Radical-generating film-forming composition, radical-generating film, method for producing liquid crystal display element, and liquid crystal display element

Abstract

Provided is a composition for forming a radical-generating film, which contains: a component (A), a polymer used as an alignment component of a liquid crystal aligning agent for in-plane switching; and a component (B), a polymer which contains a group represented by formula (1) and which has a structural unit derived from a monomer having a polymerizable carbon-carbon unsaturated bond. (In formula (1), * denotes a bonding position, and R1 denotes a single bond, -CH2-, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH2O-, -N(CH3)-, -CON(CH3)-, or -N(CH3)CO-.　R2 denotes a single bond or a C1-20 alkylene group which is unsubstituted or substituted with a fluorine atom. One or more arbitrary -CH2- or -CF2- moieties in the alkylene group may each independently be substituted with a group selected from among -CH=CH-, an optionally substituted divalent carbon ring and an optionally substituted divalent heterocyclic ring. Furthermore, one or more arbitrary -CH2- or -CF2- moieties in the alkylene group may be substituted with the groups listed below, that is, may be substituted with at least one of -O-, -COO-, -OCO-, -NHCO-, -CONH- or -NH- as long as these are not adjacent to each other.　R3 denotes an organic group that induces radical polymerization.)

Description

[Technical Field]

[0001] The present invention relates to a method for producing a liquid crystal display element that can produce a weak anchoring film using an inexpensive method that does not involve any complicated steps, and that applies a technology for stabilizing a liquid crystal layer using a polymer, a liquid crystal display element that can be driven at an even lower voltage, and a radical-generating film-forming composition and a radical-generating film that can be used for the same. [Background technology]

[0002] In recent years, liquid crystal display elements have been widely used in displays for mobile phones, computers, and televisions. Liquid crystal display elements have characteristics such as thinness, light weight, and low power consumption, and are expected to be applied to a wider range of content in the future, such as virtual reality (VR) and ultra-high-definition displays. Various display modes have been proposed for liquid crystal displays, including twisted nematic (TN), in-plane switching (IPS), and vertical alignment (VA). All modes use a film (liquid crystal alignment film) that guides the liquid crystals into the desired alignment state.

[0003] IPS mode is particularly popular for products equipped with touch panels, such as tablet PCs, smartphones, and smart TVs, as it is less likely to distort the display when touched. In recent years, LCD display elements using FFS (Friction Field Switching) and non-contact technology using optical alignment have become popular in order to improve contrast and viewing angle characteristics.

[0004] However, FFS requires higher substrate manufacturing costs than IPS, and suffers from the problem of display defects specific to FFS mode, known as Vcom shift. Furthermore, photo-alignment has the advantage of being able to produce larger elements and significantly improving display characteristics compared to the rubbing method, but it also has inherent problems with the photo-alignment principle (display defects resulting from decomposition products in the case of decomposition-type displays, and image retention due to insufficient alignment force in the case of isomerization-type displays). Currently, LCD display element manufacturers and LCD alignment film manufacturers are working on various ideas to solve these problems.

[0005] On the other hand, in recent years, an IPS mode that utilizes something called weak anchoring has been proposed, and it has been reported that using this technique can improve contrast and enable significantly lower voltage operation compared to conventional IPS modes (see Patent Document 1).

[0006] Specifically, one of the substrates is made of a liquid crystal alignment film with strong anchoring energy, while the other substrate, equipped with the electrode that generates the horizontal electric field, is treated so that it has no liquid crystal alignment control power whatsoever, and these are used to create an IPS mode liquid crystal display element.

[0007] In recent years, a weak anchoring IPS mode technology has been proposed, which uses dense polymer brushes to create a weak state (see Patent Document 2). This technology has achieved a significant improvement in contrast ratio and a significant reduction in drive voltage.

[0008] However, there is a problem of a significant drop in response speed, especially when the voltage is turned off. This is due to the effect of the lower drive voltage causing the display to respond with a weaker electric field than with conventional drive methods, and also because the anchoring strength of the alignment film is extremely weak, which means it takes a long time for the liquid crystal to return to its original state.

[0009] To solve this problem, a method has been proposed in which weak anchoring is applied only to the pixel electrode (see Patent Document 3). It has been reported that this method makes it possible to achieve both improved brightness and faster response. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Patent No. 4053530 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-231757 [Patent Document 3] Japanese Patent Application Publication No. 2017-211566 Summary of the Invention [Problem to be solved by the invention]

[0011] While weak anchoring only on the electrodes of an IPS comb electrode reduces response speed delays during operation, achieving weak anchoring only on the electrodes requires difficult technology such as painting different materials on very small areas, which is likely to pose a major challenge to actual industrialization. Furthermore, the design of materials to achieve a weak anchoring state is significantly different from the design of conventional liquid crystal alignment films using polyimides, and there are many unknown aspects to the design guidelines. When characteristics such as coating film formability and electrical properties are taken into account, the development is extremely difficult, and it is likely to take a very long time to find a material that can be put to practical use. In fact, there are very few reports of materials that can achieve a weak anchoring state simply by coating, and the current situation is far from being at a practical level.

[0012] If these technical challenges can be resolved, it will bring significant cost benefits to panel manufacturers, and it is thought that this will also result in benefits such as reduced battery consumption and improved image quality.

[0013] The present invention has been made to solve the above-mentioned problems, and aims to provide a method for producing a liquid crystal display element that can be easily produced, can simultaneously achieve a low driving voltage and a fast response speed when the voltage is off, and can also produce an in-plane switching liquid crystal display element that is capable of producing a good black display and that is well suppressed from sticking, as well as the liquid crystal display element, and a radical-generating film-forming composition and radical-generating film that can be used for the liquid crystal display element and the liquid crystal display element. [Means for solving the problem]

[0014] The present inventors have conducted extensive research to solve the above problems, and as a result have found that the above problems can be solved, and have completed the present invention having the following gist.

[0015] That is, the present invention includes the following. [1] Component (A): a polymer used as an alignment component of a liquid crystal alignment agent for in-plane switching drive, and Component (B): a polymer containing a group represented by the following formula (1) and having a structural unit derived from a monomer having a polymerizable carbon-carbon unsaturated bond, A radical-generating film-forming composition comprising: [ka] (In formula (1), * represents a binding site, and R 1 represents a single bond, -CH2-, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CHO-, -N(CH3)-, -CON(CH3)-, or -N(CH3)CO-. R 2represents a single bond, or an alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted with a fluorine atom, and one or more -CH2- or -CF2- in the alkylene group are each independently optionally replaced with a group selected from -CH=CH-, an optionally substituted divalent carbocycle, and an optionally substituted divalent heterocycle, and further, one or more -CH2- or -CF2- in the alkylene group are optionally replaced with at least one of the following groups, i.e., -O-, -COO-, -OCO-, -NHCO-, -CONH-, or -NH-, provided that these groups are not adjacent to each other. R 3 represents an organic group that induces radical polymerization. [2] R 3 represents an organic group that induces radical polymerization and is represented by the following formula [W], [Y], or [Z]: [ka] (In formulas [W], [Y], and [Z], * represents a bonding site, Ar represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene, and biphenylylene, which may have an organic group and / or a halogen atom as a substituent, and R 9 and R 10 each independently represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, and R 9 and R 10 When each of the groups is an alkyl group, they may be bonded to each other at the terminals to form a ring structure. Q represents one of the following structures: [ka] (In the formula, R 11 represents -CH2-, -NR-, -O-, or -S-, and each R independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and * indicates a bonding site.) S 3 represents a single bond, -O-, -NR- (wherein R represents a hydrogen atom or an alkyl group having 1 to 14 carbon atoms), or -S-. R 12represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. [3] The radical-generating film-forming composition according to [1] or [2], wherein the polymer as component (A) is a polyimide precursor or a polyimide. [4] The radical-generating film-forming composition according to any one of [1] to [3], wherein the polymer as component (A) does not contain an organic group that induces radical polymerization. [5] The radical-generating film-forming composition according to any one of [1] to [4], wherein the content of the component (B) is 0.1 to 20 mass % relative to the content of the component (A). [6] A radical-generating film obtained by using the radical-generating film-forming composition according to any one of [1] to [5]. [7] A step of preparing a first substrate having the radical-generating film according to [6] and a second substrate which may have a radical-generating film; disposing the first substrate and the second substrate so that the radical generating film on the first substrate faces the second substrate; Filling a liquid crystal composition containing liquid crystal and a radical polymerizable compound between the first substrate and the second substrate; and a step of polymerizing the radical polymerizable compound while the liquid crystal composition is in contact with the radical-generating film; A method for manufacturing a liquid crystal display element comprising the steps of: [8] The method for producing a liquid crystal display element according to [7], wherein the second substrate is a second substrate that does not have a radical-generating film. [9] The method for producing a liquid crystal display element according to [7], wherein the second substrate is a substrate coated with a liquid crystal alignment film having uniaxial alignment properties.

[10] The method for manufacturing a liquid crystal display element according to [9], wherein the liquid crystal alignment film having uniaxial alignment is a liquid crystal alignment film for horizontal alignment.

[11] The method for manufacturing a liquid crystal display element according to any one of [7] to

[10] , wherein either the first substrate or the second substrate is a substrate having a comb-shaped electrode.

[12] A liquid crystal display device comprising: a first substrate; a second substrate disposed opposite to the first substrate; and a liquid crystal filled between the first substrate and the second substrate; A liquid crystal display element characterized in that a liquid crystal composition containing the liquid crystal and a radical polymerizable compound is brought into contact with the radical generating film of the first substrate having the radical generating film described in [6], and the radical polymerizable compound is polymerized in the state. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a method for producing a liquid crystal display element that can be easily produced, can simultaneously achieve a low driving voltage and a fast response speed when the voltage is off, and can produce an in-plane switching liquid crystal display element that is capable of good black display and good suppression of image sticking, as well as the liquid crystal display element, a radical-generating film-forming composition that can be used for the liquid crystal display element, and a radical-generating film. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic cross-sectional view showing an example of a horizontal electric field liquid crystal display element of the present invention. [Figure 2] FIG. 10 is a schematic cross-sectional view showing another example of the in-plane switching liquid crystal display element of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] [Radical-generating film-forming composition] The radical-generating film-forming composition of the present invention contains at least the following component (A) and component (B): Component (A): A polymer used as an alignment component of a liquid crystal alignment agent for in-plane switching drive Component (B): A polymer containing a group represented by the following formula (1) and having a structural unit derived from a monomer having a polymerizable carbon-carbon unsaturated bond: [ka] (In formula (1), * represents a binding site, and R 1represents a single bond, -CH2-, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CHO-, -N(CH3)-, -CON(CH3)-, or -N(CH3)CO-. R 2 represents a single bond, or an alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted with a fluorine atom, and one or more -CH2- or -CF2- in the alkylene group may each independently be replaced with a group selected from -CH=CH-, a divalent carbocycle which may have a substituent, and a divalent heterocycle which may have a substituent, and further, one or more -CH2- or -CF2- in the alkylene group may be replaced with at least one of the following groups, i.e., -O-, -COO-, -OCO-, -NHCO-, -CONH-, or -NH-, provided that these groups are not adjacent to each other. R 3 represents an organic group that induces radical polymerization.

[0019] By applying and curing such a composition to form a film, a radical-generating film can be obtained in which organic groups that induce radical polymerization are fixed in the film. The method for producing a liquid crystal display element of the present invention, which will be described later, includes a step of polymerizing a radical-polymerizable compound while contacting a liquid crystal composition containing liquid crystal and a radical-polymerizable compound with a radical-generating film obtained using the radical-generating film-forming composition of the present invention. The inventors speculate that in this step, a change occurs on the surface of the radical-generating film due to the polymerization reaction of the radical-polymerizable compound using radicals generated by the radical-generating film, resulting in a weak anchoring film. However, it is difficult to confirm whether the change on the surface of the radical-generating film resulting from this step is due to a change in the radical-generating film itself or due to the formation of a polymerized layer of the radical-polymerizable compound on the radical-generating film. Therefore, the result of this step has not yet been identified.

[0020] In the present invention, by carrying out the above steps, it is possible to stably produce a weak anchoring lateral electric field liquid crystal display element, simultaneously achieving a low driving voltage and a fast response speed when the voltage is off, and in addition, it is possible to produce a lateral electric field liquid crystal display element with good suppression of burn-in.

[0021] In this invention, a "weak anchoring film" refers to a film that has no in-plane alignment control force for liquid crystal molecules, or if any, the force is weaker than the intermolecular forces between liquid crystal molecules, and thus does not uniaxially align liquid crystal molecules in any direction by itself. Furthermore, this weak anchoring film is not limited to solid films but also includes liquid films covering solid surfaces. Liquid crystal display elements typically use a pair of films that control the alignment of liquid crystal molecules, i.e., liquid crystal alignment films, to align liquid crystals. However, the use of a pair of weak anchoring films and liquid crystal alignment films can also align liquid crystals. This is because the alignment control force of the liquid crystal alignment film is transmitted in the thickness direction of the liquid crystal layer through the intermolecular forces between liquid crystal molecules, resulting in the alignment of liquid crystal molecules adjacent to the weak anchoring film. Therefore, when a liquid crystal alignment film for horizontal alignment is used as the liquid crystal alignment film, horizontal alignment can be achieved throughout the liquid crystal cell. Horizontal alignment refers to a state in which the long axes of liquid crystal molecules are aligned approximately parallel to the plane of the liquid crystal alignment film; tilted alignment of a few degrees is also included in the category of horizontal alignment.

[0022] <Ingredient (B)> Component (B) is a polymer containing a group represented by the following formula (1). Component (B) is a polymer having structural units derived from a monomer having a polymerizable carbon-carbon unsaturated bond. In other words, component (B) is a polymer obtained by utilizing polymerization of the polymerizable carbon-carbon unsaturated bond of a monomer having a polymerizable carbon-carbon unsaturated bond. [ka] (In formula (1), * represents a binding site, and R 1 represents a single bond, -CH2-, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CHO-, -N(CH3)-, -CON(CH3)-, or -N(CH3)CO-. R 2 represents a single bond, or an alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted with a fluorine atom, and one or more -CH2- or -CF2- in the alkylene group may each independently be replaced with a group selected from -CH=CH-, a divalent carbocycle which may have a substituent, and a divalent heterocycle which may have a substituent, and further, one or more -CH2- or -CF2- in the alkylene group may be replaced with at least one of the following groups, i.e., -O-, -COO-, -OCO-, -NHCO-, -CONH-, or -NH-, provided that these groups are not adjacent to each other. R 3 represents an organic group that induces radical polymerization.

[0023] Examples of the substituent in the optionally substituted divalent carbocyclic ring and the optionally substituted divalent heterocyclic ring include a halogen atom, an alkyl group, an alkoxy group, an amino group, a hydroxy group, and a carboxy group. Examples of halogen atoms include fluorine atoms, chlorine atoms, and bromine atoms. The alkyl group may, for example, be an alkyl group having 1 to 6 carbon atoms. Examples of the alkoxy group include alkoxy groups having 1 to 6 carbon atoms. The number of substituents in the divalent carbocyclic ring and the divalent heterocyclic ring is not particularly limited.

[0024] R 2 Examples of the group include a divalent group represented by the following formula (1-1). [ka] (In formula (1-1), *1 is R 1 *3 represents the binding site with R 3 represents the binding site with R 4 represents a divalent carbocyclic ring which may have a substituent or a divalent heterocyclic ring which may have a substituent, m represents 0 or 1, and n represents an integer of 1 to 6. -C in formula (1-1) n H 2n The - (n represents an integer of 1 to 6) may be a linear alkylene group or a branched alkylene group.

[0025] R 4 Examples of the group include a divalent group represented by the following formula (1-2). [ka] (In formula (1-2), *1 is R 1 represents a bonding site with -O-, * represents a bonding site with -O-, and k represents an integer of 0 to 4. P represents a substituent. When k is 2 or more, the Ps may be the same or different. The binding site*1 and the binding site* may be at the 1,2 positions, the 1,3 positions, or the 1,4 positions. The substituent represented by P includes, for example, an amino group.

[0026] R 3 is not particularly limited as long as it is an organic group that induces radical polymerization, and examples thereof include organic groups that induce radical polymerization represented by the following formula [W], [Y], or [Z]. [ka] (In formulas [W], [Y], and [Z], * represents a bonding site, Ar represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene, and biphenylylene, which may have an organic group and / or a halogen atom as a substituent, and R 9 and R 10 each independently represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, and R 9 and R 10 When each of the groups is an alkyl group, they may be bonded to each other at the terminals to form a ring structure. Q represents one of the following structures: [ka] (In the formula, R 11represents -CH2-, -NR-, -O-, or -S-, and each R independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and * indicates a bonding site.) S 3 represents a single bond, -O-, -NR- (wherein R represents a hydrogen atom or an alkyl group having 1 to 14 carbon atoms), or -S-. R 12 represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.

