TWI866894B - Method of producing liquid crystal cell, and liquid crystal display element - Google Patents

Abstract

An object of the invention is to provide an industrial method for producing a zero plane anchoring film, a favorable liquid crystal display element that uses his film, and a method for producing the liquid crystal display element. The method for producing the zero plane anchoring film includes a step of applying sufficient energy to a liquid crystal composition containing a liquid crystal, a chiral dopant and a radical polymerizable compound to induce a polymerization reaction of the radical polymerizable compound, while the liquid crystal composition is in contact with a radical generating film. Furthermore, a method for creating a functional film includes a step of preparing a cell which has a liquid crystal compound containing a liquid crystal, a chiral dopant and a radical polymerizable compound between a first substrate that has a radical generating film and a second substrate that does not have a radical generating film, and a step of applying sufficient energy to the cell to induce a polymerization reaction of the radical polymerizable compound.

Description

Liquid crystal cell manufacturing method and liquid crystal display element

The present invention relates to a manufacturing method using polymer stabilization technology that can manufacture zero-surface anchoring films at low cost and without complicated steps, and a liquid crystal display element and its manufacturing method that uses the manufacturing method to achieve lower voltage drive.

In recent years, liquid crystal display elements have been widely used in mobile phones, computers, and television displays. Liquid crystal display elements have the characteristics of being thin, light, and low in power consumption. In the future, they are expected to be applied to VR, ultra-high-precision displays, and other further contents. A variety of display modes have been proposed for liquid crystal displays, such as TN (Twisted Nematic), IPS (In-Plane Switching), and VA (Vertical Alignment). All modes use a film (liquid crystal alignment film) that induces the liquid crystal to the desired alignment state.

In particular, products with touch panels such as tablet PCs, smart phones, and smart TVs prefer to use IPS mode, which does not easily disturb the display even when touched. In recent years, in order to improve contrast and viewing angle characteristics, liquid crystal display elements using FFS (Fringe Field Switching) and non-contact technology using optical alignment have gradually been adopted.

However, compared to IPS, FFS has a higher manufacturing cost for the substrate, and the problem of display defects unique to the FFS mode called Vcom offset occurs. In addition, compared to the friction method, the size of the components that can be manufactured is increased, and the display characteristics are greatly improved, but there are problems in the principle of photo-alignment (if it is a decomposition type, there will be display defects caused by decomposition products, and if it is anisotropic type, there will be burns caused by insufficient alignment force, etc.). In order to solve these problems, LCD display component manufacturers and LCD alignment film manufacturers have made various efforts.

On the other hand, in recent years, some people have proposed an IPS mode that utilizes zero-surface anchoring. By using this method, it is reported that it is possible to achieve better contrast and be driven at a significantly lower voltage than the conventional IPS mode (see patent document 1).

Specifically, a method of manufacturing an IPS mode liquid crystal display element is to use a liquid crystal alignment film with strong anchoring energy on one side of the substrate, and to perform a treatment on the substrate side with electrodes that generate a transverse electric field so that the alignment constraint force of the liquid crystal completely disappears.

In recent years, some people have used thick polymer brushes to create a zero-surface state and proposed a technology proposal for zero-surface anchoring of the IPS mode (reference document 2). This technology has achieved a significant improvement in contrast ratio and a significant reduction in driving voltage.

[Prior Art Literature]

[Patent Literature]

[Patent document 1] Japanese Patent No. 4053530

[Patent Document 2] Japanese Patent Publication No. 2013-231757

On the other hand, this technology has issues that will occur in principle. The first point is that in order to stably generate polymer brushes on the substrate, it must be done under very fine conditions, which is not practical if mass production is considered. The second point is that the alignment film is responsible for important functions such as suppressing imprinting, but when using polymer brushes, it is not easy to control the necessary electrical properties. The third point is that, for example, in terms of the driving principle, the response speed will become very slow when the voltage is off. By making the alignment constraint force zero, the resistance applied to the liquid crystal during driving is eliminated, and it can be expected that the threshold voltage will be greatly reduced, and the brightness will be improved by reducing the poor alignment area during driving. However, for the recovery of the liquid crystal, since the dynamic force of the liquid crystal during recovery depends on the elastic force of the liquid crystal, it is believed that the speed will be greatly reduced compared to when there is an alignment film.

If such technical issues can be solved, it will have significant cost benefits for panel manufacturers, and it is believed that it will also have benefits in terms of reducing battery consumption and improving image quality.

The present invention is to solve the above-mentioned problems, and aims to provide a manufacturing method that can manufacture a zero-surface anchor film using polymer stabilization technology, and a lateral electric field liquid crystal display element and its manufacturing method that can simultaneously achieve non-contact alignment, low drive voltage, and accelerated response speed when off at room temperature in a simple and low-cost method.

The inventors of this case have made great efforts to study and solve the above problems. As a result, they have found that the above problems can be solved and have completed the present invention with the following gist. That is, the present invention includes the following.

[1] A method for manufacturing a zero-surface anchor film, comprising the following steps: when a liquid crystal composition containing a liquid crystal, a chiral dopant and a free radical polymerizable compound is brought into contact with a free radical generating film, sufficient energy is provided to cause the free radical polymerizable compound to undergo a polymerization reaction.

[2] A method for manufacturing a zero-plane anchoring film as described in [1], wherein the free radical generating film of the first substrate is a free radical generating film that has been subjected to uniaxial alignment treatment.

[3] A method for manufacturing a zero-surface anchoring film as described in [1] or [2], wherein the step of applying energy is performed in the absence of an electric field.

[4] A method for manufacturing a zero-surface anchor film as described in any one of [1] to [3], wherein the free radical generating film is a film formed by fixing an organic group that induces free radical polymerization.

[5] A method for producing a zero-surface anchor film as described in any one of [1] to [3], wherein the free radical generating film is obtained by coating and curing a composition of a compound having a radical generating group and a polymer to form a film to fix the free radical in the film.

[6] A method for producing a zero-surface anchoring film as described in any one of [1] to [3], wherein the free radical generating film is composed of a polymer containing an organic group that induces free radical polymerization.

[7] A method for producing a zero-surface anchor film as described in [6], wherein the polymer containing an organic group that induces free radical polymerization is at least one polymer selected from polyimide precursors, polyimide, polyurea and polyamide obtained by using a diamine component containing a diamine containing an organic group that induces free radical polymerization.

[8] A method for producing a zero-surface anchor film as claimed in any one of items 4, 6 and 7 of the patent application, wherein the organic group inducing free radical polymerization is an organic group represented by the following structures [X-1] to [X-14], [W], [Y], [Z];

In formulas [X-1] to [X-14], * represents a bonding site with a portion other than a polymerizable unsaturated bond of a compound molecule, S ¹ and S ² each independently represent -O-, -NR-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, 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, and R ¹ and R ² each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms;

In the formulas [W], [Y], and [Z], * represents a bonding site with a portion other than a polymerizable unsaturated bond of a compound molecule, Ar represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene, and biphenylene which may have an organic group and/or a halogen atom as a substituent, ^R9 and ^R10 each independently represent an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, and when ^R9 and ^R10 are alkyl groups, they may be bonded to each other at the ends to form a ring structure; Q represents any of the following structures;

In the formula, R ¹¹ represents -CH ₂ -, -NR-, -O-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, * represents a bonding site with a portion other than Q of the compound molecule; 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.

[9] The method for producing a zero-surface anchor film as described in [7], wherein the diamine containing an organic group that induces free radical polymerization is a diamine having a structure represented by the following general formula (6) or the following general formula (7);

In formula (6), R ⁶ represents 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 ⁷ represents a single bond, or an unsubstituted or fluorine-substituted alkylene group having 1 to 20 carbon atoms; any one or more of -CH ₂ - or -CF ₂ - in the alkylene group may be independently replaced by a group selected from -CH=CH-, a divalent carbon ring, and a divalent heterocyclic ring; further, any one of the following groups, i.e., -O-, -COO-, -OCO-, -NHCO-, -CONH-, or -NH- may be replaced by these groups provided that they are not adjacent to each other; R ⁸ represents a free radical polymerization reactive group selected from the following formulae;

In formulas [X-1] to [X-14], * represents a bonding site with a portion other than a radical polymerization-reactive group of a compound molecule, S ¹ and S ² each independently represent -O-, -NR-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, 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, and R ¹ and R ² each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms;

In formula (7), ^T1 and ^T2 are each independently -O-, -S-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, _-CH2O- , -N( _CH3 )-, -CON( _CH3 )-, or -N( _CH3 )CO-, S represents a single bond, or an unsubstituted or fluorine-substituted alkylene group having 1 to 20 carbon atoms, any _-CH2- or _-CF2- of the alkylene group -One or more of - may be independently replaced by a group selected from -CH=CH-, a divalent carbon ring, and a divalent heterocyclic ring. Furthermore, any of the following groups, i.e., -O-, -COO-, -OCO-, -NHCO-, -CONH-, or -NH-, may be replaced by these groups provided that they are not adjacent to each other. J is an organic group represented by the following formula:

In the formulas [W], [Y], and [Z], * represents a bonding site with ^T2 , Ar represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene, and biphenylene which may have an organic group and/or a halogen atom as a substituent, ^R9 and ^R10 each independently represent an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, and Q represents any of the following structures;

In the formula, R ¹¹ represents -CH ₂ -, -NR-, -O-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, * represents a bonding site with a portion other than Q of the compound molecule; 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.

[10] A method for producing a zero-surface anchor film as described in any one of [1] to [9], wherein at least one of the free radical polymerizable compounds is a compound having one polymerizable unsaturated bond in one molecule and being compatible with liquid crystal.

[11] The method for producing a zero-surface anchor film according to [10], wherein the polymerizable unsaturated bond of the free radical polymerizable compound is selected from the following structures:

In the formula, * represents the bonding site other than the polymerizable unsaturated bond of the compound molecule.

[12] A method for producing a zero-surface anchor film as described in any one of [1] to [11], wherein the liquid crystal composition containing a liquid crystal, a chiral dopant and a radical polymerizable compound contains a radical polymerizable compound whose Tg of a polymer obtained by polymerizing the radical polymerizable compound is below 100°C.

[13] A method for manufacturing a liquid crystal cell, using a method for manufacturing a zero-surface anchoring film as described in any one of [1] to [12], comprising the following steps: preparing a first substrate having a free radical generating film and a second substrate which may also have a free radical generating film; manufacturing a cell in such a manner that the free radical generating film on the first substrate faces the second substrate; and filling a liquid crystal composition containing a liquid crystal, a chiral dopant and a free radical polymerizable compound between the first substrate and the second substrate.

[14] A method for manufacturing a liquid crystal cell as described in [13], wherein the second substrate is a second substrate without a free radical generating film.

[15] A method for manufacturing a liquid crystal cell as described in [14], wherein the second substrate is coated with a liquid crystal alignment film having a uniaxial alignment property.

[16] A method for manufacturing a liquid crystal cell as described in [15], wherein the liquid crystal alignment film having uniaxial alignment is a liquid crystal alignment film for horizontal alignment.

[17] A method for manufacturing a liquid crystal cell as described in any one of [13] to [16], wherein the first substrate having a free radical generating film is a substrate having a comb-tooth electrode.

[18] A liquid crystal composition comprising a liquid crystal, a chiral dopant and a free radical polymerizable compound, wherein at least one of the free radical polymerizable compounds is a compound that is compatible with the liquid crystal and has one polymerizable unsaturated bond in one molecule, and the polymerizable unsaturated bond is selected from the following structures;

In the formula, * represents the bonding site other than the polymerizable unsaturated bond of the compound molecule.

[19] A method for manufacturing a liquid crystal display element, using a film having a zero-surface anchoring state obtained by any of the methods of [1] to [17].

[20] A liquid crystal display element obtained using the manufacturing method of a liquid crystal display element as described in [19].

[21] A liquid crystal display element as described in [20], wherein the first substrate or the second substrate has an electrode.

[22] The liquid crystal display element as in [20] or [21] is a low voltage driven transverse electric field liquid crystal display element.

