TW202036125A - Method for producing liquid crystal alignment film, liquid crystal alignment film, and liquid crystal display element - Google Patents

Abstract

The present invention provides a method for easily producing a VA mode liquid crystal display element having excellent viewing angle characteristics, said liquid crystal display element being provided with a plurality of domains having different alignment directions (multi-domain). The present invention is a method for producing a multi-domain liquid crystal alignment film, which sequentially comprises in the following order: a step for forming a cured film by applying a liquid crystal aligning agent onto a substrate, said liquid crystal aligning agent containing a solvent and a polymer that has a photo-alignment group and a thermally crosslinkable group A (component (A)) and satisfying at least one of the requirements Z1 and Z2 described below; a first irradiation step for irradiating the cured film with ultraviolet light from an oblique direction; and a second irradiation step for irradiating the cured film after the first ultraviolet irradiation with ultraviolet light from a direction that is different from the direction of the first irradiation step. This method for producing a multi-domain liquid crystal alignment film is configured such that at least one of the irradiation steps is carried out by the intermediary of a mask which comprises a region where light is blocked and another region where light is not blocked. Z1: The component (A) additionally has a thermally crosslinkable group B. Z2: A compound having a thermally crosslinkable group B is additionally contained as a component (B).

Description

Method for manufacturing liquid crystal alignment film, liquid crystal alignment film and liquid crystal display element

The present invention relates to a method for manufacturing a liquid crystal alignment film using a liquid crystal alignment agent, a liquid crystal alignment film obtained therefrom, and a liquid crystal display element provided with the liquid crystal alignment film obtained. In more detail, by using a specific liquid crystal alignment agent, even if the firing temperature is low and the firing time is short, the liquid crystal alignment is good, and the pretilt angle performance is also excellent, and high reliability At the same time, it can also be used for pre-tilt overwriting liquid crystal alignment film, and using a specific liquid crystal alignment agent to produce a multi-region liquid crystal alignment film with excellent display quality, a multi-region liquid crystal alignment film and a liquid crystal display element.

For liquid crystal display elements, the liquid crystal alignment film plays a role of aligning liquid crystals in a certain direction. Nowadays, the main liquid crystal alignment film used in industry is a polyimide made of polyimide precursors, polyamic acid, polyamic acid ester, or polyimide-containing solution. The amine-based liquid crystal alignment agent is coated on the substrate for film formation. In addition, when the liquid crystal is aligned parallel or obliquely to the substrate surface, the surface is extended by rubbing after film formation.

On the other hand, when the substrate is vertically aligned with liquid crystals (called a vertical alignment (VA) method), a combination of a long-chain alkyl group or a cyclic group or a cyclic group and an alkyl group is used (for example, refer to Patent Document 1), A liquid crystal alignment film in which a hydrophobic group such as a steroid skeleton (for example, refer to Patent Document 2) is introduced into the side chain of the polyimide. At this time, when a voltage is input between the substrates and the liquid crystal molecules are tilted in a parallel direction on the substrate, the liquid crystal molecules must be tilted from the normal direction of the substrate to one of the directions within the surface of the substrate. As a means at this time, for example, a method of providing protrusions on the substrate, a method of providing slits on the display electrode, and rubbing to tilt liquid crystal molecules from the normal direction of the substrate to one of the directions of the substrate surface (to make The method of pre-tilting) further proposes a method in which a photopolymerizable compound is added to the liquid crystal composition in advance, and a vertical alignment film such as polyimide is used at the same time, and the liquid crystal cell is irradiated with ultraviolet rays while inputting a voltage to pre-tilt the liquid crystal (for example, refer to Patent Document 3) and so on.

In recent years, the formation of protrusions or slits in the alignment control of liquid crystals in the VA method has also been proposed, and as a substitute for the PSA technology, a method (photoalignment method) using anisotropic photochemical reactions such as irradiation with polarized ultraviolet rays has been proposed. That is, it is known that for a polyimide film with a photoreactive vertical alignment property, irradiated with polarized ultraviolet rays, and by imparting orientation adjustment ability and pretilt angle performance, the tilt direction of liquid crystal molecules during voltage input can be uniformly controlled ( Refer to Patent Document 4). At this time, as with the conventional alignment film, a polyimide-based liquid crystal alignment film having excellent durability and suitable for controlling the pretilt angle of the liquid crystal is used. The polyimide-based liquid crystal alignment film is fired at a high temperature of 200° C. or higher as a general method.

On the other hand, the review of the use of thin and lightweight plastic substrates for the substrates of liquid crystal display elements has also been vigorously promoted. At this time, since the heat resistance of the plastic substrate is low, the firing during the production of the liquid crystal alignment film must be performed at a relatively low temperature. Similarly, by setting the firing temperature to a low temperature, it is also required to reduce the energy cost in the manufacture of liquid crystal display elements.

When firing at a low temperature, there is a problem that the alignment film material has to be cured in an insufficiently cured state, and it is difficult to obtain a liquid crystal display element with high reliability (for example, refer to Patent Document 5).

On the other hand, although there is an increasing demand for multi-region technology to form a plurality of regions with different alignment directions (alignment division), in the past manufacturing method, after exposure is performed using an exposure mask in which a plurality of openings are arranged at predetermined intervals It is necessary to remove the exposure mask only at a predetermined interval and perform re-exposure. The alignment of the exposure mask or the formation of a plurality of openings requires high precision, which complicates the manufacturing process, so improvement is expected. Among them, although it is known to use a method for manufacturing a multi-domain liquid crystal display element in which a polymer having a vertical alignment group is bonded to a photodecomposable polyimide, it requires a very large amount of light irradiation, which deteriorates the manufacturing efficiency. (For example, refer to Patent Documents 6, 7, and 8). Although there are other examples of the manufacturing method of the multi-domain alignment film, it is not clear what kind of alignment film is used to implement the invention (for example, refer to Patent Document 9). [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. Hei 3-179323 [Patent Document 2] Japanese Patent Publication No. 4-281427 [Patent Document 3] Japanese Patent No. 4504626 [Patent Document 4] Japanese Patent No. 4995267 [Patent Document 5] Japanese Patent Publication No. 7-209633 [Patent Document 6] Japanese Patent Publication No. 11-95224 [Patent Document 7] Japanese Patent Publication No. 2005-148442 [Patent Document 8] Japanese Patent Publication No. 2005-316027 [Patent Document 9] Japanese Patent Publication No. 2007-219191

[Problem Solved by Invention]

The purpose of the present invention is to provide a VA mode liquid crystal display element and a manufacturing method thereof that can form a plurality of regions with different alignment directions (alignment divisions) with less mask processing steps, and has excellent viewing angle characteristics. . In addition, the purpose of the present invention is to provide an ECB liquid crystal display element with improved viewing angle characteristics and a liquid crystal alignment film used in the element. [Means to solve the problem]

The inventors discovered an invention with the following <X> as the gist. <X> A method for manufacturing a multi-domain liquid crystal alignment film, which is characterized by including the following steps: a photo-alignment group represented by the following formula (pa-1) as the component (A) and thermal crosslinkability A step of applying a polymer and solvent based on A, and a liquid crystal alignment agent satisfying at least one of the following requirements Z1 and Z2 on the substrate, and forming a cured film by drying and firing; The first irradiation step of irradiating the cured film with ultraviolet rays from an oblique direction; and For the cured film after the ultraviolet irradiation, the second irradiation step of ultraviolet irradiation is performed from a direction different from the first irradiation step, At least one of the first irradiation step and the second irradiation step is performed through a mask including a light-shielded area and an unshielded area. Z1: The polymer of the component (A) further contains a thermally crosslinkable group B. Z2: It further contains a compound having two or more thermally crosslinkable groups B in the molecule as the component (B).

In the formula, A is represented by a group selected from fluorine, chlorine, cyano, or an alkoxy group with 1 to 5 carbons, linear or branched alkyl residues (this is a Need to be substituted by 1 cyano group or more than 1 halogen atom) substituted pyrimidine-2,5-diyl, pyridine-2,5-diyl, 2,5-thiophene, 2,5-furan , 1,4- or 2,6-naphthylene or phenylene, R ₁ represents a single bond, an oxygen atom, -COO- or -OCO-, R ₂ represents a divalent aromatic group, a divalent alicyclic group, A divalent heterocyclic group or a divalent condensed cyclic group, R ₃ is a single bond, an oxygen atom, -COO- or -OCO-, and R ₄ is a linear or branched alkyl group having 1 to 40 carbons or containing The alicyclic group is a monovalent organic group with 3 to 40 carbons, D represents an oxygen atom, a sulfur atom or -NR _d- (where R _d represents a hydrogen atom or an alkyl group with 1 to 3 carbons), a represents 0 An integer of ~3, * indicates the bonding position. Thermally crosslinkable group A and thermally crosslinkable group B are each independently selected from carboxyl group, amino group, alkoxymethyl amide group, hydroxymethyl amide group, hydroxyl group, epoxy moiety-containing group, oxygen An organic group consisting of a heterocyclobutanyl group, a thiopropanyl group, an isocyanate group, and a blocked isocyanate group, the thermally crosslinkable group A and the thermally crosslinkable group B can be crosslinked by heat However, the thermally crosslinkable group A and the thermally crosslinkable group B may be the same as each other. [Effects of Invention]

According to the present invention, at least the mask processing step can be improved, a plurality of regions with different alignment directions (alignment division) can be more simply formed, and a VA mode liquid crystal display element with excellent viewing angle characteristics can be formed.

[The form of implementing the invention]

The manufacturing method of the multi-domain liquid crystal alignment film of the present invention is characterized in that it contains the following steps: the photo-alignment group represented by the above formula (pa-1) having the component (A) and the thermally crosslinkable group A The step of applying a liquid crystal alignment agent that satisfies at least one of the following requirements Z1 and Z2, and then dried and fired to form a cured film, The first irradiation step of irradiating the cured film with ultraviolet rays from an oblique direction, and For the cured film after the ultraviolet irradiation, the second irradiation step of ultraviolet irradiation is performed from a direction different from the first irradiation step. At least one of the first irradiation step and the second irradiation step is performed through a mask including a light-shielded area and an unshielded area. Z1: The polymer of the component (A) further has a thermally crosslinkable group B. Z2: It further contains a compound having two or more thermally crosslinkable groups B in the molecule as the (B) component. The thermally crosslinkable group A and the thermally crosslinkable group B are each independently selected from a carboxyl group, an amino group, an alkoxymethyl amide group, a hydroxymethyl amide group, a hydroxyl group, an epoxy moiety-containing group, and oxa Cyclobutanyl group, thiopropyl ring group, isocyanate group and blocked isocyanate group are groups of organic groups, the thermally crosslinkable group A and thermally crosslinkable group B can be crosslinked by heat, However, the thermally crosslinkable group A and the thermally crosslinkable group B may be the same as each other.

