WO2020196698A1

WO2020196698A1 - Polymer composition, liquid crystal alignment film, liquid crystal display element, and method for producing substrate having liquid crystal alignment film

Info

Publication number: WO2020196698A1
Application number: PCT/JP2020/013519
Authority: WO
Inventors: 永井　健太郎; 正人森内; 司藤枝; 亮一芦澤
Original assignee: 日産化学株式会社
Priority date: 2019-03-27
Filing date: 2020-03-26
Publication date: 2020-10-01
Also published as: CN113841085A; KR20210143802A; TW202104306A; JPWO2020196698A1

Abstract

The present invention provides: a liquid crystal alignment film to which alignment control ability is imparted with high efficiency and which has excellent tilt angle characteristics; a polymer composition that provides the liquid crystal alignment film; and a liquid crystal display element. The present invention provides a method for producing a substrate having a liquid crystal alignment film to which alignment control ability is imparted, the method comprising: [I] a step for forming a coating film by applying a polymer composition containing an organic solvent (B) and a polymer (A) having, in separate side chains, a moiety that induces in-plane alignment in a direction (S-wave direction) perpendicular to a parallel direction (P-wave direction) of polarized ultraviolet light and a moiety that induces out-of-plane alignment, to a substrate having an electrode for liquid crystal driving; [II] a step for irradiating the coating film obtained in [I] with polarized ultraviolet light having S waves as a main component from a diagonal direction; and [III] a step for heating the coating film obtained in [II].

Description

A method for producing a polymer composition, a liquid crystal alignment film, a liquid crystal display element, and a substrate having a liquid crystal alignment film.

The present invention has a novel polymer composition or a novel liquid crystal alignment agent, a liquid crystal alignment film formed by using the novel polymer composition, a substrate having the liquid crystal alignment film, a liquid crystal display element having the substrate, and the alignment film. Regarding the method of manufacturing a substrate. Furthermore, the present invention relates to a novel method for manufacturing a liquid crystal display element having excellent tilt angle characteristics.

Liquid crystal display elements are known as lightweight, thin, and low power consumption display devices, and in recent years, they have made remarkable progress, such as being used for large-scale television applications. The liquid crystal display element is configured by sandwiching the liquid crystal layer between, for example, a pair of transparent substrates provided with electrodes. In the liquid crystal display element, an organic film made of an organic material is used as the liquid crystal alignment film so that the liquid crystal is in a desired orientation state between the substrates.

That is, the liquid crystal alignment film is a constituent member of the liquid crystal display element, is formed on the surface of the substrate that sandwiches the liquid crystal in contact with the liquid crystal, and plays a role of orienting the liquid crystal in a certain direction between the substrates. The liquid crystal alignment film may be required to have a role of controlling the pretilt angle of the liquid crystal in addition to the role of orienting the liquid crystal in a certain direction such as a direction parallel to the substrate. The ability to control the orientation of the liquid crystal in such a liquid crystal alignment film (hereinafter referred to as the orientation control ability) is given by performing an orientation treatment on the organic film constituting the liquid crystal alignment film.

The rubbing method has been conventionally known as an orientation treatment method for a liquid crystal alignment film for imparting orientation control ability. The rubbing method is to rub the surface of an organic film such as polyvinyl alcohol, polyamide, or polyimide on a substrate with a cloth such as cotton, nylon, or polyester in a certain direction (rubbing) in a rubbing direction (rubbing direction). This is a method of orienting a liquid crystal. Since this rubbing method can easily realize a relatively stable orientation state of a liquid crystal, it has been used in a conventional manufacturing process of a liquid crystal display element. As the organic film used for the liquid crystal alignment film, a polyimide-based organic film having excellent reliability such as heat resistance and electrical characteristics has been mainly selected.

However, the rubbing method of rubbing the surface of a liquid crystal alignment film made of polyimide or the like may cause problems such as dust generation and generation of static electricity. In addition, due to the recent high definition of liquid crystal surface elements and the unevenness of the corresponding electrodes on the substrate and switching active elements for driving the liquid crystal, the surface of the liquid crystal alignment film cannot be rubbed uniformly with a cloth, and is uniform. Sometimes the orientation of the liquid crystal could not be achieved.

Therefore, the photo-alignment method is being actively studied as another alignment treatment method for the liquid crystal alignment film without rubbing.

There are various photo-alignment methods, but anisotropy is formed in the organic film that constitutes the liquid crystal alignment film by linearly polarized light or collimated light, and the liquid crystal is oriented according to the anisotropy.

A split-complex photo-alignment method is known as the main photo-orientation method. For example, the polyimide film is irradiated with polarized ultraviolet rays to cause anisotropic decomposition by utilizing the polarization direction dependence of the ultraviolet absorption of the molecular structure. Then, the liquid crystal is oriented by the polyimide left without decomposition (see, for example, Patent Document 1).

On the other hand, the liquid crystal alignment film also plays a role of imparting a certain inclination angle (pre-tilt angle) to the liquid crystal, and imparting the pre-tilt angle has become an important issue in the development of the liquid crystal alignment film (patented). References 2 to 5).

In addition, a photo-alignment method using a photocrosslinking type is also known. For example, polyvinyl synnamate is used to irradiate polarized ultraviolet rays to cause a dimerization reaction (crosslinking reaction) at the double bond portion of two side chains parallel to polarized light. Further, a pre-tilt angle is developed by irradiating polarized ultraviolet rays in an oblique direction (see, for example, Non-Patent Document 1). Further, in order to impart a pre-tilt angle by a photo-alignment method, it is known that a specific polymer is used to irradiate light from an oblique direction (Patent Document 6 and Non-Patent Document 2).

As in the above example, the method of aligning the liquid crystal alignment film by the photoalignment method does not require rubbing, and there is no concern about dust generation or static electricity generation. Then, the alignment treatment can be performed even on the substrate of the liquid crystal display element having an uneven surface, which is a method of orientation treatment of the liquid crystal alignment film suitable for an industrial production process. In addition, since the optical orientation method can control the orientation direction of the liquid crystal by ultraviolet rays, it is possible to form multiple regions with different orientation directions (orientation division) in the pixels and compensate for the viewing angle dependence. It is useful for improving the display quality of the display element.

Japanese Patent No. 38936559 Japanese Patent Application Laid-Open No. 02-223916 Japanese Patent Application Laid-Open No. 04-281427 Japanese Patent Application Laid-Open No. 05-043687 Japanese Patent Application Laid-Open No. 10-333153 Japanese Patent Application Laid-Open No. 2000-212310

As described above, the photo-alignment method does not require the rubbing process itself as compared with the rubbing method that has been industrially used conventionally as an orientation processing method for liquid crystal display elements, and therefore has a great advantage. Then, as compared with the rubbing method in which the orientation control ability is substantially constant by rubbing, in the photoalignment method, the orientation control ability can be controlled by changing the irradiation amount of polarized light. However, in the photo-alignment method, when trying to achieve the same orientation control ability as in the rubbing method, a large amount of polarized light irradiation may be required or stable liquid crystal orientation may not be realized. ..

For example, in the decomposition type photoalignment method described in Patent Document 1 described above, it is necessary to irradiate the polyimide film with ultraviolet light from a high-pressure mercury lamp having an output of 500 W for 60 minutes, which requires a long period of time and a large amount of ultraviolet irradiation. Become. Further, even in the case of the dimerization type or photoisomerization type photoalignment method, it may be necessary to irradiate a large amount of ultraviolet rays of about several J (joules) to several tens of J. Further, in the case of the photocrosslinking type or photoisomerization type photoalignment method, the thermal stability and photostability of the liquid crystal orientation are inferior, so that there is a problem that misalignment and display burn-in occur when the liquid crystal display element is used. was there. For example, if the product is used for a long time in an environment where it is exposed to a backlight, the tilt angle is lost due to the reverse reaction of the reaction during the orientation process by light, that is, so-called tilt return causes poor orientation. There was a problem.

Further, in the method of Patent Document 6, a halogen-based solvent such as a chloroform solvent is used because the solubility of a specific polymer is low, and there is still a problem in using it in a practical situation.

Therefore, in the photo-alignment method, high efficiency of alignment processing and realization of stable liquid crystal alignment are required, and a liquid crystal alignment film or liquid crystal capable of imparting high orientation control ability to the liquid crystal alignment film with high efficiency. Aligners are required.

An object of the present invention is to provide a substrate having a liquid crystal alignment film for a liquid crystal display element and a liquid crystal display element having the substrate, which are provided with high efficiency and orientation control ability and excellent in tilt angle characteristics.
In addition to the above object, an object of the present invention is to provide a liquid crystal display element having improved tilt angle characteristics and a liquid crystal alignment film for the element.

As a result of diligent studies to achieve the above problems, the present inventors have found the following inventions.
<1> [I] (A) A portion that induces in-plane orientation in a direction (S-wave direction) perpendicular to the parallel direction (P-wave direction) of polarized ultraviolet rays and a portion that induces out-of-plane orientation are separated. A step of applying a polymer having a side chain of (B) and a polymer composition containing (B) an organic solvent onto a substrate having an electrode for driving a liquid crystal to form a coating film;
[II] The step of irradiating the coating film obtained in [I] with ultraviolet rays polarized so that the S wave is the main component from an oblique direction; and [III] The coating film obtained in [II] is heated. Process;
A method for producing a substrate having a liquid crystal alignment film, which comprises obtaining a liquid crystal alignment film to which an orientation control ability is imparted.
<2> In the above <1>, the site that induces the in-plane orientation is preferably the site that causes photoisomerization.
<3> In <1> or <2> above, the site that induces in-plane orientation is anisotropic in the irradiation direction of polarized ultraviolet rays containing S waves as the main component, that is, in the direction parallel to the vibration direction of the S waves. It should be a group that expresses sex.
<4> In any of the above <1> to <3>, the side chain having a site that induces in-plane orientation has a structure represented by a formula selected from the following formulas (1) to (3). It is preferably a chain.

In the formula, A, B and D independently represent single bonds, -O-, -CH _2- , -COO-, -OCO-, -CONH- or -NH-CO-;
S is an alkylene group having 1 to 12 carbon atoms, and the hydrogen atom of the alkylene group may be independently replaced with a halogen atom;
T is a single bond or an alkylene group having 1 to 12 carbon atoms, and the hydrogen atom of the alkylene group may be replaced with a halogen atom;
When T is a single bond, B also represents a single bond;
Y ₁ is a divalent benzene ring;
P ₁ , Q ₁ and Q ₂ are groups independently selected from the group consisting of a benzene ring and an alicyclic hydrocarbon ring having 5 to 8 carbon atoms, respectively;
R ₁ is a hydrogen atom, -CN, a halogen atom, an alkyl group having 1 to 5 carbon atoms, a carbonyl group (alkyl having 1 to 5 carbon atoms), a cycloalkyl group having 3 to 7 carbon atoms, or an alkyl group having 1 to 5 carbon atoms. It is an alkyloxy group.
In Y ₁ , P ₁ , Q ₁ and Q ₂ , the hydrogen atom bonded to the benzene ring is independently -CN, a halogen atom, an alkyl group having 1 to 5 carbon atoms, and a (alkyl having 1 to 5 carbon atoms) carbonyl group. , Or may be substituted with an alkyloxy group having 1 to 5 carbon atoms;
X ₁ and X ₂ independently represent -O-, -COO- or -OCO-;
n1 and n2 are 0, 1 or 2, respectively.
When the number of X ₁ is 2, X ₁ together may be the same or different, when the number of X ₂ is 2, X ₂ together may be the same or different;
When the number of Q ₁ is a 2, Q ₁ each other may be the same or different, when the number Q ₂ 'is 2, Q ₂ together may be the same or different;
The broken line represents the bond with the polymerizable group.

<5> A substrate having a liquid crystal alignment film produced by the production methods described in <1> to <4> above.
<6> A liquid crystal display element having the substrate of <5> above.