According to the present invention, a zero-surface anchor film can be manufactured industrially with good yield. Using the method of the present invention, a liquid crystal display element similar to the zero-surface anchor IPS mode liquid crystal display element described in Patent Documents 1 and 2 can be manufactured simply with low-cost raw materials and existing manufacturing methods. In addition, the liquid crystal display element obtained by the manufacturing method of the present invention can provide a liquid crystal display element with excellent characteristics such as faster response speed of liquid crystal when Off compared to the known technology, low driving voltage, no bright spots, suppression of Vcom offset in IPS mode, and higher precision in FFS mode.

The present invention is a method for manufacturing a zero-surface anchor film, which is characterized by: in a state where a free radical generating film contacts a liquid crystal containing a specific polymerizable compound, the polymerizable compound is polymerized by UV or heat. More specifically, the method comprises the following steps: preparing a unit cell having a liquid crystal composition containing a liquid crystal, a chiral dopant and a free radical polymerizable compound between a first substrate having a free radical generating film and a second substrate which may also have a free radical generating film; and providing the unit cell with sufficient energy for the free radical polymerizable compound to undergo a polymerization reaction. Preferably, a method for manufacturing a liquid crystal cell comprises the following steps: preparing a first substrate having a free radical generating film and a second substrate having no free radical generating film; manufacturing a cell in a manner that the free radical generating film faces the second substrate; and filling a liquid crystal composition containing liquid crystal, chiral dopants and free radical polymerizable compounds between the first substrate and the second substrate. For example, in a method for manufacturing a low voltage driven IPS liquid crystal display element, the second substrate has no free radical generating film and is a substrate having a liquid crystal alignment film treated with uniaxial alignment, and the first substrate is a substrate having a comb electrode.

In the present invention, "zero-plane anchor film" refers to a film that has no alignment constraint force on the liquid crystal molecules in the in-plane direction, or even if it has, it is weaker than the intermolecular force between the liquid crystals, and this film alone cannot make the liquid crystal molecules uniaxially align in any direction. In addition, this zero-plane anchor film is not limited to a solid film, but also includes a liquid film covering the surface of a solid. Usually, in a liquid crystal display element, a film that constrains the alignment of liquid crystal molecules, that is, a liquid crystal alignment film, is used in pairs to align the liquid crystal, but this zero-plane anchor film and a liquid crystal alignment film can also be used in pairs to align the liquid crystal. The reason is that the alignment constraint force of the liquid crystal alignment film will be transmitted to the thickness direction of the liquid crystal layer through the intermolecular force between the liquid crystal molecules, resulting in the alignment of the liquid crystal molecules close to the zero-plane anchor film. Therefore, when the liquid crystal alignment film is used for horizontal alignment, the entire liquid crystal cell can be aligned horizontally. Horizontal alignment refers to the state in which the long axis of the liquid crystal molecules is roughly parallel to the surface of the liquid crystal alignment film. Even if there is a tilted alignment of about several degrees, it is also included in the scope of horizontal alignment.

[Free radical generating film forming composition]

The free radical generating film forming composition used to form the free radical generating film used in the present invention contains a polymer and a group that can generate free radicals. At this time, the composition can contain a polymer bonded with a group that can generate free radicals, or a composition of a compound having a group that can generate free radicals and a polymer that becomes a base resin. By applying such a composition and curing to form a film, a free radical generating film in which the group that can generate free radicals is fixed in the film can be obtained. The group that can generate free radicals is preferably an organic group that can induce free radical polymerization.

Such organic groups that induce free radical polymerization include organic groups represented by [X-1]~[X-14], [W], [Y], and [Z] in the following structures.

In formulas [X-1] to [X-14], * represents a bonding site with a portion other than a polymerizable unsaturated bond of a compound molecule, S ¹ and S ² each independently represent -O-, -NR-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, 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, and R ¹ and R ² each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms;

In formulas [W], [Y], and [Z], * represents a bonding site other than a polymerizable unsaturated bond with a compound molecule, Ar represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene, and biphenylene which may have an organic group and/or a halogen atom as a substituent, ^R9 and ^R10 each independently represent an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, and when ^R9 and ^R10 are alkyl groups, the terminals may also be bonded to each other to form a ring structure. Q represents any of the following structures.

In the formula, R ¹¹ represents -CH ₂ -, -NR-, -O-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and * represents a bonding site with a portion other than Q of the compound molecule.

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.

The polymer is preferably at least one polymer selected from the group consisting of polyimide precursors, polyimide, polyurea, polyamide, polyacrylate, polymethacrylate, etc.

In order to obtain the free radical generating film used in the present invention, when using the aforementioned polymer having an organic group that induces free radical polymerization, in order to obtain a polymer having a group that can generate free radicals, as far as the monomer components are concerned, it is preferred to use a monomer having a photoreactive side chain containing at least one selected from methacrylic acid, acrylic acid, vinyl, allyl, coumarin, styryl and cinnamyl groups, and a monomer having a side chain having a site that is decomposed by ultraviolet irradiation and generates free radicals. On the other hand, considering the problem that the monomers that generate free radicals will spontaneously polymerize and become unstable compounds, it is more ideal to use polymers derived from diamines with free radical generating sites from the perspective of ease of synthesis, and more preferably polyamides, polyamide esters, polyimide precursors, polyimides, polyureas, polyamides, etc.

Such diamines containing free radical generating sites are, for example, diamines having side chains that can generate free radicals and polymerize, such as the diamines represented by the following general formula (6) but not limited thereto.

In formula (6), R ⁶ represents 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 ⁷ represents a single bond, or an unsubstituted or fluorine-substituted alkylene group having 1 to 20 carbon atoms; any one or more of -CH ₂ - or -CF ₂ - in the alkylene group may be independently substituted with a group selected from -CH=CH-, a divalent carbon ring, and a divalent heterocyclic ring; and may be substituted with any of the following groups, i.e., -O-, -COO-, -OCO-, -NHCO-, -CONH-, or -NH-, provided that the groups are not adjacent to each other; R ⁸ , represents a free radical polymerization reactive group selected from the following formula:

In formulae [X-1] to [X-14], * represents a bonding site with a portion other than a radical polymerization-reactive group of a compound molecule, S ¹ and S ² each independently represent -O-, -NR-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, 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, and R ¹ and R ² each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.

In formula (6), the bonding positions of the two amino groups (-NH ₂ ) are not limited. Specifically, the bonding positions relative to the side chain are 2,3 position, 2,4 position, 2,5 position, 2,6 position, 3,4 position, 3,5 position on the benzene ring. Among them, considering the reactivity when synthesizing polyamide, 2,4 position, 2,5 position, or 3,5 position is preferred. If the ease of synthesizing diamine is also considered, 2,4 position or 3,5 position is more ideal.

As diamines having at least one photoreactive group selected from the group consisting of methacrylic acid, acrylic acid, vinyl, allyl, coumarin, styryl and cinnamyl, the following compounds can be specifically listed but are not limited thereto.

In the formula, ^J1 represents a bonding group selected from a single bond, -O-, -COO-, -NHCO-, or -NH-, and ^J2 represents a single bond, or an unsubstituted or fluorine-substituted alkylene group having 1 to 20 carbon atoms.

As for the diamine having a site as a side chain that decomposes and generates free radicals by ultraviolet irradiation, the diamine represented by the following general formula (7) can be listed, but it is not limited to this.

In formula (7), ^T1 and ^T2 are each independently a single bond, -O-, -S-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH2O-, -N( _CH3 )-, -CON( _CH3 )-, or -N( _CH3 )CO-; S is _a single bond, or an unsubstituted or fluorine-substituted alkylene group having 1 to 20 carbon atoms; any one or more of _-CH2- or _-CF2- in the alkylene group may be independently substituted with a group selected from -CH=CH-, a divalent carbon ring, and a divalent heterocyclic ring; further, it may be substituted with any of the following groups, i.e., -O-, -COO-, -OCO-, -NHCO-, -CONH-, or -NH-, provided that the groups are not adjacent to each other; and J is an organic group represented by the following formula,

In the formulas [W], [Y], and [Z], * represents a bonding site with ^T2 , Ar represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene, and biphenylene which may have an organic group and/or a halogen atom as a substituent, ^R9 and ^R10 each independently represent an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, and Q represents any of the following structures.

In the formula, R ¹¹ represents -CH ₂ -, -NR-, -O-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and * represents a bonding site with a portion other than Q of the compound molecule.

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.

The bonding positions of the two amino groups (-NH ₂ ) in the above formula (7) are not limited. Specifically, the bonding groups relative to the side chains are 2,3 positions, 2,4 positions, 2,5 positions, 2,6 positions, 3,4 positions, and 3,5 positions on the benzene ring. Among them, if the reactivity during the synthesis of polyamide is considered, the 2,4 positions, 2,5 positions, or 3,5 positions are preferred. If the ease of synthesizing diamine is also considered, the 2,4 positions or 3,5 positions are more ideal.

In particular, considering the ease of synthesis, high versatility, characteristics, etc., the structure represented by the following formula is the most ideal but is not limited to this.

In the formula, n is an integer between 2 and 8.

The above diamines can be used alone or in combination of two or more, depending on the liquid crystal orientation when making a free radical generation film, the sensitivity in the polymerization reaction, the voltage holding characteristics, the accumulated charge and other characteristics.

Such a diamine having a free radical polymerization site is preferably used in an amount of 5 to 50 mol% of the total diamine component used in the synthesis of the polymer contained in the free radical film-forming composition, more preferably 10 to 40 mol%, and even more preferably 15 to 30 mol%.

