JPH07278326A - Liquid oligomer polymer composition film, its production, complex phase defference plate and liquid crystal display device - Google Patents

Abstract

PURPOSE:To obtain the subject product capable of providing a liquid crystal display device of a wide scope angle, having an optical axis in parallel with the direction of a normal line, comprising a composition of a polymer of a specific liquid crystal oligomer and a low-molecular compound. CONSTITUTION:This product comprises (A) a polymer of a liquid crystal oligomer which is a linear or a cyclic liquid crystal oligomer composed of units of formula I and formula II (A is a group of formula III or formula IV; R1 and R2 each is H, phenyl or the like when A is a group of formula III and H or a 1-6C alkyl when A is a group of formula IV, (k) and (k') each is 2-10; (m) and (m') each is 0 or 1; Ar1 to Ar4 each is 1,4-phenylene, 1,4-cyclophenylene, etc.; L and L' each is CH2, O, etc.; R is a halogen, cyano, etc.; R' is H or a 1-5C alkyl), having 1-20 units of formula I and 1-20 units of formula II, 4-21 total of both the units of the formula I and formula II, has a positive refractive index aisotropy and shows a nematic phase or a smectic phase and (B) a low-molecular compound selected from a compound of formula V and a compound of formula VI (R5 and R6 each is H, a 1-20C alkyl, etc.; (m) and (n) each is 1 or 2; R7 is H or methyl; R8 is a 1-30C hydrocarbon).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an oriented liquid crystal oligomer polymer composition film useful as a member of a retardation film used for a liquid crystal display device, a method for producing the same, an oriented liquid crystal oligomer polymer composition film and a hydrophilic group. The present invention relates to a laminate with a material, a composite retardation film including the same and a uniaxially oriented retardation film, and a liquid crystal display device using the same.

[0002]

2. Description of the Related Art A retardation film is a polymer film having optical homogeneity and durability and having uniaxial orientation,
It is generally used as an optical compensation plate for improving the display quality of liquid crystal display elements. A super twist nematic (hereinafter sometimes referred to as STN) type liquid crystal display device using a retardation film has advantages such as light weight, thinness, and low cost, but has poor viewing angle characteristics and poor black and white level. Had the disadvantages such as. These disadvantages have been considerably improved by a method such as laminating two retardation films, but the viewing angle characteristics have not yet reached a satisfactory level.

The viewing angle characteristics of the liquid crystal display device are largely correlated not only with the angle dependency of the birefringence of the liquid crystal cell for display but also with the angle dependency of the retardation of the retardation film. It is known that the smaller the change in retardation angle, the better. For this purpose, it has been proposed to vertically align a liquid crystalline material and use a retardation film having a high refractive index in the direction normal to the film surface.

JP-A-2-73327 and JP-A-2-105111 disclose that in order to reduce the angle change of the background color of an ECB (voltage controlled birefringence index) type display cell that is homogeneously aligned when no voltage is applied. Although the in-plane refractive index is isotropic, a method using a birefringent layer having a refractive index in the thickness direction larger than the in-plane refractive index is disclosed.
As a material having such a refractive index anisotropy, a homeotropic (vertical) oriented compensating liquid crystal cell is exemplified.

Further, in JP-A-2-256023, by using a film having an optical axis in the direction normal to the film surface and a retardation film having a positive birefringence value, the angle change of retardation is changed. It is described that the retardation film can be obtained and the viewing angle characteristics are improved. As a film having an optical axis in the normal direction of the film, a photopolymerizable compound and a liquid crystal monomer are mixed, and while maintaining the alignment of the liquid crystal monomer in an electric field, the polymerization proceeds and the alignment in the normal direction is fixed. How to do is listed.

In Japanese Patent Laid-Open No. 4-16916, a birefringent layer having a refractive index in the thickness direction larger than an in-plane refractive index is used.
It is disclosed that the birefringent layer is composed of a vertically aligned polymer liquid crystal. Regarding the method of vertically aligning polymer liquid crystals, after heating to the liquid crystal temperature, applying an electric field or magnetic field in the thickness direction, and sandwiching it with two substrates whose surfaces are treated with a vertical aligning agent such as a silane compound. A method of vertically aligning at a liquid crystal temperature is disclosed, and it is shown that a retardation film excellent in viewing angle characteristics can be obtained by combining with a retardation film obtained by stretching a polymer. On the other hand, polyvinyl alcohol, which is a polymer having a hydroxyl group in the side chain, is used as a horizontal alignment film of liquid crystal in a liquid crystal display device, is applied on the substrate of a transparent electrode, and is rubbed to horizontally align liquid crystal molecules. It is known to cause.

[0007]

However, it is not known that the optical axis of a polymer laminated film obtained by laminating a liquid crystal oligomer polymer composition and a hydrophilic substrate is substantially parallel to the normal line direction. Further, regarding a composite retardation film of a polymer liquid crystal / polymer laminated film and a retardation film, in the conventional method, when a film having an optical axis in the normal direction of the film and a retardation film are combined, In order to have the optical axis in the normal direction, while maintaining the orientation of the liquid crystal monomer having a large orientation relaxation, photopolymerization, an external field such as an electric field or a magnetic field is required,
An operation of sandwiching between the two substrates which were made hydrophobic and peeling was required. For high molecular weight liquid crystals, the alignment method is complicated, and for low molecular weight liquid crystals, it is difficult to fix the alignment. As described above, the conventional method has a problem that an industrially advantageous manufacturing method has not been established. The present invention provides a novel oriented liquid crystal oligomer polymer composition film having an optical axis substantially parallel to the normal direction and an industrially advantageous method for producing the same, which is laminated with a transparent or semitransparent polymer film. Or by combining with a uniaxially oriented retardation film, a composite retardation plate having a wide viewing angle and a liquid crystal display device are provided.

[0008]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the inventors of the present invention have found that a liquid crystal oligomer having a positive refractive index anisotropy and exhibiting a nematic phase or a smectic phase has a low specific content. It was found that the alignment can be fixed by polymerizing after adding a molecular compound for homeotropic alignment, and an alignment liquid crystal having an optical axis almost parallel to the normal direction of the substrate surface on a hydrophilic substrate. It was possible to obtain an oligomer polymer composition film, and by combining the oriented liquid crystal oligomer polymer composition film with a retardation film having uniaxial orientation, excellent black and white level and good viewing angle characteristics were obtained. The present invention has been completed by finding that a liquid crystal display device can be obtained.

That is, the present invention comprises the following inventions. [1] A film composed of a polymer of a liquid crystal oligomer having a positive refractive index anisotropy and exhibiting a nematic phase or a smectic phase and a low molecular weight compound, the liquid crystal oligomer comprising the following repeating units (I) and (II). When the number of repeating units (I) and (II) in one molecule of the oligomer selected from linear or cyclic liquid crystal oligomers as main constituent units is N and N ', N and N'are independent of each other. Is an integer of 1 to 20, and 4 ≦ N + N ′ ≦ 21, the terminal group of the repeating unit (II) is polymerized, and the low-molecular compound has the following general formulas (V), (VI), ( VII)
And at least one selected from the group consisting of hard coat agents, and the composition is the liquid crystal oligomer 100.
The oriented liquid crystal oligomer polymer composition, wherein the total amount of the low molecular weight compound is 0.1 to 40 parts by weight with respect to parts by weight, and the optical axis of the film is substantially parallel to the normal direction of the film. the film.

