CN100442092C - Optical film and liquid crystal display device - Google Patents

Abstract

The present invention relates to an optical film wherein fixing of liquid crystal alignment can be easily accomplished, which optical film can realize a wavelength dispersion of low birefringence and from the industrial point of view, is inexpensive and can be easily produced. The optical film enables accurate regulation of optical characteristics, such as wavelength dispersion of birefringence, to desired value and enables fixing of desired alignment state, being uniform and able to attain area expansion. In particular, an optical film comprising a polyester comprising structural units derived from 4-(4-carboxycyclohexyl)benzoic acid and structural units derived from an aromatic diol compound of ortho form, wherein the state of alignment created at thermal aligning of the polyester is fixed by cooling to temperature of not above the glass transition temperature.

Description

Optical thin film and liquid crystal display cells

Technical field

The present invention relates to easy, the birefringent wavelength dispersion of liquid crystal aligning immobilization little, be suitable for the optical thin film in optical elements such as phase-contrast film, used and with its circular polarizing disk, ellipsoidal polarizing plate and liquid crystal indicator.

Background technology

High molecule liquid crystal is in the heat-resisting high functional resin field that utilizes its high-fire resistance, mouldability etc. and utilize in the functional material field of liquid crystal aligning and just develop in active research.In heat-resisting high functional resin field, exploitation, commercialization in various fields such as electronic and electric components and automobile component, OAAV instrument component, encapsulant, have been obtained.On the other hand, in the functional material field, active development research is carried out in application in the phase-contrast film of using etc. at optical recording, non-linearity optical material, optical fiber, liquid crystal indicator etc., and the phase-contrast film that liquid crystal indicator is used etc. is all realized commercialization.

Phase-contrast film in liquid crystal indicators such as STN (super twisted nematic liquid crystal) mode and TFT (thin film transistor (TFT)) mode, is used to improve colorimetric compensation and visual angle.The phase-contrast film of using as general colorimetric compensation, can adopt oriented films such as polycarbonate, polyvinyl alcohol (PVA), polysulfones, polyethersulfone, amorphism polyolefin and utilize liquid crystal film of nematic liquid crystal etc., for improving the visual angle, can utilize the liquid crystal film of the hybrid orientation of nematic liquid crystal and dish type nematic liquid crystal.

The advantage of liquid crystal film can exemplify orientation order height, birefraction Δ n, compare with the polymeric materials such as polycarbonate that use in the stretched film very big, so when the phase-contrast film of the identical delay (Δ nd) of making, it is extremely thin that thickness can reach.For example, with in the phase-contrast film of polycarbonate, when making the film of delay Δ nd=400nm of wavelength 590nm, thickness also reaches 40～100 μ m, but the actual (real) thickness of part of bearing optical function in the liquid crystal film is at number μ m.Liquid crystal indicator majority before this is installed on the miniature instruments such as mobile phone, so also very high to the requirement of phase-contrast film, from the viewpoint of thin thickness, the superiority of liquid crystal film is big.

The material that uses in these phase-contrast films has wavelength dispersion (wavelength dependency) to birefringence.That is, as general tendency, the birefringence n of phase-contrast film depends on wavelength X as shown in the formula shown in (1):

Δn(λ)＝A+B/(λ ²-λ ₀ ²)(1)

In the formula, A, B are constant, λ ₀Represent the absorption edge wavelength in the common ultraviolet range.

As seen from formula (1), at λ=λ ₀, the curve that the dullness that birefringence n form to disperse reduces, measure the wavelength ratio shortwave grow up, littler than the long wavelength.When particularly being the zone line (メ ソ ゲ Application) that presents liquid crystal liquid crystal property as the molecular structure of liquid crystal material, absorption edge wavelength with the so long conjugated structure of phenyl ring or naphthalene nucleus or ester group, majority has the structure that is in long wavelength side, the wavelength dispersion of birefraction Δ n is big (promptly, measure the wavelength ratio short wavelength in short-term, birefringence is big), control ratio is easier to.In addition, when birefringence was big, wavelength dispersion also had the tendency of increasing usually.

For example, be in the polyester of long wavelength side structure as having the absorption edge wavelength, someone has proposed to import the liquid crystal polyester (spy opens flat 7-188402 communique, the spy opens flat 8-87008 communique) of the long 4-Hydroxycinnamic Acid unit of conjugated structure and the liquid crystal polyester (spy opens flat 7-179582 communique) that has imported p-phenylene diacrylate unit, and the wavelength dispersion of birefraction Δ n can be controlled significantly.In addition, the someone reports that birefraction also reaches 0.4 liquid crystalline polyester (spy opens flat 11-246652 communique, the spy opens flat 11-246750 communique) by import Stilbene (stibene) structure in high molecule liquid crystal.General known in liquid crystal material, n is big more as the birefraction Δ, then wavelength dispersion big more (the paper will C of electronic intelligence Communications Society, in September, 1988, Vol.J71-C, No.9, p.1241).

Before this, liquid crystal film mainly is used as the colorimetric compensation phase-contrast film of STN type liquid crystal indicator.STN type liquid crystal indicator is compared with the TFT type, has the slow shortcoming of response speed.What the response speed of STN-LCD and pond were thick square is inversely proportional to, so must reduce the thickness in pond when high-speed cruising.At this moment, must keep necessarily, so the low molecular weight liquid crystal that must use as the driving pond with the big liquid crystal of birefringence owing to drive the delay in pond.As discussed previously, the low molecular weight liquid crystal that birefringence is big is because wavelength dispersion is big, so in order all to obtain good compensation performance in the wavelength coverage, must make the wavelength dispersion of phase-contrast film also more consistent with the wavelength dispersion that drives the pond.Yet at the phase-contrast film of high-speed response type STN-LCD, as mentioned above, the liquid crystal film that wavelength dispersion is obviously controlled is preferred.

On the other hand, in mobile phone and PDA middle-size and small-size portable instruments such as (Portable information termainals), consider before this, can also use reflection-type Via Color TFT-LCD and semi-transmission type Via Color TFT-LCD from outdoor visuality and the electrical viewpoint of low consumption.These reflection-types, semi-transmission type Via Color TFT-LCD adopt the circularly polarized light mode more, as phase-contrast film, can use rectilinearly polarized light is transformed into circularly polarized light, circularly polarized light is transformed into the quarter wave plate of rectilinearly polarized light.In addition, as the quarter wave plate in this purposes, preferably the rectilinearly polarized light of visible light Zone Full is transformed into circularly polarized light, circularly polarized light is transformed into rectilinearly polarized light.Realize these requirements in order only to make with 1 phase-contrast film, it is preferred having little wavelength dispersion characteristic person, and the phase differential that it is desirable to measure in the wavelength X often reaches λ/4th, and is preferred.

In addition, the someone proposes to adopt 1 macromolecule stretched film, constitute to measure wavelength more at short wavelength side, and the film that delay diminishes (the international pamphlet that discloses No. 00/26705).Probably compare with common phase-contrast film such as polycarbonate, when making quarter wave plate, circularly polarized light-rectilinearly polarized light conversion characteristics at visible region is good, but measuring wavelength is long wavelength side and short wavelength side part, the wavelength dispersion characteristic is not satisfactory, so can not make quarter wave plate completely.In addition, the used thickness of stretched film is 80～140 μ m, reaches very thick.

In addition, the someone proposes method (spy opens flat 10-68816 communique) that the quarter wave plate that is made of commaterial and 1/2nd wavelength plates are fitted with suitable angle.The advantage that this method is very big is, wavelength dispersion is near desirable quarter wave plate, is the method for normal use at present, but owing to use 2 polycarbonate stretched film, considers it is disadvantageous from thickness, and room for improvement is big.In addition, the little person of the wavelength dispersion of material is preferred.

In the low molecular weight liquid crystal that use in the liquid crystal pond, when birefringent wavelength dispersion hour, it is effective to import cyclohexane structure.Because cyclohexane structure is non-conjugated structure, so absorption edge wavelength X 0 is in short wavelength side, therefore, can see that from following formula (1) wavelength dispersion diminishes.In addition, when considering the littler and liquid crystal liquid crystal property of birefringent wavelength dispersion etc., the cyclohexylbenzene structure is a preferred construction.As polyester, can enumerate the polyester (special public clear 47-31715 communique, special public clear 47-31953 communique) of (4-carboxyl cyclohexyl) the benzoic acid unit that has 4-with cyclohexylbenzene structure.But polyester disclosed herein does not have liquid crystal liquid crystal property, improves as the dyeability of the mass-produced polyethylene terephthalate of engineering plastics and inquires into, but mention wavelength dispersion is not any yet.

Therefore, in the prior art, present situation is to have little wavelength dispersion characteristic, and the example of the high molecule liquid crystal exploitation that is immobilized of liquid crystal aligning also do not have, and the example of discussion does not almost have yet.

The purpose of this invention is to provide a kind of liquid crystal aligning immobilization easily, can to realize that the birefringence wavelength disperses little, and can be cheap and the optical thin film that polyester constituted that easily make from industrial seeing.

Another purpose of the present invention provides and a kind ofly can correctly be adjusted to optical characteristics such as birefringent wavelength dispersion that desirable value, desirable state of orientation are immobilized, uniform large-area optical thin film.

Summary of the invention

The result that the inventor concentrates one's attention on to study to above-mentioned problem finishes the present invention.

That is, the present invention the 1st relate to by contain following general formula (a) and (b) expression structural unit the optical thin film that polyester constituted.

-O-W-O-(b)

(in the formula (b), W represents to be selected from the bivalent radical with in the base of following formula (w) expression, and substituent R b represents hydrogen atom, F, Cl, Br, CF ₃, phenyl, the alkyl of carbon number 1～5 or the alkoxy of carbon number 1～5, q is 1～4, in addition, formula (b) also can be made of different structural units more than 2 kinds).

The present invention the 2nd relates to above-mentioned optical thin film, it is characterized in that, above-mentioned polyester is liquid crystal liquid crystal property.