Furthermore, when the polymer used in the free radical generating film of the present invention is obtained from diamine, other diamines other than the diamine having a free radical generating site may be used as diamine components as long as the effect of the present invention is not impeded. Specifically, for example, p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diaminobiphenyl, 3,3'-diaminodiphenylamine, 2,4'-diaminodiphenylamine, 2,5'-diaminodiphenylamine, 2,6'-diaminodiphenylamine, 2,5'-diaminodiphenylamine, 2,4 ... -dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-biphenyl, 3,3'-trifluoromethyl-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, 4 ,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminodiphenylmethane, 2,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonyldiphenylamine, 3,3'-sulfonyldiphenylamine, bis(4-aminodiphenylamine) phenyl) silane, bis(3-aminophenyl) silane, dimethyl-bis(4-aminophenyl) silane, dimethyl-bis(3-aminophenyl) silane, 4,4'-diaminodiphenylamine, 3,3'-diaminodiphenylamine, 4,4'-diaminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl(4,4'-diaminodiphenyl)amine, N-methyl(3,3'- diaminodiphenyl)amine, N-methyl(3,4'-diaminodiphenyl)amine, N-methyl(2,2'-diaminodiphenyl)amine, N-methyl(2,3'-diaminodiphenyl)amine, 4,4'-diaminodiphenyl phenone, 3,3'-diaminodiphenyl phenone, 3,4'-diaminodiphenyl phenone, 1,4-diaminonaphthalene, 2,2'-diaminodiphenyl phenone, 2,3'-diaminodiphenyl phenone, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminodiphenyl phenone Aminonaphthalene, 1,8-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 2,8-diaminonaphthalene, 1,2-bis(4-aminophenyl)ethane, 1,2-bis(3-aminophenyl)ethane, 1,3-bis(4-aminophenyl)propane, 1,3-bis(3-aminophenyl)propane, 1,4-bis(4-aminophenyl)butane, 1,4-bis(3-aminophenyl)butane, bis(3,5-diethyl-4-aminophenyl) 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4'-[1,4-phenylenebis(methylene)]diphenylamine, 4,4'-[1,3-phenylenebis(methylene)]diphenylamine, 3,4'-[1,4-phenylenebis(methylene)]diphenylamine bis(methylene)] diphenylamine, 3,4'-[1,3-phenylenebis(methylene)] diphenylamine, 3,3'-[1,4-phenylenebis(methylene)] diphenylamine, 3,3'-[1,3-phenylenebis(methylene)] diphenylamine, 1,4-phenylenebis[(4-aminophenyl)methanone], 1,4-phenylenebis[(3-aminophenyl)methanone], 1,3-phenylenebis[(4-aminophenyl)methanone], 1,3-phenylenebis[(3-aminophenyl)methanone] 1,4-phenylenebis(4-aminobenzoate), 1,4-phenylenebis(3-aminobenzoate), 1,3-phenylenebis(4-aminobenzoate), 1,3-phenylenebis(3-aminobenzoate), bis(4-aminophenyl)terephthalate, bis(3-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate, N,N'-(1,4-phenylene)bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate, phenyl)bis(4-aminobenzamide), N,N’-(1,3-phenylene)bis(4-aminobenzamide), N,N’-(1,4-phenylene)bis(3-aminobenzamide), N,N’-(1,3-phenylene)bis(3-aminobenzamide), N,N’-bis(4-aminophenyl)-p-phenylenediamide, N,N’-bis(3-aminophenyl)-p-phenylenediamide, N,N’-bis(4-aminophenyl)-m-phenylenediamide, N,N '-Bis(3-aminophenyl)m-xylylenediamide, 9,10-bis(4-aminophenyl)anthracene, 4,4'-bis(4-aminophenoxy)diphenylsulfone, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-aminophenyl)hexafluoropropane, 2,2'-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis(3-amino-4-methylphenyl) 2,2'-bis(4-aminophenyl)propane, 2,2'-bis(3-aminophenyl)propane, 2,2'-bis(3-amino-4-methylphenyl)propane, 1,4-bis(4-aminophenyl)cyclohexane, 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid, bis(4-aminophenoxy)methane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(4-aminophenoxy)propane, 1,3-bis(4-aminophenoxy)propane (3-aminophenoxy) propane, 1,4-bis(4-aminophenoxy) butane, 1,4-bis(3-aminophenoxy) butane, 1,5-bis(4-aminophenoxy) pentane, 1,5-bis(3-aminophenoxy) pentane, 1,6-bis(4-aminophenoxy) hexane, 1,6-bis(3-aminophenoxy) hexane, 1,7-bis(4-aminophenoxy) heptane, 1,7-bis(3-aminophenoxy) heptane, 1,8-bis(4-aminophenoxy) 1,8-Bis(3-aminophenoxy)octane, 1,9-Bis(4-aminophenoxy)nonane, 1,9-Bis(3-aminophenoxy)nonane, 1,10-Bis(4-aminophenoxy)decane, 1,10-Bis(3-aminophenoxy)decane, 1,11-Bis(4-aminophenoxy)undecane, 1,11-Bis(3-aminophenoxy)undecane, 1,12-Bis(4-aminophenoxy)dodecane, 1,12-Bis(3-aminophenoxy) Aromatic diamines such as bis(4-aminocyclohexyl)methane and bis(4-amino-3-methylcyclohexyl)methane; alicyclic diamines such as 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane Aliphatic diamines; diamines with urea structure such as 1,3-bis[2-(p-aminophenyl)ethyl]urea, 1,3-bis[2-(p-aminophenyl)ethyl]-1-tert-butoxycarbonylurea; diamines with nitrogen-containing unsaturated heterocyclic structure such as N-p-aminophenyl-4-p-aminophenyl(tert-butoxycarbonyl)aminomethylpiperidine; diamines with N-Boc group such as N-tert-butoxycarbonyl-N-(2-(4-aminophenyl)ethyl)-N-(4-aminobenzyl)amine, etc.

The above-mentioned other diamines can be used alone or in combination of two or more, depending on the liquid crystal orientation when making a free radical generation film, the sensitivity in the polymerization reaction, the voltage holding characteristics, the accumulated charge and other characteristics.

When the polymer is polyamide, the tetracarboxylic dianhydride to be reacted with the diamine component is not particularly limited. Specifically, pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7-anthracenetetracarboxylic acid, 1,2,5,6-anthracenetetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2,3,3',4'-biphenyltetracarboxylic acid, bis(3,4-dicarboxyphenyl)ether, 3,3',4,4'-benzophenonetetracarboxylic acid, bis(3,4-dicarboxyphenyl)sulfone, bis(3,4-dicarboxyphenyl)methane, 2,2-bis(3,4-dicarboxyphenyl)propane, 1,1,1,3,3,3-hexafluoro-2,2-bis(3,4-dicarboxyphenyl)propane , bis(3,4-dicarboxyphenyl)dimethylsilane, bis(3,4-dicarboxyphenyl)diphenylsilane, 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis(3,4-dicarboxyphenyl)pyridine, 3,3',4,4'-diphenylsulfonatetetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid, 1,3-diphenyl-1,2,3,4-cyclobutanetetracarboxylic acid, oxydiphthalidetetracarboxylic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid tetracarboxylic acid, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cycloheptanetetracarboxylic acid, 2,3,4,5-tetrahydrofurantetracarboxylic acid, 3,4-dicarboxy-1-cyclohexylsuccinic acid, 2,3,5-tricarboxycyclopentylacetic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid, bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic acid, bicyclo[4,3,0]nonane-2,4,7,9-tetracarboxylic acid, bicyclo[4,4,0]decane-2,4,7,9-tetracarboxylic acid, bicyclo[4,4,0]decane-2,4,8,10-tetracarboxylic acid, tricyclo[6.3.0.0 <2,6>] undecane-3,5,9,11-tetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, 4-(2,5-dihydroxytetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic acid, 5-(2,5-dihydroxytetrahydrofuranyl)-3-methyl-3-cyclohexane-1,2-dicarboxylic acid, tetracyclo[6,2,1,1,0<2,7>] dodecane-4,5,9,10-tetracarboxylic acid, 3,5,6-tricarboxynorbornane-2:3,5:6 dicarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid and other tetracarboxylic acid dianhydrides.

Of course, tetracarboxylic dianhydride can be used alone or in combination of two or more depending on the liquid crystal orientation when making a free radical generation film, the sensitivity in the polymerization reaction, the voltage holding characteristics, the stored charge and other characteristics.

When the polymer is a polyamic acid ester, the structure of the tetracarboxylic acid dialkyl ester that reacts with the above-mentioned diamine component is not particularly limited, and specific examples thereof are as follows.

Specific examples of the aliphatic tetracarboxylic acid diester include 1,2,3,4-cyclobutane tetracarboxylic acid dialkyl ester, 1,2-dimethyl-1,2,3,4-cyclobutane tetracarboxylic acid dialkyl ester, 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic acid dialkyl ester, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutane tetracarboxylic acid dialkyl ester, 1,2,3,4 -cyclopentanetetracarboxylic acid dialkyl ester, 2,3,4,5-tetrahydrofurantetracarboxylic acid dialkyl ester, 1,2,4,5-cyclohexanetetracarboxylic acid dialkyl ester, 3,4-dicarboxy-1-cyclohexylsuccinic acid dialkyl ester, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid dialkyl ester, 1,2,3,4-butanetetracarboxylic acid dialkyl ester, bicyclo[3,3,0]octane -2,4,6,8-tetracarboxylic acid dialkyl ester, 3,3',4,4'-dicyclohexyltetracarboxylic acid dialkyl ester, 2,3,5-tricarboxycyclopentylacetic acid dialkyl ester, cis-3,7-dibutylcyclooctane-1,5-diene-1,2,5,6-tetracarboxylic acid dialkyl ester, 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-dihydroxytetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid dialkyl ester, etc.

Aromatic tetracarboxylic acid dialkyl esters include pyromellitic acid dialkyl ester, 3,3',4,4'-biphenyltetracarboxylic acid dialkyl ester, 2,2',3,3'-biphenyltetracarboxylic acid dialkyl ester, 2,3,3',4-biphenyltetracarboxylic acid dialkyl ester, 3,3',4,4'-benzophenonetetracarboxylic acid dialkyl ester, 2,3,3',4'-benzophenonetetracarboxylic acid dialkyl ester, bis(3,4-dicarboxyphenyl)ether dialkyl ester, bis(3,4-dicarboxyphenyl)sulfonate dialkyl ester, 1,2,5,6-naphthalenetetracarboxylic acid dialkyl ester, 2,3,6,7-naphthalenetetracarboxylic acid dialkyl ester, etc.

In the synthesis of a polymer that is polyurea, the diisocyanate that reacts with the above-mentioned diamine component is not particularly limited and can be used according to availability, etc. The specific structure of the diisocyanate is shown below.

In the formula, R ²² and R ³³ represent an aliphatic hydrocarbon having 1 to 10 carbon atoms.

The aliphatic diisocyanates shown in K-1~K-5 have poor reactivity but have the advantage of better solvent solubility. The aromatic diisocyanates shown in K-6~K-7 are highly reactive and have the effect of improving heat resistance, but have the disadvantage of low solvent solubility. Considering the versatility and characteristics, K-1, K-7, K-8, K-9, and K-10 are particularly preferred. Considering the electrical characteristics, K-12 is more ideal. From the perspective of liquid crystal alignment, K-13 is particularly preferred. More than one diisocyanate can be used in combination, and it is better to use it according to the desired characteristics.

In addition, a portion of the diisocyanate can be substituted with the tetracarboxylic dianhydride described above, and can be used in the form of a copolymer of polyamide and polyurea, or can be used in the form of a copolymer of polyimide and polyurea by chemical imidization.

In the synthesis of the polymer being polyamide, the structure of the dicarboxylic acid to be reacted is not particularly limited, and specific examples are listed below. Specific examples of 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.

Examples of 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-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, Carboxylic acid, 1,3-cyclohexane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, 1,4-(2-norbornene) dicarboxylic acid, 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-dihydroxy-1,4-bicyclo[2.2.2]octane dicarboxylic acid, 1,3-adamantanedicarboxylic acid, 4,8-dihydroxy-1,3-adamantanedicarboxylic acid, 2,6-spiro[3.3]heptane dicarboxylic acid, 1,3-adamantanedicarboxylic acid, camphoric acid, etc.

Aromatic dicarboxylic acids include 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, 1,4-anthraquinonedicarboxylic acid, 2,5 -biphenyl dicarboxylic acid, 4,4'-biphenyl dicarboxylic acid, 1,5-diphenyl dicarboxylic acid, 4,4"-terphenyl dicarboxylic acid, 4,4'-diphenyl methane dicarboxylic acid, 4,4'-diphenyl ethane dicarboxylic acid, 4,4'-diphenyl propane dicarboxylic acid, 4,4'-diphenyl hexafluoropropane dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-bibenzyl dicarboxylic acid, 4,4'-stilbene dicarboxylic acid, 4,4 dicarboxylic acids such as '-ethylbenzene dibenzoic acid, 4,4'-carbonyl dibenzoic acid, 4,4'-sulfonyl dibenzoic acid, 4,4'-dithiodibenzoic acid, p-phenylenedicarboxylic acid, 3,3'-p-phenylenedicarboxylic acid, 4-carboxycinnamic acid, p-phenylenedicarboxylic 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, (isopropylenedi-p-phenylenedioxy)dibutyric acid, and bis(p-carboxyphenyl)dimethylsilane.

二唑-3,4-二羧酸、2,3-吡啶二羧酸、2,4-吡啶二羧酸、2,5-吡啶二羧酸、2,6-吡啶二羧酸、3,4-吡啶二羧酸、3,5-吡啶二羧酸等。 Examples of heterocyclic dicarboxylic acids 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, 3,5-pyridinedicarboxylic acid, and the like.

The above-mentioned various dicarboxylic acids may also be acylated dihalides or anhydride structures. If the dicarboxylic acids are dicarboxylic acids that can give a linear structure to a polyamide, they are more ideal in maintaining the orientation of liquid crystal molecules. Among them, terephthalic acid, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-diphenylethanedicarboxylic acid, 4,4'-diphenylpropanedicarboxylic acid, 4,4'-diphenylhexafluoropropanedicarboxylic acid, 2,2-bis(phenyl)propanedicarboxylic acid, 4,4-terphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,5-pyridinedicarboxylic acid or the acylated dihalides are more ideal. The compounds may also have isomers, and may also be a mixture including them. Furthermore, two or more compounds may be used in combination. Furthermore, the dicarboxylic acids used in the present invention are not limited to the above-mentioned exemplified compounds.

When a diamine (also described as "diamine component") as a raw material is reacted with a component selected from tetracarboxylic dianhydride (also described as "tetracarboxylic dianhydride component"), tetracarboxylic diester, diisocyanate and dicarboxylic acid as a raw material to obtain polyamine, polyamine ester, polyurea and polyamide, a known synthesis method can be used. Generally, there is a method of reacting a diamine component with one or more components selected from tetracarboxylic dianhydride component, tetracarboxylic diester, diisocyanate and dicarboxylic acid in an organic solvent.

