CN101669049B

CN101669049B - Optical compensation films, optically compensating film, and processes for producing these

Info

Publication number: CN101669049B
Application number: CN200880012534.9A
Authority: CN
Inventors: 土井亨; 丰增信之; 尾崎想; 下里伸治
Original assignee: Tosoh Corp
Current assignee: Tosoh Corp
Priority date: 2007-04-18
Filing date: 2008-04-17
Publication date: 2013-10-30
Anticipated expiration: 2028-04-17
Also published as: JP2008287226A; CN101669049A; JP5407159B2

Abstract

Optical compensation films which have an optically compensating function imparted thereto by uniaxial stretching conducted during or after application and which are reduced in the wavelength dependence of retardation. One of the optical compensation films comprises a coating film made of a maleimide resin, and is characterized in that when any two axes perpendicularly crossing within the plane of the coating film are taken as x-axis and y-axis, respectively, an out-of-plane direction perpendicularly crossing that direction is taken as z-axis, and the refractive indices in the x-axis direction, y-axis direction, and z-axis direction are expressed by nx, ny, and nz, respectively, then the three-dimensional refractive indices satisfy the relationship nx'ny>nz. Also provided is an optically compensating film characterized by comprising a coating film layer (A) made of a maleimide resin and a stretched film layer (B). Another optical compensation film is one obtained by uniaxially stretching a coating film made of a maleimide resin, characterized in that when an axis in the stretch direction for the coating film is taken as x-axis, an in-plane direction and an out-of-plane direction which perpendicularly cross that direction are taken as y-axis and z-axis, respectively, and the refractive indices in the x-axis direction, y-axis direction, and z-axis direction are expressed by nx4, ny4, and nz4, respectively, then the three-dimensional refractive indices satisfy the relationship nx4>ny4>nz4. [Chemical formula 1] (1) (In the formula, R1 represents C1-18 linear alkyl, branched alkyl, cycloalkyl, a halogen-containing group, or an ether, ester, or amide group).

Description

Optical compensating layer, optical compensation films and their manufacture method

Technical field

The present invention relates to optical compensating layer and optical compensation films.More specifically, also have the optical compensating layer of optical compensation function and optical compensation films, and their manufacture method even the present invention relates to when being in unstretched state or uniaxial tension state for liquid crystal display cells and at the coating caudacoria of coating fluid.

Background technology

Liquid crystal display is most important display in the multimedia society, and be widely used in from the portable phone to the computer monitor, in the application of subnotebook PC and TV.Many bloomings are used for liquid crystal display to improve display characteristic.

Especially, from the front or vergence direction watch in the situation of display, optical compensation films plays an important role at aspects such as contrast improvement, tone compensation.So far the optical compensation films that has used is the stretched film of polycarbonate, cyclic polyolefin or celluosic resin.But these films have for example following problem: biaxial stretch-formed step is necessary and carries out biaxial stretch-formed step is difficult with the homogeneity that obtains to postpone.And particularly in having large-area film, it is more difficult regulating by biaxial stretch-formed delay of giving.

As the technology of be used for eliminating with biaxial stretch-formed relevant those problems, just at the Optical layer of compensation, it forms by the coating (coating) that is coated with fluid and demonstrate optical compensation function under the state of not stretching.

The Harris of University Of Akron and Cheng have proposed the optical compensating layer (referring to for example patent documentation 1 and 2) by the polyimide of rigid rod, polyester, polyamide, poly-(amide-imide) or poly-(ester-acid imide) formation.These materials have the character of spontaneously carrying out molecular orientation, and are characterised in that therefore the coating by the coating fluid demonstrates delay without stretching step.

And, the optical compensating layer (referring to such as patent documentation 3) that the polyimide by the coating fluid coating (dissolubility in solvent) with improvement forms, the polaroid (referring to such as patent documentation 4) with the diaphragm that is coated with the disc-like liquid crystal compound etc. have been proposed.

The stretched film (referring to for example patent documentation 5) made by phenyl maleimide/isobutylene copolymers has also been proposed.

Patent documentation 1: U.S. Patent No. 5,344,916

Patent documentation 2:JP-T-10-508048

Patent documentation 3:JP-A-2005-070745

Patent documentation 4: Jap.P. No.2565644

Patent documentation 5:JP-A-2004-269842

Summary of the invention

Problem to be solved by this invention

But the wavelength dependence of the delay of the polymkeric substance that obtains by the method that proposes in patent documentation 1-3 is strong, because they are aromatic polymers.When being used as the optical compensating layer of liquid crystal display cells, these polymkeric substance cause the problem about image quality decrease, such as gamut.

The technology of wherein using the disc-like liquid crystal compound that proposes in patent documentation 4 has for example following problem: must make the even orientation of liquid-crystal compounds and this so that coating process is complicated, and the orientation unevenness strengthens.In addition, because this liquid-crystal compounds also mainly is aromatic compounds, so this technology also has the strong quality problems of wavelength dependence of delay.

The stretched film that obtains according to patent documentation 5 is when state that the coating that only is in by the coating fluid forms, and this film does not demonstrate delay (nx=ny=nz).For its three-dimensional refractive index after stretching, nz4 is the highest.

Therefore, the purpose of this invention is to provide optical compensating layer and the optical compensation films with excellent optical.More specifically, described purpose provides and has when the coating of coating fluid or during at the coating coating of fluid and uniaxial tension subsequently and give its optical compensation function and optical compensating layer and the optical compensation films a little less than the wavelength dependence of its delay.

The means of dealing with problems

Because these problems, the inventor is studied assiduously.The result, they find: the coating layer that is formed by maleimide resin, the coating layer that obtains by this coating layer of uniaxial tension or the optical compensation films that comprises maleimide resin can be the film with optical compensation function, particularly are suitable for application type optical compensating layer or the optical compensation films of the optical compensation in the liquid crystal display cells.Finished thus the present invention.

Namely, the invention provides: optical compensating layer, wherein this layer of compensation is the coating layer that comprises maleimide resin, wherein ought in the plane of coating layer, be called respectively x axle and y axle by orthogonal two arbitrary axis, and when direction is called the z axle outside the plane, coating layer capable of meeting requirements on three-dimensional index of refraction relationship nx ≈ ny＞nz so, wherein nx is the refractive index on the x direction of principal axis, ny is the refractive index on the y direction of principal axis, and nz is the refractive index on the z direction of principal axis; Optical compensation films, it comprises coating layer (A) and the stretch film layers (B) that comprises maleimide resin; And optical compensating layer, it is to comprise the optical compensating layer that the coating layer of maleimide resin obtains by uniaxial tension, wherein the tensile axis direction in coating layer is called the x4 axle, the direction vertical with this draw direction is called the y4 axle, and when direction is called the z4 axle outside the plane, optical compensating layer capable of meeting requirements on three-dimensional index of refraction relationship nx4＞ny4＞nz4 so, wherein nx4 is the refractive index on the x4 direction of principal axis, ny4 is the refractive index on the y4 direction of principal axis, and nz4 is the refractive index on the z4 direction of principal axis.

Effect of the present invention

Optical compensating layer of the present invention and optical compensation films can be made in the optical compensation function of easily regulating them.Therefore they can be used as the effective contrast of the liquid crystal display cells liquid crystal TV of VA work pattern (particularly with) and optical compensating layer and optical compensation films of viewing angle characteristic of improving.

Embodiment

The below will describe the present invention in detail.

Optical compensating layer is provided explanation, it is characterized in that: it is the coating layer that comprises maleimide resin, orthogonal two arbitrary axis are called respectively x axle and y axle in the plane of coating layer with working as, and when direction is called the z axle outside the plane, coating layer capable of meeting requirements on three-dimensional index of refraction relationship nx ≈ ny＞nz so, wherein nx is the refractive index on the x direction of principal axis, and ny is the refractive index on the y direction of principal axis, and nz is the refractive index on the z direction of principal axis.

The example of maleimide resin comprises the polymer maleimides resin of N-replacement and the maleimide that N-replaces-copolymer-maleic anhydride resin.The example of the maleimide residue unit that the N-of formation maleimide resin replaces comprises the residue unit by the maleimide of the N-replacement of following general formula (1) expression.

[changing 1]

(R wherein ₁Expression has straight chained alkyl, branched alkyl or the naphthenic base of 1-18 carbon atom, halogen group, ether, ester group or amide group).

The instantiation of the maleimide residue unit that N-replaces comprises and is selected from following one or more: N-methyl maleimide residue unit, NEM residue unit, N-chloroethyl maleimide residue unit, N-methoxyethyl maleimide residue unit, N-n-pro-pyl maleimide residue unit, N-isopropyl maleimide residue unit, N-normal-butyl maleimide residue unit, N-isobutyl maleimide residue unit, N-sec-butyl maleimide residue unit, N-tert-butyl group maleimide residue unit, N-hexyl maleimide residue unit, N-N-cyclohexylmaleimide residue unit, N-octyl group maleimide residue unit, N-lauryl maleimide residue unit etc.Particularly preferably be N-normal-butyl maleimide residue unit, N-isobutyl maleimide residue unit, N-sec-butyl maleimide residue unit, N-tert-butyl group maleimide residue unit, N-hexyl maleimide residue unit and N-octyl group maleimide residue unit.Therefore these unit provide the maleimide resin that is easy to demonstrate delay and the dissolubility in solvent and physical strength excellence.

The example of the polymer maleimides resin that N-replaces comprises N-methyl polymer maleimides resin, the NEM fluoropolymer resin, N-chloroethyl polymer maleimides resin, N-methoxyethyl polymer maleimides resin, N-n-pro-pyl polymer maleimides resin, N-isopropyl polymer maleimides resin, N-normal-butyl polymer maleimides resin, N-isobutyl polymer maleimides resin, N-sec-butyl polymer maleimides resin, N-tert-butyl group polymer maleimides resin, N-hexyl polymer maleimides resin, N-N-cyclohexylmaleimide fluoropolymer resin, N-octyl group polymer maleimides resin and N-lauryl polymer maleimides resin.

The example of the maleimide that N-replaces-copolymer-maleic anhydride resin comprises N-methyl maleimide-copolymer-maleic anhydride resin, NEM-copolymer-maleic anhydride resin, N-chloroethyl maleimide-copolymer-maleic anhydride resin, N-methoxyethyl maleimide-copolymer-maleic anhydride resin, N-n-pro-pyl maleimide-copolymer-maleic anhydride resin, N-isopropyl maleimide-copolymer-maleic anhydride resin, N-normal-butyl maleimide-copolymer-maleic anhydride resin, N-isobutyl maleimide-copolymer-maleic anhydride resin, N-sec-butyl maleimide-copolymer-maleic anhydride resin, N-tert-butyl group maleimide-copolymer-maleic anhydride resin, N-hexyl maleimide-copolymer-maleic anhydride resin, N-N-cyclohexylmaleimide-copolymer-maleic anhydride resin, N-octyl group maleimide-copolymer-maleic anhydride resin and N-lauryl maleimide-copolymer-maleic anhydride resin.

