JP2003048998A - Liquid crystal alignment film forming substrate and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal alignment film forming substrate excellent in heat resistance, solvent resistance, dimensional stability and excellent transparency, and a liquid crystal display element using the same. SOLUTION: A repeating unit (a) of a cyclic olefin having an alkoxysilyl group or a hydrolysis / condensation residue thereof and a repeating unit (b) of another cyclic olefin, and if necessary,-(CH ₂ -CHR ⁷⁾ A) a cyclic olefin-based copolymer containing a repeating unit (c) represented by-, wherein the number average molecular weight in terms of polystyrene is 1
A liquid crystal alignment film forming substrate comprising a crosslinked product obtained by crosslinking a cyclic olefin copolymer having a molecular weight of from 000 to 1,000,000 with a siloxane bond, and a liquid crystal display device using the substrate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a liquid crystal alignment film forming substrate and a liquid crystal display device. More specifically, the present invention relates to a liquid crystal alignment film forming substrate having good heat resistance, solvent resistance, dimensional stability, and excellent transparency, and a liquid crystal display device using the same.

[0002]

2. Description of the Related Art Conventionally, as a liquid crystal display element, a liquid crystal alignment film made of polyamic acid, polyimide or the like is formed on the surface of a substrate provided with a transparent conductive film to form a liquid crystal display element substrate, and two of them are opposed to each other. A nematic liquid crystal layer having a positive dielectric anisotropy is formed in the gap to form a cell having a sandwich structure, and the long axis of liquid crystal molecules is continuous from one substrate to the other substrate. So-called TN type (Twist)
An TN liquid crystal display device having an ed Nematic liquid crystal cell is known. Recently, STN (Super Twisted) has higher contrast and less viewing angle dependency than a TN type liquid crystal display element.
Nematic) type liquid crystal display elements and vertical alignment type liquid crystal display elements have been developed. This STN type liquid crystal display element uses a nematic type liquid crystal blended with a chiral agent which is an optically active substance as a liquid crystal, and the long axis of the liquid crystal molecules is twisted continuously between substrates over 180 degrees or more. , Which utilizes the resulting birefringence effect. Further, in the vertical alignment type liquid crystal display element, for example, a liquid crystal having a negative dielectric anisotropy of liquid crystal molecules is vertically aligned, and the liquid crystal molecules are tilted and horizontally operated by applying a voltage. Substrates in these liquid crystal display devices are required to have heat resistance for firing during the formation of an alignment film, as well as high transparency and good dimensional stability. Therefore, a glass substrate is usually used as a substrate for a liquid crystal display element.

In recent years, however, liquid crystal display devices have come to be used in mobile phones, mobile tools, PDAs (personal digital assistants), etc., and there is a demand for weight reduction in order to make them easy to carry. for that reason,
In recent years, plastic substrates have been used in place of glass substrates for liquid crystal display elements mounted on these devices in order to reduce the weight and reduce damage to the display element portion when dropped. This plastic substrate is usually PES
Although (polyether sulfone) and the like are used, since the glass transition temperature is as low as about 200 ° C., it is difficult to burn at a high temperature when forming an alignment film. Furthermore, the liquid crystal display device substrate is required to have no warpage in order to eliminate display quality and unevenness.
Since it is deformed by heat, it has a drawback that the firing temperature is limited.

Further, the following hydrides and addition polymers of ring-opening polymers have been proposed as materials for optical parts such as plastic substrate materials. (1) Hydrogenation product of ring-opening polymer (1-1) Hydrogenation product of ring-opening copolymer of tetracyclododecene compound (JP-A-60-26024 and JP-3050196) (1-2) ) Hydrogenation products of ring-opening copolymers of norbornene-based or tetracyclododecene-based compounds containing ester groups (JP-A-1-132625, JP-A-1-13226)
No. 26) (2) Addition polymer (2-1) Copolymer of ethylene and norbornene compound or tetracyclododecene compound [JP-A-61-2
92601, Makromol. Chem. Ma
cromol. Symp. Vol. 47,83 (199
1)] (2-2) Addition Polymer of Norbornene, Addition Copolymer of Norbornene and Alkyl-Substituted Norbornene (MetC
on97, June 4-5, 1997 B.I. L. Goo
dall et al., JP-A-4-63807, JP-A-8-
No. 198919) (2-3) Addition polymer of carboxylic acid ester of norbornene, addition copolymer of norbornene and carboxylic acid ester of norbornene, addition polymer of carboxylic acid of norbornene [Macromolecule, Vol. 29,
2755 (1996), Macromol. Rapi
d. Commun. Vol. 19, 251 (199
8), and International Patent Publication WO96 / 37526]

However, the above (1-1) and (1
Regarding the hydride of the ring-opening copolymer of -2), even if the same monomer is used, the ring-opening copolymer has a glass transition temperature relatively lower than that of the addition polymer and a polymer having a high glass transition temperature is used. Hard to get. Further, the ring-opening copolymer is
Difficult to completely hydrogenate, the hydride will contain traces of unsaturated bonds in the polymer, resulting in
It may be colored at the time of forming into a thin film, a film or a sheet at a high temperature of 250 ° C. or higher, which is not always sufficient in terms of heat resistance. The copolymer of (2-1) ethylene and a norbornene compound or a tetracyclododecene compound has a distribution in the ethylene chain,
If the ethylene chain is as long as possible, it will be crystallized and often insufficient in terms of optical transparency, and since it does not contain a polar group, it will be insufficient in terms of adhesion and adhesion.

On the other hand, the addition polymer (2-2) has a high glass transition temperature and high heat resistance, but is insufficient in terms of solvent resistance. Further, the addition polymer of norbornene carboxylic acid ester (2-3), the addition copolymer of norbornene and carboxylic acid ester of norbornene, and the addition polymer of norbornene carboxylic acid contain many polar groups,
Although it is excellent in terms of adhesiveness and adhesion, it is insufficient in terms of moisture absorption resistance and lacks in dimensional stability.

