CN114868076A

CN114868076A - Radical generating film forming composition, radical generating film, and method for producing horizontal electric field liquid crystal cell

Info

Publication number: CN114868076A
Application number: CN202080087937.0A
Authority: CN
Inventors: 野田尚宏
Original assignee: Nissan Chemical Corp
Current assignee: Nissan Chemical Corp
Priority date: 2019-12-18
Filing date: 2020-12-18
Publication date: 2022-08-05
Also published as: KR20220116206A; WO2021125329A1; TW202132412A; JPWO2021125329A1

Abstract

The present invention provides a radical generating film forming composition which, when used in a horizontal electric field liquid crystal display element, can realize good black display and can realize high backlight transmittance and high response speed. The composition for forming a radical generating film contains a component (A) which is a polymer having a structural unit represented by the formula (1) in the main chain and a component (B) which is a polymer used as an alignment component of a liquid crystal alignment agent for driving a horizontal electric field:

Description

Radical generating film forming composition, radical generating film, and method for producing horizontal electric field liquid crystal cell

Technical Field

The present invention relates to a radical generating film forming composition and a radical generating film which can be suitably used for weakly anchored liquid crystal display elements and the like.

The present invention also relates to a method for producing a horizontal electric field liquid crystal cell using the radical generating film forming composition or the radical generating film.

Background

In recent years, liquid crystal display elements have been widely used in displays of mobile phones, computers, and televisions. Liquid crystal display elements have characteristics such as thin thickness, light weight, and low power consumption, and are expected to be applied to more fields such as VR (Virtual Reality) and ultra-fine displays in the future. Various display modes such as TN (Twisted Nematic), IPS (In-Plane Switching), VA (Vertical Alignment), and the like have been proposed as display modes of a liquid crystal display, but a film (liquid crystal Alignment film) In which liquid crystals are induced to a desired Alignment state is used In all modes.

In particular, in products having a touch panel such as a tablet PC, a smartphone, and a smart TV, an IPS mode in which display is not disturbed easily even when touched is preferable, and in recent years, technologies such as a liquid crystal display element using FFS (Fringe Field Switching) and a non-contact technology using photo-alignment have been adopted in order to improve contrast or to improve viewing angle characteristics.

In recent years, the brightness of the backlight has been increased with the aim of further increasing the definition and contrast of 4K, 8K, and the like. Accordingly, the liquid crystal display device is also aimed at improving the transmittance, lowering the driving voltage, and the like, and particularly, the FFS mode is used not only for TV applications but also for flat panels, smart phones, and the like, and therefore, it is a very important technical problem to improve the transmittance and lower the driving voltage.

As for the improvement of the transmittance of the liquid crystal display element, a method using a negative liquid crystal is recommended for the FFS mode, and practical use is being promoted. On the other hand, when a negative liquid crystal is used, although the effect of improving the transmittance is large, there is a problem that the effect of reducing the power consumption is poor, the negative liquid crystal itself is likely to dissolve contaminants, and defects such as unevenness and ghosts are likely to occur, because the negative liquid crystal is accompanied by deterioration of the response time and increase of the driving voltage.

Recently, as a technique capable of improving the transmittance of a liquid crystal display element and reducing the driving voltage, a weakly anchored IPS technique using a film having a very low anchoring energy as a liquid crystal alignment film has been attracting attention. The weak anchor IPS technology has an advantage that, even when an IPS substrate having a comb-tooth electrode width that is somewhat wide is used as a substrate, transmittance can be greatly improved and a driving voltage can be reduced, and therefore, if the technology can be put to practical use, the substrate cost advantage becomes large, and the problem specific to the FFS mode, that is, occurrence of flicker can be suppressed (see patent document 1).

In recent years, a zero-plane anchoring state has been produced using a dense polymer brush or the like, and a technique of a zero-plane anchoring IPS mode (also referred to as a weak-anchoring IPS mode) has been proposed (see reference 2). By this technique, a contrast ratio is greatly improved or a driving voltage is greatly reduced.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 4053530

Patent document 2: japanese patent laid-open publication No. 2013-231757

Disclosure of Invention

Technical problem to be solved by the invention

However, this technique has a problem in principle, and first, in order to stably produce a polymer brush on a substrate, it is necessary to perform the process under very detailed conditions, which is not practical from the viewpoint of mass production. Second, the alignment film plays an important role in suppressing ghost images and the like, but it is difficult to control desired electrical properties and the like when a polymer brush or the like is used. Third, in terms of driving principle, the response speed at the voltage Off is very slow. It is expected that the resistance applied to the liquid crystal during driving is eliminated by setting the alignment control force to zero, and the threshold voltage is greatly reduced, and it is also expected that the luminance is improved by reducing the defective alignment region during driving.

It is considered that if such a technical problem can be solved, there is a great advantage in cost for a panel manufacturer, and there is also an advantage in terms of suppressing battery consumption, improving image quality, and the like.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a horizontal electric field liquid crystal display element capable of simultaneously realizing non-contact alignment, reduction in driving voltage, and improvement in response speed at voltage Off, by a simple and inexpensive method at room temperature, by applying a polymer stabilization technique capable of producing a weak anchor film.

In particular, an object of the present invention is to provide a horizontal electric field liquid crystal display element capable of realizing excellent black display, and also capable of realizing high backlight transmittance and high response speed.

Further, another object of the present invention is to provide a composition for forming a radical generating film for use in such a horizontal electric field liquid crystal display element, in order to obtain such an excellent horizontal electric field liquid crystal display element.

Means for solving the problems

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved, and have completed the present invention having the following gist.

That is, the present invention includes the following aspects.

[1] A composition for forming a radical generating film, comprising a component (A) which is a polymer having a structural unit represented by the following formula (1) in the main chain and a component (B) which is a polymer used as an alignment component of a liquid crystal alignment agent for horizontal electric field driving:

[ solution 1]

(in formula (1), A represents an organic group that initiates radical polymerization).

[2] The composition for forming a free-radical generating film according to [1], wherein the polymer as the component (A) is at least one polymer selected from a polyimide precursor obtained by using a diamine component containing a diamine containing an organic group that initiates radical polymerization, a polyimide, a polyurea and a polyamide.

[3] The radical generating film forming composition according to [2], wherein the diamine containing an organic group which initiates radical polymerization is a diamine represented by the following formula (2):

[ solution 2]

(in the formula (2), A ¹ And A ² Each represents a hydrogen atom or an organic group which initiates radical polymerization, wherein A ¹ And A ² At least one of which represents an organic group that initiates radical polymerization,

e represents a single bond, -O-, -C (CH) ₃ ) ₂ -、-NH-、-CO-、-NHCO-、-COO-、-(CH ₂ ) _m -、-SO ₂ Or a 2-valent organic group composed of any combination thereof, and m represents an integer of 1 to 8.

p represents an integer of 0 to 2; when p is 2, a plurality of A ² Each independently has the foregoing definitions; in addition, when p is 0, A ¹ Consisting of organic groups which initiate free radical polymerization. ).

[4] The radical generating film forming composition according to any one of [1] to [3], wherein the radical polymerization initiating organic group is a group represented by the following formula (3):

[ solution 3]

----R ⁶ -R ⁷ -R ⁸ (3)

(in the formula (3), the dotted line represents a bond to a benzene ring, 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 alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted with a fluorine atom, or any of-CH's of the alkylene groups ₂ -or-CF ₂ 1 or more of-may be independently replaced with a group selected from-CH-, a 2-valent carbocyclic ring and a 2-valent heterocyclic ring, and further, may be replaced with any of the groups mentioned below, i.e., -O-, -COO-, -OCO-, -NHCO-, -CONH-, or-NH-without being adjacent to each other.

R ⁸ Is represented by a group selected from the formula [ X-1 ]]～[X-18]、[W]、[Y]And [ Z]An organic group which initiates radical polymerization, represented by the formula (1):

[ solution 4]

Formula [ X-1]～[X-18]Wherein represents a bond to R ⁷ Site of (A), S ₁ And S ₂ Each independently represents-O-, -NR-, or-S-, R 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, R represents ₁ And R ₂ Each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms,

[ solution 5]

Formula [ W ]]、[Y]、[Z]Wherein denotes a bond to R ⁷ Site of (A), S ³ Represents a single bond, -O-, -S-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-、-N(CH ₃ )-、-CON(CH ₃ ) -, or-N (CH) ₃ ) CO-, 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, and R ⁹ And R ¹⁰ Each independently is a carbon atomAlkyl, alkoxy, benzyl or phenethyl with a sub-number of 1-10, in case of alkyl or alkoxy, R can be substituted by ⁹ And R ¹⁰ Forming a ring,

q represents any one of the following structures,

[ solution 6]

In the formula, R ¹¹ represents-CH ₂ -, -NR-, -O-, or-S-, wherein R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and represents a bond,

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. ).

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

[6] A method of fabricating a horizontal electric field liquid crystal cell, comprising:

a step of preparing a first substrate having a liquid crystal alignment film and a second substrate having the radical generating film described in [5 ];

a step of forming a cell so that the radical generating film on the second substrate faces the first substrate; and

a step of filling a liquid crystal composition containing a liquid crystal and a radical polymerizable compound between the first substrate and the second substrate,

one of the first substrate and the second substrate is a comb-teeth electrode substrate, and the other is an opposing substrate.

[7] The method of manufacturing a horizontal electric field liquid crystal cell according to [6], wherein the first substrate is a substrate covered with a liquid crystal alignment film having uniaxial alignment properties.

[8] The method of manufacturing a horizontal electric field liquid crystal cell according to [7], wherein the liquid crystal alignment film having a uniaxial alignment property is a liquid crystal alignment film for horizontal alignment.

[9] The method of manufacturing a horizontal electric field liquid crystal cell according to any one of [6] to [8], wherein the comb-teeth electrode substrate is an IPS substrate or an FFS substrate.

Effects of the invention

According to the present invention, in order to obtain a horizontal electric field liquid crystal display element capable of realizing a good black display, and capable of realizing a high backlight transmittance and a high response speed, a radical generating film forming composition capable of being effectively used in the horizontal electric field liquid crystal display element is provided.

Drawings

Fig. 1 is a schematic cross-sectional view showing an example of a liquid crystal display element of the present invention.

Fig. 2 is a schematic cross-sectional view showing another example of the liquid crystal display element of the present invention.

Detailed Description

(composition for forming free radical-generating film)

The radical generating film-forming composition of the present invention contains the component (A) and the component (B).

< ingredient (A) >

The present invention contains a polymer having a structural unit represented by the above formula (1) in the main chain as the component (a). As a result, the radical generating film forming composition of the present invention contains an organic group which initiates radical polymerization. By applying such a composition and curing the composition to form a film, a liquid crystal alignment film having various functions in which a group capable of generating a radical is fixed to the film can be obtained.

Examples of the organic group that initiates radical polymerization include groups represented by the above formula (3).

The organic group represented by a formula selected from the group consisting of [ W ], [ Y ] and [ Z ] is particularly preferably the following organic group. In particular, (b) and (c) are preferable from the viewpoint of reliability of the obtained liquid crystal display element.

[ solution 7]

When the polymer having an organic group that initiates radical polymerization, which is used in the present invention as component (a), is used, it is preferable to produce the polymer having a group capable of generating a radical, by using, as a monomer component, a monomer having a photoreactive side chain containing at least one selected from the group consisting of a methacryloyl group (japanese: メタクリル group), an acryloyl group (japanese: アクリル group), a vinyl group, an allyl group, a coumarinyl group, a styryl group, and a cinnamoyl group, and a monomer that is decomposed by ultraviolet irradiation and has a site that generates a radical on the side chain. On the other hand, since a monomer generating a radical forms an unstable compound by spontaneously polymerizing itself, it is considered that a polymer derived from a diamine having a radical generating site is preferable in terms of ease of synthesis, and polyimide precursors such as polyamic acid and polyamic acid ester, polyimide, polyurea, and polyamide are more preferable.

Specifically, the diamine containing a radical generating site is, for example, a diamine having a side chain capable of generating a radical and performing polymerization, and examples thereof include a diamine represented by the above formula (2), but the diamine is not limited thereto.

In the above formula (2), E represents a single bond, -O-, -C (CH) ₃ ) ₂ -、-NH-、-CO-、-NHCO-、-COO-、-(CH ₂ ) _m -、-SO ₂ Or a 2-valent organic group composed of any combination thereof, wherein the "any combination thereof" includes: -O- (CH) ₂ ) _m -O-、-O-C(CH ₃ ) ₂ -、-CO-(CH ₂ ) _m -、-NH-(CH ₂ ) _m -、-SO ₂ -(CH ₂ ) _m -、-CONH-(CH ₂ ) _m -、-CONH-(CH ₂ ) _m -NHCO-、-COO-(CH ₂ ) _m -OCO-, etc., but is not limited thereto.

Two amino groups (-NH) in the diamine having a radical-generating site (specifically, for example, formula (2)) (see ₂ ) The bonding position of (2) is not limited. Specifically, examples of the bonding group to the side chain include 2,3, 2,4, 2,5, 2,6, 3,4, and 3,5 positions on the benzene ring. Wherein the reaction from the synthesis of polyamic acidFrom the viewpoint of compatibility, the 2,4-, 2, 5-or 3, 5-position is preferable. Further, considering the easiness of synthesizing the diamine, the 2, 4-position or 3, 5-position is more preferable.

