JP2017082140A - Liquid crystal orientation agent, liquid crystal orientation film, and liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a liquid crystal orientation film in which orientation control ability is imparted with high efficiency and that has an excellent burn-in characteristic; a polymer composition that produces the same; and a lateral electric field driven type liquid crystal display element.SOLUTION: Provided is: a polymer composition containing (A) a photosensitive side-chain type polymer that exhibits liquid crystallinity in a predetermined temperature range, (B) heteropoly acid, and (C) organic solvent; and a process for producing a substrate having liquid crystal orientation film including steps of forming a coating film by applying said composition on a substrate having lateral electric field drive conductive film, irradiating polarized ultraviolet ray to thus produced coating film, and heating thus produced coating film.SELECTED DRAWING: None

Description

  The present invention relates to a novel liquid crystal aligning agent, a liquid crystal alignment film obtained therefrom, and a liquid crystal display element having the same. The liquid crystal display element obtained by the present invention is excellent in electrical characteristics.

  The liquid crystal display element is known as a light, thin and low power consumption display device, and has been remarkably developed in recent years. The liquid crystal display element is configured, for example, by sandwiching a liquid crystal layer between 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 alignment state between the substrates.

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

  A rubbing method is conventionally known as an alignment treatment method for a liquid crystal alignment film for imparting alignment control ability. The rubbing method is a method of rubbing (rubbing) 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 the rubbing direction (rubbing direction). This is a method of aligning liquid crystals. Since this rubbing method can easily realize a relatively stable alignment state of liquid crystals, it has been used in the manufacturing process of conventional liquid crystal display elements. As an organic film used for the liquid crystal alignment film, a polyimide-based organic film excellent in reliability such as heat resistance and electrical characteristics has been mainly selected.

  However, in the rubbing method of rubbing the surface of the liquid crystal alignment film made of polyimide or the like, generation of dust or static electricity may be a problem. In addition, due to the high definition of the liquid crystal surface element in recent years and the unevenness caused by the corresponding electrodes on the substrate and the switching active element for driving the liquid crystal, the surface of the liquid crystal alignment film cannot be uniformly rubbed with a cloth. In some cases, alignment of the liquid crystal could not be realized.

  Therefore, a photo-alignment method has been actively studied as another alignment treatment method for a liquid crystal alignment film that is not rubbed.

  There are various photo alignment methods. Anisotropy is formed in the organic film constituting the liquid crystal alignment film by linearly polarized light or collimated light, and the liquid crystal is aligned according to the anisotropy.

  A decomposition type photo-alignment method is known as a main photo-alignment method. In this method, for example, a polyimide film is irradiated with polarized ultraviolet rays, and anisotropic decomposition is caused by utilizing the polarization direction dependency of ultraviolet absorption of the molecular structure. Then, the liquid crystal is aligned by the polyimide remaining without being decomposed (see, for example, Patent Document 1).

  As other photo-alignment methods, photocrosslinking type and photoisomerization type photo-alignment methods are also known. In the photo-crosslinking type photo-alignment method, for example, polyvinyl cinnamate is used and irradiated with polarized ultraviolet rays to cause a dimerization reaction (cross-linking reaction) at double bond portions of two side chains parallel to the polarized light. Then, the liquid crystal is aligned in a direction orthogonal to the polarization direction (see, for example, Non-Patent Document 1). In the photoisomerization type photo-alignment method, when a side chain type polymer having azobenzene in the side chain is used, polarized ultraviolet light is irradiated to cause an isomerization reaction in the azobenzene portion of the side chain parallel to the polarized light. The liquid crystal is aligned in a direction orthogonal to the direction (see, for example, Non-Patent Document 2).

  As in the above example, the liquid crystal alignment film alignment treatment method by the photo alignment method eliminates the need for rubbing, and there is no fear of generation of dust or static electricity. An alignment process can be performed even on a substrate of a liquid crystal display element having an uneven surface, which is a method for aligning a liquid crystal alignment film suitable for an industrial production process.

Japanese Patent No. 3893659

M.M. Shadt et al. , Jpn. J. et al. Appl Phys. 31, 155 (1992) K. Ichimura et al. , Chem. Rev. 100, 1847 (2000)

  As described above, the photo-alignment method has a great advantage because it eliminates the rubbing process itself as compared with the rubbing method conventionally used industrially as an alignment treatment method for liquid crystal display elements. And compared with the rubbing method in which the alignment control ability becomes almost constant by rubbing, the photo alignment method can control the alignment control ability by changing the irradiation amount of polarized light. However, the photo-alignment method may require a large amount of polarized light irradiation to achieve the same degree of alignment control ability as the rubbing method, and stable liquid crystal alignment cannot be realized. There is.

  For example, in the decomposition type photo-alignment method described in Patent Document 1, it is necessary to irradiate the polyimide film with ultraviolet light from a high-pressure mercury lamp with an output of 500 W for 60 minutes. Become. Even in the case of a dimerization type or photoisomerization type photo-alignment method, a large amount of ultraviolet irradiation of about several J (joule) to several tens of J may be required.

  Therefore, in the photo-alignment method, there is a demand for higher efficiency of alignment treatment and realization of stable liquid crystal alignment, and liquid crystal alignment films and liquid crystals that can impart high alignment control ability to the liquid crystal alignment film with high efficiency. There is a need for aligning agents.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal alignment film for a liquid crystal display element, which has high efficiency and alignment control ability and is excellent in electrical characteristics, and a liquid crystal display element. Another object of the present invention is to provide a liquid crystal aligning agent that provides a liquid crystal aligning film having an improved voltage holding ratio.

As a result of intensive studies to achieve the above problems, the present inventors have found the following invention.
<1> [I] (A) Photosensitive side chain polymer that exhibits liquid crystallinity in a predetermined temperature range;
(B) A polymer composition containing a heteropolyacid, and (C) an organic solvent.

<2> In the above item <1>, the component (A) preferably has a photosensitive side chain that causes photocrosslinking, photoisomerization, or photofleece transition.
<3> In the above item <1> or <2>, the heteropolyacid may be phosphotungstic acid.
<4> In any one of the above items <1> to <3>, the component (A) may further have a side chain represented by the following formula (0).

In the formula, A and B are each independently a single bond, —O—, —CH ₂ —, —COO—, —OCO—, —CONH—, —NH—CO—, —CH═CH—CO—O—. Or -O-CO-CH = CH-;
S is an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced by a halogen group;
T is a single bond or an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced with a halogen group;
X is a single bond, —COO—, —OCO—, —N═N—, —CH═CH—, —C≡C—, —CH═CH—CO—O—, or —O—CO—CH═. When CH is 2 and the number of X is 2, X may be the same or different;
P and Q are each independently selected from the group consisting of a divalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof. Provided that when X is —CH═CH—CO—O— or —O—CO—CH═CH—, P or Q on the side to which —CH═CH— is bonded is an aromatic ring;
l1 is 0 or 1;
l2 is an integer from 0 to 2;
when l1 and l2 are both 0, A represents a single bond when T is a single bond;
when l1 is 1, B represents a single bond when T is a single bond;
G represents the following formulas (G-1), (G-2), (G-3) and (G-4).

(In the formula, a broken line represents a bond, R ⁵⁰ represents a group selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a phenyl group, and when there are a plurality of R ^50, they are the same or different from each other. T is an integer of 1 to 7, J represents O, S, NH or NR ⁵¹ , and R ⁵¹ represents a group selected from an alkyl group having 1 to 3 carbon atoms and a phenyl group). Group.
<5> In any one of the above items <1> to <4>, the component (A) may further have a side chain (b-2) having a group selected from a pyridyl group, an amide group, and a urethane group.
<6> In any one of the above items <1> to <5>, the component (A) has any one photosensitive side chain selected from the group consisting of the following formulas (1) to (6). Good.

In the formula, A, B, and D are each independently a single bond, —O—, —CH ₂ —, —COO—, —OCO—, —CONH—, —NH—CO—, —CH═CH—CO—. Represents O— or —O—CO—CH═CH—;
S is an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced by a halogen group;
T is a single bond or an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced with a halogen group;
Y ₁ represents a ring selected from a monovalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring and alicyclic hydrocarbon having 5 to 8 carbon atoms, or the same or selected from those substituents. 2 to 6 different rings are groups bonded through a bonding group B, and the hydrogen atoms bonded to them are each independently —COOR ₀ (wherein R ₀ is a hydrogen atom or a carbon number of 1 to 5 represents an alkyl group), —NO ₂ , —CN, —CH═C (CN) ₂ , —CH═CH—CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms. May be substituted with an alkyloxy group;
Y ₂ is a group selected from the group consisting of a divalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof, The hydrogen atoms bonded to each independently represent —NO ₂ , —CN, —CH═C (CN) ₂ , —CH═CH—CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or 1 to 5 carbon atoms. May be substituted with an alkyloxy group of
R represents a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, or the same definition as Y ₁ ;
X is a single bond, —COO—, —OCO—, —N═N—, —CH═CH—, —C≡C—, —CH═CH—CO—O—, or —O—CO—CH═. When CH is 2 and the number of X is 2, X may be the same or different;
Cou represents coumarin-6-yl group or a coumarin-7-yl group, _-NO 2 are each a hydrogen atom bonded to them _{independently, -CN, -CH = C (CN} ) 2, -CH = CH- May be substituted with CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms;
one of q1 and q2 is 1 and the other is 0;
q3 is 0 or 1;
P and Q are each independently selected from the group consisting of a divalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof. Provided that when X is —CH═CH—CO—O— or —O—CO—CH═CH—, P or Q on the side to which —CH═CH— is bonded is an aromatic ring; When the number of P is 2 or more, the Ps may be the same or different, and when the number of Q is 2 or more, the Qs may be the same or different;
l1 is 0 or 1;
l2 is an integer from 0 to 2;
when l1 and l2 are both 0, A represents a single bond when T is a single bond;
when l1 is 1, B represents a single bond when T is a single bond;
H and I are each independently a group selected from a divalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, and combinations thereof.