[0027] Examples of the group represented by formula (1) include the following groups. [ka] (In the formula, * indicates a binding site.)

[0028] The method for producing the polymer as component (B) is not particularly limited, but examples thereof include the following production methods (i) and (ii), or a combination thereof. (i): A monomer having a group represented by formula (1) and a polymerizable carbon-carbon unsaturated bond is polymerized, and if necessary, other monomers having a polymerizable carbon-carbon unsaturated bond are used in combination to obtain a polymer as component (B). (ii): Polymerization is performed using a monomer having a polymerizable carbon-carbon unsaturated bond but not having a group represented by formula (1) to obtain polymer (B'), and then the polymer (B') is reacted with a compound having a group represented by formula (1) to obtain a polymer as component (B).

[0029] The monomer having a group represented by formula (1) and a polymerizable carbon-carbon unsaturated bond is not particularly limited as long as it has a group represented by formula (1) and a polymerizable carbon-carbon unsaturated bond, and examples thereof include monomers represented by the following formula (2): [ka] (In formula (2), R 1 , R 2 , and R 3 are R in formula (1), respectively. 1 , R2 , and R 3 is the same as R a represents a radical polymerizable group represented by any one of the following formulas [X-1] to [X-18]. R a The formula [X-1] or [X-2] is preferred. [ka] (In formulas [X-1] to [X-18], * represents a bonding site, S1 and S2 each independently represent -O-, -NR-, or -S-, and R represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (some of the -CH2- groups in the alkyl group having 2 to 10 carbon atoms among the alkyl group having 1 to 10 carbon atoms may be replaced with oxygen atoms. However, when some of the -CH2- groups in the alkyl group in S2R or NR are replaced with oxygen atoms, the oxygen atoms are not directly bonded to S2 or N). R1 ​​and R2 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.)

[0030] Other examples of the monomer having a polymerizable carbon-carbon unsaturated bond include monomers having a radical polymerizable group represented by any of the above formulae [X-1] to [X-18]. Other monomers having a polymerizable carbon-carbon unsaturated bond include, for example, methacrylate monomers such as methyl methacrylate, ethyl methacrylate, tert-butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, lauryl methacrylate, and n-octyl methacrylate; acrylate monomers such as methyl acrylate, ethyl acrylate, tert-butyl acrylate, benzyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, lauryl acrylate, and n-octyl acrylate; styrene and styrene derivatives (e.g., o-, m-, and p-methoxystyrene, o-, m-, and p-tert-butoxystyrene, Examples of the vinyl monomer include, but are not limited to, vinyl monomers such as o-, m-, and p-chloromethylstyrene, vinyl esters (e.g., vinyl acetate, vinyl propionate, and vinyl benzoate), vinyl ketones (e.g., vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone), N-vinyl compounds (e.g., N-vinylpyrrolidone, N-vinylpyrrole, N-vinylcarbazole, and N-vinylindole), (meth)acrylic acid derivatives (e.g., acrylonitrile, methacrylonitrile, acrylamide, isopropylacrylamide, and methacrylamide), and vinyl halides (e.g., vinyl chloride, vinylidene chloride, tetrachloroethylene, hexachloroprene, and vinyl fluoride).

[0031] The number of polymerizable carbon-carbon unsaturated bonds in the monomer having a polymerizable carbon-carbon unsaturated bond used as component (B) in the method for producing the polymer is not particularly limited, and may be one, two, or more. However, from the viewpoint of solvent solubility, the number of polymerizable carbon-carbon unsaturated bonds in the monomer is preferably one. That is, the number of polymerizable carbon-carbon unsaturated bonds in the monomer having a group represented by formula (1) and a polymerizable carbon-carbon unsaturated bond is preferably one. The number of polymerizable carbon-carbon unsaturated bonds in the other monomers having a polymerizable carbon-carbon unsaturated bond is preferably one. The number of polymerizable carbon-carbon unsaturated bonds in a monomer having a polymerizable carbon-carbon unsaturated bond but not having a group represented by formula (1) is preferably one.

[0032] In the above (ii), examples of the method for obtaining polymer (B') by polymerization using a monomer having a polymerizable carbon-carbon unsaturated bond and not having a group represented by formula (1) include a method for polymerizing maleic acid alone or together with other monomers. The other monomers include, for example, isobutylene. In the above (ii), the polymer (B') may be a commercially available product, such as ISOBAM-10 (manufactured by Kuraray Co., Ltd.). In the above (ii), a polymer (B') is reacted with a compound having a group represented by formula (1) to obtain a polymer as component (B). Examples of the compound having a group represented by formula (1) include compounds represented by the following formula (3). [ka] (In formula (3), R 1 , R 2 , and R 3 are R in formula (1), respectively. 1 , R 2 , and R 3 Rs represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. The reaction between the polymer (B') and the compound represented by formula (3) can be carried out by utilizing a known bond-forming reaction, such as an ester bond-forming reaction, an amide bond-forming reaction, a urethane bond-forming reaction, a urea bond-forming reaction, a carbon-carbon bond-forming reaction, etc. The reaction temperature and reaction time in the reaction are not particularly limited.

[0033] The polymer (B) is, for example, a polymer (P) having at least one structural unit selected from the group consisting of the following formulae (m-1) and (m-2): Such a polymer (P) can be obtained, for example, by the production method (ii) above. [ka] (R 1 and R 2 each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 3 carbon atoms. R represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Rs represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. X represents a group represented by formula (1).

[0034] In formulas (m-1) and (m-2), R 1 and R 2 are preferably each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R 1 is a hydrogen atom and R 2 is more preferably a hydrogen atom or an alkyl group having 1 carbon atom, and R 1 and R 2 It is more preferred that is a hydrogen atom. R is preferably a hydrogen atom. Rs is preferably a hydrogen atom.

[0035] The polymer (P) may contain one or more of the structural units represented by formulae (m-1) and (m-2). The total content of the structural units represented by formulae (m-1) and (m-2) is preferably 5 to 80 mol %, more preferably 10 to 50 mol %, based on the total structural units of the polymer (P).

[0036] A polymer having a structural unit represented by formula (m-1) can be obtained, for example, by reacting a polymer having a structural unit containing a maleic anhydride skeleton (maleic anhydride polymer) with one or more primary or secondary amino compounds. In this reaction, the amino group of the primary or secondary amino compound is added to the carbonyl group of the maleic anhydride skeleton, and a ring-opening reaction proceeds to obtain the structural unit represented by formula (m-1).

[0037] The polymer having a structural unit containing a maleic anhydride skeleton is preferably a maleic anhydride polymer containing a structural unit represented by the following formula (m) (hereinafter also referred to as structural unit (m)), and more preferably a maleic anhydride copolymer (hereinafter also referred to as copolymer (Mp)) containing the structural unit (m) and a structural unit represented by the following formula (v) (hereinafter also referred to as structural unit (v)). [ka] (R 1 and R 2 R each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 3 carbon atoms. 3 , R 4 , R 5 and R 6 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, -OC(=O)-R (R represents an alkyl group having 1 to 6 carbon atoms), -C(=O)-OR (R represents an alkyl group having 1 to 6 carbon atoms), -OR (R represents an alkyl group having 1 to 6 carbon atoms), or a phenyl group.

[0038] Examples of the structural unit (v) include ethylene, propylene, n-butene, isobutylene, n-pentene, n-hexene, acrylates and methacrylates having an alkyl group having 1 to 4 carbon atoms (hereinafter also referred to as "alkyl acrylates having 1 to 4 carbon atoms" and "alkyl methacrylates having 1 to 4 carbon atoms"). [ka] (R is hydrogen or an alkyl group having 1 to 6 carbon atoms, and the benzene ring may be optionally substituted with an alkyl group having 1 to 4 carbon atoms or a hydroxyl group.)

[0039] Preferred examples of alkyl acrylates having 1 to 4 carbon atoms include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-propyl acrylate, n-butyl acrylate, and mixtures thereof. Preferred examples of alkyl methacrylates having 1 to 4 carbon atoms include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-propylmethyl methacrylate, n-butyl methacrylate, and mixtures thereof. A mixture of alkyl methacrylates having 1 to 4 carbon atoms and alkyl acrylates having 1 to 4 carbon atoms may be used. Preferred examples of styrenic compounds include styrene, α-methylstyrene, p-methylstyrene, tert-butylstyrene, and mixtures thereof. A mixture of a styrenic compound and alkyl acrylates and / or methacrylates having 1 to 4 carbon atoms may be used. Among these, isobutylene or a mixture of isobutylene, 1-butene, and 2-butene is particularly preferred.

[0040] The structural unit (m) preferably accounts for 10 to 50 mol %, more preferably 30 to 50 mol %, of all structural units constituting the copolymer (Mp). The molecular weight of the copolymer (Mp) is preferably a weight average molecular weight of 3,000 to 500,000, more preferably 8,000 to 150,000.

[0041] An example of the primary or secondary amino compound is a compound represented by formula (3). [ka] (In formula (3), R 1 , R 2 , and R 3 are R in formula (1), respectively.1 , R 2 , and R 3 Rs represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0042] The reaction between a polymer having a structural unit containing a maleic anhydride skeleton and a primary or secondary amino compound is preferably carried out in an organic solvent. Examples of the organic solvent that can be used include alcohols, ethers, ketones, amides, esters, and hydrocarbon compounds. In the above reaction, the reaction temperature is preferably 30 to 120°C, and the reaction time is preferably 1 to 24 hours. The reaction solution in which the polymer is dissolved may be used as it is, or the polymer contained in the reaction solution may be isolated using a known isolation method, such as a method of pouring the reaction solution into a large amount of poor solvent and drying the resulting precipitate under reduced pressure, or a method of distilling the reaction solution under reduced pressure using an evaporator, and then the polymer may be used for preparing a polymer composition.

[0043] The reaction amount of the primary or secondary amino compound is preferably 0.01 to 1.2 equivalents, more preferably 0.1 to 1.2 equivalents, and even more preferably 0.1 to 1.0 equivalents, relative to the anhydride group in the structural unit (m).

[0044] A polymer having a structural unit represented by formula (m-1) in which R is an alkyl group having 1 to 10 carbon atoms can be obtained, for example, by esterifying a polymer having a structural unit represented by formula (m-1) in which R is hydrogen. The esterification can be carried out in the same manner as in obtaining a polyamic acid ester from a polyamic acid.

[0045] A polymer having a structural unit represented by formula (m-2) can be obtained by ring-closing a polymer having a structural unit represented by formula (m-1). The polymer (P) may contain a structural unit represented by formula (m-1) in addition to the structural unit represented by formula (m-2). Methods for obtaining a polymer having a structural unit represented by formula (m-2) include thermal imidization, in which a solution of a polymer having a structural unit represented by formula (m-1) is heated as is, and catalytic imidization, in which a catalyst is added. When thermal imidization is performed in a solution, the temperature is, for example, 100 to 400°C, preferably 120 to 250°C, and it is preferable to perform the imidization while removing water generated by the imidization reaction from the system.

[0046] Catalytic imidization can be carried out by adding a basic catalyst, and if necessary, an acid anhydride, to a polymer solution having a structural unit represented by formula (m-2), and stirring the mixture at a temperature usually between -20 and 250°C, preferably between 0 and 180°C. The amount of the basic catalyst is, for example, 0.5 to 30 times by mole, preferably 2 to 20 times by mole, the amount of the amic acid groups, and the amount of the acid anhydride is, for example, 1 to 50 times by mole, preferably 3 to 30 times by mole, the amount of the amic acid groups. Examples of basic catalysts include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, and N,N-dimethyl-4-aminopyridine.

[0047] The polymer (P) may further have structural units other than those represented by formulae (m), (m-1), (m-2), and (v). Examples of structural units other than those represented by formulae (m), (m-1), (m-2), and (v) include structural units represented by the following formulae (m-3) to (m-4) or structural units derived from other compounds having an ethylenic double bond. [ka] (R 1 , R 2 , R, and Rs are defined as in the formulae (m-1) to (m-2). Y represents a hydrogen atom or a monovalent organic group other than X in the formulae (m-1) to (m-2).

[0048] Specific examples of the monovalent organic group for Y in formulas (m-3) and (m-4) include carboxyl group-containing monoamines such as p-aminobenzoic acid; alicyclic group-containing monoamines such as cyclohexylamine; alkyl group-containing monoamines such as n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, and n-eicosylamine; or monovalent organic groups derived from aniline.

[0049] Examples of the other compounds having an ethylenic double bond include carboxyl group-containing compounds such as acrylic acid, methacrylic acid, α-ethylacrylic acid, 2-hydroxyethyl(meth)acrylic acid, 4-vinylbenzoic acid, and maleic acid; hydroxyl group-containing compounds such as 2-hydroxyethyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, 4-hydroxybutyl(meth)acrylate, and N-methylol(meth)acrylamide; isooctyl acrylate, isodecyl acrylate, and lauryl acrylate. compounds containing a long-chain alkyl group such as acrylate, decyl methacrylate, and stearyl acrylate; compounds containing an alicyclic group such as cyclohexyl (meth)acrylate; compounds containing a benzene ring such as 2-phenoxyethyl acrylate and ethoxylated nonylphenyl acrylate; compounds containing an oxiranyl group such as glycidyl (meth)acrylate, methyl glycidyl (meth)acrylate, and 4-(glycidyloxy)butyl (meth)acrylate; compounds having an isocyanate group or a protected isocyanate group such as 2-methacryloyloxyethyl isocyanate (Karenz MOI, manufactured by Showa Denko K.K.) and 2-[(3,5-dimethylpyrazoyl)carbonylamino]ethyl methacrylate (Karenz MOI-BP, manufactured by Showa Denko K.K.); and compounds having a tetrahydrofurfuryl group such as tetrahydrofurfuryl methacrylate.

[0050] The polymer (P) may contain one type of structural unit represented by formula (v) alone or two or more types thereof. The content of the structural unit represented by formula (v) is preferably 50 to 90 mol %, more preferably 30 to 70 mol %, based on the total structural units of the polymer (P).

[0051] When obtaining the polymer (B) in the above production method (i), and when obtaining the polymer (B') in the above production method (ii), polymerization is carried out, for example, in the presence of a radical polymerization initiator. The radical polymerization initiator may be a radical thermal polymerization initiator used in a general radical thermal polymerization reaction. The radical thermal polymerization initiator is a compound that generates radicals when heated to a temperature equal to or higher than its 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.), hydroperoxides (hydrogen peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyketals (dibutylperoxycyclohexane, etc.), alkyl peresters (peroxyneodecanoic acid-tert-butyl ester, peroxypivalic acid-tert-butyl ester, peroxy-2-ethylcyclohexanoic acid-tert-amyl ester, etc.), persulfates (potassium persulfate, sodium persulfate, ammonium persulfate, etc.), and azo compounds (azobisisobutyronitrile, 2,2′-di(2-hydroxyethyl)azobisisobutyronitrile, etc.). Such radical thermal polymerization initiators can be used alone or in combination of two or more.

[0052] The polymer as component (B) is produced, for example, by the above method (i), (ii) or a combination thereof in the presence of an organic solvent. The organic solvent to be used is not particularly limited as long as the produced polymer is soluble in it. Furthermore, even if the polymer is not soluble in the organic solvent, it may be mixed with the above-mentioned solvent to the extent that the produced polymer does not precipitate.

[0053] Examples of the organic solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylformamide, N-methylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, N-methyl-ε-caprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethylphosphoramide, γ-butyrolactone, isopropyl alcohol, methoxymethylpentane, methylpropanediol ... ethanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate , propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol tert-butyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 1,Examples of suitable organic solvents include 4-dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, and 2-ethyl-1-hexanol. These organic solvents may be used alone or in combination.

[0054] In the above (i), the reaction temperature and reaction time of the polymerization reaction to obtain the polymer as component (B) are not particularly limited. The reaction temperature is, for example, 50 to 100°C. The reaction time is, for example, 1 to 48 hours. In the above (ii), the reaction temperature and reaction time of the polymerization reaction to obtain the polymer (B') are not particularly limited. The reaction temperature is, for example, 50 to 100°C. The reaction time is, for example, 1 to 48 hours.

[0055] The molecular weight of the polymer as component (B) is not particularly limited, but considering the strength of the radical-generating film obtained by applying the radical-generating film-forming composition, the workability during film formation, the uniformity of the film, and the like, the weight-average molecular weight measured by GPC (Gel Permeation Chromatography) is preferably 1,000 to 1,000,000, and more preferably 10,000 to 150,000.