The present invention the 3rd relates to above-mentioned optical thin film, it is characterized in that, above-mentioned polyester by except that contain structural unit (a) and (b), also contain at least a kind with following formula (c), (d) and (e) polyester of expression structural unit constitute.

-O-Z-O-(e)

(in the formula (c), X represents to be selected from the bivalent radical with in the base of following formula (x) expression, and substituent R c represents hydrogen atom, F, Cl, Br, CF ₃, the alkyl of carbon number 1～5 or the alkoxy of carbon number 1～5, r is 1～4, in addition, formula (c) also can be made of different structural units more than 2 kinds, in the formula (d), Y represents to be selected from the bivalent radical with in the base of following formula (y) expression, and Rd represents hydrogen atom, F, Cl, Br, CF ₃, the alkyl of carbon number 1～5 or the alkoxy of carbon number 1～5, s is 1～4, m is 2～10, in addition, formula (d) also can be made of different structural units more than 2 kinds, in the formula (e), Z represents to be selected from the bivalent radical with in the base of following formula (z) expression, and Re represents hydrogen atom, F, Cl, Br, CF ₃, cyano group, the alkyl of carbon number 1～5 or the alkoxy of carbon number 1～5, t is 1～4, in addition, formula (e) also can be made of different structural units more than 2 kinds).

The present invention the 4th relates to above-mentioned optical thin film, it is characterized in that above-mentioned polyester by 1～45 mole of % of structural unit (a), (b) 1～45 mole of %, (c) 10～50 moles of %, (d) 0～44 mole of % and (e) is that the liquid crystalline polyester that constitutes of 0～44 mole of % is made.

The present invention the 5th relates to above-mentioned optical thin film, it is characterized in that the liquid crystalline polyester that constitutes of 1～49 mole of % is made by 1～50 mole of % of structural unit (a), (b) 1～49 mole of %, (c) 0～50 mole of %, (d) 0～49 mole of % and (e) for above-mentioned polyester.

The present invention the 6th relates to above-mentioned optical thin film, it is characterized in that, when being D with respect to the birefringence value (Δ n (450nm)) of measuring wavelength 450nm light with respect to the ratio of the birefringence value (Δ n (590nm)) of measuring wavelength 590nm light, D is in the scope of 1.00＜D＜1.12.

The present invention the 7th relates to above-mentioned optical thin film, it is characterized in that, with homogeneous phase orientation, the axially evenly in addition immobilization of any state of orientation of orientation, hybrid orientation, twisted nematic orientation or cholesteric orientation of pole-face.

The present invention the 8th relates to liquid crystal display cells, it is characterized in that, has at least 1 the of the present invention the 1st～the 7th any optical thin film.

The present invention the 9th relates to circular polarizing disk, it is characterized in that, has at least 1 the of the present invention the 1st～the 7th any optical thin film.

The present invention the 10th relates to ellipsoidal polarizing plate, it is characterized in that, has at least 1 the of the present invention the 1st～the 7th any optical thin film.

The present invention the 11st relates to liquid crystal display cells, it is characterized in that, has the of the present invention the 9th circular polarizing disk, or the 10th ellipsoidal polarizing plate.

Description of drawings

Fig. 1 is the liquid crystalline polyester of embodiment 1 ¹The measurement result of H-NMR spectrum.

Fig. 2 is the liquid crystalline polyester of embodiment 2 ¹The measurement result of H-NMR spectrum.

Fig. 3 is the liquid crystalline polyester of embodiment 7 ¹The measurement result of H-NMR spectrum.

Fig. 4 is the visual angle interdependence measurement result that postpones in the face of optical thin film when measuring wavelength 590nm of embodiment 24 and 25.

Embodiment

Optical thin film of the present invention, the structural unit (following structural unit (a) and the structural unit (b) of being called respectively) that reaches (b) expression with following formula (a) is as necessary structural unit, as required, at least by following formula (c), (d) and (e) polyester that constitutes of the arbitrary structures unit (following structural unit (c), structural unit (d) and the structural unit (e) of being called respectively) of expression formed.

Above-mentioned optical thin film, but both each homogenies of display optical, but each diversity of display optical again in addition, also can have zone that shows each homogeny and the zone that shows each diversity in the film.But, being considered as the optical element time spent, each diversity person of display optical is preferred.

For making above-mentioned optical thin film have optical anisotropy, must make the polyester orientation.As the way that makes orientation, can consider the method using the method for stretched film or utilize liquid crystal liquid crystal property etc., but when considering to make the optical thin film attenuation and realize various state of orientation, polyester of the present invention is the liquid crystalline polyester with mesomorphic state, is most preferred.

In addition, the orientation that makes above-mentioned polyester fixedly the person be preferred.As making the fixing method of orientation, can enumerate the method that the orientation that forms in liquid crystal phase is fixed as vitreousness; The method of being fixed by photo-crosslinking or heat cross-linking; The method that both share.By the crosslinked orientation that makes fixedly the time, can enumerate polyester end of the present invention and/or side chain and import and have reactive functional group, or the method for interpolation crosslinking chemical.

Below, the polyester with liquid crystal liquid crystal property that is suitable for the present invention's use is described in detail.

Polyester of the present invention is to reach the structural unit (following structural unit (a) and the structural unit (b) of being called respectively) of (b) expression as necessary structural unit by following formula (a) at least, as required, reach the backbone chain type polyester of arbitrary structures unit (following structural unit (c), structural unit (d) and the structural unit (e) of the being called respectively) formation of (e) expression by following formula (c), (d).By aromatic series or the alicyclic backbone chain type polyester that constitutes known have multiple, but, and show that the polyester of liquid crystal liquid crystal property do not inquire into fully for the synthetic backbone chain type polyester of ortho position aromatic diol compounds that from 4-(4-carboxyl cyclohexyl) benzoic acid and catechol is representative.

Structural unit (a) is the necessary composition that is used to present liquid crystal liquid crystal property and birefringent wavelength dispersion is diminished, and is the unit of deriving from 4-(4-carboxyl cyclohexyl) benzoic acid or its functional derivatives (for example dialkyl such as dimethyl ester and acyl chlorides such as diphenyl ester or dichloride etc.).

As the synthetic method of 4-(4-carboxyl cyclohexyl) benzoic acid, special public clear 47-31715 communique, special public clear 47-31953 communique etc. are on the books, adopt known method easily to be made.For example, 4,4 '-diester (for example dimethyl ester) of diphenyldicarboxylic acid, use catalyzer, by the part nuclear hydrogenation, make the diester of 4-(4-carboxyl cyclohexyl) benzoic acid, the hydrolysis by ester obtains again.As catalyzer, use nickel class catalyzer, or ruthenium, palladium, rhodium class catalyzer etc. are preferred.For add high surface area, make on the carriers such as loading on activated charcoal, zeyssatite, aluminium oxide, zeolite use also passable.Usually be that normal temperature～200 ℃, reaction pressure are that to synthesize under normal pressure～20MPa be preferred in temperature of reaction.

Polyester of the present invention, the ratio that contains structural unit (a) are 5～50 moles of %, preferred 15～45 moles of %, more preferably 20～40 moles of %.

Polyester of the present invention, structural unit (a) must structural unit with structural unit (b) conduct.Structural unit (b) is the necessary composition that as vitreousness the liquid crystal phase orientation is fixed down as cooling.W in the structural unit (b) represents to be selected from the divalent base with in the base of following formula (w) expression, and substituent R b represents hydrogen atom, F, Cl, Br, CF ₃, phenyl, the alkyl of carbon number 1～5 or the alkoxy of carbon number 1～5, q is 1～4, in addition, formula (b) also can be made of different structural units more than 2 kinds.

Preferred example as structural unit (b), can enumerate catechol, the 3-methyl catechol, the 4-methyl catechol, the 3-ethylcatechol, the 4-ethylcatechol, 3-n-pro-pyl catechol, 4-n-pro-pyl catechol, 3-isopropyl catechol, 4-isopropyl catechol, 3-normal-butyl catechol, 4-normal-butyl catechol, the 3-tert-butyl catechol, the 4-tert-butyl catechol, 3, the 5-ditertiarybutyl catechol, 4-n-pentyl catechol, 3-fluorine catechol, 4-fluorine catechol, 3,4-difluoro catechol, 3,4,5,6-tetrafluoro catechol, 3-chlorine catechol, 4-chlorine catechol, 3,4,5,6-tetrachloro catechol, 3-bromine catechol, 4-bromine catechol, 3,4,5,6-tetrabromo catechol, 4-phenyl catechol, 4-trifluoromethyl catechol, 3-methoxyl catechol, 4-methoxyl catechol, 3-tert-butoxy catechol, 4-tert-butoxy catechol, 2,3-naphthalene glycol, 1, the unit that 2-naphthalene glycol or various functional derivatives (for example diacetoxy compound etc.) are derived.

Polyester of the present invention, the ratio that contains structural unit (b) are 5～50 moles of %, preferred 15～45 moles of %, more preferably 20～40 moles of %.

Polyester of the present invention except that contain structural unit (a) and (b), also contain structural unit (c) as the arbitrary structures unit.Structural unit (c) is to help liquid crystal liquid crystal property to present and mesomorphic state stable structure unit.X in the structural unit (c) represents to be selected from the divalent base with in the base of following formula (x) expression, and substituent R c represents hydrogen atom, F, Cl, Br, CF ₃, the alkyl of carbon number 1～5 or the alkoxy of carbon number 1～5, r is 1～4, in addition, formula (c) also can be made of different structural units more than 2 kinds.

