stretching machine or tenter can be preferably used. Specific conditions are the same as in the case of the solution pouring method.
- the retardation film obtained as described above is wound to obtain a retardation film.
- FIG. 2 is a schematic cross-sectional view showing an example of the configuration of a polarizing plate provided with the retardation film of the present invention and a liquid crystal display device provided with the polarizing plate.
- the polarizing plate according to one embodiment of the present invention essentially includes at least one retardation film according to one embodiment of the present invention and a polarizer.
- the protective film 102, the active energy ray-curable adhesive 103A, and the polarizer 104 are laminated in this order, and the protective film is disposed. It is a preferable embodiment that the active energy ray-curable adhesive 103B and the retardation film 105 according to the present invention are laminated on the polarizer surface opposite to the surface on which the light is applied. That is, the polarizing plate 101A has a configuration in which the retardation film 105 according to the present invention is bonded to the polarizer 104 with the active energy ray-curable adhesive 103B.
- the retardation film 105 of the polarizing plate 101A is bonded to the liquid crystal cell 107 via an adhesive or an adhesive, and the liquid crystal cell surface (backlight) on the opposite side of the surface where the polarizing plate 101A and the liquid crystal cell 107 are bonded.
- Side: BL is described in the figure
- the retardation film 105 of the present invention of the polarizing plate 101B having the same configuration as the polarizing plate 101A is preferably bonded to constitute the liquid crystal display device 108.
- the polarizer which is the main component of the polarizing plate, is an element that passes only light having a plane of polarization in a certain direction
- a typical known polarizer is a polyvinyl alcohol polarizing film.
- the polyvinyl alcohol polarizing film includes those obtained by dyeing iodine on a polyvinyl alcohol film and those obtained by dyeing a dichroic dye.
- polarizer a polarizer obtained by forming a polyvinyl alcohol aqueous solution into a film and dyeing it by uniaxial stretching or dyeing and then uniaxially stretching and then preferably performing a durability treatment with a boron compound may be used.
- the film thickness of the polarizer is preferably in the range of 5 to 30 ⁇ m, particularly preferably in the range of 5 to 15 ⁇ m.
- the ethylene unit content described in JP-A-2003-248123, JP-A-2003-342322, etc. is 1 to 4 mol%
- the degree of polymerization is 2000 to 4000
- the degree of saponification is 99.0 to 99.99 mol. %
- Ethylene-modified polyvinyl alcohol is also preferably used.
- an ethylene-modified polyvinyl alcohol film having a hot water cutting temperature in the range of 66 to 73 ° C. is preferably used.
- a polarizer using this ethylene-modified polyvinyl alcohol film is excellent in polarization performance and durability, and has few color spots, and is particularly preferably used for a large-sized liquid crystal display device.
- ⁇ Protective film> In the polarizing plate according to the embodiment of the present invention, as shown in FIG. 2, an adhesive is further provided on the polarizer surface opposite to the surface on which the retardation film of the present invention is disposed, as necessary. It is preferable that the protective film 102 is laminated through the film.
- the protective film can be obtained as a commercial product.
- Konica Minolta Tac KC4UE, KC8UE, KC8UX, KC5UX, KC8UY, KC4UY, KC4CZ, KC6UA, KC4UA, and KC2UA (above, manufactured by Konica Minolta, Inc.) Can be mentioned.
- the protective film disposed on the viewing side is preferably provided with a functional layer such as a hard coat layer, an antistatic layer, an antireflection layer, a slippery layer, an adhesive layer, an antiglare layer, or a barrier layer.
- a functional layer such as a hard coat layer, an antistatic layer, an antireflection layer, a slippery layer, an adhesive layer, an antiglare layer, or a barrier layer.
- the retardation film 105 and the polarizer 104 are bonded via the adhesive 103A or 103B.
- an active energy ray-curable adhesive because moisture permeability can be effectively controlled.
- the adhesive is not particularly limited and is not limited to an active energy ray-curable adhesive, but also a urethane-based adhesive, an epoxy-based adhesive, an aqueous polymer-isocyanate-based adhesive, a thermosetting acrylic adhesive.
- Curing adhesives such as adhesives, moisture curing urethane adhesives, anaerobic adhesives such as polyether methacrylate type, ester methacrylate type, oxidized polyether methacrylate, cyanoacrylate instantaneous adhesives, acrylate and peroxide type 2
- a known adhesive such as a liquid instant adhesive can be used.
- the pressure-sensitive adhesive may be a one-component type or a two-component type in which two or more components are mixed before use.
- the adhesive may be a solvent system using an organic solvent as a medium, or may be an aqueous system such as an emulsion type, a colloidal dispersion type, or an aqueous solution type that is a medium containing water as a main component, or a solvent-free type. It may be a mold.
- concentration of the adhesive solution may be appropriately determined depending on the film thickness after bonding, the coating method, the coating conditions, and the like, and is usually 0.1 to 50% by mass.
- the protective film and the retardation film may be subjected to easy adhesion treatment on the adhesive surface with the polarizer, that is, the surface on which the adhesive is provided.
- the polarizer that is, the surface on which the adhesive is provided.
- the active energy ray-curable adhesive includes a cationic polymerization type and a radical polymerization type.
- Preferable examples of the active energy ray-curable adhesive that can be suitably used in the present invention include active energy ray-curable adhesive compositions containing the following components ( ⁇ ) to ( ⁇ ).
- ⁇ Cationic polymerizable compound
- ⁇ Photocationic polymerization initiator
- Photosensitizer exhibiting maximum absorption in light having a wavelength longer than 380 nm
- Naphthalene-based photosensitization aid Preferably, the compound is cationically polymerized by irradiation with active energy rays and cured to form an adhesive layer.
- the active energy ray-curable adhesive composition contains a photocationic polymerization initiator ( ⁇ ). Is preferred.
- the cationic photopolymerization initiator generates a cationic species or a Lewis acid by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, and electron beams, and initiates a polymerization reaction of the cationic polymerizable compound ( ⁇ ). It is.
- active energy ray ultraviolet rays are generally preferably used because it is easy to handle and has a sufficient curing rate.
- a preferable form of the ultraviolet curable adhesive will be briefly described.
- UV curable adhesive In one embodiment of the present invention, by applying an ultraviolet curable adhesive to bonding between the retardation film 105 and the polarizer 104 or bonding between the protective film 102 and the polarizer, high productivity can be achieved. The characteristics excellent in the durability of the polarizer can be obtained.
- composition of UV curable adhesive As the UV curable adhesive composition for polarizing plates, a photo radical polymerization composition using photo radical polymerization, a photo cation polymerization composition using photo cation polymerization, and photo radical polymerization and photo cation polymerization are used in combination. Hybrid type compositions are known.
- the radical photopolymerizable composition includes a radically polymerizable compound containing a polar group such as a hydroxy group and a carboxy group described in JP-A-2008-009329 and a radically polymerizable compound not containing a polar group at a specific ratio.
- Composition) and the like are known.
- the radical polymerizable compound is preferably a compound having a radical polymerizable ethylenically unsaturated bond.
- the compound having an ethylenically unsaturated bond capable of radical polymerization include a compound having a (meth) acryloyl group.