Particularly preferably be N-normal-butyl polymer maleimides resin, N-hexyl polymer maleimides resin, N-octyl group polymer maleimides resin and N-octyl group maleimide-copolymer-maleic anhydride resin in these.Therefore these resins have excellent film-forming quality and are being given in optical compensation function and the optical compensating layer of thermotolerance aspect excellence aspect the formation of layer.

The maleimide resin that consists of this optical compensating layer of the present invention can comprise and is different from maleimide residue unit that N-replaces and the residue unit of maleic anhydride residue unit, as long as this does not deviate from purpose of the present invention.The example of this optional residue unit comprises following one or more: distyryl compound residue unit such as styrene residue unit and α-methyl styrene residue unit; Acrylic acid residue unit; Acrylate residue unit such as methyl acrylate residue unit, ethyl acrylate residue unit and butyl acrylate residue unit; Methacrylic acid residue unit; Methacrylate residue unit such as methyl methacrylate residue unit, β-dimethyl-aminoethylmethacrylate residue unit and butyl methacrylate residue unit; Vinyl esters residue such as vinyl acetate residue, propionate residue, new vinyl acetate acid residue, vinyl laurate residue and stearic acid vinyl ester residue; The vinyl cyanide residue; Methacrylonitrile residue etc.

Preferably, maleimide resin should be the number-average molecular weight (Mn) calculated take polystyrene standard by the elution curve that obtains in the gel permeation chromatography (hereinafter being called GPC) as 1 * 10 ³Or higher resin.Its number-average molecular weight is particularly preferably 2 * 10 ⁴To 2 * 10 ⁵, because this maleimide resin provides the optical compensating layer that has excellent mechanical properties and have excellent formability in the formation of layer.

In order to make the maleimide resin that consists of this optical compensating layer of the present invention, can use any means, as long as obtain this maleimide resin.For example, this resin can be manufactured by the following: but maleimide and maleic anhydride that at least a N-is replaced randomly carry out free radical polymerization or free-radical polymerized with one or more monomers with the maleimide copolymerization of N-replacement.The example of the maleimide that N-replaces comprises following one or more: N-methyl maleimide, NEM, N-chloroethyl maleimide, N-methoxyethyl maleimide, N-n-pro-pyl maleimide, N-isopropyl maleimide, N-normal-butyl maleimide, N-isobutyl maleimide, N-sec-butyl maleimide, N-tert-butyl group maleimide, N-hexyl maleimide, the N-N-cyclohexylmaleimide, N-octyl group maleimide etc.The example of described copolymerisable monomer comprises following one or more: distyryl compound such as styrene and α-methyl styrene; Acrylic acid; Acrylate such as methyl acrylate, ethyl acrylate and butyl acrylate; Methacrylic acid; Methacrylate such as methyl methacrylate, β-dimethyl-aminoethylmethacrylate and butyl methacrylate; Vinyl esters such as vinyl acetate, propionate, new vinyl acetate acid, vinyl laurate and stearic acid vinyl ester; Vinyl cyanide; Methacrylonitrile etc.

Can use known polymerization technique to carry out free radical polymerization.For example, can use all polymerization techniques such as bulk polymerization, solution polymerization, suspension polymerization, precipitation polymerization and emulsion polymerization.

The example of available polymerization initiator comprises organic peroxide such as benzoyl peroxide, lauryl peroxide, peroxidating decoyl, acetyl peroxide, di-tert-butyl peroxide, tert-butyl group cumyl peroxide, dicumyl peroxide, tert-butyl peroxy acetate and t-butyl peroxybenzoate in the situation of carrying out free radical polymerization; With azo initiator such as 2,2 '-azo two (2,4-methyl pentane nitrile), 2,2 '-azo two (2-butyronitrile), 2,2 '-azoisobutyronitrile, 2,2 '-azo-bis-iso-dimethyl and 1,1 '-azo two (cyclohexane-1-nitrile).

Be no particular limitation in solvent available in solution polymerization, suspension polymerization, precipitation polymerization and the emulsion polymerization.The example comprises arsol such as benzene, toluene and dimethylbenzene; Alcoholic solvent such as methyl alcohol, ethanol, propyl alcohol and butanols; Cyclohexane; Diox; Tetrahydrofuran (THF); Acetone; MEK; Dimethyl formamide; Isopropyl acetate; Water; And 1-METHYLPYRROLIDONE.The example also comprises two or more mixed solvents that consist of by these.

Polymerization temperature in the situation of carrying out free radical polymerization can suitably be set according to the decomposition temperature of polymerization initiator.Usually, preferably under 40-150 ℃ temperature, carry out polymerization.

This optical compensating layer of the present invention is the coating layer that comprises maleimide resin, and particularly excellent at optical compensation function when the optical compensating layer.The film of being made by polymkeric substance therein is used as in the situation of optical compensation films, and the three-dimensional refractive index of this film is usually by for example biaxial stretch-formed adjusting of film.But biaxial stretch-formed step has for example problem of manufacturing step and quality control complicated.On the contrary, optical compensating layer of the present invention is the coating layer that comprises maleimide, and for to be characterised in that following optical compensating layer: orthogonal two arbitrary axis are called respectively x axle and y axle in the plane at coating layer, and when direction is called the z axle outside the plane, coating layer capable of meeting requirements on three-dimensional index of refraction relationship nx ≈ ny＞nz so, wherein nx is the refractive index on the x direction of principal axis, ny is that refractive index on the y direction of principal axis is (when nx is not equal to ny, minimum refractive index is as nx), and nz is the refractive index on the z direction of principal axis.Found that this layer shows this layer of being in unstretched state and have idiosyncratic behavior than low-refraction at the thickness direction of layer.

The thickness direction retardation of this optical compensating layer of the present invention (Rth) can by change comprise maleimide coating layer thickness and easily regulate.With the light measurement of the measurement wavelength with 589nm and by its plane external delays (Rth) of following formula (2) expression preferably in the 30-2000nm scope, because this optical compensating layer can estimate to be suitable for use as phase shift films.Especially, its delay (Rth) is at preferred 50-1000nm, more preferably in the scope of 80-500nm, because this optical compensating layer has the excellent effect of the viewing angle characteristic that improves liquid crystal display cells.

Rth＝((nx+ny)/2-nz)×d (2)

(in expression formula (2), d represents the thickness (nm) of optical compensating layer).

Preferably, this optical compensating layer of the present invention should be the weak layer of wavelength dependence of delay, because use this optical compensating layer so that liquid crystal display cells can reduce at gamut in liquid crystal display cells.Especially, the wavelength dependence of its delay (R450/R589) is preferably 1.1 or less, particularly 1.08 or less, the wavelength dependence of this delay (R450/R589) by the delay (R450) of the coating layer that tilts 40 degree and detect with the light of the measurement wavelength with 450nm with tilt 40 degree and represent with the ratio of the delay (R589) of the coating layer of the light detection of the measurement wavelength with 589nm.

Preferably, the transmittance of measuring according to JIS K 7361-1 (version in 1997) of this optical compensating layer of the present invention is 85% or higher, particularly 90% or higher, because this optical compensating layer is given gratifying picture quality when being used for liquid crystal display cells.Also preferred, the mist degree of the optical compensating layer of measuring according to JIS K 7136 (version in 2000) is 2% or lower, particularly 1% or lower.

From the viewpoint of the quality stability liquid crystal display cells, optical compensating layer of the present invention preferably has high thermotolerance.Its glass transition temperature is preferably 100 ℃ or higher, and particularly preferably 120 ℃ or higher, even more preferably 135 ℃ or higher.

Optical compensating layer of the present invention is characterised in that to be the coating layer that comprises maleimide resin.Comprise wherein the suprabasil method of film that maleimide resin with solution state is coated in glass substrate or (PET) etc. is made by triacetyl cellulose, poly-(ethylene glycol terephthalate) for the manufacture of the example of the method for optimizing of this layer.For coating, can use the method that wherein will be coated on glass substrate or the film and pass through afterwards the desolventizings such as heating by maleimide resin being dissolved in the solution for preparing in the solvent.As the technology that be used for to apply, use such as scraping the skill in using a kitchen knife in cookery, rod and be coated with method, intaglio plate rubbing method, groove crack mould rubbing method, lip die head rubbing method (lip coater method), rubbing method (comma coater method) etc. intermittently.Industrial, the intaglio plate rubbing method and intermittently rubbing method be generally used for respectively thin coating and thick coating.Employed solvent is especially restriction not.The example comprises arsol such as toluene, dimethylbenzene, chlorobenzene and nitrobenzene; Ketone solvent such as acetone, MEK, methyl isobutyl ketone and cyclohexanone; Ether solvents such as dimethyl ether, diethyl ether, methyl tert-butyl ether, tetrahydrofuran He diox; Acetic acid esters solvent such as methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate and butyl acetate; Hydrocarbon solvent such as hexane, cyclohexane, octane and decane; Alcoholic solvent such as methyl alcohol, ethanol, propyl alcohol and butanols; Chlorine compound solvent such as phenixin, chloroform, methylene chloride, ethylene dichloride and trichloroethanes; Amide solvent such as dimethyl formamide and dimethyl acetamide; And 1-METHYLPYRROLIDONE.Can use two or more combination of these solvents.In solution applied, preferably the viscosity with solution was adjusted to 10-10000cp, 10-5000cp particularly because from this solution obtain having high transparent easilier, the optical compensating layer of thickness accuracy and surface smoothness excellence.

The thickness of the maleimide resin that will apply in this operation is determined by the thickness direction retardation of coating layer.Especially, from obtaining excellent surface smoothness and improve the viewpoint of the excellent effect of viewing angle characteristic, at preferred 1-100 μ m, more preferably 3-50 μ m is particularly preferably in the scope of 5-30 μ m at dried thickness for it.

This optical compensating layer of the present invention can be to use after glass substrate or other blooming are peeled off from substrate, can comprise that maybe described substrate is that the form of the stratiform product of glass substrate or other blooming is used.Especially, therein optical compensating layer be formed on the other blooming and this stratiform product as in the situation of optical compensation films, described other blooming is preferably the film of being made by celluosic resin, and particularly preferably be the film of being made by triacetyl cellulose, because this blooming is excellent aspect the transparency, intensity and adhesion.

