JP7046310B2 - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Description

The present invention relates to a novel polymer composition, a liquid crystal alignment film using the same, and a method for producing a substrate having the alignment film. Further, the present invention relates to a novel method for manufacturing a liquid crystal display element having excellent tilt angle characteristics.

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

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

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

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

Therefore, a photo-alignment method has been actively studied as another alignment treatment method for a liquid crystal alignment film without rubbing.

There are various photo-alignment methods, but 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 oriented according to the anisotropy.

As the main photo-alignment method, a decomposition type photo-alignment method is known. For example, the polyimide film is irradiated with polarized ultraviolet rays, and anisotropic decomposition is caused by utilizing the polarization direction dependence of the ultraviolet absorption of the molecular structure. Then, the liquid crystal is oriented by the polyimide left without decomposition (see Patent Document 1).

In addition, a photo-alignment method using a photo-bridge type is also known. For example, polyvinyl cinnamate is used to irradiate polarized ultraviolet rays to cause a dimerization reaction (crosslinking reaction) at the double bond portion of two side chains parallel to the polarization. Further, the pretilt angle is developed by irradiating the polarized ultraviolet rays in an oblique direction (see Non-Patent Document 1). When a side-chain polymer having coumarin in the side chain is used, polarized ultraviolet rays are irradiated to cause a photocrosslinking reaction in the coumarin portion of the side chain parallel to the polarization, and the liquid crystal is oriented in the direction parallel to the polarization direction. (See Non-Patent Document 2).

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

On the other hand, the liquid crystal alignment film also plays a role of imparting a certain tilt angle (pre-tilt angle) to the liquid crystal, and imparting the pre-tilt angle has become an important issue in the development of the liquid crystal alignment film (patented). Refer to Documents 3 to 6).

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

S. Kobayashi et al., Journal of Photopolymer Science and Technology, Vol.8, No.2, pp25-262 (1995). M. Shadt et al., Nature. Vol381, 212 (1996).

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

For example, in the decomposition type photo-orientation method described in Patent Document 1 described above, it is necessary to irradiate the polyimide film with ultraviolet light from a high-pressure mercury lamp having an output of 500 W for 60 minutes, which requires a long period of time and a large amount of ultraviolet irradiation. Become. Further, even in the case of the dimerization type or photoisomerization type photoalignment method, it may be necessary to irradiate a large amount of ultraviolet rays of about several J / cm ² to several tens J / cm ² . Further, in the case of the photocrosslinking type or the photoisomerization type photo-alignment method, the thermal stability and the photo-stability of the liquid crystal alignment are inferior. was there.

Therefore, in the photo-alignment method, it is required to improve the efficiency of the alignment process and to realize stable liquid crystal alignment, and the liquid crystal alignment film or liquid crystal can be highly efficiently imparted with high alignment control ability to the liquid crystal alignment film. An orienting agent is required.

The present invention relates to a substrate having a liquid crystal alignment film for a liquid crystal display element, which is provided with high efficiency and orientation control ability and has excellent tilt angle characteristics, and a longitudinal electrolytic drive type liquid crystal display element having the substrate (for example, twisted nematic (TN)). : Twisted Nematic (Va: Vertical Alignment) type liquid crystal display element, STN (Super-Twisted Nematic) type liquid crystal display element, ECB (Electrically Controlled Birefringence) type liquid crystal display element and OCB (Optically Compensated Bend) ) Type liquid crystal display element).
Further, an object of the present invention is, in addition to the above object, a vertical electrolytic drive type (for example, a twist nematic type liquid crystal display element, a VA type liquid crystal display element, an STN type liquid crystal display element, an ECB type liquid crystal display element) having an improved tilt angle characteristic. It is an object of the present invention to provide a display element and an OCB type liquid crystal display element) and a liquid crystal alignment film for the element. The vertical electrolysis drive type liquid crystal display element is a method of driving liquid crystal molecules by applying an electric field in a direction perpendicular to the substrate surface.

As a result of diligent studies to achieve the above problems, the present inventors have found the following inventions.
<1> A polymer composition containing (A) a photosensitive side-chain polymer that exhibits liquid crystallinity in a predetermined temperature range, (B) a reactive mesogen compound, and an organic solvent.

<2> In the above <1>, the reactive mesogen compound of the component (B) is preferably a compound represented by the following formula (I).
P-Sp-X-MG-X-Sp-P (I)
[In formula (I),
P is a polymerizable group
Sp is a spacer group having 1 to 20 carbon atoms.
X is a group or single bond selected from -O-, -S-, -CO-, -COO-, -OCO-, -OCO-O-.
The MG is a mesogen group or a mesogen support group, which groups are preferably selected according to Formula II below:
-(A ¹ -Z ¹ ) _m -A ² -Z ² -A ^3- (II)
(In formula (II), A ¹ , A ² and A ³ are mutually independent 1,4-phenylene groups, and one or more CH groups present in this group are also due to N. It may be replaced, or it is a 1,4-cyclohexylene group, one CH ₂ group present in this group or two non-adjacent CH ₂ groups are also due to O and / or S. It may be substituted, or it may be a 1,4-cyclohexenylene group or a naphthalene-2,6-diyl group, all of which are unsubstituted or one or more halogens. It may be substituted with a cyano or nitro group, or with an alkyl group, an alkoxy group or an alkanoyl group having 1 to 7 carbon atoms, and one or more H atoms in these groups are represented by F or Cl. May be replaced,
Z ¹ and Z ² are independent of -COO-, -OCO-, -CH ₂ CH _2- , -OCH _2- , -CH ₂ O-, -CH = CH-, -CC =, -CH. = CH-COO-, -OCO-CH = CH- or single bond, and m is 0, 1 or 2)].

<3> In the above <1> or <2>, the component (A) preferably has a photosensitive side chain that causes photocrosslinking, photoisomerization, or photofreeze transition.

<4> In the above <1> or <2>, the component (A) preferably has any one of the photosensitive side chains selected from the group consisting of the following formulas (1) to (6).

[In the formula, A, B, and D are independently single-bonded, -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 the hydrogen atom bonded to them may be replaced with a halogen group;
T is a single bond or an alkylene group having 1 to 12 carbon atoms, and the hydrogen atom bonded to them may be replaced with a halogen group;
Y ₁ represents a ring selected from a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring and an alicyclic hydrocarbon having 5 to 8 carbon atoms, or the same or selected from their substituents. It is a group consisting of 2 to 6 different rings bonded via a bonding group B, and the hydrogen atoms bonded to them are independently −COOR ₀ (in the formula, R ₀ is an alkyl having 1 to 5 carbon atoms. (Representing a 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 alkyloxy group having 1 to 5 carbon atoms. May be replaced with;
Y ₂ is a group selected from the group consisting of a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon having 5 to 8 carbon atoms, and a combination thereof. The hydrogen atoms bonded to are independently -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 of;
R represents an alkoxy group having ₁ to 6 carbon atoms or represents the same definition as Y1;
X is a single bond, -COO-, -OCO-, -N = N-, -CH = CH-, -C≡C-, -CH = CH-CO-O-, or -O-CO-CH = Representing CH-, when the number of Xs is 2, the Xs may be the same or different;
Cou represents a coumarin-6-yl group or a coumarin-7-yl group, and the hydrogen atoms bonded to them are independently -NO ₂ , -CN, -CH = C (CN) ₂ , -CH = CH-. It 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 independently selected from the group consisting of a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon having 5 to 8 carbon atoms, and a combination thereof. It is a group; however, when X is -CH = CH-CO-O-, -O-CO-CH = CH-, P or Q on the side to which -CH = CH- is bound is an aromatic ring;
l1 is 0 or 1;
l2 is an integer from 0 to 2;
When both l1 and l2 are 0, A also represents a single bond when T is a single bond;
When l1 is 1, B also represents a single bond when T is a single bond;
H and I are groups independently selected from a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and a combination thereof. "

<5> In any of the above <1> to <4>, the component (A) further has any one liquid crystal side chain selected from the group consisting of the following formulas (21) to (30). Is good.
In the formula, A, B, R, q1 and q2 have the same definitions as above;
_Y3 is a group selected from the group consisting of monovalent benzene rings, naphthalene rings, biphenyl rings, furan rings, nitrogen-containing heterocycles, alicyclic hydrocarbons having 5 to 8 carbon atoms, and combinations thereof. Yes, the hydrogen atoms attached to them 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 contains a hydrogen atom, -NO ₂ , -CN, -CH = C (CN) ₂ , -CH = CH-CN, a halogen group, a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, and nitrogen. Represents a heterocycle, an alicyclic hydrocarbon having 5 to 8 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms;
l represents an integer of 1 to 12, m represents an integer of 0 to 2, but in equations (23) to (26), the sum of all m is 2 or more, and m1, m2, and m3 are. 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 heterocycle, and an alicyclic hydrocarbon having 5 to 8 carbon atoms. And represents an alkyl group or an alkyloxy group;
Z ₁₁ and Z ₁₂ represent a single bond, -CO-, -CH ₂ O-, -CH = N-, -CF _2- .