<7> Step of preparing the substrate (first substrate) of <5>above;
[I'] A step of applying the polymer composition according to any one of <1> to <5> above on a second substrate to form a coating film;
[II'] The step of irradiating the coating film obtained in [I'] with ultraviolet rays polarized so that the S wave is the main component; and heating the coating film obtained in [III'] [II']. Process to do;
A step of obtaining a second substrate having the liquid crystal alignment film, which obtains a liquid crystal alignment film to which the orientation control ability is imparted by having the liquid crystal alignment film; and [IV] the liquid crystal alignment film of the first and second substrates via the liquid crystal. A step of obtaining a liquid crystal display element by arranging the first and second substrates facing each other so that the exposure directions are orthogonal to each other so as to face each other;
A method for manufacturing a liquid crystal display element, wherein the liquid crystal display element is obtained.
<8> The liquid crystal display element manufactured by the above <7>.
<9> (A) A portion that induces in-plane orientation in a direction (S-wave direction) perpendicular to the parallel direction (P-wave direction) of polarized ultraviolet rays and a portion that induces out-of-plane orientation are separate side chains. A polymer composition containing the polymer contained in (B) and an organic solvent (B).
<10> A liquid crystal alignment film obtained from the polymer composition according to <9> above.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a substrate having a liquid crystal alignment film having an orientation control ability with high efficiency and excellent tilt angle characteristics, and a liquid crystal display element having the substrate.
Since the liquid crystal display element manufactured by the method of the present invention is endowed with the orientation control ability with high efficiency, the display characteristics are not impaired even if it is continuously driven for a long time.

The polymer composition used in the production method of the present invention has (A) a site that induces in-plane orientation in the direction perpendicular to the parallel direction (P-wave direction) of polarized ultraviolet rays (P-wave direction) and out-of-plane orientation. It has a polymer (hereinafter, also simply referred to as a side chain type polymer) having a site to induce in a different side chain. Here, the site that induces in-plane orientation is a site where the tilt angle formed by light-shielding exposure to polarized UV becomes <1 ° and homogenius orientation is exhibited. The site that induces in-plane orientation originally has a structure similar to that of liquid crystal, but has the property that the structure changes due to light irradiation and the structure is no longer similar to that of liquid crystal. Due to this property, when polarized light is applied to a portion having in-plane orientation, only the portion that induces in-plane orientation in a certain direction changes its structure and loses liquid crystal orientation, while inducing in-plane orientation in a different direction. Since the structure of the portion does not change and has a structure similar to that of the liquid crystal, the liquid crystals are lined up along the structure. As a result, the liquid crystal can be oriented in the plane.

And, the site that induces out-of-plane orientation is a site that can express homeotropic orientation by itself.

The coating film obtained by using the polymer composition is a film having a side chain type polymer. This coating film is not subjected to a rubbing treatment, but is oriented by irradiation with polarized light from an oblique direction. Then, after the polarization irradiation, the side chain type polymer film is heated to obtain a coating film having an orientation control ability (hereinafter, also referred to as a liquid crystal alignment film). At this time, the slight anisotropy developed by the polarization irradiation becomes the driving force, and the liquid crystal side chain polymer itself is efficiently reoriented by self-assembly. As a result, highly efficient alignment processing can be realized as a liquid crystal alignment film, and a liquid crystal alignment film with high orientation control ability can be obtained. The present invention is characterized in that S waves are used as polarized light. By irradiating the S wave from an oblique direction, the direction in which the tilt angle appears can be defined.

Further, in the present invention, it is the portion that induces in-plane orientation that acquires orientation by light irradiation, and the tilt angle characteristic is imparted by orienting the portion that induces out-of-plane orientation. Therefore, since the tilt angle is given by the part that induces the out-of-plane orientation, even if the part that induces the in-plane orientation causes a reverse reaction due to, for example, a backlight, the part having the out-of-plane orientation is stable. Since it is maintained, so-called tilt return does not occur, and stable tilt angle characteristics can be exhibited.

Hereinafter, embodiments of the present invention will be described in detail.
<Manufacturing method of substrate having liquid crystal alignment film> and <Manufacturing method of liquid crystal display element>
The method for manufacturing a substrate having a liquid crystal alignment film of the present invention is
[I] (A) A portion that induces in-plane orientation in a direction (S-wave direction) perpendicular to the parallel direction (P-wave direction) of polarized ultraviolet rays and a portion that induces out-of-plane orientation are separate side chains. (B) A step of applying a polymer composition containing an organic solvent to a substrate having an electrode for driving a liquid crystal to form a coating film;
[II] The step of irradiating the coating film obtained in [I] with ultraviolet rays polarized so that the S wave is the main component from an oblique direction; and [III] The coating film obtained in [II] is heated. Process;
Have.
By the above steps, a liquid crystal alignment film having an orientation control ability can be obtained, and a substrate having the liquid crystal alignment film can be obtained.

The manufacturing method of the liquid crystal display element is
[IV] A step of obtaining a liquid crystal display element by arranging the first and second substrates obtained above so as to face each other so that the liquid crystal alignment films of the first and second substrates face each other via the liquid crystal.
Have. As a result, a liquid crystal display element can be obtained.

Hereinafter, each of the steps [I] to [III] and [IV] included in the production method of the present invention will be described.
<Step [I]>
In step [I], on a substrate having an electrode for driving a liquid crystal, (A) a portion that induces in-plane orientation in a direction (S wave direction) perpendicular to the parallel direction (P wave direction) of polarized ultraviolet rays, and a surface. A coating film is formed by applying a polymer composition containing a polymer having different side chains to the site that induces outer orientation and an organic solvent.

<Board>
The substrate is not particularly limited, but when the liquid crystal display element to be manufactured is a transmissive type, it is preferable to use a highly transparent substrate. In that case, the present invention is not particularly limited, and a glass substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate, or the like can be used.

As the electrode for driving the liquid crystal, ITO (Indium Tin Oxide: indium tin oxide), IZO (Indium Zinc Oxide: indium zinc oxide) and the like are preferable. Further, in the reflective liquid crystal display element, an opaque object such as a silicon wafer can be used if only one substrate is used, and in this case, a material that reflects light such as aluminum can also be used as the electrode.
As a method of forming an electrode on a substrate, a conventionally known method can be used.

<Polymer composition>
The polymer composition used in the production method of the present invention has (A) a site that induces in-plane orientation in the direction perpendicular to the parallel direction (P-wave direction) of polarized ultraviolet rays (P-wave direction) and out-of-plane orientation. It contains a polymer having an inducing site on a separate side chain and (B) an organic solvent.

<< (A) Side chain polymer >>
The component (A) separates a portion that induces in-plane orientation in a direction (S wave direction) perpendicular to the parallel direction (P wave direction) of (A) polarized ultraviolet rays and a portion that induces out-of-plane orientation. It is a polymer having in the side chain of.
The side chain type polymer (A) preferably reacts with light in the wavelength range of 250 to 400 nm and exhibits liquid crystallinity in the temperature range of 100 to 300 ° C.
The side chain polymer (A) preferably has a photosensitive side chain that reacts with light in the wavelength range of 250 to 400 nm.
The side chain polymer (A) preferably has a mesogen group because it exhibits liquid crystallinity in a temperature range of 100 to 300 ° C.

In the side chain polymer (A), the portion that induces in-plane orientation in the direction perpendicular to the parallel direction (P wave direction) of polarized ultraviolet rays (P wave direction) is bonded to the main chain, and is sensitive to light. Can cause an isomerization reaction. In this case, even if it is exposed to external stress such as heat, the realized orientation control ability can be stably maintained for a long period of time. The structure of the site that induces in-plane orientation is not particularly limited as long as it satisfies such characteristics, but it is preferable that the side chain structure has a rigid mesogen component. In this case, stable liquid crystal orientation can be obtained when the side chain polymer is used as a liquid crystal alignment film.

The side chain polymer (A) has a portion that induces out-of-plane orientation in the direction perpendicular to the parallel direction (P wave direction) of polarized ultraviolet rays (P wave direction), thereby achieving a desired tilt angle. A liquid crystal alignment film to be expressed is given. It is considered that this is because when used as a liquid crystal alignment film, anisotropy is exhibited by the side chain type polymer being close to the site where the out-of-plane orientation is induced, and a tilt angle can be obtained.

The structure of the polymer has, for example, a main chain and a side chain bonded thereto, and the side chain contains a mesogen component such as a biphenyl group, a terphenyl group, a phenylcyclohexyl group, a phenylbenzoate group, or an azobenzene group, and light The structure can have a photosensitive group that undergoes an isomerization reaction in response to the above.

More specific examples of the structure of the photosensitive side chain polymer film capable of exhibiting liquidity include hydrocarbons, (meth) acrylates, itaconates, fumarates, maleates, α-methylene-γ-butyrolactone, styrene, and the like. A main chain composed of at least one selected from the group consisting of radically polymerizable groups such as vinyl, maleimide, and norbornene and siloxane, a side chain having a site that induces in-plane orientation, and an out-of-plane orientation are induced. It is preferable that the structure has a side chain having a site and, if desired, a side chain having liquidity.

The side chain having a site that induces in-plane orientation in the side chain type polymer of the component (A) is preferably a side chain having a structure consisting of at least one of the following formulas (1) to (3). ..

From the viewpoint of solubility in a solvent, the photo-oriented side chain preferably has a total of 3 or less benzene rings and naphthalene rings in one side chain.
Further, in the process described in the present application, in the process described in the present application, in the irradiation direction of the polarized ultraviolet rays, that is, the vibration direction of the S waves, the anisotropy is easily imparted by the irradiation of the polarized ultraviolet rays containing the S wave as the main component from the oblique direction. On the other hand, it is preferable that the group exhibits anisotropy in the parallel direction.

The site that induces out-of-plane orientation is not particularly limited, but a group containing a hydrocarbon group having 1 to 17 carbon atoms is preferable, and specifically, a group represented by the formula (4) is preferable. Is.

In formula (4), Y ¹ represents a single bond or -O-, -CH ₂ O-, -COO-, -OCO-, -NH _2- , -NHCO-, -NH-CO-O- And represents a binding group selected from -NH-CO-NH-
Y ² represents a single bond, an alkylene group having 1 to 15 carbon atoms or a -CH _2- CH (OH) -CH _2- group, or a divalent cyclic group selected from a benzene ring, a cyclohexane ring or a heterocycle. Represented, any hydrogen atom on the cyclic group may be substituted with Z.
Y ³ represents a single bond or an alkylene group having 1 to 15 carbon atoms,
Y ⁴ represents a single bond, a benzene ring, a divalent organic group having a divalent cyclic group or a steroid skeleton having a carbon number of 17-30, selected from the cyclohexane ring or heterocyclic ring, any hydrogen on the cyclic group The atom may be replaced with Z,
Y ⁵ represents a divalent cyclic group selected from a benzene ring, a cyclohexane ring or a heterocycle, and any hydrogen atom on these cyclic groups may be substituted with Z, and m is an integer of 0 to 4. When m is 2 or more, Y ⁵ may be the same or different from each other.
Y ⁶ represents a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkyl fluoride group having 1 to 17 carbon atoms, an alkoxyalkyl group having 2 to 17 carbon atoms, or an alkoxyalkyl group having 2 to 17 carbon atoms. ,
Z represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an alkyl fluoride group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms or a fluorine atom, and an alkyl group. , Alkoxy group, alkyl fluoride group and alkoxy fluoride group may have 1 to 3 of the above-mentioned bonding groups in the group as long as the bonding groups are not adjacent to each other.
In Y ² ~ ^{Y 6,} alkylene _{group, -CH 2 -CH (OH) -CH} 2 - group, a divalent cyclic group, a divalent organic group having a steroid skeleton, an alkyl group, an alkoxyalkyl group, fluorinated alkyl The group and the fluorinated alkoxyalkyl group may be bonded to a group adjacent to them via the above-mentioned bonding group.
However, the total number of carbon atoms of the substituents Y 2 ^~ Y ⁶ represents is 1-30, including the number of carbon atoms of the linking group.

Examples of the alkylene group having 1 to 15 carbon atoms include a divalent group obtained by removing one hydrogen atom from the alkyl group having 1 to 15 carbon atoms among the alkyl groups having 1 to 17 carbon atoms, which will be described later. Examples thereof include methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene group and the like.