<7> In any one of the above items <1> to <6>, the component (A) has any one liquid crystalline side chain selected from the group consisting of the following formulas (21) to (31). Good.
In which A and B have the same definition as above;
Y ₃ is a group selected from the group consisting of a monovalent benzene ring, naphthalene ring, biphenyl ring, furan ring, nitrogen-containing heterocycle, alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof. And each hydrogen atom bonded thereto may be independently substituted with —NO ₂ , —CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms;
R ₃ is a hydrogen atom, —NO ₂ , —CN, —CH═C (CN) ₂ , —CH═CH—CN, halogen group, monovalent benzene ring, naphthalene ring, biphenyl ring, furan ring, nitrogen-containing A heterocyclic ring, 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;
one of q1 and q2 is 1 and the other is 0;
l represents an integer of 1 to 12, m represents an integer of 0 to 2, provided that in formulas (23) to (24), the sum of all m is 2 or more, and formulas (25) to (26 ), The sum of all m is 1 or more, and m1, m2 and m3 each independently represents an integer of 1 to 3;
R ₂ is a hydrogen atom, —NO ₂ , —CN, a halogen group, a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a nitrogen-containing heterocyclic ring, and an alicyclic hydrocarbon having 5 to 8 carbon atoms, And represents an alkyl group or an alkyloxy group;
Z ₁ and Z _{2 each} represents a single bond, —CO—, —CH ₂ O—, —CH═N—, or —CF ₂ —.

<8> A step of applying the polymer composition according to any one of <1> to <7> above onto a substrate having a conductive film for driving a lateral electric field to form a coating film;
[II] a step of irradiating the coating film obtained in [I] with polarized ultraviolet rays; and [III] a step of heating the coating film obtained in [II];
The manufacturing method of the board | substrate which has the said liquid crystal aligning film which obtains the liquid crystal aligning film for horizontal electric field drive type liquid crystal display elements by which orientation control ability was provided by having.
<9> A substrate having a liquid crystal alignment film for a lateral electric field drive type liquid crystal display device manufactured according to the above <8>.
<10> A lateral electric field drive type liquid crystal display device having the substrate of <9> above.
<11> A step of preparing the substrate (first substrate) of <9>above;
[I ′] A step of forming a coating film by applying the polymer composition according to any one of <1> to <7> above on a second substrate;
[II ′] a step of irradiating the coating film obtained in [I ′] with polarized ultraviolet rays; and [III ′] a step of heating the coating film obtained in [II ′];
Obtaining a liquid crystal alignment film imparted with alignment control ability by having a second substrate having the liquid crystal alignment film; and [IV] liquid crystal alignment films of the first and second substrates via liquid crystal The liquid crystal display element is obtained by disposing the first and second substrates so as to face each other;
A method for producing a liquid crystal display element, comprising obtaining a lateral electric field drive type liquid crystal display element.
<12> A lateral electric field drive type liquid crystal display device manufactured according to the above <11>.

According to the present invention, it is possible to provide a liquid crystal alignment film for a liquid crystal display element, which is imparted with a highly efficient alignment control ability and excellent in electrical characteristics, and a liquid crystal display element.
Further, in the present invention, by incorporating the heteropolyacid which is the component (B) into the polymer composition, a lateral electric field driving type liquid crystal element having an excellent voltage holding ratio even by low-temperature firing and liquid crystal alignment for the element A membrane can be provided.

As a result of intensive studies, the inventor has obtained the following knowledge and completed the present invention.
The polymer composition used in the production method of the present invention has a photosensitive side chain polymer that can exhibit liquid crystallinity (hereinafter, also simply referred to as a side chain polymer), and the polymer composition The coating film obtained by using the product is a film having a photosensitive side chain polymer that can exhibit liquid crystallinity. This coating film is subjected to orientation treatment by irradiation with polarized light without being rubbed. And after polarized light irradiation, it will become the coating film (henceforth a liquid crystal aligning film) to which the orientation control ability was provided through the process of heating the side chain type polymer film. At this time, the slight anisotropy developed by the irradiation of polarized light becomes a driving force, and the liquid crystalline side chain polymer itself is efficiently reoriented by self-organization. As a result, a highly efficient alignment process can be realized as the liquid crystal alignment film, and a liquid crystal alignment film with high alignment control ability can be obtained.

In the polymer composition of the present invention, a heteropolyacid is used as the component (B) in addition to the side chain polymer as the component (A) and the organic solvent as the component (C). It was unexpected that the voltage holding ratio was greatly improved. In addition to the fact that these phenomena are caused by the addition of the component (B), the present inventors exerted the interaction between the component (A) and the component (B), and jumped to the desired effect. (Note that these include the inventor's view on the mechanism of the present invention and do not bind the present invention).
Hereinafter, embodiments of the present invention will be described in detail.

<Polymer composition>
The polymer composition of the present invention comprises (A) a photosensitive side chain polymer that exhibits liquid crystallinity in a predetermined temperature range,
(B) contains a heteropolyacid, and (C) an organic solvent.

<< (A) Side chain polymer >>
The component (A) is a photosensitive side chain polymer that exhibits liquid crystallinity within a predetermined temperature range.
(A) The side chain polymer preferably reacts with light in the wavelength range of 250 nm to 400 nm and exhibits liquid crystallinity in the temperature range of 100 ° C to 300 ° C.
The (A) side chain polymer preferably has a photosensitive side chain that reacts with light in the wavelength range of 250 nm to 400 nm.
The (A) side chain polymer preferably has a mesogenic group in order to exhibit liquid crystallinity in the temperature range of 100 ° C to 300 ° C.

  (A) The side chain type polymer has a photosensitive side chain bonded to the main chain, and can react with light to cause a crosslinking reaction, an isomerization reaction, or a light fleece rearrangement. The structure of the side chain having photosensitivity is not particularly limited, but a structure that undergoes a crosslinking reaction or photofleece rearrangement in response to light is desirable, and a structure that causes a crosslinking reaction is more desirable. In this case, even if exposed to external stress such as heat, the achieved orientation control ability can be stably maintained for a long period of time. The structure of the photosensitive side chain polymer capable of exhibiting liquid crystallinity is not particularly limited as long as it satisfies such characteristics, but it is preferable to have a rigid mesogenic component in the side chain structure. In this case, stable liquid crystal alignment can be obtained when the side chain polymer is used as a liquid crystal alignment film.

  The polymer structure has, for example, a main chain and a side chain bonded to the main chain, and the side chain includes a mesogenic component such as a biphenyl group, a terphenyl group, a phenylcyclohexyl group, a phenylbenzoate group, and an azobenzene group, and a tip. A structure having a photosensitive group bonded to a moiety, which undergoes a crosslinking reaction or an isomerization reaction in response to light, or a main chain and a side chain bonded to the main chain, and the side chain also serves as a mesogenic component, and A structure having a phenylbenzoate group that undergoes a photo-Fries rearrangement reaction can be obtained.

  More specific examples of the structure of the photosensitive side chain polymer that can exhibit liquid crystallinity include hydrocarbon, (meth) acrylate, itaconate, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl , A main chain composed of at least one selected from the group consisting of radical polymerizable groups such as maleimide and norbornene and siloxane, and a side chain consisting of at least one of the following formulas (1) to (6) It is preferable that

In the formula, A, B, and D are each independently a single bond, —O—, —CH ₂ —, —COO—, —OCO—, —CONH—, —NH—CO—, —CH═CH—CO—. Represents O— or —O—CO—CH═CH—;
S is an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced by a halogen group;
T is a single bond or an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced with a halogen group;
Y ₁ represents a ring selected from a monovalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring and alicyclic hydrocarbon having 5 to 8 carbon atoms, or the same or selected from those substituents. 2 to 6 different rings are groups bonded through a bonding group B, and the hydrogen atoms bonded to them are each independently —COOR ₀ (wherein R ₀ is a hydrogen atom or a carbon number of 1 to 5 represents an alkyl group), —NO ₂ , —CN, —CH═C (CN) ₂ , —CH═CH—CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms. May be substituted with an alkyloxy group;
Y ₂ is a group selected from the group consisting of a divalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof, The hydrogen atoms bonded to each independently represent —NO ₂ , —CN, —CH═C (CN) ₂ , —CH═CH—CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or 1 to 5 carbon atoms. May be substituted with an alkyloxy group of
R represents a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, or the same definition as Y ₁ ;
X is a single bond, —COO—, —OCO—, —N═N—, —CH═CH—, —C≡C—, —CH═CH—CO—O—, or —O—CO—CH═. When CH is 2 and the number of X is 2, X may be the same or different;
Cou represents coumarin-6-yl group or a coumarin-7-yl group, _-NO 2 are each a hydrogen atom bonded to them _{independently, -CN, -CH = C (CN} ) 2, -CH = CH- May be substituted with CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms;
one of q1 and q2 is 1 and the other is 0;
q3 is 0 or 1;
P and Q are each independently selected from the group consisting of a divalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof. Provided that when X is —CH═CH—CO—O— or —O—CO—CH═CH—, P or Q on the side to which —CH═CH— is bonded is an aromatic ring; When the number of P is 2 or more, the Ps may be the same or different, and when the number of Q is 2 or more, the Qs may be the same or different;
l1 is 0 or 1;
l2 is an integer from 0 to 2;
when l1 and l2 are both 0, A represents a single bond when T is a single bond;
when l1 is 1, B represents a single bond when T is a single bond;
H and I are each independently a group selected from a divalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, and combinations thereof.