Specific examples of the diamine having a photoreactive group include, but are not limited to, compounds containing at least one selected from the group consisting of a methacryloyl group, an acryloyl group, a vinyl group, an allyl group, a coumarinyl group, a styryl group, and a cinnamoyl group.

[ solution 8]

[ solution 9]

(in the formula, J ¹ Represents a single bond, -O-, -COO-, -NHCO-, or-NH-, J ² Represents a single bond or an alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted with a fluorine atom. ).

The diamine having an organic group represented by a formula selected from the group consisting of [ W ], [ Y ] and [ Z ] is most preferably a structure represented by the following formula in view of ease of synthesis, versatility, properties, and the like, but is not limited thereto.

[ solution 10]

(wherein n is an integer of 2 to 8, E is a single bond, -O-, -C (CH) ₃ ) ₂ -、-NH-、-CO-、-NHCO-、-COO-、-(CH ₂ ) _m -、-SO ₂ -、-O-(CH ₂ ) _m -O-、-O-C(CH ₃ ) ₂ -、-CO-(CH ₂ ) _m -、-NH-(CH ₂ ) _m -、-SO ₂ -(CH ₂ ) _m -、-CONH-(CH ₂ ) _m -、-CONH-(CH ₂ ) _m -NHCO-, or-COO-(CH ₂ ) _m -OCO-, m is an integer of 1 to 8. ).

[ solution 11]

(wherein n is an integer of 2 to 8).

The diamine may be used alone or in combination of two or more depending on the characteristics such as liquid crystal alignment property when a radical generating film is formed, sensitivity in polymerization reaction, voltage holding property, and accumulated charge.

The diamine having a site where radical polymerization occurs is preferably used in an amount of 5 to 100 mol%, more preferably 10 to 80 mol%, and particularly preferably 30 to 50 mol% based on the total amount of the diamine component used for synthesizing the polymer as the component (a) contained in the radical generating film forming composition.

In addition, in the case where the polymer used as the component (a) in the radical generating film forming composition of the present invention is obtained from a diamine, a diamine other than the above-mentioned diamine having a radical generating site may be used in combination as the diamine component. Specifically, there may be mentioned: p-phenylenediamine, 2,3,5, 6-tetramethyl-p-phenylenediamine, 2, 5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2, 4-dimethyl-m-phenylenediamine, 2, 5-diaminotoluene, 2, 6-diaminotoluene, 2, 5-diaminophenol, 2, 4-diaminophenol, 3, 5-diaminobenzyl alcohol, 2, 4-diaminobenzyl alcohol, 4, 6-diaminoresorcinol, 4 '-diaminobiphenyl, 3' -dimethyl-4, 4 '-diaminobiphenyl, 3' -dimethoxy-4, 4 '-diaminobiphenyl, 3' -dihydroxy-4, 4 '-diaminobiphenyl, 2, 4-dimethyl-m-phenylenediamine, 2, 4-diaminotoluene, 2, 5-diaminophenol, 3, 5-diaminobenzyl alcohol, 2, 4-diaminobenzyl alcohol, 4, 6-diaminoresorcinol, 4' -diaminobiphenyl, 3 '-dimethoxy-4, 4' -diaminobiphenyl, 3 '-dihydroxy-4, 4' -diaminobiphenyl, 2, 5-dimethyl-p-phenylenediamine, 2, 4-m-phenylenediamine, 2, 4-diaminobiphenyl, 4-m-xylene, 2, 4-diaminobiphenyl, 4, and a, 3,3 ' -dicarboxy-4, 4 ' -diaminobiphenyl, 3 ' -difluoro-4, 4 ' -diaminobiphenyl, 3 ' -bis (trifluoromethyl) -4,4 ' -diaminobiphenyl, 3 ' -diaminobiphenyl, 2 ' -diaminobiphenyl, 2,3 ' -diaminobiphenyl, 4 ' -diaminodiphenylmethane, 3 ' -diaminodiphenylmethane, 3,4 ' -diaminodiphenylmethane, 2 ' -diaminodiphenylmethane, 2,3 ' -diaminodiphenylmethane, 4 ' -diaminodiphenyl ether, 3 ' -diaminodiphenyl ether, 3,4 ' -diaminodiphenyl ether, 2,2 ' -diaminodiphenyl ether, 2,3 ' -diaminodiphenyl ether, 4 ' -sulfonyldiphenylamine, 3 ' -sulfonyldiphenylamine, bis (4-aminophenyl) silane, bis (3-aminophenyl) silane, dimethyl-bis (4-aminophenyl) silane, dimethyl-bis (3-aminophenyl) silane, 4 ' -thiodiphenylamine, 3 ' -thiodiphenylamine, 4 ' -diaminodiphenylamine, 3 ' -diaminodiphenylamine, 3,4 ' -diaminodiphenylamine, 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 (3,3 ' -diaminodiphenyl) amine, N-methyl (3-amino) silane, 3 ' -sulfonyldiphenylamine, 3 ' -diphenylamine, 3 ' -thiodiphenylamine, 3 ' -thiodiphenylamine, and the like, N-methyl (3,4 ' -diaminodiphenyl) amine, N-methyl (2,2 ' -diaminodiphenyl) amine, N-methyl (2,3 ' -diaminodiphenyl) amine, 4 ' -diaminobenzophenone, 3 ' -diaminobenzophenone, 3,4 ' -diaminobenzophenone, 2 ' -diaminobenzophenone, 2,3 ' -diaminobenzophenone, 1, 4-diaminonaphthalene, 1, 5-diaminonaphthalene, 1, 6-diaminonaphthalene, 1, 7-diaminonaphthalene, 1, 8-diaminonaphthalene, 2, 5-diaminonaphthalene, 2, 6-diaminonaphthalene, 2, 7-diaminonaphthalene, 1, 2-bis (4-aminophenyl) ethane, 1, 2-bis (3-aminophenyl) ethane, N-methyl (2,2 ' -diaminodiphenyl) amine, N-methyl (2,3 ' -diaminodiphenyl) amine, 4 ' -diaminodiphenyl ketone, 3 ' -diaminodiphenyl ketone, 3,4 ' -diaminodiphenyl ketone, 2,3 ' -diaminonaphthalene, 2 ' -diaminonaphthalene, 2-diaminonaphthalene, 1, 2-bis (4-aminophenyl) ethane, 1, 2-bis (4-amino) ethane, 2-bis (4-amino) ethane, 1, 2-bis (3-amino) ethane, 2-bis (4-amino) ethane, 2-bis (4-phenyl) ethane, 2-bis (3-bis (4-amino) ethane, 2-bis (2-amino) ethane, 2-bis (2-amino) ethane, 2-bis (2-amino) ethane, 2-bis (4-bis (2-amino) ethane, 2-bis (2-amino) ethane, 2-amino) naphthalene), 2-bis (2-amino) ethane, 2-bis (2-amino) naphthalene), 2-bis (4-bis (2-bis) ethane, 2-bis (4-bis (2-bis (4-bis) ethane, 2-bis (2-, 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) methane, 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 '- [1, 4-phenylenebis (methylene) ] diphenylamine, 4' - [1, 3-phenylenebis (methylene) ] diphenylamine, 3,4 '- [1, 4-phenylenebis (methylene) ] diphenylamine, 3, 4' - [1, 3-phenylenebis (methylene) ] diphenylamine, 3 '- [1, 4-phenylenebis (methylene) ] diphenylamine, 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 '- (1, 4-phenylene) bis (4-aminobenzamide), N' - (1, 3-phenylene) bis (4-aminobenzamide), N '- (1, 4-phenylene) bis (3-aminobenzamide), N' - (1, 4-aminobenzamide), N '- (1, 3-phenylene) bis (3-aminobenzamide), N' -bis (4-aminophenyl) terephthalamide, N, N ' -bis (3-aminophenyl) terephthalamide, N ' -bis (4-aminophenyl) isophthalamide, N ' -bis (3-aminophenyl) isophthalamide, 9, 10-bis (4-aminophenyl) anthracene, 4 ' -bis (4-aminophenoxy) diphenylsulfone, 2 ' -bis [4- (4-aminophenoxy) phenyl ] propane, 2 ' -bis [4- (4-aminophenoxy) phenyl ] hexafluoropropane, 2 ' -bis (4-aminophenyl) hexafluoropropane, 2 ' -bis (3-amino-4-methylphenyl) hexafluoropropane, N ' -bis (4-aminophenyl) isophthalamide, N ' -bis (3-aminophenyl) isophthalamide, 9, 10-bis (4-aminophenyl) anthracene, 4 ' -bis (4-aminophenoxy) diphenylsulfone, 2 ' -bis [4- (4-aminophenoxy) phenyl ] propane, 2 ' -bis [4- (4-aminophenoxy) phenyl ] hexafluoropropane, 2,2 '-bis (4-aminophenyl) propane, 2' -bis (3-amino-4-methylphenyl) propane, trans-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 (3-aminophenoxy) propane, 1, 4-bis (4-aminophenoxy) butane, 1, 4-bis (3-aminophenoxy) butane, 1, 5-bis (4-aminophenoxy) pentane, 2 '-bis (3-aminophenyl) propane, 2' -bis (3-aminophenyl) propane, trans-1, 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) pentane, 1, 3-bis (4-aminophenoxy) pentane, 1, 5-pentane, 1, 4-pentane, 3-bis (4-aminophenoxy) pentane, 1, 3-pentane, 3-bis (4-amino-4-pentane, 1, 3-4-n-pentane, 3-n-2, 3-hexane, 1, 3-hexane, 1, 3-hexane, 2, 3-hexane, or toluene, 3-hexane, or one, or one, or more, 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) octane, 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, Aromatic diamines such as 1, 12-bis (4-aminophenoxy) dodecane and 1, 12-bis (3-aminophenoxy) dodecane; alicyclic diamines such as bis (4-aminocyclohexyl) methane and bis (4-amino-3-methylcyclohexyl) methane; aliphatic 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, and 1, 12-diaminododecane; diamines having a urea structure such as 1, 3-bis [2- (p-aminophenyl) ethyl ] urea, 1, 3-bis [2- (p-aminophenyl) ethyl ] -1-tert-butoxycarbonylurea, and the like; diamines having a nitrogen-containing unsaturated heterocyclic structure, such as N-p-aminophenyl-4-p-aminophenyl (tert-butoxycarbonyl) aminomethylpiperidine; diamines having an N-Boc group (Boc represents a tert-butoxycarbonyl group) such as N-tert-butoxycarbonyl-N- (2- (4-aminophenyl) ethyl) -N- (4-aminobenzyl) amine, and the like.

The other diamines may be used singly or in combination of two or more depending on the properties such as liquid crystal alignment properties when a radical generating film is formed, sensitivity in polymerization reaction, voltage holding properties, and accumulated charges.

In the synthesis of the polymer being a polyamic acid, the tetracarboxylic dianhydride to be reacted with the diamine component is not particularly limited. Specific examples thereof include: 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-bis (3, 4-dicarboxyphenyl) propane, 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 ', 4, 4' -diphenylsulfonetetracarboxylic acid, 3,4,9, 10-perylenetetracarboxylic acid, 1, 3-diphenyl-1, 2,3, 4-cyclobutanetetracarboxylic acid, oxydiphthalic tetracarboxylic 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, 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-naphthalenecarboxylic 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, 4,8, 10-tetracarboxylic acid, tricyclo [6.3.0.0<2,6> ] undecane-3, 5,9, 11-tetracarboxylic acid, 1,2,3, dianhydride of tetracarboxylic acid such as 4-butanetetracarboxylic acid, 4- (2, 5-dioxotetrahydrofuran-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-dioxotetrahydrofuryl) -3-methyl-3-cyclohexane-1, 2-dicarboxylic acid, tetracyclo [6.2.1.1<3,6> ] 0<2,7> ] dodecane-4, 5,9, 10-tetracarboxylic acid, 3,5, 6-tricarboxynorbornane-2: 3,5: 6-dicarboxylic acid, and 1,2,4, 5-cyclohexanetetracarboxylic acid.

Of course, the tetracarboxylic dianhydride may be used alone or in combination of two or more depending on the characteristics such as liquid crystal alignment property, sensitivity in polymerization reaction, voltage holding property, and accumulated charge when a radical generating film is formed.

In the synthesis of the polymer as a polyamic acid ester, the structure of the tetracarboxylic acid dialkyl ester to be reacted with the diamine component is not particularly limited, and specific examples thereof are given below.