<6> [I] A step of applying the polymer composition according to any one of <1> to <5> above onto a substrate having an electrode for driving a liquid crystal display to form a coating film;
[II] A step of irradiating the coating film obtained in [I] with ultraviolet rays polarized from an oblique direction; and [III] a step of heating the coating film obtained in [II].
A method for manufacturing a substrate having the liquid crystal alignment film, which obtains a liquid crystal alignment film for a vertical electrolysis-driven liquid crystal display element to which an orientation control ability is imparted.
<7> A substrate having a liquid crystal alignment film for a vertical electrolytic drive type liquid crystal display element manufactured by the manufacturing method described in <6> above.
<8> A vertical electrolysis-driven liquid crystal display element having the substrate of <7> above.
<9> A twisted nematic type liquid crystal display element or an OCB type liquid crystal display element having the substrate of <7> above.

<10> Step of preparing the substrate (first substrate) of the above <7>;
A step of obtaining a second substrate by using the steps [I] to [III] of the above <6>; and [IV] so that the liquid crystal alignment films of the first and second substrates face each other via the liquid crystal. , A step of arranging the first and second substrates facing each other to obtain a liquid crystal display element;
A method for manufacturing a liquid crystal display element, wherein a vertical electrolysis-driven liquid crystal display element is obtained.
<11> In the [IV] step, the first and second substrates are arranged facing each other so that the orientation directions are orthogonal to each other so that the liquid crystal alignment films of the first and second substrates face each other via the liquid crystal. A method for manufacturing a twist nematic type liquid crystal display element, which is a process of obtaining a liquid crystal display element.
<12> A vertical electrolysis drive type liquid crystal display element manufactured by the above <10>.
<13> The twist nematic type liquid crystal display element manufactured by the above <11>.

INDUSTRIAL APPLICABILITY According to the present invention, a substrate having a liquid crystal alignment film having high efficiency and excellent tilt angle characteristics and a longitudinal electrolytically driven liquid crystal display element having the substrate (for example, twist nematic type liquid crystal display element, VA type). A liquid crystal display element, an STN type liquid crystal display element, an ECB type liquid crystal display element, and an OCB type liquid crystal display element) can be provided.
Since the vertical electrolytic drive type liquid crystal display element manufactured by the method of the present invention is provided with the orientation control ability with high efficiency, the display characteristics are not impaired even if it is continuously driven for a long time.

As a result of diligent research, the present inventor has obtained the following findings and has completed the present invention.
The polymer composition used in the production method of the present invention has a photosensitive side-chain polymer (hereinafter, also simply referred to as a side-chain polymer) capable of exhibiting liquid liquidity, and the polymer composition. The coating film obtained by using a substance is a film having a photosensitive side chain polymer capable of exhibiting liquidity. This coating film is not subjected to a rubbing treatment, but is subjected to an orientation treatment by polarization irradiation. Then, after the polarization irradiation, the side chain type polymer film is heated to obtain a coating film having an orientation control ability (hereinafter, also referred to as a liquid crystal alignment film). At this time, the slight anisotropy developed by the polarization irradiation becomes the driving force, and the liquid crystal side chain polymer itself is efficiently reoriented by self-assembly. As a result, highly efficient alignment processing can be realized as a liquid crystal alignment film, and a liquid crystal alignment film with high orientation control ability can be obtained.

Hereinafter, embodiments of the present invention will be described in detail.

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

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

The structure of the polymer has, for example, a main chain and a side chain bonded to the main chain, and the side chain contains a mesogen component such as a biphenyl group, a terphenyl group, a phenylcyclohexyl group, a phenylbenzoate group, and an azobenzene group, and a tip thereof. It has a structure having a photosensitive group bonded to a portion and undergoing a cross-linking reaction or an isomerization reaction in response to light, a main chain and a side chain bonded to the main chain, and the side chain also serves as a mesogen component. It can be a structure having a phenylbenzoate group that undergoes a photofreeze rearrangement reaction.

More specific examples of the structure of the photosensitive side chain polymer capable of exhibiting liquidity include hydrocarbons, (meth) acrylates, itaconates, fumarates, maleates, α-methylene-γ-butyrolactone, styrene, and vinyl. , Maleimide, Norbornen and other radically polymerizable groups and a main chain composed of at least one selected from the group consisting of siloxane, and a photosensitive side chain composed of at least one of the following formulas (1) to (6). It is preferable that the structure has.

In the formula, A, B, and D are independently single-bonded, -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 the hydrogen atom bonded to them may be replaced with a halogen group;
T is a single bond or an alkylene group having 1 to 12 carbon atoms, and the hydrogen atom bonded to them may be replaced with a halogen group;
Y ₁ represents a ring selected from a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring and an alicyclic hydrocarbon having 5 to 8 carbon atoms, or the same or selected from their substituents. It is a group consisting of 2 to 6 different rings bonded via a bonding group B, and the hydrogen atoms bonded to them are independently −COOR ₀ (in the formula, R ₀ is an alkyl having 1 to 5 carbon atoms. (Representing a 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 alkyloxy group having 1 to 5 carbon atoms. May be replaced with;
Y ₂ is a group selected from the group consisting of a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon having 5 to 8 carbon atoms, and a combination thereof. The hydrogen atoms bonded to are independently -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 of;
R represents an alkoxy group having ₁ to 6 carbon atoms or represents the same definition as Y1;
X is a single bond, -COO-, -OCO-, -N = N-, -CH = CH-, -C≡C-, -CH = CH-CO-O-, or -O-CO-CH = Representing CH-, when the number of Xs is 2, the Xs may be the same or different;
Cou represents a coumarin-6-yl group or a coumarin-7-yl group, and the hydrogen atoms bonded to them are independently -NO ₂ , -CN, -CH = C (CN) ₂ , -CH = CH-. It 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 independently selected from the group consisting of a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon having 5 to 8 carbon atoms, and a combination thereof. It is a group; however, when X is -CH = CH-CO-O-, -O-CO-CH = CH-, P or Q on the side to which -CH = CH- is bound is an aromatic ring;
l1 is 0 or 1;
l2 is an integer from 0 to 2;
When both l1 and l2 are 0, A also represents a single bond when T is a single bond;
When l1 is 1, B also represents a single bond when T is a single bond;
H and I are groups independently selected from a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and a combination thereof.

The side chain is preferably any one of the photosensitive side chains selected from the group consisting of the following formulas (7) to (10).
In the formula, A, B, D, Y ₁ , X, Y ₂ , and R have the same definition as above;
l represents an integer from 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 from 0 to 12 (where B is a single bond when n = 0).

The side chain is preferably any one of the photosensitive side chains selected from the group consisting of the following formulas (11) to (13).
In the formula, A, X, l, m and R have the same definitions as above.

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

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

The side chain is preferably a photosensitive side chain represented by the following formula (18) or (19).
In the formula, A, B, Y ₁ , q1, q2, m1 and m2 have the same definitions 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 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 definitions as above.

Further, the side chain type polymer (A) preferably has any one liquid crystal side chain selected from the group consisting of the following formulas (21) to (30).
In the formula, A, B, R, q1 and q2 have the same definitions as above;
_Y3 is a group selected from the group consisting of monovalent benzene rings, naphthalene rings, biphenyl rings, furan rings, nitrogen-containing heterocycles, alicyclic hydrocarbons having 5 to 8 carbon atoms, and combinations thereof. Yes, the hydrogen atoms attached to them 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 contains a hydrogen atom, -NO ₂ , -CN, -CH = C (CN) ₂ , -CH = CH-CN, a halogen group, a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, and nitrogen. Represents a heterocycle, an alicyclic hydrocarbon having 5 to 8 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms;
l represents an integer of 1 to 12, m represents an integer of 0 to 2, but in equations (23) to (26), the sum of all m is 2 or more, and m1, m2, and m3 are. 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 heterocycle, and an alicyclic hydrocarbon having 5 to 8 carbon atoms. And represents an alkyl group or an alkyloxy group;
Z ₁₁ and Z ₁₂ represent a single bond, -CO-, -CH ₂ O-, -CH = N-, -CF _2- .