[0056] The content of the polymer as component (B) in the radical-generating film-forming composition is not particularly limited, but from the viewpoints of liquid crystal alignment, film flatness, seal adhesion, etc., the content of component (B) is preferably 0.01 to 50 mass%, more preferably 0.05 to 40 mass%, even more preferably 0.1 to 20 mass%, and particularly preferably 0.5 to 5 mass%, relative to component (A).

[0057] <Component (A)> The polymer [component (A)] used as the alignment component of the in-plane switching drive liquid crystal alignment agent is not particularly limited, but is preferably at least one polymer selected from the group consisting of polyimide precursors, polyimides, polyureas, polyamides, polyacrylates, polymethacrylates, cellulose derivatives, polyacetals, polystyrene or its derivatives, poly(styrene-phenylmaleimide) derivatives, and polyorganosiloxanes. The component (A) is a polymer different from the component (B).

[0058] A preferred embodiment of component (A) is a polymer selected from polyamic acids obtained from a tetracarboxylic dianhydride component and a diamine component, and imidized products thereof.

[0059] An example of a tetracarboxylic dianhydride component for obtaining a polyamic acid, which is a preferred embodiment of component (A), is a compound represented by the following formula (A1).

[0060] [ka] In formula (A1), A is a tetravalent organic group, preferably a tetravalent organic group having 4 to 30 carbon atoms.

[0061] Preferred structures of A are shown below, but the present invention is not limited to these. [ka]

[0062] [ka]

[0063] Of the above structures, (A-1) and (A-2) are preferred from the viewpoint of further improving the photoalignment property, (A-4) is preferred from the viewpoint of improving the relaxation rate of the accumulated charge, and (A-15) to (A-17) are preferred from the viewpoint of further improving the liquid crystal alignment property and improving the relaxation rate of the accumulated charge. The tetracarboxylic dianhydride component for obtaining the polyamic acid of component (A) may be one type of tetracarboxylic dianhydride, or two or more types of tetracarboxylic dianhydrides may be used in combination.

[0064] <Diamine> The diamine component used in the polymerization of the polyamic acid of component (A) used in the radical-generating film-forming composition of the present invention preferably contains at least one diamine selected from the diamine represented by the following formula (A2) and the diamine represented by the following formula (A3):

[0065] [ka] A1 is a single bond, an alkylene group having 2 to 10 carbon atoms, or a group in which at least one -CH2- in the alkylene group has been replaced with -O- or -S- provided that they are not consecutive; A2 is independently a halogen atom, a hydroxy group, an amino group, a thiol group, a nitro group, a phosphate group, or a monovalent organic group having 1 to 20 carbon atoms; a is independently an integer of 0 to 4; and when there are multiple A2s, the structures of A2 may be the same or different; b and c are independently 1 or 2; and d is 0 or 1.

[0066] [ka]

[0067] Preferred specific examples of the diamine represented by formula (A2) are listed below, but the present invention is not limited to these. Among these, formulas (A2-1), (A2-3), (A2-5) to (A2-7), and (A2-12) are particularly preferred.

[0068] [ka]

[0069] Preferred specific examples of the diamine represented by formula (A3) are listed below, but the present invention is not limited to these.

[0070] [ka]

[0071] Furthermore, from the viewpoint of improving the solvent solubility of the polyimide and from the viewpoint of component (A) being more likely to be unevenly distributed near the surface layer of the liquid crystal alignment film when other polymers than component (A) and component (B) are contained in the radical-generating film-forming composition of the present invention, it is preferable to use at least one diamine represented by the following formula (A4) as the other diamine.

[0072] [ka] In formula (A4), Y1 is a divalent organic group containing the structure of formula (A5) below.

[0073] [ka] In formula (A5), D represents a protecting group that is eliminated by heating and replaced with a hydrogen atom, and * represents a connection site with another structure. A preferred structure for D is a tert-butoxycarbonyl group. Preferred specific examples of the diamine represented by formula (A4) are listed below, but the present invention is not limited to these. In the following structures, Boc represents a tert-butoxycarbonyl group.

[0074] [ka]

[0075] From the viewpoint of improving the relaxation rate of accumulated charges, it is preferable to use at least one diamine represented by the following formula (A6).

[0076] [ka] In formula (A6), Y2 is a divalent organic group having a nitrogen atom bonded to an aromatic group or having a nitrogen-containing aromatic heterocycle. Preferred structures of Y2 are shown below, but the present invention is not limited to these.

[0077] [ka]

[0078] The diamine used in the polymerization of component (A) contained in the radical-generating film-forming composition of the present invention may contain diamines other than those represented by the above formulas (A2) to (A6) (hereinafter also referred to as "other diamines"), as long as the effects of the present invention are not impaired. Examples of other diamines are listed below, but the present invention is not limited to these.

[0079] m-Phenylenediamine, 4-(2-(methylamino)ethyl)aniline, 3,5-diaminobenzoic acid, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 1,4-diaminonaphthalene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)propane, 1,3-bis(4-aminophenethyl)urea, etc.

[0080] The diamine component for obtaining the polyamic acid, which is component (A), may be one type of diamine, or two or more types of diamines may be used in combination.

[0081] The polymer selected from polyamic acids and imidized products thereof, which is component (A), may be a single polymer or a mixture of polymers obtained using the above-mentioned tetracarboxylic dianhydride component and the above-mentioned diamine component. When the polymers are a mixture, the individual polymers are different from each other.

[0082] The polymer as component (A) may or may not contain an organic group that induces radical polymerization. It is preferable to incorporate an organic group that induces radical polymerization when forming a polymerized layer, i.e., when reducing the UV irradiation dose or when improving film hardness, but from the viewpoints of liquid crystal alignment, response speed, storage stability, etc., it is considered preferable to incorporate a small amount of, or not have, an organic group that induces radical polymerization, and it is important to combine them appropriately.

[0083] When a polymer containing an organic group that induces radical polymerization is used as component (A), the organic group that induces radical polymerization can be, for example, an organic group that induces radical polymerization in the polymer as component (B).

[0084] When a polymer containing an organic group that induces radical polymerization is used as component (A), in order to obtain a polymer having a group that can generate radicals, it is preferable to produce the polymer using, as a monomer component, a monomer having a photoreactive side chain that contains at least one group selected from a methacrylic group, an acrylic group, a vinyl group, an allyl group, a coumaryl group, a styryl group, and a cinnamoyl group, or a monomer having a moiety in the side chain that decomposes upon irradiation with ultraviolet light to generate radicals. The monomer containing an organic group that induces radical polymerization is specifically a diamine having a side chain that can generate radicals and polymerize, and examples thereof include, but are not limited to, diamines having an organic group represented by the following formula (1): [ka] (In formula (1), * represents a binding site, and R 1 represents a single bond, -CH2-, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CHO-, -N(CH3)-, -CON(CH3)-, or -N(CH3)CO-. R 2 represents a single bond, or an alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted with a fluorine atom, and one or more -CH2- or -CF2- in the alkylene group may each independently be replaced with a group selected from -CH=CH-, a divalent carbocycle which may have a substituent, and a divalent heterocycle which may have a substituent, and further, one or more -CH2- or -CF2- in the alkylene group may be replaced with at least one of the following groups, i.e., -O-, -COO-, -OCO-, -NHCO-, -CONH-, or -NH-, provided that these groups are not adjacent to each other. R 3 represents an organic group that induces radical polymerization. Specific structures include the diamines shown below.

[0085] [ka] (In the formula, J 1 is a linking group selected from a single bond, —O—, —COO—, —NHCO—, and —NH—; J 2 represents a single bond, or an unsubstituted or fluorine atom-substituted alkylene group having 1 to 20 carbon atoms.

[0086] [ka] [ka] (wherein n is an integer of 2 to 8, and E is a single bond, -O-, -C(CH3)2-, -NH-, -CO-, -NHCO-, -CONH-, -COO-, -OCO-, or -(CH2) m -, -SO2-, -O-(CH2) m -O-, -OC(CH3)2-, -C(CH3)2-O-, -CO-(CH2) m -, -(CH2) m -CO-, -NH-(CH2) m -, -(CH2) m -NH-, -SO2-(CH2) m -, -(CH2) m -SO2-, -CONH-(CH2) m -, -(CH2) m -NHCO-, -CONH-(CH2) m -NHCO- or -COO-(CH2) m -OCO-, and m is an integer of 1 to 8.

[0087] In the synthesis when the polymer as component (A) is a polyamic acid ester, the structure of the tetracarboxylic acid dialkyl ester to be reacted with the diamine component is not particularly limited, but specific examples are given below.

[0088] Specific examples of aliphatic tetracarboxylic acid diesters include 1,2,3,4-cyclobutanetetracarboxylic acid dialkyl esters, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl esters, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl esters, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl esters, 1,2,3,4-cyclopentanetetracarboxylic acid dialkyl esters, tetrahydrofuran-2,3,4,5-tetracarboxylic acid dialkyl esters, 1,2,4,5-cyclohexanetetracarboxylic acid dialkyl esters, 2-(3,4-dicarboxycyclohexyl)succinic acid dialkyl esters, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid dialkyl esters, 1,2,3,4-butanetetracarboxylic acid dialkyl esters, alkyl esters, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic acid dialkyl esters, 3,3',4,4'-dicyclohexyltetracarboxylic acid dialkyl esters, 2,3,5-tricarboxycyclopentylacetic acid dialkyl esters, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic acid dialkyl esters, tricyclo[4.2.1.0<2,5>]nonane-3,4 ,7,8-tetracarboxylic acid-3,4:7,8-dialkyl ester, hexacyclo[6.6.0.1<2,7>.0<3,6>.1<9,14>.0<10,13>]hexadecane-4,5,11,12-tetracarboxylic acid-4,5:11,12-dialkyl ester, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid dialkyl ester, etc.

[0089] Examples of aromatic tetracarboxylic acid dialkyl esters include pyromellitic acid dialkyl esters, 3,3',4,4'-biphenyltetracarboxylic acid dialkyl esters, 2,2',3,3'-biphenyltetracarboxylic acid dialkyl esters, 2,3,3',4'-biphenyltetracarboxylic acid dialkyl esters, 3,3',4,4'-benzophenonetetracarboxylic acid dialkyl esters, 2,3,3',4'-benzophenonetetracarboxylic acid dialkyl esters, bis(3,4-dicarboxyphenyl)ether dialkyl esters, bis(3,4-dicarboxyphenyl)sulfone dialkyl esters, 1,2,5,6-naphthalenetetracarboxylic acid dialkyl esters, and 2,3,6,7-naphthalenetetracarboxylic acid dialkyl esters.

[0090] In the synthesis of polyurea as the polymer of component (A), the diisocyanate to be reacted with the diamine component is not particularly limited, and can be selected depending on availability, etc. Specific structures of diisocyanates are shown below. [ka] In the formula, R2 and R3 represent an aliphatic hydrocarbon group having 1 to 10 carbon atoms.

[0091] Aliphatic diisocyanates K-1 to K-5 have the advantage of being less reactive but improving solvent solubility, while aromatic diisocyanates K-6 to K-13 are highly reactive and have the effect of improving heat resistance, but have the disadvantage of reducing solvent solubility. In terms of versatility and properties, K-1, K-7, K-8, K-9, and K-10 are preferred, while K-12 is preferred from the viewpoint of electrical properties, and K-13 is preferred from the viewpoint of liquid crystal alignment. Two or more diisocyanates can be used in combination, and it is preferable to use various types depending on the desired properties.

[0092] Furthermore, a portion of the diisocyanate may be replaced with the tetracarboxylic dianhydride described above, and the diisocyanate may be used in the form of a copolymer of polyamic acid and polyurea, or may be used in the form of a copolymer of polyimide and polyurea obtained by chemical imidization.

[0093] In the synthesis of a polyamide polymer as component (A), the structure of the dicarboxylic acid to be reacted is not particularly limited, but specific examples are as follows: Aliphatic dicarboxylic acids include malonic acid, oxalic acid, dimethylmalonic acid, succinic acid, fumaric acid, glutaric acid, adipic acid, muconic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, 3,3-diethylsuccinic acid, azelaic acid, sebacic acid, and suberic acid.

[0094] Alicyclic dicarboxylic acids include 1,1-cyclopropanedicarboxylic acid, 1,2-cyclopropanedicarboxylic acid, 1,1-cyclobutanedicarboxylic acid, 1,2-cyclobutanedicarboxylic acid, 1,3-cyclobutanedicarboxylic acid, 3,4-diphenyl-1,2-cyclobutanedicarboxylic acid, 2,4-diphenyl-1,3-cyclobutanedicarboxylic acid, 1-cyclobutene-1,2-dicarboxylic acid, 1-cyclobutene-3,4-dicarboxylic acid, 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,1-cyclohexane ...3-cyclopentanedicarboxylic acid, 1,1-cyclohexanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,1-cyclohexanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,1-cyclohexanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, Examples of suitable carboxylic acids include 2,5-dioxo-1,4-bicyclo[2.2.2]octanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2-norbornene-1,4-dicarboxylic acid, 2-norbornene-2,3-dicarboxylic acid, bicyclo[2.2.2]octane-1,4-dicarboxylic acid, bicyclo[2.2.2]octane-2,3-dicarboxylic acid, 2,5-dioxo-1,4-bicyclo[2.2.2]octanedicarboxylic acid, 1,3-adamantanedicarboxylic acid, 4,8-dioxo-1,3-adamantanedicarboxylic acid, 2,6-spiro[3.3]heptanedicarboxylic acid, 1,3-adamantanediacetic acid, and camphoric acid.

[0095] Examples of aromatic dicarboxylic acids include o-phthalic acid, isophthalic acid, terephthalic acid, 5-methylisophthalic acid, 5-tert-butylisophthalic acid, 5-aminoisophthalic acid, 5-hydroxyisophthalic acid, 2,5-dimethylterephthalic acid, tetramethylterephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-anthracenedicarboxylic acid, anthraquinone-1,4-dicarboxylic acid, 2,5-biphenyldicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 1,5-biphenylenedicarboxylic acid, p-terphenyl-4,4"-dicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, 1,2-bis(4-carboxyphenyl)ethane, 2,2-bis(4-carboxyphenyl)propane, 2,2-bis(4 -Carboxyphenyl)hexafluoropropane, diphenyl ether-4,4'-dicarboxylic acid, bibenzyl-4,4'-dicarboxylic acid, 4,4'-stilbenedicarboxylic acid, tolan-4,4'-dicarboxylic acid, 4,4'-carbonyldibenzoic acid, 4,4'-sulfonyldibenzoic acid, 4,4'-dithiodibenzoic acid, p-phenylenediacetic acid, 3,3'-p-phenylenedipropionic acid, 4-carboxycinnamic acid Examples of suitable dicarboxylic acids include acrylic acid, p-phenylenediacrylic acid, 3,3'-[4,4'-(methylenedi-p-phenylene)]dipropionic acid, 4,4'-[4,4'-(oxydi-p-phenylene)]dipropionic acid, 4,4'-[4,4'-(oxydi-p-phenylene)]dibutyric acid, (isopropylidenedi-p-phenylenedioxy)dibutyric acid, and bis(p-carboxyphenyl)dimethylsilane.

[0096] Examples of dicarboxylic acids containing a heterocycle include 1,5-(9-oxofluorene)dicarboxylic acid, 3,4-furandicarboxylic acid, 4,5-thiazoledicarboxylic acid, 2-phenyl-4,5-thiazoledicarboxylic acid, 1,2,5-thiadiazole-3,4-dicarboxylic acid, 1,2,5-oxadiazole-3,4-dicarboxylic acid, 2,3-pyridinedicarboxylic acid, 2,4-pyridinedicarboxylic acid, 2,5-pyridinedicarboxylic acid, 2,6-pyridinedicarboxylic acid, 3,4-pyridinedicarboxylic acid, and 3,5-pyridinedicarboxylic acid.

[0097] The various dicarboxylic acids mentioned above may have an acid dihalide or anhydride structure. These dicarboxylic acids are preferably capable of producing polyamides with a linear structure, in order to maintain the alignment of liquid crystal molecules. Among these, terephthalic acid, isoterephthalic acid, 1,4-cyclohexanedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, 1,2-bis(4-carboxyphenyl)ethane, 2,2-bis(4-carboxyphenyl)propane, 2,2-bis(4-carboxyphenyl)hexafluoropropane, p-terphenyl-4,4"-dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,5-pyridinedicarboxylic acid, or acid dihalides thereof are preferably used. Some of these compounds have isomers, and mixtures containing these isomers may be used. Two or more compounds may also be used in combination. The dicarboxylic acids used in the present invention are not limited to the above-mentioned compounds.