- Examples of the compound having a (meth) acryloyl group include an N-substituted (meth) acrylamide compound and a (meth) acrylate compound.
- (Meth) acrylamide means acrylamide or methacrylamide.
- cationic photopolymerization type composition as disclosed in JP2011-08234A, ( ⁇ ) a cationic polymerizable compound, ( ⁇ ) a cationic photopolymerization initiator, and ( ⁇ ) a wavelength longer than 380 nm.
- an ultraviolet curable adhesive composition containing each component of a photosensitizer exhibiting maximum absorption in the light of ( ⁇ ) and a naphthalene-based photosensitization aid.
- other ultraviolet curable adhesives may be used.
- another preferred embodiment of the present invention is a polarizing plate having at least one retardation film according to an embodiment of the present invention.
- the polarizing plate of the present invention can be suitably used for a liquid crystal display device. Since the liquid crystal display device using the polarizing plate of the present invention uses a retardation film having a low moisture permeability, color unevenness of the liquid crystal display device due to water content hardly occurs.
- the glass used for the panel of the liquid crystal display device preferably has a thickness in the range of 0.3 to 0.7 mm, and more preferably in the range of 0.3 to 0.5 mm. Since the polarizing plate of the present invention is not easily deformed, it is preferably used particularly when the glass thickness is small.
- Bonding between the surface of the polarizing plate of the present invention on the side of the retardation film and at least one surface of the liquid crystal cell can be performed by a known method. Depending on the case, it may be bonded through an adhesive layer.
- the mode (driving method) of the liquid crystal display device is not particularly limited, and liquid crystal display devices of various drive modes such as STN, TN, OCB, HAN, VA (MVA, PVA), IPS, OCB, and the like can be used.
- a VA (MVA, PVA) type (vertical alignment type) liquid crystal is used as an optical compensation retardation film (retardation film) that expands the viewing angle. It is suitably provided in a display device. That is, according to one embodiment of the present invention, there is provided a vertical alignment type liquid crystal display device in which the polarizing plate is provided on at least one surface of a liquid crystal cell.
- liquid crystal display device excellent in durability moisture and heat resistance
- another preferred embodiment of the present invention is a liquid crystal display device including a polarizing plate according to an embodiment of the present invention.
- a polarizing plate can be manufactured by bonding the retardation film of the present invention to one surface of a polarizer using an active energy ray-curable adhesive.
- the adhesiveness is different between both surfaces of the retardation film, it is preferable to bond the two on the one having better adhesiveness.
- the polarizing plate includes an adhesive application step of forming an adhesive layer by applying the following active energy ray-curable adhesive to at least one of the adhesive surfaces of the polarizer and the retardation film, and the adhesive layer A bonding step in which the polarizer and the retardation film are bonded and bonded via the adhesive layer, and a curing step in which the adhesive layer is cured in a state where the polarizer and the retardation film are bonded via the adhesive layer; It can manufacture with the manufacturing method containing. Moreover, there may be a pretreatment step in which the surface of the retardation film to which the polarizer is adhered is subjected to an easy adhesion treatment.
- a pre-processing process is a process of performing an easily bonding process to the adhesive surface of a cellulose-ester film with a polarizer.
- easy adhesion processing is performed on the bonding surfaces with the polarizer 104. Examples of the easy adhesion treatment include corona treatment and plasma treatment.
- the active energy ray curable adhesive is applied to at least one of the adhesive surfaces of the polarizer 104 and the retardation film 105.
- the application method is not particularly limited. For example, various wet coating methods such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater can be used.
- a method of casting an active energy ray-curable adhesive between a polarizer and a retardation film, and then pressurizing with a roll or the like to uniformly spread the active energy ray can be used.
- Bonding process After apply
- this bonding step for example, when an active energy ray-curable adhesive is applied to the surface of the polarizer 104 in the previous application step, the retardation film 105 is superimposed thereon.
- the polarizer 104 is superimposed thereon.
- an active energy ray-curable adhesive is cast between the polarizer 104 and the retardation film 105, the polarizer 104 and the retardation film 105 are overlaid in that state.
- the retardation film 105 or the protective film 102 is bonded to both sides of the polarizer and an active energy ray-curable adhesive is used on both sides, the active energy ray-curable adhesive is bonded to both sides of the polarizer 104, respectively.
- the retardation film 105 or the protective film 102 is overlaid through the agent.
- both sides when the retardation film 105 and the protective film 102 are superposed on one side of the polarizer, the retardation film 105 or the retardation film 105 or both sides of the polarizer,
- the protective films 102 are overlapped, the pressure is applied by sandwiching them with a pressure roller or the like from the retardation film or protective film side of both surfaces thereof.
- Metal, rubber, or the like can be used as the material of the pressure roller.
- the pressure rollers arranged on both sides may be made of the same material or different materials.
- an active energy ray curable adhesive is irradiated with active energy rays, and a cationic polymerizable compound (eg, epoxy compound or oxetane compound) or a radical polymerizable compound (eg, acrylate compound, acrylamide type).
- a cationic polymerizable compound eg, epoxy compound or oxetane compound
- a radical polymerizable compound eg, acrylate compound, acrylamide type.
- the retardation film 105 or the protective film 102 is bonded to both sides of the polarizer, the retardation film 105 or the protective film is overlaid on both sides of the polarizer via an active energy ray curable adhesive, respectively. It is advantageous to irradiate active energy rays and simultaneously cure the active energy ray-curable adhesive on both sides.
- active energy rays include X-rays, ultraviolet rays, electron beams, and visible rays.
- any appropriate conditions can be adopted as the ultraviolet irradiation conditions as long as the ultraviolet curable adhesive applied to the present invention can be cured.
- the dose of ultraviolet is 50 ⁇ 1500mJ / cm 2 in accumulated light quantity, and even more preferably 100 ⁇ 500mJ / cm 2.
- the irradiation condition of the electron beam is preferably 5 to 100 kGy, more preferably 10 to 75 kGy in terms of absorbed dose.
- the acceleration voltage is preferably 5 to 300 kV, and more preferably 10 to 250 kV.
- the line speed depends on the curing time of the adhesive, but is preferably 1 to 500 m / min, more preferably 5 to 300 m / min, and further preferably 10 to 100 m / min. is there. If the line speed is 1 m / min or more, productivity can be ensured, or damage to the retardation film can be suppressed, and a polarizing plate having excellent durability can be produced. Moreover, if the line speed is 500 m / min or less, the active energy ray-curable adhesive is sufficiently cured, and an active energy ray-curable adhesive layer having a desired hardness and excellent adhesiveness is formed. Can do.
- the thickness of the adhesive layer is not particularly limited, but is usually in the range of 0.01 to 10, and preferably in the range of 0.5 to 5 ⁇ m.
- composition of main dope solution The following components were sufficiently stirred and dissolved while heating to prepare a main dope solution.
- Cellulosic resin C1 (diacetyl cellulose having an acetyl group substitution degree of 2.41 and a weight average molecular weight (Mw) of 56,000): 100 parts by mass retardation increasing agent (nitrogen-containing compound (A) + nitrogen-containing compound (B)) : 3 parts by mass Sugar ester 1 (below): 10 parts by mass
- Aerosil R812 Manufacturing agent, manufactured by Nippon Aerosil Co., Ltd.