<< Manufacturing method of photosensitive side chain polymer >>
The photosensitive side chain polymer capable of exhibiting the liquidity can be obtained by polymerizing the photoreactive side chain monomer having the photosensitive side chain and the liquid crystal side chain monomer.

[Photoreactive side chain monomer]
The photoreactive side chain monomer is a monomer capable of forming a polymer having a photosensitive side chain at a side chain portion of the polymer when the polymer is formed.
As the photoreactive group of the side chain, the following structure and its derivative are preferable.

More specific examples of photoreactive side chain monomers include radical polymerizable groups such as hydrocarbons, (meth) acrylates, itaconates, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, norbornene. A polymerizable group composed of at least one selected from the group consisting of siloxane and a photosensitive side chain composed of at least one of the above formulas (1) to (6), preferably, for example, the above formula (7). )-(10), a photosensitive side chain consisting of at least one of the above formulas (11) to (13), a photosensitive side chain consisting of at least one of the above formulas (14) or (15). Sexual side chain, photosensitive side chain represented by the above formula (16) or (17), photosensitive side chain represented by the above formula (18) or (19), photosensitive side chain represented by the above formula (20). It is preferably a structure having a sex side chain.

As such a photoreactive side chain monomer, one that exhibits a dimerization reaction or an isomerization reaction when irradiated with polarized ultraviolet rays is preferable. Examples of such a monomer include a monomer selected from the following formulas M1-1 to M1-22.

(In the formula, M1 is a hydrogen atom or a methyl group, and s1 is a natural number of 2 to 9 representing the number of methylene groups.)

(In the formula, R is an alkoxy group having 1 to 6 carbon atoms, M1 is a hydrogen atom or a methyl group, and s1 represents the number of methylene groups, which is a natural number of 2 to 9).

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

More specific examples of the liquid crystal side chain monomer include hydrocarbons, (meth) acrylates, itaconates, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, norbornene and other radically polymerizable groups. It is preferable that the structure has a polymerizable radical composed of at least one selected from the group consisting of siloxane and a side chain composed of at least one of the above formulas (21) to (30).

As a specific example of such a liquid crystal monomer, for example, a monomer represented by a formula selected from the group consisting of the following formulas M2-1 to M2-10 can be used.

(In the formula, M1 is a hydrogen atom or a methyl group, R is an alkoxy group having 1 to 6 carbon atoms, M1 is a hydrogen atom or a methyl group, and s1 represents the number of methylene groups of 2 to 9. It is a natural number.)

(A) The side chain type polymer can be obtained by the copolymerization reaction of the photoreactive side chain monomer exhibiting the liquid crystal property described above. Further, it can be obtained by copolymerizing a photoreactive side chain monomer that does not exhibit liquidity and a liquid crystal side chain monomer, or by copolymerizing a photoreactive side chain monomer that exhibits liquidity and a liquid crystal side chain monomer. can. Furthermore, it can be copolymerized with other monomers as long as the liquid crystallinity is not impaired.

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

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

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

Examples of the 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 and tert-butyl. Methacrylate, Cyclohexyl methacrylate, Isobornyl methacrylate, 2-Methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2-ethoxyethyl methacrylate, Tetrahydrofurfuryl methacrylate, 3-Methoxybutyl methacrylate, 2-Methyl-2-adamantyl methacrylate, 2- Examples thereof include propyl-2-adamantyl methacrylate, 8-methyl-8-tricyclodecyl methacrylate, 8-ethyl-8-tricyclodecyl methacrylate and the like.

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

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

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

The content of the photoreactive side chain in the side chain polymer of the present invention is preferably 10 mol% to 100 mol%, more preferably 20 mol% to 95 mol%, and more preferably 30 mol% from the viewpoint of liquid crystal orientation. It is more preferably ~ 90 mol%.

The content of the liquid crystal side chain in the side chain type polymer of the present invention is preferably 90 mol% or less, more preferably 5 mol% to 80 mol%, and 10 mol% to 70 mol% from the viewpoint of liquid crystal orientation. Is more preferable.

The side chain type polymer of the present invention may contain other side chains other than the photoreactive side chain and the liquid crystal side chain. The content is the remaining portion when the total content of the photoreactive side chain and the liquid crystal side chain is less than 100%.

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

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

The radical thermal polymerization initiator is a compound that generates radicals by heating to a temperature higher than the decomposition temperature. Examples of such radical thermal polymerization initiators include ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), diacyl peroxides (acetyl peroxide, benzoyl peroxide, etc.), and hydroperoxides (peroxidation). Hydrogen, tert-butylhydroxide, cumenehydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyketals (dibutylperoxycyclohexane, etc.) Etc.), alkyl peresters (peroxyneodecanic acid-tert-butyl ester, peroxypivalic acid-tert-butyl ester, peroxy2-ethylcyclohexanoic acid-tert-amyl ester, etc.), persulfates (potassium persulfate, etc.) Examples thereof include sodium persulfate, ammonium persulfate, etc.) and azo compounds (azobisisobutyronitrile, and 2,2'-di (2-hydroxyethyl) azobisisobutyronitrile, etc.). Such a radical thermal polymerization initiator may be used alone 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 and 2-hydroxy. -2-Methylpropiophenone, 2-Hydroxy-2-methyl-4'-isopropylpropiophenone, 1-hydroxycyclohexylphenylketone, isopropylbenzoin ether, isobutylbenzoin ether, 2,2-diethoxyacetophenone, 2,2 -Dimethoxy-2-phenylacetophenone, camphorquinone, benzanthron, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1-( 4-Molholinophenyl) -butanone-1, 4-ethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 4,4'-di (t-butylperoxycarbonyl) benzophenone, 3,4,4'-tri (3,4'-tri ( t-butylperoxycarbonyl) benzophenone, 2,4,6-trimethylbenzoyldiphenylphosphinoxide, 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'-Methtylyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4'-pentyloxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 4- [P-N, N-di (ethoxycarbonylmethyl)]-2,6-di (trichloromethyl) -s-triazine, 1,3-bis (trichloromethyl) -5- (2'-chlorophenyl) -s- Triazine, 1,3-bis (trichloromethyl) -5- (4'-methoxyphenyl) -s-triazine, 2- (p-dimethylaminostyryl) benzoxazole, 2- (p-dimethylaminostyryl) benzthiazole, 2-Mercaptobenzothiazole, 3,3'-carbonylbis (7-diethylaminocoumarin), 2- (o-chlorophenyl) -4,4', 5,5'-tetraphenyl-1,2'-biimidazole, 2 , 2'-bi Su (2-chlorophenyl) -4,4', 5,5'-tetrax (4-ethoxycarbonylphenyl) -1,2'-biimidazole, 2,2'-bis (2,4-dichlorophenyl) -4, 4', 5,5'-tetraphenyl-1,2'-biimidazole, 2,2'bis (2,4-dibromophenyl) -4,4', 5,5'-tetraphenyl-1,2' -Bimidazole, 2,2'-bis (2,4,6-trichlorophenyl) -4,4', 5,5'-tetraphenyl-1,2'-biimidazole, 3- (2-methyl-2) -Dimethylaminopropionyl) carbazole, 3,6-bis (2-methyl-2-morpholinopropionyl) -9-n-dodecylcarbazole, 1-hydroxycyclohexylphenylketone, bis (5-2,4-cyclopentadiene-1- Il) -bis (2,6-difluoro-3- (1H-pyrrole-1-yl) -phenyl) titanium, 3,3', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 3,3 ', 4,4'-tetra (t-hexylperoxycarbonyl) benzophenone, 3,3'-di (methoxycarbonyl) -4,4'-di (t-butylperoxycarbonyl) benzophenone, 3,4'-di ( Methoxycarbonyl) -4,3'-di (t-butylperoxycarbonyl) benzophenone, 4,4'-di (methoxycarbonyl) -3,3'-di (t-butylperoxycarbonyl) benzophenone, 2- (3- (3-) Methyl-3H-benzothiazole-2-iriden) -1-naphthalen-2-yl-etanone, or 2- (3-methyl-1,3-benzothiazole-2 (3H) -iriden) -1- (2-) Benzoyl) Etanone and the like can be mentioned. These compounds may be used alone or in admixture of two or more.