Preferred example as structural unit (c), can enumerate the 4-Para Hydroxy Benzoic Acid, 2-methyl-4-Para Hydroxy Benzoic Acid, 3-methyl-4-Para Hydroxy Benzoic Acid, 2,6-dimethyl-4-Para Hydroxy Benzoic Acid, 3,5-dimethyl-4-Para Hydroxy Benzoic Acid, 2-ethyl-4-Para Hydroxy Benzoic Acid, 3-ethyl-4-Para Hydroxy Benzoic Acid, 2-tertiary butyl-4-hydroxy benzoic acid, 3-tertiary butyl-4-hydroxy benzoic acid, 3,5-di-t-butyl-4-Para Hydroxy Benzoic Acid, 2-fluoro-4-Para Hydroxy Benzoic Acid, 3-fluoro-4-Para Hydroxy Benzoic Acid, 2,3-two fluoro-4-Para Hydroxy Benzoic Acids, 2,6-two fluoro-4-Para Hydroxy Benzoic Acids, 3,5-two fluoro-4-Para Hydroxy Benzoic Acids, 2,3,5,6-tetrafluoro-4-Para Hydroxy Benzoic Acid, 2-chloro-4-Para Hydroxy Benzoic Acid, 3-chloro-4-Para Hydroxy Benzoic Acid, 3,5-two chloro-4-Para Hydroxy Benzoic Acids, 2,3,5,6-tetrachloro-4-Para Hydroxy Benzoic Acid, 2-bromo-4-Para Hydroxy Benzoic Acid, 3-bromo-4-Para Hydroxy Benzoic Acid, 3,5-two bromo-4-Para Hydroxy Benzoic Acids, 2,3,5,6-tetrabromo-4-Para Hydroxy Benzoic Acid, 2-trifluoromethyl-4-hydroxy benzoic acid, 3-trifluoromethyl-4-hydroxy benzoic acid, 3,5-two (trifluoromethyl)-4-Para Hydroxy Benzoic Acid, 2-methoxyl-4-Para Hydroxy Benzoic Acid, 3-methoxyl-4-Para Hydroxy Benzoic Acid, 3,5-dimethoxy-4 '-Para Hydroxy Benzoic Acid, 2-ethoxy-4-Para Hydroxy Benzoic Acid, 3-ethoxy-4-Para Hydroxy Benzoic Acid, 3,5-diethoxy-4-Para Hydroxy Benzoic Acid, 2-tert-butoxy-4-Para Hydroxy Benzoic Acid, 3-tert-butoxy-4-Para Hydroxy Benzoic Acid, 6-hydroxyl-2-naphthoic acid, 4-hydroxyl-1-naphthoic acid, 4 '-hydroxyl-4-xenyl carboxylic acid, 2 '-fluoro-4 '-hydroxyl-4-xenyl carboxylic acid, 3 '-fluoro-4 '-hydroxyl-4-biphenyl carboxylic acids, 2-fluoro-4 '-hydroxyl-4-xenyl carboxylic acid, 3-fluoro-4 '-hydroxyl-4-xenyl carboxylic acid, suitable-right-coumalic acid, suitable-forulic acid, 4 '-hydroxy-4-methyl stilbene carboxylic acid, or the functional derivatives of this carboxylic acid (for example, acetoxyl group compound, alkyl ester compounds such as methyl esters or phenyl ester compound etc.) unit of deriving.

Polyester of the present invention, the ratio that contains structural unit (c) are 0～50 mole of %, preferred 0～40 mole of %, more preferably 0～35 mole of %.

Polyester of the present invention, except that contain structural unit (a) and (b), also contain the structural unit (d) of arbitrary structures unit.Structural unit (d) is as the structural unit that helps to present liquid crystal liquid crystal property and mesomorphic state stabilization.Y in the structural unit (d) represents to be selected from the divalent base with in the base of following formula (y) expression, and substituent R d represents hydrogen atom, F, Cl, Br, CF ₃, the alkyl of carbon number 1～5 or the alkoxy of carbon number 1～5, s is 1～4, in addition, formula (d) also can be made of different structural units more than 2 kinds.

As the preferred example of structural unit (d), can enumerate terephthalic acid (TPA), 2-fluorine terephthalic acid (TPA), 2,5-difluoro terephthalic acid (TPA), 2,3,5,6-tetrafluoro terephthalic acid (TPA), 2,6-difluoro terephthalic acid (TPA), 2,3,5,6-tetrafluoro terephthalic acid (TPA), 2-chlorine terephthalic acid (TPA), 2, the 5-dichloroterephthalicacid acid, the 2-bromo terephthalic acid, 2, the 5-dibromoterephthalic acid, 2-trifluoromethyl terephthalic acid (TPA), 2-methyl terephthalic acid (TPA), 2, the 5-dimethyl terephthalic acid, 2-methoxyl terephthalic acid (TPA), 2,5-dimethoxy terephthalic acid (TPA), m-phthalic acid, 2, the 6-naphthalenedicarboxylic acid, 1, the 4-naphthalenedicarboxylic acid, 4,4 '-the xenyl dicarboxylic acid, 2,2 '-dimethyl-4,4 '-the xenyl dicarboxylic acid, 3,3 '-dimethyl-4,4 '-the xenyl dicarboxylic acid, 3,3 ', 5,5 '-tetramethyl-4,4 '-the xenyl dicarboxylic acid, 1, the 4-cyclohexane dicarboxylic acid, 4,4 '-the stilbene dicarboxylic acid, 1, two (the 4-carboxyl phenoxy group) ethane of 2-, 1, two (the 4-carboxyl phenoxy group) propane of 3-, 1, two (the 4-carboxyl phenoxy group) butane of 4-, 1, two (the 4-carboxyl phenoxy group) pentanes of 5-, 1, two (the 4-carboxyl phenoxy group) hexanes of 6-, 1, two (the 4-carboxyl phenoxy group) heptane of 7-, 1, two (the 4-carboxyl phenoxy group) octanes of 8-, 1, two (the 4-carboxyl phenoxy group) nonanes of 9-, 1, two (the 4-carboxyl phenoxy group) decane of 10-, succinic acid, glutaric acid, hexane diacid, heptandioic acid, suberic acid, azelaic acid, decanedioic acid, 11 carbon diacid, dodecanedioic acid, 1,1 '-dicyclohexyl-4,4 '-unit that the functional derivatives (for example, dialkyl compound or diphenyl compounds such as dimethyl ester, chloride things such as dichloride etc.) of dicarboxylic acid or these carboxylic acids is derived.Particularly when birefringent wavelength dispersion hour, use 1,1 '-dicyclohexyl-4,4 '-dicarboxylic acid is preferred.

Polyester of the present invention, the ratio that contains structural unit (d) are 0～45 mole of %, preferred 0～35 mole of %, more preferably 0～30 mole of %.

Polyester of the present invention, except that contain structural unit (a) and (b), also contain the structural unit (e) of arbitrary structures unit.Structural unit (e) is as the structural unit that helps to present liquid crystal liquid crystal property and mesomorphic state stabilization.Z in the structural unit (e) represents to be selected from the divalent base with the base of following formula (z) expression, and substituent R e represents hydrogen atom, F, Cl, Br, CF ₃, cyano group, the alkyl of carbon number 1～5 or the alkoxy of carbon number 1～5, t is 1～4, in addition, formula (e) also can be made of different structural units more than 2 kinds.

As the preferred example of structural unit (e), can enumerate quinhydrones, the fluorine quinhydrones, 2,3-difluoro quinhydrones, 2,5-difluoro quinhydrones, 2,3,5,6-tetrafluoro quinhydrones, chlorohydroquinone, 2, the 3-dichloro hydroquinone, 2, the 5-dichloro hydroquinone, 2,3,5,6-tetrachloro quinhydrones, bromohydroquinone, 2,5-two bromohydroquinones, 2,3,5,6-tetrabromo quinhydrones, the trifluoromethyl quinhydrones, the cyano group quinhydrones, 2,3-dicyano quinhydrones, methylnaphthohydroquinone, 2, the 5-dimethyl hydroquinone, 2, the 6-dimethyl hydroquinone, 2,3, the 5-trimethylhydroquinone, 2,3,5, the 6-duroquinol, tertiary butylated hydroquinone, 2,5 di tert butylhydroquinone, 2, the 6-di-tert-butyl hydroquinone, 2,5-two amyl hydroquinone, the methoxyl quinhydrones, 2-methoxyl-5-methylnaphthohydroquinone, 2-methoxyl-6-methylnaphthohydroquinone, the tert-butoxy quinhydrones, 4,4 '-xenol, 2,2 ', 3,3 ', 5,5 ', 6,6 '-the octafluoro xenol, 3,3 ', 5,5 '-the tetra-tert xenol, 2,6-naphthalene glycol, 1,4-naphthalene glycol, 2-phenyl quinhydrones, 2,5-dihydroxy-4 '-methyl biphenyl, 1, the 4-cyclohexanediol, 1,1 '-dicyclohexyl-4,4 '-glycol, bisphenol-A (2,2 '-two (4-hydroxy phenyl) propane), bisphenol AF (2,2 '-two (4-hydroxy phenyl) HFC-236fa) or functional derivatives separately (for example, derivant such as the diacetoxy compound) unit of deriving etc.

Polyester of the present invention, the ratio that contains structural unit (e) are 0～45 mole of %, preferred 0～35 mole of %, more preferably 0～30 mole of %.

As preferred polyester of the present invention, can enumerate liquid crystalline polyester: 1～45 mole of % of structural unit (a), preferred 2～42 moles of %, more preferably 5～40 moles of % with following formation; (b) 1～45 mole of %, preferred 2～42 moles of %, more preferably 5～40 moles of %; (c) 10～50 moles of %, preferred 16～44 moles of %, more preferably 20～40 moles of %; (d) 0～44 mole of %, preferred 0～40 mole of %, more preferably 0～35 mole of %; (e) 0～44 mole of %, preferred 0～30 mole of %, more preferably 0～20 mole of %.

As another preferred polyester of the present invention, can enumerate liquid crystalline polyester: 1～50 mole of % of structural unit (a), preferred 5～50 moles of %, more preferably 10～50 moles of % with following formation; (b) 1～49 mole of %, preferred 5～45 moles of %, more preferably 10～40 moles of %; (c) 0～50 mole of %, preferred 0～44 mole of %, more preferably 0～40 mole of %; (d) 0～49 mole of %, preferred 0～45 mole of %, more preferably 0～40 mole of %; (e) 1～49 mole of %, preferred 5～45 moles of %, more preferably 10～40 moles of %.