[0010]

[Chemical 9]

[0011]

[Chemical 10] [Wherein A is a group represented by the following formula (III) or (IV), and in formula (III), -Si-O- is represented by formula (I).
Or the main chain of (II), and in the formula (IV), -C
—CH ₂ — is the backbone of formula (I) or (II),
The OO group is located on a side chain that is not R ₁ or R ₂ of the side chain. When A is formula (III) in formula (I) and A is formula (III) in formula (II), R ₁ and R ₂ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms or phenyl. It is a base. In formula (I), when A is formula (IV), and in formula (II), A is formula (I)
In the case of V), R ₁ and R ₂ independently represent hydrogen or 1 to 1 carbon atoms.
6 is an alkyl group.

[0012]

[Chemical 11]

[Chemical 12] k and k ′ independently represent an integer of 2 to 10, m and m ′ independently represent 0 or 1, and Ar ₁ , Ar ₂ , Ar ₃ and Ar ₄ independently represent a 1,4-phenylene group, 1,4-cyclohexylene group, pyridine-2,5-diyl group, pyrimidine-2,5-diyl group, and L and L'are independently -C.
_{H 2 -O -, - O-} CH 2 -, - COO -, - OCO
_{-, - CH 2 CH 2 -} , - CH = N -, - N = CH- or

[Chemical 13] Is a divalent group represented by, p and p ′ are independently 0 or 1, R is a halogen, a cyano group, an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, R'is hydrogen or an alkyl group having 1 to 5 carbon atoms. ]

[0013]

[Chemical 14] (In the formula, Ar ₁ and Ar ₂ are independently a 1,4-phenylene group,
1,4-cyclohexylene group, pyridine-2,5-diyl group, pyrimidine-2,5-diyl group, and R ₄ is
Halogen, cyano group, methacryloyl group, acryloyl group, alkyl group having 1 to 20 carbon atoms or 1 to 20 carbon atoms
Is an alkoxy group, and L is —CH ₂ —O—, —O—C.
_{H 2 -, - COO -,} - OCO -, - CH 2 -CH
_{2 -, - CH = N -} , - N = CH-, a divalent group represented 1,4-phenylene group or formula (V) in,, p is 0 or 1, R ₃ the number of carbon atoms It is an alkyl group having 3 to 30 or an alkoxy group having 3 to 30 carbon atoms. )

[Chemical 15] (In the formula, R ₅ and R ₆ are independently hydrogen and a carbon number of 1
To an alkyl group having 20 to 20 or an alkoxy group having 1 to 20 carbon atoms, and m and n each independently represent 1 or 2. )

[0014]

[Chemical 16] (In the formula, R ₇ is hydrogen or a methyl group, and R ₈ is a hydrocarbon group having 1 to 30 carbon atoms.)

[2] The repeating unit (I) described in [1] above.
After a mixture of a linear or cyclic liquid crystal oligomer consisting of and (II) and a low molecular weight compound is formed on a film, heat treatment is performed to make the optical axis substantially parallel to the film normal direction, and then the end of the repeating unit (II). The method for producing an oriented liquid crystal oligomer polymer composition film as described in [1], wherein the group is polymerized.

[3] A laminate of the oriented liquid crystal oligomer polymer composition film as described in [1] above and a transparent or semitransparent substrate having a hydrophilic surface.

[4] The substrate is a glass plate, a hydrophilic polymer film or a polymer laminated film in which a hydrophilic polymer and a transparent or semitransparent polymer film are laminated [3] The laminate described.

[5] The base material is a uniaxially oriented retardation film made of a thermoplastic polymer having an optical axis in the film plane and having a positive refractive index anisotropy. The refractive index of the laminate of the combined composition film and the substrate is represented by the following formula (1) n _x > n _z > n _y (1) (where n _x and n _y are in-plane refractive indices of the laminate, respectively). Of the laminated body, and _nz represents a refractive index in the thickness direction of the laminated body.) [3].

[6] A uniaxially oriented retardation film made of a thermoplastic polymer having an optical axis in the film plane and having positive refractive index anisotropy, and the laminate as described in [3]. A composite retardation plate formed by stacking layers, wherein the composite retardation plate has a refractive index represented by the following formula (1) n _x > n _z > n _y (1) (where n _x and n _y are laminated composite phase difference plates, respectively). A composite retardation plate, which represents the maximum value and the minimum value of the in-plane refractive index of the film, and _nz represents the refractive index in the thickness direction of the laminated composite retardation film.

[7] A polarizing film, an oriented liquid crystal oligomer polymer composition film as described in [1] or [3],
A polarizing film laminated composite retardation film, which is obtained by laminating the laminate according to [4] or [5] or the composite retardation plate according to [6] with an adhesive or an adhesive. [8] A liquid crystal cell sandwiched between substrates having electrodes, which has a positive dielectric anisotropy, and is composed of a liquid crystal layer which is substantially horizontal when no voltage is applied and has a helical axis twisted and aligned in a direction perpendicular to the substrate, Between the polarizing film placed on the outside,
The oriented liquid crystal oligomer polymer composition film according to [1], the laminate according to any one of [3] to [5],
At least one selected from the composite retardation plate described in [6] and the polarization film laminated composite retardation film described in [7] is used.

[9] A homogeneous alignment liquid crystal cell in which a nematic liquid crystal having a positive dielectric constant anisotropy is substantially horizontally aligned with the major axis of the substrate horizontally when no voltage is applied, and a polarizing film arranged outside thereof. And a liquid crystal using at least one selected from the oriented liquid crystal oligomer polymer composition film described in [1] and the laminate described in any one of [3] to [5]. Display device.

The present invention will be described in detail below. The liquid crystal oligomer comprising the repeating units (I) and (II) used in the present invention is a side chain type liquid crystal oligomer having a positive refractive index anisotropy in a liquid crystal state and having a nematic phase or a smectic phase. The side chain type liquid crystal oligomer has a skeletal chain of poly-1
Examples thereof include alkyl acrylates and polysiloxanes, and linear or cyclic ones can be used. Among the poly-1-alkyl acrylic acid esters, polymethacrylic acid ester or polyacrylic acid ester is preferable,
More preferred is polymethacrylic acid ester. Among these, a polysiloxane-based side chain type liquid crystal oligomer is preferable, and a cyclic polysiloxane side chain type liquid crystal oligomer is more preferable, from the viewpoint of easily obtaining vertical alignment. As the group that imparts liquid crystallinity (hereinafter sometimes referred to as mesogen group), a group bonded to the main chain via a bent chain (hereinafter sometimes referred to as spacer) can be generally used.

The side chain type liquid crystal oligomer is required to be in a liquid crystal state at a use temperature, that is, from room temperature to about 60 ° C. The transition temperature from the liquid crystal phase to the isotropic phase (hereinafter sometimes referred to as the transition temperature of the liquid crystal phase / isotropic phase) becomes 200 ° C. or less due to drying or orientation treatment during lamination with the substrate. As described above, it is preferable to select the length of the spacer, the kind of the mesogenic group, and the degree of polymerization so that the temperature is preferably 170 ° C. or lower, and more preferably 150 ° C. or lower.

The side chain type liquid crystal oligomer used in the present invention is
It is necessary to orient to have anisotropy in refractive index, but the number of repeating units is important as a factor that determines the ease of operation. When the number of repeating units is large, the viscosity is high, and the liquid crystal transition temperature is high, so that high temperature and long time are required for the alignment, and when the number of repeating units is small, the alignment is relaxed at room temperature, which is not preferable. The numbers of repeating units, n and n ', are each independently an integer from 1 to 20 and are selected such that the sum of n and n'is 4 to 21. From the viewpoint of alignment of the liquid crystal oligomer and fixing of alignment after polymerization, the ratio of n and n ′ is in the range of 1: 5 to 5: 1, and more preferably 1: 3 to 3: 1. n and n '
The ratio of can be controlled when synthesizing these liquid crystal oligomers as described later.