Specific examples of the heterocycle include a pyrazole ring, an imidazole ring, an oxazole ring, a thiazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a quinoline ring, an isoquinoline ring, a carbazole ring, a purine ring, a thiazizole ring, a pyridazine ring, and a pyrazoline ring. Examples thereof include a triazine ring, a pyrazolidine ring, a triazole ring, a pyrazine ring, a benzimidazole ring, a synnoline ring, a phenanthroline ring, an indole ring, a quinoxaline ring, a benzthiazole ring, a phenothiazine ring, an oxadiazole ring, and an acrydin ring. , Pyrazole ring, imidazole ring, pyrazole ring, pyridine ring, pyrimidine ring, carbazole ring, pyridazine ring, pyrazoline ring, triazole ring, pyrazolidine ring, triazole ring, pyrazine ring, benzimidazole ring are preferable.

Specific examples of the divalent organic group having a steroid skeleton having 17 to 30 carbon atoms include cholesteryl, androsteryl, β-cholesteryl, epiandrosteryl, ergosteryl, estryl, 11α-hydroxymethylsteryl, 11α-progesteryl, and lanosteryl. , Melatranil, Methyltestrosteryl, Noretisteryl, Pregnenonyl, β-Cytosteryl, Stigmasteryl, Testosteryl, and Divalent organic groups having a structure in which two hydrogen atoms are removed from a structure selected from cholesterol acetate and the like. , Not limited to these.

As alkyl groups having 1 to 17 carbon atoms, methyl, ethyl, propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, 1 -Methyl-n-hexyl, 2-methyl-n-hexyl, 3-methyl-n-hexyl, 1,1-dimethyl-n-pentyl, 1,2-dimethyl-n-pentyl, 1,3-dimethyl-n -Pentyl, 2,2-dimethyl-n-pentyl, 2,3-dimethyl-n-pentyl, 3,3-dimethyl-n-pentyl, 1-ethyl-n-pentyl, 2-ethyl-n-pentyl, 3 -Ethyl-n-pentyl, 1-methyl-1-ethyl-n-butyl, 1-methyl-2-ethyl-n-butyl, 1-ethyl-2-methyl-n-butyl, 2-methyl-2-ethyl -N-Butyl, 2-Ethyl-3-methyl-n-Butyl, n-octyl, 1-methyl-n-Heptyl, 2-Methyl-n-Heptyl, 3-Methyl-n-Heptyl, 1,1-dimethyl -N-hexyl, 1,2-dimethyl-n-hexyl, 1,3-dimethyl-n-hexyl, 2,2-dimethyl-n-hexyl, 2,3-dimethyl-n-hexyl, 3,3-dimethyl -N-hexyl, 1-ethyl-n-hexyl, 2-ethyl-n-hexyl, 3-ethyl-n-hexyl, 1-methyl-1-ethyl-n-pentyl, 1-methyl-2-ethyl-n -Pentyl, 1-methyl-3-ethyl-n-pentyl, 2-methyl-2-ethyl-n-pentyl, 2-methyl-3-ethyl-n-pentyl, 3-methyl-3-ethyl-n-pentyl , N-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl and the like.

Examples of the alkyl fluoride group having 1 to 17 carbon atoms include a group in which at least one hydrogen atom in the alkyl group having 1 to 17 carbon atoms is replaced with a fluorine atom, and specific examples thereof include fluoromethyl and difluoromethyl. , Trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, heptafluoropropyl, 2,2,3,3,3-pentafluoropropyl, 2,2,3,3-tetrafluoropropyl, 2 , 2,2-Trifluoro-1- (trifluoromethyl) ethyl, nonafluorobutyl, 4,4,4-trifluorobutyl, undecafluoropentyl, 2,2,3,3,4,5, 5,5-Nonafluoropentyl, 2,2,3,3,4,5,5-octafluoropentyl, tridecafluorohexyl, 2,2,3,3,4,5,5,6 , 6,6-Undecafluorohexyl, 2,2,3,3,4,5,5,6,6-decafluorohexyl, 3,3,4,4,5,5,6,6 , 6-Nonafluorohexyl and the like.

Specific examples of the fluorinated alkoxy group having 1 to 17 carbon atoms include a group in which an oxygen atom (—O—) is bonded to the above-mentioned alkyl fluoride group having 1 to 17 carbon atoms, and specific examples thereof include fluoro. Methoxy, difluoromethoxy, trifluoromethoxy, pentafluoroethoxy, 2,2,2-trifluoroethoxy, heptafluoropropoxy, 2,2,3,3,3-pentafluoropropoxy, 2,2,3,3-tetra Fluoropropoxy, 2,2,2-trifluoro-1- (trifluoromethyl) ethoxy, nonafluorobutoxy, 4,4,4-trifluorobutoxy, undecafluoropentyloxy, 2,2,3,3,4 , 4,5,5,5-nonafluoropentyloxy, 2,2,3,3,4,5,5-octafluoropentyloxy, tridecafluorohexyloxy, 2,2,3,3,4 , 4,5,5,6,6-6-Undecafluorohexyloxy, 2,2,3,3,4,5,5,6,6-decafluorohexyloxy, 3,3,4 , 4,5,5,6,6,6-nonafluorohexyloxy group and the like.

Examples of the alkyl group having 1 to 3 carbon atoms in Z include those having 1 to 3 carbon atoms among the groups exemplified in 1 to 17 carbon atoms, and the alkoxy group having 1 to 3 carbon atoms includes Among the groups exemplified by the above-mentioned alkoxy groups having 1 to 17 carbon atoms, those having 1 to 3 carbon atoms can be mentioned, and examples of the alkyl fluoride group having 1 to 3 carbon atoms include the above-mentioned alkyl fluoride having 1 to 17 carbon atoms. Among the groups exemplified by the groups, those having 1 to 3 carbon atoms can be mentioned, and as the fluorinated alkoxy group having 1 to 3 carbon atoms, among the groups exemplified by the fluorinated alkoxy groups having 1 to 17 carbon atoms, carbon The number 1 to 3 can be mentioned.

Among these, from the viewpoint of ease of synthesis and the like, Y ¹ is preferably a single bond, Y ² is preferably a benzene ring or a cyclohexane ring, and Y ³ is preferably an alkylene group having 1 to 15 carbon atoms and having 1 to 15 carbon atoms. 1 to 9 alkylene groups are more preferable, Y ⁴ is preferably a benzene ring, a cyclohexane ring or a divalent organic group having a steroid skeleton having 17 to 30 carbon atoms, and Y ⁵ is a benzene ring or a cyclohexane ring. preferably, Y ⁶ represents an alkyl group having 1 to 17 carbon atoms, fluorinated alkyl group having 1 to 10 carbon atoms, fluorinated alkoxyalkyl group an alkoxyalkyl group or a C 2-17 having 2 to 17 carbon atoms preferably, carbon Alkyl groups having a number of 1 to 12 are more preferable, and alkyl groups having 1 to 9 carbon atoms are even more preferable.

However, when Y ⁴ is a divalent organic group having a steroid skeleton, Y ⁶ is preferably a hydrogen atom.

Further, from the viewpoint of availability of raw materials, ease of synthesis, etc., m is preferably 0 to 3, more preferably 0 to 2, and even more preferably 0 or 1.

The alkylene group, alkyl group, alkyl fluoride group, alkoxy group and alkoxy fluoride group may have 1 to 3 of the above-mentioned bonding groups as long as the bonding groups are not adjacent to each other. in ^Y 2 ~ ^{Y 6,} alkylene _{group, -CH 2 -CH (OH) -CH} 2 - group, a divalent cyclic group, a divalent organic group, an alkyl group and fluorinated alkyl group having a steroid skeleton, It may be bonded to the groups adjacent to them via the above-mentioned bonding group.

The total carbon number of the substituents represented by Y ² to Y ⁶ is 1 to 30, but 1 to 20 is preferable. When the terminal has an alkyl group, the terminal alkyl group is preferably an alkyl group having 1 to 17 carbon atoms.

In addition to sites for inducing the out-of-plane orientation (a-1), for example, the ^Y 1 ~ ^{Y 4} is a single bond, m is 2 or 3, ^{Y 5} is a benzene ring or A site (a-2) which is a cyclohexane ring and Y ⁶ is an alkyl group having 1 to 17 carbon atoms and which induces out-of-plane orientation can also be preferably used.

Specific examples of the site (a-2) that induces such out-of-plane orientation include the groups shown in the following (a-2-1) to (a-2-7), but are limited to these. It's not something.
In the formula, Y ⁶ is the same as above, and Y represents a single bond, or -O-, -CH ₂ O-, -COO-, -OCO-, -NH _2- , -NHCO-, -NH-CO. Represents a binding group selected from -O- and -NH-CO-NH-.

Furthermore, in addition to the site of inducing the out-of-plane orientation (a-1) and (a-2), for example, the ^Y 1 ~ ^{Y 3} is a single bond, ^{Y 4} is a steroid skeleton having 17-30 carbon atoms A site (a-3) that induces out-of-plane orientation, which is a divalent organic group having, m is 0, and Y ⁶ is a hydrogen atom, can also be preferably used.

Examples of the site (a-3) that induces such out-of-plane orientation include, but are limited to, the groups shown in the following (a-3-1) to (a-3-8). It's not a thing. In the formula, * represents the bonding position.

The site for inducing the out-of-plane orientation described above is a polymer having an unsaturated double bond such as a (meth) acrylic monomer, a vinyl monomer, a styrene monomer, or a maleimide monomer. Although it can be introduced, in this case as well, it is preferable to introduce it into the polymer using a (meth) acrylic monomer having a site that induces the out-of-plane orientation.

Further, the side chain type polymer (A) preferably has one or more liquid crystal side chains selected from the group consisting of the following formulas (21) to (31).
In the formula, A and B have the same definition as above;
q1 and q2 are independently 0 or 1, respectively.
Y ₃ is a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a nitrogen-containing heterocycle, and alicyclic hydrocarbons having 5 to 8 carbon atoms, and, with a group selected from the group consisting of Yes, the hydrogen atoms attached to them may be independently substituted with -NO ₂ , -CN, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms;
R ₃ contains hydrogen atom, -NO ₂ , -CN, -CH = C (CN) ₂ , -CH = CH-CN, halogen atom, monovalent benzene ring, naphthalene ring, biphenyl ring, furan ring, and nitrogen. Represents a heterocycle, an alicyclic hydrocarbon having 5 to 8 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms;
l represents an integer of 1 to 12, m represents an integer of 0 to 2, but in equations (23) to (24), the sum of all m is 2 or more, and equations (25) to (26). ), The sum of all m is 1 or more, and m1, m2, and m3 independently represent integers of 1 to 3;
R ₂ is a hydrogen atom, -NO ₂ , -CN, a halogen atom, a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a nitrogen-containing heterocycle, and an alicyclic hydrocarbon having 5 to 8 carbon atoms. And represents an alkyl group or an alkyloxy group;
Z ₁ and Z ₂ represent a single bond, -CO-, -CH ₂ O-, -CH = N-, -CF _2- .

[Monomer having a site that induces in-plane orientation]
A monomer having an organic site for in-plane orientation is a monomer capable of forming a polymer having a site for inducing in-plane orientation in the side chain site of the polymer when the polymer is formed. ..
Examples of the monomer having an organic site for in-plane orientation include the monomer (A-1) having the structure of the formula (1), the monomer (A-2) having the structure of the formula (2), and the structure of the formula (3). The monomer (A-3) having is preferable.

The monomer (A-1) and the monomer (A-2) are radically polymerizable groups such as hydrocarbons, (meth) acrylates, itacones, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, and norbornene. And a monomer having a polymerizable group composed of at least one selected from the group consisting of a trialkoxysilyl group and a photosensitive side chain selected from the structures represented by the above formulas (1) and (2) is preferable. ..

The polymerizable group is preferably selected from the groups represented by the following formulas PG1 to PG8. Of these, an acrylic group or a methacrylic group represented by PG1 is preferable from the viewpoint of easy control of the polymerization reaction and stability of the polymer. In the formula, the broken line represents the bond with the photosensitive side chain represented by the above formulas (1), (2) or (3). Further, in the formula PG1, M1 is a hydrogen atom or a methyl group.