Molecular weight of polyesters of the present invention is in phenol/tetrachloroethane mixed solvent (60/40 weight ratio), in the limiting viscosity [η of 30 ℃ of mensuration _Inh] be generally 0.05～2.0, preferred 0.07～1.0, more preferably 0.1～0.5.Work as η _InhValue had the worry of weakened less than 0.05 o'clock, had problems sometimes in the practicality.In addition, when being higher than 2.0, the flowability of mesomorphic state descends sometimes, has to be difficult to the worry that evenly is orientated.

In addition, polyester of the present invention is liquid crystal phase when fusion, and by being cooled to below the glass transition temperature, can make the orientation immobilization of this liquid crystal phase, is preferred therefore.When the orientation stability after the immobilization of consideration orientation, the glass transition temperature Tg of these polyester is being particularly preferred being preferred more than 40 ℃ more than 60 ℃, in addition, the upper limit is not particularly limited, and common is preferred below 300 ℃, is preferred below 200 ℃.When Tg is lower than 40 ℃, even the orientation immobilization of liquid crystal once produced, but lack in the reliability of high temperature, can not stablize and use as industrial materials sometimes.In addition, when Tg is higher than 300 ℃, be difficult to make liquid crystal to be orientated in desirable state of orientation.

Polyester of the present invention can obtain by the monomer component polycondensation corresponding to the said structure unit.Polymerization is not particularly limited, can adopts the known polymerization in this field, for example melt phase polycondensation or solution polymerization process synthesize.

When adopting the solution polymerization process synthesizing polyester, (for example as the formation monomer of ormal weight structural unit (a) that must composition, 4-(4-carboxyl cyclohexyl) benzoic acid) and the formation monomer of structural unit (b) (for example, the catechol diacetate esters), as the formation monomer of the structural unit (c) of any composition (for example, the acid of resting in peace of 4-acetoxyl group), the formation monomer of structural unit (d) (for example, terephthalic acid (TPA)), the formation monomer of structural unit (e) (for example, methylhydroquinone diacetate), in atmosphere of inert gases such as nitrogen, carry out the method for acetic acid that takes off of polymerization, can easily obtain the polyester of purpose in high temperature.

Polymerizing condition is not particularly limited normally 150～350 ℃ of temperature, preferred 200～300 ℃, reaction time more than 30 minutes, preferred about 1 hour～40 hours.In addition, wish that polyreaction carries out under normal pressure, but at the latter half of polymerization by decompression or be in and promote under the high vacuum that reaction is also passable.Also have, in order to promote polyreaction, amine such as 1-methylimidazole, 4-dimethylamino naphthyridine, alkali metal salt, Ti, Zn, Sn, Pb, Ge, V, As, Sb etc., or these slaines or metal oxide can be used singly or in combination.In addition, the molecular weight of polyester of the present invention can be controlled by controlling polymerization time and polymerization temperature, polymerization pressure etc., and common polycondensation reaction can easily be adjusted equally.

As an example that adopts solution polymerization manufactured polyester of the present invention, can enumerate the direct polymerization that adopts activator.For example, (for example as the formation monomer of ormal weight structural unit (a) that must composition, 4-(4-carboxyl cyclohexyl) benzoic acid) and the formation monomer of structural unit (b) (for example, catechol), as the formation monomer of the structural unit (c) of any composition (for example, the 4-Para Hydroxy Benzoic Acid), the formation monomer of structural unit (d) (for example, terephthalic acid (TPA)), the formation monomer of structural unit (e) (for example, methylnaphthohydroquinone) is dissolved in pyridine etc., in chlorination arylsulfonyl/dimethyl formamide or diphenyl phosphate chloride/dimethyl formamide as activating agent, making reaction about 1 hour～10 hours in 60～150 ℃ in the presence of the activating agent of enumerating, can easily obtain the polyester of purpose.

In addition, as another example that adopts solution polymerization manufactured polyester of the present invention, can enumerate the chloride method that makes the carboxylic acid activation.

Chloride method has several method, can enumerate high temperature solution polymerization method, low temperature solution polymerization method, interfacial polymerization etc.

In the high temperature solution polymerization method, for example, (for example as the formation monomer of ormal weight structural unit (a) that must composition, 4-(4-carboxyl cyclohexyl) benzoic acid acyl chlorides) and the formation monomer of structural unit (b) (for example, catechol), as the formation monomer of the structural unit (d) of any composition (for example, the terephthalic acid (TPA) dichloride), the formation monomer of structural unit (e) (for example, methylnaphthohydroquinone), in high boiling solvents such as neighbour-dichloro-benzenes, in 100～200 ℃ of reactions, can easily obtain the polyester of purpose.

In the low temperature solution polymerization method, above-mentioned monomer is dissolved in 1,2-ethylene dichloride, chloroform, 1,1,2, halogenated hydrocarbon solvent such as 2-tetrachloroethane or dimethyl sulfoxide (DMSO) (DMSO), dimethyl formamide (DMF), N-Methyl pyrrolidone (NMP) isopolarity solvent, tetrahydrofuran is (in the ether solvent such as THF), diox, in the presence of tertiary amines such as triethylamine that is held agent as acid or tripropyl amine (TPA) or pyridine, near-10 ℃～room temperature, react, can easily obtain the polyester of purpose.

In interfacial polymerization, preferably adopt organic solvent-aqueous alkali two phase systems.Aromatic diol is dissolved in aqueous alkalis such as NaOH or potassium hydroxide, the aromatic dicarboxylic acid chloride is dissolved in 1,2-ethylene dichloride, chloroform, 1,1,2, in the halogenated hydrocarbon solvents such as 2-tetrachloroethane, near room temperature, carry out high degree of agitation, can easily obtain the polyester of purpose.At this moment, be the salt alternate moving catalysts such as (ammonium salt, clock Yan, phosphonium salt, sulfonium salts) of representative by adding tertiary amine or ammonium chloride, can improve polymerism.

The above-mentioned polyester of the present invention that obtains owing to the differences such as ratio of components of the structural unit that constitutes this polyester cannot treat different things as the same, but under common mesomorphic state, can form nematic phase or dish shape phase.In addition, this polyester that is in mesomorphic state is during with cooling velocity cooling arbitrarily, phase transfer to crystallizing layer does not take place in fact, below glass transition temperature, molecular orientation state in the mesomorphic state, concrete at nematic phase, the dish shape molecular orientation state in mutually, have the feature that former state keeps.In addition, polyester of the present invention can mix with other liquid crystal liquid crystal property macromolecules, non-liquid crystal liquid crystal property macromolecule etc., uses as composition and also can.In addition, in this polyester, cooperate low molecule of optical activity or polymer substance, make composition, also can obtain having the liquid crystalline composition of chiral nematic phase (cholesterol phase) as liquid crystal phase.

Polyester of the present invention, but by the character that the molecular orientation state former state of utilizing in the mesomorphic state keeps, can obtain the optical thin film that the orientation of nematic phase or dish shape phase is fixed.As an example, can obtain homogeneous phase orientation, the axial even optical thin film that is fixed of orientation, hybrid orientation, tilted alignment, π orientation, twisted nematic orientation or cholesteric orientation of pole-face.

Shown in one of manufacture method of this optical thin film is for example following.The orientation substrate that uses following explanation at first, in the present invention is preferred.As orientation substrate, concrete can enumerate polyimide, polyamidoimide, polyamide, polyetherimide, polyetheretherketone, polyetherketone, the polyketone sulfoxide, polyethersulfone, polysulfones, polyphenylene sulfide, polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, PEN, polyacetal, polycarbonate, polyacrylate, acryl resin, methacrylic resin, polyvinyl alcohol (PVA), tygon, polypropylene, poly--4-methylpentene-1 resin, norbornene resin, cellulose family plastics such as triacetyl cellulose, epoxy resin, phenolics, plastic foil substrates such as high molecule liquid crystal; Metal substrates such as aluminium, iron, copper; Glass substrates such as blue or green glass sheet, alkali glass, alkali-free glass, pyrex, printed glass, quartz glass; Various substrates such as ceramic substrate; Various semiconductor substrates such as silicon wafer etc.In addition, other overlay films are set on aforesaid substrate, organic membrane such as polyimide film, polyamide membrane, polyvinyl alcohol film for example, or be provided with that to use behind the monox icocline vapor-deposited film be preferred.Also have, above-mentioned plastic foil substrate preferably carries out single shaft or biaxial stretch-formed.

To the implementation orientation processing as required of these various substrates.As the method that various substrate implementation orientations are handled, for example can enumerate rubbing manipulation, oblique vapour deposition method, fine groove method, stretching macromolecule embrane method, LB film (blue Mil-injection) method, transfer printing, luminescence method (photoanisotropy, photopolymerization, photolysis etc.), peel off method etc.Particularly consider that from the easy degree of manufacturing process in the present invention, rubbing manipulation, luminescence method are desirable.

Optical thin film of the present invention is evenly obtaining through the immobilization process of even orientation process, state of orientation behind the coated polyester on the aforesaid substrate.The coating of this polyester on orientation substrate usually is dissolved in solution state in all kinds of solvents or the state of said composition fusion carries out in said composition.Consider that from manufacturing process it is preferred adopting polyester to be dissolved in the solution coat method that the solution in the solvent is coated with.

Below the solution coat method is illustrated.