This optical compensating layer of the present invention also can be used as the stratiform product that comprises polaroid and uses.Antioxidant can be introduced in the optical compensating layer of the present invention to strengthen thermal stability.The example of antioxidant comprises hindered phenol antioxidant, phosphorus compound antioxidant and other antioxidant.These antioxidants can be used alone or in combination.Preferably hindered phenol antioxidant and phosphorus compound antioxidant combination are used, because these antioxidants are realized the function of the anti-oxidation improved synergistically.In this case, particularly preferably 100-500 weight portion phosphorus compound antioxidant is mixed with 100 weight portion hindered phenol antioxidant.For the amount of antioxidant to be added, consist of the maleimide resin of optical compensating layer of the present invention for per 100 weight portions, this amount is at preferred 0.01-10 weight portion, particularly preferably in the 0.5-1 weight portion scope.

And, can introduce ultraviolet absorber such as benzotriazole, benzophenone, triazine or benzoic ether as required.

This optical compensating layer of the present invention can be introduced for example layer of surfactant, polymer dielectric, conduction complex compound, inorganic filler, pigment, dyestuff, antistatic agent, anti blocking agent and lubricant of other polymkeric substance and other composition in the situation that does not deviate from spirit of the present invention.

Next explanation comprises the coating layer (A) that comprises maleimide resin and the optical compensation films of stretch film layers (B).

Coating layer (A) as the composition of this optical compensation films is the coating layer that comprises maleimide resin.The example of maleimide resin comprises the polymer maleimides resin of N-replacement and the maleimide that N-replaces-copolymer-maleic anhydride resin.The example of the maleimide residue unit that the N-of formation maleimide resin replaces comprises the residue unit by the maleimide of the N-replacement of the above general formula that provides (1) expression.

Particularly preferably be N-normal-butyl polymer maleimides resin, N-hexyl polymer maleimides resin, N-octyl group polymer maleimides resin and N-octyl group maleimide-copolymer-maleic anhydride resin in these.Therefore these resins have excellent stratification character and are being given in optical compensation function and the optical compensation films of thermotolerance aspect excellence aspect the formation of layer.

The maleimide resin that consists of coating layer (A) can comprise and is different from maleimide residue unit that N-replaces and the residue unit of maleic anhydride residue unit, as long as this does not deviate from purpose of the present invention.The example of this optional residue unit comprises following one or more: distyryl compound residue unit such as styrene residue unit and α-methyl styrene residue unit; Acrylic acid residue unit; Acrylate residue unit such as methyl acrylate residue unit, ethyl acrylate residue unit and butyl acrylate residue unit; Methacrylic acid residue unit; Methacrylate residue unit such as methyl methacrylate residue unit, β-dimethyl-aminoethylmethacrylate residue unit and butyl methacrylate residue unit; Vinyl esters residue such as vinyl acetate residue, propionate residue, new vinyl acetate acid residue, vinyl laurate residue and stearic acid vinyl ester residue; The vinyl cyanide residue; Methacrylonitrile residue etc.

Preferably, maleimide resin for the number-average molecular weight (Mn) calculated take polystyrene standard by the elution curve that obtains in the gel permeation chromatography (hereinafter being called GPC) as 1 * 10 ³Or higher resin.Its number-average molecular weight is particularly preferably 2 * 10 ⁴To 2 * 10 ⁵, because this maleimide resin provides the coating layer (A) that has excellent mechanical properties and have excellent formability in the formation of layer.

In order to make the maleimide resin that consists of coating layer (A), can use any means, as long as obtain this maleimide resin.For example, this resin can be manufactured by the following: but maleimide and maleic anhydride that at least a N-is replaced randomly carry out free radical polymerization or free-radical polymerized with one or more monomers with the maleimide copolymerization of N-replacement.The example of the maleimide that N-replaces comprises following one or more: N-methyl maleimide, NEM, N-chloroethyl maleimide, N-methoxyethyl maleimide, N-n-pro-pyl maleimide, N-isopropyl maleimide, N-normal-butyl maleimide, N-isobutyl maleimide, N-sec-butyl maleimide, N-tert-butyl group maleimide, N-hexyl maleimide, the N-N-cyclohexylmaleimide, N-octyl group maleimide, N-lauryl maleimide etc.The example of described copolymerisable monomer comprises following one or more: distyryl compound such as styrene and α-methyl styrene; Acrylic acid; Acrylate such as methyl acrylate, ethyl acrylate and butyl acrylate; Methacrylic acid; Methacrylate such as methyl methacrylate, β-dimethyl-aminoethylmethacrylate and butyl methacrylate; Vinyl esters such as vinyl acetate, propionate, new vinyl acetate acid, vinyl laurate and stearic acid vinyl ester; Vinyl cyanide; Methacrylonitrile etc.

The coating layer (A) that consists of optical compensation films of the present invention is the coating layer that comprises maleimide resin, and particularly excellent aspect optical compensation function.The film of being made by polymkeric substance therein is used as in the situation of optical compensation films, and the three-dimensional refractive index of this film is usually by for example biaxial stretch-formed adjusting of film.But biaxial stretch-formed step has for example problem of manufacturing step and quality control complicated.The inventor finds, and is opposite with above-mentioned situation, and the coating layer that comprises maleimide resin shows this coating layer of being in unstretched state and has idiosyncratic behavior than low-refraction at the thickness direction of film.

Preferably, this optical compensation films of the present invention is that wherein coating layer (A) is the film of following coating layer, wherein ought in the plane of coating layer, be called respectively x1 axle and y1 axle by orthogonal two arbitrary axis, and when direction outside the plane (thickness direction) is called the z1 axle, coating layer capable of meeting requirements on three-dimensional index of refraction relationship nx1 ≈ ny1＞nz1 so, wherein nx1 is the refractive index on the x1 direction of principal axis, ny1 is that refractive index on the y1 direction of principal axis is (when nx1 is not equal to ny1, minimum refractive index is as nx1), and nz1 is the refractive index on the z1 direction of principal axis.Therefore this optical compensation films is particularly excellent aspect optical compensation function.

The thickness direction retardation (Rth1) of coating layer (A) can by change comprise maleimide coating layer thickness and easily regulate.With the light measurement of the measurement wavelength with 589nm and by its plane external delays (Rth1) of following formula (3) expression preferably in the 30-2000nm scope, because this coating layer (A) is so that optical compensation films can estimate to be suitable for use as phase shift films.Especially, its delay (Rth1) is at preferred 50-1000nm, more preferably in the scope of 80-500nm, because this coating layer (A) has the excellent effect of the viewing angle characteristic that improves liquid crystal display cells.

Rth1＝((nx1+ny1)/2-nz1)×d1 (3)

(in expression formula (3), d1 represents the thickness (nm) of coating layer (A)).

Preferably, the wavelength dependence little layer of coating layer (A) for postponing because in liquid crystal display cells use comprise this coating layer optical compensation films so that liquid crystal display cells can reduce at gamut.Especially, the wavelength dependence of its delay is preferably 1.1 or less, particularly 1.08 or less, the wavelength dependence of this delay (R450/R589) by the delay (R450) of the coating layer that tilts 40 degree and detect with the light of the measurement wavelength with 450nm with tilt 40 degree and represent with the ratio of the delay (R589) of the coating layer of the light detection of the measurement wavelength with 589nm.

Preferably, the transmittance of measuring according to JIS K 7361-1 (version in 1997) of coating layer (A) is 85% or higher, particularly 90% or higher, because resulting optical compensation films is given gratifying picture quality when for liquid crystal display cells.Also preferred, the mist degree of the coating layer (A) of measuring according to JIS K 7136 (version in 2000) is 2% or lower, particularly 1% or lower.

From the viewpoint of needed quality stability when the optical wavelength film that obtains is used for liquid crystal display cells, coating layer (A) preferably has high thermotolerance.Its glass transition temperature is preferably 100 ℃ or higher, and particularly preferably 120 ℃ or higher, even more preferably 135 ℃ or higher.

Stretch film layers (B) as the composition of this optical compensation films of the present invention comprises the stretching hyaline membrane.The example comprises the film of being made by polycarbonate resin, polyethersulfone resin, cyclic polyolefin resin and celluosic resin.The monadic stretching membrane of preferably being made by polycarbonate in these, the monadic stretching membrane of being made by polyethersulfone, the monadic stretching membrane of being made by cyclic polyolefin and the monadic stretching membrane of being made by celluosic resin, these films have positive birefringence separately.Particularly preferably, the stretch film layers of layer (B) for being made by cyclic polyolefin resin is because this layer is so that the wavelength dependence of the delay of optical compensation films is little.The positive birefringence of the term here refers to following character: the draw direction in the stretched film plane is called the x2 axle, direction is called the y2 axle in the plane vertical with this draw direction, and when (thickness) direction is called the z2 axle outside the plane of this film, this film capable of meeting requirements on three-dimensional index of refraction relationship nx2＞ny2 〉=nz2 so, wherein nx2 is the refractive index on the x2 direction of principal axis, ny2 is the refractive index on the y2 direction of principal axis, and nz2 is the refractive index on the z2 direction of principal axis.

Stretch film layers (B) be preferably wherein with the light measurement of the measurement wavelength with 589nm by postpone in the plane of following formula (4) expression (Re) in the 20-1000nm scope layer because resulting optical compensation films can estimate to be suitable for use as phase shift films.Especially, its delay (Re) is at preferred 50-500nm, more preferably in the scope of 80-300nm, because use the optical compensation films of this layer (B) to have the excellent effect of the viewing angle characteristic that improves liquid crystal display cells.In this, stretch film layers (B) can be made of two or more stretched film.For example, two films are used in respectively in the situation on the both sides of liquid crystal cells therein, postpone (Re) can be the delay shown in above half in the plane of each film.

Re＝(nx2-ny2)×d2 (4)

(in expression formula (4), d2 represents the thickness (nm) of stretch film layers (B)).

The stretched film that consists of stretch film layers (B) can be manufactured by the following: stretch by the film of solution casting method or melt extrusion method manufacturing with known stretcher.The commodity of stretched film also are available.

This optical compensation films of the present invention comprises coating layer (A) and stretch film layers (B), and is suitable for use as the optical compensation films of liquid crystal display cells.Especially, the transmittance of measuring according to JIS K 7361-1 (version in 1997) of preferred optical compensation films is 85% or higher, particularly 90% or higher, because this optical compensation films is given gratifying picture quality when for liquid crystal display cells.Also preferred, the mist degree of the optical compensation films of measuring according to JIS K7136 (version in 2000) is 2% or lower, particularly 1% or lower.