[0098] A known synthesis method can be used to obtain a polyamic acid by reacting a diamine component with a tetracarboxylic dianhydride component. Generally, the method involves reacting a diamine component with a tetracarboxylic dianhydride component in an organic solvent.

[0099] The reaction between the diamine component and the tetracarboxylic dianhydride component is advantageous in that it proceeds relatively easily in an organic solvent and does not produce by-products.

[0100] The organic solvent used in the reaction is not particularly limited as long as it dissolves the produced polymer. Furthermore, even if the organic solvent does not dissolve the polymer, it may be mixed with the above solvent to the extent that the produced polymer does not precipitate. Note that, since water in the organic solvent inhibits the polymerization reaction and further causes hydrolysis of the produced polymer, it is preferable to use an organic solvent that has been dehydrated and dried.

[0101] Examples of organic solvents include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylformamide, N-methylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, N-methyl-ε-caprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, phosphoramide, γ-butyrolactone, isopropyl alcohol, and methoxymethylpentanol. ethanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol Pyrene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol tert-butyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 1,Examples of suitable organic solvents include 4-dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, and 2-ethyl-1-hexanol. These organic solvents may be used alone or in combination.

[0102] When the diamine component and the tetracarboxylic dianhydride component are reacted in an organic solvent, any of the following methods may be used: a method in which a solution in which the diamine component is dispersed or dissolved in an organic solvent is stirred, and the tetracarboxylic dianhydride component is added as is or after being dispersed or dissolved in an organic solvent; a method in which the diamine component is added to a solution in which the tetracarboxylic dianhydride component is dispersed or dissolved in an organic solvent; a method in which the tetracarboxylic dianhydride component and the diamine component are added alternately; etc. When the diamine component or the tetracarboxylic dianhydride component is composed of multiple types of compounds, the compounds may be reacted in a pre-mixed state, or may be reacted individually in sequence, or low-molecular-weight compounds that have been reacted individually may be mixed and reacted to form a high-molecular-weight compound.

[0103] The temperature at which the diamine component and the tetracarboxylic dianhydride component are reacted can be selected arbitrarily, for example, within the range of −20 to 100° C., preferably −5 to 80° C. The reaction can be carried out at any concentration, for example, the total amount of the diamine component and the tetracarboxylic dianhydride component relative to the reaction liquid is 1 to 50% by mass, preferably 5 to 30% by mass.

[0104] In the above polymerization reaction, the ratio of the total number of moles of the tetracarboxylic dianhydride components to the total number of moles of the diamine components can be selected arbitrarily depending on the molecular weight of the polyamic acid to be obtained. As in ordinary polycondensation reactions, the closer this molar ratio is to 1.0, the higher the molecular weight of the polyamic acid to be produced. The preferred range is 0.8 to 1.2.

[0105] The method for synthesizing the polymer as component (A) is not limited to the above-mentioned method. When synthesizing a polyamic acid, the corresponding polyamic acid can also be obtained by using a tetracarboxylic acid or a tetracarboxylic acid derivative such as a tetracarboxylic acid dihalide having a corresponding structure in place of the above-mentioned tetracarboxylic acid dianhydride and reacting the tetracarboxylic acid by a known method, as in a general method for synthesizing a polyamic acid.

[0106] Furthermore, polyimide can be obtained by ring-closing (imidizing) the polyamic acid. The imidization ratio referred to in this specification refers to the ratio of imide groups to the total amount of imide groups and carboxy groups derived from the tetracarboxylic dianhydride. The imidization ratio of polyimide does not necessarily need to be 100% and can be adjusted as desired depending on the application and purpose. The imidization ratio of polyimide is preferably 30% or more in order to increase the voltage holding ratio, while it is preferably 80% or less in order to prevent whitening, i.e., to suppress precipitation of the polymer in the varnish.

[0107] When the polyamic acid is thermally imidized in a solution, the temperature is usually 100 to 400° C., preferably 120 to 250° C., and it is preferable to carry out the imidization while removing water produced by the imidization reaction from the system.

[0108] Catalytic imidization of polyamic acid can be carried out by adding a basic catalyst and an acid anhydride to a polyamic acid solution and stirring the mixture at temperatures typically between -20 and 250°C, preferably between 0 and 180°C. The amount of basic catalyst is typically 0.5 to 30 times, and preferably 2 to 20 times, the molar ratio of amic acid groups, and the amount of acid anhydride is typically 1 to 50 times, and preferably 3 to 30 times, the molar ratio of amic acid groups. Examples of basic catalysts include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Of these, pyridine is preferred because it has adequate basicity for promoting the reaction. Examples of acid anhydrides include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Of these, acetic anhydride is preferred because it facilitates purification after the reaction. The imidization rate by catalytic imidization can be controlled by adjusting the catalyst amount, reaction temperature, reaction time, etc.

[0109] When recovering the produced polymer from a polymer reaction solution, the reaction solution may be poured into a poor solvent to cause precipitation. Examples of poor solvents used for precipitation include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, and water. The polymer precipitated by pouring into a poor solvent can be recovered by filtration and then dried at room temperature or by heating under atmospheric or reduced pressure. Furthermore, the polymer recovered by precipitation can be redissolved in an organic solvent and reprecipitated and recovered 2 to 10 times to reduce the amount of impurities in the polymer. Examples of poor solvents used in this process include alcohols, ketones, and hydrocarbons. Using three or more poor solvents selected from these solvents is preferred because it further increases the efficiency of purification.

[0110] The molecular weight of the polymer as component (A) is preferably 5,000 to 1,000,000, more preferably 10,000 to 150,000, in terms of weight average molecular weight measured by GPC (Gel Permeation Chromatography), taking into consideration the strength of the radical-generating film obtained by applying the radical-generating film-forming composition, the workability during film formation, the uniformity of the film, and the like.

[0111] <<Photosensitive side-chain acrylic polymer that exhibits liquid crystallinity within a specific temperature range>> One preferred embodiment of component (A) is a photosensitive side-chain acrylic polymer that exhibits liquid crystallinity within a specific temperature range. The side chain type acrylic polymer preferably reacts with light in the wavelength range of 250 to 400 nm and exhibits liquid crystallinity in the temperature range of 100 to 300°C. The side chain type acrylic polymer preferably has a photosensitive side chain that reacts to light in the wavelength range of 250 to 400 nm. The side chain type acrylic polymer preferably has a mesogenic group because it exhibits liquid crystallinity in the temperature range of 100 to 300°C.

[0112] The side-chain acrylic polymer has a photosensitive side chain bonded to its main chain, which can undergo a crosslinking reaction, an isomerization reaction, or a photo-induced Fries rearrangement in response to light. The structure of the photosensitive side chain is not particularly limited, but a structure that undergoes a crosslinking reaction or a photo-induced Fries rearrangement in response to light is desirable, and one that undergoes a crosslinking reaction is even more desirable. In this case, the realized alignment control ability can be stably maintained for a long period of time, even when exposed to external stress such as heat. The structure of the photosensitive side-chain acrylic polymer film that can exhibit liquid crystallinity is not particularly limited as long as it satisfies these properties, but it is preferable that the side-chain structure has a rigid mesogen component. In this case, when the side-chain acrylic polymer is used as a liquid crystal alignment film, stable liquid crystal alignment can be obtained.

[0113] The acrylic polymer may have a structure having, for example, a main chain and side chains bonded thereto, the side chains having a mesogen component such as a biphenyl group, a terphenyl group, a phenylcyclohexyl group, a phenylbenzoate group, or an azobenzene group, and a photosensitive group bonded to the tip that undergoes a crosslinking reaction or an isomerization reaction in response to light; or a structure having a main chain and side chains bonded thereto, the side chains also serving as mesogen components and having phenylbenzoate groups that undergo a photo-induced Fries rearrangement reaction.

[0114] More specific examples of the structure of the photosensitive side-chain acrylic polymer that exhibits liquid crystallinity within a predetermined temperature range preferably have a main chain composed of at least one radically polymerizable group selected from the group consisting of hydrocarbons, (meth)acrylates, itaconates, fumarates, maleates, α-methylene-γ-butyrolactone, styrenes, vinyls, maleimides, norbornenes, and the like, and a side chain composed of at least one of the following formulas (31) to (35). [ka] In the formula, Ar1 to Ar5 each independently represent a divalent substituent obtained by removing two hydrogen atoms from a benzene ring, a naphthalene ring, a pyrrole ring, a furan ring, a thiophene ring, or a pyridine ring; One of q1 and q2 is 1 and the other is 0, Y1-Y2 represent CH=CH, CH=N, N=CH or CC (wherein the carbon-carbon bond is a triple bond); S1 to S3 each independently represent a single bond, a linear or branched alkylene group having 1 to 18 carbon atoms, a cycloalkylene group having 5 to 8 carbon atoms, a phenylene group or a biphenylylene group, or represent one or more bonds selected from a single bond, an ether bond, an ester bond, an amide bond, a urea bond, a urethane bond, an amino bond, a carbonyl group or a combination thereof, or a structure in which 2 to 10 moieties selected from a linear or branched alkylene group having 1 to 18 carbon atoms, a cycloalkylene group having 5 to 8 carbon atoms, a phenylene group, a biphenylylene group or a combination thereof are bonded via the one or more bonds, and the substituents may each be a structure in which a plurality of them are linked via the bond; R 31 represents a hydrogen atom, a hydroxy group, a mercapto group, an amino group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylamino group having 1 to 8 carbon atoms, or a dialkylamino group having 2 to 16 carbon atoms, and the benzene ring and / or naphthalene ring may be substituted with one or more identical or different substituents selected from a halogen atom, a cyano group, a nitro group, a carboxy group, and an alkoxycarbonyl group having 2 to 11 carbon atoms. In this case, the alkyl group having 1 to 10 carbon atoms may be linear, branched, or cyclic, or may have a structure combining these, and the hydrogen atom of the alkyl group may be substituted with a halogen atom.

[0115] The photosensitive side-chain acrylic polymer that exhibits liquid crystallinity within a predetermined temperature range, which is one type of component (A) of the present invention, can contain a liquid crystalline side chain. The mesogenic group in the liquid crystalline side chain may be a group that forms a mesogenic structure by itself, such as a biphenyl structure or a phenylbenzoate structure, or a group that forms a mesogenic structure by hydrogen bonding between side chains, such as benzoic acid. The mesogenic group in the side chain preferably has the following structure: [ka]

[0116] <<<Production method of photosensitive side chain polymers>>> The photosensitive side chain acrylic polymer exhibiting liquid crystallinity within the above-mentioned predetermined temperature range can be obtained by polymerizing the above-mentioned photoreactive side chain monomer having a photosensitive side chain and a liquid crystalline side chain monomer.

[0117] [Photoreactive side chain monomer] The photoreactive side chain monomer is a monomer that, when formed into a polymer, can form a polymer having a photosensitive side chain at the side chain site of the polymer. The photoreactive group in the side chain preferably has a structure represented by the above formulas (31) to (35). More specific examples of photoreactive side chain monomers are preferably those having a structure in which a polymerizable group selected from the following PG1 to PG6 is bonded to a photosensitive side chain consisting of at least one of the above formulas (31) to (35). [ka] In the formula, M 1 represents a hydrogen atom or a methyl group.

[0118] [Liquid Crystalline Side Chain Monomers] The liquid crystalline side chain monomer is a monomer that allows a polymer derived from the monomer to exhibit liquid crystallinity and that can form a mesogen group at the side chain site. More specific examples of liquid crystalline side chain monomers are preferably those having a structure including a polymerizable group composed of at least one selected from the group consisting of radical polymerizable groups such as hydrocarbons, (meth)acrylates, itaconates, fumarates, maleates, α-methylene-γ-butyrolactone, styrenes, vinyls, maleimides, and norbornenes, and a side chain having at least one of the above-mentioned "mesogenic groups of liquid crystalline side chains."

[0119] The liquid crystalline side chain monomer is preferably a monomer in which a liquid crystalline side chain selected from the following formulae (1) to (12) is bonded to a polymerizable group selected from the above formulae PG1 to PG6. [ka] [ka] (In formulas (1) to (12), A 3 and A 4 each independently represents a single bond, -O-, -CH2-, -C(=O)-O-, -OC(=O)-, -C(=O)NH-, -NHC(=O)-, -CH=CH-C(=O)O-, or -OC(=O)-CH=CH-; R 11 represents -NO2, -CN, a halogen atom, a phenyl group, a naphthyl group, a biphenylyl group, a furanyl group, a monovalent nitrogen-containing heterocyclic group, a monovalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms; R 12 represents a group selected from the group consisting of a phenyl group, a naphthyl group, a biphenylyl group, a furanyl group, a monovalent nitrogen-containing heterocyclic group, a monovalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, and a group obtained by combining these, wherein a hydrogen atom bonded to the group may be substituted with -NO2, -CN, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms; R 13 represents a hydrogen atom, -NO2, -CN, -CH=C(CN)2, -CH=CH-CN, a halogen atom, a phenyl group, a naphthyl group, a biphenylyl group, a furanyl group, a monovalent nitrogen-containing heterocyclic group, a monovalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms; E represents -C(=O)O- or -OC(=O)-; d represents an integer of 1 to 12; k1 to k5 are each independently an integer of 0 to 2, but the sum of k1 to k5 in each formula is 2 or more; k6 and k7 are each independently an integer of 0 to 2, but the sum of k6 and k7 in each formula is 1 or more; m1, m2, and m3 are each independently an integer of 1 to 3; n is 0 or 1; Z 1 and Z 2 each independently represents a single bond, -C(=O)-, -CHO-, -CH=N-, or -CF-. A dashed line represents a bond.

[0120] The side-chain acrylic polymer, which is one embodiment of component (A), can be obtained by the polymerization reaction of the above-mentioned photoreactive side-chain monomer that exhibits liquid crystallinity. It can also be obtained by copolymerization of a photoreactive side-chain monomer that does not exhibit liquid crystallinity with a liquid-crystalline side-chain monomer, or by copolymerization of a photoreactive side-chain monomer that exhibits liquid crystallinity with a liquid-crystalline side-chain monomer. Furthermore, it can be copolymerized with other monomers as long as the ability to exhibit liquid crystallinity is not impaired.

[0121] Examples of other monomers include industrially available monomers capable of radical polymerization. Specific examples of other monomers include unsaturated carboxylic acids, acrylic acid ester compounds, methacrylic acid ester compounds, maleimide compounds, acrylonitrile, maleic anhydride, styrene compounds, and vinyl compounds. Specific examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, maleic acid, and fumaric acid. Examples of acrylic acid ester compounds include methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthryl acrylate, anthrylmethyl 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-tricyclo[5.2.1.0<2,6>]decyl acrylate, and 8-ethyl-8-tricyclo[5.2.1.0<2,6>]decyl acrylate. Examples of methacrylic acid ester compounds include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, benzyl methacrylate, naphthyl methacrylate, anthryl methacrylate, anthrylmethyl methacrylate, phenyl methacrylate, 2,2,2-trifluoroethyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2-ethoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 3-methoxybutyl methacrylate, 2-methyl-2-adamantyl methacrylate, 2-propyl-2-adamantyl methacrylate, 8-methyl-8-tricyclo[5.2.1.0<2,6>]decyl methacrylate, and 8-ethyl-8-tricyclo[5.2.1.0<2,6>]decyl methacrylate. (Meth)acrylate compounds having a cyclic ether group, such as glycidyl (meth)acrylate, (3-methyl-3-oxetanyl)methyl (meth)acrylate, and (3-ethyl-3-oxetanyl)methyl (meth)acrylate, can also be used. Examples of the vinyl compound include vinyl ether, methyl vinyl ether, benzyl vinyl ether, 2-hydroxyethyl vinyl ether, phenyl vinyl ether, and propyl vinyl ether. 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.

[0122] The method for producing the side-chain polymer is not particularly limited, and a general-purpose method used industrially can be used. Specifically, the polymer can be produced by cationic polymerization, radical polymerization, or anionic polymerization using the vinyl group of a liquid-crystalline side-chain monomer or a photoreactive side-chain monomer. Among these, radical polymerization is particularly preferred from the viewpoint of ease of reaction control.

[0123] As the polymerization initiator for radical polymerization, known radical polymerization initiators such as AIBN (azobisisobutyronitrile) and known compounds such as reversible addition-fragmentation chain transfer (RAFT) polymerization reagents can be used.

[0124] The radical polymerization method is not particularly limited, and may be an emulsion polymerization method, a suspension polymerization method, a dispersion polymerization method, a precipitation polymerization method, a bulk polymerization method, a solution polymerization method, or the like.