The side chain may be any one type of photosensitive side chain selected from the group consisting of the following formulas (7) to (10).
In which A, B, D, Y ₁ , X, Y ₂ and R have the same definition as above;
l represents an integer of 1 to 12;
m represents an integer of 0 to 2, and m1 and m2 represent an integer of 1 to 3;
n represents an integer of 0 to 12 (however, when n = 0, B is a single bond).

The side chain may be any one type of photosensitive side chain selected from the group consisting of the following formulas (11) to (13).
In the formula, A, X, l, m, m1 and R have the same definition as above.

The side chain may be a photosensitive side chain represented by the following formula (14) or (15).
In the formula, A, Y ₁ , l, m1 and m2 have the same definition as above.

The side chain may be a photosensitive side chain represented by the following formula (16) or (17).
In the formula, A, X, l and m have the same definition as above.

The side chain is preferably a photosensitive side chain represented by the following formula (18) or (19).
In the formula, A, B, Y1, q1, q2, m1, and m2 have the same definition as above.
R ₁ is a hydrogen atom, —NO ₂ , —CN, —CH═C (CN) ₂ , —CH═CH—CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms. Represents an oxy group.

The side chain is preferably a photosensitive side chain represented by the following formula (20).
In the formula, A, Y ₁ , X, l and m have the same definition as above.

The (A) side chain polymer preferably has any one liquid crystalline side chain selected from the group consisting of the following formulas (21) to (31).
In which A, B, q1 and q2 have the same definition as above;
Y ₃ is a group selected from the group consisting of a monovalent benzene ring, naphthalene ring, biphenyl ring, furan ring, nitrogen-containing heterocycle, alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof. And each hydrogen atom bonded thereto may be independently substituted with —NO ₂ , —CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms;
R ₃ is a hydrogen atom, —NO ₂ , —CN, —CH═C (CN) ₂ , —CH═CH—CN, halogen group, monovalent benzene ring, naphthalene ring, biphenyl ring, furan ring, nitrogen-containing A heterocyclic ring, 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, provided that in formulas (23) to (24), the sum of all m is 2 or more, and formulas (25) to (26 ), The sum of all m is 1 or more, and m1, m2 and m3 each independently represents an integer of 1 to 3;
R ₂ is a hydrogen atom, —NO ₂ , —CN, a halogen group, a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a nitrogen-containing heterocyclic ring, and an alicyclic hydrocarbon having 5 to 8 carbon atoms, And represents an alkyl group or an alkyloxy group;
Z ₁ and Z _{2 each} represents a single bond, —CO—, —CH ₂ O—, —CH═N—, or —CF ₂ —.

[Photoreactive side chain monomer]
The photoreactive side chain monomer is a monomer capable of forming a polymer having a photosensitive side chain at the side chain portion of the polymer when the polymer is formed.
As the photoreactive group possessed by the side chain, the following structures and derivatives thereof are preferred.

  More specific examples of the photoreactive side chain monomer include radical polymerizable groups such as hydrocarbon, (meth) acrylate, itaconate, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide and norbornene. And a polymerizable side group composed of at least one selected from the group consisting of siloxane and a photosensitive side chain consisting of at least one of the above formulas (1) to (6), preferably, for example, the above formula (7 ) To (10), a photosensitive side chain comprising at least one of the above formulas (11) to (13), and a photosensitivity represented by the above formula (14) or (15). A photosensitive side chain, a photosensitive side chain represented by the above formula (16) or (17), a photosensitive side chain represented by the above formula (18) or (19), and a photosensitivity represented by the above formula (20). Has sex side chain It is preferable that the structure be

[Liquid crystal side chain monomer]
The liquid crystalline side chain monomer is a monomer in which a polymer derived from the monomer exhibits liquid crystallinity and the polymer can form a mesogenic group at a side chain site.
As a mesogenic group having a side chain, even if it is a group having a mesogen structure alone such as biphenyl or phenylbenzoate, or a group having a mesogen structure by hydrogen bonding between side chains such as benzoic acid Good. As the mesogenic group possessed by the side chain, the following structure is preferable.

  More specific examples of the liquid crystalline side chain monomer include hydrocarbon, (meth) acrylate, itaconate, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, norbornene and other radical polymerizable groups. A structure having a polymerizable group composed of at least one selected from the group consisting of siloxanes and a side chain composed of at least one of the above formulas (21) to (31) is preferable.

The content of the photoreactive side chain in the side chain polymer as the component (A) of the present invention is preferably 10 mol% to 100 mol%, and preferably 15 mol% to 95 mol% from the viewpoint of liquid crystal alignment. More preferably, 20 mol%-80 mol% are still more preferable.

The content of the liquid crystalline side chain in the side chain polymer as the component (A) of the present invention is preferably 0 to 90 mol%, more preferably 5 mol% to 85 mol% from the viewpoint of liquid crystal alignment. 20 mol% to 80 mol% or less is more preferable.
<Specific copolymer unit>
The polymer which is the component (A) in the present invention can contain a specific copolymer for the purpose of further improving the properties. Examples of the specific copolymer unit include a side chain represented by the following formula (0) and the following side chain (b-2).

[Side Chain Represented by Formula (0)]
The side chain represented by Formula (0) is as follows.

In the formula, A and B are each independently a single bond, —O—, —CH ₂ —, —COO—, —OCO—, —CONH—, —NH—CO—, —CH═CH—CO—O—. Or -O-CO-CH = CH-;
S is an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced by a halogen group;
T is a single bond or an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced with a halogen group;
X is a single bond, —COO—, —OCO—, —N═N—, —CH═CH—, —C≡C—, —CH═CH—CO—O—, or —O—CO—CH═. When CH is 2 and the number of X is 2, X may be the same or different;
P and Q are each independently selected from the group consisting of a divalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof. Provided that when X is —CH═CH—CO—O— or —O—CO—CH═CH—, P or Q on the side to which —CH═CH— is bonded is an aromatic ring;
l1 is 0 or 1;
l2 is an integer from 0 to 2;
when l1 and l2 are both 0, A represents a single bond when T is a single bond;
when l1 is 1, B represents a single bond when T is a single bond;
G represents the following formulas (G-1), (G-2), (G-3) and (G-4).

(In the formula, a broken line represents a bond, R ⁵⁰ represents a group selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a phenyl group, and when there are a plurality of R ^50, they are the same or different from each other. T is an integer of 1 to 7, J represents O, S, NH or NR ⁵¹ , and R ⁵¹ represents a group selected from an alkyl group having 1 to 3 carbon atoms and a phenyl group). Group.

More specific examples of the monomer having a side chain represented by the formula (0) include hydrocarbon, (meth) acrylate, itaconate, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide. It is preferably a structure having a polymerizable group composed of at least one selected from the group consisting of radical polymerizable groups such as norbornene and siloxane, and a side chain represented by the above formula (0).

Among such monomers, specific examples of the monomer having an epoxy group include compounds such as glycidyl (meth) acrylate, (3,4-epoxycyclohexyl) methyl (meth) acrylate, and allyl glycidyl ether. Among them, glycidyl (meth) acrylate, (3,4-epoxycyclohexyl) methyl (meth) acrylate, 3-ethenyl-7-oxabicyclo [4.1.0] heptane, 1,2-epoxy-5 Examples include hexene and 1,7-octadiene monoepoxide.

Specific examples of the monomer having thiirane include those obtained by replacing the epoxy structure of the monomer having an epoxy group with thiirane.
Specific examples of the monomer having an aziridine include those in which the epoxy structure of the monomer having an epoxy group is replaced with aziridine or 1-methylaziridine.

Examples of the monomer having an oxetane group include (meth) acrylic acid ester having an oxetane group. Among such monomers, 3- (methacryloyloxymethyl) oxetane, 3- (acryloyloxymethyl) oxetane, 3- (methacryloyloxymethyl) -3-ethyl-oxetane, 3- (acryloyloxymethyl) -3- Ethyl-oxetane, 3- (methacryloyloxymethyl) -2-trifluoromethyloxetane, 3- (acryloyloxymethyl) -2-trifluoromethyloxetane, 3- (methacryloyloxymethyl) -2-phenyl-oxetane, 3- (Acryloyloxymethyl) -2-phenyl-oxetane, 2- (methacryloyloxymethyl) oxetane, 2- (acryloyloxymethyl) oxetane, 2- (methacryloyloxymethyl) -4-trifluoromethyloxetane, 2- (acryloyl) Oxymethyl) -4-trifluoromethyl oxetane are preferable, 3- (methacryloyloxy) -3-ethyl - oxetane, 3- (acryloyloxy-methyl) -3-ethyl - oxetane, and the like.