At first, polyester of the present invention is dissolved in the solvent, is mixed with the solution of normal concentration.The thickness of film (thickness of the layer that forms by polyester), by this polyester coated step decision on substrate, therefore, must accurate control concentration and the thickness of coated film etc.As above-mentioned solvent, because of polyester ratio of components of the present invention etc. different, cannot treat different things as the same, but can adopt chloroform usually, methylene chloride, phenixin, ethylene dichloride, tetrachloroethane, triclene, zellon, chlorobenzene, halogenated hydrocarbons such as o-dichlorobenzene, phenol, phenol such as parachlorophenol, benzene, toluene, dimethylbenzene, methoxybenzene, 1, arenes such as 2-dimethoxy benzene, isopropyl alcohol, alcohols such as the tert-butyl alcohol, glycerine, ethylene glycol, glycolss such as triethylene glycol, glycol monoethyl ether, diethylene glycol dimethyl ether, ethyl cellosolve, glycol ethers such as butyl cellosolve, acetone, MEK, ethyl acetate, 2-Pyrrolidone, the N-N-methyl-2-2-pyrrolidone N-, pyridine, triethylamine, tetrahydrofuran, dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide (DMSO), acetonitrile, butyronitrile, carbon disulphide, and their mixed solvent etc.Surface tension, raising coating performance in order to adjust solution can add surfactant as required in these solvents.Surfactant is not particularly limited, and is preferred but use the surfactant of type siloxane or fluorine class.

The concentration of solution depends on the thickness of the polyester dissolubility of use and final purpose liquid crystal layer and decides, and cannot treat different things as the same, but uses in 3～50 weight % scopes usually, preferred 5～30 weight % scopes.Be adjusted to the polyester liquid of desirable concentration with above-mentioned solvent, be coated on the above-mentioned orientation substrate with following method.As coating process, can adopt daraf(reciprocal of farad) on method of spin coating, roller rubbing method, print process, the dipping, curtain rubbing method, mayer rod rubbing method, scraper rubbing method, pocket knife rubbing method, mould rubbing method, photogravure rubbing method, miniature photogravure rubbing method, hectograph photogravure rubbing method, otch rubbing method, spraying process etc.The coating back is removed and is desolvated, and forms the said composition layer of homogeneous film thickness on orientation substrate.Be not particularly limited removing the condition desolvate, usually in drying at room temperature, at kiln dried, blow warm braw or heated-air drying etc. and remove and desolvate.

After the drying, usually heat-treat, make this polyester orientation in the mesomorphic state at 50 ℃～300 ℃, preferred 100 ℃～200 ℃ scope.In addition, heat treatment time is different because of the ratio of components of polymer blend, cannot treat different things as the same, but common 10 seconds～120 minutes, preferred 30 seconds～60 minutes scope.When being less than 10 seconds, the even orientation in the mesomorphic state has insufficient worry.And, the worry of productivity decline is arranged when greater than 120 timesharing, be not preferred.Therefore, at first to obtain the even orientation of mesomorphic state on whole orientation substrate.Also have, in the present invention,, evenly be orientated, also can utilize magnetic field or electric field for making polyester at above-mentioned heat treatment step.

The even orientation that forms by thermal treatment then by being cooled to this temperature below polyester glass transition temperature, can be orientated under the inhomogeneity situation and fixed not damaging this fully.Above-mentioned chilling temperature so long as the following temperature of glass transition temperature gets final product, and is not particularly limited.For example, be cooled to, even orientation is fixed than the temperature of low 10 ℃ of glass transition temperature or room temperature etc.Way to cooling is not particularly limited, and from the heating atmosphere gas of heat treatment step, in the atmosphere gas below the glass transition temperature, is for example fixed in the room temperature.In addition, for enhancing productivity, air cooling, water-cooled etc. are forced cooling, slowly cooling all can.Adopt above-mentioned operation, can obtain optical thin film of the present invention.

As the use-pattern of this optical thin film, can enumerate:

(1) aforesaid substrate is peeled off from this film, in the liquid crystal layer monomer, used;

(2) with the directly use of the formation state on substrate;

(3) behind stacked liquid crystal layer on another substrate different, use etc. with substrate.

When as the liquid crystal layer monomer, can adopt the method for carrying out mechanical stripping at the interface of substrate and liquid crystal layer with roller etc., carry out the method for mechanical stripping, in poor solvent, utilize method that ultrasound wave peels off, utilize method that substrate and the alignment films dissolving on method, substrate itself or the substrate that the thermal expansivity official post temperature variation of this film is separated remove etc., obtain the film monomer after the entire infrastructure material soaking is in poor solvent.Fissility is different with the adaptation of substrate because of the ratio of components of used polyester etc., so must adopt only method in this system.

Be illustrated when secondly, the state that forms on the substrate being adopted optical thin film down.Substrate is transparent and optical isotropy, or when this substrate is necessary parts to this element when using as optical thin film, and it can be directly uses as the optical thin film of purpose.

In addition, the optical thin film of the present invention that obtains after the polyester orientation is fixed from this strippable substrate, also can in other substrate upper strata poststack use that optics is suitable for.As concrete Production Example, can adopt following method.Liquid crystal layer on the substrate (calling the 1st substrate in the following text) and the substrate (calling the 2nd substrate in the following text) that is suitable for doing the purpose optical thin film, for example paste with bonding agent or bonding agent.Then,, this film is transferred to the 2nd substrate-side that is suitable for doing optical thin film, can obtains optical thin film at liquid crystal layer interface peel the 1st substrate of the present invention.

The 2nd substrate that uses during as transfer printing as long as have the planarity of appropriateness, and is not particularly limited, and is preferred but adopt glass substrate or the transparent optically isotropic plastic sheeting that has.As such plastic sheeting example, it is preferred can enumerating polymethylmethacrylate, polystyrene, polycarbonate, polyethersulfone, polysulfones, polyimide, polyphenylene oxide, polyacrylate, amorphous polyolefins, polyethylene terephthalate, tri acetyl cellulose, norbornene resin or epoxy resin etc.Wherein, polymethylmethacrylate, polycarbonate, polyacrylate, polyethersulfone, tri acetyl cellulose, norbornene resin etc. are preferred.In addition, although be optical anisotropy, concerning optical thin film, during as the parts of necessity, optical anisotropic film also can use.As this example, have before to enumerate and adopt single shaft or the biaxial stretch-formed resulting phase retardation film of plastic sheeting, the liquid crystal film that is fixed with the same various mesomorphic states orientations of the present invention, polarizing film etc.

Bonding agent or the bonding agent pasted as the 2nd substrate that is used for transfer printing and liquid crystal layer of the present invention, optical-grade is preferred, can use acrylic compounds, epoxies, ethylene-vinyl acetate copolymer class, rubber-like, polyurethanes and their mixed system.In addition, as bonding agent, any bonding agents such as thermohardening type, light-cured type, electronics line curing type are as long as have that optical isotropy all can be used and no problem.Liquid crystal layer of the present invention is at the printing transferring method that is suitable for doing on the 2nd substrate of optical thin film, ties up to the 2nd base plate bonding after on the liquid crystal layer, carries out at interface peel the 1st substrate of this liquid crystal layer.Stripping means, as mentioned above, can enumerate the method that adopts roller etc. to carry out the method for mechanical stripping, in poor solvent, utilize method that ultrasound wave peels off, utilize orientation substrate and the alignment films on method, the 1st substrate itself or the 1st substrate that the thermal expansivity official post temperature variation of this film is separated to dissolve to remove etc.Fissility is different with the adaptation of the 1st substrate because of the ratio of components of used polyester etc., so must adopt only method in this system.As the spy who uses these technology opens the record of flat 8-278491 communique like that, by employing releasable substrate on the 2nd substrate, can finally obtain the optical thin film that the 2nd substrate is removed form, can extremely thin viewpoint see it is preferred from optical thin film.

In addition, optical thin film of the present invention, for surface protection, gain in strength, improve purposes such as environmental reliability, it is also passable that protective seams such as transparent plastic sheeting or photocuring film are set in addition.

As the optical parametric of the invention described above optical thin film feature, can enumerate the wavelength dispersion value of length of delay (Δ nd), film thickness direction length of delay (Δ nd) and birefringence n in thickness d, the face etc.These optical parametrics, different because of the purposes of this film, cannot treat different things as the same, but, be generally the scope of 0.1 μ m～20 μ m, the scope of preferred 0.2 μ m～15 μ m, the scope of preferred especially 0.3 μ m～10 μ m as thickness d.

When liquid crystal molecule evenly was orientated with respect to face, length of delay was with respect to 590nm monochromatic light, usually in the scope of the scope of the scope of 10nm～4000nm, preferred 20nm～2000nm, preferred especially 50nm～1000nm in the face.Here length of delay in the so-called face is meant the interior birefraction of face of film and the product (Δ nd) of thickness.

When liquid crystal molecule carries out axial high preferred orientation with respect to face, the length of delay of film thickness direction, with respect to 590nm monochromatic light, the scope of common scope, preferred 20nm～2000nm, the scope of preferred especially 50nm～1000nm at 10nm～4000nm.Here so-called film thickness direction length of delay is meant the product (Δ nd) of film thickness direction birefraction (film thickness direction refractive index and face in refractive index poor) and thickness.

In addition, the wavelength dispersion value of birefringence n, with defining of following formula (2) expression with respect to the birefringence value (Δ n (450nm)) of measuring wavelength 450nm light and the D value represented with respect to the ratio of the birefringence value (Δ n (590nm)) of measuring wavelength 590nm light:

D＝Δn(450nm)/Δn(590nm)(2)

The D value of polyester of the present invention, mainly by the amount domination that imports 4-(4-carboxyl cyclohexyl) the benzoic acid unit in the polymkeric substance, be generally 1.00＜D＜1.12, preferred 1.02＜D＜1.10, the more preferably scope of 1.04＜D＜1.09, when the amount of 4-(4-carboxyl cyclohexyl) benzoic acid unit increased, the D value diminished.But polyester of the present invention can freely be controlled the D value by the amount of control 4-(4-carboxyl cyclohexyl) benzoic acid unit.

In optical thin film of the present invention, by cooperating low molecule of optical activity or polymer substance again, can make the optical thin film that the distorted-structure of twisted nematic orientation and cholesteric orientation is fixed in the polyester of the present invention.The optical thin film that twisted nematic orientation is fixed can be used for the optical compensating film of LCD etc., and the optical thin film that the cholesteric orientation is fixed can utilize the characteristic of selecting the reflection circle polarisation.Twisted nematic orientation or cholesteric orientation have this point of torsional deformation to see internally, and think same in essence state of orientation, because of the degreeof tortuosity difference, resulting effect difference is distinguished thus.