[0125] The organic solvent used in the polymerization reaction of a photosensitive side-chain acrylic polymer that exhibits liquid crystallinity within a predetermined temperature range is not particularly limited as long as it dissolves the produced polymer. Specific examples are listed below. N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methyl-ε-caprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, phosphoramide, γ-butyrolactone, isopropyl alcohol, methoxymethyl pentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene Dipropylene glycol tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 1,4-Dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, etc. These organic solvents may be used alone or in combination. Furthermore, even if a solvent does not dissolve the polymer to be produced, it may be mixed with the above-mentioned organic solvent to the extent that the polymer does not precipitate. In addition, since oxygen in an organic solvent inhibits the polymerization reaction in radical polymerization, it is preferable to use an organic solvent that has been degassed to the greatest extent possible.

[0126] The polymerization temperature during radical polymerization can be selected from any temperature between 30 and 150°C, but is preferably in the range of 50 to 100°C. The reaction can be carried out at any concentration, but if the concentration is too low, it becomes difficult to obtain a high-molecular-weight polymer, and if the concentration is too high, the reaction solution becomes too viscous, making uniform stirring difficult. Therefore, the monomer concentration is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The reaction can be carried out at a high concentration initially, and then an organic solvent can be added. In the above-mentioned radical polymerization reaction, if the ratio of the radical polymerization initiator to the monomer is high, the molecular weight of the resulting polymer will be small, and if it is low, the molecular weight of the resulting polymer will be large, so the ratio of the radical initiator to the monomer to be polymerized is preferably 0.1 to 10 mol %. Furthermore, various monomer components, solvents, initiators, etc. can also be added during polymerization.

[0127] To recover the resulting polymer from the reaction solution of a photosensitive side-chain polymer capable of exhibiting liquid crystallinity obtained by the above reaction, the reaction solution may be poured into a poor solvent to precipitate the polymer. Examples of poor solvents used for precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, and water. The polymer precipitated by pouring into the poor solvent can be recovered by filtration and then dried at room temperature or by heating under atmospheric or reduced pressure. Furthermore, the precipitated polymer can be redissolved in an organic solvent and reprecipitated and recovered 2 to 10 times to reduce the amount of impurities in the polymer. Examples of poor solvents include alcohols, ketones, and hydrocarbons. Using three or more poor solvents selected from these solvents is preferred because it further improves the efficiency of purification.

[0128] The molecular weight of the photosensitive side-chain acrylic polymer that exhibits liquid crystallinity within a predetermined temperature range, which is one embodiment of component (A) of the present invention, is preferably a weight-average molecular weight measured by GPC (Gel Permeation Chromatography) of 2,000 to 1,000,000, more preferably 5,000 to 100,000, taking into consideration the strength of the resulting coating film, the workability during coating film formation, and the uniformity of the coating film.

[0129] <Other ingredients> The radical-generating film-forming composition may contain other components such as a radical generator and an organic solvent in addition to the component (A) and the component (B). Examples of the radical generator include compounds that generate radicals when exposed to heat and compounds that generate radicals when exposed to light.

[0130] The compound that generates radicals when heated is a compound that generates radicals when heated to a temperature equal to or higher than its 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.), hydroperoxides (hydrogen peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyketals (dibutylperoxycyclohexane, etc.), alkyl peresters (peroxyneodecanoic acid-tert-butyl ester, peroxypivalic acid-tert-butyl ester, peroxy-2-ethylcyclohexanoic acid-tert-amyl ester, etc.), persulfates (potassium persulfate, sodium persulfate, ammonium persulfate, etc.), and azo compounds (azobisisobutyronitrile, 2,2′-bis(2-hydroxyethyl)azobisisobutyronitrile, etc.). Such radical thermal polymerization initiators can be used alone or in combination of two or more.

[0131] The compound that generates radicals when exposed to light 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 benzophenone, Michler's ketone, 4,4'-bis(diethylamino)benzophenone, xanthone, thioxanthone, isopropylxanthone, 2,4-diethylthioxanthone, 2-ethylanthraquinone, acetophenone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-2-methyl-4'-isopropylpropiophenone, 1-hydroxycyclohexylphenyl ketone, isopropyl benzoin ether, isobutyl benzoin ether, 2,2 -diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, camphorquinone, benzanthrone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,4-dimethylaminobenzoic acid ethyl ester, 4-dimethylaminobenzoic acid isoamyl ester, 4,4'-di(tert-butylperoxycarbonyl)benzophenone, 3,4,4'-tri(tert-butylperoxycarbonyl) ) Benzophenone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2-(4'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(3',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-pentyloxystyryl)-4, 6-Bis(trichloromethyl)-s-triazine, 1,3-bis(trichloromethyl)-5-(2'-chlorophenyl)-s-triazine, 1,3-bis(trichloromethyl)-5-(4'-methoxyphenyl)-s-triazine, 2-(p-dimethylaminostyryl)benzoxazole, 2-(p-dimethylaminostyryl)benzthiazole, 2-mercaptobenzothiazole, 3,3'-carbonylbis(7-diethylaminocoumarin), 2-(o-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-Biimidazole, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetrakis(4-ethoxycarbonylphenyl)-1,2'-biimidazole, 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4-dibromophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-biimidazole Bis(2,4,6-trichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 3-(2-methyl-2-dimethylaminopropionyl)carbazole, 3,6-bis(2-methyl-2-morpholinopropionyl)-9-n-dodecylcarbazole, 1-hydroxycyclohexyl phenyl ketone, bis(5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3- (1H-pyrrol-1-yl)-phenyl)titanium, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, 3,3',4,4'-tetra(tert-hexylperoxycarbonyl)benzophenone, 3,3'-di(methoxycarbonyl)-4,4'-di(tert-butylperoxycarbonyl)benzophenone, 3,4'-di(methoxycarbonyl)-4,3'-di(t Examples of the benzophenone include 4,4'-di(tert-butylperoxycarbonyl)benzophenone, 4,4'-di(methoxycarbonyl)-3,3'-di(tert-butylperoxycarbonyl)benzophenone, 2-(3-methyl-3H-benzothiazol-2-ylidene)-1-naphthalen-2-yl-ethanone, and 2-(3-methyl-1,3-benzothiazol-2(3H)-ylidene)-1-(2-benzoyl)ethanone. These compounds may be used alone or in combination of two or more.

[0132] The radical-generating film-forming composition may contain an organic solvent for dissolving or dispersing the polymer component, and optionally the radical generator and other components. There are no particular limitations on the organic solvent, and examples include the organic solvents exemplified in the synthesis of the polyamic acid described above. Among these, N-methyl-2-pyrrolidone, γ-butyrolactone, N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and 3-methoxy-N,N-dimethylpropanamide are preferred from the viewpoint of solubility. N-methyl-2-pyrrolidone or N-ethyl-2-pyrrolidone is particularly preferred, but a mixed solvent of two or more of these may also be used.

[0133] It is also preferable to use a solvent that improves the uniformity and smoothness of the coating film by mixing it with an organic solvent that has high solubility for the components contained in the radical-generating film-forming composition.

[0134] Examples of solvents that improve the uniformity and smoothness of the coating film include isopropyl alcohol, methoxymethyl pentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve (ethylene glycol monobutyl ether), methyl cellosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether, ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, n-hexyl ethanol, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 1-methoxy-2-propanol,Examples of suitable solvents include 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy)propanol, and 2-ethyl-1-hexanol. These solvents may be mixed in combination. When these solvents are used, their content is preferably 5 to 80 mass %, more preferably 20 to 60 mass %, of the total solvent contained in the radical-generating film-forming composition.

[0135] The radical-generating film-forming composition may contain components other than those described above, such as compounds that improve the film thickness uniformity and surface smoothness when the radical-generating film-forming composition is applied, compounds that improve the adhesion between the radical-generating film-forming composition and the substrate, and compounds that further improve the film strength of the radical-generating film-forming composition.

[0136] Compounds that improve film thickness uniformity and surface smoothness include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants. More specific examples include Eftop EF301, EF303, and EF352 (manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), Megafac F171, F173, and R-30 (manufactured by DIC Corporation), Fluorad FC430 and FC431 (manufactured by 3M), Asahiguard AG710 (manufactured by AGC Corporation), and Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (manufactured by AGC Seimi Chemical Co., Ltd.). When these surfactants are used, the amount used is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, per 100 parts by mass of the total amount of polymers contained in the radical-generating film-forming composition.

[0137] Specific examples of compounds that improve the adhesion between the radical-generating film-forming composition and the substrate include functional silane-containing compounds and epoxy group-containing compounds. 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-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxy ... -Aminopropyltriethoxysilane, N-(3-triethoxysilylpropyl)triethylenetetramine, N-(3-trimethoxysilylpropyl)triethylenetetramine, 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-aminopropyl N-phenyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether , dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, 3-(N-allyl-N-glycidyl)aminopropyltrimethoxysilane, and 3-(N,N-diglycidyl)aminopropyltrimethoxysilane.

[0138] To further increase the film strength of the radical-generating film, phenolic compounds such as 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane and tetra(methoxymethyl)bisphenol may be added. When using these compounds, the amount is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of the total amount of polymers contained in the radical-generating film-forming composition.

[0139] Furthermore, in addition to the above, the radical-generating film-forming composition may contain a dielectric or conductive substance for the purpose of changing the electrical properties, such as the dielectric constant and conductivity, of the radical-generating film, as long as the effects of the present invention are not impaired.

[0140] [Radical generating film] The radical-generating film of the present invention can be obtained using the radical-generating film-forming composition. For example, the radical-generating film-forming composition used in the present invention can be applied to a substrate, followed by drying and baking to obtain a cured film, which can be used as is as a radical-generating film. Furthermore, this cured film can be subjected to alignment treatment by rubbing, irradiation with polarized light or light of a specific wavelength, or treatment with an ion beam, and the liquid crystal display element can also be irradiated with UV (ultraviolet) light after filling with liquid crystal.

[0141] The substrate onto which the radical-generating film-forming composition is applied is not particularly limited as long as it is a highly transparent substrate, but a substrate on which a transparent electrode for driving a liquid crystal is formed is preferred.

[0142] Specific examples include substrates on which a transparent electrode is formed, such as a glass plate, or a plastic plate made of polycarbonate, poly(meth)acrylate, polyethersulfone, polyarylate, polyurethane, polysulfone, polyether, polyetherketone, trimethylpentene, polyolefin, polyethylene terephthalate, (meth)acrylonitrile, triacetyl cellulose, diacetyl cellulose, or acetate butyrate cellulose.

[0143] Substrates that can be used in IPS-type liquid crystal display elements can have electrode patterns such as standard IPS comb electrodes and PSA fishbone electrodes, as well as protrusion patterns such as MVA.

[0144] Furthermore, in a highly functional element such as a TFT type element, an element such as a transistor is formed between an electrode for driving the liquid crystal and a substrate.

[0145] When a transmissive liquid crystal display element is intended, the above-mentioned substrates are generally used, but when a reflective liquid crystal display element is intended, an opaque substrate such as a silicon wafer can be used for only one of the substrates. In this case, a light-reflecting material such as aluminum can be used for the electrodes formed on the substrate.

[0146] Examples of methods for applying the radical-generating film-forming composition include spin coating, printing, inkjet printing, spraying, and roll coating. From the viewpoint of productivity, transfer printing is widely used industrially and is also preferably used in the present invention.

[0147] Although a drying step is not necessarily required after coating the radical-generating film-forming composition, it is preferable to include a drying step when the time from coating to baking is not constant for each substrate, or when baking is not performed immediately after coating. This drying step is sufficient as long as the solvent is removed to an extent that the coating film shape does not deform when the substrate is transported, and the drying method is not particularly limited. For example, a method of drying on a hot plate at a temperature of 40 to 150°C, preferably 60 to 100°C, for 0.5 to 30 minutes, preferably 1 to 5 minutes, can be used.

[0148] The coating film formed by applying the radical-generating film-forming composition using the above method can be baked to form a cured film. The baking temperature can be any temperature between 100 and 350°C, preferably between 140 and 300°C, more preferably between 150 and 230°C, and even more preferably between 160 and 220°C. The baking time can be any time between 5 and 240 minutes, preferably between 10 and 90 minutes, and more preferably between 20 and 90 minutes. Heating can be performed using any known method, such as a hot plate, a hot air circulation oven, an IR (infrared) oven, or a belt furnace.

[0149] The thickness of the cured film can be selected as needed, but is preferably 5 nm or more, more preferably 10 nm or more, since this improves the reliability of the liquid crystal display element. Also, the thickness of the cured film is preferably 300 nm or less, more preferably 150 nm or less, since this prevents the power consumption of the liquid crystal display element from becoming extremely large.

[0150] The first substrate having the radical-generating film can be obtained in the above manner, and the radical-generating film can be subjected to uniaxial alignment treatment. Methods for uniaxial alignment treatment include photoalignment, oblique deposition, rubbing, and uniaxial alignment treatment using a magnetic field.

[0151] When performing alignment treatment by unidirectional rubbing, for example, a rubbing roller wrapped with a rubbing cloth is rotated while the substrate is moved so that the rubbing cloth comes into contact with the film. When using a photoalignment method, alignment treatment can be performed by irradiating the entire film with polarized UV of a specific wavelength and heating it as necessary. In the case of the first substrate of the present invention on which a comb-tooth electrode is formed, the direction is selected depending on the electrical properties of the liquid crystal, but when a liquid crystal having positive dielectric anisotropy is used, it is preferable that the rubbing direction be approximately the same as the direction in which the comb-tooth electrode extends.

[0152] A method of irradiating radiation in a desired pattern through a photomask or the like can be used as a process for creating weak anchoring portions and strong anchoring portions. This is a process in which the radical-generating film is irradiated with radiation in advance to eliminate radical-generating sites and prevent a weak anchoring state. Examples of radiation used in this process include polarized light or light of a specific wavelength, and ion beams. It is particularly preferable to irradiate light of a wavelength that maximizes the absorbance of the portion corresponding to the photoradical-generating site.

[0153] The second substrate of the present invention may or may not have a radical-generating film, but is preferably a substrate having a conventionally known liquid crystal alignment film.

[0154] In the present invention, the first substrate may be a substrate having a comb-teeth electrode and the second substrate may be a counter substrate. Also, in the present invention, the second substrate may be a substrate having a comb-teeth electrode and the first substrate may be a counter substrate.

[0155] [Liquid crystal cell] The liquid crystal cell of the present invention can be obtained by forming a radical-generating film on a substrate by the above-described method, then arranging a substrate having the radical-generating film (first substrate) and a substrate having a known liquid crystal alignment film (second substrate) so that the radical-generating film and the liquid crystal alignment film face each other, sandwiching a spacer between them, fixing them with a sealant, injecting a liquid crystal composition containing liquid crystal and a radically polymerizable compound, and sealing it. The size of the spacer used here is usually 1 to 30 μm, but preferably 2 to 10 μm. Furthermore, by arranging the rubbing direction of the first substrate parallel to that of the second substrate, the cell can be used in IPS mode or FFS mode, and by arranging the rubbing directions perpendicular to each other, the cell can be used in twisted nematic mode. An IPS substrate, which is a comb electrode substrate used in IPS (In-Plane Switching) mode, has a base material, a plurality of linear electrodes formed on the base material and arranged in a comb-teeth shape, and a liquid crystal alignment film formed on the base material so as to cover the linear electrodes. The FFS substrate, which is a comb electrode substrate used in the FFS (Field Switching) mode, has a base material, a surface electrode formed on the base material, an insulating film formed on the surface electrode, a plurality of linear electrodes formed on the insulating film and arranged in a comb-like pattern, and a liquid crystal alignment film formed on the insulating film so as to cover the linear electrodes.

[0156] The method for injecting the liquid crystal composition containing the liquid crystal and the radical polymerizable compound is not particularly limited, and examples thereof include a vacuum method in which the pressure inside the prepared liquid crystal cell is reduced and then a mixture containing the liquid crystal and the polymerizable compound is injected, and a dropping method in which a mixture containing the liquid crystal and the polymerizable compound is dropped and then sealed.

[0157] <Radical polymerizable compound and liquid crystal composition> In producing the liquid crystal display element of the present invention, the polymerizable compound used together with the liquid crystal is not particularly limited as long as it is a radically polymerizable compound, but for example, it is a compound having one or more polymerizable reactive groups in one molecule. Preferably, it is a compound having one polymerizable reactive group in one molecule (hereinafter, sometimes referred to as a "compound having a monofunctional polymerizable group" or a "compound having a monofunctional polymerizable group"). The polymerizable reactive group is preferably a radically polymerizable reactive group, such as a vinyl bond.

