JP4544438B2 - Liquid crystal aligning agent, method for forming liquid crystal aligning film, and liquid crystal display element - Google Patents

Description

  The present invention relates to a liquid crystal alignment agent, a method for forming a liquid crystal alignment film, and a liquid crystal display element.

Conventionally, a nematic liquid crystal having positive dielectric anisotropy is sandwiched with a substrate with a transparent electrode having a liquid crystal alignment film, and the major axis of liquid crystal molecules is continuously twisted between 0 and 360 ° between the substrates as necessary. There are known liquid crystal display elements having a liquid crystal cell such as a TN (Twisted Nematic) type, a STN (Super Twisted Nematic) type, an IPS (In Plane Switching) type, and the like (Japanese Patent Laid-Open No. Sho 56-91277). Gazette and JP-A-1-120528).
In such a liquid crystal cell, it is necessary to provide a liquid crystal alignment film on the substrate surface in order to align liquid crystal molecules in a predetermined direction with respect to the substrate surface. This liquid crystal alignment film is usually formed by a method (rubbing method) in which the surface of the organic film formed on the substrate surface is rubbed in one direction with a cloth material such as rayon. However, when the liquid crystal alignment film is formed by a rubbing process, dust and static electricity are likely to be generated in the process, so that there is a problem that dust adheres to the alignment film surface and causes display defects. In particular, in the case of a substrate having a TFT (Thin Film Transistor) element, there has been a problem that the circuit damage of the TFT element occurs due to the generated static electricity, resulting in a decrease in yield. Furthermore, in liquid crystal display elements that will be further refined in the future, unevenness is generated on the substrate surface as the density of pixels increases, and it is becoming difficult to perform rubbing treatment uniformly.
As another means of aligning the liquid crystal in the liquid crystal cell, light that imparts liquid crystal alignment ability by irradiating a photosensitive thin film such as polyvinyl cinnamate, polyimide, or azobenzene derivative formed on the substrate surface with polarized or non-polarized radiation. Orientation methods are known. According to this method, uniform liquid crystal alignment can be realized without generating static electricity or dust (JP-A-6-287453, JP-A-10-251646, JP-A-11-2815, JP 11-152475 A, JP 2000-144136 A, JP 2000-319510 A, JP 2000-281724 A, JP 9-297313 A, JP 2003-307736 A, JP. 2004-163646 and JP-A-2002-250924).
By the way, in a liquid crystal cell of TN (Twisted Nematic) type, STN (Super Twisted Nematic) type, etc., the liquid crystal alignment film needs to have a pretilt angle characteristic in which liquid crystal molecules are inclined and aligned at a predetermined angle with respect to the substrate surface. There is. In the case of forming a liquid crystal alignment film by the photo-alignment method, the pretilt angle is usually given by tilting the incident direction of the irradiated radiation to the substrate surface from the substrate normal.

On the other hand, a vertical (homeotropic) alignment mode in which liquid crystal molecules having negative dielectric anisotropy are aligned perpendicularly to a substrate is also known as an operation mode of a liquid crystal display element different from the above. In this operation mode, when a voltage is applied between the substrates and the liquid crystal molecules are tilted in the direction parallel to the substrate, the liquid crystal molecules must be tilted from the substrate normal direction to one direction in the substrate surface. There is. As a means for this, for example, a method of providing protrusions on the substrate surface, a method of providing stripes on the transparent electrode, or using a rubbing alignment film, liquid crystal molecules are slightly directed from the substrate normal direction to one direction in the substrate surface. A method of tilting (pretilting) has been proposed.
The photo-alignment method is known to be useful as a method for controlling the tilt direction of liquid crystal molecules in a vertical alignment mode liquid crystal cell. That is, it is known that the tilt direction of liquid crystal molecules when a voltage is applied can be uniformly controlled by using a vertical alignment film imparted with alignment regulating ability and pretilt angle expression by a photo-alignment method (Japanese Patent Laid-Open No. 2003-307736). No., JP-A No. 2004-163646, JP-A No. 2004-83810, JP-A No. 9-21468 and JP-A No. 2003-114437).
Thus, the liquid crystal alignment film manufactured by the photo-alignment method can be effectively applied to various liquid crystal display elements. However, the conventional photo-alignment film has a problem that a large amount of radiation is required to obtain a large pretilt angle. For example, when a liquid crystal alignment ability is imparted to a thin film containing an azobenzene derivative by a photo-alignment method, in order to obtain a sufficient pretilt angle, radiation whose optical axis is inclined from the substrate normal is 10,000 J / m ² or more. It has been reported that irradiation has to be performed (see Japanese Patent Application Laid-Open Nos. 2002-250924 and 2004-83810 and J. of the SID 11/3, 2003, p579).

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal alignment film having good liquid crystal alignment ability even with a small exposure amount by irradiation with polarized or non-polarized radiation without performing a rubbing treatment. An object of the present invention is to provide a liquid crystal display element excellent in various performances such as a liquid crystal aligning agent to be applied, a manufacturing method of the liquid crystal alignment film, display characteristics, and reliability.

According to the present invention, the above object of the present invention is firstly
Following formula (1)

(In Formula (1), ^{Y 1} represents a hydroxyl group, an alkoxyl group having 1 to 10 carbon atoms, an alkyl group or an aryl group having 6 to 20 carbon atoms having 1 to 20 carbon atoms.)
At least one selected from the group consisting of a polysiloxane having a repeating unit represented by the formula:
A radiation-sensitive polysiloxane obtained by reacting a cinnamic acid derivative having at least one group selected from the group consisting of an alkenyl group and an alkynyl group , and
It is achieved by a liquid crystal aligning agent containing at least one polymer selected from the group consisting of polyamic acid and polyimide .

The above object of the present invention is secondly,
The liquid crystal aligning agent is applied to form a coating film, and the coating film is irradiated with radiation.
Thirdly, the object of the present invention is as follows.
This is achieved by a liquid crystal display element comprising a liquid crystal alignment film formed from the above liquid crystal alignment agent.

  The liquid crystal aligning agent of the present invention is a liquid crystal aligning film having excellent liquid crystal aligning properties and electrical characteristics with a small radiation dose as compared with a liquid crystal aligning agent conventionally known as a liquid crystal aligning agent to which a photo-alignment method can be applied. Can be formed. Therefore, when this liquid crystal alignment film is applied to a liquid crystal display element, the liquid crystal display element can be manufactured at a lower cost than before, and the various properties such as display characteristics and reliability are excellent. Therefore, these liquid crystal display elements can be effectively applied to various devices, and can be suitably used for devices such as desk calculators, watches, clocks, counting display boards, word processors, personal computers, and liquid crystal televisions.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention is at least one selected from the group consisting of a polysiloxane having a repeating unit represented by the above formula (1), a hydrolyzate thereof and a condensate of the hydrolyzate (hereinafter referred to as “polyester”). Siloxane (1) "),
It contains a radiation-sensitive polysiloxane obtained by reacting a cinnamic acid derivative having at least one group selected from the group consisting of alkenyl groups and alkynyl groups.

[Polysiloxane (1)]
The polysiloxane (1) used in the present invention is at least one selected from the group consisting of a polysiloxane having a repeating unit represented by the above formula (1), a hydrolyzate thereof and a condensate of the hydrolyzate. is there.
Examples of the alkoxy group having 1 to 10 carbon atoms of Y ¹ in the above formula (1) include a methoxyl group and an ethoxyl group; examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group and an n-propyl group N-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-lauryl group, n-dodecyl group, n-tridecyl group N-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl group, etc .; Each group can be mentioned.
The polysiloxane (1) may be linear, ladder (ladder), cage, cubic or random, or have two or more of these structures in one molecule It may be a mixture of two or more polysiloxanes having different structures.
Polysiloxane (1) preferably has a polystyrene-equivalent weight average molecular weight of 200 to 150,000, more preferably 200 to 100,000, and more preferably 1, as measured by gel permeation chromatography (GPC). It is preferable that it is 000-10,000.
Examples of the polysiloxane (1) particularly preferably used in the present invention include the following formula (1-1)

Cubic octakis (hydridosilsesquioxane) represented by the following formulas (1-2) to (1-6)

(In the above formula, n1 and n2 are each an integer from 3 to 8, n3 and n5 are each an integer from 1 to 50, n4 and n6 are each an integer from 0 to 1,000, and n7 is from 5 to 5) (It is an integer of 10.)
And the like, and the like. As polysiloxane (1) used by this invention, the compound represented by the said Formula (1-1) is preferable.
In the polysiloxane (1) preferably used in the present invention, the weight of the polysiloxane corresponding to 1 mol of silicon-hydrogen bonds is preferably 50 to 5,000 g / mol, and preferably 50 to 500 g / mol. Is more preferable.
The octakis (hydridosilsesquioxane) represented by the above formula (1-1) particularly preferable as the polysiloxane (1) used in the present invention is, for example, Journal of American Chemical Society, Vol. 92, No. 19, P5586 ( (1970).
As polysiloxane (1) in this invention, you may use what is marketed. For example, the compound represented by the above formula (1-1) is TAL MATERIALS Inc. Is available from

