KR20210052440A - Manufacturing method of liquid crystal aligning film, liquid crystal aligning film, and liquid crystal display element - Google Patents

Abstract

The present invention provides a simple manufacturing method of a VA mode liquid crystal display element having a plurality of regions having different orientation directions (orientation division) and excellent viewing angle characteristics. The present invention contains a polymer and a solvent having a photoaligning group and a thermal crosslinking group A as component (A), and coating a liquid crystal aligning agent satisfying at least one of the following Z1 and Z2 on a substrate to form a cured film The first irradiation step of irradiating the cured film with ultraviolet rays from an oblique direction, and the second irradiation of irradiating the cured film with ultraviolet rays in a direction different from the first irradiation step A method for producing a multi-domain liquid crystal alignment film, comprising steps in this order, and wherein at least one of the irradiation steps is performed via a mask including a light-shielded region and a light-shielded region.
Z1: The component (A) further has a thermal crosslinkable group B.
Z2: As component (B), further contains a compound having a thermally crosslinkable group B

Description

Manufacturing method of liquid crystal aligning film, liquid crystal aligning film, and liquid crystal display element

The present invention relates to a method for producing a liquid crystal aligning film using a liquid crystal aligning agent, a liquid crystal aligning film obtained thereby, and a liquid crystal display device including the obtained liquid crystal aligning film. More specifically, even when the firing temperature obtained by using a specific liquid crystal aligning agent is low and the firing time is short, the liquid crystal orientation is good, the pretilt angle expression ability is also excellent, and high reliability is obtained. , A liquid crystal alignment film capable of overwriting a pre-tilt angle, and a method for producing a multi-domain liquid crystal alignment film having excellent display quality using a specific liquid crystal aligning agent, a multi-domain liquid crystal alignment film, and a liquid crystal display device.

In a liquid crystal display device, the liquid crystal alignment layer plays a role of aligning the liquid crystal in a certain direction. Currently, the main liquid crystal aligning film used industrially is a polyimide-based liquid crystal aligning agent composed of a polyamic acid (also referred to as polyamic acid), a polyamic acid ester, or a polyimide solution, which is a polyimide precursor, applied to a substrate. And formed by forming a film.

In addition, when the liquid crystal is aligned in parallel or obliquely aligned with respect to the substrate surface, after film formation, a surface stretching treatment by rubbing is further performed.

On the other hand, in the case of aligning the liquid crystal vertically with respect to the substrate (referred to as a vertical alignment (VA) method), a long-chain alkyl, a cyclic group, or a combination of a cyclic group and an alkyl group (see, for example, Patent Document 1), a steroid skeleton ( For example, a liquid crystal alignment film in which a hydrophobic group such as (refer to Patent Document 2) was introduced into the side chain of a polyimide is used. In this case, when a voltage is applied between the substrates and the liquid crystal molecules are tilted in a direction parallel to the substrate, it is necessary to make the liquid crystal molecules tilt from the substrate normal direction toward one direction in the substrate surface. As a means for this, for example, a method of forming a protrusion on a substrate, a method of forming a slit in a display electrode, a method of slightly inclining the liquid crystal molecules from the normal direction of the substrate toward one direction in the surface of the substrate by rubbing (pretilt Method), and furthermore, a method of pretilting a liquid crystal by adding a photopolymerizable compound to the liquid crystal composition in advance, using it with a vertical alignment film such as polyimide, and irradiating ultraviolet rays while applying a voltage to the liquid crystal cell (Example For example, see Patent Document 3) and the like have been proposed.

In recent years, a method of using an anisotropic photochemical reaction by irradiation with polarized ultraviolet rays or the like as an alternative to formation of projections and slits in VA system liquid crystal alignment control, and PSA technology (photoalignment method) has also been proposed. That is, it is known that the tilt direction of the liquid crystal molecules at the time of application of voltage can be uniformly controlled by irradiating polarized ultraviolet rays to a polyimide film having a vertical orientation having photoreactivity and giving the ability to regulate the orientation and the expression of the pretilt angle. Yes (refer to Patent Document 4). Also in this case, like a conventional alignment film, a polyimide liquid crystal alignment film is used, which is excellent in durability and suitable for controlling the pretilt angle of a liquid crystal. It is common that the polyimide liquid crystal aligning film is fired at a high temperature of 200°C or higher.

On the other hand, studies of using a thin and lightweight plastic substrate as a substrate for a liquid crystal display element are also being made energetically. In this case, since the heat resistance of the plastic substrate is low, it is necessary to perform firing at a lower temperature when producing the liquid crystal aligning film. Similarly, it is also desired to reduce the energy cost in manufacturing a liquid crystal display element by making this firing temperature low.

In the case of firing at low temperature, there is a problem that curing must be terminated in a state in which the alignment film material is not sufficiently cured, and it has been difficult to obtain a highly reliable liquid crystal display device (see, for example, Patent Document 5).

On the other hand, the demand for a multi-domain technology that forms a plurality of regions with different orientation directions (orientation division) is increasing, but in the conventional manufacturing method, after exposure using an exposure mask in which a plurality of openings are formed at predetermined intervals, a predetermined It is necessary to reexpose the exposure mask by shifting the exposure mask by an interval, and thus, high precision is required for alignment of the exposure mask and formation of a plurality of openings, the manufacturing process is complicated, and improvement is required. Here, a method of manufacturing a multi-domain liquid crystal display device using a polymer in which a vertical aligning group is bonded to a photodegradable polyimide is known, but a very large amount of light irradiation is required, and the manufacturing efficiency is poor (for example, Patent Document 6, 7 and 8). There are further examples of the method for producing a multi-domain alignment film, but it was not clear what kind of alignment film could be used to implement the invention (for example, see Patent Document 9).

Japanese Laid-Open Patent Publication No. Hei 3-179323 Japanese Patent Laid-Open Publication No. Hei 4-281427 Japanese Patent Publication No. 4504626 Japanese Patent Publication No. 4995267 Japanese Laid-Open Patent Publication No. Hei 7-209633 Japanese Laid-Open Patent Publication No. Hei 11-95224 Japanese Patent Laid-Open Publication No. 2005-148442 Japanese Patent Laid-Open Publication No. 2005-316027 Japanese Unexamined Patent Publication No. 2007-219191

An object of the present invention is to provide a VA mode liquid crystal display device having excellent viewing angle characteristics and a method of manufacturing the same by forming a plurality of regions having different orientation directions (orientation division) more easily with fewer mask processing steps.

In addition, an object of the present invention is to provide an ECB liquid crystal display device having an improved viewing angle characteristic, and a liquid crystal alignment film for the device, in addition to the above object.

The inventors of the present invention have found out the invention with the following <X> as a summary.

<X> (A) A liquid crystal aligning agent which satisfies at least one of the following requirements Z1 and Z2 while containing a polymer and a solvent having a photoalignable group represented by the following formula (pa-1) and a thermal crosslinkable group A as a component Applying on a substrate, drying and firing to form a cured film,

The first irradiation step of irradiating the cured film with ultraviolet rays from an oblique direction, and,

The cured film after ultraviolet irradiation includes a second irradiation step in this order, in which ultraviolet irradiation is performed in a direction different from the first irradiation step,

At least one of the first irradiation step and the second irradiation step is performed via a mask including a light-shielded region and a light-shielded region.

Z1: The polymer which is the component (A) further has a thermal crosslinkable group B.

Z2: As component (B), it further contains a compound having two or more thermally crosslinkable groups B in the molecule.

[Formula 1]

In the formula, A is depending on a group selected from fluorine, chlorine, and cyano as the case may be, or an alkoxy group having 1 to 5 carbon atoms, a linear or branched alkyl moiety (this is optionally one cyano group Or substituted with one or more halogen atoms), substituted with pyrimidine-2,5-diyl, pyridin-2,5-diyl, 2,5-thiophenylene, 2,5-furanylene, 1,4 -Or 2,6-naphthylene or phenylene, R ₁ is a single bond, an oxygen atom, -COO- or -OCO-, and R ₂ is 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 C 1 to C 40 linear or branched alkyl group or an alicyclic group containing 3 to carbon atoms 40 is a monovalent organic group, D represents an oxygen atom, a sulfur atom, or -NR _d- (here, R _d represents a hydrogen atom or an alkyl having 1 to 3 carbon atoms), and a is an integer of 0 to 3 And * represents a bonding position.

The thermally crosslinkable group A and the thermally crosslinkable group B are each independently a carboxyl group, an amino group, an alkoxymethylamide group, a hydroxymethylamide group, a hydroxyl group, an epoxy moiety-containing group, an oxetanyl group, a thiranyl group, an isocyanate group, and a block isocyanate. As an organic group selected from the group consisting of groups, the thermally crosslinkable group A and the thermally crosslinkable group B are selected to undergo a crosslinking reaction by heat, provided that the thermally crosslinkable group A and the thermally crosslinkable group B may be the same as each other.

Advantageous Effects of Invention According to the present invention, it is possible to provide a VA mode liquid crystal display device having excellent viewing angle characteristics by forming a plurality of regions having different orientation directions (orientation division) more easily with fewer mask processing steps.

1 is a schematic diagram showing an 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.

The method for producing a multi-domain liquid crystal aligning film of the present invention contains a polymer and a solvent having a photoalignable group represented by the formula (pa-1) and a thermal crosslinkable group A as the component (A), and the following requirements Z1 and Z2 A process of applying a liquid crystal aligning agent satisfying at least one of the substrates on a 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,

The cured film after ultraviolet irradiation includes a second irradiation step in this order, in which ultraviolet irradiation is performed in a direction different from the first irradiation step,

At least one of the first irradiation step and the second irradiation step is performed via a mask including a light-shielded region and a light-shielded region.

Z1: The polymer which is the component (A) further has a thermal crosslinkable group B.

Z2: As component (B), it further contains a compound having two or more thermally crosslinkable groups B in the molecule.

The thermally crosslinkable group A and the thermally crosslinkable group B are each independently a carboxyl group, an amino group, an alkoxymethylamide group, a hydroxymethylamide group, a hydroxyl group, an epoxy moiety-containing group, an oxetanyl group, a thiranyl group, an isocyanate group, and a block isocyanate. As an organic group selected from the group consisting of groups, the thermally crosslinkable group A and the thermally crosslinkable group B are selected to undergo a crosslinking reaction by heat, provided that the thermally crosslinkable group A and the thermally crosslinkable group B may be the same as each other.