The side chain type liquid crystal oligomer has a main chain and a mesogenic group.
The liquid crystal transition temperature and orientation are also dependent on the spacer that connects
To be affected. With a short spacer, the orientation of the mesogenic groups is
Poor and mesogenic group orientation with long spacers
Since relaxation afterwards is likely to occur, as a spacer,
Alkylene group or alkylene having 2 to 10 carbon atoms
An oxy group is preferred. Especially from the viewpoint of high orientation, it has 2 carbon atoms.
To alkylene groups or alkyleneoxy groups
preferable. In addition, due to the ease of synthesis, alkyleneoxy
More preferred are groups. Specifically, as a preferable group,-(C
H₂)₂-,-(CH₂)₃-,-(CH₂)_Four-,-
(CH₂)_Five-,-(CH₂)₆-,-(CH₂)₃−
O-,-(CH₂)_Four-O-,-(CH₂)_Five-O-,
-(CH ₂)₆-O- is exemplified.

The oriented liquid crystal oligomer polymer film of the present invention
In terms of film, it is industrially advantageous that the anisotropy of the refractive index is large.
Is. For this purpose, the mesogenic group has a large refractive index anisotropy.
Kina groups are preferred. Structures that provide such mesogenic groups
Is a repeating unit (I) or A in the formula (II)
r₁, Ar₂, Ar₃, Ar_FourBut each independently 1,
4-phenylene group, 1,4-cyclohexylene group, pyri
Gin-2,5-diyl group or pyrimidine-2,5-di
Examples thereof include yl-based ones. Also, Ar₁And Ar₂To
Or Ar₃And Ar_FourThe divalent group L that binds to is -CH₂
-O-, -O-CH ₂-, -COO-, -OCO-,-
CH₂-CH₂-, -CH = N-, -N = CH- or
Is

[0026]

[Chemical 17] Or a group in which Ar ₁ and Ar ₂ are directly bonded or a group in which Ar ₃ and Ar ₄ are directly bonded. More preferably, Ar ₁ , Ar ₂ , Ar ₃ and Ar ₄ are each independently a 1,4-phenylene group, pyridine-2,
5-diyl group, pyrimidine-2,5-diyl group,
More preferably, it is a 1,4-phenylene group. Further, the bonding groups L and L ′ are independently -CH ₂ -CH ₂ -,-.
A COO- group and a -OCO- group are preferable, and a -COO- group is more preferable.

The R group in the repeating unit (I) affects the dielectric anisotropy and orientation of the mesogenic group, so that from the viewpoint of obtaining a liquid crystal oligomer film having a high refractive index anisotropy, a halogen, a cyano group or a carbon group is used. An alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms is selected. A cyano group, an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms is preferable, and a cyano group is more preferable.

The terminal group in the repeating unit (II) is a group that fixes the orientation of the liquid crystal oligomer by polymerization. The polymerization group is -OCO-C (R ') = CH 2 (R' represents hydrogen or an alkyl group having 1 to 5 carbon atoms), acrylate groups, methacrylate groups. The method of polymerizing these groups is not particularly limited, but photopolymerization or thermal polymerization with a radical initiator is exemplified, and photopolymerization is preferable from the viewpoint of ease of operation and efficiency of fixing orientation. Known photopolymerization initiators can be used.

The non-polymerizable mesogenic group used for the linear or cyclic liquid crystal oligomer having the repeating unit represented by the repeating unit (I) is shown below.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

[Table 3]

[0033]

[Table 4]

Among these mesogen groups, the numbers 1 to 6, 31 to 36, 61 to 66, and 181 having a cyano group are included.
The groups 186 and 211 to 216 are preferable, and the numbers 31 to 36 are more preferable. It is preferable that these mesogen groups are bonded to a polysiloxane-based main chain because they exhibit high orientation, and more preferably those bonded to a cyclic siloxane.

The polymerizable mesogen group used for the linear or cyclic liquid crystal oligomer having the repeating unit (II) is exemplified below.

[0036]

[Table 5]

[0037]

[Table 6]

[0038]

[Table 7]

Among these polymerizable mesogen groups, numbers 247 to 252 and 259 to 2 having a methacrylate group.
64, 271-276, 319-324, 331-33
The group of 6 is preferable, and more preferably the numbers 259 to 264.
It is the basis of It is preferable that these mesogen groups are bonded to a linear or cyclic polysiloxane-based main chain because they exhibit good properties, and it is more preferable that they are bonded to a cyclic polysiloxane.

As a method for synthesizing these liquid crystal oligomers, Japanese Patent Publication No. 63-41400 and Japanese Patent Publication No. 63-4775.
The method described in Japanese Patent Laid-Open No. 9-149549 or Japanese Patent Laid-Open No. 2-149544 can be used. Examples thereof include a method of adding a mesogenic group of the side chain to a polysiloxane chain and a method of polymerizing an acrylic acid ester or a methacrylic acid ester having a mesogenic group via a flexible spacer group. When a mesogenic group is added to the polysiloxane chain, the repeating unit (I)
Or (II) has the same structure as the side chain mesogenic group,
It can be obtained by reacting a reaction raw material having a ω-alkenyloxy group having an unsaturated double bond at the terminal which forms an alkyleneoxy group as a spacer with a polysiloxane under a platinum catalyst. During this reaction, the bond ratio of the two kinds of mesogen groups can be controlled by the reaction raw material charging ratio corresponding to the non-polymerizable mesogen group and the polymerizable mesogen group. Similarly, in the case where the main chain is an acrylic ester type or an α-alkyl-acrylic acid type, when the two kinds of monomers having the corresponding mesogenic groups are copolymerized, the charging ratio of the monomers is controlled so that a polymerizable mesogenic group is formed. The proportion of non-polymerizable mesogenic groups can be controlled. The liquid crystal oligomer thus obtained preferably has a nematic phase or a smectic phase. Further, those exhibiting a smectic phase exhibit more excellent optical anisotropy and are therefore more preferred.

As described above, in the present invention, by selecting the length of the spacer of the liquid crystal oligomer, the kind of the mesogenic group, the degree of polymerization, etc., a liquid crystal oligomer having a preferable vertical alignment property can be obtained. Furthermore, by mixing a liquid crystal oligomer with a low molecular weight compound that lowers the transition temperature of the liquid crystal oligomer from the liquid crystal phase to the isotropic phase (hereinafter sometimes referred to as the transition temperature), the properties such as alignment, viscosity, and liquid crystal transition temperature can be improved. Can be changed to a more preferable range.

In the present invention, as the low molecular weight compound mixed with the liquid crystal oligomer, the above-mentioned general formulas (V) and (V
It is at least one compound selected from the group consisting of I), (VII) and a hard coat agent.