Specific examples of the aliphatic tetracarboxylic acid diester include: dialkyl 1,2,3, 4-cyclobutanetetracarboxylic acid, dialkyl 1, 2-dimethyl-1, 2,3, 4-cyclobutanetetracarboxylic acid, dialkyl 1, 3-dimethyl-1, 2,3, 4-cyclobutanetetracarboxylic acid, dialkyl 1,2,3, 4-tetramethyl-1, 2,3, 4-cyclobutanetetracarboxylic acid, dialkyl 1,2,3, 4-cyclopentanetetracarboxylic acid, dialkyl 2,3,4, 5-tetrahydrofurantetracarboxylic acid, dialkyl 1,2,4, 5-cyclohexanetetracarboxylic acid, dialkyl 3, 4-dicarboxyl-1-cyclohexylsuccinate, dialkyl 3, 4-dicarboxyl-1, 2,3, 4-tetrahydro-1-naphthalenetetracarboxylic acid, 1, dialkyl 2,3, 4-butanetetracarboxylic acid ester, dialkyl bicyclo [3.3.0] octane-2, 4,6, 8-tetracarboxylic acid ester, dialkyl 3,3 ', 4' -dicyclohexyltetracarboxylic acid ester, dialkyl 2,3, 5-tricarboxycyclopentylacetate, cis-3, 7-dibutylcyclooctan-1, 5-diene-1, 2,5, 6-tetracarboxylic acid ester, dialkyl tricyclo [4.2.1.0<2,5> ] nonane-3, 4,7, 8-tetracarboxylic acid-3, 4:7, 8-dialkyl ester, hexacyclo [6.6.0.1<2,7>.0<3,6>.1<9,14> 0<10,13> ] hexadecane-4, 5,11, 12-tetracarboxylic acid 4,5:11, 12-dialkyl ester, 4- (2, 5-dioxotetrahydrofuran-3-yl) -1,2,3, 4-tetrahydronaphthalene-1, 2-dicarboxylic acid dialkyl ester, and the like.

Examples of the aromatic tetracarboxylic acid dialkyl ester include: dialkyl pyromellitate,

dialkyl

3,3 ', 4,4 ' -biphenyltetracarboxylic acid,

dialkyl

2,2 ', 3,3 ' -biphenyltetracarboxylic acid,

dialkyl

2,3,3 ', 4-biphenyltetracarboxylic acid,

dialkyl

3,3 ', 4,4 ' -benzophenonetetracarboxylic acid,

dialkyl

2,3,3 ', 4 ' -benzophenonetetracarboxylic acid, dialkyl bis (3, 4-dicarboxyphenyl) ether, dialkyl bis (3, 4-dicarboxyphenyl) sulfone,

dialkyl

1,2,5, 6-naphthalenetetracarboxylic acid,

dialkyl

2,3,6, 7-naphthalenetetracarboxylic acid, and the like.

In the synthesis of the polymer in the case of polyurea, the diisocyanate to be reacted with the diamine component is not particularly limited, and may be used according to availability and the like. Specific structures of the diisocyanates are shown below.

[ solution 12]

In the formula R ₂₂ And R ₂₃ Represents an aliphatic hydrocarbon having 1 to 10 carbon atoms.

The aliphatic diisocyanates represented by K-1 to K-5 have poor reactivity but have the advantage of improved solvent solubility; the aromatic diisocyanates represented by K-6 to K-7 have the effect of high reactivity and improved heat resistance, but have the disadvantage of, for example, reduced solubility in solvents. In terms of versatility and characteristics, K-1, K-7, K-8, K-9 and K-10 are particularly preferable, K-12 is preferable from the viewpoint of electrical characteristics, and K-13 is preferable from the viewpoint of liquid crystal alignment properties. The diisocyanate may be used in combination with one or more kinds thereof, and is preferably used in various applications depending on the desired properties.

In addition, a part of the diisocyanate may be replaced with the tetracarboxylic dianhydride described above, and may be used in the form of a copolymer of polyamic acid and polyurea, or may be used in the form of a copolymer of polyimide and polyurea by chemical imidization.

The structure of the dicarboxylic acid to be reacted in the synthesis of the polyamide polymer is not particularly limited, and specific examples thereof include the following. Specific examples of the aliphatic dicarboxylic acid include dicarboxylic acids such as malonic acid, oxalic acid, dimethylmalonic acid, succinic acid, fumaric acid, glutaric acid, adipic acid, hexadiene diacid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2-dimethylglutaric acid, 3-diethylsuccinic acid, azelaic acid, sebacic acid, and suberic acid.

Examples of the alicyclic dicarboxylic acid include: 1, 1-cyclopropanedicarboxylic acid, 1, 2-cyclopropanedicarboxylic acid, 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-cyclobutane-1, 2-dicarboxylic acid, 1-cyclobutane-3, 4-dicarboxylic acid, 1-cyclopentanedicarboxylic acid, 1, 2-cyclopentanedicarboxylic acid, 1, 3-cyclopentanedicarboxylic acid, 1-cyclohexanedicarboxylic acid, 1, 2-cyclohexanedicarboxylic acid, 1, 3-cyclohexanedicarboxylic acid, 1,4- (2-norbornene) dicarboxylic acid, 1, 3-cyclohexanedicarboxylic acid, 5-norbornene-2, 3-dicarboxylic acid, bicyclo [2.2.2] octane-1, 4-dicarboxylic acid, bicyclo [2.2.2] octane-2, 3-dicarboxylic acid, 2, 5-dioxo-1, 4-bicyclo [2.2.2] octane dicarboxylic acid, 1, 3-adamantanedicarboxylic acid, 4, 8-dioxo-1, 3-adamantanedicarboxylic acid, 2, 6-spiro [3.3] heptane dicarboxylic acid, 1, 3-adamantane diacetic acid, camphoric acid, etc.

Examples of the aromatic dicarboxylic acid include: phthalic acid, isophthalic acid, terephthalic acid, 5-methylisophthalic acid, 5-t-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-anthraquinone-dicarboxylic acid, 2, 5-biphenyldicarboxylic acid, 4 ' -biphenyldicarboxylic acid, 1, 5-biphenylenedicarboxylic acid, 4 ' -terphenyldicarboxylic acid, 4 ' -diphenylmethanedicarboxylic acid, 4 ' -diphenylethanedicarboxylic acid, 4 ' -diphenylpropanedicarboxylic acid, 5-aminoisophthalic acid, 5-hydroxyisophthalic acid, 2, 5-dimethylterephthalic acid, 2, 4-naphthalenedicarboxylic acid, 2, 5-naphthalenedicarboxylic acid, 2, 6-naphthalenedicarboxylic acid, 1, 4-naphthalenedicarboxylic acid, 4-anthracenedicarboxylic acid, 1, 4-anthraquinonedicarboxylic acid, 4-naphthalenedicarboxylic acid, 4-diphenylpropanedicarboxylic acid, 4-naphthalenedicarboxylic acid, 4-dicarboxylic acid, 4-naphthalenedicarboxylic acid, 4-dicarboxylic acid, 4-naphthalenedicarboxylic acid, and mixtures thereof, 4,4 ' -diphenylhexafluoropropane dicarboxylic acid, 4 ' -diphenyl ether dicarboxylic acid, 4 ' -dibenzyldicarboxylic acid, 4 ' -diphenylethylene dicarboxylic acid, 4 ' -diphenylacetylene dicarboxylic acid, 4 ' -carbonyldibenzoic acid, 4 ' -sulfonyldibenzoic acid, 4 ' -dithiodibenzoic acid, p-phenylenediacetic acid, 3 ' -p-phenylenedipropionic acid, 4-carboxycinnamic acid, p-phenylenediacrylic acid, 3 ' - [4,4 ' - (methylenedi-p-phenylene) ] dipropionic acid, 4 ' - [4,4 ' - (oxydiphenylene) ] dibutanoic acid, (isopropylidenediphenylenedioxy) dibutanoic acid, Dicarboxylic acids such as bis (p-carboxyphenyl) dimethylsilane.

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

The above-mentioned various dicarboxylic acids may be dicarboxylic acids having an acid dihalide or acid anhydride structure. From the viewpoint of maintaining the orientation of the liquid crystal molecules, these dicarboxylic acids are particularly preferably dicarboxylic acids of polyamide capable of forming a linear structure. Among them, terephthalic acid, isophthalic acid, 1, 4-cyclohexanedicarboxylic acid, 4 ' -diphenyldicarboxylic acid, 4 ' -diphenylmethanedicarboxylic acid, 4 ' -diphenylethanedicarboxylic acid, 4 ' -diphenylpropanedicarboxylic acid, 4 ' -diphenylhexafluoropropanedicarboxylic acid, 2-bis (phenyl) propanedicarboxylic acid, 4-terphenyldicarboxylic acid, 2, 6-naphthalenedicarboxylic acid, 2, 5-pyridinedicarboxylic acid, acid dihalides of these, and the like are preferably used. These compounds sometimes exist as isomers, and may be mixtures containing them. In addition, two or more compounds may be used in combination. The dicarboxylic acids used in the present invention are not limited to the above-mentioned exemplary compounds.

Examples of the polyimide having a 2-valent group represented by the formula (1) in the main chain include polyimides obtained by ring-closing the above polyimide precursor. In this polyimide, the ring closure rate of amic acid groups (also referred to as imidization rate) does not need to be always 100%, and can be adjusted as desired depending on the application or purpose.

Examples of the method for imidating the polyimide precursor include thermal imidation in which a solution of the polyimide precursor is directly heated, and catalytic imidation in which a catalyst is added to a solution of the polyimide precursor.

In the case of obtaining a polyamic acid, polyamic acid ester, polyurea, and polyamide by reacting a diamine (also referred to as "diamine component") as a raw material with a component selected from a tetracarboxylic dianhydride (also referred to as "tetracarboxylic dianhydride component"), a tetracarboxylic diester, a diisocyanate, and a dicarboxylic acid as a raw material, a known synthesis means can be used. In general, the method is a method of reacting a diamine component and one or more components selected from a tetracarboxylic dianhydride component, a tetracarboxylic diester, a diisocyanate, and a dicarboxylic acid in an organic solvent.

The reaction of the diamine component and the tetracarboxylic dianhydride component is advantageously carried out relatively easily in an organic solvent and does not produce a by-product.

The organic solvent used in the above reaction is not particularly limited as long as it dissolves the polymer produced. Further, even an organic solvent which does not dissolve the polymer may be used in combination with the above solvent within a range in which the polymer to be produced is not precipitated. Further, since water in the organic solvent causes inhibition of the polymerization reaction and hydrolysis of the polymer produced, it is preferable to use an organic solvent that has been dehydrated and dried.

Examples of the organic solvent include: n, N-dimethylformamide, N-dimethylacetamide, N-diethylformamide, N-methylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1, 3-dimethyl-2-imidazolidinone, 3-methoxy-N, N-dimethylpropionamide, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethylphosphoric triamide, gamma-butyrolactone, isopropanol, methoxymethylpentanol, dipentene, ethylpentyl ketone, methylnonyl ketone, methylethylketone, methylisoamylketone, methylisopropyl ketone, methylcellosolve, ethylcellosolve, methylcellosolve acetate, butylcellosolve acetate, and the like, Ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, 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 monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate 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, dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methylethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 2-ethyl-1-hexanol, and the like. These organic solvents may be used alone or in combination.

When the diamine component and the tetracarboxylic dianhydride component are reacted in an organic solvent, the following method can be mentioned: a method of stirring a solution obtained by dispersing or dissolving a diamine component in an organic solvent, and adding a tetracarboxylic dianhydride component as it is or dispersing or dissolving it in an organic solvent; conversely, a method of adding a diamine component to a solution obtained by dispersing or dissolving a tetracarboxylic dianhydride component in an organic solvent; a method of alternately adding the tetracarboxylic dianhydride component and the diamine component, and any of these methods can be used. In the case where the diamine component or the tetracarboxylic dianhydride component is composed of a plurality of compounds, these components may be reacted in a state of being mixed in advance, or they may be reacted in sequence, or low molecular weight materials obtained by the respective reactions may be further subjected to a mixing reaction to produce a high molecular weight material.

The temperature at which the diamine component and the tetracarboxylic dianhydride component are reacted may be selected from any temperature, for example, from-20 to 100 ℃, preferably from-5 to 80 ℃. The reaction can be carried out at any concentration, and for example, the total amount of the diamine component and the tetracarboxylic dianhydride component is 1 to 50% by mass, preferably 5 to 30% by mass, based on the reaction solution.

The ratio of the total mole number of the tetracarboxylic dianhydride component to the total mole number of the diamine component in the polymerization reaction can be arbitrarily selected depending on the desired molecular weight of the polyamic acid. As in the case of the usual polycondensation reaction, the closer the molar ratio is to 1.0, the larger the molecular weight of the polyamic acid produced. The preferable range is 0.8 to 1.2.

The method for synthesizing the polymer used in the present invention is not limited to the above method, and when synthesizing polyamic acid, the corresponding polyamic acid can be obtained by performing a reaction using a tetracarboxylic acid derivative such as a tetracarboxylic acid or a tetracarboxylic acid dihalide having a corresponding structure in place of the tetracarboxylic acid dianhydride by a known method, as in the case of a general method for synthesizing polyamic acid. In the case of synthesizing polyurea, a diamine may be reacted with a diisocyanate. In the production of the polyamic acid ester or the polyamide, the diamine and a component selected from the group consisting of a tetracarboxylic acid diester and a dicarboxylic acid may be derivatized to an acid halide in the presence of a known condensing agent or by a known method, and then reacted with the diamine.