- 0.20 parts by mass Methylene chloride 300 parts by mass
- Ethanol 40 parts by mass
- the obtained dope was supported on a stainless steel band at a temperature of 22 ° C. and a width of 2 m using a belt casting apparatus. It was cast evenly on the body.
- the solvent was evaporated until the residual solvent amount was 30% by mass, and the film was peeled off from the stainless steel band support with a peeling tension of 162 N / m.
- the solvent of the peeled dope web is evaporated at 35 ° C., slitted, and then 1.1 in the fluent direction (MD direction) by zone stretching (a method of stretching in the longitudinal direction using a difference in roll peripheral speed).
- MD direction fluent direction
- zone stretching a method of stretching in the longitudinal direction using a difference in roll peripheral speed
- the film was dried at a drying temperature of 135 ° C. while being stretched 1.5 times in the width direction (TD direction) by tenter stretching.
- the residual solvent amount at the start of stretching by the tenter was 8%.
- Weight average molecular weight measurement The weight average molecular weight of the cellulose ester was measured using gel permeation chromatography. The measurement conditions are as follows.
- retardation films 102 to 110 In the production of the retardation film 101, the mass ratio of the nitrogen-containing compound (A) and the nitrogen-containing compound (B) contained in the retardation increasing agent is the ratio described in Table 1 (Table 1-1 and Table 1-2). Except for the above, retardation films 102 to 110 were produced in the same manner.
- retardation films 111 to 117 were produced in the same manner except that the compound 6 was used as the nitrogen-containing compound (A) and the compound 93 was used as the nitrogen-containing compound (B). .
- retardation films 118 to 124 were produced in the same manner except that the compound 41 was used as the nitrogen-containing compound (A) and the compound 151 was used as the nitrogen-containing compound (B). .
- retardation films 125 to 131 were produced in the same manner except that the compound 40 was used as the nitrogen-containing compound (A) and the compound 152 was used as the nitrogen-containing compound (B). .
- retardation films 132 to 138 were produced in the same manner except that the compound 42 was used as the nitrogen-containing compound (A) and the compound 154 was used as the nitrogen-containing compound (B). .
- retardation films 139 to 145 were similarly produced except that the compound 44 was used as the nitrogen-containing compound (A) and the compound 156 was used as the nitrogen-containing compound (B). .
- Retardation films 146 to 152 were produced in the same manner except that Compound 18 was used as Compound (A) and Compound 158 was used as Nitrogen-containing Compound (B) in the production of Retardation Films 104 to 110.
- retardation films 153 to 159 were produced in the same manner except that the compound 43 was used as the nitrogen-containing compound (A) and the compound 153 was used as the nitrogen-containing compound (B). .
- retardation films 160 to 166 were produced in the same manner except that the compound 45 was used as the nitrogen-containing compound (A) and the compound 155 was used as the nitrogen-containing compound (B). .
- retardation films 167 to 173 were produced in the same manner except that the compound 29 was used as the nitrogen-containing compound (A) and the compound 157 was used as the nitrogen-containing compound (B). .
- the produced retardation film is expressed by the following formula using an automatic birefringence meter Axoscan (Axo Scan Mueller Matrix Polarimeter: manufactured by Axometrics) at a wavelength of 590 nm in an environment of a temperature of 23 ° C. and a relative humidity of 55%.
- the retardation values Ro and Rt to be measured were measured.
- the retardation value Ro in the in-plane direction and the retardation value Rt in the thickness direction were calculated according to the following formula.
- n x represents a refractive index in the direction x in which the refractive index in the plane direction becomes maximum retardation films.
- n y in-plane direction of the retardation film, the refractive index in the direction y perpendicular to the direction x.
- n z represents the refractive index in the thickness direction z of the retardation film.
- d represents the thickness (nm) of the retardation film.
- the retardation of the retardation film was measured in an environment of 23 ° C. and relative humidity 55%.
- the retardation film was kept in a temperature of 60 ° C. and a relative humidity of 90% (humid heat environment) for 1000 hours, then transferred to an environment of 23 ° C. and a relative humidity of 55%, and kept for 24 hours. Thereafter, the retardation (Ro 2 , Rt 2 ) of the retardation film was measured in an environment of 23 ° C. and 55% relative humidity.
- phase difference measured values before and after maintaining the humid heat environment were compared, and the fluctuation rate was calculated.
- R O variation rate (%) and Rt variation rate (%) can be represented by the following formula (1) and (2).
- the wet heat durability of the retardation film was evaluated based on the following indicators.
- the fluctuation rate of Ro is ⁇ 2.5% and the fluctuation rate of Rt is within ⁇ 3.5%.
- the fluctuation rate of Ro is within ⁇ 3%, and the fluctuation rate of Rt is within ⁇ 4%.
- the fluctuation rate of Ro is ⁇ 4%, the fluctuation rate of Rt is within ⁇ 5% ... ⁇
- the rate of change of Ro is greater than 4%, the rate of change of Rt is greater than 5% ... ⁇ ⁇
- the obtained film was immersed in an aqueous solution consisting of 0.075 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds, and further immersed in an aqueous solution at 45 ° C. consisting of 3 g of potassium iodide, 7.5 g of boric acid and 100 g of water. .
- the obtained film was uniaxially stretched under conditions of a stretching temperature of 55 ° C. and a stretching ratio of 5 times. This uniaxially stretched film was washed with water and dried to obtain a polarizer having a thickness of 10 ⁇ m.
- a KC6UA film manufactured by Konica Minolta Co., Ltd.
- the active energy ray-curable adhesive (103A) was formed by coating so as to have a thickness of 5 ⁇ m.
- the prepared active energy ray-curable adhesive liquid is applied to the prepared retardation film 101 (105) so as to have a thickness of 5 ⁇ m, as described above, and the active energy ray-curable adhesive is thus prepared. (103B) was formed.
- the produced polyvinyl alcohol-iodine polarizer (104) is placed, and bonded by a roller machine, and the protective film (102) / A laminate in which active energy ray-curable adhesive (103A) / polarizer (104) / active energy ray-curable adhesive (103B) / retardation film 101 (105) was laminated was obtained. In that case, it bonded by the roller machine so that the slow axis of retardation film (105) and the absorption axis of polarizer (104) might become mutually orthogonal.
- the polarizing plate 101 (101A) was produced by irradiating an electron beam from both sides of the laminate.
- the line speed was 20 m / min
- the acceleration voltage was 250 kV
- the irradiation dose was 20 kGy.
- polarizing plates 102 to 110 were produced in the same manner except that the retardation film 101 was changed to the retardation films 102 to 110 in Table 1 (Table 1-1 and Table 1-2). .
- a liquid crystal display device provided with the polarizing plates 102 to 110 was produced in the same manner except that the polarizing plate 101 was changed to the polarizing plates 102 to 110.
- the prepared liquid crystal display device was laid and placed on a table or the like, and Bencot (registered trademark) (manufactured by Asahi Kasei Fibers Co., Ltd.) was placed on a part of the polarizing plate for evaluation to contain water.
- Bencot registered trademark
- the bencott registered trademark
- L * of the part where there was a becot was measured by EZ contrast (ELDIM) as L * of the water immersion part.