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

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

N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactum, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide , Gamma-butylollactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethylamyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cell solve, ethyl cell solve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl Carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl Ether, Diethylene Glycol, Diethylene Glycol Monoacetate, Diethylene Glycol Dimethyl Ether, Dipropylene Glycol Monoacetate Monomethyl Ether, Dipropylene Glycol Monomethyl Ether, Dipropylene Glycol Monoethyl Ether, Dipropylene Glycol Monoacetate Monoethyl Ether, Dipropylene Glycol Monopropyl Ether, Dipropylene Glycol Monoacetate Monopropyl Ether, 3-Methyl-3-methoxybutyl Acetate, Tripropylene Glycol Methyl Ether, 3-Methyl-3-methoxybutanol, Diisopropyl Ether, Ethyl Isobutyl Ether, Diisobutylene, Amyl Acetate, Butyl Butyrate, Butyl Ether , Diisobutylketone, methylcyclohexene, propyl ether, dihexyl ether, dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, acetic acid Ethyl, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropion Acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglime, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N, N-dimethylpropanamide, 3- Examples thereof include ethoxy-N, N-dimethylpropanamide, 3-butoxy-N, N-dimethylpropanamide and the like.

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

The polymerization temperature at the time of radical polymerization can be selected from any temperature of 30 ° 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 will be difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution will be too high and uniform stirring will be 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 reaction can be carried out at a high concentration and then an organic solvent can be added.

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

[Recovery of polymer]
When recovering the produced polymer from the reaction solution of the photosensitive side-chain polymer that can exhibit liquidity obtained by the above reaction, the reaction solution is put into a poor solvent and their weights are increased. The coalescence may be precipitated. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, heptane, butyl cellsolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, water and the like. The polymer which has been put into a poor solvent and precipitated can be collected by filtration and then dried at room temperature or by heating under normal pressure or reduced pressure. Further, by re-dissolving the polymer recovered by precipitation in an organic solvent and repeating the operation of re-precipitation recovery 2 to 10 times, impurities in the polymer can be reduced. Examples of the poor solvent at this time include alcohols, ketones, hydrocarbons and the like, and it is preferable to use three or more kinds of poor solvents selected from these because the efficiency of purification 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, the workability at the time of forming the coating film, and the uniformity of the coating film. The weight average molecular weight obtained is preferably 2000 to 10000, more preferably 5000 to 100,000.

<< (B) RM (Reactive Mesogen Compound) >>
In a preferred embodiment of the present invention, the reactive mesogen compound used for the liquid crystal alignment agent is a compound represented by the following formula I:
P-Sp-X-MG-X-Sp-P (I)
[In formula (I),
P is a polymerizable group
Sp is a spacer group having 1 to 20 carbon atoms.
X is a group or single bond selected from -O-, -S-, -CO-, -COO-, -OCO-, -OCO-O-.
The MG is a mesogen group or a mesogen supporting group, and this group is preferably selected according to the following formula (II):
-(A ¹ -Z ¹ ) _m -A ² -Z ² -A ^3- (II)
(During the ceremony,
A ¹ , A ² and A ³ are independent of each other and are 1,4-phenylene groups, and one or more CH groups present in this group may also be replaced by N. Alternatively, it may be a 1,4-cyclohexylene group, in which one CH ₂ group or two non-adjacent CH ₂ groups present in this group may also be replaced by O and / or S. Alternatively, it may be a 1,4-cyclohexenylene group or a naphthalene-2,6-diyl group, all of which are unsubstituted, or by one or more halogen, cyano or nitro groups, or. It may be substituted with an alkyl group having 1 to 7 carbon atoms, an alkoxy group or an alkanoyl group, and one or more H atoms in these groups may be substituted with F or Cl.
Z ¹ and Z ² are independent of -COO-, -OCO-, -CH ₂ CH _2- , -OCH _2- , -CH ₂ O-, -CH = CH-, -CC =, -CH. = CH-COO-, -OCO-CH = CH- or single bond, and m is 0, 1 or 2)].

A polymerizable mixture containing at least two reactive mesogen compounds, wherein at least one of them is a compound represented by the formula I, is particularly suitable.
Bicyclic and tricyclic mesogen compounds are suitable.
The halogen is preferably F or Cl.

Among the compounds represented by formula I, MG is in formula II, Z ¹ and Z ² are -COO-, -OCO-, -CH ₂ -CH _2- , -CH = CH-COO-, -OCO-. Compounds with CH = CH- or a single bond are particularly suitable.

A small group of suitable mesogen groups represented by formula II is shown below. For brevity, in these groups, Phe is 1,4-phenylene and PheL is 1,4-phenylene substituted by at least one group L, where L is F, Cl or It is an alkyl, alkoxy or alkanoyl group that is CN or has 1 to 4 carbon atoms and may be fluorinated, and Cyc is trans-1,4-cyclohexylene.

In these suitable groups, Z ¹ and Z ² have the meanings shown for Formula I above. Preferably, Z ¹ and Z ² are -COO-, -OCO-, -CH ₂ CH _2- or -CH = CH-COO-.
L is preferably F, Cl, CN, NO ₂ , CH ₃ , C ₂ H ₅ , OCH ₃ , OC ₂ H ₅ , COCH ₃ , COC ₂ H ₅ , CF ₃ , OCF ₃ , OCHF ₂ , OCF ₅ , In particular, F, Cl, CN, CH ₃ , C ₂ H ₅ , OCH ₃ , COCH ₃ and OCF ₃ , most preferably F, CH ₃ , OCH ₃ and COCH ₃ .

Compounds for which MG is selected from the following formula are particularly suitable:

In these equations, L has the above meaning and r is 0, 1 or 2.
In these preferred formulas, the group:

Is very preferable,

And also again

In these groups, L independently has one of the above meanings.
The R present in these suitable compounds has one of the meanings shown for P- (Sp) _n- .

P is preferably CH ₂ = CW-COO-, WCH = CH-O-,

Or CH ₂ = CH-phenyl- (O) _K , where W is H, CH ₃ or Cl, and k is 0 or 1.

P is particularly preferably a vinyl group, an acrylate group, a methacrylate group, a propenyl group or an epoxy group, and very particularly preferably an acrylate group.

As the spacer group Sp, all groups known to those skilled in the art can be used for this purpose. The spacer group Sp is preferably attached to the polymerizable group P by an ester or ether group or by a single bond. The spacer group Sp preferably has 1 to 20 carbon atoms, particularly 1 to 12 carbon atoms, and one CH ₂ or _two or more non-adjacent CHs present in the group. However, -O-, -S-, -NH-, -N (CH ₃ )-, -CO-, -O-CO-, -S-CO-, -O-COO-, -CO-S-, A linear or branched alkylene group that may be replaced by -CO-O-, -CH (halogen)-, -CH (CN)-, -CH = CH- or -C≡C-. ..

Typical spacer groups are, for example,-(CH ₂ ) ₀ -,-(CH ₂ CH ₂ O) _r -CH ₂ CH _{2-, -CH 2 CH 2-S-CH 2 CH 2 - or - CH 2} CH ₂ -NH-CH ₂ CH _2- , in these groups, o is an integer of 2-12 and r is an integer of 1-3.

Suitable spacer groups include, for example, ethylene, propylene, butylene, pentylene, hexylene, heptene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylene-thioethylene, ethylene-N-methylimiminoethylene and 1-Methylalkylene.

In Formula I, the two Ps, Sps and Xs may be the same or different, respectively.

Representative examples of the polymerizable mesogen compound represented by the formula I are shown in the following compound list. However, this list is merely exemplary and does not limit the scope of the invention.

In these compounds, x and y are independently 1-12, M ¹ is a hydrogen atom or a methyl group, and L ¹ and L ² are independently H, halogen or CN, respectively. Alternatively, it is an alkyl group, an alkoxy group or an alkanoyl group having 1 to 7 carbon atoms.
These compounds are known in the literature or are commercially available.

<< (C) Organic Solvent >>
The organic solvent used in the polymer composition used in the present invention is not particularly limited as long as it is an organic solvent that dissolves the resin component. Specific examples are given below.
N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-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, ethylamyl ketone, methylnonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethylene carbonate, propylene carbonate, diglyme, 4-hydroxy-4-methyl-2-pentanone, propylene glycol mono Acetate, 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, Examples thereof include dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether and the like. These may be used alone or in combination.

