KR102756251B1 - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Abstract

The present invention relates to a polymer composition containing (A) a photosensitive side chain polymer exhibiting liquid crystallinity in a predetermined temperature range, (B) a reactive mesogenic compound, and (C) an organic solvent. According to the present invention, a liquid crystal alignment film having excellent burn-in characteristics, a polymer composition providing the same, and a transverse electric field-driven liquid crystal display device are provided.

Description

Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element

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. Furthermore, the present invention relates to a novel method for producing a liquid crystal display element having excellent tilt angle characteristics.

Liquid crystal display elements are known as lightweight, thin, and low-power display devices, and have recently been making remarkable progress, such as being used in large-screen television applications. Liquid crystal display elements are configured by sandwiching a liquid crystal layer between a pair of transparent substrates equipped with electrodes, for example. In addition, in liquid crystal display elements, an organic film made of an organic material is used as a liquid crystal alignment film so that the liquid crystal can be aligned in a desired state between the substrates.

That is, the liquid crystal alignment film, as a component of a liquid crystal display element, is formed on the surface of a substrate that holds the liquid crystal and which comes into contact with the liquid crystal, and plays a role of aligning the liquid crystal in a certain direction between the substrates. In addition to the role of aligning the liquid crystal in a certain direction, such as in a direction parallel to the substrate, the liquid crystal alignment film is sometimes required to have a role of controlling the pretilt angle of the liquid crystal. The ability to control the alignment of the liquid crystal in the liquid crystal alignment film (hereinafter referred to as alignment controllability) is imparted by performing an alignment treatment on the organic film that constitutes the liquid crystal alignment film.

As a method for alignment treatment of a liquid crystal alignment film to impart alignment controllability, a rubbing method has been known from the past. The rubbing method is a method in which the surface of an organic film such as polyvinyl alcohol, polyamide or polyimide on a substrate is rubbed (rubbed) in a certain direction with a cloth such as cotton, nylon or polyester, and the liquid crystal is aligned in the rubbing direction (rubbing direction). Since this rubbing method can easily realize a relatively stable alignment state of the liquid crystal, it has been used in the manufacturing process of conventional liquid crystal display elements. In addition, as the organic film used for the liquid crystal alignment film, a polyimide-based organic film that has 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, etc., sometimes causes problems such as generation of dust or static electricity. In addition, due to the recent high definition of liquid crystal display elements and the unevenness of electrodes on the corresponding substrate or switching active elements for driving the liquid crystal, it has been impossible to evenly rub the surface of the liquid crystal alignment film with a cloth, and there have been cases where it has been impossible to evenly orient the liquid crystal.

Therefore, as another alignment treatment method for liquid crystal alignment films that do not require rubbing, the photoalignment method is being actively studied.

There are several methods for photo-alignment, but anisotropy is formed within the organic film that constitutes the liquid crystal alignment film by linearly polarized or collimated light, and the liquid crystals are aligned according to that anisotropy.

As a major optical alignment method, a decomposition-type optical alignment method is known. For example, polarized ultraviolet light is irradiated on a polyimide film, and anisotropic decomposition occurs by utilizing the polarization direction dependence of the ultraviolet absorption of the molecular structure. Then, the liquid crystal is aligned by the polyimide that remains without being decomposed (see Patent Document 1).

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

As in the above examples, the alignment treatment method of the liquid crystal alignment film by the photo-alignment method does not require rubbing, so there is no concern about generation of dust or static electricity. In addition, alignment treatment can be performed even on a substrate of a liquid crystal display element having an uneven surface, so it is a method of alignment treatment of a liquid crystal alignment film that is suitable for an industrial production process. In addition, since the photo-alignment method can control the alignment direction by ultraviolet rays, it is possible to compensate for viewing angle dependency by forming multiple areas with different alignment directions in a pixel (alignment division).

Meanwhile, the liquid crystal alignment film also plays a role in providing a certain inclination angle (pretilt angle) to the liquid crystal, and providing a pretilt angle is an important task in the development of the liquid crystal alignment film (see Patent Documents 3 to 6).

Japanese Patent No. 3893659 Japanese Patent Publication No. 02-223916 Japanese Patent Publication No. 04-281427 Japanese Patent Publication No. 05-043687 Japanese Patent Publication 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 photo-alignment method has a great advantage over the rubbing method, which has been industrially used as an alignment treatment method for liquid crystal display elements, in that it does not require the rubbing process itself. In addition, compared to the rubbing method in which the alignment controllability becomes approximately constant by rubbing, the photo-alignment method can control the alignment controllability by changing the amount of polarized light irradiation. However, in the photo-alignment method, when trying to achieve the same level of alignment controllability as in the case of the rubbing method, there are cases in which stable alignment of the liquid crystal cannot be achieved, such as when a large amount of polarized light irradiation is required.

For example, in the decomposition type photoalignment method described in the above-mentioned patent document 1, it is necessary to irradiate the polyimide film with ultraviolet light from a high-pressure mercury lamp with an output of 500 W for 60 minutes, which requires long-term and large-amount ultraviolet irradiation. In addition, even in the case of a dimerization type or photoisomerization type photoalignment method, there are cases where a large amount of ultraviolet irradiation of several J/cm2 to several tens of J/cm2 is required. In addition, in the case of a photocrosslinking type or photoisomerization type photoalignment method, since the thermal stability or light stability of the alignment of the liquid crystal is inferior, there was a problem that alignment defects or display burn-in occurred when it was used as a liquid crystal display element.