The optical thin film that twisted nematic orientation of the present invention or cholesteric orientation are fixed is as the optical parametric of feature, except that length of delay (Δ nd) in the thickness d that had before enumerated, face, and the wavelength dispersion value of birefringence n, can also enumerate twist angle (rotation number of distortion).

In the optical thin film that twisted nematic orientation is fixed, twist angle is the scope of (equivalent with 2 rotations) below 720 degree more than 0 degree usually, preferably in the scope of above 540 degree of 0 degree following (equivalent) with 1.5 rotations, the scope of above 360 degree of preferred especially 0 degree following (with rotating equivalence 1 time).Also have, in optical thin film of the present invention, form the direction of orientation vector of the liquid crystal molecule of this film, change successively at the film thickness direction of film.But, said twist angle in the optical thin film of the present invention, be from a face of liquid crystal layer between the another side, making the viewpoint definition of this orientation vector rotation is twist angle.By the relation of suitable adjustment twist angle and thickness, can be used as and utilize twist structured phase retardation film to use.

Equally, in the optical thin film that the cholesteric orientation is fixed, twist angle is the scope of (equivalent with 20 rotations) below (equivalent with 1 rotation) 7200 spent more than 360 degree usually, preferably in the scope of 540 degree above (equivalent) 5400 degree following (equivalent) with 15 rotations with 1.5 rotations, the scope of preferred especially 360 degree above (equivalent) 3600 degree following (with rotating equivalence 10 times) with 1 rotation.Have the optical thin film of selecting this rotatory polarization character of reflection can be separately or make up with 1/4 wavelength plate after the liquid crystal display cells of packing into, can be used as color polarizing plate or cholesteryl liquid crystal polaroid whereby.

In optical thin film of the present invention, polyester of the present invention is independent, or cooperates other low molecule or polymer substances, also can make the optical thin film that hybrid orientation is fixed.The so-called hybrid orientation here is meant the orientation vector level of approximation orientation of 1 face of liquid crystal layer, but near the orientation vector of another side, the structure that slowly tilts facing to face.In other words, the size of the projection vector on the direct face of liquid crystal molecule has the structure that changes at film thickness direction.

The optical thin film that hybrid orientation of the present invention is fixed is the optical parametric of feature, except that the thickness d that had before enumerated, when the film normal direction is observed in the face the wavelength dispersion value of length of delay (Δ nd) and birefringence n, can enumerate from the film normal direction to above-mentioned projection vector direction, the ratio of length of delay in length of delay and the face when the angle of film normal direction is observed in the face when angles that tilt from 40 degree are observed (Δ nd than).In the optical thin film that hybrid orientation is fixed, because of orientation vector changes continuously at film thickness direction, thus be difficult to direct quantitative, so with above-mentioned Δ nd ratio.At this moment, length of delay has two values of size in the face when 40 degree angles of film normal direction are observed, but big value is used in definition.

This Δ nd than common more than 0.85 below 1.5, preferred more than 1 below 1.4, more preferably more than 1.1 below 1.35.

The optical thin film of the invention described above, orientation characteristic is good certainly, and the glass immobilization of liquid crystal aligning is easy, and the hold facility excellence of liquid crystal aligning state.But, require the various optical elements of high temperature durability, for example in improving with purposes such as film, colorimetric compensation film, optically-active element film, cholesteric polarizer, phase retardation film, visual angle can extensively adopt.

In addition, optical thin film of the present invention by stacked with polaroid, can be made into circular polarizing disk and ellipsoidal polarizing plate.When making circular polarizing disk, the ellipticity of wavelength 550nm more than 0.7, preferred more than 0.8, more preferably more than 0.9.In addition, this moment, optical thin film of the present invention both can be 1, also can be stacked more than 2.For example, when being the circular polarizing disk of broad band region, 2 optical thin films with phase differential of 1/4 wavelength and 1/2 wavelength also can be stacked.At this moment, both can use 2 all to be optical thin film of the present invention, also can use 1 single shaft or biaxial stretch-formed above-mentioned plastic sheeting.In addition, as optical thin film, when employing has the hybrid orientation optical thin film, also can be used as the improved circular polarizing disk of viewing angle characteristic with 1/4 wavelength phase differential.

In addition, these circular polarizing disks or ellipsoidal polarizing plate can use in various devices such as liquid crystal indicator and organic EL display.Particularly polaroid is configured in one or both sides, liquid crystal pond and forms reflection-type or the various liquid crystal indicators of semi-transmission type, infiltration type, or to be used as antireflection etc. in the organic EL display be preferred.Also have, when circular polarizing disk of the present invention or ellipsoidal polarizing plate are installed on the liquid crystal pond, parameters such as length of delay and with the angle of reporting to the leadship after accomplishing a task of polaroid, in the liquid crystal pond of optical compensation,, can make the good display device of characteristic by suitably adjusting.

Below preferred plan of the present invention is implemented in explanation.

Enumerate embodiment below, specifically describe the present invention, but the present invention is not limited by these embodiment.The various analytical approachs of using among the embodiment are as follows.

(1) mensuration of limiting viscosity

Adopt Ubbelohde type viscosity meter, in phenol/1,1,2, in 2-tetrachloroethane (60/40 weight ratio) mixed solvent, polymer concentration 0.5g/dL measures in 30 ℃.

(2) affirmation of chemical constitution

Liquid crystalline polyester is dissolved in the heavy-hydrogenated trifluoroacetic acid, with 400MHz's ¹H-NMR (バ リ ァ Application is made, UNITY INOVA 400MHz) measures.

(3) mensuration of glass transition temperature (Tg)

The DSC-7 that makes with Perkin Elmer company measures.

(4) optical texture is observed

The ホ ッ ト ス テ one ジ FP80/82 and the Ou Lin Bath Optical Co., Ltd that make with メ ト ラ one company make, and the BH2 polarizing microscope is observed.

(5) mensuration of refractive index

(ァ go company makes, and Type-4), measures refractive index with NaD line (measuring wavelength 590nm) with Abbe refractometer.

(6) birefringent wavelength dispersion is measured

After on glass the heat-treating of the alignment film of polyimide that rub of band, cool off, as the film sample that the orientation of vitreousness is fixed, measure the delay of each wavelength, each wavelength monochromatic light of employing monochrometer ejaculation is measured with セ Na Le モ Application method.The data that obtain are carried out match with the コ one シ same form obtain wavelength dispersion.In addition, because birefringent wavelength dispersion value is easy to comparison, by with the defining of following formula (2) expression, obtain the D value with respect to the birefringence value (Δ n (450nm)) of measuring wavelength 450nm light with respect to the ratio of the birefringence value (Δ n (590nm)) of measuring wavelength 590nm light.

(7) mensuration that postpones in twist angle and the face

Linear polarization is incided on the film, and (company of ditch buttocks optics industry institute makes, and DVA-36VWLD) carries out the polarisation analysis to seeing through light, at twist angle and measure wavelength 590nm and obtain in the face and postpone with ellipsograph.In addition, the KOBRA-21ADH that uses prince's instrumentation machines corporation to make is measuring wavelength 590nm, during from embrane method line direction and oblique observation, postpones in the mensuration face, confirms evenly orientation or hybrid orientation.When being hybrid orientation, the ratio of length of delay in the face of observing from the angle of embrane method line direction 40 degree and observing from the angle of embrane method line direction is defined as Δ nd ratio.At this moment, there are two values of size in length of delay in the face when observing from the angle of spending from embrane method line direction 40, but uses big value.

(8) mensuration of thickness

The surface-profile measuring instrument Dektak 3030ST type that adopts Japanese vacuum technique company to make.In addition, obtain the method and the usefulness of thickness from the mensuration of interference wave (Japanese beam split company make UV, visible light near infrared spectrometer V-570) and refractive index data.

Embodiment 1

4-(4-carboxyl cyclohexyl) benzoic acid 100mmol, methylhydroquinone diacetate 50mmol and catechol diacetate esters 50mmol, band acetic acid at 200ml flows out with in the flask of cooling tube, flow down at nitrogen, in 270 ℃ 6 hours, then under this temperature, flow down and carry out taking off in 2 hours the acetic acid polymerization with 30ml/ minute nitrogen.The polymer dissolution that obtains in tetrachloroethane, is added refining polymkeric substance in a large amount of methyl alcohol.The limiting viscosity of this polyester is 0.18dL/g, has nematic phase as liquid crystal phase, and each homogeny phase-liquid crystal phase transition temperature is more than 300 ℃, and glass transition point is 115 ℃.Fig. 1 illustrates ¹H-NMR spectrum.In addition, from the result of polarized light microscope observing as can be known, below glass transition temperature, nematic liquid crystal phase orientation is completely fixed.

Secondly, phenol/tetrachloroethane (60/40 weight ratio) mixed solvent solution of 8 weight % of preparation polyester.With method of spin coating this solution coat is had on the friction polyimide film, on hot plate in 55 ℃ of dryings 20 minutes., take out from the baking oven that cleans after 20 minutes in 220 ℃ of thermal treatments in the baking oven of cleaning, the natural air cooling obtains the optical thin film that nematic state of orientation is fixed.Resulting optical thin film is transparent and do not have an orientation defective.The measurement result of refractive index is n0=1.539, ne=1.680, Δ n=0.141.The result of optical detecting is that evenly orientation is fixed for the liquid crystal layer in the optical thin film, sees from embrane method line direction to postpone to be 170mm in the face.The D value of this polymkeric substance is 1.099.

Embodiment 2～16 and comparative example 1

Outside demonomerization kind and adding proportion change, adopt method similarly to Example 1 to study.The results are shown in table 1.In addition, the polymkeric substance of embodiment 2 ¹H-NMR spectrum is shown in Fig. 2, the polymkeric substance of embodiment 7 ¹H-NMR spectrum is shown in Fig. 3.These polyester all show uniform nematic liquid crystal phase more than glass transition temperature, and even be cooled to the transfer to the row crystallization phase also unconfirmed below the glass transition temperature, the state of orientation that forms mutually at nematic liquid crystal is fixed.