<Polymer composition>
The polymer composition is applied to the side of the substrate on which the electrodes are formed.
The polymer composition used in the production method of the present invention is (A) a photosensitive side chain polymer that exhibits liquid crystallinity in a predetermined temperature range, (B) a reactive mesogen compound, and (C) an organic substance. Contains solvent.

[Preparation of polymer composition]
The polymer composition used in the present invention is preferably prepared as a coating liquid so as to be suitable for forming a liquid crystal alignment film. That is, the polymer composition used in the present invention is preferably prepared as a solution in which a resin component for forming a resin film is dissolved in an organic solvent. Here, the resin component is a resin component containing a photosensitive side-chain type polymer capable of exhibiting liquid crystallinity as described above. At that time, the content of the resin component is preferably 1% 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, all of the above-mentioned resin components may be photosensitive side-chain polymers capable of exhibiting the above-mentioned liquid crystal properties, but the liquid crystal expression ability and the photosensitive performance are not impaired. Other polymers may be mixed in the range. At that time, the content of the other polymer in the resin component is 0.5% by mass to 80% by mass, preferably 1% by mass to 50% by mass.
Examples of such other polymers include polymers made of poly (meth) acrylate, polyamic acid, polyimide, etc., and are not photosensitive side-chain polymers capable of exhibiting liquid crystallinity.

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

Specific examples of the solvent (poor solvent) for improving the uniformity of the film thickness and the surface smoothness include the following.
For example, isopropyl alcohol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol mono. Isopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether , Dipropylene glycol monomethyl ether, Dipropylene glycol monoethyl ether, Dipropylene glycol monoacetate monoethyl ether, Dipropylene glycol monopropyl ether, Dipropylene glycol monoacetate monopropyl ether, 3-Methyl-3-methoxybutyl acetate, Tri Propylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethylisobutyl ether, diisobutylene, amylacetate, butylbutyrate, butyl ether, diisobutylketone, 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, 3- Methyl 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 levels of 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, etc. Examples thereof include a solvent having a surface tension.

These poor solvents may be used alone or in admixture of a plurality of types. When a solvent as described above is used, it is preferably 5% by mass to 80% by mass, 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 the uniformity of the film thickness and the surface smoothness include a fluorine-based surfactant, a silicone-based surfactant, and a nonion-based surfactant.
More specifically, for example, Ftop (registered trademark) 301, EF303, EF352 (manufactured by Tochem Products), Megafuck (registered trademark) F171, F173, R-30 (manufactured by DIC), Florard FC430, FC431. (Sumitomo 3M), Asahi Guard (registered trademark) AG710 (Asahi Glass), Surflon (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, SC106 (AGC Seimi Chemical), etc. Will be. The ratio of these surfactants used is preferably 0.01 parts by mass to 2 parts by mass, and 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. It is a mass part.

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

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

Specific examples of the epoxy group-containing compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-Hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N', N',-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N', N',-tetraglycidyl-4, 4'-diaminodiphenylmethane Etc. are exemplified.

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

A photosensitizer can also be used as the additive. Colorless sensitizers and triplet sensitizers are preferred.

Photosensitizers include aromatic nitro compounds, coumarin (7-diethylamino-4-methylcoumarin, 7-hydroxy4-methylcoumarin), ketocoumarin, carbonylbiscmarin, aromatic 2-hydroxyketone, and amino substitutions. , Aromatic 2-hydroxyketone (2-hydroxybenzophenone, mono- or di-p- (dimethylamino) -2-hydroxybenzophenone), acetophenone, anthraquinone, xanthone, thioxanthone, benzanthron, thiazolin (2-benzoylmethylene-3) -Methyl-β-naphthiazolin, 2- (β-naphthoylmethylene) -3-methylbenzothiazolin, 2- (α-naphthoylmethylene) -3-methylbenzothiazolin, 2- (4-biphenoylmethylene)- 3-Methylbenzothiazolin, 2- (β-naphthoylmethylene) -3-methyl-β-naphthiazoline, 2- (4-biphenoylmethylene) -3-methyl-β-naphthiazoline, 2- (p-fluoro) Benzoylmethylene) -3-methyl-β-naphthiazolin), oxazoline (2-benzoylmethylene-3-methyl-β-naphthoxazoline, 2- (β-naphthoylmethylene) -3-methylbenzoxazoline, 2- (α) -Naftylmethylene) -3-methylbenzoxazoline, 2- (4-biphenoylmethylene) -3-methylbenzoxazoline, 2- (β-naphthoylmethylene) -3-methyl-β-naphthooxazolin, 2-( 4-Bifenoylmethylene) -3-methyl-β-naphthoxazoline, 2- (p-fluorobenzoylmethylene) -3-methyl-β-naphthoxazoline), benzothiazole, nitroaniline (m- or p-nitroaniline, 2,4,6-trinitroaniline) or nitroacenaften (5-nitroacenaften), (2-[(m-hydroxy-p-methoxy) styryl] benzothiazole, benzoinalkyl ether, N-alkylated phthalone, Acetphenon ketal (2,2-dimethoxyphenyletanone), naphthalene, anthracene (2-naphthalene methanol, 2-naphthalene carboxylic acid, 9-anthracene methanol, and 9-anthracene carboxylic acid), benzopyrane, azoindrinsin, merocmarin, etc. be.
Preferred are aromatic 2-hydroxyketone (benzophenone), coumarin, ketocoumarin, carbonylbisquemarin, acetophenone, anthraquinone, xanthone, thioxanthone, and acetophenone ketal.

The method for manufacturing a substrate having a liquid crystal alignment film of the present invention is
[I] A polymer composition containing (A) a photosensitive side-chain polymer that exhibits liquid crystallinity in a predetermined temperature range, (B) a reactive mesogen compound, and an organic solvent is used as an electrode for driving a liquid crystal display. Step of applying on the substrate 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.
Vertical electrolytic drive type liquid crystal display element (for example, twist nematic type liquid crystal display element, vertical alignment type liquid crystal display element, STN type liquid crystal display element, ECB type liquid crystal display element and OCB type liquid crystal display element to which orientation control ability is imparted by the above step. A liquid crystal alignment film for a display element) 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 vertical electrolytic drive type liquid crystal display element (for example, a twist nematic type liquid crystal display element, a vertically oriented liquid crystal display element) can be prepared. , STN type liquid crystal display element, ECB type liquid crystal display element and OCB type liquid crystal display element) can be obtained.
As the second substrate, by using the above steps [I] to [III], it is possible to obtain a second substrate having a liquid crystal alignment film to which the orientation control ability is imparted.

The manufacturing method of the vertical electrolysis drive type liquid crystal display element is as follows.
[IV] A step of arranging the first and second substrates obtained above so as to face each other so that the liquid crystal alignment films of the first and second substrates face each other via the liquid crystal display;
Have. At that time, the substrates with the first and second alignment films obtained above having a tilt angle of 10 to 50 degrees are parallel and the same direction (parallel orientation) in the rubbing direction (alignment of the liquid crystal display). If they are arranged in such a manner, an OCB type liquid crystal display element can be obtained. When the same method is performed using two substrates with an alignment film having a tilt angle of 80 to 90 degrees, a vertically oriented liquid crystal display element can be obtained. A twisted nematic liquid crystal display element can be obtained if the rubbing directions are arranged so as to be orthogonal to each other, that is, twisted by about 90 degrees, and an STN type liquid crystal display element can be obtained if the rubbing directions are arranged so as to be twisted by about 260 degrees. .. Further, when the first and second alignment film-attached substrates obtained above are arranged so that the orientation processing directions are parallel to each other and opposite to each other (anti-parallel), an ECB type liquid crystal display element can be obtained.

Hereinafter, each of the steps [I] to [III] and [IV] included in the production method of the present invention will be described.
<Step [I]>
In step [I], (A) a photosensitive side-chain polymer that exhibits liquid crystallinity in a predetermined temperature range, (B) a reactive mesogen compound, and an organic solvent are placed on a substrate having an electrode for driving a liquid crystal display. The polymer composition contained therein is applied to form a coating film.

<Board>
The substrate is not particularly limited, but when the liquid crystal display element to be manufactured is a transmissive type, it is preferable to use a highly transparent substrate. In that case, the present invention is not particularly limited, and a glass substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate, or the like can be used.
As the electrode for driving the liquid crystal, ITO (Indium Tin Oxide: indium tin oxide), IZO (Indium Zinc Oxide: indium zinc oxide) and the like are preferable. Further, in the reflective liquid crystal display element, an opaque object such as a silicon wafer can be used if only one side of the substrate is used, and in this case, a material that reflects light such as aluminum can also be used as the electrode.
As a method for forming an electrode on a substrate, a conventionally known method can be used.