Here, ``two or more in a molecule'' means, for example, in the case of containing two or more groups of the same type, such as two or more epoxy groups, in the molecule, for example, a combination of an epoxy group and a thirane group, such as a heterogeneous ( It means to include the case of containing two or more groups in total in the molecule of (異種). "Two or more in a molecule" preferably contains two or more groups of the same kind in a molecule.

Since the polymer which is the component (A) contained in the liquid crystal aligning agent of the present invention has high sensitivity to light, the orientation control ability can be expressed even in polarized ultraviolet irradiation at a low exposure amount.

In addition, when the polymer as the component (A) contains a thermal crosslinkable group A and further contains a thermal crosslinkable group B in the component, even when the sintering time of the liquid crystal aligning agent is short, the polymer as the component (A) is included. Crosslinking reaction becomes possible. Accordingly, when the photo-alignment site exhibits anisotropy by photoreaction, since anisotropy remains (memory) in the liquid crystal alignment film easily, it becomes possible to increase the liquid crystal alignment and further express the pretilt angle of the liquid crystal.

In addition, the moiety having a photoalignable group represented by the above formula (pa-1) (for example, a group represented by the formula (a-1) described later), the thermal crosslinkable group A and the thermal crosslinkable group B are all in the polymer. Since it can be a side chain, it can also be referred to as a "side chain" if necessary.

Hereinafter, each constitutional requirement of the present invention will be described in detail.

<(A) component: Specific polymer>

[Photo-aligning group represented by formula (pa-1)]

In the present invention, the moiety in the molecule having photoalignment represented by the above formula (pa-1) can be represented by, for example, the following formula (a-1). Moreover, although the structure derived from a monomer represented by the following formula (a-1-m) is mentioned as the site|part, it is not limited to this. In the formula, Ia is a monovalent organic group represented by the following formula (pa-1).

[Formula 2]

In formula (pa-1), A is optionally according to a group selected from fluorine, chlorine, and cyano, or an alkoxy group having 1 to 5 carbon atoms, a linear or branched alkyl residue (this is Thus substituted with one cyano group or one or more halogen atoms), substituted with pyrimidine-2,5-diyl, pyridin-2,5-diyl, 2,5-thiophenylene, 2,5-fura Represents nylene, 1,4- or 2,6-naphthylene or phenylene, R ₁ is a single bond, an oxygen atom, -COO- or -OCO-, and R ₂ is a divalent aromatic group, a divalent alicyclic group, Is 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 or alicyclic group having 1 to 40 carbon atoms Is a monovalent organic group containing 3 to 40 carbon atoms, D represents an oxygen atom, a sulfur atom, or -NR _d- (here, R _d represents a hydrogen atom or an alkyl having 1 to 3 carbon atoms), and a represents It is an integer of 0-3, and * represents the bonding position with _{S a.}

In the formula (a-1) or (a-1-m), S _a represents a spacer unit, and _{the linking group on the left of S a} is optionally interposed with a spacer in the main chains of the first and second specific polymers. To indicate binding.

S _a can be represented by the structure of the following formula (Sp), for example.

[Formula 3]

In formula (Sp),

The bond on the left side of W ₁ represents the bond to _{M b,}

The bond on the right side of W ₃ represents the bond to _{I a,}

W ₁ , W ₂ and W ₃ are each independently a single bond, a divalent heterocycle, -(CH ₂ ) _n- (wherein n represents 1 to 20), -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -CH=CH-, -CF=CF-, -CF ₂ O-, -OCF ₂ -, -CF ₂ CF ₂ -or -C≡C-, In these substituents, at least one of the non-adjacent CH ₂ groups is 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- (in the formula, R independently represents hydrogen or a linear or branched alkyl group having 1 to 5 carbon atoms),

A ₁ and A ₂ are each independently a group selected from a single bond, a divalent alkyl group, a divalent aromatic group, a divalent alicyclic group, or a divalent heterocyclic group, and each group is unsubstituted or one or more The hydrogen atom may be substituted with a fluorine atom, a chlorine atom, a cyano group, a methyl group, or a methoxy group.

In formula (a-1-m), M _a represents a polymerizable group. As the polymerizable group, radical polymerizable groups of (meth)acrylate, fumarate, maleate, α-methylene-γ butyrolactone, styrene, vinyl, maleimide, norbornene, (meth)acrylamide and derivatives thereof, And siloxane. Preferably, they are (meth)acrylate, α-methylene-γ butyrolactone, styrene, vinyl, maleimide, and acrylamide.

r is an integer satisfying 1≦r≦3.

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

As _{the aromatic group for A 1} , A ₂ , and M _b , for example, an aromatic hydrocarbon having 6 to 18 carbon atoms such as benzene, biphenyl, and naphthalene can be mentioned. As _{the alicyclic group in A 1} , A ₂ , and M _b , for example, alicyclic hydrocarbons having 6 to 12 carbon atoms such as cyclohexane and bicyclohexane are mentioned. Examples of the heterocycle in A ₁ , A ₂ , and M _b include nitrogen-containing hetero rings such as pyridine, piperidine, and piperazine. Examples of the alkyl group for A ₁ and A ₂ include a linear or branched alkyl group having 1 to 10 carbon atoms.

From the viewpoint of being able to express good vertical orientation control ability and stable pretilt angle, as the structure of (a-1), the group represented by the above (pa-1) or the group represented by the following (pa-1-a) Can be lifted. Moreover, although the structure derived from the monomer represented by the following formula (pa-1-ma) is mentioned as the site|part, it is not limited to this.

[Formula 4]

In formula (pa-1-a) or (pa-1-ma), M _a , M _b , and S _a are the same definitions as described 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 C 3 to C 40 monovalent organic group including a C 1 to C 40 linear or branched alkyl group or an alicyclic group.

R ₅ is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine atom or a cyano group, 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 formula (pa-1-a) or (pa-1-ma), S _a is a linear or branched alkylene group having 1 to 10 carbon atoms, which is a linear or branched alkylene group having 1 to 8 carbon atoms. It is preferable and, for example, methylene group, ethylene group, n-propylene group, n-butylene group, t-butylene group, n-pentylene group, n-hexylene group, n-heptylene group, n-octylene group are preferable. Do.

As the divalent aromatic group of S _a , for example, 1,4-phenylene group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group, 2,3,5,6 -A tetrafluoro-1,4-phenylene group, etc. are mentioned.

Examples of the divalent alicyclic group of S _a include trans-1,4-cyclohexylene, trans-trans-1,4-bicyclohexylene, and the like.

As the _{divalent heterocyclic group of S a} , for example, 1,4-pyridylene group, 2,5-pyridylene group, 1,4-furanylene group, 1,4-piperazine group, 1,4-p Peridingi, etc. are mentioned.

S _a is preferably an alkylene group having 1 to 8 carbon atoms, more preferably an alkylene group having 1 to 6 carbon atoms, more preferably an alkylene group having 1 to 4 carbon atoms.

As the divalent aromatic group of R ₂ , for example, 1,4-phenylene group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group, 2,3,5,6 -A tetrafluoro-1,4-phenylene group, a naphthylene group, etc. are mentioned.

Examples of the divalent alicyclic group for R ₂ include trans 1,4-cyclohexylene and trans-trans-1,4-bicyclohexylene.

As the _{divalent heterocyclic group of R 2} , for example, 1,4-pyridylene group, 2,5-pyridylene group, 1,4-furanylene group, 1,4-piperazine group, 1,4-pi Peridingi, etc. are mentioned.

R ₂ is preferably a 1,4-phenylene group, trans1,4-cyclohexylene, or trans-trans-1,4-bicyclohexylene.

As _{a C1-C40 linear or branched alkyl group of R 4} , for example, a C1-C20 linear or branched alkyl group may be exemplified, and some or all of the hydrogen atoms of this alkyl group are fluorine atoms. You may be substituted by. Examples of such an alkyl group include, for example, methyl group, ethyl group, n-propyl group, n-butyl group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n- Nonyl group, n-decyl group, n-lauryl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n -Octadecyl group, n-nonadecyl group, n-eicosyl group, 4,4,4-trifluorobutyl group, 4,4,5,5,5-pentafluoropentyl group, 4,4,5, 5,6,6,6-heptafluorohexyl group, 3,3,4,4,5,5,5-heptafluoropentyl group, 2,2,2-trifluoroethyl group, 2,2,3 ,3,3-pentafluoropropyl group, 2-(perfluorobutyl)ethyl group, 2-(perfluorooctyl)ethyl group, 2-(perfluorodecyl)ethyl group, and the like.

As _{a C3-C40 monovalent organic group containing an alicyclic group of R 4} , for example, a cholesteryl group, a cholestanyl group, an adamantyl group, the following formula (Alc-1) or (Alc-2) (in the formula , R ₇ is a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 20 carbon atoms, respectively, the alkyl group having 1 to 20 carbon atoms may be substituted with a fluorine atom, and * represents a bonding position). .

[Formula 5]

Examples of the monomer represented by the above formula (pa-1-ma) include structures represented by the formulas (paa-1-ma1) to (paa-1-ma18), but are not limited thereto. In addition, in the formula, "E" represents an E chain, and "t" represents that a cyclohexyl group is trans-type.

[Formula 6]

[Formula 7]

[Thermal crosslinking machine A and the thermal crosslinking machine B]

The thermally crosslinkable group A and the thermally crosslinkable group B are each independently a carboxyl group, an amino group, an alkoxymethylamide group, a hydroxymethylamide group, a hydroxyl group, an epoxy moiety-containing group, an oxetanyl group, a thiranyl group, an isocyanate group, and a block isocyanate. As an organic group selected from the group consisting of groups, the thermally crosslinkable group A and the thermally crosslinkable group B are selected to undergo a crosslinking reaction by heat, provided that the thermally crosslinkable group A and the thermally crosslinkable group B may be the same as each other.

As such a combination of the thermally crosslinkable group A and the thermally crosslinkable group B, one is a carboxyl group, the other is an epoxy group, an oxetanyl group, or a thiranyl group, a combination wherein one is a hydroxy group, and the other is a block isocyanate group, A combination in which one is a phenolic hydroxy group, the other is an epoxy group, an oxetanyl group, or a thiranyl group, a combination in which one is a carboxyl group and the other is a block isocyanate group, a combination in which one is an amino group, and the other is a block isocyanate group, both together And combinations that are N-alkoxymethylamides. A more preferable combination is a carboxyl group and an epoxy group, a hydroxy group and a block isocyanate group.