- L * of the part without Bencott (registered trademark) was measured by EZ contrast as L * of the non-immersed part.
- the measurement with EZ contrast was performed in the color mode with the TV displayed in black. The conditions for water immersion were such that the panel was turned on and left still for 24 hours with Bencot (registered trademark) sufficiently immersed in water. Subsequently, L * of the water-immersed part / L * of the non-immersed part was calculated, and color unevenness was evaluated according to the following criteria.
- the retardation film of the present invention containing the nitrogen-containing compound (A) and the nitrogen-containing compound (B) are retardation films of a comparative example (retardation film) comprising only one of the nitrogen-containing compound (A) and the nitrogen-containing compound (B).
- the polarizing plates (101 to 108) prepared using the retardation film produced by using the retardation increasing agent containing the nitrogen-containing compound (A) and the nitrogen-containing compound (B) according to the present invention include nitrogen-containing compounds (101 to 108). It was confirmed that the durability was high and display unevenness was small as compared with the polarizing plate (109, 110) prepared using the retardation film containing only one of A) and the nitrogen-containing compound (B). .
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Abstract
Description
で表される含窒素化合物(A)と、
下記一般式(2):
で表される含窒素化合物(B)と、
を含む位相差上昇剤を有する、位相差フィルムである。
で表される含窒素化合物(A)と、
下記一般式(2):
で表される含窒素化合物(B)と、
を含む位相差上昇剤を有する、位相差フィルムである。本発明によれば、高い位相差発現性と高い湿熱耐久性(湿熱環境下での位相差変動の抑制)を両立し得る位相差フィルムおよび、それを用いた偏光板、表示装置を提供できる。
本発明に係る位相差フィルムは、上記一般式(1)および(2)で表される含窒素化合物(A)および含窒素化合物(B)を含む位相差上昇剤を含む点を特徴とする。
位相差上昇剤(レターデーション発現剤ともいう)とは、位相差フィルムのレターデーション値を上昇させる機能を有する化合物をいう。具体的には、基材樹脂100質量部に対して化合物を3質量部含有した位相差フィルムの測定波長590nmにおける厚さ方向のレターデーション値Rt(590)が、未添加の位相差フィルムと比べて1.1倍以上の値を示す機能を有する化合物をいう。
下記一般式(1):
で表される含窒素化合物(A)と、
下記一般式(2):
で表される含窒素化合物(B)を含む。
本発明に係る位相差フィルムにおける含窒素化合物(A)および含窒素化合物(B)の合計の使用量は特に制限されない。ただし、所望のレターデーションを得るために、一般式(1)および(2)で表される化合物を、位相差フィルムの基材として用いるセルロースエステル等の樹脂100質量部に対して合計0.1~20質量部の範囲内で含有することが好ましく、1~15質量部の範囲内であることがより好ましく、1.5~10質量部の範囲内であることがさらに好ましく、2~8質量部の範囲内であることが一層好ましく、3~6質量部の範囲であることが特に好ましい。この範囲内であれば、本発明の位相差フィルムに十分なレターデーションを付与するとともに相溶性およびブリードアウト耐性が良好となる。
前記含窒素化合物(A)および含窒素化合物(B)は、公知の方法で合成することができる。含窒素化合物(A)において、1,2,4-トリアゾール環を有する化合物は、いかなる原料を用いても構わないが、ニトリル誘導体またはイミノエーテル誘導体と、ヒドラジド誘導体を反応させる方法が好ましい。反応に用いる溶媒としては、原料と反応しないと溶媒であれば、いかなる溶媒でも構わないが、エステル系(例えば、酢酸エチル、酢酸メチル等)、アミド系(ジメチルホルムアミド、ジメチルアセトアミド等)、エーテル系(エチレングリコールジメチルエーテル等)、アルコール系(例えば、メタノール、エタノール、プロパノール、イソプロパノール、n-ブタノール、2-ブタノール、エチレングリコール、エチレングリコールモノメチルエーテル等)、芳香族炭化水素系(例えば、トルエン、キシレン等)、水を挙げられることができる。使用する溶媒として、好ましくは、アルコール系溶媒である。また、これらの溶媒は、混合して用いても良い。
例示化合物1は以下のスキームによって合成することができる。
(例示化合物55の合成)
例示化合物55は以下のスキームによって合成することができる。
(例示化合物37の合成)
本発明に係る位相差フィルムは、基材樹脂として熱可塑性樹脂を含むことが好ましい。位相差フィルムに含まれる熱可塑性樹脂について特に制限はないが、好ましくは、基材層は延伸可能な熱可塑性樹脂から構成される。延伸可能な熱可塑性樹脂としては、例えば、アクリル系樹脂、スチレン系樹脂、シクロオレフィン系樹脂、セルロース系樹脂、ポリプロピレン系樹脂、ポリエステル系樹脂、またはこれらの組み合わせが挙げられる。この際、アクリル系樹脂としては、メチルメタクリレート由来の構成単位を主成分として含有し、これと共重合可能なモノマー成分由来の構成単位をさらに含むアクリル系樹脂が好ましく用いられる。共重合可能なモノマー成分としては、環構造を有するアクリル酸誘導体も含まれる。また、スチレン系樹脂としては、スチレン由来の構成単位を主成分として含有し、これと共重合可能なモノマー成分由来の構成単位をさらに含むスチレン系樹脂が挙げられる。さらに、シクロオレフィン系樹脂としては、シクロオレフィンコポリマーと称される、ノルボルネン系樹脂等が挙げられる。また、ポリプロピレン系樹脂としては、ポリプロピレンのほか、一部ポリエチレンを含むポリプロピレンなどが挙げられ、ポリエステル系樹脂としては、ポリエチレンテレフタレート(PET)などが挙げられる。