Examples of the method for imidizing the polyamic acid to obtain a polyimide include thermal imidization in which a solution of the polyamic acid is directly heated, and imidization in which a catalyst is added to a solution of the polyamic acid. In addition, the imidization ratio of the polyamic acid to the polyimide is preferably 30% or more, and more preferably 30 to 99% from the viewpoint of being able to improve the voltage holding ratio. On the other hand, from the viewpoint of suppressing whitening properties, that is, precipitation of a polymer in a varnish, it is preferably 70% or less. The two characteristics are comprehensively considered, and the optimal selection is 40-80%.

The temperature at which the polyamic acid is thermally imidized in a solution is usually 100 to 400 ℃, preferably 120 to 250 ℃, and is preferably carried out while removing water generated by the imidization reaction from the system.

The catalytic imidization of the polyamic acid can be carried out by adding a basic catalyst and an acid anhydride to a solution of the polyamic acid and stirring at a temperature of usually-20 to 250 ℃ and preferably 0 to 180 ℃. The amount of the basic catalyst is usually 0.5 to 30 molar times, preferably 2 to 20 molar times of the amic acid group; the amount of the acid anhydride is usually 1 to 50 mol times, preferably 3 to 30 mol times of the amic acid group. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine, and among these, pyridine is preferable because it has an appropriate basicity for advancing the reaction. The acid anhydride includes acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like, and among these, acetic anhydride is preferable because purification after completion of the reaction is easier. The imidization rate based on the catalyst imidization can be controlled by adjusting the amount of the catalyst and the reaction temperature, the reaction time, and the like.

In the case of recovering the produced polymer from the polymer reaction solution, the reaction solution may be precipitated by charging the reaction solution with a lean solvent. Examples of the poor solvent for forming a precipitate include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, water, and the like. The polymer precipitated by charging into the lean solvent can be recovered by filtration and then dried at normal temperature or under reduced pressure or by heating. Further, if the operation of re-dissolving the polymer obtained by the precipitation and recovery in the organic solvent and re-precipitating and recovering is repeated 2 to 10 times, impurities in the polymer can be reduced. Examples of the lean solvent in this case include alcohols, ketones, hydrocarbons, and the like, and it is preferable to use 3 or more kinds of lean solvents selected from them because purification efficiency can be further improved.

The polymer as the component (a) of the present invention is more preferably at least one selected from a polyimide precursor containing a structural unit represented by the following formula (6) and a polyimide as an imide compound thereof, from the viewpoint of use as a liquid crystal aligning agent.

[ solution 13]

In the above formula (6), X ₁ Is a 4-valent organic radical from a tetracarboxylic acid derivative, Y ₁ Is a 2-valent organic radical from a diamine of the formula (2), R ₄ Is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. From the viewpoint of easiness of imidation by heating, R ₄ Preferably a hydrogen atom, a methyl group or an ethyl group.

< tetracarboxylic dianhydride >

X ₁ Is a 4-valent organic group derived from a tetracarboxylic acid derivative, and the structure thereof is not particularly limited. In addition, X in the polyimide precursor ₁ The polymer may be one kind of the same polymer or two or more kinds of the polymer may be mixed and present, depending on the degree of the properties required for the solubility of the polymer in a solvent, the coatability of a liquid crystal aligning agent, the alignment property of liquid crystal when a liquid crystal alignment film is formed, the voltage holding ratio, the accumulated charges, and the like.

If X is to be represented ₁ Specific examples of (4) include the structures of the formulae (X-1) to (X-46) described in items 13 to 14 of International patent publication No. 2015/119168.

Preferred X is shown below ₁ The present invention is not limited to the structure of (1).

[ solution 14]

[ solution 15]

Among the above structures, (A-1) and (A-2) are particularly preferable from the viewpoint of photo-alignment properties; from the viewpoint of further increasing the relaxation rate of the accumulated charge, (a-4); from the viewpoint of further improving the liquid crystal alignment properties and the relaxation rate of the accumulated charges, (A-15) to (A-17) are particularly preferable.

< Polymer (other structural Unit >

The polyimide precursor containing the structural unit represented by formula (6) may contain at least one selected from the structural unit represented by formula (7) below and a polyimide which is an imide compound thereof, within a range not impairing the effects of the present invention.

[ solution 16]

In the formula (7), X ₂ Is a 4-valent organic radical from a tetracarboxylic acid derivative; y is ₂ Is a 2-valent organic group derived from a diamine not containing the structure of formula (1); r ₅ With R of the above formula (6) ₄ The same definition as above, represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; r ₆ Represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. In addition, two R are preferred ₆ At least one of which is a hydrogen atom.

With respect to X ₂ Specific examples of (3) include preferred examples, and X of the formula (6) ₁ The structures shown in the examples are the same. In addition, Y in the polyimide precursor ₂ Is a 2-valent organic group derived from a diamine not containing the structure of formula (1), and the structure thereof is not particularly limited. In addition, Y ₂ The polymer may be one kind or two or more kinds may be mixed in the same polymer, which is appropriately selected depending on the degree of properties required for the solubility of the polymer in a solvent, the coatability of a liquid crystal aligning agent, the alignment property of liquid crystal when a liquid crystal alignment film is formed, the voltage holding ratio, the accumulated charges, and the like.

If Y is to be represented ₂ Specific examples of (3) include: the structure of formula (2) described in item 4 of International publication No. 2015/119168, and the structures of formulae (Y-1) to (Y-97), (Y-101) to (Y-118) described in items 8 to 12; a 2-valent organic group obtained by removing two amino groups from formula (2) described in section 6 of International publication No. 2013/008906; international laid-open publication No. 2015/122413, 8A 2-valent organic group obtained by removing two amino groups from the formula (1); a structure of formula (3) described in item 8 of International publication No. 2015/060360; a 2-valent organic group obtained by removing two amino groups from the formula (1) described in section 8 of Japanese laid-open patent publication No. 2012-173514; a 2-valent organic group obtained by removing two amino groups from the formulae (A) to (F) described in section 9 of International publication No. 2010-050523, and the like.

Preferred Y is shown below ₂ The present invention is not limited to the structure of (1).

[ solution 17]

[ solution 18]

[ solution 19]

[ solution 20]

Among the above structures, (B-28), (B-29), etc. are particularly preferable from the viewpoint of further improving the film hardness; from the viewpoint of further improving the liquid crystal alignment properties, (B-1) to (B-3) are particularly preferable; from the viewpoint of further increasing the relaxation rate of the accumulated charge, (B-14) to (B-18), and (B-27) are particularly preferable; from the viewpoint of further improving the voltage holding ratio, (B-26) and the like are particularly preferable.

When the polyimide precursor containing the structural unit represented by formula (6) contains the structural unit represented by formula (7) together, the structural unit represented by formula (6) is preferably 5 to 80 mol%, more preferably 10 to 50 mol%, based on the total of formula (6) and formula (7).

Examples of the polyimide having a 2-valent group represented by the formula (1) in the main chain include polyimides obtained by ring-closing the above polyimide precursor. In this polyimide, the ring-closure ratio of amic acid groups (also referred to as imidization ratio) does not need to be constant at 100%, and can be arbitrarily adjusted depending on the application or purpose.

< component B >

The polymer of the component (B) contained in the composition for forming a free-radical-generating film of the present invention is preferably a polymer obtained using a diamine. Specific examples thereof include polyamic acids, polyamic acid esters, polyimides, polyureas, polyamides, and the like, but from the viewpoint of being used as a composition for forming a radical generating film, more preferred are: at least one selected from the group consisting of a polyimide precursor containing only the structural unit represented by the formula (7) in the structural unit represented by the formula (6) and the structural unit represented by the formula (7), and a polyimide which is an imide compound thereof. The preferable tetracarboxylic dianhydride and diamine are the same as those exemplified in the above formula (7).

In the composition for forming a radical generating film as a liquid crystal aligning agent of the present invention, it is preferable that the polymer of the component (a) and the polymer of the component (B) do not contain a vertical aligning group for vertically aligning a liquid crystal.

In addition, in the case where the above-mentioned radical generating film is composed of a polymer containing an organic group which initiates radical polymerization, the radical generating film-forming composition used in the present invention may contain other polymers than the polymer containing an organic group which initiates radical polymerization. In this case, the content of the other polymer 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 radical generating film forming composition is preferably 5000 to 1000000, more preferably 10000 to 150000, in terms of the weight average molecular weight measured by GPC (Gel Permeation Chromatography) method, in consideration of the strength of the radical generating film obtained by applying the radical generating film forming composition, the workability at the time of forming a coating film, the uniformity of the coating film, and the like.

The radical generating film-forming composition may contain an organic solvent which dissolves or disperses the polymer component, other contained components used as needed. Such an organic solvent is not particularly limited, and examples thereof include the organic solvents exemplified in the synthesis of the polyamic acid. Among them, from the viewpoint of solubility, N-methyl-2-pyrrolidone, γ -butyrolactone, N-ethyl-2-pyrrolidone, 1, 3-dimethyl-2-imidazolidinone, 3-methoxy-N, N-dimethylpropionamide, and the like are preferable. Particularly, N-methyl-2-pyrrolidone or N-ethyl-2-pyrrolidone is preferable, and a mixed solvent of two or more kinds may be used.

Further, it is preferable to use a solvent for improving the uniformity or smoothness of the coating film in combination with an organic solvent having high solubility in the components contained in the radical generating film forming composition.

Examples of the solvent for improving the uniformity or smoothness of the coating film include isopropyl alcohol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol acetate, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol t-butyl ether, dipropylene glycol monomethyl ether, 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, ethylene glycol monomethyl ether, ethylene glycol methyl ether acetate, ethylene glycol monoethyl ether, propylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoacetate, ethylene glycol monomethyl ether, ethylene glycol monopropyl ether, ethylene glycol ether, propylene glycol monomethyl ether, propylene glycol ether, and mixtures thereof, Dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, n-hexane, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, isopropyl propionate, isobutyl ether, diisobutyl ether, butyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methyl cyclohexene, propyl ether, dihexyl ether, n-hexane, n-pentane, n-octane, diethyl ether, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, isopropyl propionate, butyl acetate, butyl propionate, butyl, Butyl 3-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, 2-ethyl-1-hexanol and the like. These solvents may be mixed in plural. When these solvents are used, the amount of the solvent is preferably 5 to 80% by mass, more preferably 20 to 60% by mass, based on the total amount of the solvent contained in the liquid crystal aligning agent.

The radical generating film-forming composition of the present invention may further contain components other than the polymer component and the organic solvent. Examples of such additional components include an adhesion promoter for improving the adhesion between the radical generating film and the substrate or the adhesion between the radical generating film and the sealant, a compound for improving the strength of the radical generating film (hereinafter, also referred to as a crosslinkable compound), a dielectric or conductive substance for adjusting the dielectric constant or resistance of the radical generating film, and the like.

The crosslinkable compound is preferably, from the viewpoints of less generation of AC afterimage and high effect of improving film strength: a compound having at least 1 group selected from the group consisting of an oxirane group, an oxetanyl group, a protective isocyanate group, a protective isothiocyanate group, an oxazoline ring structure-containing group, a meldrum acid structure-containing group, a cyclic carbonate group, and a group represented by the following formula (d); or a compound selected from the compounds represented by the following formula (e) (hereinafter, these are also collectively referred to as compound (C)).

[ solution 21]

(in the formula, R ₇₁ And R ₇₂ Each independently represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a group ". about.CH ₂ -OH ". And a symbol represents a bond. A represents an (m + n) -valent organic group having an aromatic ring. m represents an integer of 1 to 6, and n represents an integer of 0 to 4. R is ₇₃ Represents an alkyl group having 1 to 5 carbon atoms. )

Specific examples of the compound having an oxirane group include compounds having two or more oxirane groups such as a compound described in paragraph [0037] of Japanese patent laid-open No. 10-338880, and a compound having a triazine ring in the skeleton described in International publication No. WO 2017/170483. Among them, nitrogen atom-containing compounds such as N, N '-tetraglycidyl-m-xylylenediamine, 1, 3-bis (N, N-diglycidylaminomethyl) cyclohexane, N' -tetraglycidyl-4, 4 '-diaminodiphenylmethane, N' -tetraglycidyl-p-phenylenediamine, and compounds represented by the following formulae (r-1) to (r-3) are particularly preferable.

[ solution 22]

Specific examples of the oxetanyl group-containing compound include compounds having two or more oxetanyl groups described in paragraphs [0170] to [0175] of International patent publication No. 2011/132751.

Specific examples of the compound having a protective isocyanate group include compounds having two or more protective isocyanate groups described in paragraphs [0046] to [0047] of Japanese patent application laid-open No. 2014-224978, and compounds having 3 or more protective isocyanate groups described in paragraphs [0119] to [0120] of International publication laid-open No. 2015/141598. Among them, preferred are compounds represented by the following formulae (bi-1) to (bi-3).

[ solution 23]

Specific examples of the compound having a protective isothiocyanate group include compounds having two or more protective isothiocyanate groups as described in Japanese patent laid-open publication No. 2016-200798.

Specific examples of the compound having an oxazoline ring structure-containing group include compounds having two or more oxazoline structures described in paragraph [0115] of Japanese patent application laid-open No. 2007-286597.