In order to introduce such a thermally crosslinkable group A into the polymer which is the component (A), a monomer having a thermally crosslinkable group A may be copolymerized.

Further, when the liquid crystal aligning agent used in the present invention satisfies the requirement Z1, when producing the polymer as the component (A), both a monomer having a thermally crosslinkable group A and a monomer having a thermally crosslinkable group B may be copolymerized.

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

2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate , 2,3-dihydroxypropyl acrylate, 2,3-dihydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, caprolactone 2-(acryloyloxy) ethyl Ester, caprolactone 2-(methacryloyloxy) ethyl ester, poly(ethylene glycol) ethyl ether acrylate, poly(ethylene glycol) ethyl ether methacrylate, 5-acryloyloxy-6-hydroxynorbor Monomers having a hydroxyl group such as ene-2-carboxylic-6-lactone and 5-methacryloyloxy-6-hydroxynorbornene-2-carboxylic-6-lactone;

Phenolic hydrodes such as hydroxystyrene, N-(hydroxyphenyl)methacrylamide, N-(hydroxyphenyl)acrylamide, N-(hydroxyphenyl)maleimide, and N-(hydroxyphenyl)maleimide A monomer having a oxy group;

Monomers having an amino group such as aminoethyl acrylate, aminoethyl methacrylate, aminopropyl acrylate, and aminopropyl methacrylate;

Hydroxymethyl group or alkoxy such as N-hydroxymethyl (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, and N-butoxymethyl (meth)acrylamide (Meth)acrylamide compound substituted with a methyl group;

Allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, 2-methylglycidyl methacrylate, α-ethylglycidyl acrylate, α-n-propyl glycidyl acrylate, α-n- Glycidyl butyl acrylate, 3,4-epoxybutyl acrylate, 3,4-epoxybutyl methacrylic acid, 6,7-epoxyheptyl methacrylate, 6,7-epoxyheptyl methacrylate, α-ethylacrylic acid-6,7 -Epoxyheptyl, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, methacrylic acid 3,4-epoxycyclohexylmethyl, 3-ethenyl-7- Monomers having an epoxy moiety-containing group such as oxabicyclo[4.1.0]heptane, 1,2-epoxy-5-hexene, and 1,7-octadiene monoepoxide;

3-(acryloyloxymethyl)oxetane, 3-(acryloyloxymethyl)-2-methyloxetane, 3-(acryloyloxymethyl)-3-ethyloxetane, 3-(acryloyl Oxymethyl)-2-trifluoromethyloxetane, 3-(acryloyloxymethyl)-2-pentafluoroethyloxetane, 3-(acryloyloxymethyl)-2-phenyloxetane, 3- (Acryloyloxymethyl)-2,2-difluorooxetane, 3-(acryloyloxymethyl)-2,2,4-trifluorooxetane, 3-(acryloyloxymethyl)- 2,2,4,4-tetrafluorooxetane, 3-(2-acryloyloxyethyl)oxetane, 3-(2-acryloyloxyethyl)-2-ethyloxetane, 3-(2 -Acryloyloxyethyl)-3-ethyloxetane, 3-(2-acryloyloxyethyl)-2-trifluoromethyloxetane, 3-(2-acryloyloxyethyl)-2-penta Fluoroethyloxetane, 3-(2-acryloyloxyethyl)-2-phenyloxetane, 3-(2-acryloyloxyethyl)-2,2-difluorooxetane, 3-(2 Acrylic acid esters such as -acryloyloxyethyl)-2,2,4-trifluorooxetane and 3-(2-acryloyloxyethyl)-2,2,4,4-tetrafluorooxetane; 3-(methacryloyloxymethyl)oxetane, 3-(methacryloyloxymethyl)-2-methyloxetane, 3-(methacryloyloxymethyl)-3-ethyloxetane, 3-( Methacryloyloxymethyl)-2-trifluoromethyloxetane, 3-(methacryloyloxymethyl)-2-pentafluoroethyloxetane, 3-(methacryloyloxymethyl)-2- Phenyloxetane, 3-(methacryloyloxymethyl)-2,2-difluorooxetane, 3-(methacryloyloxymethyl)-2,2,4-trifluorooxetane, 3- (Methacryloyloxymethyl)-2,2,4,4-tetrafluorooxetane, 3-(2-methacryloyloxyethyl)oxetane, 3-(2-methacryloyloxyethyl) -2-ethyloxetane, 3-(2-methacryloyloxyethyl)-3-ethyloxetane, 3-(2-methacryloyloxyethyl)-2-trifluoromethyloxetane, 3- (2-methacryloyloxyethyl)-2-pentafluoroethyloxetane, 3-(2-methacryloyloxyethyl)-2-phenyloxetane, 3-(2-methacryloyloxyethyl) )-2,2-difluorooxetane, 3-(2-methacryloyloxyethyl)-2,2,4-trifluorooxetane, 3-(2-methacryloyloxyethyl)- Monomers having an oxetanyl group such as 2,2,4,4-tetrafluorooxetane;

2,3-epithiopropylacrylate or methacrylate, and 2- or 3- or 4-(β-epithiopropylthiomethyl)styrene, 2- or 3- or 4-(β-epithiopropyloxymethyl ) A monomer having a thiranyl group such as styrene, 2- or 3- or 4-(β-epithiopropylthio) styrene, and 2- or 3- or 4-(β-epithiopropyloxy) styrene;

Acrylic acid 2-(0-(1'-methylpropylideneamino)carboxyamino)ethyl, acrylic acid 2-(3,5-dimethylpyrazolyl)carbonylamino)ethyl, methacrylic acid 2-(0-(1'-) Monomers having a block isocyanate group such as methylpropylideneamino)carboxyamino)ethyl and 2-(3,5-dimethylpyrazolyl)carbonylamino)ethyl methacrylate; And the like. In addition, (meth)acrylamide means both acrylamide and methacrylamide.

In addition, in the present invention, when obtaining a specific copolymer, in addition to the monomer having a photoalignable group represented by the formula (a-1-m) and a monomer having a thermal crosslinkable group A and optionally a thermal crosslinkable group B, these monomers Other monomers that can be copolymerized with may be used in combination.

Specific examples of such other monomers include acrylic acid ester compounds, methacrylic acid ester compounds, maleimide compounds, acrylonitrile, maleic anhydride, styrene compounds, vinyl compounds, N-methoxymethyl (meth)acrylamide, N- And a monomer having a nitrogen-containing aromatic heterocyclic group and a polymerizable group, such as acrylamide compounds such as butoxymethyl (meth)acrylamide and acrylamide.

As an acrylic acid ester compound, for example, methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthryl acrylate, anthryl methyl acrylate, phenyl acrylate, 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-tricyclodecylacrylic Rate, and 8-ethyl-8-tricyclodecylacrylate, etc. are mentioned.

As a methacrylic acid ester compound, for example, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, hexadecyl methacrylate, octadecyl methacrylate, benzyl methacrylate, naphthyl methacrylate , Anthryl methacrylate, anthryl methyl methacrylate, phenyl methacrylate, 2,2,2-trifluoroethyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate Acrylate, 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, and 8-ethyl-8-tricyclodecyl methacrylate And the like.

Examples of the (meth)acrylic acid amide compound include acrylamide, methacrylamide, N-methylacrylamide, N,N-dimethylacrylamide, and N,N-diethylacrylamide.

Examples of the vinyl compound include methyl vinyl ether, benzyl vinyl ether, vinyl naphthalene, vinyl carbazole, allyl glycidyl ether, and 3-ethenyl-7-oxabicyclo[4.1.0] heptane, and the like. Can be lifted.

Examples of the styrene compound include styrene, methylstyrene, chlorostyrene, and bromostyrene.

Examples of the maleimide compound include maleimide, N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide.

The nitrogen-containing aromatic heterocycle has at least one structure selected from the group consisting of the following formulas [Na] to [Nb] (in the formula, Z ₂ is a linear or branched alkyl group having 1 to 5 carbon atoms), preferably It is preferable that it is an aromatic cyclic hydrocarbon containing 1-4 pieces.

[Formula 8]

Specifically, oxazole ring, thiazole ring, pyridine ring, pyrimidine ring, quinoline ring, 1-pyrazoline ring, isoquinoline ring, thiadiazole ring, pyridazine ring, triazine ring, pyrazine ring, phenanthrol And a lean ring, a quinoxaline ring, a benzothiazole ring, an oxadiazole ring, an acridine ring, and the like. Further, the carbon atom of these nitrogen-containing aromatic heterocycles may have a substituent containing a hetero atom. Among these, a pyridine ring is mentioned, for example.

As a monomer having a nitrogen-containing aromatic heterocyclic group and a polymerizable group, for example, 2-(2-pyridylcarbonyloxy)ethyl (meth)acrylate, 2-(3-pyridylcarbonyloxy)ethyl (meth) Acrylate, 2-(4-pyridylcarbonyloxy)ethyl (meth)acrylate, and the like.

Other monomers used in the present invention may be used singly or in combination of two or more kinds of monomers.

The photoreactive moiety represented by the formula (pa-1) to be contained in the polymer of the present invention may be used singly or in combination of two or more moieties.

The photoreactive moiety represented by the above formula (pa-1) is contained in a ratio of 5 to 50 mol%, 10 to 40 mol%, or 15 to 35 mol% of all repeating units of the polymer as component (A). desirable.

As the moiety having a thermal crosslinkable group to be contained in the polymer of the present invention, the thermal crosslinkable group A may be used alone, or two or more types of moieties including the thermal crosslinkable group A and the thermal crosslinkable group B may be used in combination.

It is preferable that the introduction amount of the moiety having a thermally crosslinkable group is 50 to 95 mol%, 60 to 90 mol%, or 65 to 85 mol% of all repeating units of the polymer which is the component (A).

It is preferable that content of the structure derived from the said other monomer contains 0 to 40 mol%, 0 to 30 mol%, or 0 to 20 mol% of all repeating units of the polymer which is a component (A).

<Method for producing a specific polymer>

The specific polymer of component (A) contained in the liquid crystal aligning agent of the present invention is a monomer having a photoalignable group represented by the above formula (pa-1), a monomer having the above thermal crosslinkable group A, and, if desired, the above It is obtained by copolymerizing a monomer having a thermally crosslinkable group B of. In addition, it can be copolymerized with the above other monomers.