セルロースエステルのアシル基の種類および置換度を調節することによって上記Ro、Rt湿度変動を所望の範囲に制御することができ、膜厚の均一性を向上させることができる。
カラム: Shodex K806、K805、K803G(昭和電工株式会社製)を3本接続して使用する
カラム温度:25℃
試料濃度: 0.1質量%
検出器: RI Model 504(GLサイエンス株式会社製)
ポンプ: L6000(株式会社日立製作所製)
流量: 1.0ml/min
校正曲線: 標準ポリスチレンSTK standard ポリスチレン(東ソー株式会社製)Mw=1000000~500の13サンプルによる校正曲線を使用する。13サンプルは、ほぼ等間隔に用いる。
本発明に係る位相差フィルムは、その他の添加剤として上記の他に以下のものを含有していてもよい。
本発明の位相差フィルムは位相差フィルムに加工性を付与する目的で少なくとも1種の可塑剤を含むことが好ましい。可塑剤は単独でまたは2種以上混合して用いることが好ましい。
カラム: Shodex K806、K805、K803G(昭和電工株式会社製)を3本接続して使用する
カラム温度:25℃
試料濃度: 0.1質量%
検出器: RI Model 504(GLサイエンス株式会社製)
ポンプ: L6000(株式会社日立製作所製)
流量: 1.0ml/min
校正曲線: 標準ポリスチレンSTK standard ポリスチレン(東ソー株式会社製)Mw=1000000~500の13サンプルによる校正曲線を使用する。13サンプルは、ほぼ等間隔に用いる。
本発明に係る位相差フィルムには、加水分解防止を目的として、糖エステル化合物を含有させてもよい。具体的には、糖エステル化合物として、ピラノース構造またはフラノース構造の少なくとも1種を1個以上12個以下有しその構造のOH基の全て若しくは一部をエステル化した糖エステル化合物を使用することができる。
上記一般式(FA)で表される化合物は、平均置換度が3.0~6.0であることによって、透湿性の制御とセルロースエステルとの相溶性を高度に両立することができる。
1)LC部
装置:日本分光株式会社製カラムオーブン(JASCO(登録商標) CO-965)、ディテクター(JASCO(登録商標) UV-970-240nm)、ポンプ(JASCO(登録商標) PU-980)、デガッサー(JASCO(登録商標) DG-980-50)
カラム:Inertsil(登録商標) ODS-3 粒子径5μm 4.6×250mm(ジーエルサイエンス株式会社製)
カラム温度:40℃
流速:1ml/min
移動相:THF(1%酢酸):H2O(50:50)
注入量:3μl
2)MS部
装置:LCQ DECA(Thermo Quest株式会社製)
イオン化法:エレクトロスプレーイオン化(ESI)法
Spray Voltage:5kV
Capillary温度:180℃
Vaporizer温度:450℃。
本発明に係る位相差フィルムは、ポリエステル化合物を含有させることが好ましい。
B-(G-A)n-G-B
(式中、Bはヒドロキシ基またはカルボン酸残基を表し、Gは炭素数2~18のアルキレングリコール残基または炭素数6~12のアリールグリコール残基または炭素数が4~12のオキシアルキレングリコール残基を表し、Aは炭素数4~12のアルキレンジカルボン酸残基または炭素数6~12のアリールジカルボン酸残基を表し、nは1以上の整数を表す。)
一般式(FB)中、Bで示されるヒドロキシ基またはカルボン酸残基と、Gで示されるアルキレングリコール残基またはオキシアルキレングリコール残基またはアリールグリコール残基、Aで示されるアルキレンジカルボン酸残基またはアリールジカルボン酸残基とから構成されるものであり、通常のエステル系化合物と同様の反応により得られる。
本発明に係る位相差フィルムは、耐水性を目的として、アクリル系化合物を含有させることが好ましい。アクリル系化合物としては、特に制限されるものではないが、(メタ)アクリル酸、(メタ)アクリル酸エステル、(メタ)アクリルアミド類、および(メタ)アクリロニトリルよりなる群から選択されるいずれか少なくとも1種のアクリル系モノマー由来の繰り返し単位を有する重合体が挙げられる。
本発明に係る位相差フィルムには、上記糖エステル化合物、ポリエステル化合物、アクリル系化合物に加えてまたはこれに代えて、位相差フィルムの耐水性改善を目的として、スチレン系化合物を用いることもできる。
スチレン系化合物は、スチレン系モノマーの単独重合体であってもよいし、スチレン系モノマーとそれ以外の共重合モノマーとの共重合体であってもよい。スチレン系化合物におけるスチレン系モノマー由来の構成単位の含有割合は、分子構造が一定以上の嵩高さを有するためには、好ましくは30~100モル%、より好ましくは50~100モル%でありうる。
本発明に係る位相差フィルムには、上記糖エステル化合物、ポリエステル化合物、アクリル系化合物、およびスチレン系化合物に加えて、またはこれに替えて、分子量が15000以下、好ましくは10000以下の公知の可塑剤を用いることもできる。その他の可塑剤として特に限定されないが、好ましくは、多価カルボン酸エステル系可塑剤、グリコレート系可塑剤、フタル酸エステル系可塑剤、脂肪酸エステル系可塑剤および多価アルコールエステル系可塑剤などから選択される。中でも好適な可塑剤は、多価アルコールエステル系可塑剤である。
本発明に係る位相差フィルムは、湿度の変化に対する位相差変動を低減するために、水素結合性化合物を含有することが好ましい。
本発明に係る位相差フィルムは、酸化防止剤、着色剤、紫外線吸収剤、マット剤、アクリル粒子、水素結合性溶媒、イオン性界面活性剤などの他の任意成分を含みうる。これらの成分は、基材樹脂100質量部に対して0.01~20質量部の範囲で添加することができる。
本発明に係る位相差フィルムは、酸化防止剤としては、通常知られているものを使用することができる。特に、ラクトン系、イオウ系、フェノール系、二重結合系、ヒンダードアミン系、リン系の各化合物を好ましく用いることができる。
本発明の位相差フィルムは、本発明の効果を損なわない範囲内で、色味調整のために、着色剤を含むことが好ましい。着色剤というのは染料や顔料を意味し、本発明では、液晶画面の色調を青色調にする効果またはイエローインデックスの調整、ヘイズの低減を有するものを指す。
本発明の位相差フィルムは、偏光板の視認側やバックライト側に用いられることもできることから、紫外線吸収機能を付与することを目的として、紫外線吸収剤を含有してもよい。
本発明の位相差フィルムは、位相差フィルムの滑り性を付与する微粒子(マット剤)を添加することが好ましい。
本発明の位相差フィルムは、位相差フィルムの脆性を改善する目的で、国際公開第2010/001668号パンフレットに記載のアクリル粒子を、透明性を維持できる範囲内の量で含有してもよい。
本発明において、溶液流延法で位相差フィルムを作製する場合は、位相差フィルムの構成材料を溶解するための溶媒に、溶液粘度を調整(低減)する目的で、水素結合性溶媒を添加することができる。水素結合性溶媒とは、J.N.イスラエルアチビリ著、「分子間力と表面力」(近藤保、大島広行訳、マグロウヒル出版、1991年)に記載されるように、電気的に陰性な原子(酸素、窒素、フッ素、塩素)と電気的に陰性な原子と共有結合した水素原子間に生ずる、水素原子媒介「結合」を生ずることができるような有機溶媒、すなわち、結合モーメントが大きく、かつ水素を含む結合、例えば、O-H(酸素水素結合)、N-H(窒素水素結合)、F-H(フッ素水素結合)を含むことで近接した分子同士が配列できるような有機溶媒をいう。