Among them, the so-called "has more than two in the molecule" means, for example, containing two or more epoxy groups, etc., and containing two or more of the same type in the molecule, also means that, for example, it contains a combination such as epoxy The meaning of a case where a total of two or more heterogeneous groups are contained in the molecule. The term "having two or more in the molecule" means that it is preferably one that contains two or more of the same group in the molecule.

Since the polymer of the component (A) contained in the liquid crystal alignment agent of the present invention has high sensitivity to light, even if it is irradiated with polarized ultraviolet light with a low exposure amount, it can exhibit alignment control performance.

In addition, the polymer of the component (A) contains the thermally crosslinkable group A, and at the same time, by including the thermally crosslinkable group B in the component, even if the sintering time of the liquid crystal alignment agent is short, it can be contained (A ) Crosslinking reaction of the polymer of the component. Thereby, when anisotropy is expressed by the photoreaction in the photo-alignment part, since the anisotropy (memory) is likely to remain in the liquid crystal alignment film, the liquid crystal alignment can be improved and the pretilt angle of the liquid crystal can be expressed.

And, because the part having the photoalignment group represented by the above formula (pa-1) (for example, the group represented by the formula (a-1) described later), the thermally crosslinkable group A and the thermally crosslinkable group B all become polymerized As the side chain in the material, it can also be called "side chain" if necessary. The components of the present invention will be described in detail below.

<Component (A): Specific polymer> [Photoalignment group represented by formula (pa-1)] In the present invention, a part having the photoalignment represented by formula (pa-1) in the molecule is represented as follows, for example The formula (a-1). Moreover, although the structure derived from the monomer represented by the following formula (a-1-m) is mentioned for this part, it is not limited to this. In the formula, I _a is _a monovalent organic group represented by the following formula (pa-1).

In the formula (pa-1), A is represented by a group selected from fluorine, chlorine, and cyano, or an alkoxy group with 1 to 5 carbon atoms, linear or branched alkyl residues as required (This is substituted with 1 cyano group or more than 1 halogen atom as required) substituted pyrimidine-2,5-diyl, pyridine-2,5-diyl, 2,5-thiophene, 2 ,5-furan, 1,4- or 2,6-naphthylene or benzene, R ₁ represents a single bond, oxygen atom, -COO- or -OCO-, R ₂ represents a divalent aromatic group, divalent Alicyclic group, divalent heterocyclic group or divalent condensed cyclic group, R ₃ represents a single bond, oxygen atom, -COO- or -OCO-, R ₄ represents a straight or branched chain with 1 to 40 carbon atoms The alkyl group or a monovalent organic group containing an alicyclic group with 3 to 40 carbons, D represents an oxygen atom, a sulfur atom or -NR _d- (where R _d represents a hydrogen atom or an alkyl group with 1 to 3 carbons ), a represents an integer of 0 to 3, with S _a * represents the bonding position.

In the above formula (a-1) or (a-1-m), S _a represents a spacer unit, and the left bond group of S _a represents an arbitrary spacer on the main chain of the first and second specific polymers. And the bond.

S _a can represent the structure of the following formula (Sp), for example.

In formula (Sp), the left bond of W ₁ represents the bond to M _b , the right bond of W ₃ represents the bond to I _a , and W ₁ , W ₂ and W ₃ each independently represent, single bond, divalent Heterocycle, -(CH ₂ ) _n- (where n represents 1-20), -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -CH=CH-, -CF=CF -, -CF ₂ O-, -OCF ₂ -, -CF ₂ CF ₂ -or -C≡C-, but for these substituents, one or more non-adjacent CH ₂ groups can be independently -O-,- CO-, -CO-O-, -O-CO-, -Si(CH ₃ ) ₂ -O-Si(CH ₃ ) ₂ -, -NR-, -NR-CO-, -CO-NR-,- NR-CO-O-, -OCO-NR-, -NR-CO-NR-, -CH=CH-, -C≡C- or -O-CO-O- (where R independently represents hydrogen or carbon A 1 to 5 linear or branched alkyl group) is substituted, A ₁ and A _{2 are} each independently selected from a single bond, a divalent alkyl group, a divalent aromatic group, a divalent alicyclic group, or In the group of a divalent heterocyclic group, each group may be unsubstituted or one or more hydrogen atoms may be substituted by a fluorine atom, a chlorine atom, a cyano group, a methyl group or a methoxy group.

In the formula (a-1-m), M a represents a polymerizable group. Examples of the polymerizable group include (meth)acrylate, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, Radical polymerizable groups of norbornene, (meth)acrylamide and its derivatives, and silicones. Preferred are (meth)acrylate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, and acrylamide. r is an integer satisfying 1≦r≦3.

In the formula (a-1-m), M _b is selected from a single bond, a (r+1)-valent heterocyclic ring, a linear or branched alkyl group having 1 to 10 carbon atoms, and a (r+1)-valent The group selected for the aromatic group, (r+1) valent alicyclic group, each group may be unsubstituted, or more than one hydrogen atom may also be a fluorine atom, a chlorine atom, a cyano group, a methyl group or a methoxy group The group is substituted.

Examples of the aromatic group in A ₁ , A _{2 ,} and M _b include aromatic hydrocarbons having 6 to 18 carbon atoms such as benzene, biphenyl, and naphthalene. Examples of the alicyclic group in A ₁ , A _{2 ,} and M _b include cyclohexane and alicyclic hydrocarbons having 6 to 12 carbon atoms such as bicyclohexane. Examples of the heterocyclic ring in A ₁ , A _{2 ,} and M _b include nitrogen-containing heterocyclic rings such as pyridine, piperidine, and piperazine. Examples of the alkyl group in A ₁ and A ₂ include linear or branched alkyl groups having 1 to 10 carbon atoms.

From the standpoint of exhibiting good vertical alignment control performance and stable pretilt angle, as the structure of (a-1), the group shown in (pa-1) above or the following (pa-1-a) Shiji. Moreover, the structure derived from the monomer represented by the following formula (pa-1-ma) can be mentioned for this part, but it is not limited to these.

In the formula (pa-1-a) or (pa-1-ma), M a, M b and S _a is the same as defined above. Z is an oxygen atom or a sulfur atom. X _a and X _{b are} each independently a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, or an alkyl group having 1 to 3 carbon atoms. R ₁ is a single bond, an oxygen atom, -COO- or -OCO-. R ₂ is a divalent aromatic group, a divalent alicyclic group, or a divalent heterocyclic group. R ₃ is a single bond, an oxygen atom, -COO- or -OCO-. R ₄ is a linear or branched alkyl group having 1 to 40 carbon atoms or a monovalent organic group having 3 to 40 carbon atoms containing an alicyclic group. R ₅ is an alkyl group having 1 to 3 carbons, an alkoxy group having 1 to 3 carbons, a fluorine atom or a cyano group, and preferably a methyl group, a methoxy group or a fluorine atom. a is an integer of 0-3, and b is an integer of 0-4.

In the formula (pa-1-a) or (pa-1-ma), the linear or branched alkylene group with 1 to 10 carbons as Sa is _a linear or branched chain with 1 to 8 carbons The alkylene group is preferably, for example, methylene, ethylene, n-propylene, n-butylene, t-butylene, n-pentylene, n-hexylene, n-butylene Heptyl and n-octyl are preferred.

Examples of the divalent aromatic group of S _a include 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, 2,3, 5,6-Tetrafluoro-1,4-phenylene, etc.

As S _a divalent alicyclic group, and examples thereof include trans-1,4-cyclohexyl stretch, trans - trans-1,4-linked ring extending cyclohexyl and the like.

As S _a divalent heterocyclic group, and examples thereof include 1,4-pyridyl, 2,5-pyridyl stretch, 1,4-furanyl, 1,4-piperazinyl, 1,4 -Piperidinyl etc.

S _a number of carbon atoms in the alkylene group is preferably those having 1 to 8, carbon atoms preferably an alkylene group having 1 to 6 carbon atoms, more preferably an alkylene group having 1 to 4.

Examples of the divalent aromatic group of R ₂ include 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, 2,3, 5,6-Tetrafluoro-1,4-phenylene, naphthylene, etc.

As the divalent alicyclic group of R ₂ , for example, trans-1,4-cyclohexyl, trans-trans-1,4-bicyclohexyl, and the like can be given.

Examples of the divalent heterocyclic group of R ₂ include 1,4-pyridinyl, 2,5-pyridinyl, 1,4-furanyl, 1,4-piperazinyl, 1,4 -Piperidinyl etc.

R _{2 is} preferably 1,4-phenylene, trans-1,4-cyclohexene, and trans-trans-1,4-bicyclohexene.

Examples of the straight-chain or branched alkyl group having 1 to 40 carbon atoms for R ₄ include a straight or branched chain alkyl group having 1 to 20 carbon atoms. Part or all of the hydrogen atoms of the alkyl group may be fluorine. Replaced by atoms. Examples of the alkyl group include methyl, ethyl, n-propyl, n-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl. , N-nonyl, n-decyl, n-lauryl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, 4,4,4-trifluorobutyl, 4,4,5,5,5-penta Fluoropentyl, 4,4,5,5,6,6,6-heptafluorohexyl, 3,3,4,4,5,5,5-heptafluoropentyl, 2,2,2-trifluoroethyl Base, 2,2,3,3,3-pentafluoropropyl, 2-(perfluorobutyl)ethyl, 2-(perfluorooctyl)ethyl, 2-(perfluorodecyl)ethyl, etc. .

Examples of the monovalent organic group of 3-40 carbons containing an alicyclic group for R ₄ include cholesteryl, cholesteryl, adamantyl, and the following formula (Alc-1) or (Alc-2 ) (In the formula, R _{7 is} each a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 20 carbons, and the alkyl group having 1 to 20 carbons may be substituted with a fluorine atom, and * represents a bonding position).

Examples of the monomer represented by the above formula (pa-1-ma) include structures represented by formulas (paa-1-ma1) to (paa-1-ma18), but are not limited to these. Moreover, in the formula, "E" represents the E body, and "t" represents the cyclohexyl group in the trans form.

[Heat crosslinkable group A and heat crosslinkable group B] The thermally crosslinkable group A and the thermally crosslinkable group B are each independently selected from a carboxyl group, an amino group, an alkoxymethyl amide group, a hydroxymethyl amide group, a hydroxyl group, an epoxy moiety-containing group, and oxa Cyclobutanyl group, thiopropyl ring group, isocyanate group and blocked isocyanate group are groups of organic groups, the thermally crosslinkable group A and thermally crosslinkable group B can be crosslinked by heat, However, the thermally crosslinkable group A and the thermally crosslinkable group B may be the same as each other.

As a combination of such a thermally crosslinkable group A and a thermally crosslinkable group B, one is a carboxyl group, the other is a combination of an epoxy group, an oxetanyl group or a thipropanyl group, one is a hydroxyl group and the other is a combination It is a combination of blocked isocyanate groups, one is a phenolic hydroxyl group, the other is a combination of epoxy, oxetanyl or thipropanyl groups, one is a carboxyl group, and the other is a combination of blocked isocyanate groups, One is an amino group, the other is a combination of blocked isocyanate groups, and both are a combination of N-alkoxymethyl amide, etc. The preferred combination is carboxyl group and epoxy group, hydroxyl group and blocked isocyanate group and the like.