In the low molecular weight compound represented by the general formula (V), R ₃ represents an alkyl group having 3 to 30 carbon atoms or an alkoxy group having 3 to 30 carbon atoms, specifically, propyl, butyl and hexyl. , Octyl, dodecyl, octadecyl, docosyl, eicosyl, propoxy, butoxy,
Examples include groups such as hexyloxy, octyloxy, dodecyloxy, octadecyloxy, docosanoxy, eicosyloxy. R ₄ is a halogen, a cyano group, a methacroyl group, an acryloyl group, or a carbon number of 1 to 20.
Represents an alkyl group or an alkoxy group having 1 to 20 carbon atoms. Specific examples of the alkyl group and the alkoxy group include methyl, ethyl, propyl, butyl, hexyl, octyl, dodecyl, octadecyl, methoxy, ethoxy, propoxy, butoxy, hexyloxy, octyloxy, dodecyloxy, octadecyloxy. Groups such as.

The low molecular weight compound represented by the general formula (V) is preferably a compound represented by the following general formula (VIII).

[Chemical 18] As the low molecular weight compound represented by the general formula (V), cyanobiphenyl compounds are particularly preferable. Specifically, 4-cyano-
Examples include 4'-hexylbiphenyl, 4-cyano-4'-octylbiphenyl, 4-cyano-4'-octyloxybiphenyl and the like.

In the low molecular weight compound represented by the general formula (VI) (hereinafter sometimes referred to as benzophenone derivative), R ₅ and R ₆ are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms or a carbon atom. It represents an alkoxy group of the formula 1 to 20. Specific examples of the alkyl group and the alkoxy group include methyl, ethyl, propyl, butyl,
Examples include groups such as hexyl, octyl, dodecyl, octadecyl, methoxy, ethoxy, propoxy, butoxy, hexyloxy, octyloxy, dodecyloxy, octadecyloxy. As the low molecular weight compound represented by the general formula (VI), specifically, 4-methylbenzophenone, 4-ethylbenzophenone, 4-butylbenzophenone, 4-octylbenzophenone, 4-methoxybenzophenone, 4-ethoxybenzophenone, 4 -Butoxybenzophenone, 4-octyloxybenzophenone, 4,4'-dimethoxybenzophenone, 4,
Examples thereof include 4'-diethoxybenzophenone, 4,4'-dibutoxybenzophenone and 4,4'-dioctyloxybenzophenone, with 4-methoxybenzophenone being preferred. In the low molecular weight compound represented by the general formula (VII) (hereinafter sometimes referred to as an acrylic ester derivative), R ₇ is hydrogen or a methyl group, and R _7
8 is a hydrocarbon group having 1 to 30 carbon atoms. Specific examples of the hydrocarbon group represented by R ₈ include methyl, ethyl, propyl, butyl, hexyl, octyl, dodecyl, octadecyl, docosyl and eicosyl. As the low molecular weight compound represented by the general formula (VII), specifically, methyl acrylate, ethyl acrylate, butyl acrylate, octyl acrylate, dodecyl acrylate, octadecyl acrylate, methyl methacrylate, ethyl methacrylate, Butyl acrylate, octyl methacrylate,
Dodecyl methacrylate, octadecyl methacrylate and the like can be mentioned. Of these, octadecyl methacrylate is preferred.

Examples of the hard coat agent include known photo-curable resin-based acrylic oligomer-based, urethane acrylate-based, epoxy acrylate-based, polyester acrylate-based, and thermosetting resin-based acrylic-silicone-based materials. Specifically, a list of plastic coating technologies [Industrial Technology Service Center, 183
Pp. 191]. Among these, from the viewpoint of affinity with the liquid crystal oligomer polymer and film-forming property, a photocurable resin-based acrylic oligomer system is preferable.

The amount of the low molecular weight compound used in the present invention is 0.
It is in the range of 1 to 40 parts by weight. The mixing amount is preferably 0.5 to 25 parts by weight, more preferably 1 to 15 parts by weight. If it is less than 0.1 parts by weight, the effect of addition does not appear,
Further, if it exceeds 40 parts by weight, the physical properties of the oriented liquid crystal oligomer polymer composition film are adversely affected, which is not preferable. The mixing method is not particularly limited. A mixing method in a solution state, an isotropic phase state, or the like can be mentioned, but a mixing method in a solution state is preferable because a film can be easily formed. The transition temperature between the crystal phase or glass phase and the liquid crystal phase of these liquid crystal oligomer compositions is not particularly limited, and the transition temperature below room temperature can be used.

Next, a method for producing an oriented liquid crystal oligomer polymer composition film will be described. As a method for producing an oriented liquid crystal oligomer polymer composition film having an optical axis substantially parallel to the film normal direction of the present invention, a liquid crystal oligomer composition film is formed on a hydrophilic substrate, and an alignment treatment is performed. . First, there is no limitation on the method for forming the liquid crystal oligomer composition film, but examples thereof include a method of applying the liquid crystal oligomer composition in a solution state and a method of applying it in an isotropic phase state, and preferably the solution state is applied. There is a method. As a coating method, a normal roll coating method,
The gravure coating method, the bar coating method, the spin coating method, the spray coating method, the printing method, and the depping method are exemplified.

The alignment treatment is carried out by heat-treating the liquid crystal oligomer composition film, and the liquid crystal phase is converted to an isotropic phase at a temperature above the transition temperature from the crystal phase or the glass phase to the liquid crystal phase (hereinafter sometimes referred to as Tg). Transition temperature (hereinafter T
Sometimes referred to as i. ) The following temperatures are adopted. The heat treatment temperature (hereinafter sometimes referred to as Tt) is preferably (Tg + 30 ° C.) ≦ Tt <Ti, and more preferably (Tg + 40 ° C.) ≦ Tt <Ti. The heat treatment time is not particularly limited,
If it is too short, the vertical alignment property is not sufficient, and if it is too long, it is not industrially preferable. Therefore, it is preferably 0.05 minutes or more and 20 hours or less, more preferably 0.1 minutes or more and 1 hour or less. By the above heat treatment, the mesogenic groups of the liquid crystal oligomer are oriented in a direction substantially perpendicular to the film surface, and the film has an optical axis in the direction normal to the film surface.

The liquid crystal oligomer composition film is oriented so that it has an optical axis substantially parallel to the normal to the film surface, and then the liquid crystal oligomer is polymerized. The polymerization method is not limited, but photopolymerization, radiation polymerization such as γ-ray, and thermal polymerization are exemplified because it is necessary to polymerize while maintaining the orientation. A known polymerization initiator can be used in photopolymerization or thermal polymerization. Among these polymerization methods, photopolymerization and thermal polymerization are preferable because of the ease of the steps, and further, photopolymerization is more preferable because the retention of orientation is good.

The thickness of the oriented liquid crystal oligomer polymer composition film is preferably 0.1 to 20 μm, more preferably 0.5 to 10 μm, and further preferably 1
~ 7 μm. When the thickness is less than 0.1 μm, the expression of optical properties becomes small, and when it exceeds 20 μm, the orientation is difficult, which is not preferable. The obtained oriented liquid crystal oligomer polymer composition film can be used as it is, but it is preferable to use it by laminating it on a substrate.

As the substrate having a hydrophilic surface, a glass plate alone or a glass plate surface used in a liquid crystal cell can be used, and a hydrophilic material containing a hydroxyl group, a carboxylate ion group or a sulfonate ion group can be used. Polymers can also be used. Further, a polymer base material having a hydrophilic polymer layer on its surface can also be used. Examples of the polymer having a hydroxyl group among the hydrophilic polymers include polyvinyl alcohol, polyethylene vinyl alcohol copolymer, pullulan obtained by microbial fermentation from starch syrup, and polymers selected from natural polysaccharides such as dextrin. . Polyvinyl alcohol is preferable from the viewpoint of solubility and ease of giving vertical alignment. Examples of the polymer having a carboxylate ion include polyacrylic acid, sodium polyacrylate, polymethacrylic acid, sodium polyalginate, polycarboxymethyl cellulose soda salt and the like, and sodium polyalginate, polycarboxymethyl cellulose soda salt, polyacrylic Acids are preferred. Moreover, polystyrene sulfonic acid is illustrated as a polymer containing a sulfonate ion. Among these hydrophilic polymers, polyvinyl alcohol, sodium polyalginate, polycarboxymethyl cellulose sodium salt, polyacrylic acid, pullulan and polystyrene sulfonic acid are preferable, and polyvinyl alcohol and sodium polyalginate are more preferable.