The method for producing the specific polymer of the component (A) in the present invention is not particularly limited, and a general-purpose method handled industrially can be used. Specifically, it can be produced by cationic polymerization, radical polymerization, or anionic polymerization using a vinyl group of a monomer. Among these, radical polymerization is particularly preferred from the viewpoint of easiness of reaction control and the like.

As the polymerization initiator for radical polymerization, known compounds such as a radical polymerization initiator and a reversible addition-cleavage 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. Examples of such radical thermal polymerization initiators include ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), diacyl peroxides (acetyl peroxide, benzoyl peroxide, etc.), and hydroperoxides. (Hydrogen peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxy ketals (dibutyl Peroxycyclohexane, etc.), alkyl peresters (peroxyneodecanoic acid-tert-butyl ester, peroxypivalic acid-tert-butyl ester, peroxy 2-ethylcyclohexanoic acid-tert-amyl ester, etc.), and Sulfates (potassium persulfate, sodium persulfate, ammonium persulfate, etc.), azo compounds (azobisisobutyronitrile, and 2,2'-di(2-hydroxyethyl)azobisisobutyronitrile, etc.) Can be lifted.

Such radical thermal polymerization initiators may be used alone or in combination of two or more.

The radical photopolymerization initiator is not particularly limited as long as it is a compound that initiates radical polymerization by irradiation with light. Examples of such radical photopolymerization initiators include known compounds such as benzophenone, Michler's ketone, 4,4'-bis(diethylamino)benzophenone, xanthone, thioxanthone, and isopropylxanthone. . These compounds may be used alone or in combination of two or more.

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, and the like can be used.

The solvent used in the polymerization reaction of the specific polymer of the component (A) is not particularly limited as long as the resulting polymer is dissolved. As a specific example, the solvent described in the item of <solvent> mentioned later, for example, N-alkyl-2-pyrrolidones, dialkylimidazolidinones, lactones, carbonates, ketones, formula (Sv- The compound represented by 1) and the compound represented by formula (Sv-2), tetrahydrofuran, 1,4-dioxane, dimethyl sulfone, dimethyl sulfoxide, etc. are mentioned.

These solvents may be used alone or in combination. Moreover, even if it is a solvent which does not dissolve the produced|generated polymer, you may mix and use with the above-mentioned solvent within the range in which the produced|generated polymer does not precipitate.

Further, in radical polymerization, since oxygen in the solvent becomes a cause of inhibiting the polymerization reaction, it is preferable to use the organic solvent degassed to the extent possible.

The polymerization temperature at the time of radical polymerization can be selected from an arbitrary temperature of 30 to 150°C, but is preferably in the range of 50 to 100°C. Moreover, although the reaction can be carried out at an arbitrary concentration, the monomer concentration is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. It is carried out at a high concentration at the beginning of the reaction, and after that, an organic solvent can be added.

In the above-described radical polymerization reaction, if the ratio of the radical polymerization initiator is large with respect to the monomer, the molecular weight of the obtained polymer decreases, and if the ratio of the radical polymerization initiator is small, the molecular weight of the obtained polymer increases. It is preferable that it is mol%. In addition, at the time of polymerization, various monomer components, solvents, initiators, and the like can also be added.

[Recovery of Polymer]

In the case of recovering the produced polymer from the reaction solution obtained by the above-described reaction, the reaction solution may be added to a poor solvent to precipitate these polymers. Examples of poor solvents used for precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, heptane, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, and water. The polymer injected into the poor solvent and precipitated can be collected by filtration and then dried at room temperature or heated under normal pressure or reduced pressure. Further, if the polymer recovered by precipitation is re-dissolved in an organic solvent and the operation of reprecipitating and recovering is repeated 2 to 10 times, impurities in the polymer can be reduced. Examples of the poor solvent at this time include alcohols, ketones, hydrocarbons, and the like, and the use of three or more poor solvents selected from among them is preferable because the efficiency of purification is further increased.

The molecular weight of the specific polymer of component (A) is the weight average molecular weight measured by GPC (Gel Permeation Chromatography) when the strength of the resulting coating film, workability during coating film formation, and uniformity of the coating film are considered. This is preferable, and more preferably, it is 5000 to 100000.

<(B) component>

When the liquid crystal aligning agent used for this invention satisfies the requirement Z2, it contains a crosslinking agent as (B) component. As the component (B), a crosslinking agent having two or more thermal crosslinkable groups B is exemplified.

Examples of the crosslinking agent as component (B) include an epoxy compound, a compound having two or more amino groups, a methylol compound, an isocyanate compound, a phenoplast compound, a low molecular weight compound such as a block isocyanate compound, a polymer of N-alkoxymethylacrylamide, and an epoxy group. And polymers such as polymers of compounds having an isocyanate group and polymers of compounds having an isocyanate group.

As specific examples of the above-described epoxy compound, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglyci Dyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3 ,5,6-tetraglycidyl-2,4-hexanediol, N,N,N',N',-tetraglycidyl-m-xylenediamine, 1,3-bis(N,N-di Glycidylaminomethyl)cyclohexane, and N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, and the like.

Examples of the compound having two or more amino groups include diamines such as alicyclic diamine, aromatic diamine, aromatic-aliphatic diamine, and aliphatic diamine.

Examples of alicyclic diamines include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 4,4'-diamino-3,3' -Dimethyldicyclohexylamine, isophoronediamine, etc. are mentioned.

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

Examples of the aromatic-aliphatic diamine include 3-aminobenzylamine, 4-aminobenzylamine, 3-amino-N-methylbenzylamine, 4-amino-N-methylbenzylamine, 3-aminophenethylamine, 4-amino Phenethylamine, 3-amino-N-methylphenethylamine, 4-amino-N-methylphenethylamine, 3-(3-aminopropyl)aniline, 4-(3-aminopropyl)aniline, 3-(3 -Methylaminopropyl)aniline, 4-(3-methylaminopropyl)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-aminonaphthyl)methylamine, 3-(6-aminonaphthyl)methylamine, 2-(6-aminonaphthyl)ethylamine, 3-(6-aminonaphthyl)ethylamine, etc. Can be mentioned.

Examples of aliphatic diamines include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 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-dimethylheptane, 1,7-diamino-4,4-dimethylheptane, 1,7-diamino-3-methylheptane, 1, And 9-diamino-5-methylheptane.

Specific examples of the methylol compound include compounds such as alkoxymethylated glycoluril, alkoxymethylated benzoguanamine, and alkoxymethylated melamine.

Specific examples of the alkoxymethylated glycoluril include, for example, 1,3,4,6-tetrakis (methoxymethyl) glycoluril, 1,3,4,6-tetrakis (butoxymethyl) glycoluril, 1,3,4,6-tetrakis (hydroxymethyl) glycoluril, 1,3-bis (hydroxymethyl) urea, 1,1,3,3-tetrakis (butoxymethyl) urea, 1,1 ,3,3-tetrakis(methoxymethyl)urea, 1,3-bis(hydroxymethyl)-4,5-dihydroxy-2-imidazolinone, and 1,3-bis(methoxymethyl) )-4,5-dimethoxy-2-imidazolinone, etc. are mentioned. As a commercial product, Mitsui Cytec Co., Ltd. manufactured glycoluril compound (trade name: Cymel (registered trademark) 1170, powder link (registered trademark) 1174), and other compounds, methylated urea resin (trade name: UFR (registered trademark) 65), butyl Huaurea resin (brand name: UFR (registered trademark) 300, U-VAN10S60, U-VAN10R, U-VAN11HV), DIC Co., Ltd. urea/formaldehyde resin (high condensation type, brand name: Beccamin (registered trademark)) J-300S, same P-955, same N), etc. are mentioned.

As a specific example of alkoxymethylated benzoguanamine, tetramethoxymethylbenzoguanamine etc. are mentioned, for example. As a commercial product, manufactured by Mitsui Cytec Co., Ltd. (brand name: Cymel (registered trademark) 1123), manufactured by Sanwa Chemical Co., Ltd. (brand name: Nikarak (registered trademark) BX-4000, BX-37, BL-60, BX-55H), etc. are mentioned.

As a specific example of an alkoxymethylated melamine, hexamethoxymethylmelamine etc. are mentioned, for example. As a commercial product, Mitsui Cytec Co., Ltd. methoxymethyl type melamine compound (trade name: Cymel (registered trademark) 300, copper 301, copper 303, copper 350), butoxymethyl type melamine compound (trade name: Mycoat (registered trademark) ) 506, copper 508), Sanwa Chemical methoxymethyl type melamine compound (trade name: Nikarak (registered trademark) MW-30, copper MW-22, copper MW-11, copper MS-001, copper MX-002, copper MX-730, MX-750, MX-035), butoxymethyl type melamine compound (trade name: Nikarak (registered trademark) MX-45, MX-410, MX-302), and the like.

Further, a compound obtained by condensing a melamine compound, a urea compound, a glycoluril compound, and a benzoguanamine compound in which the hydrogen atom of such an amino group is substituted with a methylol group or an alkoxymethyl group may be used. For example, a high molecular weight compound prepared from a melamine compound and a benzoguanamine compound described in US Patent Publication No. 623310 may be mentioned. As a commercial product of the melamine compound, a brand name: Cymel (registered trademark) 303 (manufactured by Mitsui Cytec Co., Ltd.) may be mentioned, and as a commercial product of the benzoguanamine compound, a brand name: Cymel (registered trademark) 1123 (Mitsui Cytec Co., Ltd. product), etc. are mentioned.

Specific examples of the isocyanate compound include, for example, VESTANAT B1358/100, VESTAGON BF 1540 (above, isocyanurate-type modified polyisocyanate, manufactured by Degusa Japan Co., Ltd.), Takenate (registered trademark) B-882N. , Copper B-7075 (above, isocyanurate-type modified polyisocyanate, manufactured by Mitsui Chemical Co., Ltd.), etc. are mentioned.

Specific examples of the phenoplast compound include the following compounds, but the phenoplast compound is not limited to the following compound examples.

[Formula 9]

Specific examples of the compound having two or more hydroxyalkylamide groups at the molecular terminal include, for example, the following compounds, Primid XL-552, and Primid SF-4510.