To introduce this thermally crosslinkable group A into the polymer of the component (A), the monomer having the thermally crosslinkable group A may be copolymerized.

In addition, when the liquid crystal alignment agent used in the present invention satisfies the requirement Z1, when the polymer of component (A) is produced, a monomer having a thermally crosslinkable group A and a monomer having a thermally crosslinkable group B The two parties can be copolymerized.

As the monomer having a thermally crosslinkable group, for example, acrylic acid, methacrylic acid, crotonic acid, mono-(2-(acryloxy) ethyl) phthalate, mono-(2- (Methacryloxy)ethyl)phthalate, N-(carboxyphenyl)maleimide, N-(carboxyphenyl)methacrylamide, and N-(carboxyphenyl) ) Monomers with carboxyl groups such as acrylamide;

2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate Ester, 2,3-dihydroxypropyl acrylate, 2,3-dihydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, caprolactone 2-( Acrylic oxy) ethyl ester, caprolactone 2-(methacrylic oxy) ethyl ester, poly(ethylene glycol) ethyl ether acrylate, poly(ethylene glycol) ethyl ether methacrylate , 5-propenyloxy-6-hydroxynorbornene-2-carboxy-6-lactone, and 5-methacryloxy-6-hydroxynorbornene-2-carboxy-6-lactone, etc. Hydroxyl monomers;

Hydroxystyrene, N-(hydroxyphenyl)methacrylamide, N-(hydroxyphenyl)acrylamide, N-(hydroxyphenyl)maleimide, and N-(hydroxyphenyl)maleimide Monomers with phenolic hydroxyl groups such as Leximine;

Monomers with amino groups such as amino ethyl acrylate, amino ethyl methacrylate, amino propyl acrylate, and amino propyl methacrylate;

N-hydroxymethyl(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-ethoxymethyl(meth)acrylamide, N-butoxymethyl (Meth)acrylamide and other (meth)acrylamide compounds substituted by hydroxymethyl or alkoxymethyl;

Allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, 2-methyl glycidyl methacrylate, α-ethyl glycidyl acrylate, α-n-propyl glycidyl acrylate , Α-n-Butyl glycidyl acrylate, 3,4-epoxybutyl acrylate, 3,4-epoxybutyl methacrylate, 6,7-epoxyheptyl acrylate, 6,7 methacrylate -Epoxyheptyl ester, α-ethyl acrylate-6,7-epoxyheptyl ester, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzene Methyl glycidyl ether, 3,4-epoxycyclohexyl methyl methacrylate, 3-vinyl-7-oxacyclo[4.1.0]heptane, 1,2-epoxy-5-hexyl Alkenes, 1,7-octadiene monoepoxides and other monomers with groups containing epoxy sites;

3-(acryloxymethyl)oxetane, 3-(acryloxymethyl)-2-methyloxetane, 3-(acryloxymethyl)-3- Ethyloxetane, 3-(acryloxymethyl)-2-trifluoromethyloxetane, 3-(acryloxymethyl)-2-pentafluoroethyloxa Cyclobutane, 3-(propenyloxymethyl)-2-phenyloxetane, 3-(propenyloxymethyl)-2,2-difluorooxetane, 3- (Acryloyloxymethyl)-2,2,4-trifluorooxetane, 3-(acryloyloxymethyl)-2,2,4,4-tetrafluorooxetane, 3-(2-propenyloxyethyl)oxetane, 3-(2-propenyloxyethyl)-2-ethyloxetane, 3-(2-propenyloxyethyl) Ethyl)-3-ethyloxetane, 3-(2-propenyloxyethyl)-2-trifluoromethyloxetane, 3-(2-propenyloxyethyl) )-2-Pentafluoroethyloxetane, 3-(2-propenyloxyethyl)-2-phenyloxetane, 3-(2-propenyloxyethyl)- 2,2-Difluorooxetane, 3-(2-propenyloxyethyl)-2,2,4-trifluorooxetane, 3-(2-propenyloxyethyl) )-2,2,4,4-tetrafluorooxetane and other acrylates; 3-(methacryloxymethyl)oxetane, 3-(methacryloxymethyl)- 2-Methyloxetane, 3-(methacryloxymethyl)-3-ethyloxetane, 3-(methacryloxymethyl)-2-trifluoromethyl Oxetane, 3-(methacryloxymethyl)-2-pentafluoroethyloxetane, 3-(methacryloxymethyl)-2-phenyloxetane Alkyl, 3-(methacryloxymethyl)-2,2-difluorooxetane, 3-(methacryloxymethyl)-2,2,4-trifluorooxetane Alkane, 3-(methacryloxymethyl)-2,2,4,4-tetrafluorooxetane, 3-(2-methacryloxyethyl)oxetane, 3 -(2-Methylpropenoxyethyl)-2-ethyloxetane, 3-(2-Methylpropenoxyethyl)-3-ethyloxetane, 3-( 2-Methylpropenoxyethyl)-2-Trifluoromethyloxetane, 3-(2-Methylpropenyloxyethyl)-2-pentafluoroethyloxetane, 3 -(2-Methylpropenoxyethyl)-2-Phenyloxetane, 3-(2-Methylpropenoxyethyl)-2,2-Difluorooxetane, 3 -(2-Methylpropenoxyethyl)-2,2,4-trifluorooxetane, 3-(2-Methylpropenoxyethyl)-2,2,4,4-tetra Monomers with oxetanyl groups such as fluorooxetane;

2,3-Epithiopropyl acrylate or methacrylate, and 2- or 3- or 4-(β-epithiopropylthiomethyl)styrene, 2- or 3- or 4-(β -Epithiopropoxymethyl)styrene, 2- or 3- or 4-(β-epithiopropylthio)styrene, 2- or 3- or 4-(β-epithiopropyloxy) Styrene and other monomers with a thipropane ring group;

Acrylic acid 2-(0-(1'-methylpropyleneamino)carboxyamino)ethyl, acrylic acid 2-(3,5-dimethylpyrazolyl)carbonylamino)ethyl, methacrylic acid 2-(0-(1'-Methylpropyleneamino)carboxyamino)ethyl, 2-(3,5-dimethylpyrazolyl)carbonylamino)ethyl methacrylate, etc. have blocked Type isocyanate group monomers, etc. In addition, the term “(meth)acrylamide” means both acrylamide and methacrylamide.

In addition, for the present invention, when a specific copolymer is to be obtained, the monomer having a photo-alignment group represented by the above formula (a-1-m), and a thermally crosslinkable group A and optionally thermally crosslinkable In addition to the monomers of group B, other monomers copolymerizable with these monomers may be used in combination.

As specific examples of such other monomers, acrylate compounds, methacrylate compounds, maleimide compounds, acrylonitrile, maleic anhydride, styrene compounds, vinyl compounds, N-methoxymethyl Acrylamide compounds such as methacrylamide, N-butoxymethyl(meth)acrylamide, acrylamide, and monomers having a nitrogen-containing aromatic heterocyclic group and a polymerizable group.

Examples of acrylate compounds include methacrylate, ethacrylate, isopropyl acrylate, benzyl methacrylate, naphthalene acrylate, anthracenyl acrylate, anthryl methacrylate, and phenyl acrylate. Ester, 2,2,2-trifluoroethyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, isobornyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol Acrylate, 2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, 3-methoxybutyl acrylate, 2-methyl-2-adamantyl acrylate, 2-propyl-2- Adamantyl acrylate, 8-methyl-8-tricyclodecyl acrylate, 8-ethyl-8-tricyclodecyl acrylate, etc.

Examples of the methacrylate compound include methacrylate, ethyl methacrylate, isopropyl methacrylate, cetyl methacrylate, and octadecyl methacrylate. , Benzyl methacrylate, naphthalene methacrylate, anthracenyl methacrylate, anthracenyl methyl methacrylate, phenyl methacrylate, 2,2,2-trifluoroethyl methyl Acrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2 -Ethoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 3-methoxybutyl methacrylate, 2-methyl-2-adamantyl methacrylate, 2-propyl- 2-adamantyl methacrylate, 8-methyl-8-tricyclodecyl methacrylate, 8-ethyl-8-tricyclodecyl methacrylate, etc.

As the aforementioned (meth)acrylamide compound, for example, acrylamide, methacrylamide, N-methacrylamide, N,N-dimethylacrylamide, N,N-diethyl Base allyl amide and so on.

Examples of the aforementioned vinyl compounds include methyl vinyl ether, benzyl vinyl ether, vinyl naphthalene, vinyl carbazole, allyl glycidyl ether, and 3-vinyl-7-oxa Ring [4.1.0] heptane and so on.

As said styrene compound, styrene, methylstyrene, chlorostyrene, bromostyrene, etc. are mentioned, for example.

As said maleimide compound, maleimide, N-methylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide, etc. are mentioned, for example.

The nitrogen-containing aromatic heterocycle contains at least one structure selected from the group consisting of the following formulas [Na] to [Nb] (where Z ₂ is a linear or branched alkyl group having 1 to 5 carbons), Preferably, it contains 1 to 4 aromatic cyclic hydrocarbons.

Specific examples include oxazole ring, thiazole ring, pyridine ring, pyrimidine ring, quinoline ring, 1-pyrazoline ring, isoquinoline ring, thiadiazole ring, pyridazine ring, triazine ring, pyrazine ring, Phenanthroline ring, quinoxaline ring, benzothiazole ring, oxadiazole ring, acridine ring, etc. Furthermore, the carbon atoms of these nitrogen-containing aromatic heterocycles may have heteroatom-containing substituents. Among these, for example, a pyridine ring can be mentioned.

Examples of monomers having a nitrogen-containing aromatic heterocyclic group and a polymerizable group include 2-(2-pyridylcarbonyloxy)ethyl (meth)acrylate and 2-(3-pyridylcarbonyl) Oxy)ethyl (meth)acrylate, 2-(4-pyridylcarbonyloxy)ethyl (meth)acrylate and the like.

The other monomers used in the present invention may be used alone or in combination of two or more kinds of monomers.

The photoreactive part represented by the above formula (pa-1) contained in the polymer of the present invention may be used alone or in combination of two or more parts. The photoreactive site represented by the above formula (pa-1) is preferably contained in a proportion of 5-50 mol%, 10-40 mol%, or 15-35 mol% of the total repeating unit of the polymer of component (A).

The part having the thermally crosslinkable group contained in the polymer of the present invention can be used alone or in combination with two or more parts containing the thermally crosslinkable group A and the thermally crosslinkable group B. . The amount of introduction of the portion having the thermally crosslinkable group is preferably 50 to 95 mol%, 60 to 90 mol%, or 65 to 85% of the total repeating unit of the polymer of the component (A).

The content of the structure derived from the above-mentioned other monomers is preferably 0-40 mol%, 0-30 mol%, or 0-20 mol% of the total repeating unit of the polymer containing the component (A).