[Cinnamic acid derivatives]
The cinnamic acid derivative having at least one group selected from the group consisting of alkenyl groups and alkynyl groups used in the present invention includes, for example, at least one group selected from the group consisting of alkenyl groups and alkynyl groups, and formula

And a compound having a divalent group represented by: Such cinnamic acid derivatives include those represented by the following formula (2):

(In Formula (2), R ¹ is a C1-C40 monovalent organic group containing a C1-C40 alkyl group or an alicyclic group, provided that a part of hydrogen atoms of the alkyl group or All may be substituted with fluorine atoms, R ² is a single bond, an oxygen atom, —COO— or —OCO—, R ³ is a divalent aromatic group, a divalent alicyclic group, 2 R ⁴ is a monovalent heterocyclic group or a divalent fused cyclic group, and R ⁴ is a single bond, an oxygen atom, ^* —COO— or ^* —OCO— (where the bond marked with “*” is R ³ and R ⁵ is a single bond, a methylene group or an alkylene group having 2 to 10 carbon atoms, and when R ⁵ is a single bond, R ⁶ is —CH═CH ₂ or —C≡CH, When R ⁵ is a methylene group or an alkylene group, R ⁶ is —CH═CH ₂ , —C≡CH or —OOC—C H = CH ₂ , R ⁷ is a fluorine atom or a cyano group, X ¹ is an oxygen atom or the following formula

(However, the bond marked with “*” is on the R ⁵ -R ⁶ side.)
A is an integer of 0 to 3, and b is an integer of 0 to 4. )
Or a compound represented by the following formula (3)

(In the formula (3), R ⁸ is a monovalent organic group having 3 to 40 carbon atoms containing an alkyl group or an alicyclic group having 1 to 40 carbon atoms, provided that a portion of the hydrogen atoms of the alkyl group or All may be substituted with fluorine atoms, R ⁹ is an oxygen atom, —COO— or —OCO—, and R ¹⁰ is a divalent aromatic group, a divalent heterocyclic group or a divalent condensed group. A cyclic group, R ¹¹ is a single bond, —OCO— (CH ₂ ) _e — ^* or —O— (CH ₂ ) _g — ^* (where a bond marked with “*” binds to R ¹² . E) and g are each an integer of 0 to 10, R ¹² is —CH═CH ₂ , —C≡CH or —OOC—CH═CH ₂ , and R ¹³ is a fluorine atom or cyano. X ² is an oxygen atom, a phenylene group or the following formula

(However, the bond marked with “*” binds to R ^8. )
C is an integer of 0 to 3, and d is an integer of 0 to 4. )
It is preferable that it is a compound represented by these.

The alkyl group having 1 to 40 carbon atoms of R ¹ in the above formula (2) is, for example, an alkyl group having 1 to 20 carbon atoms, provided that part or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms. It is preferable that Examples of such alkyl groups include, for example, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-lauryl group, n-dodecyl group, n -Tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl group, 4,4,4-trifluorobutyl group, 4,4,5,5,5-pentafluoropentyl, 4,4,5,5,6,6,6-heptafluorohexyl group, 3,3,4,4,5,5,5-heptafluoropentyl Group, 2,2,2-trifluoroethyl group, 2,2,3,3,3-pentafluoropropyl group, 2- (perfluorobutyl) ethyl group, 2- (perfluorooctyl) ethyl group, 2- (Perful , And the like Rodeshiru) ethyl. The monovalent organic group having 3 to 40 carbon atoms containing an alicyclic group R ^1, may include, for example Koresuteniru group, cholestanyl group, an adamantyl group.
Examples of the divalent aromatic group for R ³ include 1,4-phenylene group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group, 2,3,5,6- A tetrafluoro-1,4-phenylene group, etc .; as the divalent alicyclic group of R ³ , for example, a 1,4-cyclohexylene group, etc .; as the divalent heterocyclic group of R ³ , For example, 1,4-pyridylene group, 2,5-pyridylene group, 1,4-furanylene group and the like; As the divalent condensed cyclic group for R ³ , for example, a naphthylene group and the like can be exemplified.

  Examples of the compound represented by the formula (2) include cinnamic acid derivatives having an alkenyl group, such as the following formulas (2-P1) to (2-P15) and (2-A1) to (2-A15).

(In the formula, R ¹ has the same meaning as in the above formula (2), and i is an integer of 0 to 10).
A compound represented by each of the above;
Examples of cinnamic acid derivatives having an alkynyl group include the following formulas (2-P16) to (2-P21)

(In the formula, R ¹ has the same meaning as in the above formula (2), and f is an integer of 0 to 10).
The compounds represented by each of the above can be mentioned.

The alkyl group having 1 to 40 carbon atoms of R ⁸ in the above formula (3) is, for example, an alkyl group having 1 to 20 carbon atoms, provided that part or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms. It is preferable that Examples of such an alkyl group include those exemplified as the alkyl group for R ¹ in the above formula (2). Examples of the monovalent organic group having 3 to 40 carbon atoms including the alicyclic group of R ⁸ include a cholestenyl group, a cholestanyl group, and an adamantyl group.
Examples of the divalent aromatic group, divalent heterocyclic group or divalent condensed cyclic group represented by R ¹⁰ include, for example, the divalent aromatic group represented by R ³ in the above formula (2) and divalent complex. What was illustrated as a cyclic group or a bivalent condensed cyclic group, respectively can be mentioned.
The phenylene group for X ² is preferably a 1,4-phenylene group.
Examples of the compound represented by the formula (3) include cinnamic acid derivatives having an alkenyl group, for example, the following formulas (3-P1) to (3-P5) and (3-A1) to (3-A3)

(In the formula, R ⁸ has the same meaning as in the above formula (3), and h and j are each an integer of 1 to 10.)
A compound represented by each of the above;
Examples of cinnamic acid derivatives having an alkynyl group include the following formulas (3-P6) to (3-P8) and (3-A4) and (3-A5)

(In the formula, R ⁸ has the same meaning as in the above formula (3), and h and j are each an integer of 1 to 10.)
And the like can be mentioned respectively.
The compound represented by the above formula (2) or (3) can be synthesized by a conventional method of organic chemistry.

For example, the compound represented by the above formula (2-P1) is reacted with, for example, hydroxycinnamic acid and an alkyl halide having an alkyl group corresponding to R ¹ in the presence of a suitable base such as potassium carbonate. Then, it is hydrolyzed with an appropriate aqueous alkali solution such as sodium hydroxide to obtain a cinnamic acid derivative having a carboxyl group, and this carboxyl group is converted into a compound CH ₂ = CH (CH ₂ ) _k X ' , K is an integer of 1 to 6, and X ′ is a halogen atom.), And preferably in potassium carbonate.
In addition, the compound represented by the above formula (2-A1) is obtained by reacting the carboxyl group of a cinnamic acid derivative having a carboxyl group synthesized in the same manner as described above with thionyl chloride to obtain an acid chloride, and then reacting with hydroxyethyl. It can be obtained by reacting acrylate with an appropriate base catalyst such as triethylamine.
The compound represented by the above formula (2-P2) and the compound represented by the above formula (2-A2) are hydroxycinnamic acid and alkyl having an alkyl group corresponding to R ¹ as a cinnamic acid derivative having a carboxyl group. Except for using a compound obtained by reacting a carboxylic acid chloride with a suitable base such as potassium carbonate at a temperature of 0 ° C. to room temperature, the compound represented by the above formula (2-P1) or the above formula ( It can be obtained in the same manner as the synthesis of the compound represented by 2-A1).
The compound represented by the above formula (2-P4) and the compound represented by the above formula (2-A4) have methyl hydroxybenzoate and an alkyl group corresponding to R ¹ as a cinnamic acid derivative having a carboxyl group. An alkyl halide or alkyl tosylate is reacted at room temperature to 100 ° C. in the presence of a suitable base such as potassium carbonate, and then hydrolyzed with a suitable alkaline aqueous solution such as sodium hydroxide, and this is further reacted with thionyl chloride. In the presence of a compound obtained by reacting with hydroxycinnamic acid at a temperature of 0 ° C. to room temperature in the presence of a suitable base such as potassium carbonate, the above formula (2-P1) is obtained. Or a compound represented by the above formula (2-A1).
The compound represented by the above formula (2-P5) and the compound represented by the above formula (2-A5) are, as cinnamic acid derivatives having a carboxyl group, an alkyl having a hydroxybenzoic acid and an alkyl group corresponding to R ^1. After reacting with carboxylic acid chloride in the presence of a suitable base such as triethylamine at a temperature of 0 ° C. to room temperature, it is converted to acid chloride with thionyl chloride, and this is reacted with hydroxycinnamic acid in the presence of a suitable base such as potassium carbonate. Other than using a compound obtained by reacting at a temperature of 0 ° C. to room temperature, the same manner as in the synthesis of the compound represented by the above formula (2-P1) or the compound represented by the above formula (2-A1), respectively. Obtainable.