And, this optical compensation films of the present invention is preferably the direction of wherein working as slow axis in the plane of optical compensation films and is called the x3 axle, direction is called the y3 axle in the plane vertical with the x3 axle, when being called the z3 axle with (thickness) direction outside the plane of film and detecting this film with the light of the measurement wavelength with 589nm, this film has preferred 1.1 or larger so, particularly preferably 1.3 or larger, more preferably 2.0 or larger orientation parameter (Nz), wherein this orientation parameter is represented by following formula (5), wherein nx3 is the mean refractive index on the x3 direction of principal axis, ny3 is the mean refractive index on the y3 direction of principal axis, and nz3 is the mean refractive index on the z3 direction of principal axis.The term slow axis refers to the wherein the highest direction of principal axis of refractive index.

Nz＝(nx3-nz3)/(nx3-ny3) (5)

Be preferably 20-1000nm, particularly preferably 50-500nm by postponing (Re2) in its plane of following formula (8) expression.

Re2＝(nx3-ny3)×d5 (8)

(in expression formula (8), d5 represents the thickness (nm) of film).

Example for the manufacture of the method for optimizing of the optical compensation films that comprises the coating layer (A) that comprises maleimide resin and stretch film layers (B) of the present invention comprises: 1) wherein will be by maleimide resin solution being coated in the method that the coating layer of making in glass substrate or the film substrate is laminated to stretched film; 2) will be configured in comprising the coating layer of maleimide resin on the side of liquid crystal cell and stretched film will be configured in method on the opposite side; With 3) wherein maleimide resin solution is coated on the stretched film and dry method with the manufacturing coating layer.Preferably wherein maleimide resin solution is coated in these on stretched film and dry to make coating layer and to obtain thus the method for optical compensation films.Therefore optical compensation films of the present invention can more easily be made by the method.

Comprise wherein and will be coated on glass substrate, film substrate or the stretched film and the method by desolventizings such as heating afterwards by maleimide resin being dissolved in the solution for preparing in the solvent for the manufacture of the example of the method for coating layer (A).As the technology that be used for to apply, use such as scraping the skill in using a kitchen knife in cookery, rod and be coated with method, intaglio plate rubbing method, line of rabbet joint mould rubbing method, lip die head rubbing method, rubbing method etc. intermittently.Industrial, the intaglio plate rubbing method and intermittently rubbing method be generally used for respectively thin coating and thick coating.Employed solvent is especially restriction not.The example comprises arsol such as toluene, dimethylbenzene, chlorobenzene and nitrobenzene; Ketone solvent such as acetone, MEK, methyl isobutyl ketone and cyclohexanone; Ether solvents such as dimethyl ether, diethyl ether, methyl tert-butyl ether, tetrahydrofuran He diox; Acetic acid esters solvent such as methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate and butyl acetate; Hydrocarbon solvent such as hexane, cyclohexane, octane and decane; Alcoholic solvent such as methyl alcohol, ethanol, propyl alcohol and butanols; Chlorine compound solvent such as phenixin, chloroform, methylene chloride, ethylene dichloride and trichloroethanes; Amide solvent such as dimethyl formamide and dimethyl acetamide; And 1-METHYLPYRROLIDONE.Can use two or more combination of these solvents.In solution applies, preferably the solution viscosity with maleimide resin solution is adjusted to 10-10000cp, 10-5000cp particularly, because the coating of this solution can realize thickness accuracy and the excellent surface smoothness of high transparent, excellence, and make it possible to make the optical compensation films of excellent quality.

The thickness of the maleimide resin that applies is determined by the thickness direction retardation of coating layer (A).Especially, from obtaining having excellent surface smoothness and have the viewpoint of the excellent effect of improving viewing angle characteristic, dried thickness is at preferred 1-100 μ m, and more preferably 3-50 μ m is particularly preferably in the scope of 5-30 μ m.

Optical compensation films of the present invention can also comprise that the stratiform product of polaroid uses.

Antioxidant can be introduced in this optical compensation films of the present invention to strengthen thermal stability.The example of antioxidant comprises hindered phenol antioxidant, phosphorus compound antioxidant and other antioxidant.These antioxidants can be used alone or in combination.Preferably hindered phenol antioxidant and phosphorus compound antioxidant combination are used, because these antioxidants are realized the function of the anti-oxidation improved synergistically.In this case, particularly preferably 100-500 weight portion phosphorus compound antioxidant is mixed with 100 weight portion hindered phenol antioxidant.For the amount of antioxidant to be added, for the maleimide resin of per 100 weight portions formation this optical compensation films of the present invention, this amount is at preferred 0.01-10 weight portion, particularly preferably in the 0.5-1 weight portion scope.

This optical compensation films of the present invention can be introduced for example film of surfactant, polymer dielectric, conduction complex compound, inorganic filler, pigment, dyestuff, antioxidant, anti blocking agent and lubricant of other polymkeric substance and other composition in the situation that does not deviate from spirit of the present invention.

Below optical compensating layer is provided explanation, it is characterized in that: it is for to comprise the optical compensating layer that the coating layer of maleimide resin obtains by uniaxial tension, be called the x4 axle with the draw direction when this coating layer, the direction vertical with this draw direction is called the y4 axle, and when direction is called the z4 axle outside the plane, this optical compensating layer capable of meeting requirements on three-dimensional index of refraction relationship nx4＞ny4＞nz4 so, wherein nx4 is the refractive index on the x4 direction of principal axis, ny4 is the refractive index on the y4 direction of principal axis, and nz4 is the refractive index on the z4 direction of principal axis.

This optical compensation films of the present invention is to be characterised in that by uniaxial tension to comprise the optical compensation films that the coating layer of maleimide resin obtains.The example of maleimide resin comprises the polymer maleimides resin of N-replacement and the maleimide that N-replaces-copolymer-maleic anhydride resin.

The maleimide residue unit that the N-of the polymer maleimides resin that formation N-replaces replaces comprises the residue unit by the maleimide of the N-replacement of the above formula that provides (1) expression.

R1 in the residue unit of the maleimide that the N-by formula (1) expression replaces is straight chained alkyl, branched alkyl or naphthenic base, halogen group, ether, ester group or the amide group with 1-18 carbon atom.Example with straight chained alkyl of 1-18 carbon atom comprises methyl, ethyl, n-pro-pyl, normal-butyl, n-hexyl, n-octyl and positive lauryl.Example with branched alkyl of 1-18 carbon atom comprises isopropyl, isobutyl, sec-butyl and the tert-butyl group.Example with naphthenic base of 1-18 carbon atom comprises cyclohexyl.The example of halogen group comprises chlorine, bromine and iodine.

The instantiation of the maleimide residue unit that is replaced by the N-of formula (1) expression comprises and is selected from following one or more: N-methyl maleimide residue unit, NEM residue unit, N-chloroethyl maleimide residue unit, N-methoxyethyl maleimide residue unit, N-n-pro-pyl maleimide residue unit, N-normal-butyl maleimide residue unit, N-n-hexyl maleimide residue unit, N-n-octyl maleimide residue unit, the positive lauryl maleimide of N-residue unit, N-isopropyl maleimide residue unit, N-isobutyl maleimide residue unit, N-sec-butyl maleimide residue unit, N-tert-butyl group maleimide residue unit and N-N-cyclohexylmaleimide residue unit.Particularly preferably be NEM residue unit, N-normal-butyl maleimide residue unit, N-isobutyl maleimide residue unit, N-sec-butyl maleimide residue unit, N-tert-butyl group maleimide residue unit, N-n-hexyl maleimide residue unit and N-n-octyl maleimide residue unit.Therefore these unit provide the optical compensating layer that is easy to demonstrate delay and the dissolubility in solvent and physical strength excellence.

The instantiation of the polymer maleimides resin that N-replaces comprises following one or more: N-methyl polymer maleimides resin, the NEM fluoropolymer resin, N-chloroethyl polymer maleimides resin, N-methoxyethyl polymer maleimides resin, N-n-pro-pyl polymer maleimides resin, N-normal-butyl polymer maleimides resin, N-n-hexyl polymer maleimides resin, N-n-octyl polymer maleimides resin, the positive lauryl polymer maleimides of N-resin, N-isopropyl polymer maleimides resin, N-isobutyl polymer maleimides resin, N-sec-butyl polymer maleimides resin, N-tert-butyl group polymer maleimides resin and N-N-cyclohexylmaleimide fluoropolymer resin.Particularly preferably be NEM fluoropolymer resin, N-normal-butyl polymer maleimides resin, N-isobutyl polymer maleimides resin, N-sec-butyl polymer maleimides resin, N-tert-butyl group polymer maleimides resin, N-n-hexyl polymer maleimides resin, N-n-octyl polymer maleimides resin etc.Therefore these resins provide the optical compensating layer that is easy to demonstrate delay and the dissolubility in solvent and physical strength excellence.

And the example of the maleimide that N-replaces-copolymer-maleic anhydride resin comprises N-methyl maleimide-copolymer-maleic anhydride resin, NEM-copolymer-maleic anhydride resin, N-chloroethyl maleimide-copolymer-maleic anhydride resin, N-methoxyethyl maleimide-copolymer-maleic anhydride resin, N-n-pro-pyl maleimide-copolymer-maleic anhydride resin, N-normal-butyl maleimide-copolymer-maleic anhydride resin, N-n-hexyl maleimide-copolymer-maleic anhydride resin, N-n-octyl maleimide-copolymer-maleic anhydride resin, the positive lauryl maleimide of N--copolymer-maleic anhydride resin, N-isopropyl maleimide-copolymer-maleic anhydride resin, N-isobutyl maleimide-copolymer-maleic anhydride resin, N-sec-butyl maleimide-copolymer-maleic anhydride resin, N-tert-butyl group maleimide-copolymer-maleic anhydride resin and N-N-cyclohexylmaleimide-copolymer-maleic anhydride resin.

Particularly preferably, maleimide resin is the positive ethyl maleimide fluoropolymer resin of N-, N-normal-butyl polymer maleimides resin, N-n-hexyl polymer maleimides resin, N-n-octyl polymer maleimides resin or the N-n-octyl maleimide-copolymer-maleic anhydride resin in these resins.Therefore these resins have excellent stratification character and are being given in optical compensation function and the optical compensation films of thermotolerance aspect excellence aspect the formation of layer.

Preferably, maleimide resin for the number-average molecular weight (Mn) calculated take polystyrene standard by the elution curve that obtains in the gel permeation chromatography (hereinafter being called GPC) as 1 * 10 ³Or higher resin.Its number-average molecular weight is particularly preferably 2 * 10 ⁴To 2 * 10 ⁵, because this maleimide resin provides the optical compensating layer that has excellent engineering properties and have excellent formability in the formation of layer.