As a result of intensive studies, the inventors of the present invention have excellent heat resistance, solvent resistance, dimensional stability and transparency by using a cyclic olefin copolymer having a specific structure and a crosslinked product thereof. It was found that a liquid crystal alignment film forming substrate for forming an excellent liquid crystal display element can be obtained, and the present invention has been completed.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid crystal alignment film forming substrate having good heat resistance, solvent resistance, dimensional stability and excellent transparency, and a liquid crystal display device using the same. is there.

[0009]

The present invention is a liquid crystal alignment film-formed substrate comprising an electrode formed on a substrate and a liquid crystal alignment film formed thereon, wherein the substrate is represented by the following general formula (1):
Which is a cyclic olefin-based copolymer containing the repeating unit (a) shown in (1) and the repeating unit (b) shown in the following general formula (2), and has a polystyrene reduced number average molecular weight of 10,000.
The present invention relates to a liquid crystal alignment film-forming substrate comprising a crosslinked product in which a cyclic olefin-based copolymer having a molecular weight of 1,000,000 is crosslinked with a siloxane bond. The present invention also relates to a liquid crystal display device using the above-mentioned substrate for forming a liquid crystal alignment film.

[0010]

[Chemical 3]

[In the formula (1), A ^{1 to} A ⁴ are each independently a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or-(CR ¹ R ² ) _f Si (OR ³ ) _{g ^{R 4 (3-g),}} - (CR 1 R 2) f Si (R 3 R 4) OSi (OR 3) g R 4
_{(3-g), - (} CR 1 R 2) f C (O) O (CH 2) h Si (OR 3) g
R ⁴ _(3-g) represents an alkoxysilyl group, an aryloxysilyl group or a hydrolysis / condensation residue thereof, wherein at least one of A ^{1 to} A ⁴ is an alkoxysilyl group, an aryloxysilyl group or These hydrolysis / condensation residues are shown. here,
R ¹ and R ² are each independently a hydrogen atom or a carbon number 1
To 20 hydrocarbon groups, R ³ represents an alkyl group, an alkenyl group, an aryl group, and a cycloalkyl group having 1 to 10 carbon atoms, and R ⁴ represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms. Represents a group, f and h are integers of 0 to 5,
g represents an integer of 1 to 3. Further, Y is -CH ₂ - indicates a or -O-, m is 0 or 1. ]

[0012]

[Chemical 4]

[In the formula (2), B ¹ , B ² , B ³ and B ⁴ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, an alkenyl group, a cycloalkyl group or a halogen atom. Atom, halogenated hydrocarbon group, or-(C
H ₂ ) _j X represents a polar group. Where X is -C
(O) OR ^5, a ^{-OC (O) R 6, R} 5, R 6 is C 1 -C
To 20 alkyl groups, alkenyl groups, aryl groups, cycloalkyl groups and halogen substituents thereof, j is 0 to
Indicates an integer of 5. In addition, B ^{1 to} B ⁴ are B ¹ and B ² or B
Also included are an alkylidene group formed by ³ and B ⁴ , a cycloalkylene group and a cycloalkenylene group formed by B ¹ and B ² , B ¹ and B ³ or B ² and B ⁴ . n represents an integer of 0 to 2. ]

Further, the cyclic olefin copolymer may contain the repeating unit (c) represented by the general formula (3). - (CH ₂ -CHR ⁷⁾ - in · · · (3) [Equation (3), R ⁷ is a hydrogen atom or an aryl group, an alkyl-substituted Ari - indicating group, a trialkylsilyl group. ]

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The liquid crystal alignment film forming substrate of the present invention is
A cyclic olefin-based copolymer comprising the repeating unit (a) represented by the general formula (1) and the repeating unit (b), having a polystyrene-equivalent number average molecular weight of 10,000 to
It is a molded product in which a cyclic olefin copolymer of 1,000,000 is crosslinked with a siloxane bond. Repeating unit (a) used in the cyclic olefin-based copolymer of the present invention
Is a cyclic olefin represented by the following general formula (1) ′ (hereinafter,
It may be formed by addition polymerization of "a specific cyclic olefin (1)".

[0016]

[Chemical 5]

[In the formula (1) ', A ^{1 to} A ⁴ , Y, and m
Is the same as shown in the above formula (1). Specific examples of such a specific cyclic olefin (1) include 5-trimethoxysilyl-2-norbornene, 5-trimethoxysilyl-7-oxa-2-norbornene and 5-dimethoxy-chlorosilyl-2-norbornene. , 5-dimethoxy-chlorosilyl-7-oxa-2-norbornene, 5
-Methoxy-chloro-methylsilyl-2-norbornene, 5-dimethoxy-chlorosilyl-2-norbornene, 5-methoxy-hydrido-methylsilyl-2-norbornene, 5-dimethoxy-hydridosilyl-2-norbornene, 5-methoxydimethylsilyl- 2-norbornene, 5-triethoxysilyl-2-norbornene, 5
-Triethoxysilyl-7-oxa-2-norbornene, 5-methyl-dimethoxysilyl-2-norbornene, 5-methyl-dimethoxysilyl-7-oxa-2-
Norbornene, 5-diethoxy-chlorosilyl-2-norbornene, 5-ethoxy-chloro-methylsilyl-2
-Norbornene, 5-diethoxy-hydridosilyl-2
-Norbornene, 5-ethoxydimethylsilyl-2-norbornene, 5-ethoxydiethylsilyl-2-norbornene, 5-propoxydimethylsilyl-2-norbornene, 5-triphenoxysilyl-2-norbornene,
5-diphenoxymethylsilyl-2-norbornene, 5
-Trimethoxysilylmethyl-2-norbornene, 5-
(2-Trimethoxysilyl) ethyl-2-norbornene, 5- (2-dimethoxy-chlorosilyl) ethyl-2
-Norbornene, 5- (1-trimethoxysilyl) ethyl-2-norbornene, 5- (2-trimethoxysilyl) propyl-2-norbornene, 5- (1-trimethoxysilyl) propyl-2-norbornene, 5- Triethoxysilylethyl-2-norbornene, 5-dimethoxymethylsilylmethyl-2-norbornene, 5-trimethoxypropylsilyl-2-norbornene, 5-trimethoxysiloxydimethylsilyl-2-norbornene 5-
Triethoxysiloxydimethylsilyl-2-norbornene 5-methyldimethoxysiloxydimethylsilyl-2-
Norbornene 5-norbornene-2-carboxylic acid trimethoxysilylpropyl, 5-norbornene-2-carboxylic acid triethoxysilylpropyl, 7-oxa-5-norbornene-2-carboxylic acid triethoxysilylpropyl, 5-norbornene-2- Examples thereof include carboxylic acid dimethoxy and methylsilylpropyl. The compounds represented by the general formula (1) ′ that form the repeating unit (a) can be used alone or in combination of two or more.