[0158] At least one of the radically polymerizable compounds is preferably a compound having compatibility with the liquid crystal and having one polymerizable reactive group in one molecule, that is, a compound having a monofunctional radically polymerizable group.

[0159] The radically polymerizable group M of the radically polymerizable compound is preferably a polymerizable group selected from the following structures. [ka] (where * indicates a binding site. R b represents a linear alkyl group having 2 to 8 carbon atoms, and E represents a single bond, -O-, or -NR c R represents a bonding group selected from -, -S-, an ester bond, and an amide bond.c represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. d represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0160] The radical polymerizable compound has an unsaturated bond capable of undergoing radical polymerization in the presence of an organic radical, and examples thereof include methacrylate monomers such as tert-butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, lauryl methacrylate, and n-octyl methacrylate; acrylate monomers such as tert-butyl acrylate, benzyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, lauryl acrylate, and n-octyl acrylate; styrene and styrene derivatives (e.g., o-, m-, and p-methoxystyrene, o-, m-, and p-tert-butoxy ... Examples of suitable vinyl monomers include, but are not limited to, vinyl monomers such as vinyl esters (e.g., vinyl acetate, vinyl propionate, vinyl benzoate), vinyl ketones (e.g., vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone), N-vinyl compounds (e.g., N-vinylpyrrolidone, N-vinylpyrrole, N-vinylcarbazole, N-vinylindole), (meth)acrylic acid derivatives (e.g., acrylonitrile, methacrylonitrile, acrylamide, isopropylacrylamide, methacrylamide), and vinyl halides (e.g., vinyl chloride, vinylidene chloride, tetrachloroethylene, hexachloroprene, vinyl fluoride). These various radically polymerizable monomers may be used alone or in combination of two or more. It is also preferable that they are compatible with the liquid crystal.

[0161] Furthermore, the radical polymerizable compound is preferably a compound represented by the following formula (Z): [ka] (In formula (Z), R a and Rb each independently represents a linear alkyl group having 2 to 8 carbon atoms, and E represents a single bond, -O-, or -NR c R represents a linking group selected from -, -S-, an ester bond, and an amide bond. c represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0162] A more preferred example of the radical polymerizable compound used in the present invention is represented by the following formula (A). [ka]

[0163] (In formula (A), M represents a radically polymerizable group; R1 to R3 each independently represent a single bond or an alkylene group having 1 to 6 carbon atoms, into which a bonding group may be inserted; Ar represents an aromatic hydrocarbon group which may have a substituent; X1 and X2 each independently represent a hydrogen atom or an aromatic hydrocarbon group which may have a substituent; and R1X1, R2X2 and the carbon atoms bonding to R1X1 and R2X2 may be joined together to form a ring, provided that the total number of carbon atoms in R1X1, R2X2 and R3 is 1 or more.)

[0164] By using the radical polymerizable compound represented by formula (A), it is possible to stably produce weak anchoring IPS LCD elements without generating a pretilt angle even when the cell gap is narrowed, and it is possible to simultaneously achieve a low driving voltage and a fast response speed when the voltage is off. In addition, it is possible to produce IPS LCD elements with little deterioration in VHR even at high temperatures. The inventors believe that the radical polymerizable compound represented by formula (A) contributes to this as follows. M of the radical polymerizable compound represented by formula (A) contributes to the radical polymerization of the radical polymerizable compound, thereby forming a weak anchoring film and realizing a low driving voltage. The inventors also speculate that Ar (an aromatic hydrocarbon group which may have a substituent) of the radical polymerizable compound represented by formula (A) contributes to suppressing the generation of a pretilt angle, improving the response speed, and achieving a high VHR at high temperatures. Furthermore, the present inventors speculate that in formula (A), the fact that M and Ar are not too close and that a group of a certain size [—C(R1X1)(R2X2)R3—] is present between M and Ar has the effect of further increasing the response speed. In this specification, a narrow cell gap means a cell gap of 3.5 μm or less.

[0165] In formula (A), the alkylene group having 1 to 6 carbon atoms and having a bonding group inserted therein means a divalent group in which a bonding group is inserted between carbon atoms within the alkylene group having 1 to 6 carbon atoms, or a divalent group in which a bonding group is inserted between the alkylene group having 1 to 6 carbon atoms and the carbon atom bonding thereto. Examples of the linking group include a carbon-carbon unsaturated bond, an ether bond (-O-), an ester bond (-COO- or -OCO-), an amide bond (-CONH- or -NHCO-), etc. Examples of the unsaturated bond include a carbon-carbon double bond, but it is preferable that the alkylene group having 1 to 6 carbon atoms into which the linking group is inserted has a carbon-carbon double bond inside the group rather than at its terminal. Examples of the alkylene group having 1 to 6 carbon atoms and optionally having a bonding group include an alkylene group having 1 to 6 carbon atoms and an oxyalkylene group having 1 to 6 carbon atoms. The oxygen atom in the oxyalkylene group having 1 to 6 carbon atoms is bonded to, for example, the carbon atoms bonded to M, R1, R2, and R3 in formula (A). The alkylene group having 1 to 6 carbon atoms may be a linear alkylene group, a branched alkylene group, or a cyclic alkylene group.

[0166] In the formula (A), examples of the aromatic hydrocarbon group which may have a substituent include a phenyl group and a naphthyl group which may have a substituent. Examples of the substituent include a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogenated alkyl group having 1 to 4 carbon atoms, and a halogenated alkoxy group having 1 to 4 carbon atoms. The halogenated alkyl group and the halogenated alkoxy group may be completely halogenated or may be partially halogenated. Examples of the halogen atom include a fluorine atom and a chlorine atom.

[0167] In formula (A), examples of R1 include a single bond and an alkylene group having 1 to 6 carbon atoms. More specific examples of the alkylene group having 1 to 6 carbon atoms include linear alkylene groups having 1 to 6 carbon atoms. In formula (A), examples of R2 include a single bond and an alkylene group having 1 to 6 carbon atoms. More specific examples of the alkylene group having 1 to 6 carbon atoms include linear alkylene groups having 1 to 6 carbon atoms. In formula (A), examples of R3 include a single bond and an alkylene group having 1 to 6 carbon atoms. More specific examples of the alkylene group having 1 to 6 carbon atoms include linear alkylene groups having 1 to 6 carbon atoms. In the formula (A), examples of X1 include a hydrogen atom and a phenyl group. In the formula (A), examples of X2 include a hydrogen atom and a phenyl group. In formula (A), A r is, for example, a phenyl group.

[0168] In formula (A), the total number of carbon atoms in R1X1, R2X2 and R3 is not particularly limited as long as it is 1 or more, but may be 2 or more. Also, R1, R 2、 and R3 may have a total carbon number of, for example, 18 or less, 15 or less, or 10 or less. When X1 and X2 are hydrogen atoms, R1 and R 2、 The total number of carbon atoms of R and R3 is not particularly limited as long as it is 1 or more, but may be 2 or more. In addition, when at least one of X1 and X2 is an aromatic hydrocarbon group which may have a substituent, R1, R 2、 The total number of carbon atoms in R3 may be 0.

[0169] Examples of the ring formed by R1X1, R2X2, and the carbon atoms bonded to R1X1 and R2X2 together include a hydrocarbon ring having 3 to 13 carbon atoms, into which a bonding group may be inserted. The bonding group is as described above.

[0170] Examples of the radical polymerizable compounds included in the formula (A) and formula (A-1) include the following radical polymerizable compounds.

[0171] Examples of the radical polymerizable compound represented by formula (A) include radical polymerizable compounds represented by the following formulae (A-1) to (A-3). [ka] In the formula, M represents a polymerizable group capable of radical polymerization. R1 to R3 each independently represent a single bond or an alkylene group having 1 to 6 carbon atoms which may have a bonding group inserted therein; Ar, Ar1, and Ar2 each independently represent an aromatic hydrocarbon group which may have a substituent; R 11 and R 12 each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms into which a bonding group may be inserted. In formula (A-1), R 11 and R 12 and R 11 and R 12 and the carbon atom bonded to may be taken together to form a ring. In formula (A-1), R 11 , R 12 and R3 have a total carbon number of 1 or more, and may be 2 or more. In addition, the total carbon number may be 18 or less, 15 or less, or 10 or less. In formula (A-2), R1, R 12The total number of carbon atoms in R and R3 is not particularly limited and may be 0. The total number of carbon atoms may be, for example, 18 or less, 15 or less, or 10 or less. In formula (A-3), the total number of carbon atoms in R1, R2, and R3 is not particularly limited and may be 0. The total number of carbon atoms may be, for example, 18 or less, 15 or less, or 10 or less. In addition, R 11 is when X1 is a hydrogen atom in R1X1. 12 is the case where X2 in R2X2 is a hydrogen atom.

[0172] Examples of the radical polymerizable compounds included in the formula (A) and formula (A-1) include the following radical polymerizable compounds. [ka]

[0173] Another preferred example of the radical polymerizable compound used in the present invention is represented by the following formula (A'). [ka] (In formula (A'), M represents a radically polymerizable group, R1 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms and having a linear or branched structure, and three Xs each independently represent a hydrogen atom or the following formula (B'), provided that at least one of the three Xs represents formula (B').) [ka] (In formula (B'), Y represents a single bond, -O-, -S-, or -NR-; R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; and * represents a bonding site. R2, R3, and R4 each independently represent an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group which may have a substituent.)

[0174] By using the radical polymerizable compound represented by formula (A'), it is possible to stably produce a weak anchoring IPS LCD element without generating a pretilt angle even when the cell gap is narrowed, and it is possible to simultaneously achieve a low driving voltage and a fast response speed when the voltage is off. In addition, it is possible to produce an IPS LCD element with little deterioration in VHR even at high temperatures. The inventors believe that the radical polymerizable compound represented by formula (A') contributes to this as follows. M of the radical polymerizable compound represented by formula (A') contributes to the radical polymerization of the radical polymerizable compound, thereby forming a weak anchoring film and realizing a low driving voltage. The present inventors also speculate that -SiR2R3R4 in the radical polymerizable compound represented by formula (A') contributes to suppressing the occurrence of a pretilt angle, improving response speed, and achieving a high VHR at high temperatures.

[0175] The aliphatic hydrocarbon group in R1 of formula (A') has 1 to 10 carbon atoms, and may have 1 to 8 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms.

[0176] The alkyl group having 1 to 6 carbon atoms in R2, R3, and R4 of formula (A') may be, for example, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 4 carbon atoms. These alkyl groups may have a linear structure or a branched structure.

[0177] The aromatic hydrocarbon groups in R2, R3, and R4 of formula (A') may be unsubstituted, or a hydrogen atom may be substituted with a substituent. Examples of the substituent of the aromatic hydrocarbon group which may have a substituent include a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogenated alkyl group having 1 to 4 carbon atoms, and a halogenated alkoxy group having 1 to 4 carbon atoms. The halogenated alkyl group and the halogenated alkoxy group may be fully halogenated or may be partially halogenated. Examples of the halogen atom include a fluorine atom and a chlorine atom. Examples of the aromatic hydrocarbon group in the aromatic hydrocarbon group which may have a substituent include a phenyl group and a naphthyl group. The number of substituents in the aromatic hydrocarbon group is not particularly limited.

[0178] In the radical polymerizable compound represented by formula (A'), the number of groups represented by formula (B') is one or more, and may be one, two, or three. In the radical polymerizable compound represented by formula (A'), three X's are independent of each other. Therefore, when the radical polymerizable compound represented by formula (A') has two or more groups represented by formula (B'), the two or more groups represented by formula (B') may have the same structure or different structures.

[0179] In formula (B'), at least one of R2, R3, and R4 may be an aromatic hydrocarbon group which may have a substituent. Therefore, in formula (B'), one of R2, R3, and R4 may be an aromatic hydrocarbon group which may have a substituent, two of R2, R3, and R4 may be aromatic hydrocarbon groups which may have a substituent, or three of R2, R3, and R4 may be aromatic hydrocarbon groups which may have a substituent.

[0180] Examples of the radical polymerizable compound represented by formula (A') include radical polymerizable compounds that satisfy the following (I) to (III). (I): In formula (A'), M represents the following structure (C') or structure (D'), R1 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms and having a linear or branched structure, and three Xs each independently represent a hydrogen atom or formula (B'), provided that at least one of the three Xs represents formula (B'). (II): In formula (B'), Y represents -O-, and * represents a bonding site. R2, R3, and R4 each independently represent an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group which may have a substituent. However, at least one of R2, R3, and R4 represents an aromatic hydrocarbon group which may have a substituent. (III): The compound is not a radical polymerizable compound represented by the following formula (E'). [ka]

[0181] Examples of the radical polymerizable compound included in formula (A') include the following radical polymerizable compounds. [ka]

[0182] The liquid crystal composition contains at least a liquid crystal and the radically polymerizable compound. The content of the radically polymerizable compound in the liquid crystal composition is preferably 0.5% by mass or more, more preferably 1% by mass or more, and preferably 10% by mass or less, more preferably 5% by mass or less, relative to the total mass of the liquid crystal and the radically polymerizable compound.

[0183] In addition, in the liquid crystal composition, in addition to the above radical polymerizable compound, multiple compounds having other monofunctional radical polymerizable groups (hereinafter sometimes referred to as "other radical polymerizable compounds") may be used in combination.

[0184] At least one of the radically polymerizable compounds contained in the liquid crystal composition is preferably a compound that is compatible with the liquid crystal and has one polymerizable unsaturated bond in one molecule, i.e., a compound that has a monofunctional radically polymerizable group.

[0185] As the radical polymerizable compound represented by formula (Z), one in which E in the formula is an ester bond (a bond represented by -C(=O)-O- or -OC(=O)-) is preferred from the viewpoints of ease of synthesis, compatibility with liquid crystal, and polymerization reactivity. Specifically, compounds represented by the following structures are preferred, but there are no particular limitations thereon. [ka]

[0186] The liquid crystal composition preferably contains a radically polymerizable compound that allows the Tg of the polymer obtained by polymerizing the radically polymerizable compound to be 100° C. or less.

[0187] These various radical polymerizable monomers may be used alone or in combination of two or more kinds, and preferably have compatibility with the liquid crystal.

[0188] The polymer obtained by polymerizing the radically polymerizable compound preferably has a Tg of 100°C or lower, more preferably 0°C or lower.

[0189] Liquid crystal generally refers to a substance that exhibits both solid and liquid properties, and typical liquid crystal phases include nematic liquid crystal and smectic liquid crystal, but the liquid crystal that can be used in the present invention is not particularly limited. One example is 4-pentyl-4'-cyanobiphenyl.

[0190] Next, a liquid crystal cell containing the mixture (liquid crystal composition) containing the liquid crystal and the radically polymerizable compound is supplied with sufficient energy to polymerize the radically polymerizable compound. This can be achieved, for example, by applying heat or UV irradiation, and the radically polymerizable compound is polymerized in situ, thereby exhibiting the desired properties. Among these, UV irradiation is preferred because it enables alignment patterning and allows the polymerization reaction to occur in a short time.

[0191] The heating temperature during UV irradiation is preferably within a temperature range in which the introduced liquid crystal exhibits liquid crystallinity, and is usually 40°C or higher, but is preferably below the temperature at which the liquid crystal changes to an isotropic phase.

[0192] When UV irradiation is performed, it is preferable to select a wavelength that provides the best reaction quantum yield of the polymerizable compound to be reacted, and the UV irradiation dose is usually 0.01 to 30 J / cm. 2 However, preferably, 10 J / cm 2 A lower UV exposure amount is preferable because it can prevent deterioration in reliability due to damage to the components that make up the liquid crystal display, and also because it can improve manufacturing takt time by reducing the UV exposure time.

[0193] When polymerization is carried out by heating alone, rather than by UV irradiation, the heating is preferably carried out at a temperature within a range where the polymerizable compound reacts but is lower than the decomposition temperature of the liquid crystal, specifically, 100 to 150°C.

[0194] When applying sufficient energy to cause the radical polymerizable compound to undergo a polymerization reaction, it is preferable that no voltage is applied and that the state is in a field-free state.