The compound represented by the above formula (2-P6) and the compound represented by the above formula (2-A6) are cinnamic acid derivatives having a carboxyl group, and 4-alkylbenzoic acid is converted to acid chloride with thionyl chloride. Other than the compound obtained by reacting hydroxycinnamic acid with hydroxycinnamic acid in the presence of a suitable base such as potassium carbonate at a temperature of 0 ° C. to room temperature, respectively, or a compound represented by the above formula (2-P1) It can be obtained in the same manner as the synthesis of the compound represented by (2-A1).
The compound represented by the above formula (2-P15) and the compound represented by the above formula (2-A15) are, as cinnamic acid derivatives having a carboxyl group, methyl 4-hydroxycyclohexylcarboxylate and an alkyl corresponding to R ^1. After reacting with an alkyl halide having a group in the presence of a suitable alkali such as sodium hydride or sodium metal, it is hydrolyzed with an aqueous alkali solution such as sodium hydroxide, and further acid chloride with thionyl chloride. Then, each of them is represented by the above formula (2-P1) except that a compound obtained by reacting this with hydroxycinnamic acid in the presence of a suitable base such as potassium carbonate at a temperature of 0 ° C. to room temperature is used. It can be obtained in the same manner as the synthesis of the compound or the compound represented by the above formula (2-A1).
The compound represented by the formula (2-P7) and the compound represented by the formula (2-A7) are, as cinnamic acid derivatives having a carboxyl group, 4-alkylcyclohexylcarboxyl having an alkyl group corresponding to R ^1. Except for using a compound obtained by reacting an acid chloride with thionyl chloride with hydroxycinnamic acid in the presence of a suitable base such as potassium carbonate at a temperature of 0 ° C. to room temperature, the above formula (2- It can be obtained in the same manner as the synthesis of the compound represented by P1) or the compound represented by the above formula (2-A1).
The compound represented by the above formula (2-P8) and the compound represented by the above formula (2-A8) are, as cinnamic acid derivatives having a carboxyl group, an alkyl halide corresponding to R ¹ and hydroxybenzaldehyde as potassium carbonate. Except that a compound obtained by reacting in the presence of a base to form an ether bond and then subjecting 4-acetylbenzoic acid to aldol condensation in the presence of sodium hydroxide is used in the above formula (2-P1). Or a compound represented by the above formula (2-A1). The compounds represented by each of the above formulas (2-A9) to (2-A14) and (2-P9) to (2-P14) can also be obtained by a method analogous thereto.

The compound represented by the above formula (3-P1) and the compound represented by the above formula (3-A1) have 4-iodophenol and an alkyl group corresponding to R ¹ as a cinnamic acid derivative having a carboxyl group. After reacting with alkyl acrylate using palladium and amine as a catalyst (generally referred to as “Heck reaction”), ring opening addition of a desired cyclic acid anhydride such as succinic anhydride or glutaric anhydride is performed to the reaction product. The compound obtained by this can be obtained in the same manner as the synthesis of the compound represented by the above formula (2-P1) or the compound represented by the above formula (2-A1).
The compound represented by the above formula (3-P2) and the compound represented by the above formula (3-A2) are, as cinnamic acid derivatives having a carboxyl group, 4-alkylacetophenone corresponding to R ¹ and 4-formylbenzoic acid. Similar to the synthesis of the compound represented by the above formula (2-P1) or the compound represented by the above formula (2-A1), except that the compound obtained by aldol condensation in the presence of sodium hydroxide is used. Can be obtained. The compounds represented by the above formulas (3-P3) and (3-A3) can also be obtained by a method according to this.

[Radiation sensitive polysiloxane]
The radiation-sensitive polysiloxane contained in the liquid crystal aligning agent of the present invention is obtained by reacting the polysiloxane (1) as described above with a cinnamic acid derivative, preferably by a hydrosilylation reaction in the presence of a catalyst, preferably in an organic solvent. It is a polyorganosiloxane obtained by making it.
Here, the cinnamic acid derivative is preferably 0.001 to 1.5 mol, more preferably 0.01 to 1 mol, and still more preferably 0.001 mol per mol of the silicon-hydrogen bond of the polysiloxane (1). 05-0.9 mol is used.
As the catalyst, those known as hydrosilylation catalysts can be used, and for example, a compound or complex containing platinum, rhodium or palladium can be used. Among them, a compound or complex containing platinum is preferable, and specific examples thereof include hexachloroplatinic (IV) acid hexahydrate, platinum carbonyl vinylmethyl complex, platinum-divinyltetramethyldisiloxane complex, platinum-cyclovinylmethylsiloxane complex, platinum- Examples include octyl aldehyde / octanol complex. The platinum compound or complex may be supported on a suitable carrier such as activated carbon. The amount of the catalyst used is preferably 0.01 to 10,000 ppm, more preferably 0.1 to 100 ppm, based on the weight of the cinnamic acid derivative used, as the amount of metal atoms contained in the compound or complex. It is.

As the organic solvent that can be used for the hydrosilylation reaction between the polysiloxane (1) and cinnamic acid derivative, aromatic hydrocarbons or ethers are preferable. Specific examples thereof include toluene, xylene, mesitylene, diethylbenzene, tetrahydrofuran, diethyl ether, 1, 4-dioxane, diphenyl ether and the like can be mentioned. The solvent is used in such an amount that the solid content concentration (the ratio of the weight of components other than the solvent in the reaction solution to the total weight of the solution) is preferably 0.1% by weight or more, more preferably 5 to 50% by weight. The
The reaction temperature is preferably room temperature to 250 ° C, more preferably 50 to 180 ° C. The reaction time is preferably 0.1 to 120 hours, more preferably 1 to 10 hours.

In the synthesis of the radiation-sensitive polysiloxane, when the polysiloxane (1) is reacted with the cinnamic acid derivative, a part of the cinnamic acid derivative may be replaced with an unsaturated compound having an epoxy group. By using a cinnamic acid derivative and an unsaturated compound having an epoxy group in combination, a radiation-sensitive polysiloxane crosslinkable group can be introduced, and the strength of the obtained liquid crystal alignment film can be further improved. In this case, the synthesis of the radiation-sensitive polysiloxane is preferably performed by reacting the polysiloxane (1) with a mixture composed of a cinnamic acid derivative and an unsaturated compound having an epoxy group.
Examples of the unsaturated compound having an epoxy group include allyl glycidyl ether, 1,2-epoxy-5-hexene, 1,2-epoxy-9-decene, glycidyl acrylate, 4-vinyl-1-cyclohexene 1,2 -An epoxide etc. can be mentioned. When the cinnamic acid derivative and the unsaturated compound having an epoxy group are used in combination, the proportion of the unsaturated compound having an epoxy group is preferably 50 with respect to the sum of the cinnamic acid derivative and the unsaturated compound having an epoxy group. It is less than mol%.

[Other ingredients]
The liquid crystal aligning agent of this invention contains the above radiation sensitive polysiloxane.
The liquid crystal aligning agent of the present invention may further contain other components in addition to the radiation-sensitive polysiloxane as described above as long as the effects of the present invention are not impaired. Examples of such other components include at least one polymer selected from the group consisting of polyamic acid and polyimide , a heat-sensitive crosslinking agent, a functional silane compound, and a surfactant.

At least one polymer selected from the group consisting of the above polyamic acid and polyimide is used to further improve the solution characteristics of the liquid crystal aligning agent of the present invention and the electric characteristics of the obtained liquid crystal alignment film .

[Polyamic acid]
The polyamic acid can be obtained by reacting a tetracarboxylic dianhydride and a diamine compound.
Examples of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1 , 2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4 -Cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride Anhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxy Pentylacetic acid dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,3,3a, 4,5,9b -Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro- 5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro- 5-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro -7-methyl-5- (tetrahydro-2, 5-Dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-ethyl-5- (tetrahydro-2 , 5-Dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro- 2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-ethyl-5- (tetrahydro -2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5 -(Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2 c] -furan-1,3-dione, 5- (2,5-dioxotetrahydrofuranyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, bicyclo [2.2.2]- Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 '-(tetrahydrofuran- 2 ', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy 2-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, The following formulas (T-1) to (T-14)

An aliphatic tetracarboxylic dianhydride and an alicyclic tetracarboxylic dianhydride, such as a tetracarboxylic dianhydride represented by each of the following:
Pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 1,4,5, 8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4′-bis ( 3,4-dicar Boxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidene diphthalic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2 , 2 ′, 3,3′-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis ( Triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4′-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4′-diphenylmethane dianhydride, ethylene glycol-bis ( Anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,4-butanediol-bis (anhydrotrimellitate) Retate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis ( Anhydrotrimellitate), the following formulas (T-15) to (T-18)

An aromatic tetracarboxylic dianhydride such as tetracarboxylic dianhydride represented by each of the above.
Of these, preferred are butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride. Anhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4,5,9b-hexahydro-5 (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5 (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl- 5- (Tetrahi B-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, bicyclo [2,2,2] -oct-7-ene-2,3,5 6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- ( 2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4 '-Biphenylsulfonetetracarboxylic dianhydride, 2,3', 2,3'-biphenyltetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride and the above formula (T- Examples thereof include tetracarboxylic dianhydrides represented by 1), (T-2) and (T-15) to (T-18). These tetracarboxylic dianhydrides are preferable from the viewpoint of achieving good liquid crystal alignment.