The proportion of the repeating unit (a) in the cyclic olefin copolymer is 0.2 to 30 mol%, preferably 0.5 to 20 mol%, and more preferably 1.0 to 10 mol%. . When the proportion of the repeating unit (a) in the cyclic olefin-based copolymer is less than 0.2 mol%, it becomes difficult to form a crosslinked product. On the other hand, if the proportion exceeds 30 mol%, the moisture absorption resistance and the dimensional stability deteriorate.

The repeating unit (b) represented by the general formula (2) is a cyclic olefin represented by the following general formula (2) '(hereinafter referred to as "specific cyclic olefin (2)").
Can be formed by addition polymerization of

[0020]

[Chemical 6]

[In the formula (2) ', B ^{1 to} B ⁴ and n are the same as in the general formula (2). ] Specific examples of such "specific cyclic olefin (2)" include 2-norbornene, 5-methyl-2-norbornene, and 5-ethyl-2-.
Norbornene, 5-propyl-2-norbornene, 5-
Butyl-2-norbornene, 5-pentyl-2-norbornene, 5-hexyl-2-norbornene, 5-heptyl-2-norbornene, 5-octyl-2-norbornene, 5-decyl-2-norbornene, 5-dodecyl- Two
-Norbornene, 5,6-dimethyl-2-norbornene, 5-methyl-5-ethyl-2-norbornene, 5-
Phenyl-2-norbornene, 5-vinyl-2-norbornene, 5-allyl-2-norbornene, 5-isopropylidene-2-norbornene, 5-ethylidene-2-norbornene, 5-cyclohexyl-2-norbornene,
5-cyclohexenyl-2-norbornene, 5-indenyl-2-norbornene, 5,6-indane-2-norbornene, 5-fluoro-2-norbornene, 5-chloro-2-norbornene, 5-norbornene-2-carboxylic Methyl ester, ethyl 5-norbornene-2-carboxylate,
Butyl 5-norbornene-2-carboxylate, Methyl 2-methyl-5-norbornene-2-carboxylate, Ethyl 2-methyl-5-norbornene-2-carboxylate, 2-Methyl-5-norbornene-2-carboxylic acid Propyl, 2
-Methyl-5-norbornene-2-carboxylate butyl,
Trifluoroethyl 2-methyl-5-norbornene-2-carboxylate, Dimethyl 5-norbornene-2,3-dicarboxylate Diethyl 5-norbornene-2,3-dicarboxylate, 3-Tricyclo [4.3.0.1] ^2,5 ] decene,
3,7-Tricyclo [4.3.0.1 ^2,5 ] decadiene (dicyclopentadiene) 3-tetracyclo [4.4.
0.1 ^2,5 . 1 ^7,10 ] dodecene, 8-methyl-3-tetracyclo [4.4.0.1 ^2,5 . 1, ^{7, 10} ] dodecene, 8
-Methyl-8-carboxymethyl, 3-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecene, 8-methyl-8-carboxyethyl-3-tetracyclo [4.4.
0.1 ^2,5 . 1 ^7,10 ] dodecene, and the like. The compound represented by the general formula (2) ′ which forms the repeating unit (b) can be used alone or in combination of two or more kinds. Incidentally, dicyclopentadiene, 5-vinyl-2-norbornene, 5-allyl-
The polymer having an ethylenic double bond in the side chain of the polymer obtained by addition polymerization such as 2-norbornene can be further hydrogenated to improve heat resistance, oxidation resistance and deterioration resistance.

The proportion of the repeating unit (b) in the cyclic olefin copolymer of the present invention is 70 to 70% of all repeating units.
99.8 mol%, preferably 80-99.5 mol%,
More preferably, it is 90 to 99 mol%, and if the ratio is less than 70 mol%, the glass transition temperature may decrease, while if it exceeds 99.8 mol%, crosslinking becomes difficult.

The cyclic olefin copolymer may further contain the repeating unit (c) represented by the general formula (3). The repeating unit (c) represented by the general formula (3) is formed by copolymerizing an α-olefin (hereinafter, referred to as a “specific α-olefin”) represented by the following general formula (3) ′. You can

CH ₂ = CH (R ⁷ ) ... (3) '[In the formula (3)', R ⁷ is the same as the formula (3). ]

Specific examples of such a specific α-olefin include ethylene, styrene, p-methylstyrene,
Examples include o-methylstyrene, trimethylsilylethylene, triethylsilylethylene, and the like. These specific α-olefins may be used alone or in combination of two or more.