＜Method of manufacturing specific polymer＞ The specific polymer of the component (A) contained in the liquid crystal alignment agent of the present invention can be copolymerized with a monomer having a photo-alignment group represented by the above formula (pa-1), and the above-mentioned thermally crosslinkable group A The monomer and the monomer having the above-mentioned thermally crosslinkable group B as required. In addition, it may be copolymerized with the other monomers mentioned above.

The method for producing the specific polymer of the component (A) in the present invention is not particularly limited, but general methods used in industry can be used. Specifically, it can be produced by cationic polymerization, radical polymerization, or anion polymerization using monomer vinyl. Among these, radical polymerization is particularly preferred from the viewpoint of ease of reaction control. As a polymerization initiator for radical polymerization, known compounds such as a radical polymerization initiator or a reversible addition-cracking type chain transfer (RAFT) polymerization reagent can be used.

The radical thermal polymerization initiator is a compound that generates radicals by heating above the decomposition temperature. As such radical thermal polymerization initiators, for example, ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), diacyl peroxides (acetyl peroxide Compounds, benzyl peroxide, etc.), hydroperoxides (hydrogen peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxides (two -tert-butyl peroxide, dicumyl peroxide, dilauryl peroxide, etc.), peroxyketals (dibutylperoxycyclohexane, etc.), alkyl peresters (per Oxy-neodecanoic acid-tert-butyl ester, peroxypivalic acid-tert-butyl ester, peroxy-2-ethylcyclohexane acid-tert-pentyl ester, etc.), persulfates (persulfuric acid) Potassium, sodium persulfate, ammonium persulfate, etc.), azo compounds (azobisisobutyronitrile and 2,2'-bis(2-hydroxyethyl)azobisisobutyronitrile, etc.). Such a radical thermal polymerization initiator may be used individually by 1 type, or may be used in combination of 2 or more types.

The radical photopolymerization initiator is not particularly limited as long as it is a compound that can start radical polymerization by light irradiation. Such radical photopolymerization initiators include benzophenone, Michler’s ketone, 4,4'-bis(diethylamino)benzophenone, xanthone, thioxanthone, isopropyl Known compounds such as xanthone. These compounds may be used alone or in combination of two or more kinds. The radical polymerization method is not particularly limited, and an emulsion polymerization method, a suspension polymerization method, a dispersion polymerization method, a precipitation polymerization method, a bulk polymerization method, a solution polymerization method, etc. can be used.

The solvent used for the polymerization reaction of the specific polymer of the component (A) is not particularly limited as long as it can dissolve the produced polymer. As specific examples, the solvents described in the section of the below-mentioned "solvent" can be given, for example, N-alkyl-2-pyrrolidones, dialkylimidazolinones, lactones, and carbonates can be given. , Ketones, compounds represented by formula (Sv-1) and compounds represented by formula (Sv-2), tetrahydrofuran, 1,4-dioxane, dimethyl sulfoxide, dimethyl sulfoxide, etc. These solvents can be used alone or in mixture. Moreover, even if the solvent cannot dissolve the produced polymer, if it is within the range of the polymer that does not precipitate, it can be mixed with the above-mentioned solvent and used. In addition, for radical polymerization, since oxygen in the solvent will hinder the polymerization reaction, it is better to use an organic solvent that has been degassed as much as possible.

The polymerization temperature during radical polymerization can be selected from any temperature of 30 to 150°C, but it is preferably in the range of 50 to 100°C. In addition, the reaction can be carried out at any concentration, but the monomer concentration is preferably 1-50% by mass, more preferably 5-30% by mass. The reaction is carried out at a high concentration in the initial stage, and an organic solvent can be added afterwards. For the above-mentioned free radical polymerization reaction, if the ratio of the radical polymerization initiator to the monomer is large, the molecular weight of the obtained polymer will become smaller, because if it is too small, the molecular weight of the polymer obtained will become larger, so the The ratio of the starting agent is preferably 0.1-10 mol% of the monomer to be polymerized. In addition, various monomer components, solvents, initiators, etc. may be added during polymerization.

[Recycling of polymers] When recovering the produced polymer from the reaction solution obtained by the above-mentioned reaction, the reaction solution is poured into a weak solvent to precipitate these polymers. Examples of weak solvents used for precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, heptane, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, water, and the like. The polymer deposited in a weak solvent can be recovered by filtration, and can be dried under normal pressure or reduced pressure with constant temperature or heating. In addition, after the polymer recovered by precipitation is re-dissolved in an organic solvent, and the operation of re-precipitation and recovery is repeated 2 to 10 times, impurities in the polymer can be reduced. As the weak solvent in this case, for example, alcohols, ketones, hydrocarbons, etc. can be mentioned. When three or more kinds of weak solvents selected from these are used, the purification efficiency can be further improved, so it is preferable.

(A) The molecular weight of the specific polymer of the component, considering the strength of the resulting coating film, the workability during coating film formation, and the uniformity of the coating film, is the weight average measured by the GPC (Gel Permeation Chromatography) method The molecular weight is preferably 2,000 to 1,000,000, preferably 5,000 to 100,000.

＜(B) Ingredient＞ When the liquid crystal alignment agent used in the present invention satisfies the requirement Z2, it contains a crosslinking agent as the (B) component. As (B) component, the crosslinking agent which has 2 or more heat-crosslinkable groups B is mentioned.

Examples of the crosslinking agent of component (B) include epoxy compounds, compounds having two or more amine groups, methylol compounds, isocyanate compounds, phenol resin compounds, blocked isocyanate compounds and other low-molecular compounds, N-alkane Polymers of oxymethacrylamide, polymers of compounds having epoxy groups, polymers of compounds having isocyanate groups, etc.

Specific examples of the above epoxy compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether. Glyceryl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol 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, and N,N,N',N'-tetraglycidyl-4, 4'-diaminodiphenylmethane, etc.

Examples of compounds having two or more amine groups include diamines such as alicyclic diamines, aromatic diamines, aromatic-aliphatic diamines, and aliphatic diamines.

Examples of alicyclic diamines include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 4, 4'-Diamino-3,3'-dimethyldicyclohexylamine, isophoronediamine, etc.

Examples of aromatic diamines include o-phenylene diamine, m-phenylene diamine, p-phenylene diamine, 2,4-diaminotoluene, and 2,5-diaminotoluene , 3,5-diaminotoluene, 1,4-diamino-2-methoxybenzene, 2,5-diamino-p-xylene and 1,3-diamino-4-chlorobenzene Wait.

Examples of aromatic-aliphatic diamines include 3-aminobenzylamine, 4-aminobenzylamine, 3-amino-N-methylbenzylamine, and 4-aminobenzylamine. -N-methylbenzylamine, 3-aminophenethylamine, 4-aminophenethylamine, 3-amino-N-methylphenethylamine, 4-amino-N-methyl Phenylethylamine, 3-(3-aminopropyl)aniline, 4-(3-aminopropyl)aniline, 3-(3-methylaminopropyl)aniline, 4-(3-methyl Aminopropyl)aniline, 3-(4-aminobutyl)aniline, 4-(4-aminobutyl)aniline, 3-(4-methylaminobutyl)aniline, 4-(4 -Methylaminobutyl)aniline, 3-(5-aminopentyl)aniline, 4-(5-aminopentyl)aniline, 3-(5-methylaminopentyl)aniline, 4- (5-Methylaminopentyl)aniline, 2-(6-aminonaphthalene)methylamine, 3-(6-aminonaphthalene)methylamine, 2-(6-aminonaphthalene)ethylamine , 3-(6-Aminonaphthalene)ethylamine, etc.

Examples of aliphatic diamines include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, and 1,5-diaminopentane , 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane , 1,3-diamino-2,2-dimethylpropane, 1,6-diamino-2,5-dimethylhexane, 1,7-diamino-2,5-dimethylpropane Heptane, 1,7-diamino-4,4-dimethylheptane, 1,7-diamino-3-methylheptane, 1,9-diamino-5-methylheptane Ethane etc.

Specific examples of methylol compounds include compounds such as alkoxymethylated glycol urea, alkoxymethylated benzoguanamine, and alkoxymethylated melamine.

As a specific example of the alkoxymethylated glycol urea, for example, 1,3,4,6-four (methoxymethyl) glycol urea, 1,3,4,6-four ( Butoxymethyl) glycol urea, 1,3,4,6-tetra-(hydroxymethyl) glycol urea, 1,3-bis(hydroxymethyl)urea, 1,1,3,3- Four (butoxymethyl) urea, 1,1,3,3-four (methoxymethyl) urea, 1,3-bis(hydroxymethyl)-4,5-dihydroxy-2-imidazoline Ketones, and 1,3-bis(methoxymethyl)-4,5-dimethoxy-2-imidazolinone, etc. Examples of commercially available products include compounds such as ethylene glycol urea compounds manufactured by Mitsui Cytec Co., Ltd. (trade names: Cymel (registered trademark) 1170, Powder link (registered trademark) 1174), and methylated urea resins (trade name: UFR (registered trademark) 65), butylated urea resin (trade name: UFR (registered trademark) 300, U-VAN10S60, U-VAN10R, U-VAN11HV), DIC (shares) urea/formaldehyde resin (high condensation Model, trade name: Becamine (registered trademark) J-300S, same as P-955, same as N), etc.

As a specific example of an alkoxymethylated benzoguanamine, tetramethoxymethyl benzoguanamine etc. are mentioned, for example. Examples of sales items include Mitsui Cytec (trade name: Cymel (registered trademark) 1123), Sanwa Chemical (trade name: Nicaraq (registered trademark) BX-4000, the same as BX-37). , Same as BL-60, same as BX-55H) etc.

As a specific example of alkoxymethylated melamine, hexamethoxymethyl melamine etc. are mentioned, for example. As sales products, methoxymethyl melamine compounds manufactured by Mitsui Cytec Co., Ltd. (trade names: Cymel (registered trademark) 300, the same 301, the same 303, the same 350), butoxymethyl melamine Compound (trade name: My coat (registered trademark) 506, same as 508), Sanwa Chemical's methoxymethyl melamine compound (trade name: Nicaraq (registered trademark) MW-30, same as MW-22, same as MW- 11. Same as MS-001, same MX-002, same MX-730, same MX-750, same MX-035), butoxymethyl melamine compound (trade name: Nicaraq (registered trademark) MX-45, same MX-410, same as MX-302) etc.

Moreover, it may be a compound obtained by condensing a melamine compound, a urea compound, a glycol urea compound, and a benzoguanamine compound in which the hydrogen atoms of these amino groups are substituted with methylol or alkoxymethyl. For example, a high molecular weight compound produced from a melamine compound and a benzoguanamine compound described in US Patent No. 6,323,310 can be mentioned. As a commercial product of the melamine compound, there may be a trade name: Cymel (registered trademark) 303 (manufactured by Mitsui Cytec Co., Ltd.), etc. As a commercial product of the benzoguanamine compound, there may be a trade name: Cymel (Registered trademark) 1123 (Mitsui Cytec (stock) system), etc.