[Formula 10]

As a block isocyanate compound, for example, Collonate AP stable M, Collonate 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (above, manufactured by Nippon Polyurethane Co., Ltd.), Takenate B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N (above, manufactured by Mitsui Chemical Co., Ltd.), etc. are mentioned.

In addition, as the polymer of the N-alkoxymethylacrylamide described above, for example, N-hydroxymethyl (meth)acrylamide, N-methoxymethyl (meth)acrylamide, and N-ethoxymethyl (meth) And polymers prepared using an acrylamide compound or a methacrylamide compound substituted with a hydroxymethyl group or alkoxymethyl group such as acrylamide and N-butoxymethyl (meth)acrylamide.

Specific examples of such a polymer include, for example, poly(N-butoxymethylacrylamide), a copolymer of N-butoxymethylacrylamide and styrene, and of N-hydroxymethylmethacrylamide and methylmethacrylate. Copolymers, copolymers of N-ethoxymethyl methacrylamide and benzyl methacrylate, and copolymers of N-butoxymethylacrylamide and benzyl methacrylate and 2-hydroxypropyl methacrylate. . The weight average molecular weight of such a polymer is 1,000 to 200,000, more preferably 3,000 to 150,000, and still more preferably 3,000 to 50,000.

As the polymer of the compound having an epoxy group, for example, a compound having an epoxy group such as glycidyl methacrylate, 3,4-epoxycyclohexylmethylmethacrylate, and 3,4-epoxycyclohexylmethylmethacrylate And polymers produced by using.

Specific examples of such a polymer include, for example, poly(3,4-epoxycyclohexylmethyl methacrylate), poly(glycidyl methacrylate), glycidyl methacrylate and methyl methacrylate. Coalescence, a copolymer of 3,4-epoxycyclohexylmethyl methacrylate and methyl methacrylate, a copolymer of glycidyl methacrylate and styrene, and the like. The weight average molecular weight of such a polymer is 1,000 to 200,000, more preferably 3,000 to 150,000, and still more preferably 3,000 to 50,000.

As the polymer of the compound having an isocyanate group described above, for example, 2-isocyanatoethyl methacrylate (Carenz MOI [registered trademark], manufactured by Showa Electric Co., Ltd.), 2-isocyanatoethylacrylic A compound having an isocyanate group, such as a rate (Carenz AOI [registered trademark], manufactured by Showa Electric Co., Ltd.), or 2-(0-[1'-methylpropylideneamino]carboxyamino)ethyl methacrylate (Carenz MOI-BM [registered trademark], manufactured by Showa Electric Co., Ltd.), 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate (Carenz MOI-BP [registered trademark], Showa Polymers produced using compounds having a block isocyanate group, such as (manufactured by Major Co., Ltd.) can be mentioned.

Specific examples of such a polymer include, for example, poly(2-isocyanatoethylacrylate), poly(2-(0-[1'-methylpropylideneamino]carboxyamino)ethylmethacrylate), 2 -A copolymer of isocyanatoethyl methacrylate and styrene, and a copolymer of 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate and methyl methacrylate. The weight average molecular weight of such a polymer is 1,000 to 200,000, more preferably 3,000 to 150,000, and still more preferably 3,000 to 50,000.

These crosslinking agents can be used alone or in combination of two or more.

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

[Preparation of liquid crystal aligning agent]

It is preferable that the liquid crystal aligning agent used for this invention is prepared as a coating liquid so that it may become suitable for formation of a liquid crystal aligning film. In other words, it is preferable that the liquid crystal aligning agent of the present invention is prepared as a solution in which a resin component for forming a resin film is dissolved in an organic solvent. Here, the resin component is a specific polymer that is the component (A) already described. In that case, the content of the specific polymer is preferably 0.5 to 20% by mass, more preferably 1 to 20% by mass, still more preferably 1 to 15% by mass, and particularly preferably 1 to 20% by mass with respect to the entire liquid crystal aligning agent. It is preferably 10% by mass.

<Solvent>

The solvent contained in the liquid crystal aligning agent used for this invention is not specifically limited if it is a solvent which dissolves the component (A) and the component (B) which has if necessary. 1 type may be sufficient as the solvent contained in a liquid crystal aligning agent, and may mix and use 2 or more types. Moreover, even if it is not a solvent which dissolves (A) component or (B) component, it can use together with a solvent which dissolves (A) component or (B) component. In this case, if the surface energy of the solvent that does not dissolve the component (A) or the component (B) is lower than the solvent dissolving the component (A) or the component (B), the coating property of the liquid crystal aligning agent to the substrate is satisfactory. It is desirable because it can be done.

As specific examples, N-alkyl-2-pyrrolidones such as water, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethyl Acetamide, N-methylcaprolactam, tetramethylurea, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropane Dialkylimidazolidinones such as amide and 1,3-dimethyl-2-imidazolidinone, lactones such as γ-butyrolactone, γ-valerolactone, and δ-valerolactone, ethylene carbonate, propylene Carbonates such as carbonate, methanol, ethanol, propanol, isopropanol, 3-methyl-3-methoxybutanol, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, isoamylmethyl ketone, methyl isopropyl ketone, diisobutyl ketone , Ketones such as cyclohexanone, cyclopentanone, methyl isobutyl ketone, and 4-hydroxy-4-methyl-2-pentanone, a compound represented by the following formula (Sv-1), and the following formula (Sv-2) The represented compound, 4-methyl-2-pentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, 2-methylcyclohexyl acetate, butyl butyrate, isoamyl butyrate, diisobutylcarbinol, di Isopentyl ether and the like.

[Formula 11]

In formulas (Sv-1) to (Sv-2), Y ₁ and Y ₂ are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, X ₁ is an oxygen atom or -COO-, and X ₂ Is a single bond or a carbonyl group, and R ₁ is an alkanediyl group having 2 to 4 carbon atoms. 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 C 1 to C 6 divalent hydrocarbon group, and Y ₃ and Y ₄ are each independently a hydrogen atom or a C 1 to C 6 monovalent hydrocarbon group).

In formula (Sv-1), as _{a C 1 to C 6 monovalent hydrocarbon group of Y 1} and Y ₂ , for example, a C 1 to C 6 monovalent chain hydrocarbon group or a C 1 to C 6 monovalent alicyclic hydrocarbon Group and a C1-C6 monovalent aromatic hydrocarbon group, etc. are mentioned. As a C1-C6 monovalent chain hydrocarbon group, a C1-C6 alkyl group etc. are mentioned. The _{alkanediyl group of R 1} may be linear or branched.

In formula (Sv-2), examples of the divalent hydrocarbon group having 1 to 6 carbon atoms of _{Z 1 include an alkanediyl group having 1 to 6 carbon atoms.}

As _{the C1-C6 monovalent hydrocarbon group of Y 3} and Y ₄ , a C1-C6 monovalent chain hydrocarbon group, a C1-C6 monovalent alicyclic hydrocarbon group, and a C1-C6 monovalent aromatic hydrocarbon And the like. As a C1-C6 monovalent chain hydrocarbon group, a C1-C6 alkyl group etc. are mentioned.

Specific examples of the solvent represented by formula (Sv-1) include, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, and ethylene glycol monobutyl. Ether (butyl cellosolve), ethylene glycol monohexyl ether, ethylene glycol dimethyl ether, ethylene glycol monoacetate, ethylene glycol diacetate, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene Glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol mono Butyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monomethyl ether, propylene glycol diacetate, ethylene glycol, 1,4-butanediol, 3-methoxybutyl acetate, 3-ethoxybutyl acetate, and the like;

As a specific example of the solvent represented by (Sv-2), for example, methyl glycolate, ethyl glycolate, butyl glycolate, ethyl lactate, butyl lactate, isoamyl lactate, ethyl-3-ethoxypropionate, Methyl-3-methoxypropionate, 3-methoxy ethylpropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropionate propyl, 3-methoxypropionate butyl, and the like, respectively.

It is preferable that the solvent has a boiling point of 80 to 200°C. More preferably, it is 80 degreeC to 180 degreeC, and as a preferable solvent, N,N-dimethylformamide, tetramethylurea, 3-methoxy-N,N-dimethylpropanamide, propanol, isopropanol, 3-methyl-3 -Methoxybutanol, ethyl amyl ketone, methyl ethyl ketone, isoamylmethyl ketone, methyl isopropyl ketone, diisobutyl ketone, 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, diisobutylcarbinol, diisopentyl ether, 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 dimethyl ether, ethylene glycol monoacetate, 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 -Methoxy propionate, 3-methoxy ethyl propionate, etc. are mentioned.

It is particularly preferable that the boiling point is in this range when the liquid crystal aligning agent containing the solvent is applied onto a plastic substrate described later.

<Other ingredients>

The liquid crystal aligning agent used for this invention may contain components other than the said (A) component and (B) component. Examples of such other components include a crosslinking catalyst, a compound that improves film thickness uniformity and surface smoothness when a liquid crystal aligning agent is applied, a compound that improves the adhesion between the liquid crystal aligning film and the substrate, and the like. It is not limited to

<crosslinking catalyst>

A crosslinking catalyst may be added to the liquid crystal aligning agent used in the present invention for the purpose of accelerating the reaction between the thermally crosslinkable group A and the thermally crosslinkable group B. As such a crosslinking catalyst, p-toluenesulfonic acid, camphorsulfonic acid, trifluoromethanesulfonic acid, p-phenolsulfonic acid, 2-naphthalenesulfonic acid, mesitylenesulfonic acid, p-xylene-2-sulfonic acid, m-xylene-2 -Sulfonic acid, 4-ethylbenzenesulfonic acid, 1H,1H,2H,2H-perfluorooctanesulfonic acid, perfluoro(2-ethoxyethane)sulfonic acid, pentafluoroethanesulfonic acid, nonafluorobutane-1-sulfonic acid, And sulfonic acids such as dodecylbenzenesulfonic acid, or hydrates and salts thereof. As a compound that generates an acid by heat, for example, bis(tosyloxy)ethane, bis(tosyloxy)propane, bis(tosyloxy)butane, p-nitrobenzyltosylate, o-nitrobenzyltosylate, 1 ,2,3-phenylene tris (methylsulfonate), p-toluenesulfonic acid pyridinium salt, p-toluenesulfonic acid morphonium salt, p-toluenesulfonic acid ethyl ester, p-toluenesulfonic acid propyl ester, p-toluenesulfonic acid butyl ester , p-toluene sulfonic acid isobutyl ester, p-toluene sulfonic acid methyl ester, p-toluene sulfonic acid phenethyl ester, cyanomethyl p-toluene sulfonate, 2,2,2-trifluoroethyl p-toluene sulfonate, 2 -Hydroxybutyl p-toluenesulfonate, N-ethyl-p-toluenesulfonamide, etc. are mentioned.