Examples of the monomer (A-1) include monomers selected from the following formulas A-1-1 to A-1-12. In the following formulas A1-1 to A1-12, PG represents a polymerizable group selected from the groups represented by the above formulas PG1 to PG8, and s1 represents the number of methylene groups and is an integer of 2 to 9.

Examples of the monomer (A-2) include monomers selected from the following formulas A-2-1 to A-2-8. In the following formulas A2-1 to A2-8, PG represents a polymerizable group selected from the groups represented by the above formulas PG1 to PG8, and s1 and s2 each independently represent the number of methylene groups of 2 to 9. It is an integer.

Some of the above-mentioned monomers (A-1) and (A-2) are commercially available, and some can be produced by the method described in, for example, International Patent Application Publication WO2014 / 074785.

The monomer (A-3) is a monomer having a group (3), and although this group (3) does not have liquid crystal properties by itself, it has a structure similar to that of liquid crystals by being dimerized by hydrogen bonds in the plane. It becomes. When the structure is changed by light irradiation, the hydrogen bond is cleaved and the structure is not similar to that of the liquid crystal. As a result, it can be a site that induces in-plane orientation by the above mechanism.
Examples of the monomer (A-3) having such a group (3) include a monomer selected from the following formulas A-3-1 to A-3-5. In the following formula, PG represents a polymerizable group selected from the groups represented by the above formulas PG1 to PG8, and s1 represents the number of methylene groups, which is an integer of 2 to 9.

Examples of the monomer (A-3) having the structure represented by the above formula (3) include 4- (6-methacryloxyhexyl-1-oxy) cinnamic acid and 4- (6-acrylicoxyhexyl-1). -Oxy) cinnamic acid, 4- (3-methacryloxypropyl-1-oxy) cinnamic acid, 4- (4- (6-methacryloxyhexyl-1-oxy) benzoyloxy) cinnamic acid and the like. ..

[Monomer having a site that induces out-of-plane orientation]
Specific monomers include alkyl esters of (meth) acrylic acid, alkyl vinyl ethers, 2-alkyl styrenes, 3-alkyl styrenes, 4-alkyl styrenes, and N-alkyl maleimides, the alkyl groups having 1 to 20 carbon atoms. Things can be mentioned.
These monomers can be produced by known methods, and some are commercially available.

When a (meth) acrylic monomer having a site that induces out-of-plane orientation represented by the above formula (4) is used to introduce a site that induces out-of-plane orientation into the polymer, the out-of-plane orientation is induced. The side chain having the site to be formed is represented by the following formula (4').

As the monomer having such an out-of-plane orientation group, for example, a monomer represented by a formula selected from the group consisting of the following formulas M3-1 to M3-4 is preferable. In the following formula, X and Y independently represent a single bond, -O-, -CH _2- , -NH-, -CO-, -COO- or -OCO-, and R is a methyl group, a methoxy group or a tri. It represents a fluoromethyl group, PG represents a polymerizable group selected from the groups represented by the above formulas PG1 to PG8, s1 represents the number of methylene groups, is an integer of 2 to 9, and s2 is the number of methylene groups. Is an integer of 2 to 12.

[Liquid crystal side chain monomer]
The liquid crystal side chain monomer is a monomer in which a polymer derived from the monomer exhibits liquid crystallinity and the polymer can form a mesogen group at a side chain site.

As the mesogen group of the side chain, even if it is a group having a mesogen structure by itself such as biphenyl or phenylbenzoate, or a group having a mesogen structure by hydrogen bonding between side chains such as benzoic acid. Good. The following structure is preferable as the mesogen group contained in the side chain.

More specific examples of liquid side chain monomers include hydrocarbons, (meth) acrylates, itaconates, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, norbornene and other radically polymerizable groups. It is preferable that the structure has a polymerizable group composed of at least one selected from the group consisting of siloxane and a side chain composed of at least one of the above formulas (21) to (31).

Among such liquid crystal monomers, as the monomer having a carboxyl group, a monomer represented by a formula selected from the group consisting of the following formulas M2-1 to M2-5 can also be used. In the following formula, PG represents a polymerizable group selected from the groups represented by the above formulas PG1 to PG8, and s1 represents the number of methylene groups, which is an integer of 2 to 9.

Further, as a monomer having a substituent that expresses liquid crystallinity, which is an example of the other monomer, a monomer represented by a formula selected from the group consisting of the following formulas M2-10 to M2-16 can also be used. In the following formula, PG represents a polymerizable group selected from the groups represented by the above formulas PG1 to PG8, and s1 represents the number of methylene groups, which is an integer of 2 to 9.

[Monomer having side chain (a)]
The polymer which is the component (A) of the present application has a side chain (a) having a group selected from a nitrogen-containing aromatic heterocyclic group, an amide group and a urethane group in order to obtain a more durable liquid crystal alignment film. You may also have. In order to produce a polymer having a side chain (a), the monomer having a side chain (a) may be copolymerized.

Examples of the monomer having such a side chain (a) include hydrocarbons, (meth) acrylates, itacones, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, norbornene and other radically polymerizable groups and siloxanes. It is preferable that the structure has a polymerizable group composed of at least one selected from the above group and a side chain having a nitrogen-containing aromatic heterocyclic group, an amide group and a urethane group. The NH of the amide group and the urethane group may or may not be substituted. Examples of the substituent which may be substituted include an alkyl group, an amino group protecting group, a benzyl group and the like.

The nitrogen-containing aromatic heterocycle consists of a group consisting of the following formulas [20a], [20b] and [20c] (in the formula, Z ₂ is a linear or branched alkyl group having 1 to 5 carbon atoms). It is preferably an aromatic heterocycle containing at least one selected structure, preferably 1 to 4 structures.

Specifically, pyrol ring, imidazole ring, oxazole ring, thiazole ring, pyrazole ring, pyridine ring, pyrimidine ring, quinoline ring, pyrazoline ring, isoquinoline ring, carbazole ring, purine ring, thiaziazole ring, pyridazine ring, pyrazoline ring, Examples thereof include a triazine ring, a pyrazoline ring, a triazole ring, a pyrazine ring, a benzimidazole ring, a tynoline ring, a phenanthroline ring, an indole ring, a quinoxaline ring, a benzothiazole ring, a phenothiazine ring, an oxaziazole ring, and an aclysin ring. Further, the carbon atom of these nitrogen-containing aromatic heterocycles may have a substituent containing a heteroatom.
Of these, for example, a pyridine ring is preferable.

Among such monomers, examples of the monomer having a nitrogen-containing aromatic heterocyclic group include, for example, 2- (2-pyridylcarbonyloxy) ethyl (meth) acrylate and 2- (3-pyridylcarbonyloxy). Ethyl (meth) acrylate, 2- (4-pyridylcarbonyloxy) ethyl (meth) acrylate, and the like can be mentioned.

Specific examples of the monomer having an amide group or a urethane group include 2- (4-methylpiperidin-1-ylcarbonylamino) ethyl (meth) acrylate and 4- (6-methacryloyloxyhexyloxy) benzoic acid. Examples thereof include N- (tert-butyloxycarbonyl) piperidine-4-yl ester and 4- (6-methacryloyloxyhexyloxy) benzoic acid 2- (tert-butyloxycarbonylamino) ethyl ester.

The side chain type polymer (A) includes the above-mentioned monomer having a site for inducing in-plane orientation, a monomer having a site for inducing out-of-plane orientation, a monomer having a liquid liquid side chain if desired, and a side chain if desired. It can be obtained by a copolymerization reaction with the monomer having (a). Furthermore, it can be copolymerized with other monomers as long as the effects of the present invention are not impaired.

Examples of other monomers include industrially available radical polymerization-reactive monomers.
Specific examples of other monomers include unsaturated carboxylic acids, acrylic acid ester compounds, methacrylic acid ester compounds, maleimide compounds, acrylonitrile, maleic acid anhydrides, styrene compounds and vinyl compounds.

Specific examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid and the like.

Examples of the acrylic acid ester compound include methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthryl acrylate, anthryl methyl acrylate, phenyl acrylate, 2,2,2-trifluoroethyl acrylate, and tert-butyl. Acrylate, cyclohexyl acrylate, isobornyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, 3-methoxybutyl acrylate, 2-methyl-2-adamantyl acrylate, 2- Examples thereof include propyl-2-adamantyl acrylate, 8-methyl-8-tricyclodecyl acrylate, and 8-ethyl-8-tricyclodecyl acrylate.

Examples of the methacrylate ester compound include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, benzyl methacrylate, naphthyl methacrylate, anthryl methacrylate, anthryl methyl methacrylate, phenyl methacrylate, 2,2,2-trifluoroethyl methacrylate and tert-butyl. Methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2-ethoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 3-methoxybutyl methacrylate, 2-methyl-2-adamantyl methacrylate, 2- Examples thereof include propyl-2-adamantyl methacrylate, 8-methyl-8-tricyclodecyl methacrylate, 8-ethyl-8-tricyclodecyl methacrylate and the like.

Examples of the vinyl compound include vinyl ether, methyl vinyl ether, benzyl vinyl ether, 2-hydroxyethyl vinyl ether, phenyl vinyl ether, propyl vinyl ether and the like.

Examples of the styrene compound include styrene, 2-methylstyrene, 3-methylstyrene, 2-chlorostyrene, 3-chlorostyrene, 2-bromostyrene, 3-bromostyrene and the like.

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

The content of the site that induces out-of-plane orientation in the side chain polymer of the present invention is preferably 0.1 mol% to 50 mol%, preferably 0.5 mol% to 40, from the viewpoint of affecting the liquid crystal orientation. More preferably, 1 mol% to 35 mol%.

The content of the side chain having a site that induces in-plane orientation in the side chain type polymer of the present invention is preferably 20 mol% to 99.9 mol%, preferably 30 mol% to 95 mol, from the viewpoint of liquid crystal orientation. % Is more preferable, and 40 mol% to 90 mol% is further preferable.

The content of the liquid crystal side chain in the side chain polymer of the present invention is preferably 80 mol% or less, more preferably 10 mol% to 70 mol%, and 20 mol% when it is contained, from the viewpoint of liquid crystal orientation. -60 mol% is more preferred.

The content of the side chain (a) in the side chain type polymer of the present invention is preferably 60 mol% or less, and more preferably 0.3 mol% to 50 mol% when it is contained, from the viewpoint of expression of tilt angle. More preferably, it is 0.5 mol% to 30 mol%.

The side chain type polymer of the present invention includes a side chain having a site that induces out-of-plane orientation, a side chain having a site that induces in-plane orientation, a liquid crystal side chain, and other side chains other than the side chain (a). It may be contained. The total content of the side chain having a site that induces out-of-plane orientation, the side chain having a site that induces in-plane orientation, the liquid crystal side chain, and the side chain (a) is less than 100%. If so, the rest.

The method for producing the side chain polymer of the present embodiment is not particularly limited, and a general-purpose method that is industrially handled can be used. Specifically, it can be produced by cationic polymerization, radical polymerization, or anionic polymerization using a vinyl group of a liquid crystal side chain monomer or a photoreactive side chain monomer. Of these, radical polymerization is particularly preferable from the viewpoint of ease of reaction control.

As the polymerization initiator for radical polymerization, known compounds such as a radical polymerization initiator and a reversible addition-cracking chain transfer (RAFT) polymerization reagent can be used.

The radical thermal polymerization initiator is a compound that generates radicals when heated above the decomposition temperature. Examples of such radical thermal polymerization initiators include ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), diacyl peroxides (acetyl peroxide, benzoyl peroxide, etc.), and hydroperoxides (peroxidation). Hydrogen, tert-butylhydroxide, cumenehydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyketars (dibutylperoxy cyclohexane, etc.) Etc.), alkyl peresters (peroxyneodecanic acid-tert-butyl ester, peroxypivalic acid-tert-butyl ester, peroxy2-ethylcyclohexanoic acid-tert-amyl ester, etc.), persulfates (potassium persulfate, etc.) Examples thereof include sodium persulfate, ammonium persulfate, etc.) and azo compounds (azobisisobutyronitrile, and 2,2′-di (2-hydroxyethyl) azobisisobutyronitrile, etc.). As such a radical thermal polymerization initiator, one type may be used alone, or two or more types may be used in combination.