As the monomer having a thietane group, for example, a monomer in which the oxetane group of the monomer having an oxetane group is replaced with a thietane group is preferable.

As the monomer having an azetan group, for example, a monomer in which an oxetane group of a monomer having an oxetane group is replaced with an azetan group is preferable.

Among the above, a monomer having an epoxy group and a monomer having an oxetane group are preferable from the viewpoint of availability and the like, and a monomer having an epoxy group is more preferable. Among these, glycidyl (meth) acrylate is preferable from the viewpoint of availability.

[Side Chain (b-2)]
The side chain (b-2) is a side chain having a group selected from a pyridyl group, an amide group and a urethane group. By containing such a side chain (b-2), when the liquid crystal alignment film is formed, the elution of ionic impurities is reduced and the crosslinking reaction of the group represented by the formula (0) is promoted. Or a more durable liquid crystal aligning film can be obtained. In order to produce a polymer having a side chain (b-2), a monomer having a side chain (b-2) may be copolymerized.

Examples of the monomer having such a side chain (b-2) include hydrocarbon, (meth) acrylate, itaconate, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, norbornene, and other radical polymerizable groups. A structure having a polymerizable group composed of at least one selected from the group consisting of siloxane and a side chain having a pyridyl group, an amide group and a urethane group is preferable. NH in the amide group and urethane group may or may not be substituted. Examples of the substituent in the case where it may be substituted include an alkyl group, an amino-protecting group, and a benzyl group.

Among such monomers, specific examples of monomers having a pyridyl group include 2- (2-pyridylcarbonyloxy) ethyl (meth) acrylate and 2- (3-pyridylcarbonyloxy) ethyl (meth) acrylate. , 2- (4-pyridylcarbonyloxy) ethyl (meth) acrylate, and the like.

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 include N- (tertiary butyloxycarbonyl) piperidin-4-yl ester, 4- (6-methacryloyloxyhexyloxy) benzoic acid 2- (tertiary butyloxycarbonylamino) ethyl ester, and the like.

<< Polymer manufacturing process >>
The photosensitive side chain polymer capable of exhibiting liquid crystallinity of the component (A) is obtained by polymerizing the photoreactive side chain monomer having the above photosensitive side chain and the liquid crystalline side chain monomer. Can do.

  (A) The side chain polymer can be obtained by the polymerization reaction of the above-described photoreactive side chain monomer exhibiting liquid crystallinity. Further, it can be obtained by copolymerization of a photoreactive side chain monomer that does not exhibit liquid crystallinity and a liquid crystalline side chain monomer, or by copolymerization of a photoreactive side chain monomer that exhibits liquid crystallinity and a liquid crystalline side chain monomer. it can. Furthermore, it can also be copolymerized with the monomer which gives the side chain (0) or the monomer which gives the side chain (b-2).

Moreover, (A) component can be copolymerized with another monomer in the range which does not impair a characteristic.
Examples of other monomers include industrially available monomers capable of radical polymerization reaction.
Specific examples of the other monomer include unsaturated carboxylic acid, acrylic ester compound, methacrylic ester compound, maleimide compound, acrylonitrile, maleic anhydride, styrene compound and vinyl compound.

Specific examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid and the like.
Examples of the acrylate 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- Propyl-2-adamantyl acrylate, 8-methyl-8-tricyclodecyl acrylate, and , Etc. 8-ethyl-8-tricyclodecyl acrylate.

  Examples of the methacrylic acid 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, tert-butyl. Methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2-ethoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 3-methoxybutyl methacrylate, 2-methyl-2-adamantyl methacrylate, 2- Propyl-2-adamantyl methacrylate, 8-methyl 8 tricyclodecyl methacrylate, and, 8-ethyl-8-tricyclodecyl methacrylate. (Meth) acrylate compounds having a cyclic ether group such as glycidyl (meth) acrylate, (3-methyl-3-oxetanyl) methyl (meth) acrylate, and (3-ethyl-3-oxetanyl) methyl (meth) acrylate are also used. be able to.

Examples of the vinyl compound include vinyl ether, methyl vinyl ether, benzyl vinyl ether, 2-hydroxyethyl vinyl ether, phenyl vinyl ether, and propyl vinyl ether.
Examples of the styrene compound include styrene, methylstyrene, chlorostyrene, bromostyrene, and the like.
Examples of maleimide compounds include maleimide, N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide.

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

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

  The radical thermal polymerization initiator is a compound that generates radicals by heating to a decomposition temperature or higher. Examples of such radical thermal polymerization initiators include ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), diacyl peroxides (acetyl peroxide, benzoyl peroxide, etc.), hydroperoxides (peroxidation). Hydrogen, tert-butyl hydride peroxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyketals (dibutyl peroxy cyclohexane) Etc.), alkyl peresters (peroxyneodecanoic acid-tert-butyl ester, peroxypivalic acid-tert-butyl ester, peroxy 2-ethylcyclohexane Sanic acid-tert-amyl ester, etc.), persulfates (potassium persulfate, sodium persulfate, ammonium persulfate, etc.), azo compounds (azobisisobutyronitrile, and 2,2'-di (2-hydroxyethyl) And azobisisobutyronitrile). Such radical thermal polymerization initiators can be used singly or in combination of two or more.

  The radical photopolymerization initiator is not particularly limited as long as it is a compound that initiates radical polymerization by 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, 2-hydroxy 2-methylpropiophenone, 2-hydroxy-2-methyl-4′-isopropylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, isopropyl benzoin ether, isobutyl benzoin ether, 2,2-diethoxyacetophenone, 2,2 -Dimethoxy-2-phenylacetophenone, camphorquinone, benzanthrone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2- N-di-2-dimethylamino-1- (4-morpholinophenyl) -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-diethylamino) Coumarin), 2- (o-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole, 2,2′-bi (2-chlorophenyl) -4,4 ′, 5,5′-tetrakis (4-ethoxycarbonylphenyl) -1,2′-biimidazole, 2,2′-bis (2,4-dichlorophenyl) -4, 4 ′, 5,5′-tetraphenyl-1,2′-biimidazole, 2,2′bis (2,4-dibromophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2 ′ -Biimidazole, 2,2'-bis (2,4,6-trichlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-biimidazole, 3- (2-methyl-2 -Dimethylaminopropionyl) carbazole, 3,6-bis (2-methyl-2-morpholinopropionyl) -9-n-dodecylcarbazole, 1-hydroxycyclohexyl phenyl ketone, bis (5-2,4-cyclopentadi) N-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-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 (methoxycarbonyl) -4,3'-di (t-butylperoxycarbonyl) benzophenone, 4,4'-di (methoxycarbonyl) -3,3'-di (t-butylperoxycarbonyl) benzophenone, 2, -(3-methyl-3H-benzothiazol-2-ylidene) -1-naphthalen-2-yl-ethanone or 2- (3-methyl-1 3- benzothiazol -2 (3H) - ylidene) -1- (2-benzoyl) ethanone, and the like. These compounds may be used alone or in combination of two or more.

  The radical polymerization method is not particularly limited, and an emulsion polymerization method, suspension polymerization method, dispersion polymerization method, precipitation polymerization method, bulk polymerization method, 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 generated polymer is soluble. Specific examples are given below.

  N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetramethyl urea, pyridine, dimethyl sulfone, hexamethyl sulfoxide , Γ-butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl Carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethyl 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 butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, dioxane, n- Hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, Ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropion , 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N, N-dimethylpropanamide, 3-ethoxy -N, N-dimethylpropanamide, 3-butoxy-N, N-dimethylpropanamide and the like can be mentioned.

These organic solvents may be used alone or in combination. Furthermore, even if it is a solvent which does not dissolve the polymer | macromolecule to produce | generate, you may mix and use the above-mentioned organic solvent in the range which the polymer | macromolecule produced | generated does not precipitate.
In radical polymerization, oxygen in the organic solvent becomes a cause of inhibiting the polymerization reaction. Therefore, it is preferable to use an organic solvent that has been deaerated to the extent possible.

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

  In the above-mentioned radical polymerization reaction, the molecular weight of the obtained polymer is decreased when the ratio of the radical polymerization initiator is large relative to the monomer, and the molecular weight of the obtained polymer is increased when the ratio is small, the ratio of the radical initiator is It is preferable that it is 0.1 mol%-10 mol% with respect to the monomer to superpose | polymerize. Further, various monomer components, solvents, initiators and the like can be added during the polymerization.

[Recovery of polymer]
When recovering the produced polymer from the reaction solution of the photosensitive side chain polymer capable of exhibiting liquid crystallinity obtained by the above reaction, the reaction solution is put into a poor solvent, The coalescence can be precipitated. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, and water. The polymer deposited in a poor solvent and precipitated can be recovered by filtration and then dried at normal temperature or under reduced pressure at room temperature or by heating. Moreover, when the polymer which carried out precipitation collection | recovery is re-dissolved in an organic solvent and the operation which carries out reprecipitation collection | recovery is repeated 2 to 10 times, the impurity in a polymer can be decreased. 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 purification efficiency is further improved.