The reaction between the diamine component and the tetracarboxylic dianhydride component is easier to carry out in an organic solvent and does not produce by-products, which is advantageous from this point of view.

The organic solvent used in the above reaction is not particularly limited as long as it can dissolve the generated polymer. Furthermore, even if it is an organic solvent that does not dissolve the polymer, it can be mixed with the above solvent within the range that the generated polymer does not precipitate. In addition, the water in the organic solvent will hinder the polymerization reaction and further cause the generated polymer to hydrolyze, so it is better to use an organic solvent that has been dehydrated and dried.

烷、正己烷、正戊烷、正辛烷、二乙醚、環己酮、碳酸伸乙酯、丙烯碳酸酯、乳酸甲酯、乳酸乙酯、乙酸甲酯、乙酸乙酯、乙酸正丁酯、乙酸丙二醇單乙醚、丙酮酸甲酯、丙酮酸乙酯、3-甲氧基丙酸甲酯、3-乙氧基丙酸甲基乙酯、3-甲氧基丙酸乙酯、3-乙氧基丙酸、3-甲氧基丙酸、3-甲氧基丙酸丙酯、3-甲氧基丙酸丁酯、二甘二甲醚、4-羥基-4-甲基-2-戊酮、2-乙基-1-己醇等。該等有機溶劑可單獨使用也可混用。 Organic solvents, such as 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-dimethylpropaneamide, N-methylcaprolactam, dimethyl Sulfide, tetramethylurea, pyridine, dimethyl sulfide, hexamethyl sulfide, γ-butyrolactone, isopropyl alcohol, methoxymethylpentyl alcohol, dipentene, ethyl amyl ketone, methyl nonanone, methyl ethyl ketone, methyl isoamyl ketone, methyl isoacetone, methyl cellulose, ethyl cellulose, methyl cellulose acetate, butyl cellulose acetate, ethyl cellulose 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, diisobutyl ketone

The organic solvents include 1,2-dimethylformamide, ...

When the diamine component and the tetracarboxylic dianhydride component are reacted in an organic solvent, the following methods can be listed: stirring the solution obtained by dispersing or dissolving the diamine component in the organic solvent, directly adding the tetracarboxylic dianhydride component, or adding it after dispersing or dissolving it in the organic solvent, adding the diamine component to the solution obtained by dispersing or dissolving the tetracarboxylic dianhydride component in the organic solvent, and alternately adding the tetracarboxylic dianhydride component and the diamine component. Any of these methods can be used. In addition, when the diamine component or the tetracarboxylic dianhydride component is composed of a plurality of compounds, they can be reacted in a premixed state, or they can be reacted individually in sequence, or low molecular weight bodies that have been reacted individually can be mixed and reacted to produce a high molecular weight body.

The temperature at which the diamine component and the tetracarboxylic dianhydride component react can be selected at any temperature, for example: -20~100℃, preferably in the range of -5~80℃. In addition, the reaction can be carried out at any concentration, for example: relative to the reaction solution, the total amount of the diamine component and the tetracarboxylic dianhydride component is 1~50 mass%, preferably 5~30 mass%.

In the above polymerization reaction, the ratio of the total molar number of the tetracarboxylic dianhydride component to the total molar number of the diamine component can be selected at any value according to the molecular weight of the polyamide to be obtained. As in the usual polycondensation reaction, the closer this molar ratio is to 1.0, the greater the molecular weight of the generated polyamide. The ideal range is 0.8~1.2.

The method for synthesizing the polymer used in the present invention is not limited to the above method. When synthesizing polyamide, the above tetracarboxylic acid dianhydride can be replaced with tetracarboxylic acid derivatives such as tetracarboxylic acid dihalide of corresponding structure in the same way as the general method for synthesizing polyamide, and the corresponding polyamide can be obtained by reacting them in a known manner. In addition, when synthesizing polyurea, diamine can be reacted with diisocyanate. When manufacturing polyamide ester or polyamide, diamine can be reacted with a component selected from tetracarboxylic acid diester and dicarboxylic acid in the presence of a known condensing agent, or after being derived into an acylate by a known method, it can be reacted with diamine.

The following methods can be cited for making polyimide by imidization of the above-mentioned polyamine: thermal imidization by directly heating the solution of polyamine, and catalytic imidization by adding a catalyst to the solution of polyamine. In addition, the imidization rate of polyamine to polyimide is preferably 30% or more, and 30-99% is more preferable, from the viewpoint of making the voltage retention rate high. On the other hand, considering the whitening property, that is, the viewpoint of inhibiting the precipitation of polymer in the varnish, 70% or less is better. If both properties are considered, 40-80% is more ideal.

The temperature for thermal imidization of polyamine in solution is usually 100~400℃, preferably 120~250℃, and it is better to discharge the water generated by the imidization reaction to the outside of the system.

The catalytic imidization of polyamide can be carried out by adding an alkaline catalyst and an acid anhydride to a solution of polyamide, usually at -20 to 250°C, preferably at 0 to 180°C, and stirring. The amount of the alkaline catalyst is usually 0.5 to 30 mole times of the amide group, preferably 2 to 20 mole times, and the amount of the acid anhydride is usually 1 to 50 mole times of the amide group, preferably 3 to 30 mole times. Examples of the alkaline catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, etc., among which pyridine is more ideal because it has a moderate alkalinity for the reaction to proceed. Acid anhydrides include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, etc. Among them, if acetic anhydride is used, it is easy to purify after the reaction, so it is more ideal. The imidization rate obtained by catalytic imidization can be controlled by adjusting the amount of catalyst, reaction temperature, reaction time, etc.

When recovering the polymer produced from the reaction solution of the polymer, the reaction solution can be put into a poor solvent and precipitated. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, butyl cellulose, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, water, etc. The polymer put into the poor solvent and precipitated can be filtered and recovered, and then dried at room temperature or heated under normal pressure or reduced pressure. In addition, if the polymer recovered by precipitation is dissolved in an organic solvent again and reprecipitated and recovered, and this operation is repeated 2 to 10 times, the impurities in the polymer can be reduced. The bad solvents at this time include alcohols, ketones, hydrocarbons, etc. If more than 3 of the bad solvents are used, the refining efficiency will be better, so it is more ideal.

Furthermore, when the aforementioned free radical generating film is composed of a polymer containing an organic group that induces free radical polymerization, the free radical generating film forming composition used in the present invention may also contain other polymers other than the polymer containing an organic group that induces free radical polymerization. In this case, the content of other polymers in the total polymer components is preferably 5 to 95% by mass, and more preferably 30 to 70% by mass.

The molecular weight of the polymer contained in the free radical film forming composition is preferably 5,000~1,000,000, and more preferably 10,000~150,000, when considering the strength of the free radical film obtained by coating the free radical film, the workability during film formation, and the uniformity of the film, as measured by the GPC (Gel Permeation Chromatography) method.

When the free radical generating membrane used in the present invention is obtained by coating and curing a composition of a compound having a free radical generating group and a polymer to form a film and fix it in the film, the polymer is a polymer selected from the group consisting of a polyimide precursor produced according to the above-mentioned production method, and polyimide, polyurea, polyamide, polyacrylate, polymethacrylate, etc., and at least one polymer can be obtained by using a diamine having a free radical polymerization site as 0 mol% of the diamine component of the total diamine component used in the synthesis of the polymer contained in the free radical generating membrane forming composition. The compound having a free radical generating group added at this time can be listed as follows.

Compounds that generate free radicals by heat are compounds that generate free radicals by heating to a temperature above the decomposition temperature. Such free radical thermal polymerization initiators include, for example, ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), diacyl peroxides (acetyl peroxide, benzoyl peroxide, etc.), hydrogen peroxides (hydrogen peroxide, tert-butyl hydroperoxide, isopropylbenzene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, diisopropylbenzene peroxide, dilauryl peroxide, etc.) , peroxyketal (dibutyl peroxycyclohexane, etc.), alkyl perester (tert-butyl peroxyneodecanoate, trimethyl peroxyacetic acid-tert-butyl ester, tert-pentyl peroxy 2-ethylcyclohexane acid, etc.), persulfate (potassium persulfate, sodium persulfate, ammonium persulfate, etc.), azo compounds (azobisisobutyronitrile, and 2,2'-bis(2-hydroxyethyl)a zobisisobutyronitrile, etc.). Such free radical thermal polymerization initiators can be used alone or in combination of two or more.

啉代丙-1-酮、2-苄基-2-二甲胺基-1-(4-

啉代苯基)-丁酮-1,4-二甲胺基苯甲酸乙酯、4-二甲胺基苯甲酸異戊酯、4,4’-二(第三丁基過氧羰基)二苯酮、3,4,4’-三(第三丁基過氧羰基)二苯酮、2,4,6-三甲基苯甲醯基二苯基氧化膦、2-(4’-甲氧基苯乙烯基)-4,6-雙(三氯甲基)-s-三

、2-(3’,4’-二甲氧基苯乙烯基)-4,6-雙(三氯甲基)-s-三

、2-(2’,4’-二甲氧基苯乙烯基)-4,6-雙(三氯甲基)-s-三

、2-(2’-甲氧基苯乙烯基)-4,6-雙(三氯甲基)-s-三

、2-(4’-戊氧基苯乙烯基)-4,6-雙(三氯甲基)-s-三

、4-[對N,N-二(乙氧基羰基甲基)]-2,6-二(三氯甲基)-s-三

、1,3-雙(三氯甲基)-5-(2’-氯苯基)-s-三

、1,3-雙(三氯甲基)-5-(4’-甲氧基苯基)-s-三

、2-(對二甲胺基苯乙烯基)苯并

唑、2-(對二甲胺基苯乙烯基)苯并噻唑、2-巰基苯并噻唑、3,3’-羰基雙(7-二乙胺基香豆素)、2-(鄰氯苯基)-4,4’,5,5’-四苯基-1,2’-聯咪唑、2,2’-雙(2-氯苯基)-4,4’,5,5’-肆(4-乙氧基羰基苯基)-1,2’-聯咪唑、2,2’-雙(2,4-二氯苯基)-4,4’,5,5’-四苯基-1,2’-聯咪唑、2,2’雙(2,4-二溴苯基)-4,4’,5,5’-四苯基-1,2’-聯咪唑、2,2’-雙(2,4,6-三氯苯基)-4,4’,5,5’-四苯基-1,2’-聯咪唑、3-(2-甲基-2-二甲胺基丙醯基)咔唑、3,6-雙(2-甲基-2-

啉代丙醯基)-9-正十二基咔唑、1-羥基環己基苯酮、雙(5-2,4-環戊二烯-1-基)-雙(2,6-二氟-3-(1H-吡咯-1-基)-苯基)鈦、3,3’,4,4’-四(第三丁 基過氧羰基)二苯酮、3,3’,4,4’-四(第三己基過氧羰基)二苯酮、3,3’-二(甲氧基羰基)-4,4’-二(第三丁基過氧羰基)二苯酮、3,4’-二(甲氧基羰基)-4,3’-二(第三丁基過氧羰基)二苯酮、4,4’-二(甲氧基羰基)-3,3’-二(第三丁基過氧羰基)二苯酮、2-(3-甲基-3H-苯并噻唑-2-亞基)-1-萘-2-基-乙酮、或2-(3-甲基-1,3-苯并噻唑-2(3H)-亞基)-1-(2-苯甲醯基)乙酮等。該等化合物可單獨使用，也可混用2種以上。 The compound that generates free radicals by light is not particularly limited as long as it is a compound that initiates free radical polymerization by light. Examples of such free 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-hydroxycyclohexylphenone, isopropylphenyl ether, isobutylphenyl ether, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, camphorquinone, benzanthrone, 2-methyl-1-[4-(methylthio)phenyl]-2-

Linopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-

4-Dimethylaminobenzoic acid ethyl ester, 4-Dimethylaminobenzoic acid isopentyl ester, 4,4'-di(tert-butylperoxycarbonyl)benzophenone, 3,4,4'-tri(tert-butylperoxycarbonyl)benzophenone, 2,4,6-trimethylbenzyldiphenylphosphine oxide, 2-(4'-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triphenylphosphine oxide,

, 2-(3',4'-dimethoxyphenylvinyl)-4,6-bis(trichloromethyl)-s-tri

, 2-(2',4'-dimethoxyphenylvinyl)-4,6-bis(trichloromethyl)-s-tri

, 2-(2'-methoxyphenylvinyl)-4,6-bis(trichloromethyl)-s-tri

, 2-(4'-pentyloxyphenylvinyl)-4,6-bis(trichloromethyl)-s-tri

, 4-[p-N,N-bis(ethoxycarbonylmethyl)]-2,6-bis(trichloromethyl)-s-tri

, 1,3-bis(trichloromethyl)-5-(2'-chlorophenyl)-s-tri

, 1,3-bis(trichloromethyl)-5-(4'-methoxyphenyl)-s-tri

, 2-(p-dimethylaminophenylvinyl)benzo

azole, 2-(p-dimethylaminophenyl)benzothiazole, 2-phenylbenzothiazole, 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'-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)- 2,2'-Bis(2,4-dibromophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-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-

1-Hydroxycyclohexylphenyl 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'-bis(methoxycarbonyl)-4,4'-di(tert-butylperoxycarbonyl)benzophenone, 1-(2-butylperoxycarbonyl)benzophenone, 3,4'-bis(methoxycarbonyl)-4,3'-bis(tert-butylperoxycarbonyl)benzophenone, 4,4'-bis(methoxycarbonyl)-3,3'-bis(tert-butylperoxycarbonyl)benzophenone, 2-(3-methyl-3H-benzothiazol-2-ylidene)-1-naphth-2-yl-ethanone, or 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.