The radical photopolymerization initiator is not particularly limited as long as it is a compound that initiates radical polymerization by light irradiation. Examples of such radical photopolymerization initiators include benzophenone, Michler's ketone, 4,4'-bis (diethylamino) benzophenone, xanthone, thioxanthone, isopropylxanthone, 2,4-diethylthioxanthone, 2-ethylanthraquinone, acetophenone and 2-hydroxy. -2-Methylpropiophenone, 2-Hydroxy-2-methyl-4'-isopropylpropiophenone, 1-hydroxycyclohexylphenylketone, isopropylbenzoin ether, isobutylbenzoin ether, 2,2-diethoxyacetophenone, 2,2 -Dimethoxy-2-phenylacetophenone, camphorquinone, benzanthron, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-( 4-Molholinophenyl) -butanone-1, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 4,4'-di (t-butylperoxycarbonyl) benzophenone, 3,4,4'-tri ( t-Butylperoxycarbonyl) benzophenone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2- (4'-methoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (3' , 4'-dimethoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (2', 4'-dimethoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2 -(2'-methoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4'-pentyloxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 4- [PN, N-di (ethoxycarbonylmethyl)]-2,6-di (trichloromethyl) -s-triazine, 1,3-bis (trichloromethyl) -5- (2'-chlorophenyl) -s- Triazine, 1,3-bis (trichloromethyl) -5- (4'-methoxyphenyl) -s-triazine, 2- (p-dimethylaminostyryl) benzoxazole, 2- (p-dimethylaminostyryl) benzthiazole, 2-Mercaptobenzothiazole, 3,3'-carbonylbis (7-diethylaminocoumarin), 2- (o-chlorophenyl) -4,4', 5,5'-tetraphenyl-1,2'-biimidazole, 2 , 2'-bi Su (2-chlorophenyl) -4,4', 5,5'-tetrakis (4-ethoxycarbonylphenyl) -1,2'-biimidazole, 2,2'-bis (2,4-dichlorophenyl) -4, 4', 5,5'-Tetraphenyl-1,2'-biimidazole, 2,2'bis (2,4-dibromophenyl) -4,4', 5,5'-Tetraphenyl-1,2' -Bimidazole, 2,2'-bis (2,4,6-trichlorophenyl) -4,4', 5,5'-tetraphenyl-1,2'-bimidazole, 3- (2-methyl-2) -Dimethylaminopropionyl) carbazole, 3,6-bis (2-methyl-2-morpholinopropionyl) -9-n-dodecylcarbazole, 1-hydroxycyclohexylphenylketone, bis (5-2,4-cyclopentadiene-1- Il) -bis (2,6-difluoro-3- (1H-pyrrole-1-yl) -phenyl) titanium, 3,3', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 3,3 ', 4,4'-Tetra (t-hexylperoxycarbonyl) benzophenone, 3,3'-di (methoxycarbonyl) -4,4'-di (t-butylperoxycarbonyl) benzophenone, 3,4'-di ( Methylcarbonyl) -4,3'-di (t-butylperoxycarbonyl) benzophenone, 4,4'-di (methoxycarbonyl) -3,3'-di (t-butylperoxycarbonyl) benzophenone, 2- (3- (3-) Methyl-3H-benzothiazole-2-ylidene) -1-naphthalen-2-yl-etanone, or 2- (3-methyl-1,3-benzothiazole-2 (3H) -iriden) -1- (2-) Benzoyl) Etanone and the like can be mentioned. These compounds may be used alone or in admixture of two or more.

The radical polymerization method is not particularly limited, and an emulsion polymerization method, a suspension polymerization method, a dispersion polymerization method, a precipitation polymerization method, a massive polymerization method, a solution polymerization method and the like can be used.

The organic solvent used for the polymerization reaction of the photosensitive side chain polymer capable of exhibiting liquid crystallinity is not particularly limited as long as the produced polymer dissolves. Specific examples are given below.

N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide , Γ-Butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethylamyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cell solve, ethyl cell solve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl Carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl Ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene Glycol monoacetate Monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butylate, butyl ether , Diisobutylketone, 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, acetate Ethyl, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropio Acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglime, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N, N-dimethylpropanamide, 3 Examples thereof include -ethoxy-N, N-dimethylpropanamide, 3-butoxy-N, N-dimethylpropanamide and the like.

These organic solvents may be used alone or in combination. Further, even if the solvent does not dissolve the produced polymer, it may be mixed with the above-mentioned organic solvent and used as long as the produced polymer does not precipitate.
Further, in radical polymerization, oxygen in the organic solvent causes inhibition of the polymerization reaction, so it is preferable to use an organic solvent degassed to the extent possible.

The polymerization temperature at the time of radical polymerization can be selected from any temperature of 30 to 150 ° C, but is preferably in the range of 50 to 100 ° C. The reaction can be carried out at any concentration, but if the concentration is too low, it becomes difficult to obtain a polymer having a high mass, and if the concentration is too high, the viscosity of the reaction solution becomes too high, making uniform stirring difficult. Therefore, the monomer concentration is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial reaction can be carried out at a high concentration and then an organic solvent can be added.

In the above-mentioned radical polymerization reaction, when the ratio of the radical polymerization initiator is large with respect to the monomer, the molecular weight of the obtained polymer is small, and when the ratio of the radical polymerization initiator is small, the molecular weight of the obtained polymer is large. It is preferably 0.1 to 10 mol% with respect to the monomer to be polymerized. Further, various monomer components, solvents, initiators and the like can be added at the time of polymerization.

[Recovery of polymer]
When recovering the produced polymer from the reaction solution of the photosensitive side chain polymer capable of expressing liquidity obtained by the above reaction, the reaction solution is put into a poor solvent and their weights are increased. The coalescence may be precipitated. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, heptane, butyl cellsolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, water and the like. The polymer which has been put into a poor solvent and precipitated can be collected by filtration and then dried at normal temperature or by heating under normal pressure or reduced pressure. Further, if the operation of redistributing the polymer recovered by precipitation in an organic solvent and repeating the operation of recovering the precipitate again 2 to 10 times, impurities in the polymer can be reduced. Examples of the poor solvent at this time include alcohols, ketones, hydrocarbons, and the like, and it is preferable to use three or more kinds of poor solvents selected from these because the purification efficiency is further improved.

The molecular weight of the side chain polymer (A) of the present invention is measured by the GPC (Gel Permeation Chromatography) method in consideration of the strength of the obtained coating film, the workability at the time of forming the coating film, and the uniformity of the coating film. The weight average molecular weight obtained is preferably 2000 to 1000000, more preferably 5000 to 500,000.

[Preparation of polymer composition]
The polymer composition used in the present invention is preferably prepared as a coating liquid so as to be suitable for forming a liquid crystal alignment film. That is, the polymer composition used in the present invention is preferably prepared as a solution in which a resin component for forming a resin film is dissolved in an organic solvent. Here, the resin component is a resin component containing a photosensitive side-chain type polymer capable of exhibiting liquid crystallinity as described above. At that time, the content of the resin component is preferably 1 to 20% by mass, more preferably 3 to 15% by mass, and particularly preferably 3 to 10% by mass.

In the polymer composition of the present embodiment, all of the above-mentioned resin components may be photosensitive side-chain polymers capable of exhibiting the above-mentioned liquid crystallinity, but the liquid crystal expression ability and photosensitive performance are not impaired. Other polymers may be mixed in the range. At that time, the content of the other polymer in the resin component is 0.5 to 80% by mass, preferably 1 to 50% by mass.
Examples of such other polymers include polymers composed of poly (meth) acrylate, polyamic acid, polyimide, etc., and are not photosensitive side chain polymers capable of exhibiting liquid crystallinity.

<(B) Organic solvent>
The organic solvent used in the polymer composition used in the present invention is not particularly limited as long as it is an organic solvent that dissolves the resin component. Specific examples are given below.
N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methyl-ε-caprolactam, 2-pyrrolidone, N-ethyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, Dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, 3-methoxy-N, N-dimethylpropanamide, 3-ethoxy-N, N-dimethylpropanamide, 3-butoxy-N, N-Dimethylpropanamide, 1,3-dimethyl-2-imidazolidinone, ethylamyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethylene carbonate, propylene carbonate, diglime, 4-hydroxy- 4-Methyl-2-pentanone, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene Glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl Examples include ether. These may be used alone or in combination.

The polymer composition used in the present invention may contain components other than the above components (A) and (B). Examples thereof include solvents and compounds that improve film thickness uniformity and surface smoothness when the polymer composition is applied, compounds that improve the adhesion between the liquid crystal alignment film and the substrate, (C) amine compounds, and the like. However, it is not limited to this.

Specific examples of the solvent (poor solvent) for improving the uniformity of the film thickness and the surface smoothness include the following.
For example, isopropyl alcohol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol mono. Isopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether , Dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tri Propropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 1-hexanol, 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 monoacetate Ethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropionic acid Propyl, 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-monomethi Examples thereof include solvents having a low surface tension such as ruether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, and 2- (2-ethoxypropoxy) propanol.

These poor solvents may be used alone or in admixture of a plurality of types. When the above-mentioned solvent is used, it is preferably 5 to 80% by mass, more preferably 20% by mass, so as not to significantly reduce the solubility of the entire solvent contained in the polymer composition. ~ 60% by mass.

Examples of the compound for improving the uniformity of the film thickness and the surface smoothness include a fluorine-based surfactant, a silicone-based surfactant, and a nonion-based surfactant.
More specifically, for example, Ftop (registered trademark) 301, EF303, EF352 (manufactured by Mitsubishi Materials Electronics Chemical Co., Ltd.), Megafuck (registered trademark) F171, F173, R-30 (manufactured by DIC), Florard FC430, FC431 (3M Japan Ltd.), Asahi Guard (registered trademark) AG710 (AGC), Surflon (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, SC106 (AGC Seimi Chemical), etc. Can be mentioned. The ratio of these surfactants used is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, based on 100 parts by mass of the resin component contained in the polymer composition. ..

Specific examples of the compound that improves the adhesion between the liquid crystal alignment film and the substrate include the following functional silane-containing compounds.
For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane. , N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxy Carbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl- 1,4,7-Triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxy Examples thereof include silane and N-bis (oxyethylene) -3-aminopropyltriethoxysilane.

Furthermore, in addition to improving the adhesion between the substrate and the liquid crystal alignment film, the following phenoplast-based or epoxy group-containing compounds are added for the purpose of preventing deterioration of electrical characteristics due to the backlight when the liquid crystal display element is configured. The agent may be contained in the polymer composition. Specific phenoplast-based additives are shown below, but are not limited to this structure.

Specific epoxy group-containing compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-Hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N', N'-tetraglycidyl-m-xylene diamine, 1,3-bis (N, N-diglycidyl aminomethyl) cyclohexane, N, N, N', N'-tetraglycidyl-4, 4'-diaminodiphenylmethane, etc. Illustrated.

When a compound that improves adhesion to a substrate is used, the amount used is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the resin component contained in the polymer composition. It is preferably 1 to 20 parts by mass. If the amount used is less than 0.1 parts by mass, the effect of improving the adhesion cannot be expected, and if it is more than 30 parts by mass, the orientation of the liquid crystal may deteriorate.

<(C) Amine compound>
The polymer composition used in the present invention has a specific amine compound as the component (C), specifically, one primary amino group in the molecule and a nitrogen-containing aromatic heterocycle, and is described above. It can have an amine compound in which the primary amino group is attached to an aliphatic hydrocarbon group or a non-aromatic cyclic hydrocarbon group. Such a compound is described as a component (B) in WO2008 / 013285. By containing such an amine compound, elution of ionic impurities can be reduced when the liquid crystal alignment film is formed.
The specific amine compound is not particularly limited as long as it exhibits the following effects i) and / or ii) when the polymer composition used in the present invention forms a liquid crystal alignment film. i) Adsorbs ionic impurities in the liquid crystal at the liquid crystal alignment film interface and / or ii) exhibits an improved voltage retention rate.
The amount of the specific amine compound is not particularly limited as long as it exhibits the above effects, but is 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, out of 100 parts by mass of the polymer composition used in the present invention. It should be parts by mass.