The proportion of the cyclic olefin copolymer as the repeating unit (c) is 0 to 40 mol% in all repeating units,
It is preferably 0 to 20 mol%. If the proportion of the repeating unit (c) exceeds 40 mol%, the glass transition temperature of the cyclic olefin-based copolymer will be low and the heat resistance will be low.

The cyclic olefin-based copolymer of the present invention comprises "specific cyclic olefin (1)" and "specific cyclic olefin (2)", and if necessary, "specific α-olefin".
By addition-copolymerizing the cycloolefin-based copolymer of the present invention.

As the polymerization catalyst, the multicomponent catalysts listed in 1), 2) and 3) below are used. 1) Transition metal compound Nickel or cobalt organic carboxylate, a compound selected from organic phosphite, organic phosphate, organic sulfonate, β-diketone compound, or an organic carboxylate of nickel or cobalt Super strong acid modified compounds such as antimony hexafluoride, boron tetrafluoride, trifluoroacetic acid, acetone hexafluoride, 1,5-cyclooctadiene complex of nickel, [(η ³ -crotyl) Ni (cyclooctadiene _{)] [B ((CF 3} ) 2 C 6 H 4) 4], cyclododecatriene complex nickel, norbornadiene complexes of nickel,
A diene or triene coordinated complex, nickel or cobalt bis (triarylphosphine) dihalogen complex, [(η ³ -crotyl) Ni (cyclooctadiene)] [B ((CF ₃ ) _{2
C 6 H 4) 4] Bis} [N- (3-tert-butylsalicylidene) phenylamin
ato] Ni Ni [PhC (O ) CHPPh 2] (Ph) (PPh 3) Ni (OC (O) (C 6 H 4) PPh 2) (H) (PCy 3) Ni [OC (O) (C 6 H ₄ ) PPh ₂ ] (H) (PPh ₃₎ Ni (COD) ₂ and PPh ₃ = CHC (O) Ph [[ArN = CHC ₆ H ₃ (O) (Anth)] (Ph) (PPh _{3) Ni (Ar: 2,6- (} Pr) 2C 6 H 3, Pr: isopropyl, Anth:
9-anthracene, Ph: phenyl, Cy: Cyclohexyl) and other complexes with bidentate or tridentate ligands

2) Organoaluminum compound Methylalumoxane, ethylalumoxane, butylalumoxane, methylalumoxane partially mixed with trialkylaluminum, trimethylaluminum, triethylaluminum, triisobutylaluminum, diisobutylaluminum hydride, diethylaluminum chloride, Organoaluminum compounds such as ethyl aluminum sesquichloride and ethyl aluminum dichloride

3) Further, as compounds which can be added for improving the polymerization activity, non-conjugated diene compounds such as 1,5-cyclooctadiene and 1,5,9-cyclododecatriene, ethers of boron trifluoride, amines and phenols. Such as Lewis acid compounds such as tri (pentafluorophenyl) borane, tri (3,5-di-trifluoromethylphenyl) borane, tri (pentafluorophenyl) aluminum. Triphenylcarbenium tetrakis (pentafluorophenyl) borate, triphenylcarbenium tetrakis (3,5-di-
Trifluoromethyl-phenyl) borate, tributylammonium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, N, N-diethylanilinium tetrakis (pentafluorophenyl) borate, etc. Ionic boron compounds.

These catalyst components are used in the amounts below. That is, the nickel or cobalt compound is 0.02 to 100 mmol atom per 1 mol of the monomer, the organoaluminum compound is 1 to 5000 mol per mol atom of nickel or cobalt, the non-conjugated diene, the Lewis acid, The ionic boron compound is used in an amount of 0.2 to 100 mol per 1 mol atom of nickel or cobalt.

The cycloolefin polymer of the present invention uses a catalyst comprising a component selected from the above 1), 2) and, if necessary, 3), cyclohexane, cyclopentane,
Alicyclic hydrocarbon solvents such as methylcyclopentane, aliphatic hydrocarbon solvents such as hexane, heptane and octane,
One or more of aromatic hydrocarbon solvents such as toluene, benzene, xylene and mesitylene, halogenated hydrocarbon solvents such as dichloromethane, 1,2-dichloroethylene, 1,1 dichloroethylene, tetrachloroethylene, chlorobenzene and dichlorobenzene. It can be obtained by polymerizing 100 to 2000 parts by weight of the selected solvent with 100 to 2000 parts by weight at a temperature in the range of -20 to 100 ° C.

As a method of recovering the polymer, for example, an antioxidant is added to the obtained polymer solution, the mixture is put in a dehydrated poor solvent, the polymer is solidified, and further dried to recover the polymer. Alternatively, a method of recovering a polymer by evaporating a solvent from a polymer solution to which an antioxidant is added can be exemplified, but the method is not limited to the exemplified method.

The cyclic olefin copolymer used in the present invention has a polystyrene-reduced number average molecular weight of 10,000 to 1,000 as measured by gel permeation chromatogram using o-dichlorobenzene as a solvent. , 00
It is 0, preferably 50,000 to 500,000.
The weight average molecular weight in terms of polystyrene is 15,0.
00-1,500,000, preferably 70,000-
It is 700,000. Number average molecular weight in terms of polystyrene is less than 10,000, weight average molecular weight is 15,000
If it is less than the range, the breaking strength may be insufficient. On the other hand, the polystyrene equivalent number average molecular weight is 1,000,0.
When it is more than 00 and the weight average molecular weight is more than 1,500,000, the solution viscosity becomes high when a sheet or film-like substrate is produced by casting using a solution of a cyclic olefin copolymer, and waviness In some cases, it may be difficult to produce a sheet or film having good smoothness without warpage.