Particularly preferred tetracarboxylic dianhydrides include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4,5, 9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro- 8-Methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane-2 , 4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1, 2-dicarboxylic acid Things, 3,5,6-tricarboxy-2-carboxymethyl norbornane -2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^{2, 6]} undecane - Mention may be made of 3,5,8,10-tetraone and pyromellitic dianhydride.
These tetracarboxylic dianhydrides can be used alone or in combination of two or more.

  Examples of the diamine compound used for the synthesis of the polyamic acid include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diaminobenzanilide, 4,4′-diaminodiphenyl ether, 1,5-diaminonaphthalene, 2, 2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl, 3,3'- Ditrifluoromethyl-4,4′-diaminobiphenyl, 5-amino-1- (4′-amino Phenyl) -1,3,3-trimethylindane, 6-amino-1- (4'-aminophenyl) -1,3,3-trimethylindane, 3,4'-diaminodiphenyl ether, 3,3'-diaminobenzophenone 3,4′-diaminobenzophenone, 4,4′-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl ] Hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bi (4-aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 9,9-bis (4-aminophenyl) fluorene, 4,4′- Methylene-bis (2-chloroaniline), 2,2 ′, 5,5′-tetrachloro-4,4′-diaminobiphenyl, 2,2′-dichloro-4,4′-diamino-5,5′- Dimethoxybiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 1,4,4 ′-(p-phenyleneisopropylidene) bisaniline, 4,4 ′-(m-phenyleneisopropylidene) bisaniline, 2, 2'-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4'-diamino-2,2'-bis (to Aromatic diamines such as (rifluoromethyl) biphenyl, 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl;

1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, Tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylene methylenediamine, tricyclo [6.2.1.0 ^2,7 ] -undecylenedimethyldiamine, 4,4'-methylenebis (cyclohexylamine) Aliphatic diamines and alicyclic diamines;
2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino-2,4 -Dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 1,4-bis (3-aminopropyl) piperazine, 2,4-diamino-6-isopropoxy-1,3 , 5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl -S-triazine, 2,4-diamino-1,3,5-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6- Aminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino-1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6 Phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl -3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N'-di (4-aminophenyl) -benzidine, 6- (4-chalconyloxy) hexyloxy (2,4- Diaminobenzene), 6- (4′-fluoro-4-chalconyloxy) hexyloxy (2,4-diaminobenzene), 8- 4-Carconyloxy) octyloxy (2,4-diaminobenzene), 8- (4′-fluoro-4-chalconyloxy) octyloxy (2,4-diaminobenzene), 1-dodecyloxy-2,4 -Diaminobenzene, 1-tetradecyloxy-2,4-diaminobenzene, 1-pentadecyloxy-2,4-diaminobenzene, 1-hexadecyloxy-2,4-diaminobenzene, 1-octadecyloxy-2, 4-diaminobenzene, 1-cholesteryloxy-2,4-diaminobenzene, 1-cholestanyloxy-2,4-diaminobenzene, dodecyloxy (3,5-diaminobenzoyl), tetradecyloxy (3,5-diamino) Benzoyl), pentadecyloxy (3,5-diaminobenzoyl), hexadecyloxy ( , 5-diaminobenzoyl), octadecyloxy (3,5-diaminobenzoyl), cholesteryloxy (3,5-diaminobenzoyl), cholestanyloxy (3,5-diaminobenzoyl), (2,4-diaminophenoxy) palmitate , (2,4-diaminophenoxy) stearylate, (2,4-diaminophenoxy) -4-trifluoromethylbenzoate, the following formulas (D-1) to (D-5)

An aromatic diamine such as a diamine compound represented by each of
Aromatic diamines having heteroatoms such as diaminotetraphenylthiophene;
Metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1,4-diamino Cyclohexane, isophorone diamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylene methylenediamine, tricyclo [6.2.1.0 ^2,7 ] -undecylenedimethyldiamine, 4,4'- Aliphatic and alicyclic diamines such as methylene bis (cyclohexylamine);
Examples include diaminoorganosiloxane such as diaminohexamethyldisiloxane.

Among these, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4,4′-diaminodiphenyl ether, 4,4 ′-(p- Phenylene isopropylidene) bisaniline, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- ( 4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 4,4′-bis [(4-amino-2 -Trifluoromethyl) phenoxy] -octafluorobiphenyl, 1-hexadecyloxy-2,4-di Minobenzene, 1-octadecyloxy-2,4-diaminobenzene, 1-cholesteryloxy-2,4-diaminobenzene, 1-cholestanyloxy-2,4-diaminobenzene, hexadecyloxy (3,5-diaminobenzoyl) , Octadecyloxy (3,5-diaminobenzoyl), cholesteryloxy (3,5-diaminobenzoyl), cholestanyloxy (3,5-diaminobenzoyl), 3,6-diaminocarbazole, N-methyl-3,6- Diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N′-di (4-aminophenyl) -benzidine and the above formulas (D-1) to (D Examples of the diamine compound represented by each of -5).
These diamine compounds can be used alone or in combination of two or more.

The ratio of the tetracarboxylic dianhydride and the diamine compound used in the polyamic acid synthesis reaction is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.001 with respect to 1 equivalent of the amino group contained in the diamine compound. A ratio of 2 to 2 equivalents is preferable, and a ratio of 0.3 to 1.2 equivalents is more preferable.
The polyamic acid synthesis reaction is preferably carried out in an organic solvent under a temperature condition of preferably -20 to 150 ° C, more preferably 0 to 100 ° C. The time for the synthesis reaction is preferably 0.5 to 24 hours, more preferably 2 to 10 hours. Here, the organic solvent is not particularly limited as long as it can dissolve the synthesized polyamic acid. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide And aprotic polar solvents such as γ-butyrolactone, tetramethylurea and hexamethylphosphortriamide; and phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. Further, the amount (a) of the organic solvent used is such that the total amount (b) of the tetracarboxylic dianhydride and the diamine compound is 0.1 to 30% by weight with respect to the total amount (a + b) of the reaction solution. An amount is preferred. In addition, when using an organic solvent together with the poor solvent demonstrated below, the usage-amount (a) of the said organic solvent means the total usage-amount of an organic solvent and a poor solvent.

  For the organic solvent, alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbon, etc., which are generally believed to be poor solvents for polyamic acid, may be used in combination as long as the resulting polyamic acid does not precipitate. it can. Specific examples of such poor solvents include methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, ethyl lactate, butyl lactate, acetone, and methyl ethyl ketone. , Methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, isoamyl isobutyrate, isoamyl propionate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate , Diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol -I-propyl ether, ethylene glycol-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether List acetate, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, diisopentyl ether, etc. Can do.

When a poor solvent is used as a part of the organic solvent used when synthesizing the polyamic acid, the use ratio can be appropriately set within a range where the polyamic acid to be purified does not precipitate. The total amount is preferably 80% by weight or less, and more preferably 50% by weight or less.
As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid was purified. You may use for preparation of a liquid crystal aligning agent. Polyamic acid can be isolated by pouring the reaction solution into a large amount of poor solvent to obtain a precipitate, and drying the precipitate under reduced pressure, or by distilling the reaction solution under reduced pressure using an evaporator. it can. Further, the polyamic acid can be purified by a method of dissolving the polyamic acid again in an organic solvent and then precipitating with a poor solvent, or a method of performing the step of distilling under reduced pressure with an evaporator once or several times.

[Polyimide]
The polyimide can be obtained by dehydrating and ring-closing the polyamic acid as described above to imidize. At this time, all of the amic acid units of the polyamic acid may be dehydrated and cyclized, or only a part of the amic acid unit may be dehydrated and cyclized to form a partially imidized product in which the amic acid unit and the imide ring coexist. The imidation ratio of the polyimide is preferably 80% or more, and more preferably 85% or more. Here, the “imidization rate” is a percentage of the number of imide ring units relative to the total number of amic acid units and imide ring units in the polymer. At this time, a part of the imide ring may be an isoimide ring. This imidation ratio is calculated from the following formula (1) from a ¹ H-NMR spectrum obtained by dissolving polyimide in an appropriate solvent and measuring tetramethylsilane as a reference material at room temperature.
Imidization rate (%) = (1-A ¹ / A ² × α) × 100 (1)
(In Formula (1), A ¹ is a peak area derived from protons of NH groups appearing near a chemical shift of 10 ppm, A ² is a peak area derived from other protons, and α is a polyimide precursor (polyamic acid). This is the ratio of the number of other protons to one proton of the NH group in FIG.
Can be calculated.