A photosensitizer can also be used as the additive. Colorless sensitizers and triplet sensitizers are preferred.
Photosensitizers include aromatic nitro compounds, coumarins (7-diethylamino-4-methylcoumarin, 7-hydroxy-4-methylcoumarin), ketocoumarins, carbonylbiscoumarins, aromatic 2-hydroxyketones, and amino substitutions. Also, aromatic 2-hydroxyketone (2-hydroxybenzophenone, mono- or di-p- (dimethylamino) -2-hydroxybenzophenone), acetophenone, anthraquinone, xanthone, thioxanthone, benzanthron, thiazolin (2-benzoylmethylene-). 3-Methyl-β-naphthiazoline, 2- (β-naphthoylmethylene) -3-methylbenzothiazolin, 2- (α-naphthoylmethylene) -3-methylbenzothiazolin, 2- (4-biphenoylmethylene) -3-Methylbenzothiazolin, 2- (β-naphthoylmethylene) -3-methyl-β-naphthiazoline, 2- (4-biphenoylmethylene) -3-methyl-β-naphthiazoline, 2- (p- Fluorobenzoylmethylene) -3-methyl-β-naphthiazoline), oxazoline (2-benzoylmethylene-3-methyl-β-naphthoxazoline, 2- (β-naphthoylmethylene) -3-methylbenzoxazoline, 2-( α-Naftylmethylene) -3-methylbenzoxazoline, 2- (4-biphenoylmethylene) -3-methylbenzoxazoline, 2- (β-naphthoylmethylene) -3-methyl-β-naphthoxazoline, 2- (4-Bifenoylmethylene) -3-methyl-β-naphthoxazoline, 2- (p-fluorobenzoylmethylene) -3-methyl-β-naphthoxazoline), benzothiazole, nitroaniline (m- or p-nitroaniline) , 2,4,6-trinitroaniline) or nitroacenaften (5-nitroacenaften), (2-[(m-hydroxy-p-methoxy) styryl] benzothiazole, benzoin alkyl ether, N-alkylated phthalone , Acetphenon ketal (2,2-dimethoxyphenyletanone), naphthalene, anthracene (2-naphthalene methanol, 2-naphthalenecarboxylic acid, 9-anthracenemethanol, and 9-anthracenecarboxylic acid), benzopyrane, azoindrinsin, methylcoumarin And so on.
Preferred are aromatic 2-hydroxyketone (benzophenone), coumarin, ketocoumarin, carbonylbiscoumarin, acetophenone, anthraquinone, xanthone, thioxanthone, and acetophenone ketal.

In addition to the above-mentioned polymer compositions, dielectrics and conductive substances can be used for the purpose of changing the electrical properties such as the dielectric constant and conductivity of the liquid crystal alignment film as long as the effects of the present invention are not impaired. Further, a crosslinkable compound may be added for the purpose of increasing the hardness and the density of the film when the liquid crystal alignment film is formed.

The method of applying the above-mentioned polymer composition onto a substrate having an electrode for driving a liquid crystal is not particularly limited.
Industrially, the coating method is generally screen printing, offset printing, flexographic printing, an inkjet method, or the like. Other coating methods include a dip method, a roll coater method, a slit coater method, a spinner method (rotary coating method), a spray method, and the like, and these may be used depending on the purpose.

After the polymer composition is applied onto a substrate having electrodes for driving a liquid crystal, the temperature is 50 to 230 ° C., preferably 50 to 220 ° C. by a heating means such as a hot plate, a heat circulation type oven or an IR (infrared) type oven. The coating film can be obtained by evaporating the solvent for 0.4 to 60 minutes, preferably 0.5 to 10 minutes. The drying temperature at this time is preferably lower than the liquid crystal phase expression temperature of the side chain polymer.

If the thickness of the coating film is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may decrease. Therefore, the thickness is preferably 5 to 300 nm, more preferably 10 to 150 nm. Is.
It is also possible to provide a step of cooling the substrate on which the coating film is formed to room temperature after the step [I] and before the subsequent step [II].

<Step [II]>
In the step [II], the coating film obtained in the step [I] is irradiated with ultraviolet rays polarized so that the S wave is the main component from an oblique direction. When the film surface of the coating film is irradiated with polarized ultraviolet rays, the substrate is irradiated with polarized ultraviolet rays from a certain direction via a polarizing plate. As the ultraviolet rays to be used, ultraviolet rays having a wavelength in the range of 100 to 400 nm can be used. Preferably, the optimum wavelength is selected through a filter or the like depending on the type of coating film used. Then, for example, ultraviolet rays having a wavelength in the range of 290 to 400 nm can be selected and used so that the photocrosslinking reaction can be selectively induced. As the ultraviolet rays, for example, light emitted from a high-pressure mercury lamp can be used.

The irradiation amount of ultraviolet rays polarized so that the S wave is the main component depends on the coating film used. The irradiation amount is a polarized ultraviolet ray that realizes the maximum value of ΔA (hereinafter, also referred to as ΔAmax), which is the difference between the ultraviolet ray absorbance in the direction parallel to the polarization direction of the polarized ultraviolet rays and the ultraviolet ray absorbance in the vertical direction in the coating film. The amount is preferably in the range of 1 to 70%, and more preferably in the range of 1 to 50%.

The irradiation direction of the polarized ultraviolet rays is usually 1 ° to 89 ° with respect to the substrate, but is preferably 10 ° to 80 °, particularly preferably 20 ° to 70 °. If this angle is too small, there is a problem that the pre-tilt angle becomes small, and if it is too large, there is a problem that the pre-tilt angle becomes high.

As a method of adjusting the irradiation direction to the above angle, there are a method of tilting the substrate itself and a method of tilting the light beam, but tilting the light beam itself is more preferable from the viewpoint of the production throughput of the liquid crystal display element.

<Step [III]>
In step [III], the coating film irradiated with ultraviolet rays polarized in step [II] is heated. Orientation control ability can be imparted to the coating film by heating.
For heating, a heating means such as a hot plate, a heat circulation type oven, or an IR (infrared) type oven can be used. The heating temperature can be determined in consideration of the temperature at which the liquid crystal property of the coating film to be used is exhibited.

The heating temperature is preferably within the temperature range of the temperature at which the side chain polymer exhibits liquid crystallinity (hereinafter referred to as the liquid crystal expression temperature). In the case of a thin film surface such as a coating film, the liquid crystal development temperature on the coating film surface is expected to be lower than the liquid crystal development temperature when a photosensitive side chain polymer capable of exhibiting liquid crystal properties is observed in bulk. The liquid crystal. Therefore, the heating temperature is more preferably within the temperature range of the liquid crystal expression temperature on the surface of the coating film. That is, the temperature range of the heating temperature after irradiation with polarized ultraviolet rays is set to a temperature 10 ° C. lower than the lower limit of the temperature range of the liquid crystal expression temperature of the side chain polymer to be used, and is 10 ° C. lower than the upper limit of the liquid crystal temperature range. The temperature is preferably in the range up to. If the heating temperature is lower than the above temperature range, the effect of amplifying the anisotropy due to heat in the coating film tends to be insufficient, and if the heating temperature is too high above the above temperature range, the state of the coating film is in a state. Tends to be close to an isotropic liquid state (isotropic phase), in which case self-assembly can make it difficult to reorient in one direction.
The liquid crystal development temperature is equal to or higher than the glass transition temperature (Tg) at which the side chain polymer or the coating surface undergoes a phase transition from the solid phase to the liquid crystal phase, and the liquid crystal phase changes to the isotropic phase (isotropic phase). The temperature below the isotropic phase transition temperature (Tiso) that causes a phase transition.

The thickness of the coating film formed after heating is preferably 5 to 300 nm, more preferably 50 to 150 nm for the same reason described in step [I].

By having the above steps, the production method of the present invention can realize highly efficient introduction of anisotropy into the coating film. Then, a substrate with a liquid crystal alignment film can be manufactured with high efficiency.

<Step [IV]>
In step [IV], the substrate obtained in the two steps [III] arranged so that the sides on which the liquid crystal alignment film of the substrate was formed face each other, the liquid crystal layer provided between the substrates, and the substrate and the liquid crystal. This is a step of producing a liquid crystal display element including a liquid crystal cell having the liquid crystal alignment film provided between the layers and formed by the liquid crystal alignment agent of the present invention. Such liquid crystal display elements of the present invention include a twisted nematic (TN: Twisted Nematic) method, a vertical alignment (VA: Vertical Alignment) method, a horizontal alignment (IPS: In-Plane Switching) method, and an OCB alignment (OCB:). Optically Compensated Bend) and the like.

To give an example of manufacturing a liquid crystal cell or a liquid crystal display element, the above-mentioned first and second substrates are prepared, a spacer is sprayed on the liquid crystal alignment film of one of the substrates, and the liquid crystal alignment film surface is on the inside. In this way, the other substrate is bonded so that the ultraviolet exposure directions are orthogonal to each other, and the liquid crystal is injected under reduced pressure to seal the liquid crystal, or the liquid crystal is dropped on the liquid crystal alignment film surface on which the spacer is sprayed, and then the substrate is used. Can be exemplified, such as a method of laminating and sealing. The diameter of the spacer at this time is preferably 1 to 30 μm, more preferably 2 to 10 μm. This spacer diameter determines the distance between the pair of substrates sandwiching the liquid crystal layer, that is, the thickness of the liquid crystal layer.

It is preferable that the obtained liquid crystal display element is further annealed for orientation stability. The heating temperature is the phase transition temperature of the liquid crystal, preferably 10 to 160 ° C, more preferably 50 to 140 ° C.

In the method for producing a coated substrate of the present invention, the polymer composition is applied onto the substrate to form a coating film, and then polarized ultraviolet rays are irradiated from an oblique direction. Next, by heating, highly efficient anisotropy is introduced into the side chain type polymer film, and a substrate with a liquid crystal alignment film having a liquid crystal orientation control ability is manufactured.
The coating film used in the present invention realizes the introduction of highly efficient anisotropy into the coating film by utilizing the principle of molecular reorientation induced by the photoreaction of side chains and self-assembly based on liquid crystallinity. .. In the production method of the present invention, in the case of a structure having a photocrosslinkable group as a photoreactive group in the side chain polymer, after forming a coating film on the substrate using the side chain polymer, polarized ultraviolet rays are emitted. After irradiating and then heating, a liquid crystal display element is produced.

Therefore, the coating film used in the method of the present invention is a liquid crystal alignment film having excellent orientation control ability because anisotropy is introduced with high efficiency by sequentially irradiating the coating film with polarized ultraviolet rays and heat treatment. can do.

Then, in the coating film used in the method of the present invention, the irradiation amount and irradiation direction of polarized ultraviolet rays on the coating film and the heating temperature in the heat treatment are optimized. As a result, highly efficient introduction of anisotropy into the coating film can be realized.

The optimum irradiation amount of polarized ultraviolet rays for introducing highly efficient anisotropy into the coating film used in the present invention is the irradiation amount of polarized ultraviolet rays that optimizes the amount of photoisomerization reaction of photosensitive groups in the coating film. Corresponds to. As a result of irradiating the coating film used in the present invention with polarized ultraviolet rays, if the number of photosensitive groups in the side chain undergoing photoisomerization reaction is small, the amount of photoreaction is not sufficient. In that case, even if it is heated after that, sufficient self-organization does not proceed.

Therefore, in the coating film used in the present invention, the optimum amount of photoisomerization reaction of the photosensitive groups of the side chain by irradiation with polarized ultraviolet rays is 0.1 to 0.1 to 0.1 to the photosensitive groups of the side chain type polymer film. It is preferably 40 mol%, more preferably 0.1 to 20 mol%. By setting the amount of photosensitive groups in the side chain that photoreacts in such a range, self-assembly in the subsequent heat treatment proceeds efficiently, and highly efficient anisotropy can be formed in the film. Become.