The glass transition temperature of the cyclic olefin copolymer is preferably 200 ° C. or higher, more preferably 250 to 400 ° C., particularly preferably 250 to 390.
C., and most preferably 270 to 380.degree. C. in terms of heat resistance. If the glass transition temperature is less than 200 ° C., problems such as deformation may occur in the heat step required for processing the alignment film. On the other hand, when the temperature exceeds 400 ° C., it becomes necessary to raise the processing temperature in the case of heat processing such as heat pressing, and the cyclic olefin-based copolymer may be oxidatively deteriorated during the processing.

The thermal properties of the cyclic olefin-based copolymer of the present invention are dynamic viscoelasticity because the glass transition temperature is often unclear in the measurement by a scanning differential calorimeter (DSC). The glass transition temperature of the copolymer was defined by the peak temperature of Tan δ (ratio E ″ / E ′ = Tan δ between storage elastic modulus E ′ and loss elastic modulus E ″) measured by The dynamic viscoelasticity is measured by Rheovibron DDV-01FP
Using [Orientech Co., Ltd.], the measurement frequency is 10
Hz, the temperature rising rate was 4 ° C./min, the vibration mode was a single waveform, and the vibration amplitude was 2.5 μm. The obtained peak temperature of Tan δ temperature dispersion was taken as the glass transition temperature.

As the compound which is mixed and / or condensed with the cyclic olefin-based addition copolymer of the present invention to form the composition, tetraalkoxysilane, trialkoxysilane, silanol, epoxy at the end of the condensate, A condensate of an alkoxysilane compound having a degree of polymerization of 5 to 50, which has a functional group such as an alkoxysilane or an amino group,
Examples thereof include inorganic particles such as silica, alumina, zirconia, and titania. By blending and / or, it is possible to obtain an effect that a film sheet having a small linear expansion coefficient, that is, good dimensional stability can be obtained. Of these, the tetraalkoxysilane and trialkoxysilane compounds are hydrolyzed, condensed and crosslinked in the presence of the cyclic olefin-based addition copolymer of the present invention after blending.

In these compositions, the proportion of the compound to be blended is 2 to 70 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of the cyclic olefin copolymer of the present invention. Partly compounded. When the proportion of the compound to be blended is less than 2 parts by weight, the effects such as solvent resistance and dimensional stability are small when formed into a film or sheet. on the other hand,
If it exceeds 70 parts by weight, the transparency is often impaired. Inorganic particles, which are compounds to be added to these compositions,
Alternatively, when the compounded compound produces inorganic particles by condensation or the like, the composition is optically transparent and heat-resistant by being dispersed in the polymer with a particle size of 100 nm or less, preferably 10 nm or less. Dimensional stability is improved.

The antioxidant which can be added to the cyclic olefin copolymer of the present invention includes 2,6-
Di-t-butyl-4-methylphenol, 4,4′-thiobis- (6-t-butyl-3-methyl-phenyl),
1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2′-methylenebis (4-ethyl-6-t-butylphenol), tetrakis [methylene-3-3,5
-Di-t-butyl-4-hydroxyphenyl) propionate] methane, 3- (3,5-di-t-butyl-4-
Hydroxyphenyl) propionic acid stearate, 2,
5-di-t-butylhydroquinone, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, and other phenolic antioxidants, hydroquinone antioxidants and bis -(2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, tris (2,4-
Di-t-butylphenyl) phosphite, tetrakis (2,4-di-t-butyl-5-methylphenyl) 4,
4'-biphenylene diphosphonite, 3,5-di-t-
Butyl-4-hydroxybenzylphosphonate-diethyl ester, bis (2,4-di-t-butylphenyl)
Pentaerythritol-di-phosphite, tris (4
-Methoxy-3,5-diphenyl) phosphite, tris (nonylphenyl) phosphite, and other phosphorus-based secondary antioxidants dilauryl-3,3'-thiodipropionate, sulfur-based 2-mercaptobenzimidazoles, etc. Secondary antioxidants and the like can be mentioned, and a compound selected from these can be added in the range of 0.05 to 5 parts by weight per 100 parts by weight of the polymer.

The substrate material producing method of the present invention is illustrated below, but the present invention is not limited to this example. First, a cyclic olefin copolymer is prepared in a solvent having a low water content to prepare a polymer solution containing a crosslinking catalyst and having a polymer solid content of 10 to 40% by weight. Next, it is cast, and the solvent is gradually evaporated at a temperature in the range of room temperature to 250 ° C. to form a sheet or film having a predetermined thickness.
Thereafter, the sheet or film is exposed to hot water or steam at 100 to 200 ° C. to obtain a molded product crosslinked by a siloxane bond by hydrolysis / condensation of the reactive silyl group in the cyclic olefin-based copolymer. . Further, if necessary, by heating at 150 to 250 ° C. under an inert gas such as argon or nitrogen or under reduced pressure, a crosslinked molded body from which water and residual solvent are removed can be obtained. The degree of swelling of the thus obtained crosslinked product measured with toluene at 25 ° C. is preferably 300% or less from the viewpoint of solvent resistance and dimensional stability. More preferably, it is 200% or less. The degree of swelling can be easily adjusted by the temperature of hot water or steam, the exposure time of the sheet or film to hot water or steam, the amount of the crosslinking catalyst, and the like. As a hydrolysis / condensation catalyst, organic acids such as organic carboxylic acid, organic sulfonic acid, organic sulfinic acid, organic phosphoric acid, and organic phosphorous acid, and Al, Mg, Zn, B
a, Ca, Sb, Si, Ge, Sn, Ti, Zr, V,
Metal compounds such as alcohol salts, thiol salts, phenol salts, β-diketone salts, organic carboxylic acid salts, oxides and halides of metals such as Y, Sm, Yb and Sc, amine compounds, quaternary alkyl ammonium salts, etc. However, it is preferable that the organic carboxylic acid, organic sulfonic acid, organic sulfinic acid, organic phosphoric acid, organic phosphorous acid, which does not change during molding of a sheet or a film and exhibits a catalytic action by being hydrolyzed at a high temperature, is used. Are preferred. These catalysts are used in the range of 0.001 to 5 parts by weight per 100 parts by weight of the cyclic olefin copolymer.