In order to make the maleimide resin that consists of this optical compensating layer of the present invention, can use any means, as long as obtain this maleimide resin.For example, this resin can be manufactured by the following: but maleimide and maleic anhydride that at least a N-is replaced randomly carry out free radical polymerization or free-radical polymerized with one or more monomers with the maleimide copolymerization of N-replacement.The example of the maleimide that N-replaces comprises following one or more: N-methyl maleimide, NEM, N-chloroethyl maleimide, N-methoxyethyl maleimide, N-n-pro-pyl maleimide, N-normal-butyl maleimide, N-n-hexyl maleimide, N-n-octyl maleimide, the positive lauryl maleimide of N-, N-isopropyl maleimide, N-isobutyl maleimide, N-sec-butyl maleimide, N-tert-butyl group maleimide, N-N-cyclohexylmaleimide etc.The example of described copolymerisable monomer comprises following one or more: distyryl compound such as styrene and α-methyl styrene; Acrylic acid; Acrylate such as methyl acrylate, ethyl acrylate and butyl acrylate; Methacrylic acid; Methacrylate such as methyl methacrylate, β-dimethyl-aminoethylmethacrylate and butyl methacrylate; Vinyl esters such as vinyl acetate, propionate, new vinyl acetate acid, vinyl laurate and stearic acid vinyl ester; Vinyl cyanide; Methacrylonitrile etc.

Be no particular limitation in solvent available in solution polymerization, suspension polymerization, precipitation polymerization and the emulsion polymerization.The example comprises arsol such as benzene, toluene and dimethylbenzene; Alcoholic solvent such as methyl alcohol, ethanol, propyl alcohol and butanols; Cyclohexane; Diox; Tetrahydrofuran (THF); Acetone; MEK; Dimethyl formamide; Isopropyl acetate; Water; 1-METHYLPYRROLIDONE; And dimethyl formamide.The example also comprises two or more mixed solvents that consist of by these.

This optical compensating layer of the present invention is to comprise the film that the coating layer of maleimide resin obtains by uniaxial tension.This optical compensating layer is optical compensation function excellence as optical compensating layer the time particularly.Usually, biaxial stretch-formed is very difficult to regulate three-dimensional refractive index.Because the screen area of display increases and the therefore area change of optical compensating layer, regulates equably the entire area difficult, causes productive rate reduction etc.In the present invention, by the specific coating layer of uniaxial tension, can obtain having the optical compensating layer of excellent optical compensation function.This optical compensating layer of the present invention is characterised in that: it is to comprise the optical compensating layer that the coating layer of maleimide resin obtains by uniaxial tension, when the tensile axis direction of this coating layer is called the x4 axle, the direction vertical with this draw direction is called the y4 axle, and when direction is called the z4 axle outside the plane, this optical compensating layer capable of meeting requirements on three-dimensional index of refraction relationship nx4＞ny4＞nz4 so, wherein nx4 is the refractive index on the x4 direction of principal axis, ny4 is the refractive index on the y4 direction of principal axis, and nz4 is the refractive index on the z4 direction of principal axis.

Postponing (Re1) in the plane of this optical compensating layer of the present invention can easily regulate by the thickness that changes the coating layer of being made by maleimide resin and the condition that changes uniaxial tension.With the light measurement of the measurement wavelength with 589nm and be preferred 20nm or larger by delay (Re1) in its plane of following formula (6) expression, 30nm-200nm especially, more preferably 40nm-150nm is because this optical compensating layer can estimate to be suitable for use as phase shift films.

Re1＝(nx4-ny4)×d3 (6)

(in expression formula (6), d3 represents the thickness (nm) of optical compensating layer).

And the plane external delays (Rth2) of this optical compensating layer of the present invention can easily be regulated by the thickness that changes the coating layer of being made by maleimide resin and the condition that changes uniaxial tension.With the light measurement of the measurement wavelength with 589nm and by its plane external delays (Rth2) of following formula (7) expression preferably in the 30-2000nm scope, because this optical compensating layer can estimate to be suitable for use as phase shift films.Especially, its delay (Rth2) is at preferred 50-1000nm, more preferably in the scope of 80-400nm, because this optical compensating layer has the excellent effect of the viewing angle characteristic that improves liquid crystal display cells.

Rth2＝((nx4+ny4)/2-nz4)×d4 (7)

(in expression formula (7), d4 represents the thickness (nm) of optical compensating layer).

Preferably, the wavelength dependence little layer of this optical compensating layer of the present invention for postponing is because use this optical compensating layer so that liquid crystal display cells can reduce at gamut in liquid crystal display cells.The wavelength dependence of its delay (R450/R589) is preferably 1.1 or less, particularly 1.08 or less, the wavelength dependence of this delay (R450/R589) is represented by the ratio of the delay (R450) of measuring with the measurement wavelength of 450nm with the delay (R589) of measuring with the measurement wavelength of 589nm.

The thickness of this optical compensating layer of the present invention is preferred 1-100 μ m, more preferably 3-50 μ m, and 5-30 μ m particularly preferably is because have the excellent effect that the optical compensating layer of this thickness has excellent surface smoothness and improves viewing angle characteristic.

Preferably, the transmittance of this optical compensating layer of the present invention is 85% or higher, particularly 90% or higher, because this optical compensating layer is given gratifying picture quality when being used for liquid crystal display cells.Also preferred, the mist degree of this optical compensating layer is 2% or lower, particularly 1% or lower.

From the viewpoint of the quality stability liquid crystal display cells, this optical compensating layer of the present invention preferably has high thermotolerance.Its glass transition temperature is preferably 100 ℃ or higher, and particularly preferably 120 ℃ or higher, even more preferably 135 ℃ or higher.

This optical compensating layer of the present invention is characterised in that by uniaxial tension and comprises that the coating layer of maleimide resin obtains.Comprise wherein that for the manufacture of the example of the method for optimizing of this layer the maleimide resin with solution state is coated in the film substrate of being made by for example celluosic resin or poly-(ethylene glycol terephthalate) resin (PET) and the method for the coat substrates of drying and uniaxial tension gained.For coating, can use wherein and will be coated on the film and subsequently by the desolventizings such as the heating method of the coating layer of uniaxial tension gained then by maleimide resin being dissolved in the solution for preparing in the solvent.As the technology that be used for to apply, use such as scraping the skill in using a kitchen knife in cookery, rod and be coated with method, intaglio plate rubbing method, line of rabbet joint mould rubbing method, lip die head rubbing method, rubbing method etc. intermittently.Industrial, the intaglio plate rubbing method and intermittently rubbing method be generally used for respectively thin coating and thick coating.

Employed solvent is especially restriction not.The example comprises arsol such as toluene, dimethylbenzene, chlorobenzene and nitrobenzene; Ketone solvent such as acetone, MEK, methyl isobutyl ketone and cyclohexanone; Ether solvents such as dimethyl ether, diethyl ether, methyl tert-butyl ether, tetrahydrofuran He diox; Acetic acid esters solvent such as methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate and butyl acetate; Hydrocarbon solvent such as hexane, cyclohexane, octane and decane; Alcoholic solvent such as methyl alcohol, ethanol, propyl alcohol and butanols; Chlorine compound solvent such as phenixin, chloroform, methylene chloride, ethylene dichloride and trichloroethanes; Amide solvent such as dimethyl formamide and dimethyl acetamide; And 1-METHYLPYRROLIDONE.Can use two or more combination of these solvents.In solution applied, the viscosity of coating solution was the very important factor that forms the coating with high transparent and thickness accuracy and surface smoothness excellence.The viscosity of this coating solution is preferred 10-10000cp, particularly preferably 10-5000cp.

The thickness of the maleimide resin that will apply in this operation is determined by the thickness direction retardation of coating layer.Especially, from obtaining having excellent surface smoothness and improve the viewpoint of optical compensating layer of the excellent effect of viewing angle characteristic, its dried thickness is at preferred 1-100 μ m, and more preferably 3-50 μ m is particularly preferably in the scope of 5-30 μ m.

Be used for obtaining the not especially restriction of uniaxial tension of this optical compensation films of the present invention.Usually, coating layer can stretch by the draw ratio with 1.1-5 under than the condition of the draft temperature of high-30 to 50 ℃ of the glass transition temperature of the coating layer of measuring with differential scanning calorimeter.Thickness offset is minimized, because optical property, for example particularly delay, transmittance and mist degree are subject to the thickness considerable influence.In coating layer of the present invention stretched, draft temperature can reduce to allow that partial solvent is residual by the drying condition of regulating in the coating layer manufacturing.Coating layer can peeled off after stretching from basilar memebrane, or can stretch with basilar memebrane.

The example that can be used for the method for uniaxial tension of the present invention comprises for example following method: wherein with the method for stenter stretching coating layer, wherein by with the method for calender roll extrusion and stretching coating layer and the method for stretching coating layer between roller wherein.

This optical compensating layer of the present invention can use after peeling off from basilar memebrane, can comprise that maybe the form of the stratiform product of basilar memebrane or other blooming is used.Especially, in the situation that optical compensating layer uses with the stratiform product that comprises other blooming, from the viewpoint of the transparency and intensity, described other blooming is preferably cellulose membrane or cyclic polyolefin film.

This optical compensating layer of the present invention can also comprise that the stratiform product of polaroid uses.

Antioxidant can be introduced in this optical compensating layer of the present invention to strengthen thermal stability.The example of antioxidant comprises hindered phenol antioxidant, phosphorus compound antioxidant and other antioxidant.These antioxidants can be used alone or in combination.Preferably hindered phenol antioxidant and phosphorus compound antioxidant combination are used, because these antioxidants are realized the function of the anti-oxidation improved synergistically.In this case, particularly preferably 100-500 weight portion phosphorus compound antioxidant is mixed with 100 weight portion hindered phenol antioxidant.For the amount of antioxidant to be added, consist of the maleimide resin of optical compensating layer of the present invention for per 100 weight portions, this amount is at preferred 0.01-10 weight portion, particularly preferably in the 0.5-1 weight portion scope.

Embodiment

The below illustrates in greater detail the present invention with reference to embodiment.But, in any case the present invention should not be construed as the restriction that is subjected to following examples.

The mensuration of number-average molecular weight:

Use gel permeation chromatograph (GPC) (trade name, HLC-802A; Made by Tosoh Corp.), and dimethyl formamide is as solvent.The pH-value determination pH of number-average molecular weight so that polystyrene standard is calculated.

The measurement of glass transition temperature:

Differential scanning calorimeter (trade name, DSC2000; By Seiko Instruments﹠amp; ElectronicsLtd. make) be used for measuring with 10 ℃/minute the rate of heat addition.