The dehydration ring closure reaction of the polyamic acid can be carried out by (i) heating the polyamic acid or (ii) dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring closure catalyst to this solution, and heating as necessary. It is done by the method to do.
The reaction temperature in the method of heating the polyamic acid (i) is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. When the reaction temperature is less than 50 ° C., the dehydration ring-closing reaction does not proceed sufficiently, and when the reaction temperature exceeds 200 ° C., the molecular weight of the resulting polyimide may decrease.
On the other hand, in the method (ii) of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride is used as the dehydrating agent. Can do. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of amic acid units which a polyamic acid has. Moreover, as a dehydration ring closure catalyst, tertiary amines, such as a pyridine, a collidine, a lutidine, a triethylamine, can be used, for example. However, it is not limited to these. The amount of the dehydration ring closure catalyst used is preferably 0.01 to 10 moles per mole of the dehydrating agent used. In addition, as an organic solvent used for dehydration ring closure reaction, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid can be mentioned. The reaction temperature of the dehydration cyclization reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C, and the reaction time is preferably 1 to 48 hours, more preferably 2 to 10 hours.

  The polyimide obtained in the above method (i) may be used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after purifying the obtained polyimide. On the other hand, in the method (ii), a reaction solution containing polyimide is obtained as described above. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution. It may be used for the preparation of a liquid crystal aligning agent or may be used for the preparation of a liquid crystal aligning agent after purifying the isolated polyimide. In order to remove the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, for example, a method such as solvent replacement can be applied. The isolation and purification of the polyimide can be performed by performing the same operation as described above as the isolation and purification method of the polyamic acid.

-End-modified polyamic acid and polyimide-
The polyamic acid and the polyimide may be of a terminal modified type whose molecular weight is adjusted. Such a terminal-modified type can be synthesized by adding an appropriate molecular weight regulator such as acid monoanhydride, monoamine compound, monoisocyanate compound to the reaction system when synthesizing the polyamic acid. Here, examples of the acid monoanhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic anhydride. , N-hexadecyl succinic anhydride and the like. Examples of monoamine compounds include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, and n-undecyl. Amine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine, etc. be able to. Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.
When the molecular weight regulator as described above is used in the synthesis of the polyamic acid, the amount used is preferably 10 parts by weight or less, more preferably 5 parts by weight or less with respect to 100 parts by weight of the diamine.

-Solution viscosity of polyamic acid and polyimide-
The polyamic acid is a 10% by weight N-methyl-2-pyrrolidone solution, and the solution viscosity measured at 25 ° C. using an E-type rotational viscometer is preferably 20 to 800 mPa · s, and preferably 30 to 500 mPa · s. More preferably, it is s.
The polyimide is a 10% by weight γ-butyrolactone solution, and the solution viscosity measured at 25 ° C. using an E-type rotational viscometer is preferably 20 to 800 mPa · s, and preferably 30 to 500 mPa · s. More preferred .

Good preferable proportion of at least one polymer selected from the group consisting of radiation-sensitive polysiloxane and polyamic acid and polyimide in the liquid crystal aligning agent of the present invention, a polyamic acid and for radiation sensitive polysiloxane 100 parts by weight a 100 to 5,000 parts by weight as the total weight of the polyimide, has preferably to be more 200 to 2,000 parts by weight.

[Heat-sensitive crosslinking agent]
The heat-sensitive crosslinking agent can be used for stabilizing the pretilt angle and improving the coating film strength. A polyfunctional epoxy compound is effective as the heat-sensitive crosslinking agent. For example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl. Glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetra Glycidyl-4,4′-diaminodiphenylmethane, N, N-diglycidylbenzylamine, N, N-diglycidylaminomethylcyclohexane, bisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolak type epoxy resin, cycloaliphatic An epoxy resin, a glycidyl ester epoxy resin, a glycidyl diamine epoxy resin, a heterocyclic epoxy resin, an acrylic resin having an epoxy group, or the like can be used. As these commercially available products, for example, Epolite 400E, 3002 (above, manufactured by Kyoeisha Chemical Co., Ltd.), Epicoat 828, 152, Epoxy Novolak 180S (above, made by Japan Epoxy Resin Co., Ltd.) and the like are preferable. be able to. When a polyfunctional epoxy compound is used as a heat-sensitive crosslinking agent, a base catalyst such as 1-benzyl-2-methylimidazole may be used in combination for the purpose of efficiently causing a crosslinking reaction.
When the liquid crystal aligning agent of the present invention contains a heat-sensitive crosslinking agent, the content ratio thereof is 100 parts by weight in total with the above-mentioned radiation-sensitive polysiloxane and other polymers optionally used. Preferably it is 100 weight part or less, More preferably, it is 50 weight part or less.

[Functional silane compounds]
The said functional silane compound can be used in order to improve the adhesiveness with the board | substrate of the liquid crystal aligning film obtained. Examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, and N- (2-aminoethyl) -3. -Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltri Methoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7 Triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl- 3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene ) -3-Aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane can and the like, especially open to further 63 is described in over 291,922 No. Gazette, and the like reaction product of a silane compound having a tetracarboxylic dianhydride and an amino group.
When the liquid crystal aligning agent of the present invention contains a functional silane compound, the content ratio is based on 100 parts by weight of the total of the radiation-sensitive polysiloxane and other polymers optionally used. Preferably it is 50 weight part or less, More preferably, it is 20 weight part or less.

[Surfactant]
Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, silicone surfactants, polyalkylene oxide surfactants, and fluorine-containing surfactants. Can be mentioned.
When the liquid crystal aligning agent of this invention contains surfactant, as the content rate, Preferably it is 10 weight part or less with respect to 100 weight part of the whole liquid crystal aligning agent, More preferably, it is 1 weight part or less. is there.

[Preparation of liquid crystal aligning agent]
The liquid crystal aligning agent of the present invention, good Mashiku each component is prepared as a solution form of the composition dissolved in an organic solvent.
As the organic solvent which can be used to prepare the liquid crystal aligning agent of the present invention, to dissolve the radiation-sensitive polysiloxane and optionally used other components, not the preferred one which does not react with these.
Preferred organic solvents definitive for the liquid crystal aligning agent of the present invention include organic solvents exemplified above as those used in the synthesis of the polyamic acid. At this time, you may use together the poor solvent illustrated as what is used for the synthesis | combination of the polyamic acid of this invention.

Particularly preferred organic solvents include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, diisobutyl ketone, 4-hydroxy-4-methyl-2- Pentanone, diisopentyl ether, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, isoamyl propionate, isoamyl isobutyrate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl Ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, Examples include ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, and diethylene glycol monoethyl ether acetate.
These organic solvents, Ru can be used alone or in combination of two or more.

Preferred organic solvents used in the preparation of liquid crystal aligning agent of the present invention, which is obtained by combining one or more of the organic solvents noted above, contained in the liquid crystal alignment agent in the preferred solid concentration of the following Each component to be deposited does not precipitate, and the surface tension of the liquid crystal aligning agent is in the range of 25 to 40 mN / m.
The solid content concentration of the liquid crystal aligning agent of the present invention, that is, the ratio of the weight of all components other than the solvent in the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent is selected in consideration of viscosity, volatility, Preferably it is the range of 1-10 weight%. The liquid crystal aligning agent of the present invention is applied to the substrate surface to form a coating film that becomes a liquid crystal alignment film. When the solid content concentration is less than 1% by weight, the film thickness of this coating film becomes too small. In some cases, it is difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, it is difficult to obtain a good liquid crystal alignment film due to excessive film thickness, and the viscosity of the liquid crystal alignment agent increases, resulting in insufficient coating characteristics. There is a case. The particularly preferable range of the solid content concentration of the liquid crystal aligning agent of the present invention varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when the spinner method is used, the solid content concentration is particularly preferably in the range of 1.5 to 4.5% by weight. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s.
The temperature for preparing the liquid crystal aligning agent of the present invention is preferably 0 ° C. to 200 ° C., more preferably 20 ° C. to 60 ° C.

<Method for forming liquid crystal alignment film>
The liquid crystal aligning agent of this invention can be used conveniently in order to form a liquid crystal aligning film by the photo-alignment method.
As a method for forming the liquid crystal alignment film, for example, a method of forming a coating film of the liquid crystal alignment film of the present invention on a substrate and then imparting liquid crystal alignment ability to the coating film by a photo-alignment method can be mentioned.
First, the liquid crystal aligning agent of the present invention is applied to the transparent conductive film side of the substrate provided with the patterned transparent conductive film by an appropriate application method such as a roll coater method, a spinner method, a printing method, an inkjet method, or the like. For example, the coating film is formed by heating at a temperature of 40 to 250 ° C. for 0.1 to 120 minutes. The thickness of the coating film is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm, as the thickness after removal of the solvent.
Examples of the substrate include glass such as float glass and soda glass, and a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly (cycloaliphatic olefin).
As the transparent conductive film, a NESA film made of SnO _{2 or} an ITO film made of In ₂ O ₃ —SnO ₂ can be used. For patterning these transparent conductive films, a photo-etching method or a method using a mask when forming the transparent conductive film is used.
When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate or the transparent conductive film and the coating film, a functional silane compound, titanate compound or the like is previously applied on the substrate and the transparent conductive film. May be.