[Compound to improve the uniformity of film thickness or surface smoothness]

As a compound which improves the uniformity of film thickness and surface smoothness, a fluorine type surfactant, a silicone type surfactant, a nonion type surfactant, etc. are mentioned.

Specifically, for example, Ftop (registered trademark) 301, EF303, EF352 (manufactured by Tochem Products), Megapac (registered trademark) F171, F173, R-30 (manufactured by DIC), Fluorad FC430, FC431 (Manufactured by Sumitomo 3M), Asahigard (registered trademark) AG710 (manufactured by Asahi Glass Corporation), Suflon (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by AGC Seimi Chemical) And the like.

The ratio of these surfactants to be used is preferably 0.01 parts by mass to 2 parts by mass, more preferably 0.01 parts by mass to 1 part by mass per 100 parts by mass of the resin component contained in the polymer composition.

[Compound to improve adhesion between liquid crystal alignment film and substrate]

As a specific example of the compound which improves the adhesiveness of a liquid crystal aligning film and a board|substrate, the functional silane-containing compound etc. shown below are mentioned.

For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3 -Aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxy Carbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetri Amine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl Acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3- Aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylene)-3-aminopropyltrimethoxysilane, N-bis(oxyethylene)-3-aminopropyltri And amino-based silane-containing compounds such as ethoxysilane.

When a compound that improves adhesion to a substrate is used, the amount used is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass per 100 parts by mass of the resin component contained in the polymer composition. It's wealth.

In certain embodiments, a photosensitizer may be used as an additive in order to improve the photoreactivity of the photoalignable group. As a specific example, aromatic 2-hydroxyketone (benzophenone), coumarin, ketocoumarin, carbonylbiscoumarin, acetophenone, anthraquinone, xanthone, thioxanthone, and acetophenone ketal, etc. are mentioned.

In the liquid crystal aligning agent used in the present invention, all of the above-described resin components may be the specific polymers described above, but other polymers (hereinafter, also referred to as “other polymers”) may be mixed. In that case, as the content of the other polymer in the resin component, 5 to 95 parts by mass, or 10 to 90 parts by mass per 100 parts by mass of the total of the component (A) and the other polymer can be cited.

Examples of such other polymers include poly(meth)acrylates, polyamic acids, polyamic acid esters, polyimides, and the like, which do not satisfy at least one of the constitutional requirements of the specific polymer.

As the said other polymer, as a polyimide and its precursor (hereinafter, also referred to as a polyimide component), a polymer having a surface energy close to that of the polymer as the component (A) is preferable. Acrylic components such as component (A) basically have low polarity and low surface energy. On the other hand, the polyimide component has high polarity and high surface energy. However, if the difference between the surface energy of the two components is too large, there is a concern that the process margin is narrowed due to the formation of a film with irregularities due to the occurrence of coagulation due to poor compatibility, or the occurrence of cratering or non-uniformity. . Therefore, by lowering the polarity of the polyimide component, the surface energy is higher than that of the acrylic component, but the difference can be controlled to a small value. As a method of lowering 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 known tetracarboxylic acid derivative such as tetracarboxylic dianhydride and a known diamine, followed by chemical imidization, a polyimide precursor obtained using a diamine having a side chain, and A polyimide obtained by imidization, a polyimide precursor obtained using a diamine having a tertiarybutoxycarbonyloxy group, and a polyimide obtained by imidizing it may be mentioned. Since the surface energy can be brought close to the acrylic polymer as the component (A) by such side chain or chemical imidization, when a cured film is formed by applying and firing a liquid crystal aligning agent, no aggregation or the like occurs, and flat curing You can give it a film. As the diamine having a side chain, the diamine represented by formulas (2), (3), (4) and (5) described in paragraphs [0023] to [0039] of WO2016/125870, and specific examples thereof The diamine represented by formula [A-1]-[A-32] is mentioned. As the diamine having a tertiarybutoxycarbonyloxy group, the formulas [A-1], [A-2], and [A-3] described in paragraphs [0011] to [0034] of WO2017/119461 The diamine having a structure and the diamine exemplified as a specific example thereof can be mentioned.

<Liquid crystal alignment film and liquid crystal display element>

The liquid crystal aligning agent of the present invention can be applied onto a substrate and fired, and then subjected to alignment treatment by rubbing treatment, light irradiation, or the like, or can be used as a liquid crystal alignment film without alignment treatment in some vertical alignment applications. Examples of the substrate include glass such as float glass and soda glass; Polyethylene terephthalate, polybutylene terephthalate, polypropylene, polystyrene, polyethersulfone, polycarbonate, poly(alicyclic olefin), polyvinyl chloride, polyvinylidene chloride, polyetheretherketone (PEEK) resin film, polysulfone Transparent substrates made of plastics such as (PSF), polyethersulfone (PES), polyamide, polyimide, acrylic, and triacetylcellulose can be used.

As a transparent conductive film formed on one side of the substrate, a _{NESA film made of tin oxide (SnO 2} ) (registered trademark of PPG, USA), an ITO film made of _{indium oxide-tin oxide (In 2} O ₃ -SnO _{2 ), etc.} Can be used.

<Coating film formation process>

The method of applying the liquid crystal aligning agent of the present invention is not particularly limited, and there are screen printing, flexo printing, offset printing, inkjet, dip coating, roll coating, slit coating, spin coating, and the like, and may be used depending on the purpose. After coating on a substrate by these methods, the solvent can be evaporated by heating means such as a hot plate to form a coating film.

The firing after applying the liquid crystal aligning agent can be carried out at an arbitrary temperature of 40 to 300°C, preferably 40°C to 250°C, and more preferably 40°C to 230°C. When using a transparent substrate made of a plastic substrate, it is preferably 40 to 150°C, more preferably 80 to 140°C. The firing time is preferably 0.1 to 15 minutes, more preferably 1 to 10 minutes.

The film thickness of the coating film formed on the substrate is preferably 5 to 1,000 nm, more preferably 10 to 500 nm or 10 to 300 nm. This firing can be performed by a hot plate, a hot air circulation furnace, an infrared furnace, or the like.

<light irradiation process>

The light irradiation step in the present invention is a first irradiation step in which ultraviolet rays are irradiated from an oblique direction to the cured film obtained in the coating film formation step, and the cured film after irradiation with the ultraviolet rays is different from the first irradiation step. A mask including a second irradiation step of irradiating ultraviolet rays from different directions in this order, and at least one of the first irradiation step and the second irradiation step includes a shaded region and an unshielded region It is carried out through the intervening.

As the light to be irradiated in 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 exemplified. Among these, ultraviolet rays containing light having a wavelength of 300 to 400 nm are preferable. The irradiated light may be polarized or non-polarized. As polarized light, it is preferable to use light containing linearly polarized light.

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

The irradiation direction of ultraviolet rays is usually 1° to 89° with respect to the substrate normal, preferably 20° to 70°, and particularly preferably 30° to 60°. When this angle is too small, there is a problem that the pretilt angle becomes small, and when it is too large, there is a problem that design of the irradiation device becomes difficult.

As a method of adjusting the irradiation direction to the above angle, there are a method of tilting the substrate itself and a method of tilting the light source, but tilting the light source itself is more preferable from the viewpoint of throughput.

Further, according to the present invention, by using a specific composition, the pretilt angle formed by irradiation of ultraviolet rays in one direction can be canceled by irradiation of ultraviolet rays in another direction, and a different pretilt angle can be formed.

Accordingly, by forming a pretilt angle in a specific direction by, for example, exposure of the entire surface of ultraviolet rays, and then irradiating ultraviolet rays in different directions through a mask, a plurality of regions having different orientation directions are easily formed (orientation division) It becomes possible to do so, and it is possible to efficiently manufacture a multi-domain liquid crystal display element.

In the multi-domain liquid crystal alignment film obtained by the production method of the present invention, the pretilt angle is a pretilt angle suitable for the vertical alignment mode, from 90° to minus 0.1° to minus 10° inclined region 1 and 90° to plus 0.1° to plus It is preferred to have a 10° tilt zone 2. That is, it is preferable to have a region 1 of 80° to 89.9° and a region 2 of 90.1° to 100° as the pretilt angle, and more preferably have a region 1 of 85° to 89° and a region 2 of 91° to 95°. desirable.

In addition, when forming the regions 1 and 2, the region 1 may be formed in the first irradiation step, the region 2 may be formed in the second irradiation step, or the region 2 is formed in the first irradiation step, The region 1 may be formed in the second irradiation step. When the first irradiation step is performed without a mask, it is preferable that the irradiation amount of light in the second irradiation step is larger than the irradiation amount of light in the first irradiation step. On the other hand, when the first irradiation step is carried out through a mask, 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 a pattern-shaped mask is used together in the first irradiation step and the second irradiation step, even if the mask is shifted, the tilt of the first irradiation region is canceled in the second irradiation region, and the second irradiation step Since it can be rewritten at a tilt angle by irradiation of the mask, it does not become a "dark line" when the mask is shifted.

The liquid crystal display device of the present invention can be manufactured by a conventional method using the multi-domain liquid crystal alignment film obtained in the present invention, and the manufacturing method is not particularly limited. It is preferable to arrange a spacer between the substrates for the purpose of making the pair of substrates face each other via an appropriate gap, and to make the thickness of the liquid crystal sandwiched between the substrates uniform. As this spacer, a known spacer material such as a conventional scattered spacer and a spacer formed from a photosensitive spacer-forming composition can be used, and as a spacer, irregularities formed on a layer made of a liquid crystal cured product can be used as spacers. It is possible.

<liquid crystal holding process>

In order to configure a liquid crystal cell by sandwiching a liquid crystal between substrates, for example, the following two methods are mentioned. As a first method, a pair of substrates are opposed to each other through a gap (cell gap) so that each liquid crystal aligning film faces, and the periphery of the pair of substrates is bonded using a sealing agent, and the substrate surface And a method of manufacturing a liquid crystal cell by filling and injecting liquid crystal into the cell gap partitioned by an appropriate sealing agent, and then sealing the injection hole.