The hydrophilic substrate used in the laminate of the oriented liquid crystal oligomer polymer composition film and the hydrophilic substrate, which is another embodiment of the present invention, is the above-mentioned glass plate, hydroxyl group or carboxylate ion group. Similarly, a polymer having a sulfonate ion can be used, and a transparent or semitransparent polymer film having these hydrophilic polymers on the surface can also be used. The shape of the hydrophilic substrate used is a thin plate or a film when used in a liquid crystal display device, and a film is preferable as a polymer material. In the laminate of the oriented liquid crystal oligomer polymer composition film of the present invention and the hydrophilic substrate, the hydrophilic substrate is for aligning the optical axis of the liquid crystal oligomer polymer composition film substantially parallel to the normal direction. It is valid. However, since the rubbing-treated polyvinyl alcohol acts as a horizontal alignment film as described above, the rubbing treatment in the hydrophilic polymer layer adversely affects the alignment of the optical axis, which is not preferable.

As a transparent or translucent polymer film coated with the hydrophilic polymer used in the present invention, polycarbonate, polysulfone, polyarylate, polyether sulfone, cellulose diacetate, cellulose triacetate,
Examples thereof include polystyrene, ethylene vinyl alcohol copolymer, polyethylene terephthalate, polyethylene naphthalate, and the like, with preference given to polycarbonate, polysulfone, cellulose triacetate, polyethylene terephthalate, and polystyrene.

In the laminate of the oriented liquid crystal oligomer polymer composition film of the present invention and the hydrophilic substrate, the optical axis thereof can be made substantially parallel to the normal line direction of the film as in the case of the liquid crystal oligomer composition film. The liquid crystal oligomer composition film and the hydrophilic substrate are heat-treated under various heat treatment conditions. At that time, a polymer that does not cause changes in optical properties or shape in the temperature range is preferable, and a thermoplastic engineering polymer having a high glass transition temperature or a polymer having a plasticizer added has a high flowing temperature. Is mentioned. The glass transition temperature of the polymer is not particularly limited,
It is preferably 100 ° C or higher, more preferably 110 ° C or higher. Cellulose triacetate, polycarbonate, polysulfone, polyether sulfone and polyethylene terephthalate are preferable as the polymer satisfying this condition, and cellulose triacetate, polycarbonate, polysulfone and polyether sulfone are more preferable. Then, the liquid crystal oligomer composition film is polymerized in the same manner to fix the orientation.

Next, with respect to the method for producing a laminate of the oriented liquid crystal oligomer polymer composition film of the present invention and the hydrophilic polymer, an example of a substrate having a hydrophilic polymer coated on the surface of the polymer film will be given. explain. First, using a transparent or translucent polymer film such as polycarbonate, polysulfone, polyarylate, polyethersulfone, cellulose diacetate, cellulose triacetate, polyethylene terephthalate, polyethylene naphthalate as a substrate, Film is formed on the surface.

The method for forming the hydrophilic polymer is not particularly limited, but for example, after the polymer is dissolved in a solvent in which the hydrophilic polymer can be dissolved and the base material is less dissolved or swelled, roll coating is performed. Method, gravure coating method, bar coating method, spin coating method, spray coating method, printing method,
Examples thereof include a method of applying a known method such as a depping method, and a method of melting the polymer and then applying a known method such as a roll coating method, a gravure coating method, a bar coating method, a spray coating method, and a depping method. It From the viewpoint of easy production among these coating methods, a roll coating method, a gravure coating method, a bar coating method from a polymer solution,
It is preferable to form a film by a spin coating method, a spray coating method, a depping method or the like. Polymer films such as polycarbonate, polysulfone, polyarylate, and polyethersulfone have low surface tension and may be repelled by a hydrophilic polymer solution.Therefore, known surface modification such as plasma treatment, corona treatment, or ultraviolet irradiation is performed. The hydrophilic polymer may be deposited after increasing the surface tension of these polymer films by a technique.

The thickness of the transparent or semitransparent polymer film used is not particularly limited, but is preferably 1 μm or more and 500 μm or less, more preferably 10 μm or more and 300 μm or less, and further preferably 40 μm or more and 200 μm or less.

The thickness of the obtained hydrophilic polymer is not particularly limited, but is not less than 0.1 μm and not more than 500 μm,
It is preferably 0.5 μm or more and 100 μm or less, more preferably 1 μm or more and 50 μm or less. The solvent used is not particularly limited as long as it dissolves the hydrophilic polymer, but water is preferably used.

Then, the liquid crystal oligomer composition is formed on the polymer film on which the hydrophilic polymer is formed. The film forming method is not particularly limited, and for example, a film can be formed in the same manner as a liquid crystal oligomer composition film, and the liquid crystal oligomer composition is dissolved in a solvent that does not dissolve or swell the base material or the hydrophilic polymer, and then roll coating is performed. Method, gravure coating method, bar coating method, spin coating method, spray coating method, printing method, depping method, or the like, or heating the liquid crystal oligomer composition to a temperature above the solid phase / liquid crystal phase transition temperature to form a liquid crystal oligomer. After the viscosity is reduced, a method of applying by a known method such as a roll coating method, a gravure coating method, a bar coating method, a spray coating method or a depping method is exemplified. From the viewpoint of easy production among these coating methods, it is preferable to form a film from the liquid crystal oligomer composition solution by a roll coating method, a gravure coating method, a bar coating method, a spin coating method, a spray coating method, a depping method, or the like. .

The thickness of the obtained oriented liquid crystal oligomer polymer composition layer is preferably 0.1 μm or more and 20 μm or less, more preferably 0.5 μm or more and 10 μm or less, and further preferably 1 μm or more and 7 μm or less. 0.1 μ
When the thickness is less than m, the expression of optical properties becomes small, and 2
If it is thicker than 0 μm, the orientation is difficult, which is not preferable.

As described above, in order to obtain a high degree of vertical alignment of the liquid crystal oligomer, the liquid crystal oligomer composition / polymer laminated film is heat-treated in the same manner as in the case of the liquid crystal oligomer composition film described above at the same temperature and treatment time. . But,
Especially in the case where the glass transition temperature of the base material used or the base material to which the additive is added is above the flow temperature of the base material, there is a problem in the production process such as the deformation of the base material or the hydrophilic polymer. The glass transition temperature or flow temperature of is preferably below. By this treatment, the liquid crystal oligomer on the polymer substrate is almost vertically aligned. Also, the rate of temperature rise in heat treatment,
There is no particular limitation on the cooling rate.

The method for producing the transparent or translucent polymer film of the present invention includes solvent casting, extrusion molding,
A molding method such as a press molding method may be used.

Even when a glass plate or a hydrophilic polymer film is used as the substrate, a laminate of the liquid crystal oligomer polymer composition and the substrate can be obtained in the same manner.