本発明の位相差フィルムは、製膜時の剥離力を低下させる目的で、イオン性界面活性剤を添加することが好ましい。
次に、本発明の位相差フィルムの製造方法について説明する。本発明はこれに限定されるものではない。
溶液流涎法により製膜する場合、本発明の位相差フィルムの製造方法は、熱可塑性樹脂および上述した添加剤を溶媒に溶解させてドープを調製する工程(溶解工程;ドープ調製工程)、ドープを無限に移行する無端の金属支持体上に流延する工程(流延工程)、流延したドープをウェブとして乾燥する工程(溶媒蒸発工程)、金属支持体から剥離する工程(剥離工程)、乾燥、延伸、幅保持する工程(延伸・幅保持・乾燥工程)、仕上がった位相差フィルムを巻取る工程(巻き取り工程)を含むことが好ましい。熱可塑性樹脂としては、特にセルロースエステルを用いることが好ましい。
以下、本発明の一実施形態として、熱可塑性樹脂としてセルロースエステルを使用する場合を一例として溶解工程を説明するが、本発明はこれに限定されない。
続いて、ドープを金属支持体上に流延(キャスト)する。すなわち、本工程は、ドープを、送液ポンプ(例えば、加圧型定量ギヤポンプ)を通して加圧ダイ30に送液し、無限に移送する無端の金属ベルト31、例えばステンレスバンド、あるいは回転する金属ドラム等の金属支持体上の流延位置に、加圧ダイスリットからドープを流延する工程である。
本工程は、ウェブ(流延用支持体上にドープを流延し、形成されたドープ膜をウェブと呼ぶ)を流延用支持体上で加熱し、溶媒を蒸発させる工程である。
次いで、ウェブを金属支持体から剥離する。すなわち、本工程は金属支持体上で溶媒が蒸発したウェブを、剥離位置で剥離する工程である。剥離されたウェブは次工程に送られる。
(乾燥)
位相差フィルムの乾燥工程においては、ウェブを金属支持体より剥離し、更に乾燥し、残留溶媒量を1質量%以下にすることが好ましく、更に好ましくは0.1質量%以下であり、特に好ましくは0~0.01質量%以下である。
続いて、金属支持体より剥離したウェブを少なくとも一方向に延伸処理することが好ましい。延伸処理することで位相差フィルム内の分子の配向を制御することができる。本発明において目標とするレターデーション値Ro、Rtを得るには、位相差フィルムが本発明の構成をとり、更に搬送張力の制御、延伸操作により屈折率制御を行うことが好ましい。例えば、長手方向の張力を低くまたは高くすることでレターデーション値を変動させることが可能となる。
・流延方向に延伸→幅手方向に延伸→流延方向に延伸→流延方向に延伸
・幅手方向に延伸→幅手方向に延伸→流延方向に延伸→流延方向に延伸
また、同時2軸延伸には、一方向に延伸し、もう一方を、張力を緩和して収縮させる場合も含まれる。
最後に、得られたウェブ(仕上がった位相差フィルム)を巻取ることにより、位相差フィルムが得られる。より具体的には、ウェブ中の残留溶媒量が2質量%以下となってから位相差フィルムとして巻き取り機37により巻き取る工程であり、残留溶媒量を0.4質量%以下にすることにより寸法安定性の良好な位相差フィルムを得ることができる。特に0.00~0.10質量%の範囲で巻き取ることが好ましい。
また、本発明の位相差フィルムは、溶融流延法により製膜することもできる。
本発明の位相差フィルムが具備される偏光板および液晶表示装置の構成について、図面を参照して説明する。
本発明の一実施形態に係る偏光板は、少なくとも1つの本発明の一実施形態に係る位相差フィルム、および偏光子を必須に含む。
偏光板の主たる構成要素である偏光子は、一定方向の偏波面の光だけを通す素子であり、現在知られている代表的な偏光子は、ポリビニルアルコール系偏光フィルムである。ポリビニルアルコール系偏光フィルムには、ポリビニルアルコール系フィルムにヨウ素を染色させたものと、二色性染料を染色させたものとがある。
本発明の一実施形態に係る偏光板においては、必要に応じて、図2に示すように、本発明の位相差フィルムが配置されている面とは反対側の偏光子面に、更に接着剤を介して保護フィルム102が積層されていることが好ましい。
上述したように、図2に示す形態において、位相差フィルム105と偏光子104とは接着剤103Aまたは103Bを介して接着されている。活性エネルギー線硬化性接着剤を用いることが透湿性を効果的に制御できることから好ましい。ただし、本発明においては、接着剤は特に制限されず、活性エネルギー線硬化性接着剤のみならず、ウレタン系粘着剤、エポキシ系粘着剤、水性高分子-イソシアネート系粘着剤、熱硬化型アクリル粘着剤等の硬化型粘着剤、湿気硬化ウレタン粘着剤、ポリエーテルメタクリレート型、エステル系メタクリレート型、酸化型ポリエーテルメタクリレート等の嫌気性粘着剤、シアノアクリレート系の瞬間粘着剤、アクリレートとペルオキシド系の2液型瞬間粘着剤等の公知の接着剤を用いることができる。上記粘着剤としては1液型であってもよいし、使用前に2液以上を混合して使用する2液型であってもよい。接着剤は、有機溶媒を媒体とする溶媒系であってもよいし、水を主成分とする媒体であるエマルジョン型、コロイド分散液型、水溶液型等の水系であってもよいし、無溶媒型であってもよい。接着剤液の濃度は、接着後の膜厚、塗布方法、塗布条件等により適宜決定されれば良く、通常は0.1~50質量%である。
活性エネルギー線硬化性接着剤には、カチオン重合型とラジカル重合型がある。本発明に好適に用いることのできる活性エネルギー線硬化性接着剤の好ましい例には、以下の(α)~(δ)の各成分を含有する活性エネルギー線硬化性接着剤組成物が含まれる。
(β)光カチオン重合開始剤
(γ)380nmより長い波長の光に極大吸収を示す光増感剤
(δ)ナフタレン系光増感助剤
本発明では、カチオン重合性化合物を、活性エネルギー線の照射によってカチオン重合させて硬化させ、接着剤層を形成することが好ましく、活性エネルギー線硬化性接着剤組成物には、光カチオン重合開始剤(β)を配合することが好ましい。
本発明の一実施形態においては、位相差フィルム105と、偏光子104との貼合、あるいは保護フィルム102と偏光子との貼合に紫外線硬化型接着剤を適用することにより、高生産性で、偏光子の耐久性に優れた特性を得ることができる。
偏光板用の紫外線硬化型接着剤組成物としては、光ラジカル重合を利用した光ラジカル重合型組成物、光カチオン重合を利用した光カチオン重合型組成物、並びに光ラジカル重合及び光カチオン重合を併用したハイブリッド型組成物が知られている。
本発明の偏光板は、液晶表示装置に好適に用いることができる。本発明の偏光板が用いられた液晶表示装置は、透湿度の低い位相差フィルムが用いられていることから、含水による液晶表示装置の色ムラが発生しづらい。
偏光板は、活性エネルギー線硬化型接着剤を用いて、偏光子の一方の面に、本発明の位相差フィルムを貼り合せることにより製造することができる。位相差フィルムの両面で接着性が異なる場合は、接着性の良いほうに貼り合わせるのが好ましい。
前処理工程は、セルロースエステルフィルムの、偏光子との接着面に易接着処理を行う工程である。偏光子104の両面にそれぞれ位相差フィルム105および保護フィルム102を接着させる場合は、それぞれの、偏光子104との接着面に易接着処理を行う。易接着処理としては、コロナ処理、プラズマ処理等が挙げられる。
活性エネルギー線硬化性接着剤の塗布工程としては、偏光子104と位相差フィルム105との接着面のうち少なくとも一方に、上記活性エネルギー線硬化性接着剤を塗布する。偏光子104または位相差フィルム105の表面に直接、活性エネルギー線硬化性接着剤を塗布する場合、その塗布方法に特段の限定はない。例えば、ドクターブレード、ワイヤーバー、ダイコーター、カンマコーター、グラビアコーター等、種々の湿式塗布方式が利用できる。また、偏光子と位相差フィルムの間に、活性エネルギー線硬化性接着剤を流延させたのち、ロール等で加圧して均一に押し広げる方法も利用できる。