[0195] [Method for manufacturing a liquid crystal display element, and a liquid crystal display element] A liquid crystal display device can be produced using the liquid crystal cell thus obtained. The method for manufacturing a liquid crystal display element includes, for example, the following steps (1) to (4). (1) A step of preparing a first substrate having a radical-generating film of the present invention and a second substrate which may have a radical-generating film. (2) A step of arranging the first substrate and the second substrate so that the radical generating film on the first substrate faces the second substrate. (3) filling a liquid crystal composition containing a liquid crystal and a radical polymerizable compound between the first substrate and the second substrate; (4) A step of polymerizing the radical-polymerizable compound while the liquid crystal composition is in contact with the radical-generating film. The liquid crystal display element has, for example, a first substrate, a second substrate disposed opposite the first substrate, and liquid crystal filled between the first and second substrates, and is produced by bringing a liquid crystal composition containing liquid crystal and a radical-polymerizable compound into contact with the radical-generating film of the first substrate having the radical-generating film of the present invention, and polymerizing the radical-polymerizable compound. The liquid crystal display element can be made into a reflective liquid crystal display element by, for example, providing a reflective electrode, a transparent electrode, a λ / 4 plate, a polarizing film, a color filter layer, etc. to the liquid crystal cell according to a conventional method, as needed, or a transmissive liquid crystal display element by providing a backlight, a polarizing plate, a λ / 4 plate, a transparent electrode, a polarizing film, a color filter layer, etc. to the liquid crystal cell according to a conventional method, as needed.

[0196] The second substrate may be a second substrate that does not have a radical-generating film. The second substrate may be a substrate coated with a liquid crystal alignment film having uniaxial alignment properties, and the liquid crystal alignment film having uniaxial alignment properties may be a liquid crystal alignment film for horizontal alignment.

[0197] In the liquid crystal display element manufacturing method and the liquid crystal display element, for example, either the first substrate or the second substrate is a substrate having a comb-teeth electrode.

[0198] FIG. 1 is a schematic cross-sectional view showing an example of an in-plane switching liquid crystal display element of the present invention, which is an example of an IPS mode liquid crystal display element. In the IPS LCD element 1 shown in FIG. 1, liquid crystal 3 is sandwiched between a comb electrode substrate 2 having a liquid crystal alignment film 2c and a counter substrate 4 having a liquid crystal alignment film 4a. The comb electrode substrate 2 has a base material 2a, a plurality of linear electrodes 2b formed on the base material 2a and arranged in a comb-like pattern, and a liquid crystal alignment film 2c formed on the base material 2a to cover the linear electrodes 2b. The counter substrate 4 has a base material 4b and a liquid crystal alignment film 4a formed on the base material 4b. The liquid crystal alignment film 2c is a weak anchoring film obtained, for example, by chemically modifying a radical-generating film. The liquid crystal alignment film on the comb electrode substrate side is obtained, for example, by bringing a liquid crystal composition containing liquid crystal and a radical-polymerizable compound into contact with the radical-generating film and polymerizing the radical-polymerizable compound. In this IPS LCD element 1, when a voltage is applied to the linear electrodes 2b, an electric field is generated between the linear electrodes 2b as indicated by electric force lines L.

[0199] FIG. 2 is a schematic cross-sectional view showing another example of the in-plane switching liquid crystal display element of the present invention, which is an example of an FFS mode liquid crystal display element. In the IPS LCD element 1 shown in FIG. 2, liquid crystal 3 is sandwiched between a comb-shaped electrode substrate 2 having a liquid crystal alignment film 2h and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 includes a base material 2d, a surface electrode 2e formed on the base material 2d, an insulating film 2f formed on the surface electrode 2e, a plurality of linear electrodes 2g formed on the insulating film 2f and arranged in a comb-like pattern, and a liquid crystal alignment film 2h formed on the insulating film 2f to cover the linear electrodes 2g. The counter substrate 4 includes a base material 4b and a liquid crystal alignment film 4a formed on the base material 4b. The liquid crystal alignment film 2h is a weak anchoring film obtained, for example, by chemically modifying a radical-generating film. The liquid crystal alignment film on the comb-shaped electrode substrate side is obtained, for example, by bringing a liquid crystal composition containing liquid crystal and a radical-polymerizable compound into contact with the radical-generating film and polymerizing the radical-polymerizable compound. In this IPS LCD element 1, when a voltage is applied to the surface electrodes 2e and the linear electrodes 2g, an electric field is generated between the surface electrodes 2e and the linear electrodes 2g as indicated by electric force lines L. [Example]

[0200] The present invention will be specifically described below with reference to examples, but the present invention should not be construed as being limited to these examples. The abbreviations of the compounds and the methods for measuring the respective properties are as follows.

[0201] (diamine) DA-1 to DA-4: Compounds represented by the following formulas (DA-1) to (DA-4) [ka] [ka]

[0202] (Tetracarboxylic acid dianhydride) TC-1: A compound represented by the following formula (TC-1) [ka]

[0203] (additives) Add-1: a compound represented by the following formula (Add-1): Add-P1 to Add-P3: compounds represented by the following formulae (Add-P1) to (Add-P3), respectively [ka]

[0204] (solvent) NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve THF: tetrahydrofuran (Reactant) TEA: Triethylamine AIBN: Azobisisobutyronitrile DMAP: 4-dimethylaminopyridine

[0205] <Viscosity measurement> The viscosity of the polyamic acid solution was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample volume of 1.1 mL (milliliters), a cone rotor TE-1 (1°34', R24), and a temperature of 25°C. <Molecular weight measurement> The molecular weights of the polyimide precursor and polyimide were measured using a room temperature gel permeation chromatography (GPC) apparatus (GPC-101) (manufactured by Showa Denko K.K.) and columns (GPC KD-803, GPC KD-805) (manufactured by Showa Denko K.K.) as follows. Column temperature: 50℃ Eluent: N,N-dimethylformamide (additives: lithium bromide monohydrate (LiBr·HO) 30 mmol / L, phosphoric acid anhydrous crystal (o-phosphoric acid) 30 mmol / L, tetrahydrofuran (THF) 10 mL / L) Flow rate: 1.0mL / min Standard samples for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight: approximately 900,000, 150,000, 100,000, and 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight: approximately 12,000, 4,000, and 1,000) (manufactured by Polymer Laboratory Co., Ltd.).

[0206] <Synthesis Example 1: Synthesis of 2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl methacrylate> [ka]

[0207] A 300 mL four-neck flask equipped with a stirrer was charged with 2-hydroxy-1-(4-(2-hydroxyethoxy)phenyl)-2-methylpropan-1-one (20.0 g, 89.2 mmol), THF (200 g), and TEA (10.8 g, 107 mmol). While stirring in an ice bath, methacryloyl chloride (10.3 g, 98.1 mmol) was slowly added dropwise. After the addition, the mixture was returned to room temperature and reacted for 12 hours. After confirming the completion of the reaction by HPLC, ethyl acetate (100 mL) was added, and the precipitate was removed by filtration. The mixture was then washed with purified water (100 mL) and saturated brine (100 mL), and dried over anhydrous magnesium sulfate. After removing the anhydrous magnesium sulfate by filtration, the solvent was removed using a rotary evaporator to obtain a crude product. Purification was carried out by column chromatography (developing solvent: ethyl acetate / hexane = 2 / 8 volume ratio), and the solvent was removed to obtain the target product (21.6 g: yield 83.0%, colorless transparent viscous liquid).

[0208] <Synthesis Example 2: Synthesis of Poly-[2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl methacrylate]> [ka]

[0209] 2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl methacrylate (2.00 g, 6.84 mmol) obtained in Synthesis Example 1, AIBN (5.6 mg, 0.03 mmol), and NMP (8.0 g) were weighed into a 50 mL side-arm flask equipped with a stirrer. After purging with nitrogen three times, the mixture was reacted at 60°C for 24 hours with stirring. After completion of the reaction, NMP (13.3 g) and BCS (10.0 g) were added to obtain a polymer solution (Add-P1) for use in the present invention. The molecular weight of this polymer was number-average molecular weight (Mn): 16,200, weight-average molecular weight (Mw): 37,200.

[0210] <Synthesis Example 3: Synthesis of Poly-[2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl methacrylate]-co-methylmethacrylate> [ka]

[0211] 2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl methacrylate (2.00 g, 6.84 mmol) obtained in Synthesis Example 1, methylmethacrylate (0.68 g, 6.84 mmol), AIBN (11.2 mg, 0.06 mmol), and NMP (10.7 g) were weighed into a 50 mL side-arm flask equipped with a stirrer. After purging with nitrogen three times, the mixture was reacted at 60°C for 24 hours with stirring. After completion of the reaction, NMP (17.9 g) and BCS (13.4 g) were added to obtain a polymer solution (Add-P2) for use in the present invention. The molecular weight of this polymer was Mn: 13,800, Mw: 34,500.

[0212] <Synthesis Example 4: Synthesis of ISOBAM-derived photoradical-generating polymer> [ka]

[0213] DA-4 (6.43 g: 19.5 mmol), DMAP (21.5 mg: 0.17 mmol), and NMP (37.7 g) were weighed into a 200 mL side-arm flask equipped with a stirrer and dissolved by stirring. Then, ISOBAM-10 (Kuraray, 3.00 g) was added and the mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, NMP (62.9 g) and BCS (47.2 g) were added and stirred to obtain the polymer solution (Add-P3) used in the present invention. ISOBAM-10 is a copolymer of isobutylene and maleic anhydride.

[0214] <Synthesis Example 5 Photoalignment Agent> DA-2 (3.42 g, 14.0 mmol) and DA-3 (1.55 g, 6.0 mmol) were weighed into a 100 mL four-neck flask equipped with a mechanical stirrer and nitrogen inlet tube, and NMP (42.0 g) was added. After dissolving under a nitrogen atmosphere, TC-1 (4.21 g, 18.8 mmol) and NMP (10.0 g) were added while maintaining the temperature below 10 °C in an ice bath. The reaction was allowed to proceed at room temperature for 24 hours, yielding a polyamic acid solution (PAA-1) with a viscosity of approximately 710 mPa s and a solids concentration of 15% by weight. The molecular weight of this polyamic acid was Mn: 15,500, Mw: 41,800.

[0215] <Synthesis Example 6 Ref Radical-generating Photoalignment Agent> DA-1 (1.08 g, 10.0 mmol) and DA-4 (3.30 g, 10.0 mmol) were weighed into a 100 mL four-neck flask equipped with a mechanical stirrer and nitrogen inlet tube, and NMP (49.2 g) was added. After dissolving under a nitrogen atmosphere, TC-1 (4.30 g, 19.2 mmol) and NMP (10.0 g) were added while maintaining the temperature below 10 °C in an ice bath. The reaction was allowed to proceed at room temperature for 24 hours, yielding a polyamic acid solution (PAA-2) with a viscosity of approximately 280 mPa s and a solids concentration of 12% by weight. The molecular weight of this polyamic acid was Mn: 13,500, Mw: 39,200.

[0216] <Synthesis Example 7: Synthesis of Add-1 (1-phenylhexan-3-yl methacrylate)> [ka]

[0217] (1st step) Hydrocinnamaldehyde (25.0 g, 0.186 mol) and THF (300 mL) were weighed and dissolved in a 500 mL four-neck flask equipped with a stirrer. After cooling the solution to -78 °C in a dry ice-methanol bath, n-propylmagnesium bromide (1.5 mol / L THF solution, 186 mL, 0.279 mol) was added dropwise, ensuring the internal temperature did not exceed -70 °C. After the addition, the mixture was returned to room temperature and stirred for 18 hours. After confirming the completion of the reaction by HPLC, the reaction solution was cooled to 0 °C and quenched by adding 1 N aqueous hydrochloric acid (100 mL). Ethyl acetate (200 mL) was added to the reaction solution, which was then washed three times with pure water (100 mL) using a separatory funnel. After washing, the mixture was dehydrated over magnesium sulfate and the solvent was removed using a rotary evaporator to obtain a crude product. Further vacuum drying afforded Add-1a (30.0 g, 89% yield, colorless, transparent liquid).

[0218] (2nd process) Add-1a (30.0 g, 0.168 mol), TEA (25.5 g, 0.252 mol), and THF (300 mL) were weighed and dissolved in a 500 mL four-neck flask equipped with a stirrer. After cooling the solution to 0 °C in an ice bath, methacryloyl chloride (21.1 g, 0.201 mol) was gently added dropwise while maintaining the internal temperature below 5 °C. The mixture was then returned to room temperature and stirred for 18 hours. After confirming the completion of the reaction by HPLC, ethyl acetate (200 mL) was added to the reaction solution, which was then washed three times with 10% aqueous potassium carbonate (100 mL) and three times with purified water (100 mL) using a separatory funnel. After washing, the mixture was dehydrated over magnesium sulfate and the solvent was removed using a rotary evaporator to obtain a crude product. Purification was performed by silica gel column chromatography (developing solvent: n-hexane / ethyl acetate = 9 / 1 (volume ratio)), and Add-1 (35.6 g: yield 86%, colorless transparent liquid) was obtained by distilling off the solvent and drying in vacuo. 1 The product was confirmed to be the target product by H-NMR measurement. BHT (0.01 mol %) was added as a polymerization inhibitor. 1H-NMR(500MHz) in DMSO-d6: 7.28-7.15(5H), 6.02(1H), 5.64(1H), 4.90-4.88(1H), 2.62-2.55(2H), 1 .90-1.85(2H+3H), 1.59-1.54(2H), 1.30-1.28(2H), 0.88-0.86(3H)[ppm]

[0219] <<Preparation of liquid crystal alignment agent>> <Preparation Example 1: Preparation of Liquid Crystal Alignment Agent AL-1> 20.0 g of the polyamic acid solution (PAA-1) obtained in Synthesis Example 5 above was weighed into a 50 mL Erlenmeyer flask equipped with a stirrer, and NMP (15.0 g) and BCS (15.0 g) were added thereto. The mixture was stirred at room temperature for 1 hour to obtain a liquid crystal alignment agent (AL-1).

[0220] Preparation Example 2: Preparation of Photoradical-Generating Film-Forming Composition AL-2 20.0 g of the polyamic acid solution (PAA-2) obtained in Synthesis Example 6 above was weighed out and placed in a 50 mL Erlenmeyer flask equipped with a stirrer, and NMP (8.0 g) and BCS (12.0 g) were added thereto. The mixture was stirred at room temperature for 1 hour to obtain a photoradical-generating film-forming composition (AL-2).

[0221] Example 1 Preparation of Photoradical-Generating Film-Forming Composition AL-3 In a 50 mL Erlenmeyer flask equipped with a stirrer, 19.0 g of the liquid crystal aligning agent (AL-1) obtained in Preparation Example 1 above was weighed out, and Add-P1 (1.0 g) was added. The mixture was stirred at room temperature for 1 hour to obtain a photoradical-generating film-forming composition (AL-3) used in the present invention.

[0222] Example 2: Preparation of Photoradical-Generating Film-Forming Composition AL-4 In a 50 mL Erlenmeyer flask equipped with a stirrer, 19.9 g of the liquid crystal aligning agent (AL-1) obtained in Preparation Example 1 above was weighed out, and Add-P1 (0.1 g) was added. The mixture was stirred at room temperature for 1 hour to obtain a photoradical-generating film-forming composition (AL-4) used in the present invention.

[0223] Example 3: Preparation of Photoradical-Generating Film-Forming Composition AL-5 In a 50 mL Erlenmeyer flask equipped with a stirrer, 19.0 g of the liquid crystal aligning agent (AL-1) obtained in Preparation Example 1 above was weighed out, Add-P2 (1.0 g) was added, and the mixture was stirred at room temperature for 1 hour to obtain a photoradical-generating film-forming composition (AL-5) used in the present invention.

[0224] Example 4 Preparation of Photoradical-Generating Film-Forming Composition AL-6 In a 50 mL Erlenmeyer flask equipped with a stirrer, 19.0 g of the liquid crystal aligning agent (AL-1) obtained in Preparation Example 1 above was weighed out, and Add-P2 (0.1 g) was added. The mixture was stirred at room temperature for 1 hour to obtain a photoradical-generating film-forming composition (AL-6) used in the present invention.

[0225] Example 5 Preparation of Photoradical-Generating Film-Forming Composition AL-7 In a 50 mL Erlenmeyer flask equipped with a stirrer, 19.0 g of the liquid crystal aligning agent (AL-1) obtained in Preparation Example 1 above was weighed out, and Add-P3 (1.0 g) was added. The mixture was stirred at room temperature for 1 hour to obtain a photoradical-generating film-forming composition (AL-7) used in the present invention.

[0226] Example 6: Preparation of Photoradical-Generating Film-Forming Composition AL-8 Into a 50 mL Erlenmeyer flask equipped with a stirrer, 19.9 g of the liquid crystal aligning agent (AL-1) obtained in Preparation Example 1 above was weighed out, and Add-P3 (0.1 g) was added. The mixture was stirred at room temperature for 1 hour to obtain a photoradical-generating film-forming composition (AL-8) used in the present invention.