Specific examples of isocyanate compounds include, for example, VESTANAT B1358/100, VESTAGON BF 1540 (above, isocyanurate-type modified polyisocyanate, manufactured by Degussa Japan (Stock)), Takenate (registered trademark) B-882N, the same B-7075 (above, isocyanurate type modified polyisocyanate, manufactured by Mitsui Chemicals Co., Ltd.), etc.

As specific examples of the phenol resin compound, the following compounds can be cited, but the phenol resin compound is not limited to the following compound examples.

As specific examples of the compound having two or more hydroxyalkylamido groups at the molecular terminal, for example, the following compounds or Primid XL-552, Primid SF-4510 can be given.

Examples of blocked isocyanate compounds include Coronate AP Stable M, Coronate 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (above, manufactured by Japan Polyurethane Industry Co., Ltd.), Takenate B-830, B -815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N (above, manufactured by Mitsui Chemicals Co., Ltd.), etc.

Furthermore, as the polymer of the above-mentioned N-alkoxymethacrylamide, for example, the use of N-hydroxymethyl(meth)acrylamide, N-methoxymethyl(meth)acrylamide , N-ethoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide and other hydroxymethyl or alkoxymethyl substituted acrylamide compounds or methyl A polymer produced from an acrylamide compound.

As specific examples of such polymers, for example, poly(N-butoxymethacrylamide), copolymers of N-butoxymethacrylamide and styrene, N-hydroxymethylmethyl The copolymer of acrylamide and methacrylate, the copolymer of N-ethoxymethylmethacrylamide and benzyl methacrylate, and the copolymer of N-butoxymethacrylamide and Copolymers of benzyl methacrylate and 2-hydroxypropyl methacrylate, etc. The weight average molecular weight of such a polymer is 1,000 to 200,000, preferably 3,000 to 150,000, more preferably 3,000 to 50,000.

As the polymer of the compound having an epoxy group, for example, the use of glycidyl methacrylate, 3,4-epoxycyclohexylmethylmethacrylate, 3,4-epoxycyclohexylmethylmethacrylate can be mentioned. A polymer produced from a compound having an epoxy group such as acrylate.

As specific examples of such polymers, for example, poly(3,4-epoxycyclohexyl methacrylate), poly(glycidyl methacrylate), glycidyl methacrylate and methyl methacrylate can be cited. Copolymers of methyl methacrylate, copolymers of 3,4-epoxycyclohexyl methacrylate and methacrylate, copolymers of glycidyl methacrylate and styrene, etc. The weight average molecular weight of such a polymer is 1,000 to 200,000, preferably 3,000 to 150,000, more preferably 3,000 to 50,000.

As a polymer of the compound having the above-mentioned isocyanate group, for example, the use of 2-isocyanatoethyl methacrylate (KarenzMOI [registered trademark], manufactured by Showa Denko Corporation), 2-isocyanatoethyl acrylate Esters (KarenzAOI [registered trademark], Showa Denko Corporation) and other compounds having isocyanate groups, or 2-(0-[1'-methylpropylene amino] carboxyl amino) ethyl methacrylate (KarenzMOI-BM[registered trademark], Showa Denko Corporation), 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate (KarenzMOI-BP[registered trademark] , Showa Denko Co., Ltd.) and other polymers made of compounds with blocked isocyanate groups.

As specific examples of such polymers, for example, poly(2-isocyanatoethyl acrylate), poly(2-(0-[1'-methylpropyleneamino]carboxyamino)ethyl Methacrylate), 2-isocyanatoethyl methacrylate and styrene copolymer, 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethylmethacrylate and Copolymers of methmethacrylate, etc. The weight average molecular weight of such a polymer is 1,000 to 200,000, preferably 3,000 to 150,000, more preferably 3,000 to 50,000.

These crosslinking agents can be used individually or in combination of 2 or more types.

When the liquid crystal alignment agent used in the present invention contains the crosslinking agent of component (B), the content is based on 100 parts by mass of the resin of component (A), preferably 1 part by mass to 100 parts by mass. It is preferably 1 part by mass to 80 parts by mass.

[Modulation of liquid crystal alignment agent] The liquid crystal alignment agent used in the present invention is preferably prepared as a coating liquid suitable for the formation of the liquid crystal alignment film. That is, the liquid crystal alignment agent of the present invention is preferably prepared by dissolving the resin component to be formed into a resin film in an organic solvent. Here, the resin component is the specific polymer of the component (A) already explained. At this time, the content of the specific polymer is preferably 0.5-20% by mass relative to the entire liquid crystal alignment agent, preferably 1-20% by mass, more preferably 1-15% by mass, particularly preferably 1-10% by mass %.

＜Solvent＞ The solvent contained in the liquid crystal alignment agent used in the present invention is not particularly limited as long as it can dissolve the (A) component and optionally the (B) component. The solvent contained in the liquid crystal alignment agent may be one type, or a mixture of two or more types may be used. Moreover, even if it is not a solvent which dissolves (A) component or (B) component, the solvent which dissolves (A) component or (B) component can be used together. At this time, if the surface energy of the solvent that does not dissolve the (A) component or the (B) component is lower than the solvent that dissolves the (A) component or (B) component, the coating property of the liquid crystal alignment agent on the substrate can be improved. Good, so better.

As specific examples, N-alkyl-2-pyrrolidone such as water, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N,N-dimethyl Methyl methamide, N,N-dimethylacetamide, N-methylcaprolactam, tetramethylurea, 3-methoxy-N,N-dimethylpropaneamide, 3-ethyl Dialkylimidazoles such as oxy-N,N-dimethylpropaneamide, 3-butoxy-N,N-dimethylpropaneamide, 1,3-dimethyl-2-imidazolinone, etc. Lactones, γ-butyrolactone, γ-valerolactone, δ-valerolactone, etc., carbonates such as ethylene carbonate, propylene carbonate, methanol, ethanol, propanol, iso Propanol, 3-methyl-3-methoxybutanol, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, isoamyl methyl ketone, methyl isopropyl ketone, diisopropyl ketone Butyl ketone, cyclohexanone, cyclopentanone, methyl isobutyl ketone, 4-hydroxy-4-methyl-2-pentanone and other ketones, the compound represented by the following formula (Sv-1) and the following The compound represented by the formula (Sv-2), 4-methyl-2-pentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, 2-methylcyclohexyl acetate Ester, butyl butyrate, isoamyl butyrate, diisobutyl methanol, diisoamyl ether, etc.

In formulas (Sv-1) to (Sv-2), Y ₁ and Y _{2 are} each independently a hydrogen atom or a monovalent hydrocarbon group with 1 to 6 carbon atoms, X ₁ is an oxygen atom or -COO-, and X ₂ is a single bond Or a carbonyl group, R ₁ is an alkanediyl group having 2 to 4 carbons. n ₁ is an integer of 1-3. When n ₁ is 2 or 3, a plurality of R ₁ may be the same or different. Z ₁ is a divalent hydrocarbon group having 1 to 6 carbons, and Y ₃ and Y _{4 are} each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbons).

In the formula (Sv-1), examples of the monovalent hydrocarbon groups having 1 to 6 carbons for Y ₁ and Y ₂ include, for example, monovalent chain hydrocarbon groups having 1 to 6 carbons, and monovalent esters having 1 to 6 carbons. Cyclic hydrocarbon groups and monovalent aromatic hydrocarbon groups having 1 to 6 carbon atoms, etc. Examples of the monovalent chain hydrocarbon group having 1 to 6 carbons include an alkyl group having 1 to 6 carbons, and the like. The alkanediyl group of R ₁ may be linear or branched.

In the formula (Sv-2), examples of the divalent hydrocarbon group having 1 to 6 carbons in Z ₁ include alkanediyl having 1 to 6 carbons. Examples of the monovalent hydrocarbon groups having 1 to 6 carbons for Y ₃ and Y ₄ include monovalent chain hydrocarbon groups having 1 to 6 carbons, monovalent alicyclic hydrocarbon groups having 1 to 6 carbons, and 1 to 6 carbons. The monovalent aromatic hydrocarbon group and so on. Examples of the monovalent chain hydrocarbon group having 1 to 6 carbons include an alkyl group having 1 to 6 carbons, and the like.

As specific examples of the solvent represented by the formula (Sv-1), for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i- Propyl ether, ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol monohexyl ether, ethylene glycol dimethyl ether, ethylene glycol monoacetate, ethylene glycol diacetate, ethylene diacetate Alcohol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether Base ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether, dipropylene glycol dimethyl ether Ether, dipropylene glycol monomethyl ether, propylene glycol diacetate, ethylene glycol, 1,4-butanediol, 3-methoxybutyl acetate, 3-ethoxybutyl acetate, etc.;

As specific examples of the solvent shown in (Sv-2), for example, methyl glycolate, ethyl glycolate, butyl glycolate, ethyl lactate, butyl lactate, isoamyl lactate, ethyl-3 -Ethoxypropionate, methyl-3-methoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxy Propyl propionate, butyl 3-methoxypropionate, etc.

As the aforementioned solvent, a boiling point of 80 to 200°C is preferred. It is preferably from 80°C to 180°C. Preferred solvents include N,N-dimethylformamide, tetramethylurea, 3-methoxy-N,N-dimethylpropaneamide, Propanol, isopropanol, 3-methyl-3-methoxybutanol, ethyl amyl ketone, methyl ethyl ketone, isoamyl methyl ketone, methyl isopropyl ketone, diisobutyl Ketones, cyclohexanone, cyclopentanone, methyl isobutyl ketone, 4-hydroxy-4-methyl-2-pentanone, 4-methyl-2-pentyl acetate, 2-ethylbutyl acetate, Cyclohexyl acetate, 2-methylcyclohexyl acetate, butyl butyrate, isoamyl butyrate, diisobutyl methanol, diisopentyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl Base ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol monoacetic acid Ester, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate , Propylene glycol monobutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monomethyl ether, 3-methoxybutyl acetate, methyl glycolate, ethyl glycolate, butyl glycolate, Ethyl lactate, butyl lactate, isoamyl lactate, ethyl-3-ethoxypropionate, methyl-3-methoxypropionate, ethyl 3-methoxypropionate, etc. When the boiling point is in this range, it is particularly preferable to coat a liquid crystal alignment agent containing the aforementioned solvent on a plastic substrate described later.

＜Other ingredients＞ The liquid crystal alignment agent used in the present invention may contain other components other than the above-mentioned (A) component and (B) component. Examples of such other components include crosslinking catalysts, compounds that can improve film thickness uniformity or surface smoothness when applied to a liquid crystal alignment agent, and compounds that want to improve the adhesion between the liquid crystal alignment film and the substrate. However, It is not limited to these.