Next, the coating film is irradiated with linearly polarized light, partially polarized radiation or non-polarized radiation, and optionally subjected to a heat treatment at a temperature of 150 to 250 ° C., preferably for 1 to 120 minutes, thereby improving the liquid crystal alignment ability. To give a liquid crystal alignment film. Here, as radiation, for example, ultraviolet rays and visible light containing light having a wavelength of 150 to 800 nm can be used, but ultraviolet rays containing light having a wavelength of 300 to 400 nm are preferable. When the radiation used is linearly polarized or partially polarized, irradiation may be performed from a direction perpendicular to the substrate surface, or from an oblique direction to give a pretilt angle, or a combination thereof. May be. When irradiating non-polarized radiation, the direction of irradiation needs to be an oblique direction.
As a light source to be used, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, or the like can be used. The ultraviolet rays in the preferable wavelength region can be obtained by means of using the light source in combination with, for example, a filter or a diffraction grating.
The irradiation dose of radiation, preferably less than 1 J / ^{m 2} or more 10,000 J / ^{m 2,} more preferably from 10~3,000J / ^{m 2.} In addition, when providing the liquid crystal aligning ability by the photo-alignment method to the coating film formed from the conventionally known liquid crystal aligning agent, the irradiation dose of 10,000 J / m < ² > or more was required. However, when the liquid crystal aligning agent of the present invention is used, good liquid crystal alignment is imparted even when the radiation irradiation amount in the photo-alignment method is 3,000 J / m ² or less, and further 1,000 J / m ² or less. This contributes to a reduction in the manufacturing cost of the liquid crystal display element.
The “pretilt angle” in the present invention represents an angle of inclination of liquid crystal molecules from a direction parallel to the substrate surface.

<Manufacturing method of liquid crystal display element>
The liquid crystal display element of this invention comprises the liquid crystal aligning film formed from the liquid crystal aligning agent of this invention. The liquid crystal display element of this invention can be manufactured as follows, for example.
A pair of (two) substrates on which the liquid crystal alignment film is formed as described above is prepared, and these liquid crystal alignment films are opposed so that the polarization direction of the irradiated linearly polarized radiation becomes a predetermined angle. A liquid crystal cell is constructed by sealing the peripheral part between them with a sealant, injecting and filling liquid crystal, and sealing the liquid crystal injection port. Next, it is desirable that the liquid crystal cell is heated to a temperature at which the liquid crystal used has an isotropic phase and then cooled to room temperature to remove the flow alignment during injection.
Then, a polarizing plate is bonded to both surfaces so that the polarization direction forms a predetermined angle with the alignment easy axis of the liquid crystal alignment film of the substrate, thereby obtaining a liquid crystal display element. When the liquid crystal alignment film is horizontally aligned, by adjusting the angle formed by the polarization direction of the irradiated linearly polarized radiation and the angle between each substrate and the polarizing plate in the two substrates on which the liquid crystal alignment film is formed A liquid crystal display element having a TN type or STN type liquid crystal cell can be obtained. On the other hand, in the case where the liquid crystal alignment film is vertically aligned, the cell is configured so that the directions of easy alignment axes in the two substrates on which the liquid crystal alignment film is formed are parallel, A liquid crystal display element having a vertical alignment type liquid crystal cell can be obtained by bonding so that the polarization direction forms an angle of 45 ° with the easy alignment axis.
As the sealing agent, for example, an aluminum oxide sphere as a spacer and an epoxy resin containing a curing agent can be used.
As the liquid crystal, for example, a nematic liquid crystal, a smectic liquid crystal, or the like can be used. In the case of a TN type liquid crystal cell or STN type liquid crystal cell, a nematic type liquid crystal having positive dielectric anisotropy is preferable. For example, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, an ester liquid crystal, a terphenyl liquid crystal, a biphenylcyclohexane liquid crystal, Pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like are used. Further, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonate, cholesteryl carbonate, etc .; chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck & Co., Inc.). A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate can be further added and used.

On the other hand, in the case of a vertical alignment type liquid crystal cell, a nematic type liquid crystal having negative dielectric anisotropy is preferable. For example, dicyanobenzene liquid crystal, pyridazine liquid crystal, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenyl cyclohexane. System liquid crystal or the like is used.
The polarizing plate used outside the liquid crystal cell is composed of a polarizing film called a “H film” in which iodine is absorbed while stretching and orientation of polyvinyl alcohol is sandwiched between cellulose acetate protective films, or the H film itself. A polarizing plate etc. can be mentioned.
The liquid crystal display element of the present invention thus produced is excellent in various performances such as display characteristics and reliability.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
The weight average molecular weight in the following examples is a polystyrene equivalent value measured by gel permeation chromatography under the following conditions.
Column: “TSKgelGRCXLII” manufactured by Tosoh Corporation
Solvent: Tetrahydrofuran Temperature: 40 ° C
Pressure: 68 kgf / cm ²

<Synthesis of cinnamic acid derivatives>
Synthesis example P (1)
Scheme 1 below

Thus, compound (2-P4-1) was synthesized.
A 1 L eggplant-shaped flask was charged with 91.3 g of methyl 4-hydroxybenzoate, 182.4 g of potassium carbonate, and 320 mL of N-methyl-2-pyrrolidone, stirred at room temperature for 1 hour, and then charged with 99. 1-bromopentane. 7 g was added and reacted at 100 ° C. for 5 hours with stirring. After completion of the reaction, reprecipitation was performed with water. Next, 48 g of sodium hydroxide and 400 mL of water were added to the precipitate and refluxed for 3 hours to carry out a hydrolysis reaction. After completion of the reaction, the reaction mixture was neutralized with hydrochloric acid, and the resulting precipitate was recrystallized from ethanol to obtain 104 g of white crystals of the compound (2-P4-1-1).
104 g of this compound (2-P4-1-1) was placed in a reaction vessel, 1 L of thionyl chloride and 770 μL of N, N-dimethylformamide were added thereto, and the mixture was stirred at 80 ° C. for 1 hour. Next, thionyl chloride was distilled off under reduced pressure, methylene chloride was added, washed with an aqueous sodium hydrogen carbonate solution, dried over magnesium sulfate, concentrated, and then tetrahydrofuran was added to form a solution.

Next, 74 g of 4-hydroxycinnamic acid, 138 g of potassium carbonate, 4.8 g of tetrabutylammonium, 500 mL of tetrahydrofuran, and 1 L of water were charged into a 5 L three-necked flask different from the above. This aqueous solution was ice-cooled, a tetrahydrofuran solution containing a reaction product of the above compound (2-P4-1-1) and thionyl chloride was slowly added dropwise, and the reaction was further performed with stirring for 2 hours. After completion of the reaction, the reaction mixture was neutralized with hydrochloric acid, extracted with ethyl acetate, the extract was dried over magnesium sulfate, concentrated, and recrystallized with ethanol to give compound (2-P4 90 g of white crystals of -1-2) were obtained.
In a 300 mL three-necked flask equipped with a stirrer, a nitrogen inlet tube and a thermometer, 42.3 g of the compound (2-P4-1-2) synthesized above, 41.5 g of potassium carbonate, 5.00 g of potassium iodide, 4 -22.3 g of bromo-1-butene and 600 mL of 1-methyl-2-pyrrolidone were charged, and the reaction was performed with stirring at 90 ° C. for 3 hours under nitrogen. After completion of the reaction, toluene and water were added for extraction, and the organic layer was dried over magnesium sulfate, concentrated, and recrystallized from methanol to obtain 35 g of compound (2-P4-1).

Synthesis example P (2)
Scheme 2 below

The compound (3-P5-1) was synthesized according to
A 5 L three-necked flask equipped with a thermometer and a nitrogen inlet tube was charged with 44 g of 4-iodophenol, 32 g of hexyl acrylate, 28 mL of triethylamine, 4.6 g of tetrakistriphenylphosphine palladium, and 2 L of N, N-dimethylformamide, Dried. Subsequently, the system was heated to 90 ° C. and reacted under stirring for 2 hours under a nitrogen stream. After completion of the reaction, dilute hydrochloric acid is added, and the organic layer obtained by extraction with ethyl acetate is washed with water, dried over magnesium sulfate, concentrated and recrystallized from ethanol to give compound (3-P5-1-1). ) 24g was obtained.
In a 500 mL three-necked flask equipped with a thermometer, a nitrogen inlet tube and a reflux tube, 24 g of the compound (3-P5-1-1) synthesized above, 11.0 g of succinic anhydride and 1.2 g of 4-dimethylaminopyridine The system was fully dried. To this system, 11.2 g of triethylamine and 200 mL of tetrahydrofuran were added and reacted under reflux for 5 hours. After completion of the reaction, dilute hydrochloric acid is added, and the organic layer obtained by extraction with ethyl acetate is washed with water, dried over magnesium sulfate, concentrated and recrystallized with ethanol to give compound (3-P5-1-2). 17.4g was obtained.
In a 300 mL three-necked flask equipped with a stirrer, a nitrogen inlet tube and a thermometer, 10.4 g of the compound (3-P5-1-2) synthesized above, 10.4 g of potassium carbonate, 1.25 g of potassium iodide, 4 -5.51 g of butyl-1-butene and 150 mL of 1-methyl-2-pyrrolidone were charged, and the reaction was carried out under stirring at 90 ° C for 3 hours under nitrogen. After completion of the reaction, toluene and water were added for extraction, and the organic layer was dried over magnesium sulfate, concentrated, and recrystallized from methanol to obtain 8.5 g of compound (3-P5-1).