  The molecular weight of the (A) side chain polymer of the present invention is measured by the GPC (Gel Permeation Chromatography) method in consideration of the strength of the obtained coating film, workability during coating film formation, and coating film uniformity. The weight average molecular weight is preferably from 2,000 to 1,000,000, more preferably from 5,000 to 100,000.

The content in the case where the side chain polymer as the component (A) of the present invention further contains a side chain represented by the formula (0) is from the viewpoint of improving reliability and affecting liquid crystal orientation. 20 mol% or less, preferably 10 mol% or less, more preferably 5 mol% or less.

In the case where the side chain type polymer as the component (A) of the present invention further contains a side chain (b-2), the content is 80 mol from the viewpoint of improvement in reliability and influence on liquid crystal orientation. % Or less is preferable, 60 mol% or less is more preferable, and 40 mol% or less is still more preferable.

The side chain type polymer as the component (A) of the present invention includes a photoreactive side chain, a side chain represented by the above formula (b), a liquid crystalline side chain, and a side chain represented by the above formula (0). Other side chains other than the side chain (b-2) may be contained. The total content of the photoreactive side chain, liquid crystalline side chain, side chain represented by the above formula (0), and side chain (b-2) of the component (A) is 100%. If not, the rest.

In addition, the ratio of these side chains can be controlled by adjusting the molar fraction of the monomer which gives each side chain, when manufacturing a side chain type polymer.

<< (B) component >>
The specific compound in the present invention is a heteropolyacid. The heteropolyacid in the present invention is a concept including a free acid and neutral and acidic salts thereof. Here, the acid salt means a salt of a heteropolyacid (HPA) in which some of hydrogen ions are replaced with a basic cation, for example, an alkali metal cation. Accordingly, the heteropolyacid used in the catalyst of the present invention includes a free acid and a coordination salt thereof, and an anion exists as a complex high molecular weight substance in the salt. Typically, the anion contains a polyvalent metal atom bonded with 2-18 oxygens, which is called a peripheral atom. These peripheral atoms symmetrically surround one or more central atoms. The peripheral atoms are usually at least one selected from the group consisting of one or more molybdenum, tungsten, vanadium, niobium, tantalum, and other metals. The central atom is usually silicon or phosphorus, but may contain elements belonging to Groups IA-VIIA and VIII of the periodic table of elements. Examples of ions of these elements include cupric ions; divalent beryllium, zinc, cobalt, or nickel ions; trivalent boron, aluminum, gallium, iron, cerium, arsenic, antimony, phosphorus, bismuth, and chromium. Or rhodium ions; tetravalent silicon, germanium, tin, titanium, zirconium, vanadium, sulfur, tellurium, manganese, nickel, platinum, thorium, hafnium, cerium ions, and other rare earth ions; pentavalent Examples include phosphorus, arsenic, vanadium, and antimony ions; hexavalent tellurium ions; and heptavalent iodine ions. Heteropolyacids are also known as “polyoxoanions”, “polyoxometalates” or “metal oxide clusters”. Typical anion structures include Keggin structure, Wells-Dawson structure, Anderson-Evans-Perloff structure (all named after pioneering researchers in the field) ).

Typically, it has a structure in which a heteroatom is located at the center of the molecule, which is represented by a Keggin type represented by the following formula [1-1] or a Dawson type chemical structure represented by the formula [1-2]. , A polyacid obtained by condensing an isopolyacid that is an oxygen acid such as vanadium (V), molybdenum (Mo), or tungsten (W) and an oxygen acid of a different element. Examples of the oxygen acid of such a different element mainly include silicon (Si), phosphorus (P), and arsenic (As) oxygen acids.

The heteropolyacid usually has a high molecular weight of, for example, about 700 to 8500 and may take the structure of a dimeric complex. Heteropolyacids have a relatively high solubility in polar solvents such as water and other oxygen-containing solvents. This solubility is known to increase when the heteropolyacid takes the form of a free acid or certain salts, and can be adjusted by selecting an appropriate counterion.

  Specific examples of the heteropolyacid compound include phosphotungstic acid, phosphomolybdic acid, silicotungstic acid, silicomolybdic acid, phosphotungstomolybdic acid or a salt thereof, and the like are preferably used in the present invention. Moreover, these may be used independently and may be used in combination of 2 or more types.

More specifically, the following can be exemplified: phosphorus-12-tungstic acid (H ₃ [PW ₁₂ O ₄₀ ] xH ₂ O), phosphorus-12-molybdic acid (H ₃ [PMo ₁₂ O ₄₀ ] xH ₂₎ O), silicic 12- tungstate _{(H 4 [SiW 12 O 40} ] xH 2 O), silica-12-tungstic acid monosodium _{(H 3 Na [SiW 12 O} 40] xH 2 O), silica-12- Molybdic acid (H ₄ [SiMo ₁₂ O ₄₀ ] xH ₂ O), potassium phosphotungstate (K ₆ [P ₂ W ₁₈ O ₆₂ ] xH ₂ O), sodium phosphomolybdate (Na ₃ [PMo ₁₂ O ₄₀ ] xH ₂ O), diphosphorus-ammonium molybdate ((NH ₄ ) ₆ [P ₂ Mo ₁₈ O ₆₂ ] xH ₂ O), nickel-sodium tungstate (Na ₄ [NiW ₆ O ₂₄ H ₆ ] xH ₂ O), Dicobalt-molybdate Bromide _{((NH 4) [Co 2} Mo 10 O 36] xH 2 O), silicotungstic acid cesium hydrogen _{(Cs 3 H [SiW 12 O} 40] xH 2 O), potassium phosphate molybdate blunder vanadate (K ₅ [PMoV _{2 O 40] xH 2 O)} .

In addition, the heteropolyacid compound in this invention is available as a commercial item, and can also be synthesize | combined by a well-known method.
Heteropoly acids can be obtained as commercial products in the quantitative analysis such as elemental analysis, even if the number of elements is large or small from the structure represented by the general formula, or appropriately synthesized according to known synthesis methods. As long as it is, it can be used in the present invention.

The content of the heteropolyacid as the component (B) in the composition is 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the component (A).

<< (C) Organic solvent >>
The organic solvent used for 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-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, 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-imidazolidinone, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethylene carbonate, propylene carbonate, diglyme, 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 ether, etc. Is mentioned. These may be used alone or in combination.

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

The following are mentioned as a specific example of the solvent (poor solvent) which improves the uniformity of film thickness and surface smoothness.
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 monoacetate 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, dipro Lenglycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3 -Methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl Ether, 1-hexanol, n-hexane, n-pentane, n-octane Diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, Ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1 -Butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol- Low 1-monoethyl ether-2-acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, lactate isoamyl ester Examples include solvents having surface tension.

  These poor solvents may be used alone or in combination. When using the solvent as described above, it is preferably 5% by mass to 80% by mass of the total solvent, more preferably so as not to significantly reduce the solubility of the entire solvent contained in the polymer composition. Is 20% by mass to 60% by mass.

Examples of the compound that improves film thickness uniformity and surface smoothness include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants.
More specifically, for example, Ftop (registered trademark) 301, EF303, EF352 (manufactured by Tochem Products), MegaFac (registered trademark) F171, F173, R-30 (manufactured by DIC), Florard FC430, FC431 (Manufactured by Sumitomo 3M), Asahi Guard (registered trademark) AG710 (manufactured by Asahi Glass Company), Surflon (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by AGC Seimi Chemical Co., Ltd.) It is done. The use ratio of these surfactants is preferably 0.01 parts by mass to 2 parts by mass, more preferably 0.01 parts by mass to 1 part with respect to 100 parts by mass of the resin component contained in the polymer composition. Part by mass.

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-to Ethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltri Methoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-amino Examples thereof include propyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane.

  Furthermore, in addition to improving the adhesion between the substrate and the liquid crystal alignment film, the addition of the following phenoplasts and epoxy group-containing compounds for the purpose of preventing the deterioration of electrical characteristics due to the backlight when the liquid crystal display element is constructed An agent may be contained in the polymer composition. Specific phenoplast 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-dibromoneopentylglycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N ′,-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N ′,-tetraglycidyl-4 4'-diaminodiphenylmethane and the like.

  When using the compound which improves adhesiveness with a board | substrate, it is preferable that the usage-amount is 0.1 mass part-30 mass parts with respect to 100 mass parts of the resin component contained in a polymer composition. More preferably, it is 1 mass part-20 mass parts. If the amount used is less than 0.1 parts by mass, the effect of improving the adhesion cannot be expected, and if it exceeds 30 parts by mass, the orientation of the liquid crystal may deteriorate.