The mensuration of transmittance:

Transmittance is according to the measure mensuration of JIS K 7361-1 (version in 1997) as the transparency.

The mensuration of mist degree:

Mist degree is according to the measure mensuration of JIS K 7136 (version in 2000) as the transparency.

The calculating of three-dimensional refractive index:

Sample inclination type automatic birefringence instrument (trade name, KOBRA-WR; Made by Oji ScientificInstruments) be used for when changing the elevation angle photo measure three-dimensional refractive index with the measurement wavelength with 589nm.And, from three-dimensional refractive index Calculation Plane external delays (Rth, Rth1 or Rth2).

Wavelength dependence (R450/R589) with the ratio display delay of the delay (R589) under the delay (R450) of measuring under the measurement wavelength of 450nm and measurement wavelength at 589nm, measured.

Synthetic example 1 (the manufacturing embodiment of N-normal-butyl polymer maleimides resin)

Introduce 32.4g N-normal-butyl maleimide and 0.054g in the sealed glass tube as 2 of polymerization initiator, 2 '-azo-bis-iso-dimethyl.Behind nitrogen replacement, under the condition of the polymerization time of 60 ℃ polymerization temperatures and 5 hours, carry out Raolical polymerizable.After reaction, add chloroform to obtain polymer solution.Afterwards, this solution is mixed to make thus polymer precipitation with excessive methanol.The polymkeric substance that obtains is taken out by filtering, fully wash with methyl alcohol subsequently, and lower dry at 80 ℃.Thus, measure N-normal-butyl polymer maleimides resin with 20g.The N-normal-butyl polymer maleimides resin that obtains has 120,000 number-average molecular weight.

Synthetic example 2 (the manufacturing embodiment of N-n-hexyl polymer maleimides resin)

Introduce 40g N-n-hexyl maleimide and 0.05g in the sealed glass tube as 2 of polymerization initiator, 2 '-azo-bis-iso-dimethyl.Behind nitrogen replacement, under the condition of the polymerization time of 60 ℃ polymerization temperatures and 5 hours, carry out Raolical polymerizable.After reaction, add chloroform to obtain polymer solution.Afterwards, this solution is mixed to make thus polymer precipitation with excessive methanol.The polymkeric substance that obtains is taken out by filtering, fully wash with methyl alcohol subsequently, and lower dry at 80 ℃.Thus, measure N-n-hexyl polymer maleimides resin with 32g.The N-n-hexyl polymer maleimides resin that obtains has 160,000 number-average molecular weight.

Synthetic example 3 (the manufacturing embodiment of N-n-octyl polymer maleimides resin)

Introduce 28g N-n-octyl maleimide and 0.032g in the sealed glass tube as 2 of polymerization initiator, 2 '-azo-bis-iso-dimethyl.Behind nitrogen replacement, under the condition of the polymerization time of 60 ℃ polymerization temperatures and 5 hours, carry out Raolical polymerizable.After reaction, add chloroform to obtain polymer solution.Afterwards, this solution is mixed to make thus polymer precipitation with excessive methanol.The polymkeric substance that obtains is taken out by filtering, fully wash with methyl alcohol subsequently, and lower dry at 80 ℃.Thus, measure N-n-octyl polymer maleimides resin with 15g.The N-n-octyl polymer maleimides resin that obtains has 270,000 number-average molecular weight.

Synthetic example 4 (the manufacturing embodiment 1 of N-n-octyl maleimide-copolymer-maleic anhydride resin)

In sealed glass tube, introduce 26g N-n-octyl maleimide, 2.4g maleic anhydride and 0.036g as 2 of polymerization initiator, 2 '-azo-bis-iso-dimethyl.Behind nitrogen replacement, under the condition of the polymerization time of 60 ℃ polymerization temperatures and 5 hours, carry out Raolical polymerizable.After reaction, add chloroform to obtain polymer solution.Afterwards, this solution is mixed to make thus polymer precipitation with excessive methanol.The polymkeric substance that obtains is taken out by filtering, fully wash with methyl alcohol subsequently, and lower dry at 80 ℃.Thus, measure N-n-octyl maleimide-copolymer-maleic anhydride resin with 19g.The N-n-octyl maleimide that obtains-copolymer-maleic anhydride resin comprise 20 % by weight amount the maleic anhydride residue and have 120,000 number-average molecular weight.

Synthetic example 5 (the manufacturing embodiment 2 of N-n-octyl maleimide-copolymer-maleic anhydride resin)

In sealed glass tube, introduce 26g N-n-octyl maleimide, 4.8g maleic anhydride and 0.04g as 2 of polymerization initiator, 2 '-azo-bis-iso-dimethyl.Behind nitrogen replacement, under the condition of the polymerization time of 60 ℃ polymerization temperatures and 5 hours, carry out Raolical polymerizable.After reaction, add chloroform to obtain polymer solution.Afterwards, this solution is mixed to make thus polymer precipitation with excessive methanol.The polymkeric substance that obtains is taken out by filtering, fully wash with methyl alcohol subsequently, and lower dry at 80 ℃.Thus, measure N-n-octyl maleimide-copolymer-maleic anhydride resin with 18g.The N-n-octyl maleimide that obtains-copolymer-maleic anhydride resin comprise 40 % by weight amount maleic anhydride residue unit and have 140,000 number-average molecular weight.

Synthetic example 6 (the manufacturing embodiment 3 of N-n-octyl maleimide-copolymer-maleic anhydride resin)

In sealed glass tube, introduce 26g N-n-octyl maleimide, 4.8g maleic anhydride and 0.04g as 2 of polymerization initiator, 2 '-azo-bis-iso-dimethyl.Behind nitrogen replacement, under the condition of the polymerization time of 60 ℃ polymerization temperatures and 5 hours, carry out Raolical polymerizable.After reaction, add chloroform to obtain polymer solution.Afterwards, this solution is mixed to make thus polymer precipitation with excessive methanol.The polymkeric substance that obtains is taken out by filtering, fully wash with methyl alcohol subsequently, and lower dry at 80 ℃.Thus, measure N-n-octyl maleimide-copolymer-maleic anhydride resin with 18g.The N-n-octyl maleimide that obtains-copolymer-maleic anhydride resin comprise 20 % by weight amount maleic anhydride residue unit and have 140,000 number-average molecular weight.

Synthetic example 7 (the manufacturing embodiment of the positive ethyl maleimide fluoropolymer resin of N-)

Introduce the positive ethyl maleimide of 45g N-and 0.05g in the sealed glass tube as 2 of polymerization initiator, 2 '-azo-bis-iso-dimethyl.Behind nitrogen replacement, under the condition of the polymerization time of 60 ℃ polymerization temperatures and 5 hours, carry out Raolical polymerizable.After reaction, add chloroform to obtain polymer solution.Afterwards, this solution is mixed to make thus polymer precipitation with excessive methanol.The polymkeric substance that obtains is taken out by filtering, fully wash with methyl alcohol subsequently, and lower dry at 80 ℃.Thus, measure the positive ethyl maleimide fluoropolymer resin of N-with 20g.The positive ethyl maleimide fluoropolymer resin of the N-that obtains has 80,000 number-average molecular weight.

Synthetic example 8 (the manufacturing embodiment 4 of N-n-octyl maleimide-copolymer-maleic anhydride resin)

In sealed glass tube, introduce 26g N-n-octyl maleimide, 2.4g maleic anhydride and 0.036g as 2 of polymerization initiator, 2 '-azo-bis-iso-dimethyl.Behind nitrogen replacement, under the condition of the polymerization time of 60 ℃ polymerization temperatures and 5 hours, carry out Raolical polymerizable.After reaction, add chloroform to obtain polymer solution.Afterwards, this solution is mixed to make thus polymer precipitation with excessive methanol.The polymkeric substance that obtains is taken out by filtering, fully wash with methyl alcohol subsequently, and lower dry at 80 ℃.Thus, measure N-n-octyl maleimide-copolymer-maleic anhydride resin with 19g.The N-n-octyl maleimide that obtains-copolymer-maleic anhydride resin comprise 20 % by weight amount the maleic anhydride residue and have 140,000 number-average molecular weight.

Make embodiment 1 (the manufacturing embodiment of the monadic stretching membrane of cyclic polyolefin resin)

With the cyclic polyolefin resin (polynorbornene with ester group of hydrogenation; Made by Aldrich Co.) be dissolved in the dichloromethane solution solution to obtain 25%.To 0.35 weight portion three (2 of its interpolation as antioxidant, the 4-di-tert-butyl-phenyl) (3-(3 for phosphite ester and 0.15 weight portion pentaerythrite four, the 5-di-tert-butyl-hydroxy phenyl) propionic ester) and as the 1 weight portion 2-(2H-benzotriazole-2-yl) of ultraviolet absorber-paracresol, based on per 100 weight portion cyclic polyolefin resins.Afterwards, with the gained potpourri by T-die head method curtain coating and lower dry to obtain the film of width 250mm and thickness 100 μ m 40 ℃, 80 ℃ and 120 ℃ on the carrier of solution casting device.It is the square of 50mm that the film that obtains is cut into the length of side.The unsupported width uniaxial tension that the film experience that makes cutting is carried out with biaxial stretch-formed device (by Imoto Machinery Co.Ltd. manufacturing) under the condition of the draw speed of 180 ℃ temperature and 15mm/ minute.Thus film is stretched+100%.

The stretched film of gained shows positive birefringence, and its three-dimensional refractive index is nx2=1.5124, ny2=1.5090 and nz2=1.5090.That is, nx2＞ny2=nz2.This stretched film has and postpones (Re) in the plane of 121nm.The wavelength dependence (R450/R550) that postpones in its plane is 1.01.

Embodiment 1

The N-normal-butyl polymer maleimides resin dissolves that will in synthetic example 1, obtain in chloroform to prepare 12% solution.With this solution by coating machine curtain coating on the glass substrate and at room temperature dry 24 hours to obtain the coating layer on glass substrate.Thus, make the coating tunic of width 50mm and thickness 20 μ m.Measure the glass transition temperature (Tg) of this coating tunic, the result is 179 ℃.

The coating layer that obtains has 91.6% transmittance and 0.6% mist degree, and its three-dimensional refractive index is nx=1.51607, ny=1.51607 and nz=1.50954.This layer has and postpones in the plane of 0nm and the Rth of 130.6nm.The value of its R450/R589 that shows the wavelength dependence of delay is 1.06, shows that this coating layer has the function of optical compensating layer.