上記の方法により活性エネルギー線硬化性接着剤を塗布した後は、貼合工程で処理される。この貼合工程では、例えば、先の塗布工程で偏光子104の表面に活性エネルギー線硬化性接着剤を塗布した場合、そこに位相差フィルム105が重ね合わされる。先の塗布工程で、はじめに位相差フィルム105の表面に活性エネルギー線硬化性接着剤を塗布する方式の場合には、そこに偏光子104が重ね合わされる。また、偏光子104と位相差フィルム105の間に活性エネルギー線硬化性接着剤を流延させた場合は、その状態で偏光子104と位相差フィルム105とが重ね合わされる。偏光子の両面に、位相差フィルム105または保護フィルム102を接着する場合であって、両面とも活性エネルギー線硬化性接着剤を用いる場合は、偏光子104の両面にそれぞれ、活性エネルギー線硬化性接着剤を介して位相差フィルム105または保護フィルム102が重ね合わされる。そして、通常は、この状態で両面(偏光子の片面に位相差フィルム105および保護フィルム102を重ね合わせた場合は、偏光子側と位相差フィルム側、また偏光子の両面に位相差フィルム105または保護フィルム102を重ね合わせた場合は、その両面の位相差フィルムまたは保護フィルム側)から加圧ローラー等で挟んで加圧することになる。加圧ローラーの材質は、金属やゴム等を用いることが可能である。両面に配置される加圧ローラーは、同じ材質であってもよいし、異なる材質であってもよい。
硬化工程では、未硬化の活性エネルギー線硬化性接着剤に活性エネルギー線を照射して、カチオン重合性化合物(例えば、エポキシ化合物やオキセタン化合物)やラジカル重合性化合物(例えば、アクリレート系化合物、アクリルアミド系化合物等)を含む活性エネルギー線硬化性接着剤層を硬化させ、活性エネルギー線硬化性接着剤を介して重ね合わせた偏光子と位相差フィルム105とを接着させる。偏光子の片面に位相差フィルム105を貼合する場合、活性エネルギー線は、偏光子側又は位相差フィルム105側のいずれから照射してもよい。また、偏光子の両面に位相差フィルム105または保護フィルム102を貼合する場合、偏光子の両面にそれぞれ活性エネルギー線硬化性接着剤を介して位相差フィルム105または保護フィルムを重ね合わせた状態で、活性エネルギー線を照射し、両面の活性エネルギー線硬化性接着剤を同時に硬化させるのが有利である。
〔位相差フィルム101の作製〕
〈位相差上昇剤〉
化合物38(含窒素化合物(A))と化合物150(含窒素化合物(B))とを質量比99.9:0.1で混合した位相差上昇剤を使用した。
下記成分を加熱しながら十分に攪拌および溶解させて、主ドープ液を調製した。
位相差上昇剤(含窒素化合物(A)+含窒素化合物(B)):3質量部
糖エステル1(下記):10質量部
可塑剤1(フタル酸/アジピン酸/1,2-プロパンジオール=50/50/100モル比の縮合物の両末端を安息香酸エステル基で封止したもの、分子量440):2質量部
アエロジルR812(マット剤、日本アエロジル株式会社製):0.20質量部
メチレンクロライド:300質量部
エタノール:40質量部
得られたドープを、ベルト流延装置を用い、温度22℃、2m幅でステンレスバンド支持体に均一に流延した。ステンレスバンド支持体で、残留溶剤量が30質量%になるまで溶媒を蒸発させ、剥離張力162N/mでステンレスバンド支持体上から剥離した。次いで、剥離したドープのウェブを35℃で溶媒を蒸発させ、スリットし、その後、ゾーン延伸(ロール周速差を利用して縦方向に延伸する方法)で流涎方向(MD方向)に1.1倍、テンター延伸で幅手方向(TD方向)に1.5倍延伸しながら、135℃の乾燥温度で乾燥させた。テンターによる延伸を開始したときの残留溶媒量は8%であった。テンターで延伸した後、130℃で5分間の緩和処理を施した後、120℃、140℃の乾燥ゾーンを多数のローラーで搬送させながら乾燥を終了させ、1.5m幅にスリットし、位相差フィルム両端に幅10mm、高さ5μmのナーリング加工を施した後、コアに巻き取った。以上のようにして、乾燥膜厚35μmの位相差フィルム101を得た。
セルロースエステルの重量平均分子量の測定は、ゲルパーミエーションクロマトグラフィーを用いて測定した。測定条件は以下のとおりである。
カラム: Shodex K806,K805,K803G(昭和電工株式会社製)を3本接続して使用した
カラム温度:25℃
試料濃度: 0.1質量%
検出器: RI Model 504(GLサイエンス株式会社製)
ポンプ: L6000(株式会社日立製作所製)
流量: 1.0ml/min
校正曲線: 標準ポリスチレンSTK standard
ポリスチレン(東ソー株式会社製)Mw=1000000~500迄の13サンプルによる校正曲線を使用した。13サンプルは、ほぼ等間隔に用いる。
上記位相差フィルム101の作製において、位相差上昇剤に含まれる含窒素化合物(A)と含窒素化合物(B)の質量比を表1(表1-1および表1-2)に記載の割合としたこと以外は同様にして位相差フィルム102~110を作製した。
上記位相差フィルム101~110の作製において、含窒素化合物(A)として化合物6を使用し、含窒素化合物(B)として化合物93を使用した以外は同様にして位相差フィルム111~117を作製した。
上記位相差フィルム101~110の作製において、含窒素化合物(A)として化合物41を使用し、含窒素化合物(B)として化合物151を使用した以外は同様にして位相差フィルム118~124を作製した。
上記位相差フィルム101~110の作製において、含窒素化合物(A)として化合物40を使用し、含窒素化合物(B)として化合物152を使用した以外は同様にして位相差フィルム125~131を作製した。
上記位相差フィルム104~110の作製において、含窒素化合物(A)として化合物42を使用し、含窒素化合物(B)として化合物154を使用した以外は同様にして位相差フィルム132~138を作製した。
上記位相差フィルム104~110の作製において、含窒素化合物(A)として化合物44を使用し、含窒素化合物(B)として化合物156を使用した以外は同様にして位相差フィルム139~145を作製した。
上記位相差フィルム104~110の作製において、化合物(A)として化合物18を使用し、含窒素化合物(B)として化合物158を使用した以外は同様にして位相差フィルム146~152を作製した。
上記位相差フィルム104~110の作製において、含窒素化合物(A)として化合物43を使用し、含窒素化合物(B)として化合物153を使用した以外は同様にして位相差フィルム153~159を作製した。
上記位相差フィルム104~110の作製において、含窒素化合物(A)として化合物45を使用し、含窒素化合物(B)として化合物155を使用した以外は同様にして位相差フィルム160~166を作製した。
上記位相差フィルム104~110の作製において、含窒素化合物(A)として化合物29を使用し、含窒素化合物(B)として化合物157を使用した以外は同様にして位相差フィルム167~173を作製した。
上記作製した各位相差フィルムについて、下記の各特性値の測定および評価を行った。
作製した位相差フィルムについて、温度23℃、相対湿度55%の環境下で、波長590nmで、自動複屈折率計アクソスキャン(Axo Scan Mueller Matrix Polarimeter:アクソメトリックス社製)を用いて下記式で表されるレターデーション値Ro、Rtを測定した。