Synthesis example P (3)
The same procedure as in Synthesis Example P (1) except that 20.0 g of allyl bromide was used instead of 4-bromo-1-butene in Synthesis Example P (1). 2)

(Compound (2-P4-2)) was obtained.

[ Synthesis of polyamic acid]
Synthesis example PA-1
196 g (1.0 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 212 g (1, .2) of 2,2′-dimethyl-4,4′-diaminobiphenyl as diamine. 0 mol) was dissolved in 4,050 g of N-methyl-2-pyrrolidone and reacted at 40 ° C. for 3 hours to obtain 3,700 g of a solution containing 10% by weight of polyamic acid (PA-1). The solution viscosity of this polyamic acid solution was 170 mPa · s.
Synthesis example PA-2
22.4 g (0.1 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride and 14.23 g (0.1 mol) of cyclohexanebis (methylamine) were added to 299.3 g of N-methyl-2-pyrrolidone. And reacted at 60 ° C. for 6 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The precipitate was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours to obtain 32 g of polyamic acid PA-2.
[Synthesis of other polysiloxanes]
Synthesis example PS-1
A 200 mL three-necked flask equipped with a condenser was charged with 20.8 g of tetraethoxysilane and 28.2 g of 1-ethoxy-2-propanol, heated to 60 ° C. and stirred. A maleic anhydride aqueous solution prepared by dissolving 0.26 g of maleic anhydride in 10.8 g of water prepared in another flask having a capacity of 20 mL was added thereto, and the reaction was performed by heating and stirring at 60 ° C. for further 4 hours. The solvent was distilled off from the resulting reaction mixture, 1-ethoxy-2-propanol was added, and the mixture was concentrated again to obtain a polymer solution containing 10% by weight of polyorganosiloxane PS-1. The weight average molecular weight Mw of PS-1 was 5,100.

<Synthesis of radiation-sensitive polysiloxane>
Example CH-1
Octakis (hydridosilsesquioxane) (manufactured by TAL MATERIALS Inc.) 0.85 g, 8.97 g of compound (2-P4-1) synthesized in Synthesis Example P (1) above, 80 mL of toluene and platinum-divinyltetramethyldi 100 μL of a xylene solution containing 2% by weight of a siloxane complex was added, and the reaction was performed under reflux for 20 hours under nitrogen. After completion of the reaction, reprecipitation with methanol, the precipitate was dissolved in ethyl acetate and washed with water, and then the solvent was distilled off to obtain 5.4 g of a white powder of radiation-sensitive polysiloxane S-CH-1. .
Example CH-2
In the above Example CH-1, the above procedure was performed except that instead of 8.97 g of the compound (2-P4-1), a mixture of 4.49 g of the compound (2-P4-1) and 1.14 g of allyl glycidyl ether was used. It carried out like Example CH-1 and obtained radiation sensitive polysiloxane S-CH-2.
Example CH-3
In Example CH-1, except that 8.97 g of compound (2-P4-1) was used, 8.05 g of compound (3-P5-1) synthesized in Synthesis Example P (2) was used. Example CH-1 was carried out in the same manner to obtain radiation-sensitive polysiloxane S-CH-3.
Example CH-4
The above Example CH-1 except that 8.66 g of the compound (2-P4-2) synthesized in the above Synthesis Example P (3) was used instead of the compound (2-P4-1) in the above Example CH-1. In the same manner as in -1, radiation-sensitive polyorganosiloxane S-CH-4 was obtained.

<Preparation of liquid crystal aligning agent and evaluation of storage stability>
Example CH-5
[Preparation of liquid crystal aligning agent]
PA of a solution containing 100 parts by weight of the radiation-sensitive polysiloxane S-CH-1 obtained in Example CH-1 and the polyamic acid PA-1 obtained in Synthesis Example PA-1 as another polymer -1 is converted to 2,000 parts by weight, N-methyl-2-pyrrolidone and butyl cellosolve are added, and the solvent composition is N-methyl-2-pyrrolidone: butyl cellosolve = 50: 50 ( (Weight ratio) and a solid content concentration of 3.0% by weight.
The solution was filtered through a filter having a pore size of 1 μm to prepare a liquid crystal aligning agent A-CH-1.
When the storage stability of this liquid crystal aligning agent A-CH-1 was evaluated by the following method and criteria, the storage stability of the liquid crystal aligning agent A-CH-1 was “good”.

[Method for evaluating storage stability]
A coating film of a liquid crystal aligning agent was formed on a glass substrate by a spin coating method with the number of revolutions as a variable, and the number of revolutions at which the film thickness of the coating film after removal of the solvent was 1,000 mm was examined.
Next, a part of the liquid crystal aligning agent A-CH-1 was taken and stored at -15 ° C for 5 weeks. The liquid crystal aligning agent after storage was visually observed, and when insoluble precipitates were observed, it was determined that the storage stability was “bad”.
If insoluble matter was not observed after storage for 5 weeks, a coating film was further formed on the glass substrate by spin coating with a rotational speed of 1,000 mm before storage, and after removal of the solvent The film thickness was measured. When the film thickness deviated from 1,000 mm by 10% or more, the storage stability was judged as “bad”, and when the film thickness deviation was less than 10%, the storage stability was judged as “good”. .
In addition, the measurement of the film thickness of the said coating film was performed using the stylus-type level | step difference film thickness meter by KLA-Tencor.

Examples CH-6 to 10, 15, 16, and 18
Liquid crystal aligning agents A-CH-2 to A-CH-6 and the same as in Example CH-5 except that the type of radiation-sensitive polysiloxane and the type and amount of polyamic acid were as shown in Table 1. A-CH-11, A-CH-12 and A-CH-14 were prepared respectively.
Reference example CH-11
Taking an amount corresponding to PS-1 solids 2,000 parts by weight of the solution containing another polysiloxane PS-1 obtained above Symbol Synthesis Example 5, sensitive radiation this obtained in Example CH-1 100 parts by weight of functional polysiloxane S-CH-1 was added, and 1-ethoxy-2-propanol was further added to obtain a solution having a solid content concentration of 4.0% by weight.
The solution was filtered through a filter having a pore size of 1 μm to prepare a liquid crystal aligning agent A-CH-7.
Reference examples CH-12 to 14 and 17
The liquid crystal aligning agents A-CH-8 to A-CH- were the same as in Reference Example CH-11 except that the types of radiation-sensitive polysiloxanes and the types and amounts of other polysiloxanes were as shown in Table 1. 10 and A-CH-13 were prepared respectively.

Example CH-19
<Manufacture of vertical alignment type liquid crystal display element>
On the transparent electrode surface of the glass substrate with a transparent electrode made of an ITO film, the liquid crystal aligning agent A-CH-1 prepared in the above Example CH-5 was applied using a spinner, and then on a hot plate at 80 ° C. for 1 minute. After pre-baking, it was heated at 200 ° C. for 1 hour in an oven in which the inside of the cabinet was replaced with nitrogen to form a coating film having a thickness of 0.1 μm. Next, the surface of the coating film was irradiated with polarized ultraviolet rays of 1,000 J / m ² containing a 313 nm emission line from a direction inclined by 40 ° from the normal to the liquid crystal alignment film using a Hg-Xe lamp and a Grand Taylor prism. did. The same operation was repeated to prepare a pair (two) of substrates having a liquid crystal alignment film.
After applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm to the outer periphery of the surface of the substrate having one liquid crystal alignment film by screen printing, the liquid crystal alignment film surfaces of the pair of substrates are made to face each other, The adhesive was pressure-bonded so that the projection direction of the optical axis of the ultraviolet rays of each substrate onto the substrate surface was antiparallel, and the adhesive was thermally cured at 150 ° C. for 1 hour. Next, after filling the gap between the substrates from the liquid crystal injection port with negative type liquid crystal (MLC-6608 manufactured by Merck), the liquid crystal injection port was sealed with an epoxy adhesive. Furthermore, in order to remove the flow alignment at the time of liquid crystal injection, this was heated at 150 ° C. and then gradually cooled to room temperature. Next, the polarizing plates are bonded to both outer surfaces of the substrate so that the polarization directions thereof are orthogonal to each other and form an angle of 45 ° with the projection direction of the optical axis of the liquid crystal alignment film onto the substrate surface. A vertical liquid crystal display element was manufactured.
This liquid crystal display element was evaluated by the following method. The evaluation results are shown in Table 2.