The oriented liquid crystal oligomer polymer composition film or the laminate of the oriented liquid crystal oligomer polymer composition film and the hydrophilic substrate of the present invention has an optical axis substantially parallel to the film normal direction, By using simultaneously a uniaxially oriented retardation film made of a thermoplastic polymer having an optical axis and having a positive refractive index anisotropy,
It can be a composite retardation plate or a composite retardation film. Hereinafter, the composite retardation plate or the composite retardation film is generically referred to as a composite retardation plate.

Examples of the thermoplastic polymer having positive refractive index anisotropy used in the composite retardation plate of the present invention include polycarbonate, polysulfone, polyarylate, polyether sulfone, cellulose diacetate, cellulose triacetate, polyvinyl alcohol, Examples thereof include polyethylene vinyl alcohol copolymer and polyethylene terephthalate. The thermoplastic polymer is uniaxially oriented and used as a retardation film. The laminate of the oriented liquid crystal oligomer polymer composition / hydrophilic substrate and the uniaxially oriented retardation film may be laminated by sticking them together with a pressure sensitive adhesive or an adhesive,
You may separate and use each.

As a method for producing a film (hereinafter sometimes referred to as a raw film) used as a raw material for a retardation film composed of these thermoplastic polymers, there are solvent casting method, extrusion molding method, press molding method and the like. A molding method may be used. Examples of the stretching method for making the original film a uniaxially oriented retardation film having an optical axis in the film plane include a tenter stretching method, a roll stretching method, and a roll compression stretching method. In order to obtain a uniform retardation film, it is preferable to stretch the film formed by the solvent casting method by the tenter stretching method.

In the liquid crystal display device of the present invention, an oriented liquid crystal oligomer polymer composition film, a laminate of the liquid crystal oligomer polymer composition film and a hydrophilic substrate, and a laminated composite retardation containing the oriented liquid crystal oligomer polymer composition film. The position on which the plate is placed is not particularly limited, and may be anywhere between the two polarizing plates of the liquid crystal display. For example, between the polarizing plate and the liquid crystal cell for display, between the polarizing plate and the protective film of the polarizing plate, between the retardation film and the polarizing plate, between the retardation film and the liquid crystal cell for display, the protective film of the retardation film and the retardation film. For example, the period between is illustrated.

Further, the oriented liquid crystal oligomer polymer composition film, the laminate of the liquid crystal oligomer polymer composition film and the hydrophilic substrate, and the laminated composite retardation plate containing the oriented liquid crystal oligomer polymer composition film are used as a polarizing plate. It may be used by pasting with an adhesive or an adhesive.

[0070]

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. The glass transition point of the obtained liquid crystal oligomer and the transition temperature between the liquid crystal phase and the isotropic phase were evaluated by a polarization microscope observation and a differential scanning calorimeter (DSC). The liquid crystal oligomer was scanned at a scanning rate of 10 ° C./min, and the transition temperature was evaluated from the data of the second and subsequent times.
Regarding Tg, the peak of the first derivative of the endothermic curve at the time of temperature rise was regarded as Tg, and for Ti, the endothermic peak which is considered to be due to the liquid crystal phase / isotropic phase transition was regarded as Ti.

In order to confirm that the obtained oriented liquid crystal oligomer polymer composition film / substrate laminate has an optical axis substantially in the direction of the normal to the film, when the substrate does not have birefringence, it is measured under crossed Nicols. It was confirmed that the laminated film was almost completely extinguished when placed horizontally, and then it was confirmed that it was tilted about an arbitrary axis and the retardation increased as the tilt angle increased.

In order to evaluate the laminated composite retardation plate or film of the present invention, in-plane birefringence is first evaluated. In a polarizing microscope equipped with a tilt stage, the laminated film is arranged horizontally, and the retardation (hereinafter abbreviated as R (0)) is determined by a Senarmont birefringence measurement method using a Senarmont compensator. Next, in the evaluation of birefringence in the thickness direction, θ ° with the optical axis direction in the horizontal plane as the tilt axis
Retardation (hereinafter R
(Abbreviated as (θ)).

The viewing angle of the laminated composite retardation plate or film is defined as the viewing angle when θ (R) is R (θ) = 1.10 × R (0).

Example 1 7 of polyvinyl alcohol (Poval 117 manufactured by Kuraray Co., Ltd.) was formed on a cellulose acetate film having a thickness of 80 μm.
% Aqueous solution, and dried in hot air at 100 ° C. The thickness of the obtained polyvinyl alcohol was 2 μm. Four
-(Allyl-oxy) -benzoic acid-4'-cyanophenyl ester and 4- (allyloxy) -benzoic acid- (4 '
-Metacroyloxy-phenyl) ester was reacted with pentamethylcyclopentasiloxane at a mixing ratio of 1: 1 in the same manner as in the method described in JP-B-63-41400 to give a non-polymerizable mesogenic group and a polymerizable mesogenic group. A cyclic pentasiloxane liquid crystal oligomer having a side chain of about 1: 1 was obtained. The elemental analysis value of this liquid crystal oligomer is C = 61.7% by weight,
H = 5.3 wt% and N = 2.0 wt%, and the content of the cyclic pentasiloxane liquid crystal oligomer determined from the gel permeation chromatogram area percentage was 69%. Further, the side chain mesogen addition rate determined by integrating the peaks of the ¹ H-NMR spectrum was about 80%. The Tg of the obtained liquid crystal oligomer was 18.
It was 7 degreeC and Ti was 117.5 degreeC.

The obtained cyclic pentasiloxane liquid crystal oligomer was dissolved in methylene chloride to 10 wt%, and 4-cyano-4′-hexylbiphenyl was added thereto in an amount of 3 parts by weight based on 100 parts by weight of the liquid crystal oligomer, and further photopolymerized. As a starting material, Irgacure 907 (manufactured by Ciba-Geigy) was mixed in an amount of 2 parts by weight based on 100 parts by weight of the liquid crystal oligomer. The liquid crystal oligomer composition solution was applied onto the cellulose triacetate film coated with polyvinyl alcohol using a bar coat. After coating, it was dried at room temperature. The resulting liquid crystal oligomer composition thin film was cloudy.

The obtained liquid crystal oligomer composition / polyvinyl alcohol / 3 cellulose acetate laminated film was treated at 70 ° C.
After heating for 5 minutes in a constant temperature bath heated to 1, the resulting liquid crystal oligomer composition laminated film was irradiated with a high pressure mercury lamp on the irradiation surface at a light intensity of 500 mW / cm ² .

The obtained oriented liquid crystal oligomer polymer composition / polymer laminate film was extinguished under crossed Nicols, and the retardation was 5.3 nm, which is thought to be attributable to cellulose triacetate. When it was tilted, the retardation increased. The retardation when tilted at 60 degrees was 77 nm. At this time, the haze of the film was measured by a haze meter (direct reading haze computer HGM-2DP manufactured by Suga Test Instruments Co., Ltd.) and found to be 3.2%. In addition, a film contact type film thickness meter (Alpha Step AS-200 manufactured by Tencor Co., Ltd.)
The thickness of the oriented liquid crystal oligomer polymer composition layer was measured by 3 and found to be 3 μm.