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

After applying the polymer composition on the substrate having the electrode for driving the liquid crystal display, the temperature is 50 to 230 ° C., preferably 50 to 200 ° C. by a heating means such as a hot plate, a heat circulation type oven or an IR (infrared) type oven. The coating can be obtained by evaporating the solvent for 0.4 minutes to 60 minutes, preferably 0.5 minutes to 10 minutes. The drying temperature at this time is preferably lower than the liquid crystal phase expression temperature of the side chain polymer.
If the thickness of the coating film is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may decrease. Therefore, it is preferably 5 nm to 300 nm, more preferably 10 nm to 150 nm. Is.
It is also possible to provide a step of cooling the substrate on which the coating film is formed to room temperature after the step [I] and before the subsequent step [II].

<Step [II]>
In the step [II], the coating film obtained in the step [I] is irradiated with ultraviolet rays polarized from an oblique direction. When irradiating the film surface of the coating film with polarized ultraviolet rays, the substrate is irradiated with the polarized ultraviolet rays from a certain direction through the polarizing plate. 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 via a filter or the like depending on the type of the coating film to be used. Then, 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 irradiation amount is polarized ultraviolet rays that realize the maximum value of ΔA (hereinafter, also referred to as ΔAmax), which is the difference between the ultraviolet absorptance in the direction parallel to the polarization direction of the polarized ultraviolet rays and the ultraviolet absorptivity in the vertical direction in the coating film. The amount is preferably in the range of 1% to 70%, and more preferably in the range of 1% to 50%.

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

As a method of adjusting the irradiation direction to the above angle, there are a method of tilting the substrate itself and a method of tilting the light source, but tilting the light source itself is more preferable from the viewpoint of throughput.

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

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

The thickness of the coating film formed after heating is preferably 5 nm to 300 nm, more preferably 50 nm to 150 nm for the same reason described in the step [I].
By having the above steps, the production method of the present invention can realize highly efficient introduction of anisotropy into the coating film. Then, a substrate with a liquid crystal alignment film can be manufactured with high efficiency.

<Process [IV]>
In the [IV] step, the substrate obtained by the two [III] arranged so that the sides on which the liquid crystal alignment film of the substrate was formed face each other, the liquid crystal layer provided between the substrates, and the substrate and the liquid crystal layer. It is a liquid crystal display element provided with a liquid crystal cell provided between the above and having the liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention. As such a vertical electrolytic drive type liquid crystal display element of the present invention, a twisted nematic (TN: Twisted Nematic) method, a vertical alignment (VA: Vertical Alignment) method, an STN (Super-Twisted Nematic) type liquid crystal display element, and an ECB ( Examples thereof include an Electrically Controlled Birefringence) type liquid crystal display element and an OCB (Optically Compensated Bend).

To give an example of manufacturing a liquid crystal cell or a liquid crystal display element, the above-mentioned first and second substrates are prepared, a spacer is sprayed on the liquid crystal alignment film of one of the substrates, and the liquid crystal alignment film surface is on the inside. In this way, if you want to obtain a twist nematic element, the ultraviolet exposure directions are orthogonal to each other, and if you want to obtain another element, attach the other substrate and inject the liquid crystal under reduced pressure. Examples thereof include a method of sealing, a method of dropping a liquid crystal on the liquid crystal alignment film surface on which a spacer is sprayed, and then laminating a substrate to perform sealing. The diameter of the spacer 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.

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

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

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

Then, in the coating film used in the method of the present invention, the irradiation amount of the polarized ultraviolet rays on the coating film and the heating temperature in the heat treatment are optimized. Thereby, it is possible to realize highly efficient introduction of anisotropy into the coating film.

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 a photocrossing reaction, a photoisomerization reaction, or a photoFries rearrangement reaction in the coating film. Corresponds to the irradiation amount of polarized ultraviolet rays that optimizes the amount. As a result of irradiating the coating film used in the present invention with polarized ultraviolet rays, if the number of photosensitive groups in the side chain that undergoes a photocrossover reaction, a photoisomerization reaction, or a photoFries rearrangement reaction is small, the amount of photoreaction is not sufficient. .. In that case, even if it is heated after that, sufficient self-organization does not proceed. On the other hand, in the coating film used in the present invention, as a result of irradiating a structure having a photocrosslinkable group with polarized ultraviolet rays, if the photosensitive group of the side chain undergoing a crosslink reaction becomes excessive, a crosslink reaction occurs between the side chains. It will go too far. In that case, the resulting membrane may become rigid and hinder the progress of self-organization by subsequent heating. Further, in the coating film used in the present invention, as a result of irradiating a structure having a photo Fries rearrangement group with polarized ultraviolet rays, when the photosensitive group of the side chain that undergoes a photo Fries rearrangement reaction becomes excessive, the liquid crystal property of the coating film becomes high. Will drop too much. In that case, the liquid crystallinity of the obtained film is also lowered, which may hinder the progress of self-organization due to the subsequent heating. Furthermore, when polarized ultraviolet rays are applied to a structure having a photo-Fries rearrangement group, if the irradiation amount of the ultraviolet rays is too large, the side chain polymer is photodecomposed and the subsequent heating hinders the progress of self-assembly. May become.

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

In the coating film used in the method of the present invention, a photocrosslinking reaction, a photoisomerization reaction, or a photofleece rearrangement reaction of a photosensitive group in the side chain of a side chain type polymer film is performed by optimizing the irradiation amount of polarized ultraviolet rays. 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, the suitable amount of polarized ultraviolet rays can be determined based on the evaluation of the ultraviolet absorption of the coating film used in the present invention.

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

In the production method of the present invention, the irradiation amount of polarized ultraviolet rays on the coating film used in the present invention is preferably in the range of 1% to 70% of the amount of polarized ultraviolet rays that realize ΔAmax, and is preferably 1% to 70%. It is more preferably within the range of 50%. In the coating film used in the present invention, the irradiation amount of the polarized ultraviolet rays in the range of 1% to 50% of the amount of the polarized ultraviolet rays realizing ΔAmax is 0. It corresponds to the amount of polarized ultraviolet rays in which 1 mol% to 20 mol% is subjected to a photocrosslinking reaction.

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

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

As described above, the substrate for a vertical electrolytic drive type liquid crystal display element manufactured by the method of the present invention or the vertical electrolytic drive type liquid crystal display element having the substrate has excellent reliability and has a large screen. It can be suitably used for high-definition LCD TVs and the like.

Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited to these Examples.

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

<Liquid crystal compound>

MA1 was synthesized with reference to Macromolecules 2007, 40, 6355-6360.
PLC1 was purchased and used as a commercial product.
As PLC2, LC242 (BASF), which can be purchased commercially, was used.
PLC4 was synthesized by the synthetic method described in Patent Document (Japanese Patent Laid-Open No. 9-118717).
PLC5 is a novel compound which has not been published in the literature. PLC5 was synthesized using PLC4 and PLC5-1, the details of which will be described in "<Synthesis of compound PLC5>" below. PLC5-1 was synthesized by the synthetic method described in the literature (Liquid Crystals (2005), 32 (8), 1031-1044.).
As the PLC6, M6BC (manufactured by Midori Chemical Co., Ltd.), which can be purchased commercially, was used.

<Synthesis of compound PLC5>
In a 500 mL four-necked flask, compound PLC4 (20.00 g, 65.3 mmol), compound PLC5-1 (14.09 g, 71.8 mmol), EDC (15.02 g, 78.4 mmol), DMAP (0.80 g, 0.80 g, 6.53 mmol) and THF (200 g) were added, and the reaction was carried out at 23 ° C. The reaction was followed up by HPLC, and after confirming the completion of the reaction, the reaction solution was poured into distilled water (1.2 L), ethyl acetate (2 L) was added, and the aqueous layer was removed by a liquid separation operation. After washing the organic layer with distilled water (500 mL) three times, the organic layer was dried over magnesium sulfate. Then, the solvent was distilled off by filtration and an evaporator to obtain compound PLC5-2 as an oily compound. Subsequently, pyridinium p-toluenesulfonic acid (denoted as PPTS) (1.59 g, 6.3 mmol) and ethanol (100 g) were added to the obtained compound PLC5-2, and the mixture was heated and stirred at 60 ° C. The reaction was followed up by HPLC, and after confirming the completion of the reaction, the reaction solution was cooled in an ice bath, and the precipitated solid was filtered and washed with ethanol. The obtained solid was dried under reduced pressure to obtain 19.2 g (yield 69%) of compound PLC5.
¹ H-NMR (400MHz, CDCl3, δppm): 8.22-8.18 (2H, m), 8.17-8.14 (2H, m), 7.36-7.32 (2H, m), 7.00-6.96 (2H, m), 6.12- 6.11 (1H, m), 5.57-5.55 (1H, m), 4.20-4.16 (2H, m), 4.06 (2H, t), 1.96-1.95 (3H, m), 1.90-1.46 (8H, m).