The liquid crystal alignment film-forming substrate of the present invention can be manufactured by a known method using the above substrate. For example, an ITO electrode is formed on the surface of a liquid crystal alignment film-forming substrate obtained by cast molding as described above, and a liquid crystal alignment agent is printed on the ITO electrode using a printing machine and dried to form a film of the liquid crystal alignment agent. Can be formed to obtain a liquid crystal alignment film forming substrate. The ITO electrode can be formed by a known method such as sputtering, and the electrode film thickness is preferably 10 to 500 μm.
m, and more preferably 20 to 300 μm. As the liquid crystal aligning agent, known ones can be used, and examples thereof include an aligning agent using an organic polymer such as polyamic acid and polyimide. The thickness of the liquid crystal alignment film is preferably 5 to 100 nm, more preferably 20 to 80 nm.

An example of producing a liquid crystal display element from the liquid crystal alignment film forming substrate of the present invention is shown below. That is, after rubbing the liquid crystal alignment film, it is immersed in isopropyl alcohol or the like and then heat-treated. After applying an adhesive containing aluminum oxide spheres having a predetermined diameter to each outer edge of the obtained pair of substrates for forming a liquid crystal alignment film, the liquid crystal alignment films are superposed on each other and pressure-bonded to cure the adhesive. Let Next, after filling the liquid crystal between the pair of substrates through the liquid crystal injection port, the liquid crystal injection port is sealed, and polarizing plates are attached to both outer surfaces of the substrates to form a liquid crystal display element. The liquid crystal alignment film-forming substrate of the present invention has excellent heat resistance, solvent resistance, and dimensional stability, so that it can be baked at a high temperature without deformation to form a liquid crystal alignment film, and has excellent transparency. As described above, by using the liquid crystal alignment film forming substrate of the present invention, a liquid crystal display device which is lighter in weight than the liquid crystal display device using a glass substrate, is less likely to be damaged even when dropped, and has no display unevenness can be obtained.

[0043]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In addition, parts and% in the examples
Are parts by weight and% by weight unless otherwise specified.

The weight average molecular weight, number average molecular weight, T
The peak temperature of an δ, display unevenness, etc. were measured by the following methods. Weight average molecular weight, number average molecular weight; Waters (WAT
ERS) 150C type gel permeation chromatography (GPC) apparatus, using Tosoh Co., Ltd. H type column, it measured at 120 degreeC using o-dichlorobenzene as a solvent. The obtained molecular weight is a standard polystyrene conversion value.

Tan δ peak temperature (glass transition temperature): Polymer glass at the peak temperature of dynamic viscoelasticity Tan δ (ratio E ″ / E ′ = Tan δ between storage elastic modulus E ′ and loss elastic modulus E ″). The transition temperature was measured. Rheovibron DDV-01FP (manufactured by Orientec Co., Ltd.) was used to measure the dynamic viscoelasticity. The measurement frequency was 10 Hz, the temperature rising rate was 4 ° C./min, the vibration mode was a single waveform, and the vibration amplitude was 2. .5μ
It was carried out under the condition of m, and the peak temperature of the obtained temperature dispersion of Tan δ was obtained.

Total Light Transmittance of Film: ASTM D1
Test piece (film) with a thickness of 100 μm according to 003
The total light transmittance of was measured. Whether film dissolves in liquid crystal: thickness 50-250 μm,
The film (sheet) surface after dropping one drop (about 20 mg) of nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) on a film or sheet having a length of 2 cm and a width of 2 cm and heating at 150 ° C. for 1 hour in the atmosphere Was visually evaluated. Dissolution: Dropping surface turbid or deformed Slightly dissolved; Dropping surface cloudy or slightly deformed No dissolution; Dropping surface not deformed 25 ° C Toluene swelling degree: thickness 50 to 250 μm, vertical 2
A film or sheet having a size of 2 cm × 2 cm was immersed in toluene at 25 ° C. for 3 hours, and the degree of swelling was calculated from the weight ratio before and after the immersion. (Those that did not swell at all were set to 100%.) Display unevenness of the substrate: The following criteria were evaluated by visual evaluation. No display unevenness: A good display with no display unevenness can be obtained after applying a voltage to the liquid crystal display element. Display unevenness: After applying a voltage to the liquid crystal display element, display is uneven and a good display cannot be obtained.

Example 1 Under a nitrogen atmosphere, 89.3 g of 2-norbornene as a monomer was placed in a 2,000 ml glass reaction vessel.
(950 mmol), 5-triethoxysilyl-2-norbornene (8.6 g, 50 mmol) and toluene (490 g) were charged and the temperature of the reaction system was adjusted to 30 ° C. Then 1,5-cyclooctadiene 1 mmol, 1
10 mmol of hexene, 1 mmol atom of boron trifluoride as a Ni atom, which is a reaction product of antimony hexafluoride and nickel octoate (reacted at a molar ratio of 1: 1 at 0 ° C.) 9 mmol of an ethyl ether complex and 10 mmol of triethylaluminum were added, and polymerization was carried out at 30 ° C. for 2 hours. The conversion rate of the monomer to the polymer was 95%. 30 mmol of lactic acid was added to the polymer solution to react with the catalyst component, and the catalyst component was transferred to the aqueous phase with 500 ml of water for decatalysis. This decatalyzing operation was repeated once again. Then 2,000
The polymer solution was put into ml of isopropanol to coagulate the polymer, and unreacted monomer and a slight amount of catalyst component remaining were removed from the polymer. The solidified polymer was dried under reduced pressure at 90 ° C. for 17 hours to obtain a polymer. (This is referred to as polymer A.)