Specific examples of the compound having a group having a Meldrum's acid structure include compounds having two or more Meldrum's acid structures described in International publication No. WO 2012/091088.

Specific examples of the compound having a cyclic carbonate group include those described in international publication No. WO 2011/155577.

R in the group represented by the above formula (d) ₇₁ 、R ₇₂ Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, and a propyl group.

Specific examples of the compound having a group represented by the above formula (d) include a compound having two or more groups represented by the above formula (d) described in International publication WO2015/072554, paragraph [0058] of Japanese patent laid-open No. 2016-. Among them, preferred are compounds represented by the following formulae (hd-1) to (hd-8).

[ solution 24]

Examples of the (m + n) -valent organic group having an aromatic ring in a of the formula (e) include (m + n) -valent aromatic hydrocarbon groups having 5 to 30 carbon atoms, (m + n) -valent organic groups in which the aromatic hydrocarbon groups having 5 to 30 carbon atoms are bonded directly or via a linking group, and (m + n) -valent groups having an aromatic heterocyclic ring. MakingExamples of the aromatic hydrocarbon include benzene and naphthalene. Examples of the aromatic heterocyclic ring include a pyrrole ring, an imidazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a quinoline ring, an isoquinoline ring, a carbazole ring, a pyridazine ring, a pyrazine ring, a benzimidazole ring (having a ring in Japanese: ベンズイミダゾール), a benzimidazole ring (having a ring in Japanese: ベンゾイミダゾール), an indole ring, a quinoxaline ring, and an acridine ring. Examples of the linking group include an alkylene group having 1 to 10 carbon atoms, a group obtained by removing one hydrogen atom from the alkylene group, and a cyclohexane ring having a valence of 2 or 3. Any hydrogen atom of the alkylene group may be substituted with an organic group such as an alkyl group having 1 to 6 carbon atoms, a fluorine atom, or a trifluoromethyl group. As R in the above formula (e) ₇₃ Examples of the alkyl group of (b) include a methyl group, an ethyl group, and a propyl group. Specific examples thereof include compounds described in International publication No. WO 2010/074269.

Preferable specific examples thereof include the following formulas (e-1) to (e-9).

[ solution 25]

The compound is an example of a crosslinkable compound, and is not limited thereto. For example, components other than those described above disclosed in International patent publication No. 2015/060357, page 53, paragraph [0105] to page 55, paragraph [0116], and the like can be mentioned. The crosslinkable compound contained in the radical generating film-forming composition of the present invention may be 1 kind, or two or more kinds may be combined.

The content of the crosslinkable compound in the radical generating film-forming composition of the present invention is preferably 0.5 to 20 parts by mass relative to 100 parts by mass of the polymer component contained in the radical generating film-forming composition, and more preferably 1 to 15 parts by mass from the viewpoint of exhibiting the intended effect by the crosslinking reaction and generating less AC residual image.

Examples of the adhesion promoter include: 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, N-aminopropyltriethoxysilane, N-aminopropyltrimethoxysilane, N-aminopropyltriethoxysilane, N-methyldimethoxysilane, N-aminopropyltrimethoxysilane, N-aminopropyltriethoxysilane, N-ethoxysilane, N-ethoxysilyltrimethylenetriamine, N-ethoxysilylpropyltriethylenetriamine, N-ethyltriamine, N-ethoxycarbonyl-3-ethoxysilane, N-ethoxysilane-N-propyltriethylenetriamine, N-methoxysilane-methyl-ethyl-silane, N-methyl-ethyl-methyl-3-ethyl-3-ethyl-methyl-ethyl-3-ethyl-methyl-ethyl-methyl-ethyl-3-ethyl-tri-ethyl-3-ethyl-tri-ethyl-methyl-tri-ethyl-3-ethyl-tri-ethyl-tri-ethyl-amine, or, 10-trimethoxysilyl-1, 4, 7-triazodecane, 10-triethoxysilyl-1, 4, 7-triazodecane, 9-trimethoxysilyl-3, 6-diazaspinonyl acetate, 9-triethoxysilyl-3, 6-diazaspinyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, N-bis (oxypropylene) -3-aminopropyl-trimethoxysilane, N-bis (oxyethylene) -3-triethoxysilane, N-bis (oxypropylene) -3-triethoxy-trimethoxysilane, N-bis (oxyethylene) -3-triethoxy-2-hydroxy-ethyl-methyl-ethyl-methyl-ethyl-3-ethyl-propyl-trimethoxysilane, N-ethyl-3-propyl-tert-propyl-trimethoxysilane, N-tert-propyl-tert-butyl-ethyl-butyl-methyl-ethyl-butyl-ethyl-butyl-phenyl-ethyl, Vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-vinyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris- (trimethoxysilylpropyl) isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, etc, Silane coupling agents such as 3-mercaptopropyltrimethoxysilane and 3-isocyanatopropyltriethoxysilane. When these silane coupling agents are used, the amount of the silane coupling agent is preferably 0.1 to 30 parts by mass, and more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal aligning agent, from the viewpoint of reducing the generation of AC residual images.

In addition to the above components, a dielectric or conductive substance for the purpose of changing electrical characteristics such as dielectric constant and conductivity of the radical generating film may be added to the radical generating film forming composition within a range not impairing the effects of the present invention.

Further, the radical generating film-forming composition of the present invention is a liquid crystal aligning agent having a radical generating ability. In the present specification, the liquid crystal alignment film obtained from the radical generating film-forming composition is particularly referred to as a radical generating film.

(radical generating film and liquid Crystal alignment film)

The radical generating film of the present embodiment is obtained by using the radical generating film forming composition. For example, the radical generating film-forming composition used in the present invention may be applied to a substrate, dried and sintered, and the obtained cured film may be used as it is as a radical generating film. The cured film may be subjected to rubbing, irradiation with polarized light, light of a specific wavelength, or the like, treatment with an ion beam, or the like, or irradiation with UV as an alignment film for PSA to a liquid crystal display element filled with liquid crystal.

Examples of the method of applying the radical generating film forming composition include spin coating, printing, ink jet, spray coating, roll coating, etc., but transfer methods are widely used industrially from the viewpoint of productivity, and are preferably used in the present invention.

The substrate to which the radical generating film-forming composition is applied is not particularly limited as long as it is a substrate having high transparency. Specific examples thereof include glass plates and plastic plates such as polycarbonate, poly (meth) acrylate, polyethersulfone, polyarylate, polyurethane, polysulfone, polyether, polyetherketone, trimethylpentene, polyolefin, polyethylene terephthalate, (meth) acrylonitrile, triacetyl cellulose, diacetyl cellulose, and cellulose acetate butyrate.

The drying step after the application of the radical generating film-forming composition is not necessarily essential, but when the time from the application to the firing is not the same for each substrate or when the firing is not immediately performed after the application, the drying step is preferably included. The drying is not particularly limited as long as the solvent is removed to such an extent that the shape of the coating film is not deformed by transportation of the substrate or the like. For example, the drying is performed for 0.5 to 30 minutes, preferably 1 to 5 minutes, on a hot plate at a temperature of 40 to 150 ℃, preferably 60 to 100 ℃.

The coating film formed by applying the radical generating film forming composition by the above method can be fired to form a cured film. In this case, the sintering temperature may be generally any temperature of 100 to 350 ℃, preferably 140 to 300 ℃, more preferably 150 to 230 ℃, and still more preferably 160 to 220 ℃. The firing time is usually 5 to 240 minutes. Preferably 10 to 90 minutes, and more preferably 20 to 90 minutes. The heating can be generally performed by a known method, for example, a hot plate, a hot air circulation oven, an IR (infrared) oven, a belt oven, or the like.

The thickness of the cured film can be selected as needed, but is preferably 5nm or more, more preferably 10nm or more, in which case the reliability of the liquid crystal display element is easily obtained. The thickness of the cured film is preferably 300nm or less, more preferably 150nm or less, and in this case, the power consumption of the liquid crystal display element does not become particularly large, which is preferable.

In the above manner, a substrate having a radical generating film can be obtained, but the radical generating film may be subjected to uniaxial orientation treatment. Examples of the method for performing the uniaxial orientation treatment include uniaxial orientation treatment by a photo-orientation method, a tilted deposition method, rubbing, a magnetic field, and the like.

In the case of performing the alignment treatment by performing the rubbing treatment in one direction, for example, the substrate is moved so that the rubbing cloth comes into contact with the film while rotating a rubbing roller around which the rubbing cloth is wound.

When the liquid crystal alignment property is imparted to the coating film by the photo-alignment treatment, ultraviolet rays and visible light including light having a wavelength of 150 to 800nm, for example, can be used as the radiation to be irradiated to the coating film. When the radiation is polarized light, the radiation may be linearly polarized light or partially polarized light. When the radiation used is linearly polarized light or partially polarized light, the irradiation may be performed from a direction perpendicular to the substrate surface, or from an oblique direction, or a combination thereof. When radiation of unpolarized light is irradiated, the irradiation direction is an oblique direction.

Examples of the light source that can be used include a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, and an excimer laser. The ultraviolet rays in a preferred wavelength range can be obtained by means of a light source in combination with, for example, a filter, a diffraction grating, or the like. The irradiation dose of the radiation is preferably 10 to 2000mJ/cm ² More preferably 30 to 1000mJ/cm ² 。

In addition, in order to improve the reactivity, the coating film may be irradiated with light while being heated. The temperature during heating is usually 30 to 250 ℃, preferably 40 to 200 ℃, and more preferably 50 to 150 ℃.

In the case of using ultraviolet rays including light having a wavelength of 150 to 800nm, the light-irradiated film obtained in the above-described step may be used as it is as a liquid crystal alignment film, or the light-irradiated film may be subjected to baking, washing with water or an organic solvent, or a combination thereof. The firing temperature at this time is preferably 80 to 300 ℃, more preferably 80 to 250 ℃. The firing time is preferably 5 to 200 minutes, and more preferably 10 to 100 minutes. The number of firing may be 1 or 2 or more. The photo-alignment process here corresponds to a process of light irradiation in a state of not being in contact with the liquid crystal layer.

The organic solvent used for the washing is not particularly limited, and specific examples thereof include: methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, cyclohexyl acetate, and the like.

In the liquid crystal cell according to the present invention, the radical generating film of the present invention can be used as a liquid crystal alignment film disposed on one substrate side; as the liquid crystal alignment film disposed on the other substrate side, a liquid crystal alignment film generally used can be used as the liquid crystal alignment film.

The liquid crystal alignment film of the present embodiment disposed on the other substrate side is obtained by the same method as the radical generating film except that a liquid crystal aligning agent generally used is used instead of the above-mentioned radical generating film forming composition.

In addition, as the substrate to which the radical generating film forming composition is applied and the substrate to which the liquid crystal aligning agent is applied, a substrate in which a transparent electrode for driving liquid crystal is formed on any of the above-mentioned substrates is preferable. Electrode patterns such as standard IPS comb-teeth electrodes and PSA fishbone electrodes, or projection patterns such as MVA, can be used for the substrates of IPS liquid crystal display elements.

In addition, in a high-functional element such as a TFT-type element, a structure in which an element such as a transistor is formed between an electrode for driving liquid crystal and a substrate can be used.

When a transmissive liquid crystal display element is desired to be obtained, a substrate as described above is generally used, but when a reflective liquid crystal display element is desired to be obtained, an opaque substrate such as a silicon wafer may be used as long as it is a single-sided substrate. In this case, a material such as aluminum that reflects light may be used for the electrodes formed on the substrate.

In the case of rubbing the liquid crystal alignment film on the substrate on which the comb-teeth electrodes are formed, the rubbing direction may be selected according to the electrical properties of the liquid crystal, but in the case of using a liquid crystal having positive dielectric anisotropy, the rubbing direction is preferably substantially the same as the extending direction of the comb-teeth electrodes.

(liquid Crystal cell)

The liquid crystal cell of the present invention is obtained by disposing a substrate (first substrate) having a liquid crystal alignment film and a substrate (second substrate) having a radical generating film formed on the substrate by the above-described method so that the radical generating film and the liquid crystal alignment film face each other, sandwiching a spacer, fixing the substrates with a sealant, injecting a liquid crystal composition containing a liquid crystal and a radical polymerizable compound, and sealing the substrates. In this case, the size of the spacer used is usually 1 to 30 μm, preferably 2 to 10 μm. Further, the alignment direction of the first substrate and the alignment direction of the second substrate are parallel to each other, whereby the liquid crystal display device can be used in an IPS mode or an FFS mode, and can be used in a twisted nematic mode if the liquid crystal display device is arranged so that the rubbing direction is perpendicular to each other.

Preferably, either one of the first substrate and the second substrate is a comb-tooth electrode substrate.

The alignment film formed on the first substrate may be a known liquid crystal alignment film, or may be any one of the radical generating films of the present invention, and may be appropriately selected according to the purpose.

The alignment film formed on the first substrate may be subjected to uniaxial alignment treatment.

Further, it is preferable that a liquid crystal alignment film for horizontal alignment subjected to uniaxial alignment treatment is formed on the first substrate.