A photosensitizer can also be used as an additive. Colorless and triplet sensitizers are preferred.
As photosensitizers, aromatic nitro compounds, coumarins (7-diethylamino-4-methylcoumarin, 7-hydroxy-4-methylcoumarin), ketocoumarins, carbonyl biscoumarins, aromatic 2-hydroxyketones, and amino substituted Aromatic 2-hydroxyketone (2-hydroxybenzophenone, mono- or di-p- (dimethylamino) -2-hydroxybenzophenone), acetophenone, anthraquinone, xanthone, thioxanthone, benzanthrone, thiazoline (2-benzoylmethylene-3 -Methyl-β-naphthothiazoline, 2- (β-naphthoylmethylene) -3-methylbenzothiazoline, 2- (α-naphthoylmethylene) -3-methylbenzothiazoline, 2- (4-biphenoylmethylene)- 3-methylbenzothia Phosphorus, 2- (β-naphthoylmethylene) -3-methyl-β-naphthothiazoline, 2- (4-biphenoylmethylene) -3-methyl-β-naphthothiazoline, 2- (p-fluorobenzoylmethylene)- 3-methyl-β-naphthothiazoline), oxazoline (2-benzoylmethylene-3-methyl-β-naphthoxazoline, 2- (β-naphthoylmethylene) -3-methylbenzoxazoline, 2- (α-naphthoylmethylene) ) -3-methylbenzoxazoline, 2- (4-biphenoylmethylene) -3-methylbenzoxazoline, 2- (β-naphthoylmethylene) -3-methyl-β-naphthoxazoline, 2- (4-biphenoyl) Methylene) -3-methyl-β-naphthoxazoline, 2- (p-fluorobenzoylmethylene) -3-methyl-β- Ftoxazoline), benzothiazole, nitroaniline (m- or p-nitroaniline, 2,4,6-trinitroaniline) or nitroacenaphthene (5-nitroacenaphthene), (2-[(m-hydroxy-p -Methoxy) styryl] benzothiazole, benzoin alkyl ether, N-alkylated phthalone, acetophenone ketal (2,2-dimethoxyphenylethanone), naphthalene, anthracene (2-naphthalenemethanol, 2-naphthalenecarboxylic acid, 9-anthracenemethanol And 9-anthracenecarboxylic acid), benzopyran, azoindolizine, melocoumarin and the like.
Aromatic 2-hydroxyketone (benzophenone), coumarin, ketocoumarin, carbonyl biscoumarin, acetophenone, anthraquinone, xanthone, thioxanthone, and acetophenone ketal are preferred.

[Preparation of polymer composition]
The polymer composition of the present invention contains a photosensitive side chain polymer as component (A), a heteropolyacid as component (B), and an organic solvent as component (C). In addition to the (A) component, the (B) component, and the (C) component, the polymer composition of the present invention further improves film thickness uniformity and surface smoothness when the polymer composition is applied. It can also contain a solvent, a compound, a compound for improving the adhesion between the liquid crystal alignment film and the substrate, and the like. And as long as the effect of this invention is not impaired, another additive can be contained.

  The method for preparing the polymer composition of the present invention is not particularly limited. As a preparation method, for example, (C) a solution of component (A) dissolved in a solvent and (B) component are mixed at a predetermined ratio to make a uniform solution, or at an appropriate stage of this preparation method In addition, there may be mentioned a method of further adding and mixing other additives as required.

  In the preparation of the polymer composition of the present invention, a solution of a specific copolymer obtained by a polymerization reaction in a solvent can be used as it is. In this case, for example, the component (B) is added to the solution of the component (A) to obtain a uniform solution. At this time, a solvent may be further added for the purpose of adjusting the concentration. At this time, the solvent used in the production process of the component (A) and the solvent used for adjusting the concentration of the polymer composition may be the same or different.

The prepared polymer composition solution is preferably used after being filtered using a filter having a pore size of about 0.2 μm.
The polymer composition used in the present invention is preferably prepared as a coating solution 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 polymer capable of exhibiting the liquid crystallinity already described. In that case, the content of the resin component is preferably 1% by mass to 20% by mass, more preferably 3% by mass to 15% by mass, and particularly preferably 3% by mass to 10% by mass.

In the polymer composition of the present embodiment, the resin component described above may be only a photosensitive side chain polymer capable of exhibiting liquid crystallinity as the component (A) described above. Other polymers may be mixed as long as the photosensitive performance is not impaired. In that case, content of the other polymer in a resin component is 0.5 mass%-80 mass%, Preferably it is 1 mass%-50 mass%.
Such other polymers include, for example, polymers that are made of poly (meth) acrylate, polyamic acid, polyimide, and the like and are not the component (A) described above.

<Manufacturing method of substrate having liquid crystal alignment film> and <Manufacturing method of liquid crystal display element>
A manufacturing method of a substrate having a liquid crystal alignment film and a manufacturing method of a liquid crystal display element are:
[I] A step of applying the polymer composition of the present invention on a substrate having a conductive film for driving a transverse electric field to form a coating film;
[II] a step of irradiating the coating film obtained in [I] with polarized ultraviolet rays; and [III] a step of heating the coating film obtained in [II];
Have
Through the above steps, a liquid crystal alignment film for a lateral electric field drive type liquid crystal display element to which alignment control ability is imparted can be obtained, and a substrate having the liquid crystal alignment film can be obtained.

Further, by preparing a second substrate in addition to the obtained substrate (first substrate), a lateral electric field drive type liquid crystal display element can be obtained.
The second substrate is replaced with a substrate having no lateral electric field driving conductive film instead of a substrate having no lateral electric field driving conductive film, except that the above steps [I] to [III] (lateral electric field driving For the sake of convenience, the substrate having no conductive film is sometimes referred to as processes [I ′] to [III ′] in some cases for the sake of convenience. Two substrates can be obtained.

The manufacturing method of the horizontal electric field drive type 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 that the liquid crystal alignment films of the first and second substrates face each other with liquid crystal interposed therebetween;
Have Thereby, a horizontal electric field drive type liquid crystal display element can be obtained.

Hereinafter, each process of [I]-[III] and [IV] which the manufacturing method of this invention has is demonstrated.
<Process [I]>
In step [I], a photosensitive side chain polymer that exhibits liquid crystallinity in a predetermined temperature range as component (A) on a substrate having a conductive film for driving a lateral electric field, component (B). A polymer composition containing a heteropolyacid and an organic solvent as component (C) is applied to form a coating film.

<Board>
Although it does not specifically limit about a board | substrate, When the liquid crystal display element manufactured is a transmission type, it is preferable that a highly transparent board | substrate is used. In that case, there is no particular limitation, and a glass substrate or a plastic substrate such as an acrylic substrate or a polycarbonate substrate can be used.
In consideration of application to a reflective liquid crystal display element, an opaque substrate such as a silicon wafer can also be used.

<Conductive film for driving lateral electric field>
The substrate has a conductive film for driving a lateral electric field.
Examples of the conductive film include, but are not limited to, ITO (Indium Tin Oxide) and IZO (Indium Zinc Oxide) when the liquid crystal display element is a transmission type.
In the case of a reflective liquid crystal display element, examples of the conductive film include a material that reflects light such as aluminum, but are not limited thereto.
As a method for forming a conductive film on a substrate, a conventionally known method can be used.

  In the polymer composition, in addition to the above-described ones, a dielectric, a conductive substance, or the like 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. Furthermore, a crosslinkable compound may be added for the purpose of increasing the hardness and density of the liquid crystal alignment film.

The method for applying the polymer composition described above onto a substrate having a conductive film for driving a lateral electric field is not particularly limited.
In general, the application method is generally performed by screen printing, offset printing, flexographic printing, an inkjet method, or the like. Other coating methods include a dipping method, a roll coater method, a slit coater method, a spinner method (rotary coating method), or a spray method, and these may be used depending on the purpose.

After the polymer composition is applied onto the substrate having the conductive film for driving the transverse electric field, it is 50 to 200 ° C., preferably 50 to 200 ° C. by a heating means such as a hot plate, a thermal circulation oven or an IR (infrared) oven. The solvent can be evaporated at 150 ° C. to obtain a coating film. 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 be lowered. Therefore, it is preferably 5 nm to 300 nm, more preferably 10 nm to 150 nm. It is.
In addition, it is also possible to provide the process of cooling the board | substrate with which the coating film was formed to room temperature after the [I] process and before the following [II] process.

<Process [II]>
In step [II], the coating film obtained in step [I] is irradiated with polarized ultraviolet rays. When irradiating the surface of the coating film with polarized ultraviolet rays, the substrate is irradiated with polarized ultraviolet rays through a polarizing plate from a certain direction. As the ultraviolet rays to be used, ultraviolet rays having a wavelength in the range of 100 nm 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 to be used. For example, ultraviolet rays having a wavelength in the range of 290 nm to 400 nm can be selected and used so that the photocrosslinking reaction can be selectively induced. As the ultraviolet light, for example, light emitted from a high-pressure mercury lamp can be used.

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

<Step [III]>
In step [III], the ultraviolet-irradiated coating film polarized in step [II] is heated. An 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 crystallinity of the coating film used is developed.

The heating temperature is preferably within a temperature range of a temperature at which the side chain polymer exhibits liquid crystallinity (hereinafter referred to as liquid crystallinity expression temperature). In the case of a thin film surface such as a coating film, the liquid crystallinity expression temperature of the coating film surface may be lower than the liquid crystallinity expression temperature when a photosensitive side chain polymer capable of expressing liquid crystallinity is observed in bulk. is expected. For this reason, the heating temperature is more preferably within the temperature range of the liquid crystallinity expression temperature on the coating film surface. That is, the temperature range of the heating temperature after irradiation with polarized ultraviolet rays is 10 ° C. lower than the upper limit of the liquid crystal temperature range, with the temperature being 10 ° C. lower than the lower limit of the temperature range of the liquid crystalline expression temperature of the side chain polymer used. It is preferable that the temperature is in a range where the temperature is the upper limit. If the heating temperature is lower than the above temperature range, the anisotropic amplification effect due to heat in the coating film tends to be insufficient, and if the heating temperature is too higher than the above temperature range, the state of the coating film Tends to be close to an isotropic liquid state (isotropic phase), and in this case, self-organization may make it difficult to reorient in one direction.
The liquid crystallinity temperature is equal to or higher than the glass transition temperature (Tg) at which the side chain polymer or coating film surface undergoes a phase transition from the solid phase to the liquid crystal phase, and from the liquid crystal phase to the isotropic phase (isotropic phase). Refers to a temperature below the isotropic phase transition temperature (Tiso) that causes a phase transition.