As a second method, for example, an ultraviolet light-curable sealing material was applied to a predetermined place on one of the two substrates on which the liquid crystal alignment film was formed, and liquid crystal was dripped at several predetermined locations on the surface of the liquid crystal alignment film. Thereafter, a method of manufacturing a liquid crystal cell by bonding the other substrate so that the liquid crystal aligning film is opposed to each other, expanding the liquid crystal to the entire surface of the substrate, and then curing the sealing agent by irradiating ultraviolet light to the entire surface of the substrate (ODF ( One Drop Fill) method).

As a liquid crystal, a fluorine-based liquid crystal or cyano-based liquid crystal having positive or negative dielectric anisotropy depending on the application, and a liquid crystal compound or liquid crystal composition that is polymerized by at least one treatment during heating and light irradiation (hereinafter , Also referred to as a polymerizable liquid crystal or curable liquid crystal composition) may be used.

In any embodiment, the step of forming the coating film of the liquid crystal aligning agent may be performed by a roll-to-roll method. When implemented by the roll-to-roll system, the manufacturing process of the liquid crystal display element is simplified, and therefore, it becomes possible to reduce the manufacturing cost.

And a liquid crystal display element can be obtained by attaching a polarizing plate to the outer both surfaces of the said liquid crystal cell.

Examples of the polarizing plate used on the outside of the liquid crystal cell include a polarizing plate in which a polarizing film called ``H film'' absorbed iodine while stretching and aligning polyvinyl alcohol is sandwiched by a cellulose acetate protective film, or a polarizing plate made of the H film itself. I can.

The liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention as described above has good liquid crystal alignment, excellent pretilt angle expression ability, and high reliability. Further, 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 examples is shown below.

In addition, in the formula, "t" represents that a cyclohexyl group is trans-type.

[Formula 12]

MA-1, MA-2, MA-3, and MA-4 are photoalignable monomers, and CR-1, CR-2, MOI-BP, HEMA, and MAA are thermal crosslinkable monomers.

[Formula 13]

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

[Formula 14]

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

The symbol of the organic solvent used in Examples etc. is as follows.

PGME: Propylene glycol monomethyl ether

CHN: Cyclohexanone

The abbreviation of the polymerization initiator used in Examples etc. is as follows.

AIBN: 2, 2'-azobisisobutyronitrile

<Measurement of polymer molecular weight>

The molecular weight of the polymer in the synthesis example was measured as follows using a normal temperature gel permeation chromatography (GPC) apparatus (SSC-7200) manufactured by Senshu Scientific Co., Ltd. and a column manufactured by Shodex (KD-803, KD-805).

Column temperature: 50 °C

Eluent: DMF (as an additive, lithium bromide monohydrate (LiBr H ₂ O) is 30 mmol/L, phosphoric acid anhydrous crystal (o-phosphoric acid) is 30 mmol/L, THF is 10 mL/L)

Flow rate: 1.0 ml/min

Standard samples for calibration curve preparation: TSK standard polyethylene oxide (molecular weight: about 9000,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation, and polyethylene glycol (molecular weight: about 12,000, 4,000, 1,000) manufactured by Polymer Laboratories.

<Reference Example 1>

After dissolving MA-1 (4.95 g, 12.0 mmol) and MOI-BP (7.04 g, 28.0 mmol) in CHN (69.8 g), degassing with a diaphragm pump, AIBN (0.33 g, 2.0 mmol) ) Was added and degassed again. After this, it reacted at 55 degreeC for 13 hours, and obtained the polymer solution of methacrylate. This polymer solution was dripped in a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the obtained deposit was filtered. Methanol wash|cleaned this deposit, it dried under reduced pressure in 40 degreeC oven, and obtained the methacrylate polymer powder (A). The number average molecular weight of this polymer was 44200, and the weight average molecular weight was 141800.

CHN (18.0 g) was added to the obtained methacrylate polymer powder (A) (1.5 g), and stirred at room temperature for 5 hours to dissolve. A liquid crystal aligning agent (A1) was obtained by adding and stirring CR-1 (0.15 g) and PGME (18.0 g) to this solution.

<Example 1-0>

[Manufacture of liquid crystal cell]

The liquid crystal aligning agent (A1) obtained in Reference Example 1 was spin-coated on the ITO surface of a glass substrate with a transparent electrode made of an ITO film, and dried for 300 seconds on a 40°C hot plate. Subsequently, it baked for 10 minutes with a 120 degreeC hot plate, and the liquid crystal aligning film with a film thickness of 100 nm was formed. After that, the liquid crystal alignment film was attached by irradiating linearly polarized ultraviolet light of 313 nm with an irradiation intensity of 4.3 mW/cm 2 from an angle of 40° inclined to the substrate normal direction through a polarizing plate on the coating surface of the alignment film. The substrate was obtained. The 313 nm linearly polarized ultraviolet light to be irradiated was taken out by passing ultraviolet light emitted from a high-pressure mercury lamp through a 313 nm band pass filter and a Brewster polarizing plate.

Two of the above substrates were prepared, and a 4 µm bead spacer was dispersed on the liquid crystal alignment film of one substrate, and then a sealing agent (manufactured by Mitsui Chemicals, XN-1500T) was applied. Subsequently, the other substrate was bonded so that the liquid crystal alignment layer faced the surface and the irradiation direction of the incident polarized ultraviolet light was 180° with respect to the irradiation direction of the ultraviolet light incident on the opposite substrate, and then at 120°C. An empty cell was prepared by thermally curing the 90 minute sealing agent. A negative liquid crystal (MLC-3022, manufactured by Merck) was injected into this empty cell by a reduced pressure injection method to prepare a liquid crystal cell.

[Evaluation of pre-tilt angle]

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

[Evaluation of liquid crystal orientation]

After liquid crystal cell production, isotropic treatment at 120° C. for 1 hour, then cell observation was performed with a polarizing microscope, and uniform liquid crystal was driven when there was no misalignment such as light leakage or domain occurrence, or when voltage was applied to the liquid crystal cell. The case where this was obtained was regarded as good orientation. The results are summarized in Table 1.

<Example 1-1>

In the [Production of Liquid Crystal Cell] of Example 1-0, after irradiation of 50 mJ/cm 2 of linearly polarized ultraviolet rays from an angle inclined by 40° in the direction of the substrate normal, and 50 mJ from an angle inclined by 40° in the direction of the substrate normal. A liquid crystal cell was obtained by the same method as in Example 1-0 except that /cm 2 irradiation was performed. In addition, the first irradiation and the second irradiation were respectively inclined by 40° in the opposite direction from the normal direction. Moreover, the pretilt angle and liquid crystal cell orientation were evaluated by the method similar to Example 1-0.

<Examples 1-2 and 1-3>

In the [production of a liquid crystal cell] of Example 1-1, except for changing the second polarized ultraviolet irradiation dose to 100 mJ/cm 2 (Example 1-2) and 150 mJ/cm 2 (Example 1-3) , A liquid crystal cell was obtained by the same method as in Example 1-1. Moreover, the pretilt angle and liquid crystal cell orientation were evaluated by the method similar to Example 1-0.

<Reference Example 2>

MA-1 (4.95 g, 12.0 mmol), MOI-BP (3.52 g, 14.0 mmol), and HEMA (1.82 g, 14.0 mmol) were dissolved in CHN (60.2 g) and degassed with a diaphragm pump. Then, AIBN (0.33 g, 2.0 mmol) was added, and deaeration was performed again. After this, it reacted at 55 degreeC for 13 hours, and obtained the polymer solution of methacrylate. This polymer solution was dripped in a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the obtained deposit was filtered. Methanol wash|cleaned this deposit, and it dried under reduced pressure in 40 degreeC oven, and obtained the methacrylate polymer powder (B). The number average molecular weight of this polymer was 33800, and the weight average molecular weight was 123500.

CHN (18.0 g) was added to the obtained methacrylate polymer powder (B) (1.5 g), and stirred at room temperature for 5 hours to dissolve. A liquid crystal aligning agent (B1) was obtained by adding and stirring PGME (18.0 g) to this solution.

<Reference Example 3>

After dissolving MA-1 (3.30 g, 8.0 mmol) and MAA (2.75 g, 32.0 mmol) in CHN (36.2 g) and degassing with a diaphragm pump, AIBN (0.33 g, 2.0 mmol) was prepared. It was added and degassed again. After this, it reacted at 55 degreeC for 13 hours, and obtained the polymer solution of methacrylate. This polymer solution was dripped in a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the obtained deposit was filtered. Methanol wash|cleaned this deposit, and it dried under reduced pressure in 40 degreeC oven, and obtained the methacrylate polymer powder (C). The number average molecular weight of this polymer was 51500, and the weight average molecular weight was 143000.

CHN (18.0 g) was added to the obtained methacrylate polymer powder (C) (1.5 g), followed by stirring at room temperature for 5 hours to dissolve. A liquid crystal aligning agent (C1) was obtained by adding and stirring CR-2 (0.45 g) and PGME (18.0 g) to this solution.

<Reference Example 4>

X-4 (2.28 g, 3.00 mmol), X-5 (1.22 g, 4.00 mmol), X-6 (1.45 g, 3.00 mmol) and X-1 (2.23 g, 6.00 mmol) were converted into NMP ( 27.2 g), and after reacting at 60°C for 5 hours, X-2 (1.00 g, 2.00 mmol) and X-3 (0.87 g, 2.00 mmol) and NMP (9.1 g) were added, and 40 It reacted at degreeC for 10 hours, and obtained the polyamic acid polymer solution.

After NMP was added to the polyamic acid polymer solution (50 g) and diluted to 6.5% by mass, acetic anhydride (8.8 g) and pyridine (2.7 g) were added as an imidation catalyst, followed by reaction at 75°C for 2.5 hours. This reaction solution was poured into methanol (700 ml), and the obtained precipitate was separated by filtration. Methanol wash|cleaned this deposit, it dried under reduced pressure at 100 degreeC, and obtained the polyimide polymer powder. The imidation ratio of this polyimide polymer was 71 %, the number average molecular weight was 13000 and the weight average molecular weight was 42000.