Furthermore, even when the aforementioned free radical generating film is composed of a polymer having an organic group that induces free radical polymerization, in order to promote free radical polymerization when energy is given, a compound having the above-mentioned free radical generating group may be contained.

The free radical film-forming composition may contain an organic solvent that dissolves or disperses the polymer component and, if necessary, other components other than the free radical generator. Such an organic solvent is not particularly limited, for example, the organic solvent exemplified in the synthesis of the above-mentioned polyamine. Among them, N-methyl-2-pyrrolidone, γ-butyrolactone, N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropaneamide, etc. are ideal from the perspective of solubility. In particular, N-methyl-2-pyrrolidone or N-ethyl-2-pyrrolidone is preferred, but a mixed solvent of two or more may also be used.

Furthermore, it would be ideal if a solvent that improves the uniformity and smoothness of the coating is mixed with an organic solvent that has high solubility for the components contained in the free radical film-forming composition and used.

Solvents that improve the uniformity and smoothness of the coating, such as isopropyl alcohol, methoxymethylpentyl alcohol, methyl cellulose, ethyl cellulose, butyl cellulose, methyl cellulose acetate, butyl cellulose acetate, ethyl cellulose acetate, butyl carbitol, ethyl carbitol, ethyl carbitol acetate, 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-tertiary 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, 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, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate Isobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, n-hexane, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol acetate monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, 3- Butyl methoxypropionate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy)propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate, 2-ethyl-1-hexanol, etc. These solvents can also be mixed. When using these solvents, it is preferably 5-80% by mass of the total solvent contained in the liquid crystal alignment agent, and more preferably 20-60% by mass.

The radical film-forming composition may also contain ingredients other than those mentioned above. Examples include: compounds that improve the uniformity of film thickness and surface smoothness when the radical film-forming composition is applied, compounds that improve the adhesion between the radical film-forming composition and the substrate, compounds that improve the film strength of the radical film-forming composition, etc.

As compounds that improve the uniformity of film thickness and surface smoothness, there are fluorine-based surfactants, silicone-based surfactants, non-ionic surfactants, etc. More specifically, there are EFTOP EF301, EF303, EF352 (produced by Tohkem Products), Megafac F171, F173, R-30 (produced by Dainippon Ink Co., Ltd.), Fluorad FC430, FC431 (produced by Sumitomo 3M Co., Ltd.), AsahiGuard AG710, surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (produced by Asahi Glass Co., Ltd.), etc. When using such surfactants, the usage ratio is preferably 0.01 to 2 parts by mass, and more preferably 0.01 to 1 part by mass, relative to 100 parts by mass of the total amount of polymers contained in the free radical film-forming composition.

Specific examples of compounds that improve the adhesion between the radical generating film-forming composition and the substrate include compounds containing functional silanes and compounds containing epoxy groups. For example: 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, 2-aminopropyl trimethoxysilane, 2-aminopropyl triethoxysilane, N-(2-aminoethyl)-3-aminopropyl trimethoxysilane, N-(2-aminoethyl)-3-aminopropyl methyl dimethoxysilane, 3-ureidopropyl trimethoxysilane, 3-ureidopropyl triethoxysilane, N-ethoxycarbonyl-3-aminopropyl trimethoxysilane, N-ethoxycarbonyl-3-aminopropyl Triethoxysilane, N-triethoxysilylpropyl triethylenetriamine, N-trimethoxysilylpropyl triethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazononyl acetate, 9-triethoxysilyl-3,6-diazononyl acetate, N-benzyl-3-aminopropyl trimethoxysilane, N-benzyl-3-aminopropyl triethoxysilane, N -phenyl-3-aminopropyl trimethoxysilane, N-phenyl-3-aminopropyl triethoxysilane, N-bis(oxyethyl)-3-aminopropyl trimethoxysilane, N-bis(oxyethyl)-3-aminopropyl triethoxysilane, 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, glycerol diglycidyl ether, 2, 2-Dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N,N,N’,N’-tetraglycidyl-m-xylene diamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N’,N’-tetraglycidyl-4,4’-diaminodiphenylmethane, 3-(N-allyl-N-glycidyl)aminopropyltrimethoxysilane, 3-(N,N-diglycidyl)aminopropyltrimethoxysilane, etc.

In order to further enhance the strength of the free radical film, phenol compounds such as 2,2'-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane and tetrakis(methoxymethyl)bisphenol may be added. When using such compounds, the amount is preferably 0.1 to 30 parts by mass, and more preferably 1 to 20 parts by mass, relative to 100 parts by mass of the total amount of the polymer contained in the free radical film forming composition.

Furthermore, in addition to the above, dielectrics and conductive substances may be added to the radical generating film forming composition to change the electrical properties such as the dielectric constant and conductivity of the radical generating film, without damaging the effect of the present invention.

[Free radical generation membrane]

The free radical generating film of the present invention can be obtained using the above-mentioned free radical generating film forming composition. For example, the free radical generating film forming composition used in the present invention can be applied to a substrate, dried, and calcined to obtain a cured film, which can be directly used as a free radical generating film. In addition, the cured film can be rubbed, polarized, or irradiated with light of a specific wavelength, or treated with ion beams, or UV can be irradiated on a liquid crystal display element filled with liquid crystal as an alignment film for PSA.

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

To give specific examples, transparent electrodes are formed on glass plates, polycarbonate, poly(meth)acrylate, polyether sulfone, polyarylate, polyurethane, polysulfone, polyether, polyether ketone, trimethylpentene, polyolefin, polyethylene terephthalate, (meth)acrylonitrile, triacetyl cellulose, diacetyl cellulose, cellulose acetate butyrate and other plastic plates.

The substrate can be used for IPS liquid crystal display elements, and electrode patterns such as standard IPS comb electrodes, PSA herringbone electrodes, and protrusion patterns such as MVA can also be used.

In addition, in high-performance devices such as TFT type devices, a device such as a transistor is formed between an electrode for driving liquid crystal and a substrate.

When manufacturing a transmissive liquid crystal display element, the above-mentioned substrate is generally used. However, when manufacturing a reflective liquid crystal display element, if it is a substrate with only one side, an opaque substrate such as a silicon wafer can also be used. In this case, the electrode formed on the substrate can also use a material such as aluminum that reflects light.

As a coating method for the free radical generating film forming composition, there are spin coating, printing, ink jet, inkjet, roller coating, etc. However, from the aspect of productivity, the transfer printing method is widely used in industry and can also be used ideally in the present invention.

The drying step after coating the free radical generating film forming composition is not necessarily necessary, but when the time from coating to calcination of each substrate is not fixed, or when calcination is not performed immediately after coating, it is better to include a drying step. This drying can be done as long as the solvent is removed to the extent that the coating shape will not be deformed due to substrate transportation, etc., and there is no special restriction on the drying method. For example, it can be dried on a hot plate at a temperature of 40℃~150℃, preferably 60℃~100℃, for 0.5~30 minutes, preferably 1~5 minutes.

The coating formed by coating the free radical film-forming composition in the above method can be calcined to form a hardened film. The calcination temperature can usually be any temperature from 100°C to 350°C, preferably 140°C to 300°C, more preferably 150°C to 230°C, and more preferably 160°C to 220°C. The calcination time can usually be any time from 5 minutes to 240 minutes. It is preferably 10 to 90 minutes, and more preferably 20 to 90 minutes. Heating can use commonly known methods, such as: hot plate, hot air circulation oven, IR oven, belt furnace, etc.

The thickness of this cured film can be selected as needed. It is preferably 5nm or more, and more preferably 10nm or more, which is ideal because the reliability of the liquid crystal display element is easy to obtain. In addition, the thickness of the cured film is preferably 300nm or less, and more preferably 150nm or less, because the power consumption of the liquid crystal display element will not become extremely large, which is ideal.

The first substrate having a free radical generating film can be obtained in the above manner, but the free radical generating film can be subjected to a uniaxial alignment treatment. The methods for performing the uniaxial alignment treatment include photo-alignment, oblique evaporation, friction, and uniaxial alignment treatment using a magnetic field.

When the orientation treatment is performed by rubbing in a single direction, for example, the substrate is moved in a manner that the rubbing cloth contacts the film while the rubbing roller wrapped with the rubbing cloth is rotated. In the case of the first substrate of the present invention in which the comb electrode has been formed, the direction is selected by utilizing the electrical properties of the liquid crystal. However, when using liquid crystal with positive dielectric anisotropy, the rubbing direction is preferably set to be roughly the same direction as the extension direction of the comb electrode.

The second substrate of the present invention is the same as the first substrate except that it does not have a free radical generating film. It is preferably a substrate having a liquid crystal alignment film known in the past.

<Liquid crystal cell>

The liquid crystal cell of the present invention is obtained by forming a free radical generating film on a substrate by the above method, and then arranging the substrate with the free radical generating film (first substrate) and the substrate with a known liquid crystal alignment film (second substrate) in a manner that the free radical generating film and the liquid crystal alignment film face each other, clamping a spacer and fixing it with a sealant, and injecting a liquid crystal composition containing liquid crystal, chiral dopant and free radical polymerizable compound to seal it. The size of the spacer used at this time is usually 1~30μm, preferably 2~10μm.

There is no particular limitation on the method of injecting a liquid crystal composition containing liquid crystal, chiral dopant and free radical polymerizable compound. Examples include a vacuum method in which a mixture containing liquid crystal and polymerizable compound is injected after the prepared liquid crystal cell is placed in a depressurized state, and a dripping method in which a mixture containing liquid crystal and polymerizable compound is dripped and then sealed.

<Liquid crystal composition containing liquid crystal, chiral dopant and free radical polymerizable compound>

When the liquid crystal display element of the present invention is manufactured, the polymerizable compound used together with the liquid crystal is not particularly limited as long as it is a free radical polymerizable compound, for example: a compound having one or more polymerizable unsaturated bonds in one molecule. Preferably, it is a compound having one polymerizable unsaturated bond in one molecule (hereinafter sometimes referred to as "a compound having a monofunctional polymerizable group", "a compound having a monofunctional polymerizable group", etc.). The polymerizable unsaturated bond is preferably a free radical polymerizable unsaturated bond, such as a vinyl bond.

At least one of the aforementioned free radical polymerizable compounds is preferably a compound that is compatible with liquid crystal and has one polymerizable unsaturated bond in one molecule. In other words, a compound having a monofunctional free radical polymerizable group is preferred.

Furthermore, the polymerizable group of the aforementioned free radical polymerizable compound is preferably a polymerizable group selected from the following structures.

In the formula, * represents the bonding site other than the polymerizable unsaturated bond of the compound molecule.