<Evaluation method of liquid crystal display element>
(1) Evaluation of liquid crystal orientation With respect to the liquid crystal display element manufactured above, the presence or absence of abnormal domains in the change in brightness when a voltage of 5 V is turned ON / OFF (applied / released) is observed with a microscope. The case was defined as “good”.
(2) Evaluation of pretilt angle The liquid crystal display device manufactured as described above was subjected to T.W. J. et al. Scheffer et. al. J. et al. Appl. Phys. vol. 19, p2013 (1980), the pretilt angle was measured by a crystal rotation method using He—Ne laser light.
(3) Evaluation of voltage holding ratio After applying a voltage of 5 V to the liquid crystal display element manufactured above with an application time of 60 microseconds and a span of 167 milliseconds, the voltage holding ratio after 167 milliseconds from the release of application is obtained. It was measured. As a measuring device, “VHR-1” manufactured by Toyo Corporation was used.
(4) Evaluation of burn-in The liquid crystal display element manufactured above was applied with a 30 Hz, 3 V rectangular wave superimposed with a direct current of 5 V at an ambient temperature of 60 ° C. for 2 hours, and remained in the liquid crystal cell immediately after the DC voltage was turned off. The residual DC voltage was determined by the flicker elimination method.

Examples CH-20 to 32 and Reference Example CH-33
Vertical alignment type liquid crystal display element in the same manner as in Example CH-19 except that the type of liquid crystal alignment agent used and the irradiation amount of polarized ultraviolet rays at the time of forming the liquid crystal alignment film were as shown in Table 2. Were manufactured and evaluated. The results are shown in Table 2.
Further, in Reference Example CH- 33, when the light resistance was evaluated as follows, the evaluation result was “good”.
[Evaluation of light resistance in Reference Example CH-33]
With respect to the liquid crystal display device manufactured as described above, the initial voltage holding ratio was measured under the same conditions as the evaluation of the voltage holding ratio. Thereafter, the liquid crystal display element was placed at a distance of 5 cm under a 40-watt white fluorescent lamp, irradiated with light for 1,000 hours, and then the voltage holding ratio was measured again under the same conditions as described above. When the voltage holding ratio was less than ± 2% compared to the initial value, the light resistance was evaluated as “good”, and when it was ± 2% or higher, the light resistance was evaluated as “bad”.
Comparative example CH-1
<Synthesis of polyamic acid>
The following formula (d-1) synthesized according to 22.4 g (0.1 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride and JP-T-2003-520878

48.46 g (0.1 mol) of the compound represented by the formula was dissolved in 283.4 g of N-methyl-2-pyrrolidone and reacted at room temperature for 6 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The precipitate was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours to obtain 67 g of polyamic acid.

<Preparation of liquid crystal aligning agent>
The polyamic acid synthesized above was dissolved in a mixed solvent composed of N-methyl-2-pyrrolidone and butyl cellosolve (mixing ratio = 50: 50 (weight ratio)) to obtain a solution having a solid content concentration of 3.0% by weight. The solution was filtered through a filter having a pore size of 1 μm to prepare a liquid crystal aligning agent R—CH-1.
<Manufacture and evaluation of vertical alignment type liquid crystal display element>
A liquid crystal alignment film was formed in the same manner as in Example CH-19 except that the liquid crystal aligning agent R-CH-1 prepared above was used, and a vertical alignment type liquid crystal display device was manufactured and evaluated. The results are shown in Table 2.

Reference example CH-34
<Manufacture of TN alignment type liquid crystal display element>
The liquid crystal aligning agent A-CH-11 prepared in Example CH-15 was applied on the transparent electrode surface of the glass substrate with a transparent electrode made of an ITO film using a spinner, and then on a hot plate at 80 ° C. for 1 minute. After pre-baking, a coating film having a thickness of 0.1 μm was formed by heating at 200 ° C. for 1 hour. By using a Hg-Xe lamp and a Grand Taylor prism, the surface of this coating film was irradiated with polarized ultraviolet rays of 1,000 J / m ² containing a 313 nm emission line from a direction inclined by 40 ° from the substrate normal, thereby aligning the liquid crystal. A liquid crystal alignment film was formed by imparting performance.
The same operation as described above was repeated to prepare a pair (two) of glass substrates having a liquid crystal alignment film on the transparent conductive film surface.
An epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is applied to the peripheral portions of the surfaces of the pair of substrates on which the liquid crystal alignment film is formed by screen printing, so that the polarized ultraviolet irradiation directions are orthogonal to each other. The substrate was superposed and pressure-bonded, and the adhesive was thermally cured by heating at 150 ° C. for 1 hour. Next, a positive nematic liquid crystal (Merck, MLC-6221, containing a chiral agent) was injected and filled into the gap between the substrates through the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Furthermore, in order to remove the flow alignment at the time of liquid crystal injection, this was heated at 150 ° C. for 10 minutes and then gradually cooled to room temperature. Next, a TN liquid crystal display element was manufactured by bonding the polarizing plates on both outer surfaces of the substrate so that the polarization directions thereof were orthogonal to each other and parallel to the polarization direction of the liquid crystal alignment film.
The liquid crystal display element was evaluated for liquid crystal orientation, voltage holding ratio, and image sticking in the same manner as in Example CH-19. The results are shown in Table 3.
Reference examples CH-35 and 36
A TN alignment type liquid crystal display device was produced and evaluated in the same manner as in Reference Example CH-34 except that the type of liquid crystal alignment agent used was as described in Table 3. The results are shown in Table 3.

As specifically shown by the above examples, the liquid crystal aligning agent of the present invention is not only excellent in storage stability but also less radiation compared to conventionally known liquid crystal aligning agents for photo-alignment. Depending on the irradiation amount, a liquid crystal alignment film having excellent liquid crystal alignment properties and electrical characteristics can be formed.

Claims (5)

Following formula (1)

(In Formula (1), ^{Y 1} represents a hydroxyl group, an alkoxyl group having 1 to 10 carbon atoms, an alkyl group or an aryl group having 6 to 20 carbon atoms having 1 to 20 carbon atoms.)
At least one selected from the group consisting of a polysiloxane having a repeating unit represented by the formula:
Radiation sensitive polysiloxane obtained by reacting a cinnamic acid derivative having at least one group selected from the group consisting of alkenyl and alkynyl groups, and at least one selected from the group consisting of polyamic acid and polyimide Liquid crystal aligning agent characterized by containing the polymer of these. The cinnamic acid derivative is at least one group selected from the group consisting of an alkenyl group and an alkynyl group;

The liquid crystal aligning agent of Claim 1 which is a compound which has a bivalent group represented by these. The cinnamic acid derivative is represented by the following formula (2):

(In Formula (2), R ¹ is a C1-C40 monovalent organic group containing a C1-C40 alkyl group or an alicyclic group, provided that a part of hydrogen atoms of the alkyl group or All may be substituted with fluorine atoms, R ² is a single bond, an oxygen atom, —COO— or —OCO—, R ³ is a divalent aromatic group, a divalent alicyclic group, 2 R ⁴ is a monovalent heterocyclic group or a divalent fused cyclic group, and R ⁴ is a single bond, an oxygen atom, ^* —COO— or ^* —OCO— (where the bond marked with “*” is R ³ and R ⁵ is a single bond, a methylene group or an alkylene group having 2 to 10 carbon atoms, and when R ⁵ is a single bond, R ⁶ is —CH═CH ₂ or —C≡CH, When R ⁵ is a methylene group or an alkylene group, R ⁶ is —CH═CH ₂ , —C≡CH or —OOC—C H = CH ₂ , R ⁷ is a fluorine atom or a cyano group, X ¹ is an oxygen atom or the following formula

(However, the bond marked with “*” is on the R ⁵ -R ⁶ side.)
A is an integer of 0 to 3, and b is an integer of 0 to 4. )
Or a compound represented by the following formula (3)

(In the formula (3), R ⁸ is a monovalent organic group having 3 to 40 carbon atoms containing an alkyl group or an alicyclic group having 1 to 40 carbon atoms, provided that a portion of the hydrogen atoms of the alkyl group or All may be substituted with fluorine atoms, R ⁹ is an oxygen atom, —COO— or —OCO—, and R ¹⁰ is a divalent aromatic group, a divalent heterocyclic group or a divalent condensed group. A cyclic group, R ¹¹ is a single bond, —OCO— (CH ₂ ) _e — ^* or —O— (CH ₂ ) _g — ^* (where a bond marked with “*” binds to R ¹² . E) and g are each an integer of 0 to 10, R ¹² is —CH═CH ₂ , —C≡CH or —OOC—CH═CH ₂ , and R ¹³ is a fluorine atom or cyano. X ² is an oxygen atom, a phenylene group or the following formula

(However, the bond marked with “*” binds to R ^8. )
C is an integer of 0 to 3, and d is an integer of 0 to 4. )
The liquid crystal aligning agent of Claim 2 which is a compound represented by these.   A method for forming a liquid crystal alignment film, comprising: applying a liquid crystal aligning agent according to any one of claims 1 to 3 on a substrate to form a coating film; and irradiating the coating film with radiation. .   A liquid crystal display element comprising a liquid crystal alignment film formed from the liquid crystal aligning agent according to claim 1.