The conditions for measuring the molecular weight of the resin are as follows.
Equipment: Room temperature gel permeation chromatography (GPC) equipment (SSC-7200) manufactured by Senshu Kagaku Co., Ltd.,
Column: Shodex column (KD-803, KD-805),
Column temperature: 50 ° C,
Eluent: N, N'-dimethylformamide (as an additive, lithium bromide-hydrate (LiBr · H ₂ O) 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) 30 mmol / L, Tetrahydrofuran (THF) is 10 ml / L),
Flow velocity: 1.0 ml / min,
Standard samples for preparing calibration curves: Tosoh's TSK standard polyethylene oxide (molecular weight of about 9,000,000, 150,000, 100,000, 30,000) and Polymer Laboratory's polyethylene glycol (molecular weight of about 12,000, 4). 000, 1,000).

<Organic solvent>
NMP: N-methyl-2-pyrrolidone BCS: butyl cellosolve

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

<Example 1 of methacrylate polymer synthesis>
MA1 (28.6 g, 50.0 mmol) was dissolved in NMP (163.7 g), degassed with a diaphragm pump for nitrogen substitution, and then AIBN (0.25 g, 1.5 mmol) was added to remove it again. Nitrogen substitution was performed. Then, the reaction was carried out at 60 ° C. for 24 hours to obtain a polymer solution of methacrylate. This polymer solution was added dropwise to diethyl ether (5000 ml) and the resulting precipitate was filtered. The precipitate was washed with diethyl ether and dried under reduced pressure in an oven at 40 ° C. to obtain a methacrylate polymer powder P1. The obtained methacrylate polymer had a number average molecular weight of 46,000 and a weight average molecular weight of 119,600.
NMP (114.0 g) was added to the obtained methacrylic polymer powder (A) (6.0 g), and the mixture was stirred and dissolved at room temperature for 5 hours. BCS (30.0 g) was added to this solution, and the mixture was stirred at room temperature for 5 hours to obtain a liquid crystal alignment agent B1.

<Example 1>
0.04 g (10% by mass with respect to the solid content) of the liquid crystal compound PLC1 obtained in Synthesis Example 1 was added to 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, and the mixture was stirred at room temperature for 3 hours. The liquid crystal alignment agent B2 was prepared.
When the obtained liquid crystal alignment agent B2 was stored in a freezer for 1 day and thawed, no precipitate was confirmed.

<Example 2>
To 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.10 g (25% by mass with respect to the solid content) of the liquid crystal compound PLC1 obtained in Synthesis Example 1 was added, and the mixture was stirred at room temperature for 3 hours. The liquid crystal alignment agent B3 was prepared.
When the obtained liquid crystal alignment agent B3 was stored in a freezer for 1 day and thawed, no precipitate was confirmed.

<Example 3>
To 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.10 g (25% by mass with respect to the solid content) of the liquid crystal compound PLC2 obtained in Synthesis Example 1 was added, and the mixture was stirred at room temperature for 3 hours. To dissolve the liquid crystal alignment agent B4.
When the obtained liquid crystal alignment agent B4 was stored in a freezer for 1 day and thawed, no precipitate was confirmed.

<Comparative Example 1>
To 10.0 g of the liquid crystal alignment agent D1 obtained in Synthesis Example 1, 0.10 g (25% by mass with respect to the solid content) of the liquid crystal compound PLC3 obtained in Synthesis Example 1 was added, and the mixture was stirred at room temperature for 3 hours. The liquid crystal alignment agent B5 was prepared.
When the obtained liquid crystal alignment agent B5 was stored in a freezer for 1 day and thawed, no precipitate was confirmed.

<Comparative Example 2>
To 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.10 g (25% by mass with respect to the solid content) of the liquid crystal compound PLC4 obtained in Synthesis Example 1 was added, and the mixture was stirred at room temperature for 3 hours. To dissolve the liquid crystal alignment agent B6.
When the obtained liquid crystal alignment agent B6 was stored in a freezer for 1 day and thawed, no precipitate was confirmed.

<Comparative Example 3>
To 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.10 g (25% by mass with respect to the solid content) of the liquid crystal compound PLC5 obtained in Synthesis Example 1 was added, and the mixture was stirred at room temperature for 3 hours. The liquid crystal alignment agent B7 was prepared.
When the obtained liquid crystal alignment agent B7 was stored in a freezer for 1 day and thawed, no precipitate was confirmed.

<Comparative Example 4>
To 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.10 g (25% by mass with respect to the solid content) of the liquid crystal compound PLC6 obtained in Synthesis Example 1 was added, and the mixture was stirred at room temperature for 3 hours. The liquid crystal alignment agent B8 was prepared.
When the obtained liquid crystal alignment agent B8 was stored in a freezer for 1 day and thawed, no precipitate was confirmed.

<Example 4>
[Making a liquid crystal cell]
Using the liquid crystal alignment agent B3 obtained in Example 1, a twisted nematic liquid crystal cell was produced by the procedure as shown below.
The liquid crystal alignment agent B3 obtained in Example 1 was spin-coated on the ITO surface of the ITO electrode substrate on which the ITO electrode pattern was formed, dried on a hot plate at 70 ° C. for 90 seconds, and then horizontally with respect to the substrate. A liquid crystal alignment film having a thickness of 100 nm was formed by irradiating 50 mJ / cm ² with polarized ultraviolet rays of 313 nm tilted at 40 ° and heating on a hot plate at 200 ° C. for 10 minutes. A 6 μm bead spacer was sprayed on the liquid crystal alignment film of one of the above two substrates, and then a sealant (solvent type thermosetting type epoxy resin) was printed on the bead spacer. Next, after bonding the two substrates so that the orientation direction was orthogonal to each other, the sealant was cured to prepare an empty cell. A liquid crystal MLC-2003 (C080) (trade name manufactured by Merck Group) was injected into this empty cell by a vacuum injection method to prepare a twisted nematic liquid crystal cell. The prepared liquid crystal cell was then placed in a hot air circulation oven at 120 ° C. for 1 hour to reorient the liquid crystal.

<Example 5>
A twisted nematic liquid crystal cell was produced in the same manner as in Example 4 except that the angle of the polarized ultraviolet rays was set to 30 °.

<Example 6>
A twisted nematic liquid crystal cell was produced in the same manner as in Example 4 except that the polarized ultraviolet irradiation angle was set to 45 °.

<Example 7>
A twist nematic liquid crystal cell was produced in the same manner as in Example 4 except that the liquid crystal alignment agent B4 was used instead of the liquid crystal alignment agent B3.

<Example 8>
A twist nematic liquid crystal cell was produced in the same manner as in Example 5 except that the liquid crystal alignment agent B4 was used instead of the liquid crystal alignment agent B3.

<Example 9>
A twist nematic liquid crystal cell was produced in the same manner as in Example 6 except that the liquid crystal alignment agent B4 was used instead of the liquid crystal alignment agent B3.

<Example 10>
A twist nematic liquid crystal cell was produced in the same manner as in Example 6 except that the liquid crystal alignment agent B2 was used instead of the liquid crystal alignment agent B3.

<Comparative Example 5>
A twist nematic liquid crystal cell was produced in the same manner as in Example 4 except that the liquid crystal alignment agent B1 was used instead of the liquid crystal alignment agent B3 of Example 4.

<Comparative Example 6>
A twist nematic liquid crystal cell was produced in the same manner as in Example 6 except that the liquid crystal alignment agent B1 was used instead of the liquid crystal alignment agent B3.

<Comparative Examples 7 to 10>
A twisted nematic liquid crystal cell was produced in the same manner as in Example 6 except that the liquid crystal alignment agents B5 to B8 were used instead of the liquid crystal alignment agents B3, respectively.

(Measurement of pre-tilt angle)
The pre-tilt angle (°) of the twisted nematic liquid crystal cell was measured by the Muller matrix method with “Axo Scan” manufactured by Axo Metalix.