Furthermore, the aforementioned liquid crystal composition containing liquid crystal, chiral dopant and free radical polymerizable compound preferably contains a free radical polymerizable compound whose Tg of the polymer obtained by polymerizing the aforementioned free radical polymerizable compound is below 100°C.

Compounds having monofunctional free radical polymerizable groups have unsaturated bonds that can undergo free radical polymerization in the presence of organic free radicals, such as 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, hexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, benzyl acrylate, lauryl acrylate, and n-octyl acrylate; styrene, styrene derivatives (e.g., o-, m-, p-methoxystyrene, o-, m-, p-tert-butoxystyrene, o-, m-, p-chloroform styrene, etc.), vinyl esters (e.g., vinyl acetate, vinyl propionate, vinyl benzoate, vinyl acetate, etc.), vinyl ketones (e.g., vinyl methyl ketone, vinyl hexyl ketone, methyl isoacrylate, etc.), N-vinyl compounds (e.g., N-vinyl pyrrolidone, N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, etc.), (meth) acrylic acid derivatives (e.g., acrylonitrile, methacrylonitrile, acrylamide, isopropyl acrylamide, methacrylamide, etc.), halogenated vinyls (e.g., vinyl chloride, vinylidene chloride, tetrachloroethylene, hexachlorobutadiene, vinyl fluoride, etc.), etc., but not limited to these. These various free radical polymerizable monomers can be used alone or in combination of two or more. In addition, they are preferably compatible with liquid crystals.

The content of the free radical polymerizable compound in the liquid crystal composition is preferably 0.1% by mass or more, more preferably 1% by mass or more, preferably 50% by mass or less, and more preferably 20% by mass or less, relative to the total mass of the liquid crystal and the free radical polymerizable compound.

The polymer obtained by polymerizing the aforementioned free radical polymerizable compound preferably has a Tg below 100°C.

In addition, liquid crystal generally refers to a substance in a state that exhibits both solid and liquid properties. Representative liquid crystal phases include nematic liquid crystal and lamellar liquid crystal. There is no particular limitation on the liquid crystal that can be used in the present invention. For example, it is 4-pentyl-4'-cyanobiphenyl.

Chiral dopants refer to optically active compounds added in small amounts to nematic liquid crystals in order to obtain cholesterol liquid crystals. Chiral dopants do not necessarily have to exhibit liquid crystal properties, but they can also be liquid crystal properties. Generally speaking, chiral dopants produce intermolecular forces that cause nematic liquid crystal molecules to align at slight angles to each other.

The helical pitch of cholesterol liquid crystal can vary depending on the structure and amount of chiral dopants added.

Specific examples of chiral dopants include non-polymerizable chiral compounds such as R-811, S-811, R-1011, S-1011, R-2011, S-2011, R-3011, S-3011, R-4011, S-4011, R-5011, S-5011, or CB15 (Merck), standard chiral dopants such as WO98/00428, Sorbitols described in A1, hydrophenylenes described in GB2,328,207, chiral binaphthols described in WO02/94805A1, chiral binaphthol acetals described in WO02/34739A1, chiral TADDOLs described in WO02/06265A1, or chiral compounds with fluorinated crosslinking groups described in WO02/06196A1 or WO02/06195A1. Polymeric chiral compounds, for example: polymeric chiral material Paliocolor (registered trademark) LC756 (BASF), etc.

The amount of chiral dopant added must be adjusted to an appropriate amount to achieve a certain degree of twist angle and twist pitch, usually in the range of 0.001 mass% to 1 mass%.

Then, sufficient energy is introduced into the liquid crystal cell containing the mixture of the liquid crystal, chiral dopant, and free radical polymerizable compound (liquid crystal composition) to make the free radical polymerizable compound undergo polymerization reaction. This can be implemented by, for example, heating or UV irradiation, and the desired properties are exhibited by polymerizing the free radical polymerizable compound in situ. Among them, the use of UV can make the orientation patternable and can perform the polymerization reaction in a short time. From this point of view, UV irradiation is better.

In addition, heating can also be performed during UV irradiation. The heating temperature during UV irradiation should ideally be within the temperature range where the introduced liquid crystal exhibits liquid crystal properties, usually above 40°C. It is better to heat at a temperature that does not reach the temperature at which the liquid crystal changes to the isotropic phase.

Here, the wavelength of UV irradiation during UV irradiation should preferably be the optimal wavelength for the reaction quantum yield of the polymerizable compound being reacted. The UV irradiation dose is usually 0.01~30J/ ^cm2 , preferably below 10J/ ^cm2 . The less UV irradiation dose, the more it can suppress the damage to the components constituting the liquid crystal display and the decrease in reliability. It is also ideal to improve the manufacturing tact by reducing the UV irradiation time. It is also possible to irradiate for a long time with a wavelength range including 313nm.

Furthermore, when polymerization is performed by heating only without UV irradiation, it is better to perform the polymerization at a temperature that allows the polymerizable compound to react but does not reach the decomposition temperature of the liquid crystal. Specifically, for example: above 40°C and below 100°C.

When sufficient energy is given to the free radical polymerizable compound to undergo a polymerization reaction, it is preferred to be in a no-electric-field state where no voltage is applied.

<Liquid crystal display element>

The liquid crystal cells obtained in this way can be used to make liquid crystal display devices.

For example: In this liquid crystal cell, reflective electrodes, transparent electrodes, λ/4 plates, polarizing films, color filter layers, etc. can be set according to conventional methods as needed to produce a reflective liquid crystal display element.

In addition, a backlight, polarizing plate, λ/4 plate, transparent electrode, polarizing film, color filter layer, etc. can be set on the liquid crystal cell according to the conventional method as needed to make a transmissive liquid crystal display element.

[Implementation example]

The present invention is more specifically described by examples, but the present invention is not limited to these examples. The abbreviations of the compounds used in the polymerization of polymers and the preparation of film-forming compositions, and the methods for evaluating the properties are as follows.

NMP: N-methyl-2-pyrrolidone

GBL: gamma-butyl lactone

BCS: Butyl Cellulose

<Viscosity measurement>

For the polyamide solution, use the E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample volume of 1.1 mL and Cone Rotor TE-1 (1°34’, R24) to measure the viscosity at 25°C.

<Determination of imidization rate>

20 mg of polyimide powder was placed in an NMR sample tube (NMR standard sample tube φ5 manufactured by Kusano Scientific Co., Ltd.), 0.53 ml of deuterated dimethyl sulfoxide (DMSO-d6, 0.05 mass% TMS (tetramethylsilane) mixture) was added, and ultrasound was applied to completely dissolve it. The 500 MHz proton NMR of this solution was measured using a measuring device (manufactured by JEC Data Corporation, JNW-ECA500).

The imidization rate is determined by taking the proton from the structure that does not change before and after imidization as the reference proton, and using the peak accumulation value of this proton and the peak accumulation value of the proton from the NH of the amide group appearing around 9.5~10.0ppm, it is calculated according to the following formula.

Imidization rate (%) = (1-α‧x/y) × 100

In the formula, x is the peak accumulation value of the protons from the NH of the amide group, y is the peak accumulation value of the reference proton, and α is the ratio of the number of reference protons to one NH proton of the amide group in polyamide (amidation rate is 0%).

<Polymerization of polymers and preparation of free radical-generating film-forming compositions>

Synthesis Example 1

Polymerization of TC-1, TC-2(50)/DA-1(50), DA-2(50) polyimide

In a 100ml 4-necked flask equipped with a nitrogen inlet tube, air cooling tube, and mechanical stirrer, 1.62g of DA-1 (15.00mmol) and 3.96g of DA-2 (15.00mmol) were weighed, and 48.2g of NMP was added. Stirred in a nitrogen environment to completely dissolve. After confirming the dissolution, 3.75g of TC-2 (15.00mmol) was added, and the mixture was reacted at 60℃ for 3 hours in a nitrogen environment. Return to room temperature, add 2.71g of TC-1 (13.80mmol), and reacted at 40℃ for 12 hours in a nitrogen environment. Confirm the polymerization viscosity, and add TC-1 in a way that the polymerization viscosity becomes 1000mPa‧s to obtain a polymerization solution with a polyamide concentration of 20 mass%.

60 g of the polyamine solution obtained above was weighed into a 200 ml Erlenmeyer flask equipped with a magnetic stirrer, and 111.4 g of NMP was added to prepare a 7% by mass solution. 9.10 g (88.52 mmol) of acetic anhydride and 3.76 g (47.53 mmol) of pyridine were added while stirring. After stirring at room temperature for 30 minutes, the mixture was stirred at 55°C for 3 hours to react. After the reaction was completed, the solution was returned to room temperature, and the reaction solution was poured into 500 ml of methanol while stirring to precipitate a solid. The solid was recovered by filtration, and then added to 300 ml of methanol and stirred for 30 minutes to wash. This was repeated twice in total. The solid was recovered by filtration, air-dried, and then dried in a vacuum oven at 60°C to obtain polyimide (PI-1) with a number average molecular weight of 11,300, a weight average molecular weight of 32,900, and an imidization rate of 53%.

Synthesis Example 2

Polymerization of TC-1, TC-2(50)/DA-1(50), DA-3(50) polyimide

In a 100ml 4-necked flask equipped with a nitrogen inlet tube, air cooling tube, and mechanical stirrer, 1.62g of DA-1 (15.00mmol) and 4.96g of DA-3 (15.00mmol) were weighed, and 51.90g of NMP was added. Stirred and dissolved completely in a nitrogen environment. After confirming the dissolution, 3.75g of TC-2 (15.00mmol) was added, and reacted at 60℃ for 3 hours in a nitrogen environment. Return to room temperature, add 2.64g of TC-1 (13.5mmol), and reacted at 40℃ for 12 hours in a nitrogen environment. Confirm the polymerization viscosity, and add TC-1 in a way that the polymerization viscosity becomes 1000mPa‧s to obtain a polymerization solution with a polyamide concentration of 20 mass%.

60 g of the polyamine solution obtained above was weighed into a 200 ml Erlenmeyer flask equipped with a magnetic stirrer, and 111.4 g of NMP was added to prepare a 7 mass % solution. 8.38 g (81.4 mmol) of acetic anhydride and 3.62 g (45.8 mmol) of pyridine were added while stirring. After stirring at room temperature for 30 minutes, the mixture was stirred at 55°C for 3 hours to react. After the reaction was completed, the solution was returned to room temperature, and the reaction solution was poured into 500 ml of methanol while stirring to precipitate a solid. The solid was recovered by filtration, and then added to 300 ml of methanol and stirred for 30 minutes to wash twice. The solid was recovered by filtration, air-dried, and then dried in a vacuum oven at 60°C to obtain a polyimide (PI-2) with a number average molecular weight Mn of 13100, a weight average molecular weight Mw of 34000, and an imidization rate of 55%.

Synthesis Example 3

Polymerization of TC-1, TC-2(50)/DA-1(50), DA-4(50) polyimide

In a 100ml 4-necked flask equipped with a nitrogen inlet tube, air cooling tube, and mechanical stirrer, 1.62g of DA-1 (15.00mmol) and 5.65g of DA-4 (15.00mmol) were weighed, and 55.4g of NMP was added and stirred in a nitrogen environment to completely dissolve. After confirming the dissolution, 3.75g of TC-2 (15.00mmol) was added and reacted at 60℃ for 3 hours in a nitrogen environment. Return to room temperature, add 2.82g of TC-1 (14.40mmol), and react at 40℃ for 12 hours in a nitrogen environment. Confirm the polymerization viscosity, and add more TC-1 in a way that the polymerization viscosity becomes 1000mPa‧s to obtain a polymerization solution with a polyamide concentration of 20 mass%.

60 g of the polyamine solution obtained above was weighed into a 200 ml Erlenmeyer flask equipped with a magnetic stirrer, and 111.4 g of NMP was added to prepare a 7 mass % solution. 8.36 g (81.2 mmol) of acetic anhydride and 3.65 g (46.1 mmol) of pyridine were added while stirring. After stirring at room temperature for 30 minutes, the mixture was stirred at 55°C for 3 hours to react. After the reaction was completed, the solution was returned to room temperature, and the reaction solution was poured into 500 ml of methanol while stirring to precipitate a solid. The solid was recovered by filtration, and then added to 300 ml of methanol and stirred for 30 minutes for a total of 2 times. The solid was recovered by filtration, air-dried, and dried in a vacuum oven at 60°C to obtain a polyimide (PI-3) with a number average molecular weight Mn of 12900, a weight average molecular weight Mw of 31000, and an imidization rate of 51%.