＜Crosslinking catalyst＞ In the liquid crystal alignment agent used in the present invention, a crosslinking catalyst may be added for the purpose of promoting the reaction between the thermally crosslinkable group A and the thermally crosslinkable group B. Examples of such crosslinking catalysts include p-toluenesulfonic acid, camphor acid, trifluoromethanesulfonic acid, p-phenolsulfonic acid, 2-naphthalenesulfonic acid, tritoluenesulfonic acid, and p-xylene-2-sulfonic acid. Acid, m-xylene-2-sulfonic acid, 4-ethylbenzenesulfonic acid, 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid, perfluoro(2-ethoxyethane) sulfonic acid, five Sulfonic acids such as fluoroethanesulfonic acid, nonafluorobutane-1-sulfonic acid, and dodecylbenzenesulfonic acid, or hydrates or salts thereof. Examples of compounds that generate acid by heat include bis(toluenesulfonyloxy)ethane, bis(toluenesulfonyloxy)propane, bis(toluenesulfonyloxy)butane, and p-nitro Benzyl toluene sulfonate, o-nitrobenzyl toluene sulfonate, 1,2,3-benzyl ginseng (methanesulfonate), p-toluenesulfonate pyridinium salt, p-toluenesulfonate Morpholine salt, p-ethyl tosylate, p-propyl toluenesulfonate, p-butyl toluenesulfonate, p-isobutyl toluenesulfonate, p-methyl toluenesulfonate , P-phenethyl toluenesulfonate, cyanomethyl p-toluenesulfonate, 2,2,2-trifluoroethyl p-toluenesulfonate, 2-hydroxybutyl p-toluenesulfonate , N-ethyl-p-toluenesulfonamide and so on.

[Compounds that want to improve the uniformity of film thickness or surface smoothness] As the compound intended to improve the uniformity or surface smoothness of the film thickness, a fluorine-based surfactant, a silicone-based surfactant, a non-ionic surfactant, and the like can be mentioned. Specifically, for example, EFTOP (registered trademark) 301, EF303, EF352 (manufactured by Tochem Products), Megafac (registered trademark) F171, F173, R-30 (manufactured by DIC Corporation), FLUORADFC430, FC431 (Sumitomo 3M) Manufacture), Asahi Guard (registered trademark) AG710 (manufactured by Asahi Glass Co., Ltd.), Surflon (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by AGCSeimi Chemical Corporation), etc. The use ratio of these surfactants is preferably 0.01 to 2 parts by mass, preferably 0.01 to 1 part by mass, with respect to 100 parts by mass of the resin component contained in the polymer composition.

[Compounds to improve the adhesion between the liquid crystal alignment film and the substrate] As a specific example of the compound intended to improve the adhesion between the liquid crystal alignment film and the substrate, the following functional silane-containing compound and the like can be cited. For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-urea Propyl trimethoxysilane, 3-ureapropyl triethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltri Ethoxysilane, N-triethoxysilylpropylamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane Alkyl, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-dinonyl 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 Silane, N-bis(oxyethylene)-3-aminopropyltriethoxysilane and other compounds containing amino-based silane. When using a compound to improve adhesion to the substrate, the usage amount is preferably 0.1 to 30 parts by mass, preferably 1 part by mass, with respect to 100 parts by mass of the resin component contained in the polymer composition ~20 parts by mass.

In a certain embodiment, a photosensitizer can be used as an additive to increase the photoreactivity of the photoalignment group. Specific examples include aromatic 2-hydroxyketones (benzophenone), coumarin, ketocoumarin, carbonyl biscoumarin, acetophenone, anthraquinone, xanthone, thioxanthone and Acetophenone ketal and so on.

For the liquid crystal alignment agent used in the present invention, the aforementioned resin components may all be the above-mentioned specific polymers, or may be mixed with other polymers (hereinafter also referred to as "other polymers"). At this time, as the content of the other polymer in the resin component, the total 100 parts by mass of the component (A) and the other polymer may be 5 to 95 parts by mass or 10 to 90 parts by mass. As such other polymers, for example, poly(meth)acrylate, polyamide, polyamide, or polyimide, etc., do not meet at least one of the above-mentioned specific polymer constituent requirements.

As the other polymer, polyimide and its precursor (hereinafter also referred to as polyimide component) are preferable, and a polymer having a surface energy close to that of the polymer of the (A) component is preferred. For example, the acrylic component of component (A) is basically low in polarity and low in surface energy. On the other hand, the polarity of the polyimide component is high, and the surface energy is high. However, if the difference between the surface energy of the two components is too large, agglomeration occurs because they cannot be fully compatible, making it a film with unevenness, and there is a problem that the process width becomes narrow due to dripping and unevenness. The concerns. Here, by reducing the polarity of the polyimide component, although the surface energy is higher than that of the acrylic component, the difference can be controlled to a small value. As a method of reducing the polarity of the polyimide component, there is a method of mixing with the component (A) after chemical imidization, or a method of introducing a side chain.

As such a polymer, a polymer obtained by polymerizing a tetracarboxylic acid derivative such as a known tetracarboxylic dianhydride with a known diamine, followed by chemical imidization, and a diamine having a side chain The polyimide precursor, the polyimide obtained by the imidization of the polyimide, the polyimide precursor obtained by using the diamine with the tertiary butoxycarbonyloxy group, the polyimide precursor Polyimine obtained by imidization, etc. Because the side chain or chemical imidization can make the surface energy close to the acrylic polymer of component (A), when the liquid crystal alignment agent is applied and fired to form a cured film, it does not cause aggregation, etc. Can impart a flat hardened film. Examples of diamines having side chains include the diamines represented by formulas (2), (3), (4), and (5) described in paragraphs [0023] to [0039] of International Patent Application Publication WO2016/125870 And as specific examples thereof, diamines represented by formulas [A-1] to [A-32]. Examples of the diamine having a tertiary butoxycarbonyloxy group include the formulas [A-1] and [A-2] described in paragraphs [0011] to [0034] of International Patent Application Publication WO2017/119461, The diamine of the structure of [A-3] and the diamine exemplified as specific examples thereof.

<Liquid crystal alignment film and liquid crystal display element> The liquid crystal alignment agent of the present invention is applied to a substrate, fired, and then subjected to alignment treatment by rubbing treatment or light irradiation, or for some vertical alignment applications. , Can be used as a liquid crystal alignment film without alignment treatment. As the substrate, for example, glass such as floating glass, soda glass, etc.; made of polyethylene terephthalate, polybutylene terephthalate, polypropylene, polystyrene, polyether agglomerate, polycarbonate, etc. , Poly(alicyclic olefin), polyvinyl chloride, polyvinylidene chloride, polyether ether ketone (PEEK) resin film, poly (PSF), polyether (PES), polyamide, polyimide , Acrylic and triacetyl cellulose transparent substrate made of plastics. As the transparent conductive film provided on one side of the substrate, NESA film (registered trademark of PPG Corporation in the United States) made of tin oxide (SnO ₂ ), and indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ) can be used. ITO film, etc.

<Coating film formation process> The coating method of the liquid crystal alignment agent of the present invention is not particularly limited, but there are screen printing, flexographic printing, offset printing, inkjet, dip coating, roll coating, slit coating, spin coating, etc., which can be used according to the purpose . After coating on a substrate by such a method, the solvent is evaporated by heating means such as a hot plate to form a coating film.

The sintering after coating the liquid crystal alignment agent can be carried out at any temperature from 40 to 300°C, but 40 to 250°C is preferred, and 40 to 230°C is more preferred. When using a transparent substrate made of a plastic substrate, the temperature of 40 to 150°C is preferred, and the temperature of 80 to 140°C is preferred. The firing time is preferably 0.1 to 15 minutes, and more preferably 1 to 10 minutes. The thickness of the coating film formed on the substrate is preferably 5 to 1,000 nm, preferably 10 to 500 nm or 10 to 300 nm. The firing can be performed by a hot plate, a hot air circulating furnace, an infrared furnace, or the like.

＜Light irradiation step＞ The light irradiation step in the present invention includes the following steps: for the cured film obtained in the coating film forming step, the first irradiation step in which ultraviolet rays are irradiated from an oblique direction, and the curing after the ultraviolet rays is irradiated The film is subjected to the second irradiation step of ultraviolet irradiation from a direction different from the first irradiation step, and at least one of the first irradiation step and the second irradiation step is separated from the light-shielded area and the The mask of the shading area is performed.

As the light irradiated by the alignment treatment by light irradiation, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be cited. Among these, ultraviolet rays containing light with a wavelength of 300 to 400 nm are preferred. The irradiation light may be polarized light or non-polarized light. As the polarized light, it is preferable to use light containing linear polarized light.

The amount of light irradiation is preferably 0.1 mJ/cm ² or more and less than 1,000 mJ/cm ² , preferably 1 to 500 mJ/cm ² , and more preferably 2 to 200 mJ/cm ² .

The irradiation direction of ultraviolet rays is generally 1° to 89° with respect to the normal to the substrate, preferably 20° to 70°, and particularly preferably 30° to 60°. If the angle is too small, there will be a problem that the pretilt angle becomes smaller, and if it is too large, it will be difficult to design the irradiation device.

As a method of adjusting the irradiation direction to the above-mentioned angle, although there are a method of tilting the substrate itself and a method of tilting the light source, it is preferable from the viewpoint of throughput when the light source itself is tilted.

Furthermore, in the present invention, by using a specific composition, the pretilt angle formed by the irradiation of ultraviolet rays from a certain direction is cancelled by the irradiation of ultraviolet rays from other directions, and different pretilt angles can be formed. By this, for example, after forming a pretilt angle in a specific direction by full-surface exposure of ultraviolet rays, by irradiating ultraviolet rays from other directions through a photomask, it is possible to easily form a plurality of regions with different alignment directions (alignment division). Multi-zone liquid crystal display elements can be manufactured efficiently.

The multi-domain liquid crystal alignment film obtained by the manufacturing method of the present invention is that the pretilt angle has a pretilt angle suitable for vertical alignment mode from 90° tilted from negative 0.1° to negative 10° region 1, and from 90° tilted to Area 2 of positive 0.1°～positive 10° is preferred. That is, as the pretilt angle, it is preferable to have a region 1 of 80° to 89.9° and a region 2 of 90.1° to 100°, and more preferably a region 1 of 85° to 89° and a region 2 of 91° to 95°. good.

In addition, when forming the above-mentioned regions 1 and 2, region 1 may be formed in the first irradiation step, and region 2 may be formed in the second irradiation step, or region 2 may be formed in the first irradiation step and in the second irradiation step. Steps form area 1. When the first irradiation step is not performed through the mask, it is better that the irradiation amount of light in the second irradiation step is greater than the irradiation amount of light in the first irradiation step. On the other hand, when the first irradiation step is performed through a photomask, it is preferable that the irradiation amount of light in the second irradiation step is smaller than the irradiation amount of light in the first irradiation step.

According to the present invention, when the patterned mask is used in both the first irradiation step and the second irradiation step, even if the mask is moved, in the second irradiation area, the tilt of the first irradiation area is cancelled, Since it can be rewritten as the tilt angle of the second irradiation, it will not become a "dark line" when moving the mask.