The results are as shown in Table 1 below.

As shown in Table 1, in Examples 4 to 10 to which the reactive mesogen compound as the component (B) was added, the obtained liquid crystal alignment film showed a pretilt angle suitable for the twist nematic mode. On the other hand, in Comparative Examples 5 and 6 using the liquid crystal alignment agent to which the reactive mesogen compound which is the component (B) is not added, the pretilt angle is 50 ° to 58 °, which is not a suitable pretilt angle for the twist nematic mode. There wasn't. Further, in Comparative Examples 7 to 10, in which a compound other than the mesogen compound was added, the pretilt angle was 0 °.

As described above, in the embodiment according to the present invention, an arbitrary pretilt can be exhibited by irradiating the alignment film containing the liquid crystal compound with ultraviolet rays in an oblique direction. It is possible to provide a liquid crystal alignment film suitable for the twist nematic mode.

<Example 11>
After producing a liquid crystal cell in the same manner as in Example 6, UV was irradiated from the outside of the liquid crystal cell through a bandpass filter of 365 nm at 5 J / cm ² .
(Voltage retention rate (VHR) evaluation)
For the evaluation of VHR, a voltage of 5 V was applied to the obtained liquid crystal cell at a temperature of 60 ° C. for 60 μs, and the holding voltage of the liquid crystal cell was measured after 16.67 ms.

The results are shown in Table 2 below.

As shown in Table 2, when the liquid crystal compound is polymerized in the liquid crystal cell by irradiating with ultraviolet rays of 365 nm in Example 11 according to the present invention, the voltage retention rate is improved, so that the long-term reliability is excellent. It is possible to provide a liquid crystal display element.

Claims (11)

(A) It has a photosensitive side chain that exhibits liquidity in the temperature range of 100 ° C to 300 ° C and causes a cross-linking reaction, an isomerization reaction, or a photofreeze rearrangement in response to light in the wavelength range of 250 nm to 400 nm. A side-chain type polymer, the side-chain type polymer has a photoreactive group that becomes a photosensitive side chain and a liquid crystal group that can form a mesogen group at a side chain site in the side-chain type polymer. The side chain type polymer, which is a polymer obtained by polymerizing the monomer having
(B) A polymer composition containing a reactive mesogen compound represented by the following formula (I) and (C) an organic solvent:
P-Sp-X-MG-X-Sp-P (I)
[In formula (I),
P is a polymerizable group
Sp is a spacer group having 1 to 20 carbon atoms.
X is a group or single bond selected from -O-, -S-, -CO-, -COO-, -OCO-, -OCO-O-.
MG is a mesogen group or a mesogen supporting group represented by the following formula II:
-(A ¹ -Z ¹ ) _m -A ² -Z ² -A ^3- (II)
(In formula (II), A ¹ , A ² and A ³ are mutually independent 1,4-phenylene groups, and one or more CH groups present in this group are also due to N. It may be replaced, or it is a 1,4-cyclohexylene group, one CH ₂ group present in this group or two non-adjacent CH ₂ groups are also due to O and / or S. It may be substituted, or it may be a 1,4-cyclohexenylene group or a naphthalene-2,6-diyl group, all of which are unsubstituted or one or more halogens. It may be substituted with a cyano or nitro group, or with an alkyl group, an alkoxy group or an alkanoyl group having 1 to 7 carbon atoms, and one or more H atoms in these groups are represented by F or Cl. May be replaced,
Z ¹ and Z ² are independently -COO-, -OCO-, -CH ₂ CH _2- , -OCH _2- , -CH ₂ O-, -CH = CH-, -CH = CH-COO- , -OCO-CH = CH- or a single bond, and m is 0, 1 or 2)]. The polymer composition according to claim 1, wherein the component (A) has any one of the photosensitive side chains selected from the group consisting of the following formulas (1) to (6).

[In the formula, A, B, and D are independently single-bonded, -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 the hydrogen atom bonded to them may be replaced with a halogen group;
T is a single bond or an alkylene group having 1 to 12 carbon atoms, and the hydrogen atom bonded to them may be replaced with a halogen group;
Y ₁ represents a ring selected from a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring and an alicyclic hydrocarbon having 5 to 8 carbon atoms, or the same or selected from their substituents. It is a group consisting of 2 to 6 different rings bonded via a bonding group B, and the hydrogen atoms bonded to them are independently −COOR ₀ (in the formula, R ₀ is an alkyl having 1 to 5 carbon atoms. (Representing a 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 alkyloxy group having 1 to 5 carbon atoms. May be replaced with;
Y ₂ is a group selected from the group consisting of a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon having 5 to 8 carbon atoms, and a combination thereof. The hydrogen atoms bonded to are independently -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 of;
R represents an alkoxy group having ₁ to 6 carbon atoms or represents the same definition as Y1;
Cou represents a coumarin-6-yl group or a coumarin-7-yl group, and the hydrogen atoms bonded to them are independently -NO ₂ , -CN, -CH = C (CN) ₂ , -CH = CH-. It 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;
X is a single bond, -COO-, -OCO-, -N = N-, -CH = CH-, -C≡C-, -CH = CH-CO-O-, or -O-CO-CH = Representing CH-, when the number of Xs is 2, the Xs may be the same or different;
P and Q are independently selected from the group consisting of a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon having 5 to 8 carbon atoms, and a combination thereof. It is a group; however, when X is -CH = CH-CO-O-, -O-CO-CH = CH-, P or Q on the side to which -CH = CH- is bound is an aromatic ring;
l1 is 0 or 1;
l2 is an integer from 0 to 2;
When both l1 and l2 are 0, A also represents a single bond when T is a single bond;
When l1 is 1, B also represents a single bond when T is a single bond;
H and I are groups independently selected from a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and a combination thereof]. The component (A) has the following formulas (21) to (31) [in the formulas, A, B, R, q1 and q2 have the same definitions as above;
_Y3 is a group selected from the group consisting of monovalent benzene rings, naphthalene rings, biphenyl rings, furan rings, nitrogen-containing heterocycles, alicyclic hydrocarbons having 5 to 8 carbon atoms, and combinations thereof. Yes, the hydrogen atoms attached to them 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 contains a hydrogen atom, -NO ₂ , -CN, -CH = C (CN) ₂ , -CH = CH-CN, a halogen group, a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, and nitrogen. Represents a heterocycle, an alicyclic hydrocarbon having 5 to 8 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms;
l represents an integer of 1 to 12, m represents an integer of 0 to 2, but in equations (23) to (26), the sum of all m is 2 or more, and m1, m2, and m3 are. 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 heterocycle, and an alicyclic hydrocarbon having 5 to 8 carbon atoms. And represents an alkyl group or an alkyloxy group;
Z ₁₁ and Z ₁₂ represent a single bond, -CO-, -CH ₂ O-, -CH = N-, -CF _2- . ] The polymer composition according to claim 1 or 2, which has any one liquid crystal side chain selected from the group consisting of.

[I] A step of applying the composition according to any one of claims 1 to 3 onto a substrate having an electrode for driving a liquid crystal display to form a coating film;
[II] A step of irradiating the coating film obtained in [I] with ultraviolet rays polarized from an oblique direction; and [III] a step of heating the coating film obtained in [II].
A method for manufacturing a substrate having the liquid crystal alignment film, which obtains a liquid crystal alignment film to which the orientation control ability is imparted. A substrate having a liquid crystal alignment film produced by the method according to claim 4. A vertical electric field drive type liquid crystal display element having the substrate according to claim 5. A twist-nematic type liquid crystal display element or an OCB type liquid crystal display element having the substrate according to claim 5. A step of preparing the substrate (first substrate) according to claim 5;
A step of obtaining a second substrate by using the steps [I] to [III] according to claim 4; and [IV] so that the liquid crystal alignment films of the first and second substrates face each other via the liquid crystal. In addition, a step of arranging the first and second substrates facing each other to obtain a liquid crystal display element;
A method for manufacturing a liquid crystal display element, wherein a vertical electric field drive type liquid crystal display element is obtained. In the [IV] step, the liquid crystal display elements are arranged so that the liquid crystal alignment films of the first and second substrates face each other via the liquid crystal and the first and second substrates are arranged facing each other so that the orientation directions are orthogonal to each other. The method for manufacturing a twisted nematic liquid crystal display element according to claim 8, which is a step of obtaining the above. A vertical electric field drive type liquid crystal display element manufactured by the method according to claim 8. A twisted nematic liquid crystal display element manufactured by the method according to claim 9.