Free radical film-forming composition: Preparation of AL1

2.0 g of the polyimide powder (PI-1) obtained in Synthesis Example 1 was weighed into a 50 ml conical flask equipped with a magnetic stirrer, and 18.0 g of NMP was added and stirred at 50°C to completely dissolve it. Then 6.7 g of NMP and 6.7 g of BCS were added and stirred for 3 hours to obtain the free radical film-forming composition of the present invention: AL1 (solid content: 6.0 mass%, NMP: 66 mass%, BCS: 30 mass%).

Free radical film-forming composition: Preparation of AL2

In a 50ml Erlenmeyer flask equipped with a magnetic stirrer, 2.0g of the polyimide powder (PI-2) obtained in Synthesis Example 2 was weighed, 18.0g of NMP was added, and stirred at 50°C to completely dissolve it. Then 6.7g of NMP and 6.7g of BCS were added, and further stirred for 3 hours to obtain the free radical film-forming composition of the present invention: AL2 (solid content: 6.0% by mass, NMP: 66% by mass, BCS: 30% by mass).

Preparation of non-free radical film-forming composition: AL3

In a 50ml Erlenmeyer flask equipped with a magnetic stirrer, 2.0g of the polyimide powder (PI-3) obtained in Synthesis Example 3 was weighed, 18.0g of NMP was added, and stirred at 50°C to completely dissolve it. Then 6.7g of NMP and 6.7g of BCS were added, and stirred for further 3 hours to obtain a non-free radical film-forming composition for comparison: AL3 (solid content: 6.0% by mass, NMP: 66% by mass, BCS: 30% by mass).

【Table 1】Table 1 Composition of polyimide

<Production of liquid crystal display elements>

Using the AL1~AL3 obtained above and the liquid crystal alignment agent SE-6414 (manufactured by Nissan Chemical Co., Ltd.) for horizontal alignment, a liquid crystal display element was manufactured with the composition shown in Table 3.

(1st substrate)

The first substrate (hereinafter also referred to as the IPS substrate) is an alkali-free glass substrate with a size of 30mm×35mm and a thickness of 0.7mm. An ITO (Indium-Tin-Oxide) electrode with a comb-shaped pattern with an electrode width of 10μm and an electrode spacing of 10μm is formed on the substrate, and pixels are formed. The size of each pixel is 10mm in length and about 5mm in width.

AL1~AL3 or SE-6414 were filtered with a 1.0μm filter, then applied to the electrode formation surface of the above IPS substrate by spin coating and dried on a hot plate at 80℃ for 1 minute. Then, AL1~AL3 were calcined at 150℃ for 20 minutes, and SE-6414 was calcined at 220℃ for 20 minutes to form a coating with a thickness of 100nm each.

When the friction treatment is "yes", the friction is performed so that the friction direction becomes parallel to the comb electrode. The friction is performed on the spun yarn cloth: YA-20R manufactured by Yoshikawa Chemical Industry, with a roller diameter of 120mm, a rotation speed of 300rpm, a moving speed of 50mm/sec, and a pushing amount of 0.4mm. However, the above rotation speed is set to 1000rpm for the film coated with SE-6414 only. After the friction treatment, ultrasonic irradiation is performed in pure water for 1 minute and drying is performed at 80℃ for 10 minutes.

(Second substrate)

The second substrate (also called the back ITO substrate) is an alkali-free glass substrate with a size of 30mm×35mm and a thickness of 0.7mm. An ITO film is formed on the back side (the surface facing the outside of the cell). In addition, a columnar spacer with a height of 4μm is formed on the surface (the surface facing the inside of the cell).

AL1, AL2 or SE-6414 was filtered with a 1.0μm filter, then applied to the electrode-forming surface of the above-mentioned IPS substrate by spin coating, and dried on a hot plate at 80°C for 1 minute. Then, AL1 and AL2 were calcined at 150°C for 20 minutes, and SE-6414 was calcined at 220°C for 20 minutes to obtain a film with a thickness of 100nm each, and then rubbed. The rubbing treatment was performed using a spun yarn cloth: YA-20R manufactured by Yoshikawa Chemical Industry, with a roller diameter of 120mm, a rotation speed of 1000rpm, a moving speed of 50mm/sec, and a pushing amount of 0.4mm. However, when the film of AL1 or AL2 was applied, the above rotation speed was set to 300rpm. After the friction treatment, the product was irradiated with ultrasound for 1 minute in pure water and dried at 80°C for 10 minutes.

(Production of liquid crystal cells)

Using the above two substrates (first substrate and second substrate) with liquid crystal alignment films, leaving the liquid crystal injection port and sealing the periphery, an empty cell with a cell gap of about 4μm is produced. At this time, if the first substrate has not been rubbed, the direction of the comb electrode of the first substrate and the rubbing direction of the second substrate are parallel. If the first substrate has been rubbed, the rubbing directions of the first substrate and the second substrate are reversely parallel.

In this empty cell, liquid crystal (MLC-3019 made by Merck with 10wt% HMA added) was vacuum injected at room temperature, and the injection port was sealed to obtain a liquid crystal cell. The obtained liquid crystal cell constitutes an IPS mode liquid crystal display element. The obtained liquid crystal cell was then heated at 120°C for 20 minutes.

When UV treatment is performed, a high-pressure mercury lamp is used to irradiate the liquid crystal cell with ultraviolet light through a bandpass filter with a wavelength of 313nm, so that the exposure amount becomes 1000mJ/ ^cm2 .

<Evaluation of liquid crystal alignment>

Use a polarizing plate installed in cross nicol to confirm the alignment of the liquid crystal cell. Those with no defects and alignment are rated as ○, those with slight alignment defects are rated as △, and those without alignment are rated as ×.

<Measurement of V-T curve and evaluation of driving threshold voltage and maximum brightness voltage>

The white LED backlight and brightness meter are installed in a way that the optical axis is aligned. The liquid crystal cell (liquid crystal display element) with a polarizing plate installed is placed between them in a way that the brightness is minimized. The voltage is applied at intervals of 1V up to 8V, and the brightness of the voltage is measured to implement the measurement of the V-T curve. The driving threshold voltage and the voltage value at which the brightness is maximized are estimated from the obtained V-T curve.

<Evaluation of the response speed of liquid crystal display>

Using the device used for measuring the V-T curve above, connect the brightness meter to the oscilloscope and measure the response speed (Ton) when the voltage that achieves maximum brightness is applied and the response speed (Toff) when the voltage is 0.

In the comparison of Cell-1 to Cell-20, which used a horizontal alignment film with a rubbing treatment on the back ITO substrate (second substrate), Cell-11, Cell-12, Cell-16, and Cell-17, which used a free radical generating film and were UV treated on the IPS substrate (first substrate), confirmed that the alignment of the liquid crystal was good and the driving threshold voltage and the maximum brightness voltage were reduced. In addition, it was confirmed that the Toff value increased in Cell-11 and Cell-12, which did not undergo a rubbing treatment on the free radical generating film, while the increase in the Toff value was greatly improved in Cell-16 and Cell-17, which underwent a rubbing treatment on the free radical generating film.

In addition to the above, for supplementary experiments, AL1 was produced using both the back ITO substrate (second substrate) and the IPS substrate (first substrate), and neither the first substrate nor the second substrate was subjected to rubbing treatment. This liquid crystal cell observed alignment defects and bright spots (flow alignment) along the flow direction of the liquid crystal injection before UV irradiation, but the flow alignment completely disappeared after UV irradiation, and microdomains (isomers (schlieren)) from the liquid crystal were confirmed. This suggests that when a liquid crystal containing a free radical generating film and a polymerizable compound is used together, the free radical generating film loses the liquid crystal alignment constraint by irradiating UV, and a zero-surface anchoring film is formed on the free radical generating film.

In the comparison of liquid crystal cells Cell-21 to Cell-24, Cell-21 and Cell-23 without UV irradiation showed uniaxial orientation in the rubbing direction, but Cell-22 and Cell-24 with UV irradiation became non-oriented and generated microdomains (isomeric bodies) of liquid crystal. This suggests that even if the free radical generating film is rubbed, a zero-plane anchoring film can be formed on the free radical generating film by irradiating UV.

However, if Cell-22 and Cell-24 are rotated and observed under orthogonal Nicols, slight changes in brightness will occur, indicating that this zero-plane anchoring film is not completely without alignment constraint force, but this constraint force is weaker than the intermolecular force between liquid crystals, and this constraint force alone will not cause the liquid crystal molecules to uniaxially align in any direction. It can be seen that the Toff value in Cell-16 and Cell-17 has been greatly improved, mainly due to the above-mentioned weak constraint force.

<Production of liquid crystal display elements>

Using the above-obtained AL1~AL3 and the liquid crystal alignment agent SE-6414 (manufactured by Nissan Chemical Co., Ltd.) for horizontal alignment, a liquid crystal display element was manufactured with the composition shown in Table 5.

(1st substrate)

The first substrate (hereinafter also referred to as the FFS substrate) is a glass substrate with a size of 30mm×35mm and a thickness of 0.7mm. On the substrate, as for the first layer, an IZO electrode constituting a counter electrode is formed on the entire surface. On the first layer of the IZO electrode, as for the second layer, a SiN (silicon nitride) film formed by the CVD method is formed. The film thickness of the second layer of the SiN film is 500nm, and it acts as an interlayer insulating film. On the second layer of the SiN film, as for the third layer, a comb-shaped pixel electrode formed by patterning the IZO film is arranged, and the size of the pixel is about 10mm in length and 10mm in width. At this time, the counter electrode of the first layer and the pixel electrode of the third layer are electrically insulated by the SiN film of the second layer.

In the comb-shaped electrode shape of the third layer, the width of the electrode in the short side direction is 3μm, and the distance between electrodes is 6μm.

AL1~AL3 or SE-6414 were filtered with a 1.0μm filter, then applied to the electrode formation surface of the above FFS substrate by spin coating and dried on a hot plate at 80℃ for 1 minute. Then, AL1~AL3 were calcined at 210℃ for 20 minutes, and SE-6414 was calcined at 220℃ for 20 minutes, forming a coating with a thickness of 100nm.

When the friction treatment is "yes", the friction is performed in a manner that the friction direction is crossed at an angle of 85° relative to the long side direction of the comb electrode. The friction is performed using a spun yarn cloth: YA-20R manufactured by Yoshikawa Chemical Industry, with a roller diameter of 120mm, a rotation speed of 300rpm, a moving speed of 50mm/sec, and a pushing amount of 0.4mm. However, the above rotation speed is set to 1000rpm only for the film coated with SE-6414. After the friction treatment, ultrasonic irradiation is performed in pure water for 1 minute and drying is performed at 80℃ for 10 minutes.

(Second substrate)

The second substrate (also called the back ITO substrate) is an alkali-free glass substrate with a size of 30mm×35mm and a thickness of 0.7mm. An ITO film is formed on the back side (the surface facing the outside of the cell). In addition, a columnar spacer with a height of 4μm is formed on the surface (the surface facing the inside of the cell).

The liquid crystal alignment agent was applied by using SE-6414, filtered with a 1.0μm filter, and then applied to the surface of the above-mentioned back ITO substrate by spin coating, and dried on a hot plate at 80℃ for 1 minute. Then, it was calcined at 220℃ for 20 minutes to obtain a film with a thickness of 100nm, and then rubbed. The rubbing treatment was performed using a spun cloth: YA-20R made by Yoshikawa Chemical Industry, with a roller diameter of 120mm, a rotation speed of 1000rpm, a moving speed of 50mm/sec, and a pushing amount of 0.4mm. However, when the AL1 or AL2 film was applied, the above rotation speed was set to 300rpm. After the friction treatment, the product was irradiated with ultrasound for 1 minute in pure water and dried at 80°C for 10 minutes.