NMP (44.0 g) was added to the obtained polyimide powder (6.0 g), and it was stirred and dissolved at 70 degreeC for 20 hours. A polyimide polymer solution (H1) was obtained by adding NMP (10.0 g) and BCS (40.0 g) to this solution and stirring at room temperature for 5 hours.

A liquid crystal aligning agent (D1) was obtained by stirring the obtained polyimide polymer solution (H1) (14.0 g) and the liquid crystal aligning agent (B1) (6.0 g) obtained in Reference Example 2 at room temperature for 5 hours.

<Reference Example 5>

A liquid crystal aligning agent (E1) was obtained by stirring the polyimide polymer solution (H1) (14.0 g) obtained in Reference Example (4) and the liquid crystal aligning agent (C1) (6.0 g) obtained in Reference Example 3 at room temperature for 5 hours .

<Examples 2-0 to 5-3>

In place of the liquid crystal aligning agent (A1) obtained in Reference Example 1, except having used the liquid crystal aligning agent described in Table 1, a test was performed in the same manner as in Examples 1-0 to 1-3. Table 1 shows the evaluation results.

<Reference Example 6>

After dissolving MA-2 (13.74 g, 24.0 mmol) and MA-3 (7.02 g, 16.0 mmol) in CHN (119.5 g), degassing with a diaphragm pump, AIBN (0.33 g, 2.0 mmol) ) Was added and degassed again. After this, it reacted at 55 degreeC for 13 hours, and obtained the polymer solution of methacrylate. This polymer solution was dripped in a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the obtained deposit was filtered. Methanol wash|cleaned this deposit, and it dried under reduced pressure in 40 degreeC oven, and obtained the methacrylate polymer powder (D). The number average molecular weight of this polymer was 35700, and the weight average molecular weight was 126000.

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. A liquid crystal aligning agent (F1) was obtained by adding and stirring CHN (18.0 g) to this solution.

<Comparative Example 1-0>

[Manufacture of liquid crystal cell]

The liquid crystal aligning 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, dried for 300 seconds on a hot plate at 40°C, and had a film thickness of 100 nm. A liquid crystal alignment film was formed. A 313 nm linearly polarized ultraviolet ray with an irradiation intensity of 4.3 mW/cm 2 was irradiated on the surface of the coating film by 50 mJ/cm 2 from an angle inclined at 40° in the direction of the substrate normal. Then, it baked for 10 minutes with a 120 degreeC hot plate, and the board|substrate with a liquid crystal aligning film was obtained. The vertically polarized UV was prepared by passing a 313 nm band pass filter through the ultraviolet light of a high-pressure mercury lamp, and then passing a 313 nm polarizing plate.

Two of the above substrates were prepared, a 4 µm bead spacer was scattered on the liquid crystal alignment film of one of the substrates, and then a sealing agent (manufactured by Kyoritsu Chemical Co., Ltd., XN-1500T) was applied. Subsequently, the other substrate was bonded so that the liquid crystal alignment layer faced and the alignment direction was 180°, and then the sealing agent was thermally cured at 120° C. for 90 minutes to prepare an empty cell. A negative liquid crystal (MLC-3022, manufactured by Merck) was injected into this empty cell by a reduced pressure injection method to prepare a liquid crystal cell.

Moreover, the pretilt angle and liquid crystal cell orientation were evaluated by the method similar to Example 1-0.

<Comparative Example 1-1>

In [Production of Liquid Crystal Cell] of Comparative Example 1-0, after irradiation of 50 mJ/cm 2 of linearly polarized ultraviolet rays from an angle inclined at 40° in the direction of the substrate normal, and 50 mJ from an angle inclined at 40° in the normal direction of the substrate A liquid crystal cell was obtained by the same method as in Comparative Example 1-0 except that /cm 2 irradiation was performed. In addition, the first irradiation and the second irradiation were respectively inclined by 40° in the opposite direction from the normal direction. Moreover, the pretilt angle and liquid crystal cell orientation were evaluated by the method similar to Example 1-0.

<Comparative Examples 1-2, 1-3>

In the [production of a liquid crystal cell] of Comparative Example 1-0, except that the second polarized ultraviolet irradiation amount was changed to 100 mJ/cm 2 (Comparative Example 1-2) and 150 mJ/cm 2 (Comparative Example 1-3). , A liquid crystal cell was obtained by the same method as in Comparative Example 1. Moreover, the pretilt angle and liquid crystal cell orientation were evaluated by the method similar to Example 1-0.

<Reference Example 7>

MA-2 (17.18 g, 30.0 mmol) and MAA (1.72 g, 20.0 mmol) were dissolved in NMP (108.51 g), degassed with a diaphragm pump, and then AIBN (0.25 g, 1.5 mmol) was prepared. It was added and degassed again. After this, it reacted at 55 degreeC for 13 hours, and obtained the polymer solution of methacrylate. This polymer solution was dripped in a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the obtained deposit was filtered. Methanol wash|cleaned this deposit, it dried under reduced pressure in 40 degreeC oven, and the methacrylate polymer powder (E) was obtained. The number average molecular weight of this polymer was 22700, and the weight average molecular weight was 131000.

CHN (18.0 g) was added to the obtained methacrylate polymer powder (E) (1.5 g), and stirred at room temperature for 5 hours to dissolve. A liquid crystal aligning agent (G1) was obtained by adding and stirring CHN (18.0 g) to this solution.

<Comparative Examples 2-0 to 2-3>

Using the liquid crystal aligning agent (G1) obtained in Reference Example 7, except having changed the firing temperature from 120 degreeC to 150 degreeC, it tested similarly to Comparative Examples 1-0 to 1-3.

<Reference Example 8>

After dissolving MA-4 (4.05 g, 8.0 mmol) and MAA (2.75 g, 32.0 mmol) in CHN (28.5 g) and degassing with a diaphragm pump, AIBN (0.33 g, 2.0 mmol) was prepared. It was added and degassed again. After this, it reacted at 55 degreeC for 13 hours, and obtained the polymer solution of methacrylate. This polymer solution was dripped in a mixed solvent (1000 ml) of methanol and pure water = 5/5, and the obtained deposit was filtered. Methanol wash|cleaned this deposit, it dried under reduced pressure in a 40 degreeC oven, and the methacrylate polymer powder (H) was obtained. The number average molecular weight of this polymer was 47,000, and the weight average molecular weight was 140000.

CHN (18.0 g) was added to the obtained methacrylate polymer powder (H) (1.5 g), followed by stirring at room temperature for 5 hours to dissolve. A liquid crystal aligning agent (I1) was obtained by adding CR-2 (0.45 g) and PGME (18.0 g) to this solution, and stirring.

<Reference Example 9>

Liquid crystal aligning agent (J1) by stirring the polyimide polymer solution (H1) (14.0 g) obtained in Reference Example (4) and the liquid crystal aligning agent (I1) (6.0 g) obtained in Reference Example (8) for 5 hours at room temperature Got it.

<Examples 6-0 to 7-3>

In place of the liquid crystal aligning agent (A1) obtained in Reference Example 1, except having used the liquid crystal aligning agent described in Table 2, the test was performed in the same manner as in Examples 1-0 to 1-3. Table 2 shows the evaluation results.

As is clear from Tables 1 and 2, in Examples, by performing the second irradiation, rewriting of the tilt angle was possible, and the liquid crystal orientation after rewriting was also good. On the other hand, in the comparative examples, rewriting of the tilt angle was impossible in all cases.

Industrial applicability

According to the manufacturing method of this invention, a multi-domain liquid crystal aligning film can be manufactured efficiently. Moreover, the liquid crystal display element using the obtained multi-domain liquid crystal aligning film can be used suitably for the liquid crystal display element for ECB, etc.

Claims (5)

As a method for producing a multi-domain liquid crystal alignment film, the method,
A process of applying a liquid crystal aligning agent on a 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,
The cured film after ultraviolet irradiation obtained by the first irradiation step includes, in this order, a second irradiation step of irradiating ultraviolet rays in a direction different from the irradiation direction in the first irradiation step,
At least one of the first irradiation step and the second irradiation step is performed via a mask including a shaded region and an unshielded region,
The said liquid crystal aligning agent is (A) following formula (pa-1)

(In the formula, A is depending on a group selected from fluorine, chlorine, and cyano as the case may be, or an alkoxy group having 1 to 5 carbon atoms, a linear or branched alkyl moiety (this is, in some cases, one cyano Pyrimidine-2,5-diyl, pyridin-2,5-diyl, 2,5-thiophenylene, 2,5-furanylene, 1, which may be substituted with a no group or one or more halogen atoms) Represents 4- or 2,6-naphthylene or phenylene, R ₁ is a single bond, an oxygen atom, -COO- or -OCO-, and R ₂ is a divalent aromatic group, a divalent alicyclic group, and a divalent heterocycle A type group or a divalent condensed cyclic group, R ₃ is a single bond, an oxygen atom, -COO- or -OCO-, and R ₄ is a C 1 to C 40 linear or branched alkyl group or an alicyclic group containing 3 carbon atoms It is a monovalent organic group of -40, D represents an oxygen atom, a sulfur atom, or -NR _d- (here, R _d represents a hydrogen atom or an alkyl having 1 to 3 carbon atoms), and a represents 0 to 3 It is an integer, and * represents a bonding position.)
A polymer having a photoalignable group represented by and a thermal crosslinkable group A, and
Contains a solvent, and also
The liquid crystal aligning agent,
Z ₁ : The (A) polymer further has a thermal crosslinkable group B, and/or
Z ₂ : (B) further containing a compound having two or more thermal crosslinkable groups B in the molecule
(Thermal crosslinkable group A and the thermal crosslinkable group B are each independently a carboxyl group, an amino group, an alkoxymethylamide group, a hydroxymethylamide group, a hydroxyl group, an epoxy moiety-containing group, an oxetanyl group, a thiranyl group, an isocyanate group, and a block. As a group selected from the group consisting of an isocyanate group, the thermally crosslinkable group A and the thermally crosslinkable group B are selected to undergo a crosslinking reaction by heat, provided that the thermally crosslinkable group A and the thermally crosslinkable group B may be the same as each other.)
Characterized in that, the method. The method of claim 1,
The method, 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 of claim 1,
The method, wherein only the second irradiation step is performed through the mask. A multi-domain liquid crystal alignment film formed using the method according to any one of claims 1 to 3. A liquid crystal display device comprising the multi-domain liquid crystal alignment film according to claim 4.

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