Embodiment 17

Phenol/tetrachloroethane (60/40 weight ratio) mixed solvent solution of 8 weight % of the polyester that preparation embodiment 7 obtains.This solution is coated with method of spin coating in that element is on glass, on hot plate in 55 ℃ of dryings 20 minutes., take out from the baking oven that cleans after 20 minutes in 220 ℃ of thermal treatments in the baking oven of cleaning, the natural air cooling obtains the optical thin film that nematic state of orientation is fixed.Resulting optical thin film is transparent and do not have an orientation defective.The result of viewing optics film is under the intersection Niccol, does not observe phase differential in the face during from top view, and phase differential takes place during from oblique observation.The result who carries out the interferometer observation with polarizing microscope observes cross shape, and in addition, the result who inserts the observation of 1/4th wavelength plates is that the 2nd quadrant, the 4th quadrant are viewed as black.From above result as can be known, the liquid crystal layer in the optical thin film evenly is fixed to the row orientation.The result of detecting refractive index is the refractive index 1.535 of direction in the face, the refractive index 1.657 of film thickness direction, and the measurement result of thickness is 2.0 μ m, and film thickness direction postpones to be 244nm.

Synthesis example 1

In the polymer reactor that stirring apparatus, nitrogen ingress pipe, liquid trap are housed, pack 4 into, 4 '-diphenyldicarboxylic acid dimethyl ester 90mmol, dimethyl terephthalate (DMT) 10mmol, (S)-2-methyl isophthalic acid, 4-butylene glycol (enantiomeric exess, e, e=93%) 120mmol and four titanium butoxide are 1, in the nitrogen replacement reactor.The limit steams the methyl alcohol of generation in nitrogen atmosphere gas, and the limit obtains optically active polyester in 210 ℃ of reactions 2 hours.The limiting viscosity of this optically active polyester (polyester A) is 0.12dL/g.

Synthesis example 2

Except using the 2-methyl isophthalic acid of raceme, beyond the 4-butylene glycol, react equally with synthesis example 1, obtain optics inertia polyester.The limiting viscosity of this optics inertia polyester (polyester B) is 0.12dL/g.

Embodiment 18

The polymer A 0.20g that polymkeric substance 19.80g that embodiment 3 is used and synthesis example 1 obtain is dissolved in the N-N-methyl-2-2-pyrrolidone N-of 80g and is mixed with solution.For to make it that good coating be arranged, add fluorine class surfactant (company of big Japanese ink company makes, メ ガ Off ァ ッ Network F142D) 0.02g (is 0.1 weight % with respect to total polymer) here.This solution is coated with method with rod is coated in (caprone that デ ヱ Port Application company makes) on the polyimide film of crossing with rayon cloth friction treatment, in the baking oven of cleaning in 55 ℃ of dryings remove desolvate after, in 210 ℃ of thermal treatments 20 minutes, form the twisted nematic orientation structure again.After the thermal treatment, take out from baking oven, natural cooling, the twisted nematic orientation structure is with vitreousness be cured (film 1).

Also have, in order to obtain the birefringent wavelength dispersion value D of this film 1, make the polymkeric substance 19.82g of embodiment 3 uses and the polymer B 0.18g that synthesis example 2 obtains, be dissolved in the N-N-methyl-2-2-pyrrolidone N-of 80g, operation similarly to Example 1, make the optical thin film of the inhomogeneous orientation of distortion, the result who obtains the D value is D=1.076, and is same with the value of embodiment 3.

Because film 1 forms on opaque and optically anisotropic polyimide film, so can not directly use as optical thin film.Therefore; air interface side coating UV curing adhesive (East Asia Synesis Company manufacturing at film 1; UV-3400) about 5 μ m are thick; (description film company of Fuji makes the tri acetyl cellulose film of each homogeny film of optics of lamination 80 μ m thereon; Off ジ ッ Network T80SZ); by shining the UV of about 600mJ, this bonding agent is solidified.Then, peel off polyimide film, liquid crystal layer is transferred on the tri acetyl cellulose membrane from tri acetyl cellulose membrane/adhesive phase/liquid crystal layer/polyimide film all-in-one-piece layered product.In addition, to the liquid crystal layer surface coated UV curing adhesive of peeling off the polyimide film side (East Asia Synesis Company makes, and UV-3400) about 5 μ m are thick, in the oxygen barrier state down the UV light (high-pressure sodium lamp) of the about 600mJ of irradiation make this bonding agent curing, coating is set, as optical thin film.The Δ nd of optical thin film and the measurement result of twist angle are respectively 192nm and 64 degree.

Embodiment 19～23

Adopt method similarly to Example 18 to make the optical thin film of various parameters.The results are shown in table 2.

Embodiment 24

The polyester 5.00g that polyester 15.0g that embodiment 2 obtains and synthesis example 1 obtain is housed in the polymer reactor that stirring apparatus, nitrogen ingress pipe, liquid trap are housed, after in the nitrogen replacement reactor, stirred 1 hour in 250 ℃ of fusions.The glass transition temperature of resulting polyester composition is 70 ℃.In addition, the result of polarized light microscope observing shows that this polymkeric substance shows the cholesteric crystal phase more than glass transition temperature, even and be cooled to below the glass transition temperature, do not find transfer yet to crystallization phase, the cholesteric orientation is immobilized.

Secondly, prepare phenol/tetrachloroethane (60/40 weight ratio) mixed solvent solution of 8 weight % of this polymer blend.This solution is coated with method of spin coating having the on glass of polyimide film that rubbed, on hot plate in 55 ℃ of dryings 20 minutes., take out from the baking oven that cleans after 20 minutes in 190 ℃ of thermal treatments in the baking oven of cleaning, the natural air cooling obtains the optical thin film that the cholesteric orientation is immobilized.Resulting optical thin film shows that cholesteric is orientated distinctive selection irradiation, and reflected light is green, reflection left light.The result that the section of optical thin film is observed with TBM is that the thickness of liquid crystal layer part is 2.31 μ m.In addition, arriving the light and shade shape of stripes that is orientated from cholesteric with the glass substrate parallel observations, is 0.33 μ m from the visible screw pitch of its fringe number, and the spiral number of times is 7 times.

Embodiment 25

The polymer A 4.00g that polymkeric substance 16.00g that embodiment 7 uses and embodiment 8 obtain is dissolved in N,N-dimethylacetamide 80g, obtain solution.This solution method of spin coating, go up coating at the polyphenylene sulfide film of crossing through rayon cloth friction treatment (Dong Li company makes, ト レ リ Na), in baking oven in 55 ℃ of dryings remove desolvate after, in 230 ℃ of thermal treatments 10 minutes, form the hybrid orientation structure again.After the thermal treatment, take out natural cooling from baking oven, the hybrid orientation structure is as vitreousness be fixed (film 2).

Because film 2 forms on opaque and optically anisotropic polyphenylene sulfide film, so be difficult to directly use as optical thin film.Therefore; air interface side coating UV curing adhesive (East Asia Synesis Company manufacturing at film 2; UV-3400) about 5 μ m are thick; (description film company of Fuji makes the tri acetyl cellulose film of each homogeny film of optics of lamination 80 μ m thereon; Off ジ ッ Network T80SZ); by shining the UV of about 600mJ, this bonding agent is solidified.Then, peel off the polyphenylene sulfide film, liquid crystal layer is transferred on the tri acetyl cellulose membrane from tri acetyl cellulose membrane/adhesive phase/liquid crystal layer/polyphenylene sulfide film all-in-one-piece layered product.In addition, to the liquid crystal layer surface coated UV curing adhesive of peeling off polyphenylene sulfide film side (East Asia Synesis Company makes, and UV-3400) about 5 μ m are thick, in the oxygen barrier state down the UV light (high-pressure sodium lamp) of the about 600mJ of irradiation make this bonding agent curing, coating is set, as optical thin film.The result that obtains of the birefringent wavelength dispersion value D of this optical thin film is D=1.080.The results are shown in table 3.In addition, the KOBRA-21ADH that uses prince's instrumentation machines corporation to make is measuring wavelength 590nm, measures the interior visual angle interdependence that postpones of face of film, the results are shown in Fig. 4.

Embodiment 26

Adopt polyimide film as orientation substrate, except that as heat-treat condition be 230 ℃ 10 minutes, again in 190 ℃ 6 minutes, carry out similarly to Example 22.The results are shown in table 3 and Fig. 4.

Embodiment 27

(Sumitomo Chemical Co. Ltd. makes, and SRW-862AP) and the last coated side of the optical thin film of making according to embodiment 19 1 (Δ nd=136nm), carries out lamination with the adhesive phase of about 25 μ m, obtains layered product 1 at polaroid.At this moment, the axis of orientation of the absorption axes of polaroid and optical thin film 1 is disposed with 45 degree skews.The results verification that this layered product 1 usefulness ellipsograph carries out polarization analysis is, reaches 0.98 circular polarizing disk in the ellipticity of wavelength 550nm.

Embodiment 28

(Sumitomo Chemical Co. Ltd. makes at polaroid, SRW-862AP) and the last coated side of the optical thin film of making according to embodiment 20 2 (Δ nd=270nm), adhesive phase with about 25 μ m carries out lamination, make the last coated side of optical thin films 1 (Δ nd=136nm) again according to embodiment 19, adhesive phase with about 25 μ m carries out lamination, obtains layered product 2.At this moment, the axis of orientation of the absorption axes of polaroid and optical thin film 1 is disposed with 60 degree skews, and the axis of orientation in axis of orientation in the optical thin film 1 and the optical thin film 2 is offset 15 degree configurations again.The results verification that these layered product 2 usefulness ellipsographs carry out polarization analysis is, reaches 0.98 circular polarizing disk in the ellipticity of wavelength 550nm.