(Production of liquid crystal cells)

Using the above two substrates (first substrate and second substrate) with liquid crystal alignment films, leaving the liquid crystal injection port and sealing the surroundings, an empty cell with a cell gap of about 4μm is produced. At this time, regardless of whether the first substrate is rubbed or not, the direction of the comb electrode of the first substrate is parallel to the rubbing direction of the second substrate.

In this empty cell, liquid crystal (MLC-3019 made by Merck with 10wt% HMA and chiral dopant S-5011 added) is vacuum injected at room temperature, and the injection port is sealed to obtain a liquid crystal cell. The obtained liquid crystal cell constitutes an FFS mode liquid crystal display element. The obtained liquid crystal cell is then heated at 120°C for 20 minutes.

When UV treatment is performed, a high-pressure mercury lamp is used to irradiate the liquid crystal cell with ultraviolet light at an energy conversion of 365nm through a high-pass filter with a wavelength of 300nm, so that the exposure amount becomes 5000mJ/ ^cm2 .

<Evaluation of liquid crystal alignment>

Use a polarizing plate installed in cross nicol to confirm the alignment of the liquid crystal cell. Those with no defects and alignment are rated as ○, those with slight alignment defects are rated as △, and those without alignment are rated as ×.

<Measurement of V-T curve and evaluation of driving threshold voltage and minimum brightness voltage>

The white LED backlight and brightness meter are installed in a way that the optical axis is aligned. The liquid crystal cell (liquid crystal display element) with a polarizing plate installed is placed between them in a way that the brightness is maximized. The voltage is applied at intervals of 1V up to 8V, and the brightness of the voltage is measured to implement the measurement of the V-T curve. The driving threshold voltage and the voltage value at which the brightness is minimized are estimated from the obtained V-T curve.

<Evaluation of the response speed of liquid crystal display>

Using the device used for measuring the V-T curve above, connect the brightness meter to the oscilloscope and measure the response speed (Ton) when the voltage that results in minimum brightness is applied and the response speed (Toff) when the voltage is 0.

When the FFS substrate side was not rubbed, the horizontal alignment could not be confirmed even if the back ITO side was rubbed. Severe flow alignment was confirmed. On the other hand, when the rubbing treatment was performed, all except the one without film showed twisted alignment.

When driving this twisted alignment cell, the minimum voltage for brightness becomes above 10V, and even if a voltage above 20V is applied, the display will not be completely black.

For the unrubbed FFS substrate side, the liquid crystal orientation cannot be confirmed, but if UV is irradiated, samples with twisted orientation will appear (Cell-11', Cell-12'). On the other hand, Cell-13'~Cell-15' do not show orientation and are in a non-orientation state. From this, it can be considered that the orientation film with an organic group that shows free radical polymerization will make the liquid crystal align. It can be confirmed that the voltage that becomes the lowest brightness when driving is applied has dropped significantly, and it is displayed black.

It was found that among the samples treated with friction and UV irradiation, the driving threshold voltage and minimum brightness voltage of Cell-16' and Cell-17' were not only reduced, but the Toff value was also greatly improved. On the other hand, Cell-18'~Cell-20' had the same results as those without UV irradiation, and it was judged that there was no change. It can be considered that such characteristic behavior can be produced by using an alignment film containing an organic group with free radical polymerizability and a liquid crystal containing a polymerizable compound and performing UV irradiation treatment.

As for the supplementary experiment, when using liquid crystals without chiral dopants, the crystal cells using UVAL-1 and AL-2 and applying UV to the crystal cells are all horizontally aligned, regardless of whether they are rubbed or not, and the twisted alignment action cannot be verified.

[Industrial Utilization]

According to the present invention, zero-surface anchoring films can be industrially produced with good efficiency from low-cost raw materials. In addition, the liquid crystal display element obtained by the method of the present invention is useful as a vertical alignment liquid crystal display element such as a PSA type liquid crystal display, a SC-PVA type liquid crystal display, etc.

Claims (18)

A method for manufacturing a liquid crystal cell comprises the following steps: preparing a first substrate having a free radical generating film and a second substrate which may also have a free radical generating film; manufacturing a cell in a manner that the free radical generating film on the first substrate faces the second substrate; and filling a liquid crystal composition containing a liquid crystal, a chiral dopant and a free radical polymerizable compound between the first substrate and the second substrate, and comprising the following steps: providing a liquid crystal composition containing a liquid crystal, a chiral dopant and a free radical polymerizable compound with a state in which the liquid crystal composition containing a liquid crystal, a chiral dopant and a free radical polymerizable compound contacts the free radical generating film. The free radical polymerizable compound has sufficient energy for a polymerization reaction. The free radical generating film is obtained by coating and curing a composition of a compound having a radical generating group and a polymer to form a film so as to fix the free radical generating film in the film. The free radical generating film of the first substrate is a free radical generating film treated with uniaxial alignment. At least one of the free radical polymerizable compounds is a compound having one polymerizable unsaturated bond in one molecule and having compatibility with liquid crystal. The polymerizable unsaturated bond of the free radical polymerizable compound is selected from the following structures:

In the formula, * represents the bonding site with the compound molecule other than the polymerizable unsaturated bond. For example, in the method for manufacturing a liquid crystal cell in Item 1 of the patent application, the step of providing energy is performed in the absence of an electric field. For example, in the method for manufacturing a liquid crystal cell of item 1 or 2 of the patent application, the free radical generating film is a film formed by fixing an organic group that induces free radical polymerization. For example, in the method for manufacturing a liquid crystal cell of item 1 or 2 of the patent application, the free radical generating film is composed of a polymer containing an organic group that induces free radical polymerization. For example, in the method for manufacturing a liquid crystal cell of item 4 of the patent application, the polymer containing an organic group that induces free radical polymerization is at least one polymer selected from polyimide precursors, polyimide, polyurea and polyamide obtained by using a diamine component containing a diamine containing an organic group that induces free radical polymerization. For example, in the method for manufacturing a liquid crystal cell of item 3 of the patent application, the organic group inducing free radical polymerization is an organic group represented by the following structures [X-1] to [X-14], [W], [Y], [Z];

In formulas [X-1] to [X-14], * represents a bonding site with a portion other than a polymerizable unsaturated bond of a compound molecule, S ¹ and S ² each independently represent -O-, -NR-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, 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, and R ¹ and R ² each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms;

In the formulas [W], [Y], and [Z], * represents a bonding site with a portion other than a polymerizable unsaturated bond of a compound molecule, Ar represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene, and biphenylene which may have an organic group and/or a halogen atom as a substituent, ^R9 and ^R10 each independently represent an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, and when ^R9 and ^R10 are alkyl groups, they may be bonded to each other at the ends to form a ring structure; Q represents any of the following structures;

In the formula, R ¹¹ represents -CH ₂ -, -NR-, -O-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, * represents a bonding site with a portion other than Q of the compound molecule; 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. For example, in the method for manufacturing a liquid crystal cell of item 4 of the patent application, the organic group inducing free radical polymerization is an organic group represented by the following structures [X-1] to [X-14], [W], [Y], [Z];

In formulas [X-1] to [X-14], * represents a bonding site with a portion other than a polymerizable unsaturated bond of a compound molecule, S ¹ and S ² each independently represent -O-, -NR-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, 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, and R ¹ and R ² each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms;

In the formulas [W], [Y], and [Z], * represents a bonding site with a portion other than a polymerizable unsaturated bond of a compound molecule, Ar represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene, and biphenylene which may have an organic group and/or a halogen atom as a substituent, ^R9 and ^R10 each independently represent an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, and when ^R9 and ^R10 are alkyl groups, they may be bonded to each other at the ends to form a ring structure; Q represents any of the following structures;

In the formula, R ¹¹ represents -CH ₂ -, -NR-, -O-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, * represents a bonding site with a portion other than Q of the compound molecule; 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. For example, in the method for manufacturing a liquid crystal cell of claim 5, the organic group inducing free radical polymerization is an organic group represented by the following structures [X-1] to [X-14], [W], [Y], [Z];

In formulas [X-1] to [X-14], * represents a bonding site with a portion other than a polymerizable unsaturated bond of a compound molecule, S ¹ and S ² each independently represent -O-, -NR-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, 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, and R ¹ and R ² each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms;

In the formulas [W], [Y], and [Z], * represents a bonding site with a portion other than a polymerizable unsaturated bond of a compound molecule, Ar represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene, and biphenylene which may have an organic group and/or a halogen atom as a substituent, ^R9 and ^R10 each independently represent an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, and when ^R9 and ^R10 are alkyl groups, they may be bonded to each other at the ends to form a ring structure; Q represents any of the following structures;

In the formula, R ¹¹ represents -CH ₂ -, -NR-, -O-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, * represents a bonding site with a portion other than Q of the compound molecule; 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. In the method for manufacturing a liquid crystal cell of claim 5, the diamine containing an organic group inducing free radical polymerization is a diamine having a structure represented by the following general formula (6) or the following general formula (7);

In formula (6), R ⁶ represents 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 ⁷ represents a single bond, or an unsubstituted or fluorine-substituted alkylene group having 1 to 20 carbon atoms; any one or more of -CH ₂ - or -CF ₂ - in the alkylene group may be independently replaced by a group selected from -CH=CH-, a divalent carbon ring, and a divalent heterocyclic ring; further, any one of the following groups, i.e., -O-, -COO-, -OCO-, -NHCO-, -CONH-, or -NH- may be replaced by these groups provided that they are not adjacent to each other; R ⁸ represents a free radical polymerization reactive group selected from the following formulae;

In formulas [X-1] to [X-14], * represents a bonding site with a portion other than a radical polymerization-reactive group of a compound molecule, S ¹ and S ² each independently represent -O-, -NR-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, 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, and R ¹ and R ² each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms;

In formula (7), ^T1 and ^T2 are each independently -O-, -S-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, _-CH2O- , -N( _CH3 )-, -CON( _CH3 )-, or -N( _CH3 )CO-, S represents a single bond, or an unsubstituted or fluorine-substituted alkylene group having 1 to 20 carbon atoms, any _-CH2- or _-CF2- of the alkylene group -One or more of - may be independently replaced by a group selected from -CH=CH-, a divalent carbon ring, and a divalent heterocyclic ring. Furthermore, any of the following groups, i.e., -O-, -COO-, -OCO-, -NHCO-, -CONH-, or -NH-, may be replaced by these groups provided that they are not adjacent to each other. J is an organic group represented by the following formula:

In the formulas [W], [Y], and [Z], * represents a bonding site with ^T2 , Ar represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene, and biphenylene which may have an organic group and/or a halogen atom as a substituent, ^R9 and ^R10 each independently represent an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, and Q represents any of the following structures;

In the formula, R ¹¹ represents -CH ₂ -, -NR-, -O-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, * represents a bonding site with a portion other than Q of the compound molecule; 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. For example, in the method for manufacturing a liquid crystal cell of item 1 or 2 of the patent application, the liquid crystal composition containing liquid crystal, chiral dopant and free radical polymerizable compound contains a free radical polymerizable compound whose Tg of the polymer obtained by polymerizing the free radical polymerizable compound is below 100°C. For example, in the method for manufacturing a liquid crystal cell in Item 1 of the patent application, the second substrate is a second substrate without a free radical generating film. For example, the manufacturing method of the liquid crystal cell in item 11 of the patent application scope, wherein the second substrate is coated with a liquid crystal alignment film having uniaxial alignment. For example, the manufacturing method of the liquid crystal cell in item 12 of the patent application scope, wherein the liquid crystal alignment film with uniaxial alignment is a liquid crystal alignment film for horizontal alignment. A method for manufacturing a liquid crystal cell as claimed in any one of items 1, 11 to 13 of the patent application, wherein the first substrate having a free radical generating film is a substrate having a comb-tooth electrode. A method for manufacturing a liquid crystal display element is a method for manufacturing a liquid crystal display element using a film that produces a zero-plane anchoring state, and the film that produces a zero-plane anchoring state is obtained using a method such as any one of items 1 to 14 of the patent application scope. A liquid crystal display element is obtained using the manufacturing method of the liquid crystal display element as described in item 15 of the patent application scope. For example, in the liquid crystal display element of item 16 of the patent application, the first substrate or the second substrate has an electrode. If the liquid crystal display element in item 16 or 17 of the patent application scope is a low voltage driven transverse electric field liquid crystal display element.