The method for injecting the liquid crystal composition containing the liquid crystal and the radical polymerizable compound is not particularly limited, and examples thereof include: a vacuum method in which the inside of the prepared liquid crystal cell is depressurized and then a mixture containing a liquid crystal and a polymerizable compound is injected; a dropping method in which a mixture containing a liquid crystal and a polymerizable compound is dropped and then sealed, and the like.

< liquid Crystal composition containing liquid Crystal and radically polymerizable Compound >

In the production of the liquid crystal display element of the present invention, the polymerizable compound used together with the liquid crystal is not particularly limited as long as it is a radical polymerizable compound, and is, for example, a compound having one or two or more polymerizable reactive groups in one molecule. Preferably, the compound has one polymerizable reactive group in one molecule (hereinafter, sometimes referred to as "a compound having a polymerizable group having one functionality" or "a compound having a polymerizable group having one functionality", etc.). The polymerizable reactive group is preferably a radical polymerizable reactive group, such as a vinyl bond.

At least one of the radical polymerizable compounds is preferably a compound having one polymerizable reactive group in one molecule, that is, a compound having a monofunctional radical polymerizable group, which is compatible with liquid crystal.

The polymerizable group of the radical polymerizable compound is preferably a polymerizable group having a structure selected from the following groups.

[ solution 26]

(wherein R represents a site bonded to a portion of the compound molecule other than the polymerizable reactive group; R ^b Represents a linear alkyl group having 2 to 8 carbon atoms, E represents a single bond, -O-, -NR _c -, -S-, a bonding group in an ester bond and an amide bond. R _c Represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms).

In the liquid crystal composition containing a liquid crystal and a radical polymerizable compound, the radical polymerizable compound preferably satisfies: the Tg of a polymer obtained by polymerizing the radically polymerizable compound is 100 ℃ or lower.

The compound having a monofunctional radical polymerizable group is a compound having a reactive group capable of radical polymerization in the presence of an organic radical, and examples thereof include: methacrylate monomers such as t-butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, lauryl methacrylate, and n-octyl methacrylate; acrylate monomers such as t-butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, benzyl acrylate, lauryl acrylate, and n-octyl acrylate; styrene, vinyl monomers such as styrene derivatives (e.g., o-, m-, p-methoxystyrene, o-, m-, p-t-butoxystyrene, o-, m-, p-chloromethylstyrene, 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 isopropenyl ketone, etc.), N-vinyl compounds (e.g., N-vinylpyrrolidone, N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, etc.), (meth) acrylic acid derivatives (e.g., acrylonitrile, methacrylonitrile, acrylamide, isopropylacrylamide, methacrylamide, etc.), vinyl halides (e.g., vinyl chloride, vinylidene chloride, tetrachloroethylene, hexachloropropene, vinyl fluoride, etc.), however, the present invention is not limited to these examples. These various radically polymerizable monomers may be used alone or in combination of two or more. These are preferably compatible with liquid crystals.

The radical polymerizable compound is also preferably a compound represented by the following formula (a).

[ solution 27]

(in the formula (A), R ^a And R ^b Each independently represents a linear alkyl group having 2 to 8 carbon atoms, and E represents a single bond, -O-, -NR _c -, -S-, ester bond, amide bond. In the text R _c Represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms).

The radical polymerizable compound represented by formula (a) is preferably a compound in which E is an ester bond (-C (═ O) -O-or-O-C (═ O) -) in the formula, and more preferably a compound having the following structure, from the viewpoint of ease of synthesis, compatibility with a liquid crystal, and polymerization reactivity, but is not particularly limited.

[ solution 28]

(in the formulae (A-1) and (A-2), R ^a And R ^b Each independently representA C2-C8 linear alkyl group).

The content of the radical polymerizable compound in the liquid crystal composition is preferably 3% by mass or more, more preferably 5% by mass or more, preferably 50% by mass or less, more preferably 20% by mass or less, based on the total mass of the liquid crystal and the radical polymerizable compound.

The Tg of the polymer obtained by polymerizing the radically polymerizable compound is preferably 100 ℃ or lower.

The liquid crystal generally refers to a substance exhibiting both solid and liquid properties, and typical liquid crystal phases include nematic liquid crystal and smectic liquid crystal, and the liquid crystal usable in the present invention is not particularly limited. As an example, 4-pentyl-4' -cyanobiphenyl is given.

Next, energy sufficient to cause the radical polymerizable compound to undergo a polymerization reaction is applied to the liquid crystal cell into which the mixture (liquid crystal composition) containing the liquid crystal and the radical polymerizable compound is introduced. This can be performed, for example, by heating or UV irradiation, and the radical polymerizable compound is polymerized at this time, thereby exhibiting desired characteristics. Among them, UV irradiation is preferable in that it enables patterning of orientation and further enables a polymerization reaction to occur in a short time. When the liquid crystal composition is used in a twisted nematic mode, a chiral dopant may be introduced into a liquid crystal cell as needed, in addition to the liquid crystal composition.

In addition, heating may be performed during UV irradiation. The heating temperature in the UV irradiation is preferably within a temperature range in which the introduced liquid crystal exhibits liquid crystallinity, and is usually 40 ℃ or higher, and is preferably heated at a temperature lower than the temperature at which the liquid crystal becomes an isotropic phase.

Here, the UV irradiation wavelength in the UV irradiation is preferably selected to have the best reaction quantum yield of the polymerizable compound to be reacted, and the UV irradiation dose is usually 0.5 to 30J/cm ² Preferably 1 to 10J/cm ² The smaller the amount of UV irradiation, the more the reduction in reliability due to the destruction of the components constituting the liquid crystal display can be suppressed, and the reduction in UV irradiation time can be used to improve the productivityCadence and is therefore preferred.

In addition, the heating in the case of polymerizing the polymerizable compound by heating alone without UV irradiation is preferably performed in a temperature range from the temperature at which the polymerizable compound reacts to a temperature lower than the decomposition temperature of the liquid crystal. Specifically, the temperature is 100 ℃ to 150 ℃.

When energy sufficient to cause a polymerization reaction of the radical polymerizable compound is given, an electric field-free state in which no voltage is applied is preferable.

(liquid Crystal display element)

The liquid crystal display element can be manufactured using the liquid crystal cell obtained in the above manner.

For example, a reflective liquid crystal display element can be produced by providing the liquid crystal cell with a reflective electrode, a transparent electrode, a λ/4 plate, a polarizing film, a color filter layer, and the like as needed in a conventional manner.

In addition, a backlight, a polarizing plate, a λ/4 plate, a transparent electrode, a polarizing film, a color filter layer, and the like may be provided to the liquid crystal cell as needed in a conventional method, thereby producing a transmissive liquid crystal display element.

Fig. 1 is a schematic cross-sectional view showing an example of a liquid crystal display device of the present invention, and is an example of an IPS mode liquid crystal display device.

In the liquid crystal display element 1 illustrated in fig. 1, a liquid crystal composition 3 is sandwiched between a comb-shaped electrode substrate 2 provided with a radical generating film 2c and a counter substrate 4 provided with a liquid crystal alignment film 4 a. The comb-tooth electrode substrate 2 includes: a substrate 2a, a plurality of linear electrodes 2b formed on the substrate 2a and arranged in a comb-tooth shape, and a radical generating film 2c formed on the substrate 2a so as to cover the linear electrodes 2 b. The counter substrate 4 includes: a substrate 4b, and a liquid crystal alignment film 4a formed on the substrate 4 b.

In the liquid crystal display element 1, when a voltage is applied to the linear electrodes 2b, an electric field is generated between the linear electrodes 2b as indicated by the lines of electric force L.

Fig. 2 is a schematic cross-sectional view showing another example of the liquid crystal display element of the present invention, and is an example of an FFS mode liquid crystal display element.

In the liquid crystal display element 1 illustrated in fig. 2, a liquid crystal composition 3 is sandwiched between a comb-shaped electrode substrate 2 provided with a radical generating film 2h and a counter substrate 4 provided with a liquid crystal alignment film 4 a. The comb-shaped electrode substrate 2 includes: a substrate 2d, a surface electrode 2e formed on the substrate 2d, an insulating film 2f formed on the surface electrode 2e, a plurality of linear electrodes 2g formed on the insulating film 2f and arranged in a comb-tooth shape, and a radical generating film 2h formed on the insulating film 2f so as to cover the linear electrodes 2 g. The counter substrate 4 includes: a substrate 4b, and a liquid crystal alignment film 4a formed on the substrate 4 b.

In the liquid crystal display element 1, when a voltage is applied to the surface electrode 2e and the linear electrode 2g, an electric field is generated between the surface electrode 2e and the linear electrode 2g as indicated by the electric line of force L.

Examples

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. The labeling of the compound used in the preparation of the polymer polymerization and film-forming composition, and the method of evaluating the properties are as follows.

[ solution 29]

[ solution 30]

NMP: n-methyl-2-pyrrolidone,

BCS: butyl cellosolve

< measurement of viscosity >

The polyamic acid solution was measured for viscosity at 25 ℃ in a sample volume of 1.1mL using an E-type viscometer TVE-22H (manufactured by Toyobo industries Co., Ltd.) and a Cone Rotor (Cone Rotor) TE-1(1 ℃ 34', R24).

< measurement of molecular weight >

The molecular weight was measured by a normal temperature GPC (gel permeation chromatography) apparatus, and the number average molecular weight (Mn) and the weight average molecular weight (Mw) were calculated as values converted from polyethylene glycol and polyethylene oxide.

GPC apparatus: GPC-101 (manufactured by Showa Denko K.K.), column: GPC KD-803 and GPC KD-805 (manufactured by SHOWA DENKO K.K.) were connected in series, and the column temperature: 50 ℃ and eluent: n, N-dimethylformamide (as additive, lithium bromide monohydrate (LiBr. H) ₂ O) 30mmol/L, phosphoric acid anhydrous crystals (orthophosphoric acid) 30mmol/L, Tetrahydrofuran (THF) 10mL/L), flow rate: 1.0 mL/min

Calibration curve preparation standard sample: TSK standard polyethylene oxides (molecular weight: 900000, 150000, 100000 and 30000, manufactured by Tosoh corporation) and polyethylene glycols (molecular weight: 12000, 4000 and 1000, manufactured by Polymer Laboratories, Inc.).

< measurement of imidization Rate >

20mg of the polyimide powder was put into an NMR sample tube (manufactured by Kabushiki Kaisha Seiki, NMR Sampling tube Standard)

) To this solution, 0.53mL of deuterated dimethyl sulfoxide (DMSO-d) was added ₆ 0.05 mass% TMS (tetramethylsilane) mixture) was added to the mixture, and ultrasonic waves were applied thereto to completely dissolve the TMS (tetramethylsilane) mixture. The 500MHz proton NMR of the solution was measured by a measuring apparatus (JNW-ECA 500, manufactured by DATUM corporation, Japan).

The imidization ratio is determined using protons from a structure that does not change before and after imidization as reference protons, and is determined by the following equation using the peak integral value of the protons and the peak integral value of the protons derived from NH present in the amide group at around 9.5 to 10.0 ppm.

Imidization ratio (%) - (1-. alpha.x/y). times.100

In the formula, x is a peak integrated value of NH from an amide group, y is a peak integrated value of a reference proton, and α is a number ratio of the reference proton to NH proton of 1 amide group in the case of a polyamic acid (imidization ratio of 0%).

< Synthesis of Compound DA-5 >

[ solution 31]

(first step)

Tetrahydrofuran (120g), 2-hydroxy-4 '- (2-hydroxyethoxy) -2-methylpropiophenone (28.4g, 126mmol), 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide (28.0g, 181mmol) and N, N-dimethylaminopyridine (0.735g, 6.02mmol) were added to 4, 4' -dinitro- [1,1 '-biphenyl ] -2, 2' -dicarboxylic acid (20.0g, 60.2mmol), and the mixture was stirred at room temperature overnight. After the reaction was completed, liquid-separation extraction was performed twice with water/chloroform, and the obtained organic phase was concentrated to obtain a syrup-like tea oil. This was purified by column chromatography in a mixed solvent of ethyl acetate/hexane 3/1 (volume ratio). The fractions obtained were concentrated to give a yellow clear oil which was allowed to stand further to precipitate white crystals from the oil. The precipitated crystals were washed with a slurry of a mixed solvent of ethyl acetate/hexane 3/1 (volume ratio), filtered, and dried to obtain compound [1] (yield: 29.8g, 40.0mmol, yield 67%).

¹ H-NMR(500MHz)in DMSO-d ₆ ：8.57(d，J＝2.5Hz，2H)，8.37(dd，J＝8.5Hz，2.5Hz，2H)，8.18(d，J＝9.0Hz，4H)，7.55(d，J＝8.5Hz，2H)，6.85(d，J＝9.0Hz，4H)，5.631(s，2H)，4.39-4.35(m，4H)，4.02-3.99(m，2H)，3.96-3.94(m，2H)，1.40(s，12H)。

(second Process)

Tetrahydrofuran (240g) was added to the compound [1] (29.8g, 40.0mmol) obtained in the first step, nitrogen substitution was performed, then 3% platinum carbon (hydrous product) (2.38g) was added thereto and nitrogen substitution was further performed, a tedlar hydrogen sampling bag (tedlar bag) was attached, and stirring was performed at room temperature for about 17 hours. After completion of the reaction, platinum carbon was removed by a membrane filter, and then the mixture was concentrated and dried to obtain DA-5 (yield: 27.4g, 40.0mmol, yield quant).