Embodiment 2

The N-n-hexyl polymer maleimides resin dissolves that will in synthetic example 2, obtain in chloroform to prepare 15% solution.With this solution by coating machine curtain coating on the glass substrate and at room temperature dry 24 hours to obtain the coating layer on glass substrate.Thus, make the coating tunic of width 50mm and thickness 30 μ m.Measure the Tg of this coating tunic, the result is 149 ℃.

The coating layer that obtains has 91.8% transmittance and 0.7% mist degree, and its three-dimensional refractive index is nx=1.52000, ny=1.52002 and nz=1.51638.This layer has and postpones in the plane of 0.6nm and the Rth of 108.9nm.The value of its R450/R589 that shows the wavelength dependence of delay is 1.05, shows that this coating layer has the function of optical compensating layer.

Embodiment 3

The N-n-octyl polymer maleimides resin dissolves that will in synthetic example 3, obtain in chloroform to prepare 16% solution.With this solution by coating machine curtain coating on the glass substrate and at room temperature dry 24 hours to obtain the coating layer on glass substrate.Thus, make the coating tunic of width 50mm and thickness 50 μ m.Measure the Tg of this coating tunic, the result is 145 ℃.

The coating layer that obtains has 92.78% transmittance and 0.9% mist degree, and its three-dimensional refractive index is nx=1.51049, ny=1.51049 and nz=1.50833.This layer has and postpones in the plane of 0nm and the Rth of 108nm.The value of its R450/R589 that shows the wavelength dependence of delay is 1.05, shows that this coating layer has the function of optical compensating layer.

Embodiment 4

The N-n-octyl maleimide that will in synthetic example 4, obtain-copolymer-maleic anhydride resin dissolves in chloroform to prepare 16% solution.With this solution by coating machine curtain coating on the glass substrate and at room temperature dry 24 hours to obtain the coating layer on glass substrate.Thus, make the coating tunic of width 50mm and thickness 50 μ m.Measure the Tg of this coating tunic, the result is 150 ℃.

The coating layer that obtains has 92.2% transmittance and 0.8% mist degree, and its three-dimensional refractive index is nx=1.50680, ny=1.50680 and nz=1.50422.This layer has and postpones in the plane of 0nm and the Rth of 129nm.The value of its R450/R589 that shows the wavelength dependence of delay is 1.05, shows that this coating layer has the function of optical compensating layer.

Embodiment 5

The N-n-octyl maleimide that will in synthetic example 5, obtain-copolymer-maleic anhydride resin dissolves in chloroform to prepare 16% solution.With this solution by coating machine curtain coating on the glass substrate and at room temperature dry 24 hours to obtain the coating layer on glass substrate.Thus, make the coating tunic of width 50mm and thickness 50 μ m.Measure the Tg of this coating tunic, the result is 156 ℃.

The coating layer that obtains has 92.0% transmittance and 0.9% mist degree, and its three-dimensional refractive index is nx=1.51593, ny=1.51594 and nz=1.51193.This layer has and postpones in the plane of 0.3nm and the Rth of 200nm.The value of its R450/R589 that shows the wavelength dependence of delay is 1.05, shows that this coating layer has the function of optical compensating layer.

Embodiment 6

The N-normal-butyl polymer maleimides resin dissolves that will in synthetic example 1, obtain in chloroform to prepare 12% solution.With this solution by coating machine the upper curtain coating of the film of being made by triacetyl cellulose (hereinafter being called the TAC film) and at room temperature dry 24 hours to obtain the coating layer on the TAC film.This coating layer is peeled off from the TAC film.Thus, make the coating tunic of width 50mm and thickness 20 μ m.Measure the glass transition temperature (Tg) of this coating layer, the result is 179 ℃.

The coating layer that obtains has 91.5% transmittance and 0.6% mist degree, and its three-dimensional refractive index is nx=1.51606, ny=1.51606 and nz=1.50954.This layer has and postpones in the plane of 0nm and the Rth of 130.4nm.The value of its R450/R589 that shows the wavelength dependence of delay is 1.06, shows that this coating layer has the function of optical compensating layer.The character that obtains among these character and the embodiment 1 is almost equal.Not in the situation of TAC film release-coated layer, estimate the optical property of stratiform product.As a result, find that the stratiform product has the Rth of delay and 156.8nm in the plane of 90.2% transmittance, 0.8% mist degree, 0nm.The value of its R450/R589 that shows the wavelength dependence of delay is 1.05, shows that this stratiform product has the function of optical compensation films.

Embodiment 7

The coating layer that obtains has 91.6% transmittance and 0.6% mist degree, and its three-dimensional refractive index is nx1=1.51607, ny1=1.51607 and nz1=1.50954.This layer has and postpones in the plane of 0nm and the Rth1 of 130.6nm.The value of its R450/R589 that shows the wavelength dependence of delay is 1.06, shows that this coating layer has the function of optical compensating layer.

The coating layer that obtains is layered on the stretched film that obtains among the manufacturing embodiment 1 to make stacked film.

The stacked film that obtains has the orientation parameter (Nz) that postpones (Re2) and 2.14 in the plane of 90.2% transmittance, 0.8% mist degree, 121nm, shows that this stacked film has the function of optical compensation films.

Embodiment 8

The coating layer that obtains has 92.78% transmittance and 0.9% mist degree, and its three-dimensional refractive index is nx1=1.51049, ny1=1.51049 and nz1=1.50833.This layer has and postpones in the plane of 0nm and the Rth1 of 108nm.The value of its R450/R589 that shows the wavelength dependence of delay is 1.05, shows that this coating layer has the function of optical compensating layer.

The stacked film that obtains has the orientation parameter (Nz) that postpones (Re2) and 1.36 in the plane of 90.2% transmittance, 0.8% mist degree, 121nm, shows that this stacked film has the function of optical compensation films.

Embodiment 9

The N-n-octyl maleimide that will in synthetic example 6, obtain-copolymer-maleic anhydride resin dissolves in chloroform to prepare 16% solution.With this solution by coating machine curtain coating on the glass substrate and at room temperature dry 24 hours to obtain the coating layer on glass substrate.Thus, make the coating tunic of width 50mm and thickness 50 μ m.Measure the Tg of this coating tunic, the result is 156 ℃.

The coating layer that obtains has 92.0% transmittance and 0.7% mist degree, and its three-dimensional refractive index is nx1=1.51593, ny1=1.51593 and nz1=1.51193.This layer has and postpones in the plane of 0.3nm and the Rth1 of 200nm.The value of its R450/R589 that shows the wavelength dependence of delay is 1.05, shows that this coating layer has the function of optical compensating layer.

The stacked film that obtains has the orientation parameter (Nz) that postpones (Re2) and 2.53 in the plane of 904% transmittance, 0.9% mist degree, 121nm, shows that this stacked film has the function of optical compensation films.

Embodiment 10

The N-normal-butyl polymer maleimides resin dissolves that will in synthetic example 1, obtain in chloroform to prepare 12% solution.Curtain coating and at room temperature dry 24 hours are to obtain comprising the stretched film of cyclic polyolefin resin and the stacked film of coating layer on the stretched film that this solution is obtained in making embodiment 1.This coating layer is peeled off from the part of stacked film.Thus, make the coating layer of width 50mm and thickness 20 μ m.Measure the glass transition temperature (Tg) of this coating layer, the result is 179 ℃.

The coating layer that obtains has 91.5% transmittance and 0.6% mist degree, and its three-dimensional refractive index is nx1=1.51606, ny1=1.51606 and nz1=1.50954.This layer has and postpones in the plane of 0nm and the Rth1 of 130.4nm.The value of its R450/R589 that shows the wavelength dependence of delay is 1.06, shows that this coating layer has the function of optical compensating layer.The character that obtains among these character and the embodiment 1 is almost equal.And, the optical property of the stacked film that obtains according to the original state evaluation.As a result, find that stacked film has the orientation parameter (Nz) of delay (Re2) in the plane of 91.5% transmittance, 0.6% mist degree, 121nm and 2.14, shows that this stacked film has the function of optical compensation films.

Embodiment 11

The positive ethyl maleimide fluoropolymer resin of the N-that will obtain in synthetic example 7 is dissolved in the chloroform solution to prepare 12%.This solution is descended dry 15 minutes to obtain coating layer by coating machine in curtain coating on the PET film of organosilicon processing and at 90 ℃.Thus, make the coating layer of width 100mm and thickness 30 μ m.Measure the glass transition temperature (Tg) of this coating layer, the result is 255 ℃.

The coating layer that obtains peeled off and under 270 ℃ with 1.5 draw ratio uniaxial tension.The layer that obtains has thickness, 92% transmittance and 0.6% the mist degree of 30 μ m, and its three-dimensional refractive index is nx4=1.5252, ny4=1.5232 and nz4=1.5168.This layer has the plane external delays (Rth2) that postpones (Re1) and 222nm in the plane of 60nm.The value of its R450/R589 that shows the wavelength dependence of delay is 1.07, shows that this layer has the function of optical compensating layer.

Embodiment 12

The N-normal-butyl polymer maleimides resin dissolves that will in synthetic example 1, obtain in chloroform to prepare 12% solution.This solution is descended dry 15 minutes to obtain coating layer by coating machine in curtain coating on the PET film of organosilicon processing and at 90 ℃.Thus, make the coating layer of width 50mm and thickness 25 μ m.Measure the glass transition temperature (Tg) of this coating layer, the result is 179 ℃.

The coating layer that obtains peeled off and under 190 ℃ with 1.5 draw ratio uniaxial tension.The layer that obtains has thickness, 91.6% transmittance and 0.5% the mist degree of 20 μ m, and its three-dimensional refractive index is nx4=1.5182, ny4=1.5145 and nz4=1.5078.This layer has the plane external delays (Rth2) that postpones (Re1) and 171nm in the plane of 74nm.The value of its R450/R589 that shows the wavelength dependence of delay is 1.06, shows that this layer has the function of optical compensating layer.

Embodiment 13

The N-n-octyl maleimide that will in synthetic example 8, obtain-copolymer-maleic anhydride resin dissolves in tetrahydrofuran to prepare 15% solution.With this solution by coating machine on the cyclic polyolefin film curtain coating and 90 ℃ lower dry 10 minutes to obtain having the coating layer of 75 μ m thickness.This coating layer has 150 ℃ Tg.The coating layer that obtains is carried out uniaxial tension with cyclic polyolefin substrate draw ratio with 1.5 under 160 ℃.After stretching, optical property is peeled off and estimated to coating layer from basilar memebrane.

The layer that obtains has thickness, 92.2% transmittance and 0.5% the mist degree of 20 μ m, and its three-dimensional refractive index is nx4=1.5079, ny4=1.5056 and nz4=1.5033.This layer has the Rth2 that postpones (Re1) and 172.5nm in the plane of 115nm.The value of its R450/R589 that shows the wavelength dependence of delay is+1.04, shows that this layer has the function of optical compensating layer.