Next, a uniaxially oriented retardation film made of polycarbonate having an optical axis in the plane of the film and having a positive refractive index anisotropy [trade name: Sumikalite SE
F-400426, R (0) = 380 nm, viewing angle 39
]] And an oriented liquid crystal oligomer polymer composition / polymer laminated film were laminated, the viewing angle was 60 ° or more, and a composite retardation film with a wider viewing angle was obtained as compared with the case of using the polycarbonate retardation film alone. Was given.
Further, when this composite retardation film is arranged between the upper polarizing plate of the STN type liquid crystal display device and the liquid crystal cell, a black and white display is obtained, and a good viewing angle characteristic is exhibited. Further, the composite retardation film, the upper polarizing plate of the STN type liquid crystal display device, and the butyl acrylate pressure-sensitive adhesive, which are laminated together, can be used in the same manner and exhibit good visual field characteristics.

Example 2 4-cyano-4'-hexylbiphenyl of Example 1 was replaced with 4
A laminated film of an oriented liquid crystal oligomer polymer composition film and a polymer was obtained in the same manner as in Example 1 except that 8 parts by weight of -cyano-4'-octyloxybiphenyl was used. The obtained oriented liquid crystal oligomer polymer composition / polymer laminated film was quenched under crossed Nicols and had a retardation of 3
The thickness was 5.3 nm, which is thought to be attributable to cellulose acetate, but the retardation increased when the laminated film was tilted from the horizontal plane. The retardation when tilted at 60 degrees was 50 nm. At this time, the haze of the film was measured with a haze meter (direct reading haze computer HGM-2DP manufactured by Suga Test Instruments Co., Ltd.) to be 1.4%.
Met. Further, the thickness of the oriented liquid crystal oligomer polymer composition layer was measured with a film needle type film thickness meter (Alpha Step AS-200 manufactured by Tencor Co., Ltd.), and it was 3 μm.

When the polycarbonate retardation film used in Example 1 and the oriented liquid crystal oligomer polymer composition / polymer laminated film were laminated, the viewing angle was 60 ° or more, which is larger than that of the polycarbonate retardation film alone. A composite retardation film having a wider viewing angle was obtained.
Further, when this composite retardation film is arranged between the upper polarizing plate of the STN type liquid crystal display device and the liquid crystal cell, a black and white display is obtained, and a good viewing angle characteristic is exhibited.

Example 3 7% of polyvinyl alcohol (Poval 117 manufactured by Kuraray Co., Ltd.) was formed on a cellulose acetate film having a thickness of 80 μm.
% Aqueous solution, and dried in hot air at 100 ° C. The thickness of the obtained polyvinyl alcohol was 2 μm. The cyclic pentasiloxane liquid crystal oligomer obtained in Example 1 was dissolved in methylene chloride to a concentration of 10 wt%, and 4-
Methoxybenzophenone was mixed in an amount of 10 parts by weight with respect to 100 parts by weight of the liquid crystal oligomer. The liquid crystal oligomer composition solution was applied onto the cellulose triacetate film coated with polyvinyl alcohol using a bar coat. The resulting oriented liquid crystal oligomer composition thin film was cloudy. The obtained liquid crystal oligomer composition / polyvinyl alcohol / 3 cellulose acetate laminated film was heated in a constant temperature bath heated to 55 ° C. for 5 minutes, and then a high-pressure mercury lamp was irradiated on the irradiated surface at a light intensity of 500 mW / cm ² to achieve alignment. The liquid crystal oligomer composition laminated film was irradiated.

The obtained oriented liquid crystal oligomer polymer composition / polymer laminate film was extinguished under crossed Nicols, and the retardation was 5.3 nm, which is thought to be attributable to cellulose triacetate. When it was tilted, the retardation increased. The retardation when tilted at 60 degrees was 55 nm. At this time, the haze of the film was measured by a haze meter (direct reading haze computer HGM-2DP manufactured by Suga Test Instruments Co., Ltd.) and found to be 2.2%. In addition, a film contact type film thickness meter (Alpha Step AS-200 manufactured by Tencor Co., Ltd.)
The thickness of the oriented liquid crystal oligomer polymer composition layer was measured by 3 and found to be 3 μm.

When the polycarbonate retardation film used in Example 1 and the oriented liquid crystal oligomer polymer composition / polymer laminate film were laminated, the viewing angle was 60 ° or more, which was larger than that of the polycarbonate retardation film alone. A composite retardation film having a wider viewing angle was obtained.

Further, this composite retardation film was treated with STN.
When it is arranged between the upper polarizing plate and the liquid crystal cell of the type liquid crystal display device, a black and white display is obtained and a good viewing angle characteristic is exhibited. Example 4 Example 1 except that the 4-cyano-4′-hexylbiphenyl of Example 1 was replaced with octadecyl methacrylate 3 wt%.
A laminated film of an oriented liquid crystal oligomer polymer composition film and a polymer was obtained in the same manner as in. The obtained oriented liquid crystal oligomer polymer composition / polymer laminated film was extinguished under crossed nicols, and the retardation was 5.3 nm, which is thought to be due to cellulose triacetate, but when the laminated film was tilted from the horizontal plane, The retardation has increased. The retardation when tilted at 60 degrees was 70.0. At this time, the haze of the film is measured by a haze meter (direct reading haze computer HGM manufactured by Suga Test Instruments Co., Ltd.
It was 1.8 when measured by (-2DP). Further, the thickness of the oriented liquid crystal oligomer polymer composition layer was measured by a film needle type film thickness meter (Alpha Step AS-200 manufactured by Dencor Co., Ltd.), and it was 3 μm.

When the polycarbonate retardation film used in Example 1 and the oriented liquid crystal oligomer polymer composition / polymer laminated film were laminated, the viewing angle was 60 ° or more, which was larger than that of the polycarbonate retardation film alone. A composite retardation film having a wider viewing angle was obtained.
Further, when this composite retardation film is arranged between the upper polarizing plate of the STN type liquid crystal display device and the liquid crystal cell, a black and white display is obtained, and a good viewing angle characteristic is exhibited.

Example 5 Example 4 was repeated except that 4-cyano-4′-hexylbiphenyl of Example 1 was replaced by 10 wt% of hard coat agent trade name Lipoxy SP-1509 (Showa Highpolymer Co., Ltd.). A laminated film of the oriented liquid crystal oligomer polymer composition film and the polymer was obtained. The obtained oriented liquid crystal oligomer polymer composition / polymer laminate film was extinguished under crossed nicols, and the retardation was 5.3 nm, which is thought to be due to cellulose triacetate, but the laminate film was tilted from the horizontal plane. And the retardation became bigger. The retardation when tilted at 50 ° was 82.5. At this time, the haze of the film is measured by a haze meter (direct reading haze computer HGM manufactured by Suga Test Instruments Co., Ltd.
It was 6.5 when measured by (-2DP). The thickness of the oriented liquid crystal oligomer polymer composition layer was measured with a film probe type film thickness meter (Alpha Step AS-200 manufactured by Dencor Co., Ltd.), and it was 3 μm. When the polycarbonate retardation film used in Example 1 and the oriented liquid crystal oligomer polymer composition / polymer laminate film were laminated, the viewing angle was 60 ° or more, which was wider than that of the polycarbonate retardation film alone. A corner composite retardation film was obtained. Further, when this composite retardation film is arranged between the upper polarizing plate of the STN type liquid crystal display device and the liquid crystal cell, a black and white display is obtained, and a good viewing angle characteristic is exhibited.

Example 6 A laminate of an oriented liquid crystal oligomer polymer film and a hydrophilic substrate was obtained in the same manner as in Example 1 except that the polycarbonate retardation film was not laminated. When this laminated body is arranged between the polarizing plate and the liquid crystal cell of the homogeneous alignment ECB type liquid crystal display device, good viewing angle characteristics are exhibited.