Embodiment 29

(Sumitomo Chemical Co. Ltd. makes, and SRW-862AP) and the last coated side of the optical thin film of making according to embodiment 22 3, carries out lamination with the adhesive phase of about 25 μ m, obtains layered product 3 at polaroid.At this moment, the last coated side axis of orientation in the absorption axes of polaroid and the optical thin film 3 is disposed with 45 degree skews.The results verification that these layered product 3 usefulness ellipsographs carry out polarization analysis is, reaches 0.10 in the ellipticity of wavelength 550nm, and in addition, ellipsoidal polarizing plate has because of the different ellipticity value of wavelength.

Embodiment 30

The glass substrate and being provided with that preparation is provided with the IT0 transparency electrode has formed the glass substrate of trickle concavo-convex aluminium reflection electrode.(daily output chemical company makes, and SE-7992), carries out friction treatment to form alignment film of polyimide respectively in the electrode side of 2 glass substrates.By the spacer film of 2.4 μ m, overlapping relatively the alignment films of 2 substrates.The direction of regulating substrate makes the frictional direction of 2 alignment films reach antiparallel.(Merck company makes, and ZLI-1695), forms liquid crystal layer to inject liquid crystal in the gap of substrate.Make Δ nd value like this and reach the unwrung ECB type liquid crystal pond of 150nm.The glass substrate side of IT0 transparency electrode is being set, is pasting the circular polarizing disk of embodiment 28 by the adhesive phase of about 25 μ m.On the reflection-type liquid-crystal display device of making, show that to black 6V applies voltage, carry out the evaluation of display characteristic from white demonstration 0V, though results verification whitely shows, blackly shows, and Neutral colour show and can show well.With analyzer (CM-3500d, Minolta company makes), measure the contrast of reflecting brightness, the result is that positive contrast is 22.In the present embodiment, under the state of netrual colour filtrator, experimentize,, can carry out good polychrome or panchromatic demonstration as in the liquid crystal pond, coloured filter being set.

Table 1

	Add monomer than (ratio)	ηinh (dL/g)	Tg (℃)	n e	n o	Δn	The D value	Δnd (nm)
									Embodiment 1	CCBA∶MHQ∶CT (10∶5∶5)	0.18	115	1.680	1.539	0.141	1.099	170
Embodiment 2	CCBA∶BHDC∶MHQ∶CT (5∶5∶5∶5)	0.25	104	1.658	1.535	0.123	1.085	150
									Embodiment 3	CCBA∶BHDC∶MHQ∶CT (4∶6∶5∶5)	0.27	100	1.651	1.532	0.119	1.076	135
Embodiment 4	CCBA∶BHDC∶MHQ∶tBuHQ∶CT (5∶5∶4∶1∶5)	0.23	110	1.656	1.534	0.122	1.080	159
									Embodiment 5	CCBA∶BHDC∶MHQ∶23DAN (5∶5∶5∶5)	0.20	112	1.688	1.541	0.147	1.095	188
Embodiment 6	CCBA∶BHDC∶MHQ∶12DAN (5∶5∶5∶5)	0.24	113	1.681	1.539	0.140	1.089	170
									Embodiment 7	PABA∶CCBA∶BHDC∶CT∶tBuCT (10∶5∶5∶9∶1)	0.15	105	1.657	1.535	0.122	1.078	137
Embodiment 8	CCBA∶C5∶MHQ∶CT (8∶2∶5∶5)	0.18	90	1.670	1.535	0.135	1.090	130
									Embodiment 9	PABA∶2FPABA∶CCBA∶BHDC∶CT (5∶5∶5∶5∶10)	0.23	100	1.636	1.531	0.105	1.068	169
Embodiment 10	PABA∶CCBA∶CT (10∶10∶10)	0.16	112	1.695	1.540	0.155	1.099	160
									Embodiment 11	PABA∶CCBA∶BHDC∶CT (8∶5∶5∶10)	0.23	104	1.656	1.534	0.122	1.076	138
Embodiment 12	PABA∶CCBA∶23DAN (8∶10∶10)	0.22	110	1.696	1.541	0.155	1.099	145
									Embodiment 13	PABA∶CCBA∶12DAN (8∶10∶10)	0.23	108	1.692	1.539	0.153	1.097	210
Embodiment 14	PABA∶CCBA∶tBuHQ∶CT (5∶10∶2∶8)	0.22	114	1.694	1.539	0.155	1.098	175
									Embodiment 15	PABA∶CCBA∶BHDC∶MHQ∶CT (5∶5∶5∶1∶9)	0.24	102	1.657	1.535	0.122	1.077	125
Embodiment 16	PABA∶CCBA∶CHDC∶tBuHq∶CT (8∶5∶5∶1∶9)	0.20	106	1.656	1.535	0.121	1.077	140
									Comparative example 1	TPA∶26NDCA∶MHQ∶CT (5∶5∶5∶5)	0.18	104	1.808	1.579	0.229	1.150	175

CCBA:4-(4-carboxyl ring ethyl) benzoic acid

BHDC:1,1 '-dicyclohexyl-4,4 '-dicarboxylic acid

TPA: terephthalic acid (TPA)

26NDCA:2, the 6-naphthalenedicarboxylic acid

C5: heptandioic acid

MHQ: methyl ammonia quinone diacetate esters

CT: catechol diacetate esters

TBuHQ: tertiary butylated hydroquinone diacetate esters

TBuCT: tert-butyl catechol diacetate esters

23DAN:2, the 3-diacetoxy naphthalene

12DAN:1, the 2-diacetoxy naphthalene

PABA:p-acetoxyl group benzoic acid

2FPABA:2-fluoro-4-acetoxyl group benzoic acid

CHDC:1, the 4-cyclohexane dicarboxylic acid

Table 2

	The ratio of liquid crystal polyester/polymer A (g/g)	Orientation substrate	Twist angle	Δnd (nm)	The D value
						Embodiment 18	19.80/0.20	Polyimide	64	192	1.076
Embodiment 19	20.00/0	PPS	0	136	1.076
						Embodiment 20	20.00/0	PEEK	0	270	1.076
Embodiment 21	19.80/0.20	PPS	200	600	1.076
						Embodiment 22	19.82/0.18	PPS	240	800	1.076
Embodiment 23	19.80/0.20	Polyimide	70	200	1.076

PPS: polyphenylene sulfide

PEEK: polyetheretherketone

Table 3

	Orientation substrate	Δnd(nm)	Δ nd value	The D value
					Embodiment 25	PPS	151	1.05	1.08
Embodiment 26	Polyimide	135	1.18	1.08

The possibility of utilizing on the industry

Optical thin film of the present invention, the immobilization of liquid crystal aligning is easy, can realize that little birefringence wavelength disperses, and industrial can be easily and cheap making, but the optical characteristics Correctly adjusts such as birefringence wavelength dispersion are to desirable value, desirable state of orientation is fixed, and forms uniform large tracts of land.

Claims (11)

1. optical thin film, it is made of the polyester that contains the structural unit that following general formula a and b represent:

-O-W-O- b

Among the formula b, W represents to be selected from the bivalent radical in the base of representing with following formula w, and substituent R b represents hydrogen atom, F, Cl, Br, CF ₃, phenyl, the alkyl of carbon number 1～5 or the alkoxy of carbon number 1～5, q is 1～4, in addition, the structural unit that formula b also can be represented by formula w different more than 2 kinds constitutes:

2. according to the described optical thin film of claim 1, it is characterized in that above-mentioned polyester is liquid crystal liquid crystal property.

3. according to the optical thin film described in claim 1 or 2, it is characterized in that above-mentioned polyester is by except that containing structural unit a and b, the polyester that also contains at least a kind of structural unit of representing with following formula c, d and e constitutes:

-O-Z-O- e

Among the formula c, X represents to be selected from the bivalent radical in the base of representing with following formula x, and substituent R c represents hydrogen atom, F, Cl, Br, CF ₃, the alkyl of carbon number 1～5 or the alkoxy of carbon number 1～5, r is 1～4, in addition, the structural unit that formula c also can be represented by formula x different more than 2 kinds constitutes, among the formula d, Y represents to be selected from the bivalent radical in the base of representing with following formula y, and substituent R d represents hydrogen atom, F, Cl, Br, CF ₃, the alkyl of carbon number 1～5 or the alkoxy of carbon number 1～5, s is 1～4, m is 2～10, in addition, the structural unit that formula d also can be represented by formula y different more than 2 kinds constitutes, among the formula e, Z represents to be selected from the bivalent radical in the base of representing with following formula z, and substituent R e represents hydrogen atom, F, Cl, Br, CF ₃, cyano group, the alkyl of carbon number 1～5 or the alkoxy of carbon number 1～5, t is 1～4, in addition, the structural unit that formula e also can be represented by formula z different more than 2 kinds constitutes,

4. according to claim 1 or 2 described optical thin films, it is characterized in that above-mentioned polyester is made by the liquid crystalline polyester that structural unit a1～45 mole %, b1～45 mole %, c10～50 mole %, d0～44 mole % and e0～44 mole % constitute.

5. according to claim 1 or 2 described optical thin films, it is characterized in that above-mentioned polyester is made by the liquid crystalline polyester that structural unit a1～50 mole %, b1～49 mole %, c0～50 mole %, d0～49 mole % and e1～49 mole % constitute.

6. according to claim 1 or 2 described optical thin films, it is characterized in that, when being D with respect to the birefringence value Δ n (450nm) that measures wavelength 450nm light with respect to the ratio of the birefringence value of the birefringence value Δ n (590nm) that measures wavelength 590nm light, D is in the scope of 1.00＜D＜1.12.

7. according to claim 1 or 2 described optical thin films, it is characterized in that, with homogeneous phase orientation, the axially evenly in addition immobilization of any state of orientation of orientation, hybrid orientation, twisted nematic orientation or cholesteric orientation of pole-face.

8. a liquid crystal display cells is characterized in that, has any one described optical thin film of at least 1 claim 1～7.

9. a circular polarizing disk is characterized in that, has any one described optical thin film of 1～7 of claim.

10. an ellipsoidal polarizing plate is characterized in that, has any one described optical thin film of 1～7 of claim.

11. a liquid crystal display cells is characterized in that, has claim 9 or 10 described circular polarizing disk or ellipsoidal polarizing plates.

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