In the coating film used in the method of the present invention, the amount of photoisomerization reaction of the photosensitive group in the side chain of the side chain type polymer film is optimized by optimizing the irradiation amount of polarized ultraviolet rays. Then, in combination with the subsequent heat treatment, highly efficient introduction of anisotropy into the coating film used in the present invention is realized. In that case, the suitable amount of polarized ultraviolet rays can be determined based on the evaluation of ultraviolet absorption of the coating film used in the present invention.

That is, for the coating film used in the present invention, the ultraviolet absorption in the direction parallel to the polarization direction of the polarized ultraviolet rays and the ultraviolet absorption in the vertical direction after irradiation with polarized ultraviolet rays are measured, respectively. From the measurement result of ultraviolet absorption, ΔA, which is the difference between the ultraviolet absorbance in the direction parallel to the polarization direction of the polarized ultraviolet rays and the ultraviolet absorbance in the direction perpendicular to the polarization direction, is evaluated. Then, the maximum value (ΔAmax) of ΔA realized in the coating film used in the present invention and the irradiation amount of polarized ultraviolet rays to realize it are obtained. In the production method of the present invention, a preferable amount of polarized ultraviolet rays to be irradiated in the production of the liquid crystal alignment film can be determined based on the amount of polarized ultraviolet rays that realizes this ΔAmax.

In the production method of the present invention, the irradiation amount of polarized ultraviolet rays on the coating film used in the present invention is preferably in the range of 1 to 70% of the amount of polarized ultraviolet rays that realize ΔAmax, and 1 to 50%. It is more preferable that the content is within the range of. In the coating film used in the present invention, the irradiation amount of polarized ultraviolet rays in the range of 1 to 50% of the amount of polarized ultraviolet rays that realize ΔAmax is 0.1 of the entire photosensitive groups of the side chain type polymer film. Corresponds to the amount of polarized ultraviolet light that photocrosslinks up to 20 mol%.

Based on the above, in the production method of the present invention, in order to realize highly efficient introduction of anisotropy into the coating film, the suitable heating temperature as described above is set based on the liquid crystal temperature range of the side chain polymer. It is better to determine. Therefore, for example, when the liquid crystal temperature range of the side chain polymer used in the present invention is 100 to 200 ° C., it is desirable that the heating temperature after irradiation with polarized ultraviolet rays is 90 to 190 ° C. By doing so, the coating film used in the present invention is imparted with greater anisotropy. By doing so, the liquid crystal display element provided by the present invention exhibits high reliability against external stress such as light and heat.

As described above, the liquid crystal display element substrate or the liquid crystal display element having the substrate manufactured by the method of the present invention has excellent reliability and orientation stability, and is a large-screen, high-definition liquid crystal television or the like. Can be suitably used for.
Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited to these Examples.

The abbreviations used in the examples are as follows.
<Methyl monomer>

MA-1 was synthesized by the synthetic method described in Patent Document (WO2011-084546).
MA-2 was synthesized by the synthetic method described in Patent Document (Japanese Patent Laid-Open No. 9-118717).
MA-3 and MA-4 were synthesized by the synthetic method described in Patent Document (WO2011-125876).
MA-6 was synthesized by the synthetic method described in the international patent application publication WO2014 / 054785 pamphlet.
MA-7 was synthesized by the synthetic method described in the non-patent document (Macromolecules 2007, 40, 6355-6360).
MA-8 was synthesized by the synthetic method described in the non-patent document (Macromolecules 2002, 35, 706-713).
MA-10 was synthesized by the synthetic method described in Patent Document (Japanese Patent Laid-Open No. 9-118717).
MA-11 was synthesized by the synthetic method described in Patent Document (WO2017-018501).
MA-12 was purchased from Tokyo Chemical Industry Co., Ltd. and used.
MA-13 was purchased from Tokyo Chemical Industry Co., Ltd. and used.

<Organic solvent>
NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve THF: tetrahydrofuran DMF: N, N-dimethylformamide PhMe: Toluene EtOH: Ethanol

<Polymerization initiator>
AIBN: 2,2'-azobisisobutyronitrile

< ¹ HNMR measurement>
Device: Fourier transform type superconducting nuclear magnetic resonance device (FT-NMR) "AVANCE III" (manufactured by BRUKER) 500 MHz.
Solvent: Deuterated chloroform (CDCl ₃ ) or deuterated N, N-dimethyl sulfoxide ([D ₆ ] -DMSO).
Standard substance: Tetramethylsilane (TMS).

<Methyl compound>
MA-5 is a novel compound which has not been published in the literature, and its synthesis method will be described in detail in the following Monomer Synthesis Example 1.

4-Hydroxy-4'-iodobiphenyl (25.2 g: 85 mmol), 1-bromopropane (12.6 g: 102 mmol), potassium carbonate (17.6 g: 128 mmol), DMF (250 g) in a 1 L four-necked flask. It was charged and stirred at 80 ° C. After completion of the reaction, the reaction solution was poured into pure water (1500 g), and the precipitate was filtered off. Ethyl acetate (30 g) and hexane (20 g) were added to the obtained crude product, and repulp washing was performed at room temperature to obtain 21.8 g of [MA-5-1].

[MA-5-1] (21.8 g: 64 mmol), 2-propin-1-ol (5.0 g: 90 mmol), triethylamine (13.0 g: 129 mmol), THF (220 g) are placed in a 1 L four-necked flask. After preparation and nitrogen substitution, bis (triphenylphosphine) palladium (II) dichloride (4.5 g: 6 mmol) and copper (I) iodide (1.2 g: 6 mmol) were added, and the mixture was stirred at room temperature. After completion of the reaction, the precipitate was filtered and the filtrate was concentrated. Ethyl acetate (400 g) was added to the obtained residue, and the organic layer was washed with 1N-hydrochloric acid aqueous solution (500 g), saturated sodium hydrogen carbonate aqueous solution (500 g), and pure water (500 g), and then concentrated. The obtained crude product was subjected to origin cutting with silica gel using an ethyl acetate / hexane (volume ratio 1: 3) solution, and then hexane (700 g) was added to the obtained crude product and washed with repulp at room temperature. By doing so, 13.6 g of [MA-5-2] was obtained.

[MA-5-2] (13.6 g: 51 mmol), THF (100 g), EtOH (100 g) were charged in a 300 mL four-necked flask, nitrogen was replaced, 5% Pd / C was added, and hydrogen was replaced at room temperature. Was stirred with. After completion of the reaction, Pd / C was removed by filtering the reaction solution with a membrane filter. The obtained crude product is subjected to origin cutting with silica gel using an ethyl acetate / hexane (volume ratio 1:10) solution, and hexane (50 g) is further added to the obtained crude product and repulp-washed at room temperature. Then, 5.6 g of [MA-5-3] was obtained.

[MA-5-3] (5.6 g: 21 mmol), methacrylic acid (2.2 g: 25 mmol), p-toluenesulfonic acid monohydrate (0.6 g: 3 mmol), 2, in a 300 mL four-necked flask. 6-di-tert-butyl-p-cresol (0.05 g: 0.2 mmol) and PhMe (60 g) were charged and stirred in a reflux state using a Dean-Stark apparatus. After completion of the reaction, the reaction solution was poured into ethyl acetate (200 g), washed with 10 mass% potassium carbonate aqueous solution (300 g) and pure water (300 g), and then concentrated. The obtained residue was cut off from the origin with silica gel using an ethyl acetate / hexane (volume ratio 1:10) solution, and hexane (30 g) was added to the obtained crude product and repulp washed at room temperature. 2.9 g of [MA-5] (yellow solid) was obtained. The results of 1H-NMR of the target product are shown below. From this result, it was confirmed that the obtained solid was the target [MA-5].
1H NMR (500 MHz, [D ₆ ] -DMSO): δ7.51-7.56 (q, 4H), 7.25-7.27 (d, 2H), 6.98-7.00 (d, 2H), 6.03 (s, 1H), 5.67 (s, 1H), 4.10-4.12 (t, 2H), 3.94-3.97 (t, 2H), 2.68-2.71 (m, 2H), 1.94-1.99 (m, 2H), 1.93 (s, 3H), 1.71-1.78 (m, 2H), 0.98-1.00 (t, 3H)

<Synthesis Example 1: Methacrylic Polymer>
MA-1 (10 g: 30 mmol), MA-2 (15 g: 50 mmol), MA-3 (8 g: 20 mmol) were dissolved in NMP (227 g), degassed with a diaphragm pump, and then AIBN (0. 5 g: 3 mmol) was added and degassing was performed again. Then, the reaction was carried out at 60 ° C. for 6 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to methanol (2000 mL) and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain methacrylate polymer powder P1.

<Synthesis Example 2: Methacrylic Polymer>
MA-1 (10 g: 30 mmol), MA-2 (15 g: 50 mmol), MA-4 (9 g: 20 mmol) were dissolved in NMP (233 g), degassed with a diaphragm pump, and then AIBN (0. 5 g: 3 mmol) was added and degassing was performed again. Then, the reaction was carried out at 60 ° C. for 6 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to methanol (2000 mL) and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain methacrylate polymer powder P2.

<Synthesis Example 3: Methacrylic Polymer>
MA-1 (10 g: 30 mmol), MA-2 (15 g: 50 mmol), and MA-5 (7 g: 20 mmol) were dissolved in NMP (219 g), degassed with a diaphragm pump, and then AIBN (0. 5 g: 3 mmol) was added and degassing was performed again. Then, the reaction was carried out at 60 ° C. for 6 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to methanol (2000 mL) and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain methacrylate polymer powder P3.

<Synthesis Example 4: Methacrylic Polymer>
Dissolve MA-1 (10 g: 30 mmol), MA-2 (15 g: 50 mmol), MA-3 (8 g: 20 mmol), MA-9 (0.2 g: 1 mmol) in NMP (229 g) and use a diaphragm pump. After degassing, AIBN (0.5 g: 3 mmol) was added and degassed again. Then, the reaction was carried out at 60 ° C. for 6 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to methanol (2000 mL) and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P4.

<Synthesis Example 5: Methacrylic Polymer>
MA-1 (10 g: 30 mmol), MA-2 (12 g: 40 mmol), MA-3 (8 g: 20 mmol), MA-10 (4 g: 10 mmol) are dissolved in NMP (230 g) and degassed with a diaphragm pump. After that, AIBN (0.5 g: 3 mmol) was added and degassing was performed again. Then, the reaction was carried out at 60 ° C. for 6 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to methanol (2000 mL) and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P5.

<Synthesis Example 6: Methacrylic Polymer>
MA-1 (10 g: 30 mmol), MA-2 (9 g: 30 mmol), MA-3 (8 g: 20 mmol), MA-10 (7 g: 20 mmol) are dissolved in NMP (232 g) and degassed with a diaphragm pump. After that, AIBN (0.5 g: 3 mmol) was added and degassing was performed again. Then, the reaction was carried out at 60 ° C. for 6 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to methanol (2000 mL) and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P6.

<Synthesis Example 7: Methacrylic Polymer>
MA-6 (16 g: 30 mmol), MA-2 (15 g: 50 mmol), MA-3 (8 g: 20 mmol) were dissolved in NMP (265 g), degassed with a diaphragm pump, and then AIBN (0. 5 g: 3 mmol) was added and degassing was performed again. Then, the reaction was carried out at 60 ° C. for 6 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to methanol (2000 mL) and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P7.

<Synthesis Example 8: Methacrylic Polymer>
MA-7 (17 g: 30 mmol), MA-2 (15 g: 50 mmol), MA-3 (8 g: 20 mmol) were dissolved in NMP (275 g), degassed with a diaphragm pump, and then AIBN (0. 5 g: 3 mmol) was added and degassing was performed again. Then, the reaction was carried out at 60 ° C. for 6 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to methanol (2000 mL) and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P7.

<Synthesis Example 9: Methacrylic Polymer>
MA-8 (15 g: 30 mmol), MA-2 (15 g: 50 mmol), MA-3 (8 g: 20 mmol) were dissolved in NMP (263 g), degassed with a diaphragm pump, and then AIBN (0. 5 g: 3 mmol) was added and degassing was performed again. Then, the reaction was carried out at 60 ° C. for 6 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to methanol (2000 mL) and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P9.