Comparative Example 1 A laminated film of a liquid crystal oligomer polymer composition and a polymer was obtained in the same manner as in Example 1 except that after the liquid crystal oligomer composition was applied, no heat treatment was applied. The obtained laminated film was cloudy. Observation of the laminated film obtained under crossed Nicols revealed that it was cloudy and that the liquid crystal oligomer polymer composition was not vertically aligned.

[0089]

Effects of the Invention By using an oriented liquid crystal oligomer polymer composition film whose optical axis is substantially parallel to the normal direction, and by laminating the oriented liquid crystal oligomer polymer composition film with a transparent or semitransparent polymer film. Or in combination with a uniaxially oriented retardation film, a composite retardation plate with a wide viewing angle can be obtained. In addition, these are STN type liquid crystal display devices or homogeneous alignment ECBs.
By applying the liquid crystal display device to a liquid crystal display device, the display characteristics of the liquid crystal display device, especially the viewing angle characteristics can be remarkably improved.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G02B 5/30 G02F 1/133 500 1/1335 510

Claims (9)

[Claims] 1. A film comprising a polymer of a liquid crystal oligomer having a positive refractive index anisotropy and exhibiting a nematic phase or a smectic phase and a low molecular weight compound, wherein the liquid crystal oligomer has the following repeating units (I) and (II). ) Is a linear or cyclic liquid crystal oligomer having a main constitutional unit, and when the number of repeating units (I) and (II) in one molecule of the oligomer is N and N ′, respectively, N and N ′ are They are each independently an integer of 1 to 20 and 4 ≦ N + N ′ ≦
21, the terminal group of the repeating unit (II) is polymerized, and the low molecular weight compound has the following general formulas (V), (VI),
(VII) and at least one selected from the group consisting of hard coat agents, and the composition is such that the total amount of the low molecular weight compound is 0.
1 to 40 parts by weight, and the optical axis of the film is substantially parallel to the normal direction of the film, an oriented liquid crystal oligomer polymer composition film. [Chemical 1] [Chemical 2] [Wherein A is a group represented by the following formula (III) or (IV), and in formula (III), -Si-O- is represented by formula (I).
Or the main chain of (II), and in the formula (IV), -C
—CH ₂ — is the backbone of formula (I) or (II),
The OO group is located on a side chain that is not R ₁ or R ₂ of the side chain. When A is formula (III) in formula (I) and A is formula (III) in formula (II), R ₁ and R ₂ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms or phenyl. It is a base. In formula (I), when A is formula (IV), and in formula (II), A is formula (I)
In the case of V), R ₁ and R ₂ independently represent hydrogen or 1 to 1 carbon atoms.
6 is an alkyl group. [Chemical 3] [Chemical 4] k and k ′ independently represent an integer of 2 to 10, m and m ′ independently represent 0 or 1, and Ar ₁ , Ar ₂ , Ar ₃ and Ar ₄ independently represent a 1,4-phenylene group, 1,4-cyclohexylene group, pyridine-2,5-diyl group, pyrimidine-2,5-diyl group, and L and L'are independently -C.
_{H 2 -O -, - O-} CH 2 -, - COO -, - OCO
_{-, - CH 2 -CH 2 -} , - CH = N -, - N = CH-
Or [Chemical 5] Is a divalent group represented by, p and p ′ are independently 0 or 1, R is a halogen, a cyano group, an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, R'is hydrogen or an alkyl group having 1 to 5 carbon atoms. ] [Chemical 6] (In the formula, Ar ₁ and Ar ₂ are independently a 1,4-phenylene group, a 1,4-cyclohexylene group, and a pyridine-2,5-
A diyl group, a pyrimidine-2,5-diyl group, R ₄
Is a halogen, a cyano group, a methacryloyl group, an acryloyl group, an alkyl group having 1 to 20 carbon atoms or 1 to
20 is an alkoxy group, L is —CH ₂ —O—, —O
_{-CH 2 -, - COO -,} - OCO -, - CH 2 -CH
_2- , -CH = N-, -N = CH-, 1,4-phenylene group, or a divalent group represented by the formula (V), p is 0 or 1, and R ₃ is a carbon number. It is an alkyl group having 3 to 30 or an alkoxy group having 3 to 30 carbon atoms. ) [Chemical 7] (In the formula, R ₅ and R ₆ are independently hydrogen and a carbon number of 1
To an alkyl group having 20 to 20 or an alkoxy group having 1 to 20 carbon atoms, and m and n each independently represent 1 or 2. ) [Chemical 8] (In the formula, R ₇ is hydrogen or a methyl group, and R ₈ is a hydrocarbon group having 1 to 30 carbon atoms.) 2. Repeating units (I) and (I) according to claim 1.
After a mixture of a linear or cyclic liquid crystal oligomer of I) and a low molecular weight compound was formed on a film, heat treatment was performed to make the optical axis parallel to the normal direction of the film, and then the terminal group of the repeating unit (II) was added. Polymerizing, characterized in that
A method for producing the oriented liquid crystal oligomer polymer composition film described. 3. A laminate comprising the oriented liquid crystal oligomer polymer composition film according to claim 1 and a transparent or semitransparent substrate having a hydrophilic surface. 4. The glass substrate, the hydrophilic polymer film, or a polymer laminated film in which a hydrophilic polymer and a transparent or semitransparent polymer film are laminated, as the base material. Stack of. 5. A uniaxially oriented retardation film comprising a thermoplastic polymer, wherein the substrate has an optical axis in the plane of the film and has a positive refractive index anisotropy, and an oriented liquid crystal oligomer polymer. The refractive index of the laminate of the composition film and the substrate is represented by the following formula (1) n _x > n _z > _ny (1) (where n _x and n _y are the in-plane refractive indices of the laminate, respectively). It represents the maximum value and the minimum value, and _nz represents the refractive index in the thickness direction of the laminated body.) The laminated body according to claim 3. 6. A uniaxially oriented retardation film made of a thermoplastic polymer having an optical axis in the film plane and having positive refractive index anisotropy, and the laminate according to claim 3 are laminated. And a refractive index of the composite retardation plate is represented by the following formula (1) n _x > n _z > _ny (1) (where n _x and n _y are laminated composite retardation films, respectively). Of the in-plane refractive index, and _nz represents the refractive index in the thickness direction of the laminated composite retardation film.). 7. A polarizing film, an oriented liquid crystal oligomer polymer composition film according to claim 1, a laminate according to claim 3, 4 or 5 or a composite retardation plate according to claim 6, and an adhesive or A composite retardation film laminated with a polarizing film, which is laminated with an adhesive. 8. A liquid crystal cell comprising a liquid crystal layer sandwiched between substrates having electrodes, which has a positive dielectric anisotropy, and which is twisted and aligned substantially horizontally when a voltage is not applied and with a spiral axis perpendicular to the substrate. And between the polarizing film arranged on the outside,
An oriented liquid crystal oligomer polymer composition film according to claim 1, a laminate according to any one of claims 3 to 5, a composite retardation plate according to claim 6, and a polarizing film laminating composite position according to claim 7. A liquid crystal display device comprising at least one selected from retardation films. 9. A homogeneous alignment liquid crystal cell, in which a nematic liquid crystal having a positive dielectric anisotropy is sandwiched between substrates having electrodes and the major axis of which is aligned substantially horizontally with respect to the substrate when no voltage is applied, and is arranged outside thereof. At least one selected from the oriented liquid crystal oligomer polymer composition film according to claim 1 and the laminate according to any one of claims 3 to 5 is used between the polarizing film and the polarizing film. Display device.