[0227] Example 7 Preparation of Photoradical-Generating Film-Forming Composition AL-9 Into a 50 mL Erlenmeyer flask equipped with a stirrer, 19.0 g of SE-6414 (manufactured by Nissan Chemical Industries, Ltd., solid content: 6.0 mass%) was weighed out, and Add-P1 (1.0 g) was added. The mixture was stirred at room temperature for 1 hour to obtain the photoradical-generating film-forming composition (AL-9) used in the present invention.

[0228] Example 8 Preparation of Photoradical-Generating Film-Forming Composition AL-10 19.9 g of SE-6414 was weighed into a 50 mL Erlenmeyer flask equipped with a stirrer, and Add-P1 (0.1 g) was added. The mixture was stirred at room temperature for 1 hour to obtain the photoradical-generating film-forming composition (AL-10) used in the present invention.

[0229] Example 9 Preparation of Photoradical-Generating Film-Forming Composition AL-11 19.0 g of SE-6414 was weighed into a 50 mL Erlenmeyer flask equipped with a stirrer, and Add-P2 (1.0 g) was added. The mixture was stirred at room temperature for 1 hour to obtain the photoradical-generating film-forming composition (AL-11) used in the present invention.

[0230] Example 10: Preparation of Photoradical-Generating Film-Forming Composition AL-12 19.9 g of SE-6414 was weighed into a 50 mL Erlenmeyer flask equipped with a stirrer, and Add-P2 (0.1 g) was added. The mixture was stirred at room temperature for 1 hour to obtain the photoradical-generating film-forming composition (AL-12) used in the present invention.

[0231] Example 11 Preparation of Photoradical-Generating Film-Forming Composition AL-13 19.0 g of SE-6414 was weighed into a 50 mL Erlenmeyer flask equipped with a stirrer, and Add-P3 (1.0 g) was added. The mixture was stirred at room temperature for 1 hour to obtain the photoradical-generating film-forming composition (AL-13) used in the present invention.

[0232] Example 12 Preparation of Photoradical-Generating Film-Forming Composition AL-14 19.9 g of SE-6414 was weighed into a 50 mL Erlenmeyer flask equipped with a stirrer, and Add-P3 (0.1 g) was added. The mixture was stirred at room temperature for 1 hour to obtain the photoradical-generating film-forming composition (AL-14) used in the present invention.

[0233] Preparation Example 3: Preparation of Photoradical-Generating Film-Forming Composition AL-15 10.0 g of the liquid crystal aligning agent (AL-1) obtained in Preparation Example 1 above and 10.0 g of the photoradical-generating film-forming composition (AL-2) obtained in Preparation Example 2 above were weighed into a 50 mL Erlenmeyer flask equipped with a stirrer, and the mixture was stirred at room temperature for 1 hour to obtain a photoradical-generating film-forming composition (AL-15) for comparison.

[0234] Preparation Example 4: Preparation of Photoradical-Generating Film-Forming Composition AL-16 10.0 g of SE-6414 and 10.0 g of the photoradical-generating film-forming composition (AL-2) obtained in Preparation Example 2 above were weighed into a 50 mL Erlenmeyer flask equipped with a stirrer, and the mixture was stirred at room temperature for 1 hour to obtain a photoradical-generating film-forming composition (AL-16) for comparison.

[0235] <Creating liquid crystal display elements> A method for preparing a liquid crystal cell for evaluating the liquid crystal alignment and electro-optical response will be described below. First, a substrate with electrodes was prepared. The substrate was a non-alkali glass substrate measuring 30mm x 35mm and 0.7mm thick. On the substrate, ITO (Indium-Tin-Oxide) electrodes with a comb-shaped pattern were formed, with an electrode width of 3μm, an electrode spacing of 6μm, and an angle of 10° with respect to the long side of the substrate, forming the first and second pixels. Each pixel was approximately 5mm long and 5mm wide. Hereafter, this will be referred to as an IPS substrate. Next, the photoradical-generating film-forming compositions AL-2 to AL-16 obtained by the above method, the liquid crystal alignment agent AL-1, and the liquid crystal alignment agent SE-6414 (manufactured by Nissan Chemical Industries, Ltd.) for horizontal alignment were filtered through a 1.0 μm pore size filter and then applied to the prepared IPS substrate and a backside ITO substrate (hereinafter referred to as the counter substrate) with an ITO film formed on the backside and 3.0 μm-high columnar spacers by spin coating. The substrate was then dried on a hot plate at 80°C for 80 minutes and baked at 230°C for 20 minutes to obtain a 100 nm-thick coating film. The coating on the IPS substrate side was subjected to an alignment treatment in the direction along the comb-tooth electrode, while the coating on the counter substrate side was subjected to an alignment treatment in the direction perpendicular to the comb-tooth electrode. The alignment treatment for AL-2, AL-9 to AL-14, AL-16, and SE-6414 was performed using a rubbing method with a rubbing device manufactured by Iinuma Gauge Co., Ltd., a rubbing cloth (YA-20R) manufactured by Yoshikawa Kako Co., Ltd., a rubbing roller (diameter 10.0 cm), a stage feed speed of 30 mm / s, a roller rotation speed of 700 rpm, and a pressing pressure of 0.4 mm. The alignment treatment for AL-1, AL-2, AL-3 to AL-8, and AL-15 was performed using a UV exposure device manufactured by Ushio Inc., using linearly polarized UV light with an extinction ratio of approximately 26:1 at an irradiation dose of 300 mJ / cm2 based on a wavelength of 254 nm. 2 The alignment treatment was carried out by irradiating the film with polarized UV light so that the alignment film was aligned. The two substrates were then combined in the combinations shown in Tables 1 and 3 below so that their alignment directions were parallel, and the periphery was sealed except for the liquid crystal injection port to prepare empty cells with a cell gap of approximately 3.0 μm. A liquid crystal composition containing 2.0% by mass of additive Add-1 was injected into the empty cells at room temperature under vacuum, and in some display elements (Comparative Examples 1 and 6) an additive-free liquid crystal composition was also injected. The injection port was then sealed to produce liquid crystal cells with antiparallel alignment. The liquid crystal mixture used was MLC-3019 (manufactured by Merck).

[0236] The obtained liquid crystal cell constitutes an IPS mode liquid crystal display element. Thereafter, the obtained liquid crystal cell was heat-treated at 120 °C for 10 minutes, and UV (UV lamp: FLR40SUV32 / A-1) was irradiated for 30 minutes using a UV-FL irradiation device manufactured by Toshiba Lighting & Technology Corporation in a state where no voltage was applied to obtain a liquid crystal display element.

[0237] <Evaluation of Liquid Crystal Alignment> Using a polarizing microscope, the polarizing plates were set to cross Nicol, fixed in a state where the brightness of the liquid crystal cell was minimized, and then the liquid crystal cell was rotated by 1° from there, and the alignment state of the liquid crystal was observed. When no alignment defects such as unevenness or domains were observed or when they were very slight, it was defined as "good", and when clearly observed, it was defined as "bad" for evaluation. Also, a photodiode was attached to the same polarizing microscope, connected to an electrometer via a current-voltage conversion amplifier, and the voltage under the condition where the brightness was minimized under cross Nicol was monitored to measure the black brightness (mV: a.u.).

[0238] <Measurement of V-T Curve, Driving Threshold Voltage, Maximum Brightness Voltage, and Transmittance Evaluation> A white LED backlight and a luminance meter were set so that the optical axes were aligned, and a liquid crystal cell (liquid crystal display element) with a polarizing plate attached so that the brightness was minimized was set between them. A voltage was applied up to 8V at 1V intervals, and the brightness at each voltage was measured to measure the V-T curve. The value of the voltage (Vmax) at which the brightness became maximum was estimated from the obtained V-T curve. Also, through a liquid crystal cell without voltage application, assuming the transmission brightness at parallel Nicol was 100%, the maximum transmittance (Tmax) was estimated by comparing the maximum transmission brightness in the V-T curve.

[0239] <Measurement of Response Time (Ton, Toff)> Using the device used for the measurement of the above V-T curve, the luminance meter was connected to an oscilloscope, and the response speed (Ton) when a voltage that became the maximum brightness was applied and the response speed (Toff) when the voltage was returned to 0V were measured.

[0240] <Burn-in Evaluation> A square wave voltage (60Hz) that maximized brightness was applied to the first pixel region of each liquid crystal cell, while no voltage was applied to the second pixel region. The cells were then driven at 60°C for 168 hours for aging. Burn-in was evaluated by comparing the brightness of the first and second pixels after aging. The smaller the difference in brightness, the better.

[0241] Table 2 shows the evaluation results of the examples and comparative examples of the liquid crystal display elements produced by the photoalignment method.

[0242] [Table 1]

[0243] [Table 2]

[0244] Examples 13 to 18, Comparative Example 2, and Comparative Example 4 each used a photo-radical generating film on the IPS substrate and a photo-alignment film on the opposing substrate, Examples 19 to 24, Comparative Example 3, and Comparative Example 5 each used a photo-alignment film on the IPS substrate and a photo-radical generating film on the opposing substrate, and Comparative Example 1 used a photo-alignment film on both substrates. Comparing Comparative Example 4 and Comparative Example 5, there is a tendency for image sticking to be improved by using a photoradical-generating film on the opposing substrate, but all of the examples using a photoradical-generating film obtained using the radical-generating film-forming composition of the present invention showed good image sticking. The photoradical-generating film obtained using the radical-generating film-forming composition of the present invention exhibited lower black luminance than either of the comparative examples and significantly improved transmittance compared to the strong-anchoring liquid crystal display element of Comparative Example 1, demonstrating that favorable weak-anchoring IPS characteristics were achieved when the photoradical-generating film obtained using the radical-generating film-forming composition of the present invention was used. While a slight decrease (longer) in response time due to weaker anchoring was observed, this was within an acceptable range. The response time and image sticking were significantly improved compared to Comparative Examples 2 and 3, which used photoradical-generating films made of polyimide alone. Even compared to Comparative Examples 4 and 5, which used blends of polyimides, the photoradical-generating film obtained using the radical-generating film-forming composition of the present invention also demonstrated improvements in black luminance, response time, and image sticking. Furthermore, while blends of polyimides exhibited effects at a blend ratio (solid content ratio) of 1:1, the addition of a small amount (e.g., approximately 0.5% to 5% by mass) relative to the solid content was sufficient for non-polyimide polymers such as the radical-generating film-forming composition of the present invention to achieve satisfactory effects. This is thought to be because polymers used as alignment components in in-plane switching liquid crystal alignment agents, such as polyamic acid and polyimide, have poor compatibility with polymers with significantly different structures, making layer separation more likely to occur during film formation.It is speculated that the efficient distribution of photoradical generating groups on the film surface in a sea-island pattern has made it possible to induce weak anchoring alignment without impairing the liquid crystal alignment properties.

[0245] Table 4 shows the results of the liquid crystal display device fabricated by the rubbing method.

[0246] [Table 3]

[0247] [Table 4]

[0248] Examples 25 to 30, Comparative Example 7, and Comparative Example 9 each used a photoradical generating film on the IPS substrate and a rubbed alignment film on the opposing substrate; Examples 31 to 36, Comparative Example 8, and Comparative Example 10 each used a rubbed alignment film on the IPS substrate and a photoradical generating film on the opposing substrate; and Comparative Example 6 used rubbed alignment films on both substrates. The same results were obtained with the liquid crystal display element fabricated by rubbing as with the liquid crystal display element fabricated by photoalignment. Furthermore, alignment components with side chains that induce radical polymerization are generally unsuitable for horizontal alignment films, making it difficult to achieve good liquid crystal alignment. However, the technology of the present invention does not directly introduce organic groups that induce radical polymerization into the alignment component, making it possible to achieve weak anchoring while maintaining good liquid crystal alignment. For the reasons mentioned above, it is possible to leave a region with a moderately strong anchoring energy state, which is thought to have improved the response speed (Toff). This study demonstrated that it is possible to produce the photoradical generating film required for weak anchoring IPS production simply by adding a small amount of a non-polyimide compound with a photoradical generating site to a conventional liquid crystal alignment film, and that the same effect can be obtained for both liquid crystal alignment films for rubbing and for photoalignment, indicating that good weak anchoring properties can be obtained regardless of the composition of the liquid crystal alignment film. [Industrial Applicability]

[0249] According to the present invention, it is possible to provide an in-plane switching liquid crystal display element that can be easily manufactured, can simultaneously achieve a low driving voltage and a fast response speed when the voltage is off, can display a good black image, and can effectively suppress image sticking, and can also provide a liquid crystal display element with good reliability. Therefore, the liquid crystal display element obtained by the method of the present invention is useful as an in-plane switching liquid crystal display element. [Explanation of symbols]

[0250] 1. In-plane switching liquid crystal display element 2. Interdigital electrode substrate 2a Base material 2b Linear electrode 2c Liquid crystal alignment film 2d base material 2e surface electrode 2f insulating film 2g linear electrode 2h Liquid crystal alignment film 3 LCD 4 Opposing substrate 4a Liquid crystal alignment film 4b Base material L electric field lines

Claims

1. Component (A): a polymer used as an alignment component of a liquid crystal alignment agent for in-plane switching drive, and Component (B): a polymer containing a group represented by the following formula (1) and having a structural unit derived from a monomer having a polymerizable carbon-carbon unsaturated bond: A radical-generating film-forming composition comprising: 【Chemical 1】 (In formula (1), * represents a binding site, R １ is a single bond, -CH ２ -, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ２ O-, -N(CH ３ )-,-CON(CH ３ ) - or -N(CH ３ )CO-. R ２ represents a single bond or an unsubstituted or fluorine atom-substituted alkylene group having 1 to 20 carbon atoms, and any —CH ２ -or-CF ２ One or more - may be independently replaced by a group selected from -CH=CH-, an optionally substituted divalent carbocyclic ring, and an optionally substituted divalent heterocyclic ring, and any -CH of the alkylene group may be further replaced by a group selected from -CH=CH-, an optionally substituted divalent carbocyclic ring, and an optionally substituted divalent heterocyclic ring. ２ -or-CF ２ One or more - may be replaced with at least one of the following groups, i.e., -O-, -COO-, -OCO-, -NHCO-, -CONH-, or -NH-, provided that these groups are not adjacent to each other. R ３ represents an organic group that induces radical polymerization, represented by the following formula [Y]. 【Chemistry 2】 (In formula [Y], * represents a bonding site; Ar represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene, and biphenylylene, which may have an organic group and / or a halogen atom as a substituent; R 9 and R 10 each independently represent an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, and when R 9 and R 10 are alkyl groups, they may be bonded to each other at their terminals to form a ring structure; and Q represents any of the following structures: 【Chemistry 3】 (In the formula, R 11 represents —CH 2 —, —NR—, —O—, or —S—, each R independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and * indicates a bonding site). S 3 represents a single bond, —O—, —NR— (wherein R represents a hydrogen atom or an alkyl group having 1 to 14 carbon atoms), or —S—.

2. 2. The radical-generating film-forming composition according to claim 1, wherein the polymer as component (A) is a polyimide precursor or a polyimide.

3. 3. The radical-generating film-forming composition according to claim 1, wherein the polymer as component (A) does not contain an organic group that induces radical polymerization.

4. 4. The radical-generating film-forming composition according to claim 1, wherein the content of said component (B) is 0.1 to 20% by mass relative to said component (A).

5. A radical-generating film obtained by using the radical-generating film-forming composition according to any one of claims 1 to 4.

6. A step of preparing a first substrate having the radical-generating film according to claim 5 and a second substrate which may have a radical-generating film; disposing the first substrate and the second substrate so that the radical generating film on the first substrate faces the second substrate; Filling a liquid crystal composition containing liquid crystal and a radical polymerizable compound between the first substrate and the second substrate; and a step of polymerizing the radical polymerizable compound while the liquid crystal composition is in contact with the radical-generating film; A method for manufacturing a liquid crystal display element comprising the steps of:

7. The method for producing a liquid crystal display element according to claim 6 , wherein the second substrate does not have a radical-generating film.

8. The method for manufacturing a liquid crystal display element according to claim 6, wherein the second substrate is a substrate coated with a liquid crystal alignment film having uniaxial alignment.

9. 9. The method for manufacturing a liquid crystal display element according to claim 8, wherein the liquid crystal alignment film having uniaxial alignment properties is a liquid crystal alignment film for horizontal alignment.

10. 10. The method for manufacturing a liquid crystal display element according to claim 6, wherein one of the first substrate and the second substrate has a comb-shaped electrode.

11. a first substrate, a second substrate disposed opposite to the first substrate, and a liquid crystal filled between the first substrate and the second substrate; A liquid crystal display element characterized by being produced by bringing a liquid crystal composition containing the liquid crystal and a radically polymerizable compound into contact with the radical-generating film of the first substrate having the radical-generating film described in claim 5, and polymerizing the radical-polymerizable compound in that state.

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