The liquid crystal display element of the present invention is a multi-domain liquid crystal alignment film used in the present invention, which can be produced by a usual method, and the production method is not particularly limited. The above-mentioned pair of substrates face each other with an appropriate gap in order to make the thickness of the liquid crystal sandwiched between the substrates uniform, and it is preferable to arrange spacers between the substrates. As the spacer, it is possible to use conventional spacers, spacers formed from a composition for forming a photosensitive spacer, and other known spacer materials, or it may be formed on a layer formed of a cured liquid crystal material. The unevenness is used as a spacer.

＜Steps to hold LCD＞ When constructing a liquid crystal cell in which a liquid crystal is sandwiched between substrates, for example, the following two methods can be cited. As a first method, it is possible to make the liquid crystal alignment films face each other, arrange a pair of substrates facing each other via a gap (cell gap), and bond the peripheral portions of the pair of substrates with a sealant. The liquid crystal cell can be manufactured by sealing the injection hole after injecting and filling liquid crystal into the cell gap divided by a suitable sealant on the surface of the substrate.

As the second method, one of the two substrates on which the liquid crystal alignment film is formed can be exemplified at a predetermined location on one of the two substrates. For example, a UV curable sealing material is applied, and the liquid crystal alignment film is further dropped on a predetermined number of places. After the liquid crystal, the other substrates are laminated to make the liquid crystal alignment film face-to-face, and the liquid crystal is spread across the entire substrate. Secondly, after the entire substrate is irradiated with ultraviolet light to harden the sealant, the liquid crystal cell is manufactured (ODF (One Drop Fill) method) ).

As a liquid crystal, it can be used in combination with a fluorine-based liquid crystal or a cyano-based liquid crystal with positive or negative dielectric anisotropy, and a liquid crystal compound or liquid crystal composition polymerized by at least one of heating and light irradiation (Hereinafter also referred to as polymerizable liquid crystal or curable liquid crystal composition) is preferable. For one of the embodiments, the step of forming the coating film of the aforementioned liquid crystal alignment agent can be performed by a roll-to-roll method. When the roll-to-roll method is adopted, the manufacturing steps of the liquid crystal display element can be simplified and the manufacturing cost can be reduced. Then, a liquid crystal display element can be obtained by bonding polarizing plates on both outer sides of the aforementioned liquid crystal cell.

Examples of the polarizing plate used on the outside of the liquid crystal cell include a polarizing film called "H film" that absorbs iodine while aligning polyvinyl alcohol, and a polarizing plate sandwiched by a cellulose acetate protective film. Or a polarizing plate made of the H film itself. As described above, the liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention has good liquid crystal alignment, excellent pretilt angle performance, and high reliability. In addition, the liquid crystal display device manufactured by the method of the present invention has excellent display characteristics. [Example]

The structure of the compound used in the example is shown below. In addition, "t" in the formula means that the cyclohexyl group is in the trans form.

MA-1, MA-2, MA-3, and MA-4 are photo-aligned monomers, and CR-1, CR-2, MOI-BP, HEMA, and MAA are thermally crosslinkable monomers.

X-1, X-2 and X-3 are tetracarboxylic dianhydride monomers.

X-4 is a side chain diamine monomer, and X-5 and X-6 are other diamine monomers.

The abbreviations of the organic solvents used in Examples and the like are as follows. PGME: Propylene glycol monomethyl ether CHN: Cyclohexanone The abbreviations of the polymerization initiators used in Examples and the like are as follows. AIBN: 2,2’-Azobisisobutyronitrile

<Measurement of polymer molecular weight> The molecular weight of the polymer in the synthesis example was measured using a normal temperature gel permeation chromatography (GPC) device (SSC-7200, Shodex) manufactured by Senshu Science Co., Ltd. (KD-803, KD- 805) column temperature was measured as follows: 50 ℃ eluent: DMF (as an additive to, lithium bromide - hydrate _{(LiBr · H 2 O) 30mmol} / L, phosphoric acid anhydrous crystalline · (O- phosphate) 30mmol / L,. THF10ml/L) Flow rate: 1.0ml/min Standard curve preparation standard sample: TSK standard polyethylene oxide manufactured by Tosoh Corporation (molecular weight approximately 9000,000, 150,000, 100,000, 30,000) and polyethylene oxide manufactured by Polymer laboratory Alcohol (molecular weight approximately 12,000, 4,000, 1,000).

＜Reference example 1＞ Dissolve MA-1 (4.95g, 12.0mmol) and MOI-BP (7.04g, 28.0mmol) in CHN (69.8g), use a diaphragm pump to degas, add AIBN (0.33g, 2.0mmol) and proceed again Degas. Thereafter, the reaction was carried out at 55°C for 13 hours to obtain a methacrylate polymer solution. The polymer solution was dropped into a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the resulting precipitate was filtered. This deposit was washed with methanol, and dried under reduced pressure in an oven at 40°C to obtain methacrylate polymer powder (A). The polymer has a number average molecular weight of 44200 and a weight average molecular weight of 141800. CHN (18.0 g) was added to the obtained methacrylate polymer powder (A) (1.5 g), and the mixture was stirred and dissolved at room temperature for 5 hours. CR-1 (0.15g) and PGME (18.0g) were added to the solution and stirred to obtain a liquid crystal alignment agent (A1).

<Example 1-0> [Production of liquid crystal cell] The liquid crystal alignment agent (A1) obtained in Reference Example 1 was spin-coated on the ITO surface of a glass substrate with transparent electrodes made of ITO film at 40°C The hot plate is dried for 300 seconds. Next, firing was performed on a hot plate at 120°C for 10 minutes to form a liquid crystal alignment film with a thickness of 100 nm. Thereafter, in the polarizing plate with the coated surface across the film, the irradiation intensity of the linearly polarized UV 313nm 4.3mW / cm ^2, the direction of the normal of the substrate is inclined at an angle of 40 ° was irradiated 50mJ / cm ^2, to give Substrate with liquid crystal alignment film attached. The irradiated 313nm linearly polarized ultraviolet light is taken out by passing the ultraviolet light emitted from a high-pressure mercury lamp through a 313nm band pass filter and a Brewster polarizer. Two of the above-mentioned substrates were prepared, and a bead spacer of 4 μm was spread on the liquid crystal alignment film of one of the substrates, and then a sealant (manufactured by Mitsui Chemicals, XN-1500T) was applied. Secondly, after bonding another substrate in the irradiation direction of the incident polarized ultraviolet light facing the surface of the liquid crystal alignment film, the irradiation direction of the ultraviolet light entering the opposite substrate is 180°, and then the substrate is bonded at 120°C for 90 minutes. After the sealant is thermally cured, an empty cell is produced. A negative type liquid crystal (MLC-3022 manufactured by Merck & Co.) was injected into the empty cell by a reduced pressure injection method to produce a liquid crystal cell.

[Assessment of pretilt angle] The pretilt angle of the liquid crystal cell was measured by the Mueller matrix method using "AxoScan" manufactured by Axo Metrix. The results are summarized in Table 1.

[Assessment of liquid crystal orientation] After the liquid crystal cell is manufactured, it is subjected to a square phase treatment at 120°C for 1 hour, and the cell is observed in a polarizing microscope to obtain a situation where there is no light loss or poor alignment such as areas, or a uniform liquid crystal drive can be obtained when the voltage is input to the liquid crystal cell The situation is as good as the alignment. The results are summarized in Table 1.

<Example 1-1> For the [Fabrication of liquid crystal cell] of Example 1-0, linearly polarized ultraviolet rays 50mJ/cm ² were irradiated from the normal direction of the substrate at an angle of 40° inclined from the normal direction of the substrate. The liquid crystal cell was obtained by the same method as in Example 1-0 except that the irradiation was performed at an inclined angle of 40° with 50 mJ/cm ² . In addition, the first irradiation and the second irradiation were each inclined at 40° in the opposite direction from the normal direction. In addition, the pretilt angle and the orientation of the liquid crystal cell were evaluated in the same manner as in Example 1-0.

<Examples 1-2, 1-3> For the [Production of liquid crystal cell] of Example 1-1, the second polarized ultraviolet irradiation dose was changed to 100mJ/cm ² (Example 1-2), 150mJ/cm ² Except for (Example 1-3), a liquid crystal cell was obtained by the same method as Example 1-1. In addition, the pretilt angle and the orientation of the liquid crystal cell were evaluated in the same manner as in Example 1-0.

＜Reference example 2＞ Dissolve MA-1 (4.95g, 12.0mmol), MOI-BP (3.52g, 14.0mmol), HEMA (1.82g, 14.0mmol) in CHN (60.2g), use a diaphragm pump to degas, then add AIBN (0.33g, 2.0mmol) degassed again. Thereafter, the reaction was carried out at 55°C for 13 hours to obtain a methacrylate polymer solution. The polymer solution was dropped into a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the resulting precipitate was filtered. This deposit was washed with methanol and dried under reduced pressure in an oven at 40°C to obtain methacrylate polymer powder (B). The number average molecular weight of this polymer was 33,800, and the weight average molecular weight was 123,500. CHN (18.0 g) was added to the obtained methacrylate polymer powder (B) (1.5 g), and the mixture was stirred and dissolved at room temperature for 5 hours. PGME (18.0 g) was added to this solution and stirred to obtain a liquid crystal alignment agent (B1).

＜Reference example 3＞ Dissolve MA-1 (3.30g, 8.0mmol) and MAA (2.75g, 32.0mmol) in CHN (36.2g). After degassing with a diaphragm pump, add AIBN (0.33g, 2.0mmol) and degas again . Then, the reaction was carried out at 55°C for 13 hours to obtain a polymer solution of methacrylate. The polymer solution was dropped into a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the resulting precipitate was filtered. This deposit was washed with methanol, and dried under reduced pressure in an oven at 40°C to obtain methacrylate polymer powder (C). The polymer has a number average molecular weight of 51,500 and a weight average molecular weight of 143,000. CHN (18.0 g) was added to the obtained methacrylate polymer powder (C) (1.5 g), and the mixture was stirred at room temperature for 5 hours to dissolve it. CR-2 (0.45g) and PGME (18.0g) were added to this solution and stirred to obtain a liquid crystal alignment agent (C1).

＜Reference example 4＞ Dissolve X-4 (2.28g, 3.00mmol), X-5 (1.22g, 4.00mmol), X-6 (1.45g, 3.00mmol) and X-1 (2.23g, 6.00mmol) in NMP (27.2g) ), after reacting at 60°C for 5 hours, add X-2 (1.00g, 2.00mmol) and X-3 (0.87g, 2.00mmol) and NMP (9.1g), and react at 40°C for 10 hours. Polyamide acid polymer solution. After adding NMP to the polyamide acid polymer solution (50g) to dilute to 6.5% by mass, adding acetic anhydride (8.8g) and pyridine (2.7g) as the imidization catalyst, and reacting at 75°C for 2.5 hours . The reaction solution was poured into methanol (700 ml), and the resulting precipitate was separated by filtration. The precipitate was washed with methanol, and dried under reduced pressure at 100°C to obtain polyimide polymer powder. The polyimide polymer has an imidization rate of 71%, a number average molecular weight of 13,000, and a weight average molecular weight of 42,000. NMP (44.0 g) was added to the obtained polyimide powder (6.0 g), and the mixture was stirred at 70°C for 20 hours to dissolve it. NMP (10.0g) and BCS (40.0g) were added to this solution, and it stirred at room temperature for 5 hours, and obtained the polyimide polymer solution (H1). The obtained polyimide polymer solution (H1) (14.0 g) and the liquid crystal alignment agent (B1) (6.0 g) obtained in Reference Example 2 were stirred at room temperature for 5 hours to obtain a liquid crystal alignment agent (D1).