¹ H-NMR(500MHz)in DMSO-d ₆ ：8.20(dd，J＝7.1Hz，1.9Hz，4H)，6.99(d，J＝2.5Hz，2H)，6.92(dd，J＝7.3Hz，1.9Hz，4H)，6.80(d，J＝8.2Hz，2H)，6.67(dd，J＝8.2Hz，2.5Hz，2H)，5.64(s，2H)，5.24(s，4H)，4.22(t，J＝4.5Hz，4H)，4.00(br，4H)，1.39(s，12H)。

< Synthesis of Polyamic acid and polyimide >

< Synthesis example 1> polymerization of TC-1/DA-1, DA-2(50) Polyamic acid (PAA-1)

DA-1(1.62 g: 15.0mmol), DA-2(3.66 g: 15.0mmol) and NMP (55.4g) were weighed into a 100mL 4-neck flask equipped with a mechanical stirrer and a nitrogen introduction tube, and dissolved by stirring for a while, TC-1(6.25 g: 27.9mmol) and NMP (10.0g) were added, and the mixture was reacted at 40 ℃ for 6 hours under a nitrogen atmosphere, whereby a polyamic acid solution (PAA-1) having a solid content concentration of 15 mass% was obtained. The viscosity was 390 mPas, and the weight-average molecular weight was about 32100.

< Synthesis example 2> polymerization of TC-3/DA-3(100) Polyamic acid (PAA-2)

DA-3(5.73 g: 20.0mmol) and NMP (61.8g) were weighed into a 100mL 4-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube, stirred for a while to dissolve them, TC-3(4.06 g: 18.6mmol) and NMP (10.0g) were added, and the mixture was reacted at 23 ℃ for 6 hours under a nitrogen atmosphere to obtain a polyamic acid solution (PAA-2) having a solid content concentration of 12 mass%. The viscosity was 240 mPas and the weight average molecular weight was about 25900.

< Synthesis example 3> polymerization of TC-2, TC-4(50)/DA-1, DA-4(50) Polyamic acid (PAA-3)

DA-1(1.08 g: 10.0mmol), DA-4(3.30 g: 10.0mmol) and NMP (32.9g) were measured in a50 mL-volume 4-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube, and after stirring for a while under a nitrogen atmosphere to dissolve them, TC-4(2.50 g: 10.0mmol) was added, and after 6 hours of reaction at 40 ℃ under a nitrogen atmosphere, TC-2(1.88 g: 9.6mmol) and NMP (2.1g) were added, and after 12 hours of reaction at 40 ℃ under a nitrogen atmosphere, a polyamic acid solution (PAA-3) having a solid content concentration of 20 mass% was obtained. The viscosity was 980 mPas and the weight-average molecular weight was about 35900.

< Synthesis example 4> Synthesis of TC-2, TC-4(50)/DA-1, DA-4(50) soluble polyimide (SPI-1)

In a 100mL eggplant-shaped flask equipped with a nitrogen introduction tube, an air-cooling tube, and a stirrer, the polyamic acid solution (PAA-3) (30.0g) obtained in Synthesis example 3 was weighed, NMP (70.0g), acetic anhydride (3.14 g: 30.9mmol), and pyridine (1.62 g: 20.6mmol) were added, and the mixture was stirred at room temperature for 30 minutes under a nitrogen atmosphere, and then stirred at 50 ℃ for 3 hours. After completion of the reaction, the reaction solution was returned to room temperature, and the mixture was slowly poured into methanol (300mL) cooled to 10 ℃ to precipitate a solid, which was then stirred for 10 minutes. The obtained solid was collected by filtration, and the obtained solid was further washed with methanol (100mL) under stirring for 10 minutes twice in total, and dried in a vacuum drying oven at 80 ℃ for 6 hours to obtain the objective polyimide powder (SPI-1). The imidization rate was 62%.

< Synthesis examples 5> polymerization of TC-2, TC-4(50)/DA-4(100) Polyamic acid (PAA-4)

DA-4(6.61 g: 20.0mmol) and NMP (34.1g) were measured in a50 mL-volume 4-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube, and after stirring for a while under a nitrogen atmosphere to dissolve them, TC-4(2.50 g: 10.0mmol) was added and reacted at 40 ℃ for 6 hours under a nitrogen atmosphere, TC-2(1.92 g: 9.8mmol) and NMP (10.0g) were added and reacted at 40 ℃ for 12 hours under a nitrogen atmosphere, thereby obtaining a polyamic acid solution (PAA-4) having a solid content concentration of 20 mass%. The viscosity was 1120 mPas, and the weight-average molecular weight was about 38400.

< Synthesis example 6> Synthesis of TC-2, TC-4(50)/DA-4(100) soluble polyimide (SPI-2)

In a 100mL eggplant-shaped flask equipped with a nitrogen introduction tube, an air cooling tube and a stirrer, 30.0g of the polyamic acid solution (PAA-4) (30.0g) obtained in Synthesis example 5 was weighed, NMP (70.0g), acetic anhydride (3.33 g: 32.7mmol) and pyridine (1.72 g: 21.8mmol) were added, and the mixture was stirred at room temperature for 30 minutes under a nitrogen atmosphere and then at 50 ℃ for 3 hours. After completion of the reaction, the reaction solution was returned to room temperature, and the mixture was slowly poured into methanol (300mL) cooled to 10 ℃ to precipitate a solid, which was then stirred for 10 minutes. The obtained solid was collected by filtration, and the obtained solid was further washed with methanol (100mL) under stirring for 10 minutes twice in total, and dried in a vacuum drying oven at 80 ℃ for 6 hours to obtain the objective polyimide powder (SPI-2). The imidization rate was 59%.

< Synthesis example 7> polymerization of TC-1/DA-2, DA-4(50) Polyamic acid (PAA-5)

DA-2(1.57 g: 7.00mmol), DA-4(4.79 g: 7.00mmol) and NMP (42.60g) were weighed into a50 mL-capacity 4-neck flask equipped with a mechanical stirrer and a nitrogen introduction tube, and dissolved by stirring for a while, TC-1(2.92 g: 13.02mmol) and NMP (10.0g) were added, and the mixture was reacted at 40 ℃ for 6 hours under a nitrogen atmosphere, whereby a polyamic acid solution (PAA-5) was obtained. The viscosity was 440 mPas and the weight-average molecular weight was about 32600.

< Synthesis example 8> Synthesis of TC-1/DA-2, DA-4(50) soluble polyimide (SPI-3)

In a 100mL eggplant-shaped flask equipped with a nitrogen introduction tube, an air-cooling tube, and a stirrer, 30.0g of the polyamic acid solution (PAA-5) (30.0) obtained in Synthesis example 7 was weighed, NMP (45.0g), acetic anhydride (1.85 g: 18.0mmol), and pyridine (0.95 g: 12.0mmol) were added, and the mixture was stirred at room temperature for 30 minutes under a nitrogen atmosphere and then at 50 ℃ for 3 hours. After completion of the reaction, the reaction solution was returned to room temperature, and the mixture was slowly poured into methanol (300mL) cooled to 10 ℃ to precipitate a solid, which was then stirred for 10 minutes. The obtained solid was collected by filtration, and the obtained solid was further washed with methanol (100mL) under stirring for 10 minutes twice in total and dried in a vacuum drying oven at 80 ℃ for 6 hours to obtain the objective polyimide powder (SPI-3). The imidization rate was 72%.

< Synthesis example 9> polymerization of TC-1/DA-2, DA-5(50) Polyamic acid (PAA-6)

DA-2(2.44 g: 10.00mmol), DA-5(6.85 g: 10.00mmol) and NMP (66.0g) were weighed into a50 mL-volume 4-neck flask equipped with a mechanical stirrer and a nitrogen introduction tube, and dissolved by stirring for a while, TC-1(4.12 g: 18.38mmol) and NMP (10.0g) were added and reacted at 40 ℃ for 6 hours under a nitrogen atmosphere, whereby a polyamic acid solution (PAA-6) having a solid content concentration of 15 mass% was obtained. The viscosity was 380 mPas, and the weight-average molecular weight was about 29600.

< Synthesis example 10> Synthesis of TC-1/DA-2, DA-5(50) soluble polyimide (SPI-4)

In a 100mL eggplant-shaped flask equipped with a nitrogen introduction tube, an air cooling tube and a stirrer, the polyamic acid solution (PAA-6) (30.0g) obtained in Synthesis example 9 was weighed, NMP (45.0g), acetic anhydride (2.42 g: 23.7mmol) and pyridine (1.25 g: 15.8mmol) were added, and the mixture was stirred at room temperature for 30 minutes under a nitrogen atmosphere and then at 50 ℃ for 3 hours. After completion of the reaction, the reaction solution was returned to room temperature, and the mixture was slowly poured into methanol (300mL) cooled to 10 ℃ to precipitate a solid, which was then stirred for 10 minutes. The obtained solid was collected by filtration, and the obtained solid was further washed with methanol (100mL) under stirring for 10 minutes twice in total and dried in a vacuum drying oven at 80 ℃ for 6 hours to obtain the objective polyimide powder (SPI-4). The imidization rate was 68%.

(example 1)

Preparation of highly anchored liquid crystal aligning agent (also called strong anchored liquid crystal aligning agent) AL-1

A50 mL Erlenmeyer flask equipped with a stirrer was charged with the polyamic acid solution (PAA-1) (20.0g) obtained in Synthesis example 1, and NMP (15.0g), BCS (15.0g) and Add-1(0.15g) were added thereto and stirred at room temperature for 30 minutes to prepare a liquid crystal aligning agent AL-1.

(example 2)

Preparation of highly anchored liquid crystal aligning agent AL-2

A50 mL Erlenmeyer flask equipped with a stirrer was charged with the polyamic acid solution (PAA-2) (20.0g) obtained in Synthesis example 2, and NMP (8.0g), BCS (12.0g) and Add-2(0.12g) were added thereto and stirred at room temperature for 30 minutes to prepare a liquid crystal aligning agent AL-2.

Examples 3 to 6 preparation of compositions AL-3 to AL-6 for Forming free-radical-generating film

In a two-necked eggplant-shaped flask equipped with a nitrogen inlet tube and a stirrer, the polyimide powder (SPI-1) (2.0g) obtained in synthesis example 4 was weighed out, and NMP (18.0g) was added thereto and dissolved by stirring at 40 ℃ for 6 hours. After confirming complete dissolution, NMP (3.3g), BCS (10.0g) and Add-2(0.10g) were added and stirred at room temperature for 30 minutes, thereby obtaining a radical generating film forming composition AL-3.

Further, preparation was carried out in the same manner as for the above-mentioned AL-3 except that SPI-2 to SPI-4 were used in place of SPI-1, and that Add-2 was used for SPI-2 and Add-1 was used for SPI-3 and SPI-4, to obtain radical-generating film-forming compositions AL-4 to AL-6, respectively.

Example 7 preparation of free radical generating film Forming composition AL-7

To a 40mL sample bottle equipped with a stirrer were added the strongly anchored liquid crystal aligning agent AL-1(5.0g) prepared in example 1 and AL-3(5.0g) prepared in example 3, and stirred at room temperature for 30 minutes, thereby preparing a radical generating film forming composition AL-7 of the present invention.

Example 8 preparation of free radical generating film Forming composition AL-8

To a 40mL sample bottle equipped with a stirrer were added the strongly anchored liquid crystal aligning agent AL-1(5.0g) prepared in example 1 and AL-4(5.0g) prepared in example 4, and stirred at room temperature for 30 minutes, thereby preparing the radical generating film forming composition AL-8 of the present invention.

Example 9 preparation of radical generating film Forming composition AL-9

To a 40mL sample bottle equipped with a stirrer were added the strongly anchored liquid crystal aligning agent AL-1(5.0g) prepared in example 1 and AL-5(5.0g) prepared in example 5, and stirred at room temperature for 30 minutes, thereby preparing the radical generating film forming composition AL-9 of the present invention.

Example 10 preparation of free radical generating film Forming composition AL-10

To a 40mL sample bottle equipped with a stirrer were added the strongly anchored liquid crystal aligning agent AL-1(5.0g) prepared in example 1 and AL-6(5.0g) prepared in example 6, and stirred at room temperature for 30 minutes, thereby preparing the radical generating film forming composition AL-10 of the present invention.

Example 11 preparation of radical generating film Forming composition AL-11

To a 40mL sample bottle equipped with a stirrer were added the strongly anchored liquid crystal aligning agent AL-2(5.0g) prepared in example 2 and AL-3(5.0g) prepared in example 3, and the mixture was stirred at room temperature for 30 minutes, thereby preparing a radical generating film forming composition AL-11 of the present invention.

Example 12 preparation of free radical generating film Forming composition AL-12

To a 40mL sample bottle equipped with a stirrer were added the strongly anchored liquid crystal aligning agent AL-2(5.0g) prepared in example 2 and AL-4(5.0g) prepared in example 4, and stirred at room temperature for 30 minutes, thereby preparing the radical generating film forming composition AL-12 of the present invention.