<Synthetic Example 10: Methacrylic Polymer>
MA-1 (13 g: 40 mmol) and MA-2 (18 g: 60 mmol) are dissolved in NMP (217 g), degassed with a diaphragm pump, and then AIBN (0.5 g: 3 mmol) is added and degassed again. Was done. Then, the reaction was carried out at 60 ° C. for 6 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to methanol (2000 mL) and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P10.

<Synthetic Example 11: Methacrylic Polymer>
MA-2 (15 g: 50 mmol), MA-3 (4 g: 10 mmol), MA-11 (22 g: 50 mmol) were dissolved in NMP (280 g), degassed with a diaphragm pump, and then AIBN (0. 5 g: 3 mmol) was added and degassing was performed again. Then, the reaction was carried out at 60 ° C. for 6 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to methanol (2000 mL) and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P11.

<Synthetic Example 12: Methacrylic Polymer>
MA-2 (15 g: 50 mmol), MA-4 (4 g: 10 mmol), MA-11 (22 g: 50 mmol) were dissolved in NMP (282 g), degassed with a diaphragm pump, and then AIBN (0. 5 g: 3 mmol) was added and degassing was performed again. Then, the reaction was carried out at 60 ° C. for 6 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to methanol (2000 mL) and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P12.

<Synthesis Example 13: Methacrylic Polymer>
MA-2 (15 g: 50 mmol), MA-12 (2 g: 10 mmol), and MA-11 (22 g: 50 mmol) were dissolved in NMP (265 g), degassed with a diaphragm pump, and then AIBN (0. 5 g: 3 mmol) was added and degassing was performed again. Then, the reaction was carried out at 60 ° C. for 6 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to methanol (2000 mL) and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P13.

<Synthetic Example 14: Methacrylic Polymer>
MA-2 (15 g: 50 mmol), MA-13 (4 g: 15 mmol), and MA-11 (22 g: 50 mmol) were dissolved in NMP (279 g), degassed with a diaphragm pump, and then AIBN (0. 5 g: 3 mmol) was added and degassing was performed again. Then, the reaction was carried out at 60 ° C. for 6 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to methanol (2000 mL) and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P14.

<Preparation of liquid crystal alignment agent: A1>
NMP (8.1 g) was added to the methacrylate polymer powder P1 (0.9 g) obtained in Synthesis Example 1 above, and the mixture was dissolved by stirring at room temperature for 1 hour. BCS (6.0 g) was added to this solution to obtain a polymer solution (A1) having a solid content concentration of 6.0% by mass. This polymer solution serves as a liquid crystal alignment agent for forming a liquid crystal alignment film as it is.

For the liquid crystal alignment agents A2 to 9 and B1 to 5 under the conditions shown in Table 1, liquid crystal alignment agents were prepared by using the same method as the liquid crystal alignment agents A1.

<Creation of substrate for in-plane order parameter measurement>
Using the liquid crystal alignment agent obtained above, a substrate for measuring the photoreaction rate was prepared by the procedure shown below. As the substrate, a quartz substrate having a size of 40 mm × 40 mm and a thickness of 1.0 mm was used. The liquid crystal alignment agent A1 was filtered through a filter having a filter pore size of 1.0 μm, spin-coated on a quartz substrate, and dried on a hot plate at 70 ° C. for 90 seconds to form a liquid crystal alignment film having a film thickness of 100 nm.

(Example 1)
After tilting the coating film surface by 45 ° and irradiating the substrate with S-wave 313 nm ultraviolet rays at 40 mJ / cm ² through a polarizing plate, the substrate with a liquid crystal alignment film that has been photoreacted is heated on a hot plate at 130 ° C. for 20 minutes. Obtained.

For Examples 2 to 9 and Comparative Examples 1 to 5 under the conditions shown in Table 2, substrates for measuring the degree of in-plane orientation were prepared by using the same method as in Example 1.

<Measurement of in-plane orientation>
In order to measure the optical anisotropy of the liquid crystal alignment film using the substrate with the liquid crystal alignment film prepared above, S, which is the in-plane orientation degree, was calculated from the absorbance of polarized light from the following formula. The calculated value used was the highest value within the irradiation dose range.
An ultraviolet-visible-near-infrared analysis photometer U-3100PC manufactured by Shimadzu Corporation was used for the measurement of the absorbance.

Here, A _para represents the absorbance in the direction parallel to the irradiated polarized UV direction, and A _per represents the absorbance in the direction perpendicular to the irradiated polarized UV direction. A _large represents the absorbance having a larger value by comparing the absorbances in the parallel direction and the vertical direction, and A _small represents the absorbance having a smaller value by comparing the absorbances in the parallel direction and the vertical direction. The closer the absolute value of the in-plane orientation is to 1, the more uniform the orientation is.

As shown in Table 2, it can be seen that when the liquid crystal alignment agents of Examples 1 to 9 are used, the degree of orientation in the direction perpendicular to the polarized UV direction is high. When the liquid crystal alignment agents of Comparative Examples 2 to 5 are used, the degree of orientation in the direction parallel to the polarized UV direction is high. This is due to whether the photoreaction of the photosensitive group is derived from isomerization or dimerization.

<Manufacturing of liquid crystal cell>
The liquid crystal alignment agent (A1) was filtered through a 0.45 μm filter, spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at 70 ° C. for 90 seconds, and then a liquid crystal alignment film having a film thickness of 100 nm was formed. ..

(Example 10)
The coating film surface was tilted by 45 °, and after irradiating the substrate with S-wave 313 nm ultraviolet rays ^{2 at} 40 mJ / cm ² through a polarizing plate, the substrate was heated on a hot plate at 130 ° C. for 20 minutes to obtain a substrate with a liquid crystal alignment film. Two such substrates with a liquid crystal alignment film are prepared, a spacer of 4 μm is installed on the liquid crystal alignment film surface of one of the substrates, and then the two substrates are combined so that the orientation directions are parallel to each other. The periphery was sealed leaving the above, and an empty cell having a cell gap of 4 μm was prepared. Liquid crystal MLC-3018 (manufactured by Merck & Co., Inc.) was injected into this empty cell by a vacuum injection method, and the injection port was sealed to obtain an anti-parallel liquid crystal cell.

For Examples 11 to 18 and Comparative Examples 6 to 10 under the conditions shown in Table 3, liquid crystal cells were prepared by the same method as in Example 10.

(Comparative Example 11)
The coating film surface was tilted by 40 °, and after irradiating the substrate with P-wave 313 nm ultraviolet rays ^{2 at} 80 mJ / cm ² through a polarizing plate, the substrate was heated on a hot plate at 210 ° C. for 20 minutes to obtain a substrate with a liquid crystal alignment film. Two such substrates with a liquid crystal alignment film are prepared, a spacer of 4 μm is installed on the liquid crystal alignment film surface of one of the substrates, and then the two substrates are combined so that the orientation directions are parallel to each other. The surrounding area was sealed, leaving a cell gap of 4 μm to prepare an empty cell. Liquid crystal MLC-3018 (manufactured by Merck & Co., Inc.) was injected into this empty cell by a vacuum injection method, and the injection port was sealed to obtain an anti-parallel liquid crystal cell.

For Comparative Examples 12 to 14 under the conditions shown in Table 3, liquid crystal cells were prepared by the same method as in Comparative Example 11.

(Pre-tilt angle)
After the liquid crystal display element obtained above is subjected to isotropic treatment by heating at a temperature of 120 ° C. for 30 minutes, the pretilt angle of the liquid crystal cell is measured by the Mueller matrix method using AxoScan manufactured by Axometrics. did. The evaluation results are shown in Table 3.

(Evaluation of orientation stability)
The liquid crystal cell was backlit for 336 hours in an environment of 25 ° C., and the pretilt angle before and after stress was measured. The measurement results were calculated and evaluated based on the following formula. The evaluation results are shown in Table 3.

As shown in Table 3, when the liquid crystal alignment agents of Examples 10 to 18 were used, it was possible to obtain a liquid crystal pretilt angle suitable for the twist nematic mode and OCB. In addition, the orientation stability after stress is high. This is because a polymer having an in-plane orientation-inducing site and an out-of-plane orientation-inducing site in different side chains is used, that is, in-plane orientation and pretilt angle formation are functionally separated. It is considered that it is derived from doing.

Claims

(A) A weight having a portion that induces in-plane orientation in a direction (S-wave direction) perpendicular to the parallel direction (P-wave direction) of polarized ultraviolet rays and a portion that induces out-of-plane orientation in different side chains. A polymer composition containing a coalescence and (B) an organic solvent.
The composition according to claim 1, wherein the site that induces in-plane orientation is a site that causes photoisomerization.
The side chains having sites that induce in-plane orientation are represented by the following equations (1) to (3).
(In the formula, A, B and D independently represent single bonds, -O-, -CH 2- , -COO-, -OCO-, -CONH- or -NH-CO-;
S is an alkylene group having 1 to 12 carbon atoms, and the hydrogen atom of the alkylene group may be independently replaced with a halogen atom;
T is a single bond or an alkylene group having 1 to 12 carbon atoms, and the hydrogen atom of the alkylene group may be replaced with a halogen atom;
When T is a single bond, B also represents a single bond;
Y 1 is a divalent benzene ring;
P 1 , Q 1 and Q 2 are groups independently selected from the group consisting of a benzene ring and an alicyclic hydrocarbon ring having 5 to 8 carbon atoms, respectively;
R 1 is a hydrogen atom, -CN, a halogen atom, an alkyl group having 1 to 5 carbon atoms, a carbonyl group (alkyl having 1 to 5 carbon atoms), a cycloalkyl group having 3 to 7 carbon atoms, or an alkyl group having 1 to 5 carbon atoms. It is an alkyloxy group.
In Y 1 , P 1 , Q 1 and Q 2 , the hydrogen atom bonded to the benzene ring is independently -CN, a halogen atom, an alkyl group having 1 to 5 carbon atoms, and a (alkyl having 1 to 5 carbon atoms) carbonyl group. , Or may be substituted with an alkyloxy group having 1 to 5 carbon atoms;
X 1 and X 2 independently represent -O-, -COO- or -OCO-;
n1 and n2 are 0, 1 or 2, respectively.
When the number of X 1 is 2, X 1 together may be the same or different, when the number of X 2 is 2, X 2 together may be the same or different;
When the number of Q 1 is a 2, Q 1 each other may be the same or different, when the number Q 2 'is 2, Q 2 together may be the same or different;
The broken line represents the bond with the polymerizable group. )
The polymer composition according to claim 1 or 2, which is a side chain having a structure represented by a formula selected from the group consisting of.
A liquid crystal alignment film formed from the polymer composition according to any one of claims 1 to 3.
A substrate having the liquid crystal alignment film according to claim 4.
A liquid crystal display element having the substrate according to claim 5.
[I] A step of applying the polymer composition according to any one of claims 1 to 3 onto a substrate having an electrode for driving a liquid crystal to form a coating film;
[II] The step of irradiating the coating film obtained in [I] with ultraviolet rays polarized so that the S wave is the main component from an oblique direction; and [III] The coating film obtained in [II] is heated. Process;
A method for producing a substrate having the liquid crystal alignment film, which obtains a liquid crystal alignment film to which the orientation control ability is imparted.
The step of preparing the substrate (first substrate) according to claim 5;
[I'] A step of applying the polymer composition according to any one of claims 1 to 3 on a second substrate to form a coating film;
[II'] The step of irradiating the coating film obtained in [I'] with ultraviolet rays polarized so that the S wave is the main component; and heating the coating film obtained in [III'] [II']. Process to do;
A step of obtaining a second substrate having the liquid crystal alignment film, which obtains a liquid crystal alignment film to which the orientation control ability is imparted by having the liquid crystal alignment film; and [IV] the liquid crystal alignment film of the first and second substrates via the liquid crystal. A step of obtaining a liquid crystal display element by arranging the first and second substrates facing each other so that the exposure directions are orthogonal to each other so as to face each other;
A method for manufacturing a liquid crystal display element, wherein the liquid crystal display element is obtained.