＜Reference example 5＞ The polyimide polymer solution (H1) (14.0 g) obtained in Reference Example (4) and the liquid crystal alignment agent (C1) (6.0 g) obtained in Reference Example 3 were stirred at room temperature for 5 hours to obtain a liquid crystal Alignment agent (E1).

<Examples 2-0～5-3> Instead of the liquid crystal alignment agent (A1) obtained in Reference Example 1, the same test as in Examples 1-0 to 1-3 was performed except that the liquid crystal alignment agent described in Table 1 was used. The evaluation results are shown in Table 1.

＜Reference example 6＞ Dissolve MA-2 (13.74g, 24.0mmol) and MA-3 (7.02g, 16.0 mmol) in CHN (119.5g), use a diaphragm pump to degas, add AIBN (0.33g, 2.0mmol) and proceed again Degas. Then, the reaction was carried out at 55°C for 13 hours to obtain a polymer solution of methacrylate. The polymer solution was dropped into a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the resulting precipitate was filtered. This deposit was washed with methanol and dried under reduced pressure in an oven at 40°C to obtain methacrylate polymer powder (D). The polymer has a number average molecular weight of 35,700 and an average molecular weight of 126,000. CHN (18.0 g) was added to the obtained methacrylate polymer powder (D) (1.5 g), and stirred at room temperature for 5 hours to dissolve. CHN (18.0 g) was added to the solution and stirred to obtain a liquid crystal alignment agent (F1).

<Comparative Example 1-0> [Production of Liquid Crystal Cell] The liquid crystal alignment agent (F1) obtained in Reference Example 6 was spin-coated on the ITO surface of a glass substrate with a transparent electrode made of an ITO film at 40°C The heating plate was dried for 300 seconds to form a liquid crystal alignment film with a thickness of 100 nm. A 313nm linearly polarized ultraviolet light with an irradiation intensity of 4.3 mW/cm ² was irradiated to 50 mJ/cm ² at an angle inclined at 40° from the normal direction of the substrate through a polarizing plate on the coating film surface. Next, firing was performed on a hot plate at 120°C for 10 minutes to obtain a substrate with a liquid crystal alignment film. The incoming linearly polarized UV is modulated by passing the ultraviolet light of the high-pressure mercury lamp through a 313nm band pass filter and then passing through a 313nm polarizer. Two of the above-mentioned substrates were prepared, and a 4 μm bead spacer was spread on the liquid crystal alignment film of one substrate, and then a sealant (XN-1500T manufactured by Kyoritsu Chemical Co., Ltd.) was applied. Next, the other substrate was bonded together so that the alignment direction facing the liquid crystal alignment film surface became 180°, and then the sealant was thermally cured at 120°C for 90 minutes to produce empty cells. Negative liquid crystal (Merck & Co., MLC-3022) was injected into the empty cell by a reduced pressure injection method to produce a liquid crystal cell. In addition, the pretilt angle and the orientation of the liquid crystal cell were evaluated by the same method as in Example 1-0.

<Comparative Example 1-1> For the [Production of Liquid Crystal Cell] of Comparative Example 1-0, the normal direction of the free substrate was inclined at an angle of 40°, and the linearly polarized ultraviolet light was irradiated with 50mJ/cm ² to further free the normal direction of the substrate A liquid crystal cell was obtained by the same method as in Comparative Example 1-0 except that the irradiation was performed at an inclined angle of 40° with 50 mJ/cm ² . In addition, the first irradiation and the second irradiation were inclined at 40° in opposite directions from each normal direction. In addition, the pretilt angle and the orientation of the liquid crystal cell were evaluated by the same method as in Example 1-0.

<Comparative Examples 1-2, 1-3> For the [Production of Liquid Crystal Cell] of Comparative Example 1-0, the second polarized ultraviolet irradiation dose was changed to 100mJ/cm ² (Comparative Example 1-2), 150mJ/cm ² Except for (Comparative Example 1-3), a liquid crystal cell was obtained by the same method as Comparative Example 1. In addition, the pretilt angle and the orientation of the liquid crystal cell were evaluated in the same manner as in Example 1-0.

＜Reference example 7＞ Dissolve MA-2 (17.18g, 30.0 mmol) and MAA (1.72g, 20.0 mmol) in NMP (108.51g), degas with a diaphragm pump, add AIBN (0.25g, 1.5mmol) and degas again . Thereafter, the reaction was carried out at 55°C for 13 hours to obtain a methacrylate polymer solution. The polymer solution was dropped into a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the resulting precipitate was filtered. This deposit was washed with methanol and dried under reduced pressure in an oven at 40°C to obtain methacrylate polymer powder (E). The polymer has a number average molecular weight of 22,700 and a weight average molecular weight of 131,000. CHN (18.0 g) was added to the obtained methacrylate polymer powder (E) (1.5 g), and the mixture was stirred at room temperature for 5 hours to be dissolved. CHN (18.0 g) was added to the solution and stirred to obtain a liquid crystal alignment agent (G1).

＜Comparative Examples 2-0～2-3＞ Using the liquid crystal alignment agent (G1) obtained in Reference Example 7, the same test as in Comparative Examples 1-0 to 1-3 was performed except that the firing temperature was changed from 120°C to 150°C.

＜Reference example 8＞ Dissolve MA-4 (4.05g, 8.0mmol) and MAA (2.75g, 32.0mmol) in CHN (28.5g), use a diaphragm pump to degas, add AIBN (0.33g, 2.0mmol) to degas again . Thereafter, the reaction was carried out at 55°C for 13 hours to obtain a methacrylate polymer solution. The polymer solution was dropped into a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the resulting precipitate was filtered. The precipitate was washed with methanol, and dried under reduced pressure in an oven at 40°C to obtain methacrylate polymer powder (H). The polymer has a number average molecular weight of 47,000 and a weight average molecular weight of 140,000. CHN (18.0 g) was added to the obtained methacrylate polymer powder (H) (1.5 g), and the mixture was stirred at room temperature for 5 hours to dissolve it. CR-2 (0.45g) and PGME (18.0g) were added to this solution and stirred to obtain a liquid crystal alignment agent (I1).

＜Reference example 9＞ The polyimide polymer solution (H1) (14.0g) obtained in Reference Example (4) and the liquid crystal alignment agent (I1) (6.0g) obtained in Reference Example (8) were combined at room temperature by performing 5 Stir for hours to obtain a liquid crystal alignment agent (J1).

<Examples 6-0～7-3> Instead of the liquid crystal alignment agent (A1) obtained in Reference Example 1, the same test as in Examples 1-0 to 1-3 was performed except that the liquid crystal alignment agent described in Table 2 was used. The evaluation results are shown in Table 2.

It can be seen from Tables 1 and 2 that in the embodiment, the tilt angle can be changed (rewritten) by the second irradiation, and the liquid crystal alignment after the change is also good. On the other hand, in the comparative example, all tilt angle changes were impossible. [Industrial availability]

According to the manufacturing method of the present invention, a multi-domain liquid crystal alignment film can be efficiently manufactured. In addition, the liquid crystal display element using the obtained multi-domain liquid crystal alignment film can be applied to liquid crystal display elements for ECB and the like.

[Fig. 1] A schematic diagram showing the irradiation step of the present invention. Θ represents the irradiation angle in the first irradiation step, Φ represents the irradiation angle in the second irradiation step, and Ψ represents the tilt angle.

Claims (5)

A method for manufacturing a multi-domain liquid crystal alignment film, characterized in that the method includes the following steps: applying a liquid crystal alignment agent on a substrate, drying and firing to form a cured film, and applying ultraviolet rays to the cured film The first irradiation step in which irradiation is performed in an oblique direction, and the second irradiation step of irradiating ultraviolet rays from a direction different from the irradiation direction in the first irradiation step on the cured film after the ultraviolet irradiation obtained in the first irradiation step. Second irradiation step; At least one of the first irradiation step and the second irradiation step is performed through a mask containing a light-shielded area and an unshielded area, wherein the liquid crystal alignment agent contains: Have (A) the following formula (pa-1)

(In the formula, A is represented by a group selected from fluorine, chlorine, cyano, or an alkoxy group having 1 to 5 carbons, a linear or branched alkyl residue (this is based on Need to be substituted with 1 cyano group or more than 1 halogen atom) substituted pyrimidine-2,5-diyl, pyridine-2,5-diyl, 2,5-thiophene, 2,5-extension Furan, 1,4- or 2,6-naphthylene or phenylene, R ₁ represents a single bond, oxygen atom, -COO- or -OCO-, R ₂ represents a divalent aromatic group, a divalent alicyclic group , A divalent heterocyclic group or a divalent condensed cyclic group, R ₃ is a single bond, an oxygen atom, -COO- or -OCO-, and R ₄ is a linear or branched alkyl group having 1 to 40 carbon atoms or A monovalent organic group containing an alicyclic group with 3 to 40 carbons, D represents an oxygen atom, a sulfur atom or -NR _d- (where R _d represents a hydrogen atom or an alkyl group with 1 to 3 carbons), a represents An integer from 0 to 3, * represents the bonding position) of the polymer of the photo-alignment group and the thermally crosslinkable group A, and a solvent; and the liquid crystal alignment agent is, Z1: the polymer (A) further has heat Crosslinkable group B, and/or Z2: further containing (B) a compound having two or more thermally crosslinkable groups B in the molecule; (thermally crosslinkable group A and thermally crosslinkable group B, each independently selected Free carboxyl group, amino group, alkoxymethyl amide group, hydroxymethyl amide group, hydroxyl group, epoxy moiety-containing group, oxetanyl group, thiopropyl ring group, isocyanate group and blocked isocyanate A group of groups, the thermal crosslinkable group A and the thermal crosslinkable group B can be crosslinked by heat, but the thermal crosslinkable group A and the thermal crosslinkable group B can be the same each other) . The method according to claim 1, wherein at least one of the ultraviolet rays irradiated in the first irradiation step and the second irradiation step is polarized ultraviolet rays. The method according to claim 1, wherein only the second irradiation step is performed via the photomask. A multi-domain liquid crystal alignment film, which is characterized by being formed by using any one of claims 1 to 3. A liquid crystal display element characterized by having a multi-domain liquid crystal alignment film as claimed in claim 4.

Images