< preparation of liquid Crystal cell >

A method for manufacturing a liquid crystal cell for evaluating liquid crystal alignment properties is described below.

First, a substrate with electrodes is prepared. The substrate was a glass substrate having a size of 30mm × 35mm and a thickness of 0.7 mm. An IZO electrode having a pattern of a full-surface shape (japanese: ベタ) constituting a counter electrode is formed as a first layer on the substrate. A SiN (silicon nitride) film formed by a CVD (chemical vapor deposition) method is formed as a second layer on the counter electrode of the first layer. The SiN film of the second layer has a film thickness of 500nm and functions as an interlayer insulating film. A comb-shaped pixel electrode formed by patterning an IZO film is disposed as a third layer on the SiN film of the second layer, and two pixels, i.e., a first pixel and a second pixel, are formed. The size of each pixel is 10mm long and about 5mm wide. 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.

The pixel electrode of the third layer has a comb-tooth shape in which a plurality of electrode elements each having a width of 3 μm and each having a central portion bent at an inner angle of 160 ° are arranged in parallel at intervals of 6 μm, and one pixel has a first region and a second region with a line connecting the bent portions of the plurality of electrode elements as a boundary.

When the first region and the second region of each pixel are compared, it is found that the formation directions of the electrode elements constituting the pixel electrodes are different. That is, when the alignment direction of the liquid crystal alignment film described later is set as a reference, the electrode element of the pixel electrode is formed so as to be at an angle of +80 ° (clockwise) in the first region of the pixel, and the electrode element of the pixel electrode is formed so as to be at an angle of-80 ° (counterclockwise) in the second region of the pixel. That is, in the first region and the second region of each pixel, the directions of the rotational motion (in-plane switching) of the liquid crystal in the substrate plane, which is induced by applying a voltage between the pixel electrode and the counter electrode, are opposite to each other. Hereinafter referred to as an FFS substrate (first substrate).

Then, will pass the aboveThe resultant composition for forming a radical-generating film, AL-3 to AL12, liquid crystal aligning agent AL-1, and SE-6414 (manufactured by Nissan chemical Co., Ltd.) as a liquid crystal aligning agent for horizontal alignment were filtered through a filter having a pore diameter of 1.0 μm, and then coated and formed by spin coating on the prepared first substrate and a glass substrate (hereinafter referred to as a second substrate) having an ITO film formed on the back surface thereof and a columnar spacer having a height of 4.0 μm as a counter substrate. Then, the film was dried on a hot plate at 80 ℃ for 80 minutes and then baked at 230 ℃ for 20 minutes to obtain a coating film having a film thickness of 100 nm. In the polyimide film on the first substrate side, alignment treatment is performed in a direction along the comb teeth, and in the polyimide film on the second substrate side, alignment treatment is performed in a direction perpendicular to the comb teeth electrode. Furthermore, in SE-6414, AL-3, AL-4, AL-11, AL-12, orientation treatment was performed by rubbing treatment, and in AL-1, AL-5, AL-6, AL-7, AL-8, AL-9, AL-10, orientation treatment was performed by photo-orientation. The rubbing treatment was carried out using rayon cloth YA-20R manufactured by Gikka chemical, under conditions of a roll diameter of 12mm, a rotational speed of 700rpm, a table transport speed of 30mm/s and an indentation pressure of 0.4mm, and the radical generating film was carried out under conditions of a rotational speed of 300rpm, a table transport speed of 50mm/s and an indentation pressure of 0.2 mm. In addition all photo-alignment is performed by: using a UV exposure apparatus manufactured by Ushio motor co, an extinction ratio was set to be about 26: 1, linear polarization UV of 50 to 500mJ/cm based on a wavelength of 254nm ² Irradiating polarized UV with the irradiation amount between, and heating at 230 deg.C for 30 min; the alignment quality was compared under the most favorable conditions.

Thereafter, using the above-described two substrates, with respect to the display element as an object of the embodiment, AL-1 or SE-6414 was used on the first substrate side, and a radical generating film AL-7, AL-8, AL-9, AL-10, AL-11, AL-12 was provided on the second substrate side, and a display element made of a combination thereof was used; as the display elements to be compared, display elements using AL-1 or SE-6414 for two substrates and display elements made using a combination of the radical generating films AL-3, AL-4, AL-5, AL-6 on the first substrate side and AL-1 on the second substrate side were used. The alignment directions of the cells were combined in parallel, and the periphery was sealed with the liquid crystal injection port left, thereby producing a void cell having a cell gap of about 4 μm. In this empty cell, a liquid crystal (obtained by adding 3 mass% of an additive IC6 to MLC-3019 manufactured by Merck) was vacuum-injected at room temperature, and then the injection port was sealed to prepare an antiparallel aligned liquid crystal cell. The resulting liquid crystal cell constitutes an FFS mode liquid crystal display element. Thereafter, the obtained liquid crystal cell was heat-treated at 120 ℃ for 10 minutes, and irradiated with UV (UV lamp: FLR40SUV32/A-1) for 30 minutes using a UV-FL irradiation apparatus manufactured by TOSHIBA LIGHT & TECHNOLOGY Co., Ltd, in a state where no voltage was applied, to obtain a liquid crystal display element.

< evaluation of liquid Crystal alignment >

The polarizing plate was fixed in a state where the brightness of the liquid crystal cell was minimized by using a polarizing microscope, and the alignment state of the liquid crystal was observed by rotating the liquid crystal cell by 1 ° from this state. When unevenness, rough surface, or the like is not observed or is very slight, the evaluation is "good", and when the above is clearly observed, the evaluation is "poor".

In addition, a photodiode was mounted on the same polarizing microscope, connected to an electrometer through a current-voltage conversion amplifier, and the black luminance was measured by detecting the voltage under the condition that the luminance becomes minimum under the crossed nicols.

< measurement of V-T Curve and evaluation of Driving threshold Voltage and Brightness maximum Voltage >

The V-T curve was measured by arranging a white LED backlight and a luminance meter with their optical axes aligned, arranging a liquid crystal cell (liquid crystal display element) between them, to which a polarizing plate was attached so as to minimize luminance, applying a voltage up to 8V at intervals of 1V, and measuring the luminance at the voltage. The driving threshold voltage and the voltage value at which the luminance is maximum are estimated from the obtained V-T curve. In addition, the maximum transmittance was estimated by comparing the maximum transmission luminance in the V-T curve with the transmission luminance through the liquid crystal cell to which no voltage was applied when the parallel nicols were used set to 100%.

< determination of response time (Ton, Toff) >

Using the apparatus used in the measurement of the V-T curve described above, a luminance meter was connected to an oscilloscope, and the response speed (Ton) when a voltage reaching the maximum luminance was applied and the response speed (Toff) when the voltage returned to 0V were measured.

< contents of polymers >

[ Table 1]

< contents of liquid crystal aligning agent or radical generating film-forming composition >

[ Table 2]

< contents of liquid crystal cell of example >

The liquid crystal cell was constructed as shown in table 3 below.

[ Table 3]

< results >

[ Table 4]

Comparative example 1 is an example in which photo-oriented strong anchor alignment films are combined with each other, and comparative examples 2 and 3 are examples in which the constituent components of the radical generating film are separate components. Examples 13 to 16 are examples in which a strong anchor component and a radical generating component were mixed in a radical generating film. It is understood that the black brightness of examples 13 to 16 was substantially equivalent to the combination of the strong anchor alignment films of comparative example 1, and that the black brightness was also good, the transmittance was also greatly improved, and the retardation of the response time was suppressed as compared with comparative example 2 or comparative example 3. In particular, it is found that in the liquid crystal cells (examples 13 and 14) using the radical generating film component which was not photo-aligned, good alignment properties and black luminance were obtained, and good weak anchoring properties were obtained. On the other hand, it is understood that the black luminance and the transmittance are good in comparative example 3, but the black luminance is further improved and the response time is improved by mixing the strong anchor component (example 16) as compared with the single component.

Comparative example 4 is an example in which strong anchor alignment films for rubbing are combined with each other, and comparative examples 5 and 6 are examples when radical generating films of individual components that are not photo-aligned are used. In contrast, examples 17 and 18 are examples in which a strong anchor component for friction is mixed with a radical generating component. It is understood that the alignment properties and black luminance of examples 17 and 18 are all on the same level as SE-6414, the transmittance is improved, and the delay in response time is suppressed.

Therefore, it is found from these verification experiments that a liquid crystal display element capable of maintaining good alignment properties and achieving both improvement in transmittance and suppression of response time is obtained by using the radical generating film forming composition of the present invention in which a strong anchor component and a radical generating component are mixed.

Industrial applicability

By using the radical generating film forming composition of the present invention, a horizontal electric field liquid crystal display element capable of realizing good black display, high backlight transmittance, and high response speed can be provided. The liquid crystal display element obtained by the method of the present invention can be used as a liquid crystal display element of a transverse electric field driving method.

Description of the reference numerals

1 liquid crystal display element

2 comb electrode substrate

2a base material

2b wire electrode

2c free radical generating membranes

2d base material

2e face electrode

2f insulating film

2g wire electrode

2h free radical generating membranes

3 liquid crystal composition

4 opposite substrates

4a liquid crystal alignment film

4b base material

Claims

1. A composition for forming a radical generating film, comprising a component (A) which is a polymer having a structural unit represented by the following formula (1) in the main chain and a component (B) which is a polymer used as an alignment component of a liquid crystal aligning agent for driving a horizontal electric field,

in formula (1), A represents an organic group that initiates radical polymerization.

2. The radical generating film forming composition according to claim 1, wherein the polymer as the component (a) is at least one polymer selected from the group consisting of a polyimide precursor obtained using a diamine component comprising a diamine containing an organic group which initiates radical polymerization, a polyimide, a polyurea, and a polyamide.

3. The radical generating film forming composition according to claim 2, wherein the diamine containing an organic group which initiates radical polymerization is a diamine represented by the following formula (2),

in the formula (2), A ¹ And A ² Each represents a hydrogen atom or an organic group which initiates radical polymerization, wherein A ¹ And A ² At least one of which represents an organic group that initiates radical polymerization,

e represents a single bond, -O-, -C (CH) ₃ ) ₂ -、-NH-、-CO-、-NHCO-、-COO-、-(CH ₂ ) _m -、-SO ₂ A 2-valent organic group containing any combination thereof, m represents an integer of 1 to 8,

p represents an integer of 0 to 2; when p is 2, a plurality of A ² Each independently has the foregoing definitions; in addition, when p is 0, A ¹ Contains an organic group which initiates free radical polymerization.

4. The radical generating film forming composition according to any one of claims 1 to 3, wherein the radical polymerization initiating organic group is a group represented by the following formula (3),

----R ⁶ -R ⁷ -R ⁸ (3)

in the formula (3), the dotted line represents a bond to a benzene ring, 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 alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted with a fluorine atom, or any of-CH's of the alkylene groups ₂ -or-CF ₂ 1 or more of-are independently replaced or not replaced by a group selected from-CH- ═ CH-, a 2-valent carbocyclic ring and a 2-valent heterocyclic ring, and further, are replaced or not replaced by any of the groups mentioned below, i.e., -O-, -COO-, -OCO-, -NHCO-, -CONH-, or-NH-without being adjacent to each other,

R ⁸ is represented by a group selected from the formula [ X-1 ]]～[X-18]、[W]、[Y]、[Z]The introduction of formula (II)An organic group which is polymerized by free radicals,

formula [ X-1]～[X-18]Wherein represents a group represented by ⁷ Bonding site of (2), S ₁ And S ₂ Each independently represents-O-, -NR-, or-S-, wherein R 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 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms,

formula [ W ]]、[Y]、[Z]Wherein represents a group represented by ⁷ The bonding site of (3); s ³ Represents a single bond, -O-, -S-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-、-N(CH ₃ )-、-CON(CH ₃ ) -, or-N (CH) ₃ ) CO-; ar represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene and biphenylene, which may or may not have an organic group and/or a halogen atom as a substituent; r ⁹ And R ¹⁰ Each independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group, a benzyl group or a phenethyl group, and in the case of an alkyl group or an alkoxy group, R represents ⁹ And R ¹⁰ Form a ring or not form a ring;

q represents any one of the following structures,

in the formula, R ¹¹ represents-CH ₂ -, -NR-, -O-, or-S-, wherein R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and x represents a bond,

R ¹² represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkyl group having 1 to 10 carbon atomsAn alkoxy group.

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

6. A method of fabricating a horizontal electric field liquid crystal cell, comprising:

a step of preparing a first substrate having a liquid crystal alignment film and a second substrate having the radical generating film according to claim 5;

7. The method of manufacturing a horizontal electric field liquid crystal cell according to claim 6,

the first substrate is a substrate covered with a liquid crystal alignment film having uniaxial alignment properties.

8. The method of manufacturing a horizontal electric field liquid crystal cell according to claim 7,

the liquid crystal alignment film having uniaxial alignment is a liquid crystal alignment film for horizontal alignment.

9. The method for manufacturing a horizontal electric field liquid crystal cell according to any one of claims 6 to 8,

the comb electrode substrate is an IPS substrate or an FFS substrate.