From the ¹ H-NMR analysis of 270 MH _Z of polymer A (proton nuclear magnetic resonance analysis), the proportion of structural units derived from 5-triethoxysilyl-2-norbornene was 4.9 mol%. . The number average molecular weight is 1 as determined by gel permeation chromatography (GPC).
It was 23,000 and the weight average molecular weight was 208,000. The glass transition temperature of this polymer A measured by dynamic viscoelasticity was 375 ° C.

For 100 parts of polymer A, pentaerythrityl-tetrakis [3- (3,5
-Di-t-butyl-4-hydroxyphenyl) propionate] 0.9 parts, tris (2,4-di-t-butylphenyl) phosphite 0.9 part, and a crosslinking agent tributyl phosphite of 0.5. A toluene solution of the polymer A having a solid content of 22% was prepared by adding a part thereof. This solution is cast, and in order to remove the toluene solvent, 200 ° C., 3 hours,
By heating under reduced pressure, a film having a thickness of 200 μm was produced. In order to further crosslink this film, heat treatment was performed for 2 hours under steam at 150 ° C., and drying was performed under vacuum at 200 ° C. for 1 hour. Various evaluations were performed using this film. The results are shown in Table 1.

As a substrate for a liquid crystal display element, a thickness of 0.4 m was obtained by casting and crosslinking with steam in the same manner as above.
m sheet substrate was produced. An ITO electrode was formed on this substrate to obtain a liquid crystal display device substrate. Liquid crystal aligning agent (JS
R Co., Ltd., trade name AL1000) is printed on a substrate for liquid crystal display device having an ITO electrode having an area of 2 cm ² by using a flexographic printing machine, and dried on a hot plate at 230 ° C. for 10 minutes to form a film. A liquid crystal alignment film having a thickness of 60 nm was formed and used as a liquid crystal alignment film formation substrate. The liquid crystal alignment film was rubbed with a rubbing machine having a roll around which a cloth made of nylon was wound, at a roll rotation speed of 500 rpm, a stage moving speed of 3 cm / sec, and a foot pressing length of 0.4 mm. The two substrates for liquid crystal alignment film formation after the rubbing treatment were immersed in isopropyl alcohol for 1 minute, and then heated on a hot plate at 100 ° C. for 5 minutes.

After applying the epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm to the outer edges of the pair of substrates for forming the liquid crystal alignment film after the heat treatment, the liquid crystal alignment films are superposed so as to face each other. And pressure-bonded to cure the adhesive. Then, a nematic type liquid crystal (MLC-6, manufactured by Merck & Co., Inc.) is inserted between the pair of substrates which are superposed from the liquid crystal inlet.
221) was filled, the liquid crystal injection port was sealed with an acrylic photo-curing adhesive, and polarizing plates were attached to both outer surfaces of the substrate to prepare a liquid crystal display element. When a voltage was applied to the obtained liquid crystal display element, good display without display unevenness was obtained. The evaluation results are shown in Table 1.

Example 2 In Example 1, 2-norbornene 8 was used as a monomer.
4.6 g (900 mmol), 3-tricyclo [4.
3.0.1 ^2,5 ] decene 6.8 g (50 mmol), 5
-Triethoxysilyl-7-oxa-2-norbornene was used in the same manner as in Example 1 except that 12.9 g (50 mmol) was used. This polymer is referred to as polymer B.

5-triethoxysilyl-7 in polymer B
The proportion of structural units derived from -oxa-2-norbornene is 4.1 mol%, 3-tricyclo [4.3.0.
The ratio of the structural unit derived from 1 ^2,5 ] decene was 4.3 mol%. The number average molecular weight was 106,000 and the weight average molecular weight was 189,000. The glass transition temperature of the polymer B was 390 ° C. About 2 as in Example 1
It was made to have a thickness of 00 μm and further cross-linked for evaluation. Further, a substrate for liquid crystal display was produced in the same manner as in Example 1. The results are shown in Table 1.

Example 3 In Example 1, as a monomer, 2-norbornene 9 was used.
Polymer C was obtained in the same manner as in Example 1 except that 00 mmol, styrene 50 mmol, and 5-triethoxysilyl-2-norbornene 50 mmol were used. The conversion rate to a polymer was 89%. The content of structural units derived from styrene was determined by the calibration curve method using the characteristic absorption at 699 cm ^-1 of the infrared absorption spectrum, and was found to be 3.2 mol%. The proportion of structural units derived from 5-triethoxysilyl-2-norbornene was 4.3 mol%.
The polymer C had a number average molecular weight of 66,000 and a weight average molecular weight of 119,000. In the same manner as in Example 1,
A 200 μm crosslinked film and a 0.4 mm crosslinked substrate were prepared and evaluated. When a voltage was applied to the obtained liquid crystal display element, good display without display unevenness was obtained.
The evaluation results are shown in Table 1.

Example 4 In Example 1, 2-norbornene 70 was used as a monomer.
0 mmol, 5-n-hexyl-2-norbornene 22
0 mmol, 8-methyl-8-carboxymethyl, 3-
Tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10] 50 mmol of 5-triethoxysilyl-2-norbornene 30
Polymer D was obtained in the same manner as in Example 1 except that mmol was used. The conversion rate to the polymer was 74%. Polymer D has a number average molecular weight of 82,000 and a weight average molecular weight of 1
It was 86,000. The proportion of structural units derived from 5-n-hexyl-2-norbornene was 20.8 mol% in all repeating units (polymer), and was 8-methyl-8-carboxymethyl-3-tetracyclo [4.4. .0.1
^2,5 . The proportion of structural units derived from [ ^17,10 ] was 3.6 mol%, and the proportion of structural units derived from 5-triethoxysilyl-2-norbornene was 2.8 mol%. Example 1
A crosslinked film and a crosslinked substrate were prepared and evaluated in the same manner as in. When a voltage was applied to the obtained liquid crystal display element, good display without display unevenness was obtained. The evaluation results are shown in Table 1.