  By having the above steps, the production method of the present invention can realize highly efficient introduction of anisotropy into the coating film. And a board | substrate with a liquid crystal aligning film can be manufactured highly efficiently.

<Process [IV]>
The step [IV] is performed in the same manner as the above [I ′] to [III ′] in the same manner as the substrate (first substrate) obtained in [III] and having a liquid crystal alignment film on the conductive film for driving a horizontal electric field. The obtained liquid crystal alignment film-attached substrate (second substrate) having no conductive film is placed oppositely so that both liquid crystal alignment films face each other through liquid crystal, and a liquid crystal cell is formed by a known method. This is a step of manufacturing a lateral electric field drive type liquid crystal display element. The steps [I ′] to [III ′] are the same as the steps [I] except that a substrate having no lateral electric field driving conductive film is used instead of the substrate having the lateral electric field driving conductive film. It can carry out similarly to process [I]-[III]. Since the difference between the steps [I] to [III] and the steps [I ′] to [III ′] is only the presence or absence of the conductive film, the description of the steps [I ′] to [III ′] is omitted. To do.

  To give an example of the production of a liquid crystal cell or a liquid crystal display element, the first and second substrates described above are prepared, spacers are dispersed on the liquid crystal alignment film of one substrate, and the liquid crystal alignment film surface is on the inside. In this way, the other substrate is bonded and the liquid crystal is injected under reduced pressure, or the liquid crystal is dropped on the liquid crystal alignment film surface on which the spacers are dispersed, and then the substrate is bonded and sealed. , Etc. can be illustrated. At this time, it is preferable to use a substrate having an electrode having a structure like a comb for driving a horizontal electric field as the substrate on one side. The spacer diameter at this time is preferably 1 μm to 30 μm, more preferably 2 μm to 10 μm. This spacer diameter determines the distance between the pair of substrates that sandwich the liquid crystal layer, that is, the thickness of the liquid crystal layer.

The manufacturing method of the board | substrate with a coating film of this invention irradiates the polarized ultraviolet-ray after apply | coating a polymer composition on a board | substrate and forming a coating film. Next, by heating, high-efficiency anisotropy is introduced into the side chain polymer film, and a substrate with a liquid crystal alignment film having a liquid crystal alignment 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 side chain photoreaction and 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 formed. After irradiation and then heating, a liquid crystal display element is formed.

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

  And in the coating film used for the method of this invention, the irradiation amount of the polarized ultraviolet-ray to a coating film, and the heating temperature in heat processing are optimized. Thereby, introduction of anisotropy into the coating film with high efficiency 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 such that the photosensitive group undergoes photocrosslinking reaction, photoisomerization reaction, or photofries rearrangement reaction in the coating film. Corresponds to the irradiation amount of polarized ultraviolet rays to optimize the amount. As a result of irradiating the coating film used in the present invention with polarized ultraviolet rays, if the photo-crosslinking reaction, photoisomerization reaction, or photo-fleece rearrangement reaction has few photosensitive groups in the side chain, the amount of photoreaction will not be sufficient. . In that case, sufficient self-organization does not proceed even after heating. On the other hand, as a result of irradiating polarized ultraviolet rays to the structure having a photocrosslinkable group in the coating film used in the present invention, the crosslinking reaction between the side chains is caused when the photosensitive group of the side chain undergoing the crosslinking reaction becomes excessive. Too much progress. In that case, the resulting film may become rigid and hinder the progress of self-assembly by subsequent heating. In addition, when the coating film used in the present invention is irradiated with polarized ultraviolet rays to the structure having the light Fleece rearrangement group, if the photosensitive group of the side chain that undergoes the light Fleece rearrangement reaction becomes excessive, the liquid crystallinity of the coating film Will drop too much. In that case, the liquid crystallinity of the obtained film is also lowered, which may hinder the progress of self-assembly by subsequent heating. Furthermore, when irradiating polarized ultraviolet light to a structure having a photo-fleece rearrangement group, if the amount of ultraviolet light irradiation is too large, the side-chain polymer is photodegraded, preventing the subsequent self-organization by heating. It may become.

  Therefore, in the coating film used in the present invention, the optimum amount of the photopolymerization reaction, photoisomerization reaction, or photofleece rearrangement reaction of the side chain photosensitive group by irradiation with polarized ultraviolet rays is the side chain polymer film. It is preferable to make it 0.1 mol%-40 mol% of the photosensitive group which has, and it is more preferable to set it as 0.1 mol%-20 mol%. By making the amount of the photo-reactive side chain photosensitive group within such a range, the self-organization in the subsequent heat treatment proceeds efficiently, and the formation of highly efficient anisotropy in the film is possible. Become.

  In the coating film used in the method of the present invention, by optimizing the irradiation amount of polarized ultraviolet rays, photocrosslinking reaction or photoisomerization reaction of photosensitive groups or photofleece rearrangement reaction in the side chain of the side chain polymer film Optimize the amount of. 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, a 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, the ultraviolet absorption in the direction parallel to the polarization direction of polarized ultraviolet light and the ultraviolet absorption in the vertical direction after irradiation with polarized ultraviolet light are measured for the coating film used in the present invention. 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 polarized ultraviolet rays and the ultraviolet absorbance in the direction perpendicular to the polarization direction of the polarized ultraviolet rays, is evaluated. Then, the maximum value of ΔA (ΔAmax) realized in the coating film used in the present invention and the irradiation amount of polarized ultraviolet light that realizes 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 on the basis of the amount of polarized ultraviolet rays to realize 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 realizing ΔAmax. More preferably, it is within the range of 50%. In the coating film used in the present invention, the irradiation amount of polarized ultraviolet rays within the range of 1% to 50% of the amount of polarized ultraviolet rays realizing ΔAmax is 0. 0% of the entire photosensitive group of the side chain polymer film. 1 mol% to 20 mol% corresponds to the amount of polarized ultraviolet light that undergoes a photocrosslinking reaction.

  From the above, in the production method of the present invention, in order to achieve highly efficient anisotropy introduction into the coating film, a suitable heating temperature as described above is set based on the liquid crystal temperature range of the side chain polymer. It is good to decide. Therefore, for example, when the liquid crystal temperature range of the side chain polymer used in the present invention is 100 ° C. to 200 ° C., the heating temperature after irradiation with polarized ultraviolet light is desirably 90 ° C. to 190 ° C. By doing so, greater anisotropy is imparted to the coating film used in the present invention.

  By doing so, the liquid crystal display element provided by the present invention exhibits high reliability against external stresses such as light and heat.

As described above, the lateral electric field drive type liquid crystal display element substrate manufactured by the method of the present invention or the lateral electric field drive type liquid crystal display element having the substrate has excellent reliability, large screen and high definition. It can be suitably used for LCD TVs.
EXAMPLES Hereinafter, although this invention is demonstrated using an Example, this invention is not limited to this Example.

The methacrylic monomers M1 and M2 used in the examples, HBAGE as a monomer having a crosslinking group, and A1 as a monomer having an amide group are shown below.
M1 and M2 were synthesized as follows. That is, M1 was synthesized by a synthesis method described in a patent document (WO2011-084546). M2 was synthesized by a synthesis method described in a patent document (Japanese Patent Laid-Open No. 9-118717).
Monomer A1 was synthesized by a synthesis method described in a patent document (WO2014 / 054785).
As HBAGE (hydroxybutyl acrylate glycidyl ether), a commercially available product was used.

In addition, the abbreviations of the reagents used in this example are shown below.
(Organic solvent)
THF: tetrahydrofuran.
NMP: N-ethyl-2-pyrrolidone.
BCS: Butyl cellosolve (polymerization initiator)
AIBN: 2,2′-azobisisobutyronitrile.
(Additive)
Phosphotungstic acid (PWA): Nippon Shin Metals

<Polymer synthesis example 1>
M1 (3.98 g), M2 (5.51 g), GMA (0.32 g), A1 (0.07 g) were dissolved in THF (40.0 g), and after deaeration with a diaphragm pump, AIBN (0.24 g) was added and deaeration was performed again. Thereafter, the mixture was reacted at 60 ° C. for 6 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to methanol (300 ml), and the resulting precipitate was filtered. This precipitate was washed with methanol and dried under reduced pressure to obtain methacrylate polymer powder P1.

<Example 1>
NMP (5.6 g) was added to the methacrylate polymer powder P1 (0.4 g) obtained in Polymer Synthesis 1, and dissolved by stirring for 30 minutes at room temperature. To this solution, PWA (0.004 g) was added and dissolved by stirring for 30 minutes at room temperature. Further, BCS (4.0 g) was added and stirred to obtain a polymer solution T1. This polymer solution was used as a liquid crystal aligning agent for forming a liquid crystal alignment film as it was.