Comparative example 1

In 1 liter of autoclave, introduce 400mL as toluene, 0.001 mole of neodecanoic acid tert-butyl ester as polymerization initiator (perbutyl neodecanoate), 0.42 mole of N-(2,6-diethyl phenyl) maleimide and 4.05 moles of isobutylenes of polymer solvent.Polymerization time with 5 hours under 60 ℃ polymerization temperature carries out polyreaction to obtain N-(2,6-diethyl phenyl) maleimide-isobutylene alternating copolymer.The N-that obtains (2,6-diethyl phenyl) maleimide-isobutylene alternating copolymer has 65,000 number-average molecular weight.

Preparation is by the N-that obtains (2, the 6-diethyl phenyl) maleimide-isobutylene alternating copolymer of 20 % by weight and the solution of 80 % by weight methylene chloride formation.With this solution curtain coating on the PET film, and the methylene chloride that from solution, volatilizees.Peel off the cured film of N-(2, the 6-diethyl phenyl) maleimide-isobutylene alternating copolymer of gained.With the film peeled off 100 ℃ lower dry 4 hours and dry under 120 ℃-160 ℃ temperature with 10 ℃ interval subsequently, for dry 1 hour of each temperature, afterwards in vacuum dryer 180 ℃ lower dry 4 hours to obtain having the film of about 100 μ m thickness.(three-dimensional refractive index of the film that obtains is nx=1.5400, ny=1.5400 and nz=1.5400).

From this film, cut out the small pieces of 5cm * 5cm, and the unsupported width uniaxial tension that its experience is carried out under the condition of the draw speed of 220 ℃ temperature and 15mm/ minute with biaxial stretch-formed device (by Shibayama Scientific Co.Ltd. manufacturing).Thus film is stretched+50%, thereby obtain stretched film.The three-dimensional refractive index of the stretched film that obtains is nx4=1.53913, ny4=1.54042 and nz4=1.54045.

Although described the present invention in detail and with reference to embodiment, it will be apparent to one skilled in the art that and in the situation that does not deviate from the spirit and scope of the present invention, to carry out various changes and modifications.

The present invention is based on the Japanese patent application (application number 2007-109053) of the Japanese patent application (application number 2007-109052) of submitting on April 18th, 2007, submission on April 18th, 2007 and the Japanese patent application (application number 2007-331825) of submitting on Dec 25th, 2007, its content is hereby incorporated by.

Industrial applicability

According to the present invention, can provide optical compensating layer and optical compensation films with excellent optical.More specifically, can provide and have when the coating of coating fluid or during at the coating coating of fluid and uniaxial tension subsequently and give its optical compensation function and little optical compensating layer and the optical compensation films of wavelength dependence of its delay.

Claims

1. optical compensating layer, wherein this layer of compensation is the coating layer that comprises maleimide resin, and this coating layer is the film that does not stretch, wherein ought in the plane of this coating layer, be called respectively x axle and y axle by orthogonal two arbitrary axis, and when direction is called the z axle outside the plane, this coating layer capable of meeting requirements on three-dimensional index of refraction relationship nx ≈ ny＞nz

Wherein nx is the refractive index on the x direction of principal axis, and ny is the refractive index on the y direction of principal axis, and nz is the refractive index on the z direction of principal axis, and,

Described optical compensating layer has the plane external delays Rth of 30-2000nm, and wherein this plane external delays is represented by following formula (2) when the light with the measurement wavelength with 589nm detects:

Rth＝((nx+ny)/2-nz)×d (2)

Wherein d represents the thickness of this optical compensating layer, and unit is nm,

Described maleimide resin comprises the maleimide residue unit by the N-replacement of following formula (1) expression,

[changing 1]

R wherein ₁Expression has the straight chained alkyl of 1-18 carbon atom.

2. the optical compensating layer of claim 1, its have 1.1 or the wavelength dependence of lower delay be R450/R589, wherein the wavelength dependence of this delay by the delay R450 of the coating layer that tilts 40 degree and detect with the light of the measurement wavelength with 450nm with tilt 40 degree and represent with the ratio of the delay R589 of the coating layer of the light detection of the measurement wavelength with 589nm.

3. the optical compensating layer of claim 1, it is for being used for the optical compensating layer of liquid crystal display cells.

4. optical compensation films, it is to comprise the optical compensating layer of claim 1 and the stratiform product of the film made by celluosic resin.

5. the optical compensation films of claim 4, it is for being used for the optical compensation films of liquid crystal display cells.

6. make the method for each described optical compensating layer in the claim 1～3, it comprises and is coated in the substrate maleimide resin solution and dry coated solution.

7. method claimed in claim 6, wherein said maleimide resin solution is for comprising the solution by the maleimide resin of the maleimide residue unit of following general formula (1) expression:

[changing 2]

R wherein ₁Expression has the straight chained alkyl of 1-18 carbon atom.

8. optical compensation films, it comprises coating layer (A) and the stretch film layers (B) that comprises maleimide resin, and,

Described coating layer (A) has the plane external delays Rth1 of 30-2000nm, and wherein this plane external delays is represented by following formula (3) when the light with the measurement wavelength with 589nm detects:

Rth1＝((nx1+ny1)/2-nz1)×d1 (3)

Wherein d1 represents the thickness of this coating layer (A), and unit is nm,

Described maleimide resin comprises the maleimide residue unit that N-shown in the following general formula (1) replaces:

[changing 3]

R wherein ₁Expression has the straight chained alkyl of 1-18 carbon atom.

9. the optical compensation films of claim 8, wherein, when orthogonal two arbitrary axis in the plane of described coating layer (A) are called respectively x1 axle and y1 axle, and when direction is called the z1 axle outside the plane, so described coating layer (A) capable of meeting requirements on three-dimensional index of refraction relationship nx1 ≈ ny1＞nz1

Wherein nx1 is the refractive index on the x1 direction of principal axis, and ny1 is the refractive index on the y1 direction of principal axis, and nz1 is the refractive index on the z1 direction of principal axis.

10. the optical compensation films of claim 8, wherein, described coating layer (A) have 1.1 or the wavelength dependence of lower delay be R450/R589, wherein the wavelength dependence of this delay by the delay R450 of the coating layer that tilts 40 degree and detect with the light of the measurement wavelength with 450nm with tilt 40 degree and represent with the ratio of the delay R589 of the coating layer of the light detection of the measurement wavelength with 589nm.

11. the optical compensation films of claim 8, wherein, the in-draw direction is called the x2 axle when the plane of described stretch film layers (B), direction is called the y2 axle in the plane vertical with this draw direction, and direction is that thickness direction is when being called the z2 axle outside the plane of described stretch film layers (B), so described stretch film layers (B) capable of meeting requirements on three-dimensional index of refraction relationship nx2＞ny2 〉=nz2

Wherein nx2 is the refractive index on the x2 direction of principal axis, and ny2 is the refractive index on the y2 direction of principal axis, and nz2 is the refractive index on the z2 direction of principal axis,

Wherein said stretch film layers (B) has and postpones Re in 20nm or the larger plane, wherein postpones to be represented by following formula (4) in this plane when with the light detection of the measurement wavelength with 589nm:

Re＝(nx2-ny2)×d2 (4)

Wherein d2 represents the thickness of this stretch film layers (B), and its unit is nm.

12. the optical compensation films of claim 8, wherein, described stretch film layers (B) comprises and is selected from following at least a resin: polycarbonate resin, polyethersulfone resin, cyclic polyolefin resin and celluosic resin.

13 according to claim 8 The optical compensation film; wherein the optical compensation film in-plane slow axis direction of the x3-axis is called; with the x3-axis direction within a plane perpendicular axes referred to y3; plane and the film thickness direction, i.e., z3 axis direction is called; the film was measured at a wavelength of 589nm with a photodetector having a 1.1 or greater when the orientation parameter Nz; wherein the orientation parameter is presented by the following (5) means; wherein the x3 axis direction nx3 an average refractive index; ny3 y3 axis direction is an average refractive index; and nz3 z3 axis direction is an average refractive index

Nz＝(nx3-nz3)/(nx3-ny3) (5)。

14. the optical compensation films of claim 8, it is for being used for the optical compensation films of liquid crystal display cells.

15. make the method for each described optical compensation films in the claim 8～14, it comprises maleimide resin solution is coated in the upper and dry coated solution of stretch film layers (B) to become coating layer (A).

16. the described method of claim 15, wherein said maleimide resin solution are the solution that comprises the maleimide resin of the maleimide residue unit that is represented by following formula (1):

[changing 4]

R wherein ₁Expression has the straight chained alkyl of 1-18 carbon atom.

17. optical compensating layer, it is for to comprise the optical compensating layer that the coating layer of maleimide resin obtains by uniaxial tension, wherein the tensile axis direction in this coating layer is called the x4 axle, the direction vertical with this draw direction is called the y4 axle, and when direction is called the z4 axle outside the plane, this optical compensating layer capable of meeting requirements on three-dimensional index of refraction relationship nx4＞ny4＞nz4 so

Wherein nx4 is the refractive index on the x4 direction of principal axis, and ny4 is the refractive index on the y4 direction of principal axis, and nz4 is the refractive index on the z4 direction of principal axis, and

Described optical compensating layer has the plane external delays Rth2 of 30-2000nm, and wherein this plane external delays is represented by following formula (7) when the light with the measurement wavelength with 589nm detects:

Rth2＝((nx4+ny4)/2-nz4)×d4 (7)

Wherein d4 represents the thickness of this optical compensating layer, and its unit is nm,

Described maleimide resin comprises the maleimide residue unit by the N-replacement of following general formula (1) expression:

[changing 5]

R wherein ₁Expression has the straight chained alkyl of 1-18 carbon atom.

18. the optical compensating layer of claim 17 is characterised in that this optical compensating layer has and postpones Re1 in 20nm or the larger plane, wherein postpones to be represented by following formula (6) in this plane when with the light detection of the measurement wavelength with 589nm:

Re1＝(nx4-ny4)×d3 (6)

Wherein d3 represents the thickness of this optical compensating layer, and its unit is nm.

19. the optical compensating layer of claim 17, its have 1.1 or the wavelength dependence of lower delay be R450/R589, wherein the wavelength dependence of this delay is represented by the ratio of the delay R589 that measures under the delay R450 that measures under the measurement wavelength of 450nm and measurement wavelength at 589nm.

20. be used for the optical compensating layer of liquid crystal display cells, it comprises the optical compensating layer of claim 17.