Comparative Example 1 The polymer A of Example 1 was cast only, the cross-linking agent tributyl phosphite was not used, and the steam treatment was not performed to prepare a non-crosslinked film and a display element substrate. The results are shown in Table 1.

Comparative Example 2 Using the same monomers as in Example 1, 10 mmol of acetonitrile palladium (II) bis (tetrafluoroborate) was used as a polymerization catalyst, and chlorobenzene 500 was used as a solvent.
Polymerization was carried out at 30 ° C. for 10 hours using g. The conversion rate to the polymer was 85%. The polymer F was obtained by treating in the same manner as in Example 1. The number average molecular weight of the polymer F is 8,
The weight average molecular weight was 900 and 16,000.

Example 5 Tetraethoxysilane (TEOS) was added to Polymer A 10
A 200 μm film was prepared in the same manner as in Example 1 except that 20 parts was further added to 0 part. The results are shown in Table 1.

Example 6 Hydrophobized xylene / toluene (50/50 weight ratio) solvent colloidal silica (solid content 30%) was used as silica, and 5 parts were further added to 100 parts of Polymer A. A 200 μm film was prepared in the same manner as in Example 1. The results are shown in Table 1.

[0060]

[Table 1]

[0061]

The liquid crystal alignment film-forming substrate of the present invention is excellent in heat resistance and can be baked at a high temperature without deformation to form a liquid crystal alignment film and is excellent in transparency. When the above substrate is used, a liquid crystal display device which is lighter in weight than the liquid crystal display device using a glass substrate, is less likely to be damaged when dropped, and has no display unevenness can be obtained.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02F 1/1333 500 G02F 1/1333 500 (72) Inventor Tsuyoshi Hirai 2-11-24 Tsukiji, Chuo-ku, Tokyo No. 2 F090 term in JSR Co., Ltd. BB01P BB01Q BC43P CA04 CA05 DA01 DA25 DA36 JA32

Claims (7)

[Claims] 1. A liquid crystal alignment film-formed substrate comprising an electrode formed on a substrate and a liquid crystal alignment film formed on the electrode, wherein the substrate is a repeating unit (a) represented by the following general formula (1).
And a cyclic olefin-based copolymer containing a repeating unit (b) represented by the following formula (2), wherein the polystyrene-converted number average molecular weight is 10,000 to 1,000,000. A substrate for forming a liquid crystal alignment film, which comprises a crosslinked material crosslinked by a siloxane bond. [Chemical 1] [In the formula (1), A ^{1 to} A ⁴ are each independently a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or — (CR ¹ R ² ) _f Si (OR ³ ) _g R ⁴ _{( 3-g), - (CR} 1 R 2) f Si (R 3 R 4) OSi (OR 3) g R 4
_{(3-g), - (} CR 1 R 2) f C (O) O (CH 2) h Si (OR 3) g
R ⁴ _(3-g) represents an alkoxysilyl group, an aryloxysilyl group or a hydrolysis / condensation residue thereof, wherein at least one of A ^{1 to} A ⁴ is an alkoxysilyl group, an aryloxysilyl group or These hydrolysis / condensation residues are shown. here,
R ¹ and R ² are each independently a hydrogen atom or a carbon number 1
To 20 hydrocarbon groups, R ³ represents an alkyl group, an alkenyl group, an aryl group, and a cycloalkyl group having 1 to 10 carbon atoms, and R ⁴ represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms. Represents a group, f and h are integers of 0 to 5,
g represents an integer of 1 to 3. Further, Y is -CH ₂ - indicates a or -O-, m is 0 or 1. ] [Chemical 2] [In the formula (2), B ¹ , B ² , B ³ , and B ⁴ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, an alkenyl group, a cycloalkyl group, a halogen atom,
Halogenated hydrocarbon group, or - indicates a (CH ₂₎ a polar group represented by _j X. Here, X is -C (O) OR ⁵ , -OC
(O) R ⁶ , R ⁵ and R ⁶ are alkyl groups having 1 to 20 carbon atoms, alkenyl groups, aryl groups, cycloalkyl groups and halogen substituents thereof, and j is an integer of 0 to 5 .
Further, B ^{1 to} B ⁴ are alkylidene groups formed by B ¹ and B ² or B ³ and B ⁴ , B ¹ and B ⁴ , B ¹ and B ³ or B ² and B ⁴
Also included are cycloalkylene groups and cycloalkenylene groups formed by. n represents an integer of 0 to 2. ] 2. The liquid crystal alignment film forming substrate according to claim 1, wherein the degree of swelling of the crosslinked product in toluene measured at 25 ° C. is 300% or less. 3. The liquid crystal alignment film forming substrate according to claim 1, wherein the cyclic olefin-based copolymer further contains a repeating unit (c) represented by the general formula (3). - (CH ₂ -CHR ⁷⁾ - in · · · (3) [Equation (3), R ⁷ is a hydrogen atom or an aryl group, an alkyl-substituted Ari - indicating group, a trialkylsilyl group. ] 4. The liquid crystal alignment film forming substrate according to claim 1, wherein the cyclic olefin copolymer has a glass transition temperature of 200 ° C. or higher. 5. The cyclic olefin-based copolymer is blended with at least one compound selected from the group of tetraalkoxysilane compounds, trialkoxysilane compounds and condensates of these alkoxysilane compounds. 4. The liquid crystal alignment film forming substrate according to any one of items 4 to 4. 6. The cyclic olefin-based copolymer is blended with at least one metal oxide selected from the group consisting of silica, alumina, zirconia and titania.
5. A substrate for forming a liquid crystal alignment film according to any one of 5 to 5. 7. A liquid crystal display device using the substrate for forming a liquid crystal alignment film according to claim 1.