<Examples 2-3>
The liquid crystal aligning agent T2-T3 of Examples 2-3 was obtained by adjusting the liquid crystal aligning agent using the composition shown in Table 1 in the same manner as in Example 1. Moreover, the liquid crystal aligning agent C1 of the comparative example 1 was obtained using the method similar to Example 1 except not adding PWA.

<Production of liquid crystal cell>
The liquid crystal aligning agent (T1) obtained in Example 1 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 a film thickness of 100 nm. A liquid crystal alignment film was formed. Next, the coating surface was irradiated with 313 nm ultraviolet rays through a polarizing plate at 15 mJ / cm 2 and then heated on a hot plate at 140 ° C. for 10 minutes to obtain a substrate with a liquid crystal alignment film. Two substrates with such a liquid crystal alignment film are prepared, a 6 μm spacer is set on the liquid crystal alignment film surface of one substrate, and the two substrates are combined so that the rubbing directions are parallel to each other. The periphery was sealed, and an empty cell with a cell gap of 4 μm was produced. Liquid crystal MLC-3019 (manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain a liquid crystal cell in which liquid crystals were aligned in parallel.
Using the liquid crystal aligning agents T2 to T3 obtained in Examples 2-3 and the liquid crystal aligning agent C1 obtained in Comparative Example 1, liquid crystal cells were similarly prepared.

<VHR evaluation>
VHR is evaluated by applying a voltage of 1 V to the obtained liquid crystal cell at a temperature of 70 ° C. for 60 μs, measuring the voltage after 16.67 ms and 1000 ms, and determining how much the voltage can be maintained. As calculated. VHR measured under the condition of 16.67 ms was designated as VHR1, and VHR measured under the condition of 1000 ms was designated as VHR2. The voltage holding ratio was measured using a voltage holding ratio measuring device VHR-1 manufactured by Toyo Technica.
Table 2 shows the results of VHR of the liquid crystal aligning agents of Examples 1 to 3 and Comparative Example.

  From Table 2, it can be seen that in Examples 1 to 3, by introducing phosphotungstic acid, both VHR1 and VHR2 are improved as compared with Comparative Example 1 in which the same additive is not introduced.

Claims (12)

[I] (A) a photosensitive side chain polymer that exhibits liquid crystallinity in a predetermined temperature range;
(B) A polymer composition containing a heteropolyacid, and (C) an organic solvent.   The polymer composition according to claim 1, wherein the component (A) has a photosensitive side chain that undergoes photocrosslinking, photoisomerization, or photofleece transition.   The polymer composition according to claim 1 or 2, wherein the heteropolyacid is phosphotungstic acid. The polymer composition according to claim 1 or 2, wherein the component (A) further has a side chain represented by the following formula (0).

In the formula, A and B are each independently a single bond, —O—, —CH ₂ —, —COO—, —OCO—, —CONH—, —NH—CO—, —CH═CH—CO—O—. Or -O-CO-CH = CH-;
S is an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced by a halogen group;
T is a single bond or an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced with a halogen group;
X is a single bond, —COO—, —OCO—, —N═N—, —CH═CH—, —C≡C—, —CH═CH—CO—O—, or —O—CO—CH═. When CH is 2 and the number of X is 2, X may be the same or different;
P and Q are each independently selected from the group consisting of a divalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof. Provided that when X is —CH═CH—CO—O— or —O—CO—CH═CH—, P or Q on the side to which —CH═CH— is bonded is an aromatic ring;
l1 is 0 or 1;
l2 is an integer from 0 to 2;
when l1 and l2 are both 0, A represents a single bond when T is a single bond;
when l1 is 1, B represents a single bond when T is a single bond;
G represents the following formulas (G-1), (G-2), (G-3) and (G-4).

(In the formula, a broken line represents a bond, R ⁵⁰ represents a group selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a phenyl group, and when there are a plurality of R ^50, they are the same or different from each other. T is an integer of 1 to 7, J represents O, S, NH or NR ⁵¹ , and R ⁵¹ represents a group selected from an alkyl group having 1 to 3 carbon atoms and a phenyl group). Group.   The polymer composition according to any one of claims 1 to 4, wherein the component (A) further has a side chain (b-2) having a group selected from a pyridyl group, an amide group, and a urethane group. . The component (A) is represented by the following formulas (1) to (6)
(In the formula, A, B and D are each independently a single bond, —O—, —CH ₂ —, —COO—, —OCO—, —CONH—, —NH—CO—, —CH═CH—CO; Represents —O— or —O—CO—CH═CH—;
S is an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced by a halogen group;
T is a single bond or an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced with a halogen group;
Y ₁ represents a ring selected from a monovalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring and alicyclic hydrocarbon having 5 to 8 carbon atoms, or the same or selected from those substituents. 2 to 6 different rings are groups bonded through a bonding group B, and the hydrogen atoms bonded to them are each independently —COOR ₀ (wherein R ₀ is a hydrogen atom or a carbon number of 1 to 5 represents an alkyl group), —NO ₂ , —CN, —CH═C (CN) ₂ , —CH═CH—CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms. May be substituted with an alkyloxy group;
Y ₂ is a group selected from the group consisting of a divalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof, The hydrogen atoms bonded to each independently represent —NO ₂ , —CN, —CH═C (CN) ₂ , —CH═CH—CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or 1 to 5 carbon atoms. May be substituted with an alkyloxy group of
R represents a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, or the same definition as Y ₁ ;
X is a single bond, —COO—, —OCO—, —N═N—, —CH═CH—, —C≡C—, —CH═CH—CO—O—, or —O—CO—CH═. When CH is 2 and the number of X is 2, X may be the same or different;
Cou represents coumarin-6-yl group or a coumarin-7-yl group, _-NO 2 are each a hydrogen atom bonded to them _{independently, -CN, -CH = C (CN} ) 2, -CH = CH- May be substituted with CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms;
one of q1 and q2 is 1 and the other is 0;
q3 is 0 or 1;
P and Q are each independently selected from the group consisting of a divalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof. Provided that when X is —CH═CH—CO—O— or —O—CO—CH═CH—, P or Q on the side to which —CH═CH— is bonded is an aromatic ring; When the number of P is 2 or more, the Ps may be the same or different, and when the number of Q is 2 or more, the Qs may be the same or different;
l1 is 0 or 1;
l2 is an integer from 0 to 2;
when l1 and l2 are both 0, A represents a single bond when T is a single bond;
when l1 is 1, B represents a single bond when T is a single bond;
H and I are each independently a group selected from a divalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, and combinations thereof. )
The polymer composition according to any one of claims 1 to 5, which has any one kind of photosensitive side chain selected from the group consisting of:

The component (A) is represented by the following formulas (21) to (31)
Wherein A and B have the same definition as above;
Y ₃ is a group selected from the group consisting of a monovalent benzene ring, naphthalene ring, biphenyl ring, furan ring, nitrogen-containing heterocycle, alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof. And each hydrogen atom bonded thereto may be independently substituted with —NO ₂ , —CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms;
R ₃ is a hydrogen atom, —NO ₂ , —CN, —CH═C (CN) ₂ , —CH═CH—CN, halogen group, monovalent benzene ring, naphthalene ring, biphenyl ring, furan ring, nitrogen-containing A heterocyclic ring, 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;
one of q1 and q2 is 1 and the other is 0;
l represents an integer of 1 to 12, m represents an integer of 0 to 2, provided that in formulas (23) to (24), the sum of all m is 2 or more, and formulas (25) to (26 ), The sum of all m is 1 or more, and m1, m2 and m3 each independently represents an integer of 1 to 3;
R ₂ is a hydrogen atom, —NO ₂ , —CN, a halogen group, a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a nitrogen-containing heterocyclic ring, 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 —)
The polymer composition according to any one of claims 1 to 6, which has any one liquid crystalline side chain selected from the group consisting of:

The process of apply | coating the polymer composition of any one of Claims 1-7 on the board | substrate which has a conductive film for a horizontal electric field drive, and forming a coating film;
[II] a step of irradiating the coating film obtained in [I] with polarized ultraviolet rays; and [III] a step of heating the coating film obtained in [II];
The manufacturing method of the board | substrate which has a liquid crystal aligning film which obtains the liquid crystal aligning film for horizontal electric field drive type liquid crystal display elements by which alignment control ability was provided by having. A substrate having a liquid crystal alignment film for a lateral electric field drive type liquid crystal display device produced by the method according to claim 8.   A lateral electric field drive type liquid crystal display device comprising the substrate according to claim 9. Preparing a substrate (first substrate) according to claim 9;
[I '] The process of apply | coating the polymer composition of any one of Claims 1-7 on a 2nd board | substrate, and forming a coating film;
[II ′] a step of irradiating the coating film obtained in [I ′] with polarized ultraviolet rays; and [III ′] a step of heating the coating film obtained in [II ′];
Obtaining a liquid crystal alignment film imparted with alignment control capability by having a second substrate having the liquid crystal alignment film; and [IV] liquid crystal alignment of the first and second substrates via liquid crystal A step of obtaining a liquid crystal display element by arranging the first and second substrates to face each other so that the films face each other;
A method for producing a liquid crystal display element, comprising obtaining a lateral electric field drive type liquid crystal display element.   A lateral electric field drive type liquid crystal display device manufactured by the method according to claim 11.