《位相差フィルムの位相差および湿熱耐久性の評価》
上記作製した各位相差フィルムについて、下記のように湿熱環境に保持する前後の位相差を測定し、位相差変動率を算出し、湿熱耐久性を評価した。
Roの変動率が±3%、Rtの変動率が±4%以内・・・○
Roの変動率が±4%、Rtの変動率が±5%以内・・・△
Roの変動率が4%より大きい、Rtの変動率が5%より大きい・・・×
《偏光板の作製》
〔偏光板101の作製〕
(偏光子の作製)
厚さ30μmのポリビニルアルコールフィルムを、35℃の水で膨潤させた。得られたフィルムを、ヨウ素0.075g、ヨウ化カリウム5gおよび水100gからなる水溶液に60秒間浸漬し、さらにヨウ化カリウム3g、ホウ酸7.5gおよび水100gからなる45℃の水溶液に浸漬した。得られたフィルムを、延伸温度55℃、延伸倍率5倍の条件で一軸延伸した。この一軸延伸フィルムを、水洗した後、乾燥させて、厚さ10μmの偏光子を得た。
下記の各成分を混合した後、脱泡して、活性エネルギー線硬化性接着剤液を調製した。なお、トリアリールスルホニウムヘキサフルオロホスフェートは、50%プロピレンカーボネート溶液として配合し、下記にはトリアリールスルホニウムヘキサフルオロホスフェートの固形分量を表示した。
・エポリード(登録商標)GT-301(ダイセル化学工業株式会社製の脂環式エポキシ樹脂) 40質量部
・1,4-ブタンジオールジグリシジルエーテル 15質量部
・トリアリールスルホニウムヘキサフルオロホスフェート 2.3質量部
・9,10-ジブトキシアントラセン 0.1質量部
・1,4-ジエトキシナフタレン 2.0質量部
(偏光板101の作製)
下記の方法に従って、図2の偏光板101Aの構成からなる偏光板101を作製した。カッコ内の数値は、図2に記載した各構成要素の番号を示す。
偏光板101の作製において、位相差フィルム101を表1(表1-1および表1-2)の位相差フィルム102~110に変更したこと以外は同様にして、偏光板102~110を作製した。
SONY(ソニー株式会社)製40型ディスプレイBRAVIA(登録商標) X1のあらかじめ貼合されていた両面の偏光板を剥がして、上記作製した偏光板101を液晶セルのガラス面の両面に、貼合した。その際、その偏光板の貼合の向きは、位相差フィルム101の面が、液晶セル側となるように、かつ、あらかじめ貼合されていた偏光板と同一の方向に吸収軸が向くように行った。これより、偏光板101を備えた液晶表示装置を作製した。
上記作製した各液晶表示装置およびその作製に用いた各偏光板について、下記の各評価を行った。
上記作製した液晶表示装置を寝かせて台の上などに置き、ベンコット(登録商標)(旭化成せんい株式会社製)を評価用偏光板の一部に載せて水を含ませた。ベンコット(登録商標)が乾かないよう100μmPETで覆い、テレビにPCから黒表示の信号を入力、テレビの電源ONで24時間放置した(室温は23℃に設定、パネル温度は38℃)。24時間後、ベンコット(登録商標)を取り除く。ベンコットのあった部分のL*を水浸漬部のL*としてEZコントラスト(ELDIM社製)で測定した。ベンコット(登録商標)のない部分のL*を非浸漬部のL*としてEZコントラストで測定した。なお、EZコントラストでの測定はTVを黒表示にしてカラーモードにて行った。水浸漬の条件はパネルの電源をONにし、かつ水を十分に浸み込ませたベンコット(登録商標)を貼り付けた状態で24時間静置する条件とした。次いで、水浸漬部のL*/非浸漬部のL*を算出し、下記の基準に従って色ムラの評価を行った。
○:1.30超1.55以下:僅かに弱い色ムラの発生が認められるが、実用上問題のない品質である
△:1.55超1.80以下:色ムラの発生が認められ、実用上問題がある
×:1.80超、1.05未満:強い色ムラが発生し、耐湿性に問題のある品質である
(表示ムラの評価)
上記作製した各液晶表示装置を、40℃、90%RHの環境下で、400時間連続点灯した後、画面の表示ムラ(輝度ムラ)、スジムラの有無を目視観察し、下記の基準に従って、表示ムラの評価を行った。
○:表示ムラ、輝度ムラの発生がほぼ認められない
△:ごく弱い表示ムラ、輝度ムラの発生は認められるが、画像表示で気にならなく、実用上は許容される範囲にある
×:強い表示ムラ、輝度ムラの発生は認められ、実用上問題となる品質である
位相差フィルムの構成内容および上記評価の結果を、下記表2にまとめて示す。
Claims (6)
- 位相差上昇剤中の、含窒素化合物(A)と含窒素化合物(B)との含有比率は、含窒素化合物(A)と含窒素化合物(B)の質量の合計を100としたとき、含窒素化合物(A):含窒素化合物(B)=2:98~98:2である、請求項1に記載の位相差フィルム。
- 上記一般式(1)で表される含窒素化合物の中の含窒素芳香族複素環構造X2、Y2、上記一般式(2)で表される含窒素化合物の中の含窒素芳香族複素環構造X3、Y3、Z3が、それぞれ独立して、イミダゾール環、ピラゾール環、またはトリアゾール環からなる群から選択される含窒素芳香族複素環である、請求項1または2に記載の位相差フィルム。
- セルロース系樹脂を主成分とする、請求項1~3のいずれか1項に記載の位相差フィルム。
- 請求項1~4のいずれか1項に記載の位相差フィルムを少なくとも1つ有する偏光板。
- 請求項5に記載の偏光板を備える液晶表示装置。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
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JP2016510220A JP6627748B2 (ja) | 2014-03-25 | 2015-03-12 | 位相差フィルムおよび、それを用いた偏光板、表示装置 |
CN201580015601.2A CN106104333B (zh) | 2014-03-25 | 2015-03-12 | 相位差膜及使用该相位差膜的偏振片、显示装置 |
KR1020167025976A KR20160124867A (ko) | 2014-03-25 | 2015-03-12 | 위상차 필름 및 그것을 사용한 편광판, 표시 장치 |
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Cited By (2)
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WO2018212112A1 (ja) * | 2017-05-16 | 2018-11-22 | 日東電工株式会社 | 円偏光フィルム、粘着剤層付円偏光フィルムおよび画像表示装置 |
JP2019019274A (ja) * | 2017-07-20 | 2019-02-07 | 富士ゼロックス株式会社 | 樹脂組成物及び成形体 |
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Also Published As
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KR20160124867A (ko) | 2016-10-28 |
CN106104333B (zh) | 2018-11-13 |
JPWO2015146599A1 (ja) | 2017-04-13 |
JP6627748B2 (ja) | 2020-01-08 |
CN106104333A (zh) | 2016-11-09 |
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