Accordingly, in the photo-alignment method, high efficiency of alignment processing and realization of stable liquid crystal alignment are required, and a liquid crystal alignment film or liquid crystal alignment agent capable of providing high alignment controllability to the liquid crystal alignment film with high efficiency is required.

The present invention aims to provide a substrate having a liquid crystal alignment film for a liquid crystal display element, which is provided with high-efficiency alignment controllability and has excellent tilt angle characteristics, and a conventional electrostatically driven liquid crystal display element (e.g., a twisted nematic (TN) type liquid crystal display element, a vertical alignment (VA) type liquid crystal display element, a super-twisted nematic (STN) type liquid crystal display element, an electrically controlled birefringence (ECB) type liquid crystal display element, and an optically compensated bend (OCB) type liquid crystal display element) having the substrate.

In addition, an object of the present invention is to provide, in addition to the above objects, a conventional electrostatically driven type liquid crystal display (e.g., a twisted nematic type liquid crystal display, a VA type liquid crystal display, an STN type liquid crystal display, an ECB type liquid crystal display, and an OCB type liquid crystal display) having improved tilt angle characteristics and a liquid crystal alignment film for the device. In addition, a conventional electrostatically driven liquid crystal display is a type in which liquid crystal molecules are driven by applying an electric field in a direction perpendicular to a substrate surface.

The present inventors, as a result of conducting thorough examination to achieve the above-mentioned task, discovered the following invention.

＜1＞ (A) A polymer composition containing a photosensitive side chain polymer exhibiting liquid crystallinity in a predetermined temperature range, (B) a reactive mesogenic compound, and an organic solvent.

＜2＞ In the above ＜1＞, it is preferable that the reactive mesogenic compound, which is component (B), is a compound represented by the following formula (I).

P-Sp-X-MG-X-Sp-P (I)

[In formula (I),

P is a polymerization 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 mesogenic group or a mesogenic 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)

(In formula (II), A ¹ , A ² and A ³ are each independently a 1,4-phenylene group, and one or more CH groups present in this group may be further substituted by N, or a 1,4-cyclohexylene group, and one CH ₂ group or two non-adjacent CH ₂ groups present in this group may be further substituted by O and (or) S, or a 1,4-cyclohexenylene group or a naphthalene-2,6-diyl group, and all of these groups may be unsubstituted, or substituted by one or more halogen, cyano or nitro groups, or by an alkyl group, alkoxy group or alkanoyl group having 1 to 7 carbon atoms, and one or more H atoms in these groups may be substituted by F or Cl,

Z ¹ and Z ² are each independently -COO-, -OCO-, -CH ₂ CH ₂ -, -OCH ₂ -, -CH ₂ O-, -CH=CH-, -CC=, -CH=CH-COO-, -OCO-CH=CH- or a single bond, and further

m is 0, 1 or 2).

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

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

[Chemical Formula 1]

[In the formula, A, B, and D each independently represent a single bond, -O-, -CH ₂ -, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-;

S is an alkylene group having 1 to 12 carbon atoms, and the hydrogen atoms bonded thereto may be replaced by halogen groups;

T is a single bond or an alkylene group having 1 to 12 carbon atoms, and the hydrogen atoms bonded thereto may be substituted 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 a group formed by bonding 2 to 6 identical or different rings selected from these substituents via a bonding group B, and the hydrogen atoms bonded to them may each be independently substituted with -COOR ₀ (wherein R ₀ represents an alkyl group having 1 to 5 carbon atoms), -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;

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, and the hydrogen atoms bonded thereto may each be independently substituted with -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;

R represents an alkoxy group having 1 to 6 carbon atoms, or has the same definition as Y ₁ ;

X represents a single bond, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CH=CH-CO-O-, or -O-CO-CH=CH-, and when the number of X is 2, X may be the same or different;

Cou represents a coumarin-6-yl group or a coumarin-7-yl group, and the hydrogen atoms bonded thereto may each be independently substituted with -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;

q1 and q2, one is 1 and the other is 0;

q3 is 0 or 1 ;

P and Q are each independently 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; provided that when X is -CH=CH-CO-O-, -O-CO-CH=CH-, P or Q on the side to which -CH=CH- is bonded is an aromatic ring;

l1 is 0 or 1 ;

l2 is an integer from 0 to 2;

When 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 each independently a group 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 one of the above ＜1＞ to ＜4＞, it is preferable that component (A) additionally has any one type of liquid crystalline 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;

Y ₃ is a group selected from the group consisting of 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 combinations thereof, and the hydrogen atoms bonded thereto may each 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 represents 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, a nitrogen-containing 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 from 1 to 12, m represents an integer from 0 to 2, and in formulas (23) to (26), the sum of all m is 2 or more, and m1, m2, and m3 each independently represent an integer from 1 to 3;

R ₂ represents 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 an alkyl group, or an alkyloxy group;

Z ₁₁ , Z ₁₂ represent single bonds, -CO-, -CH ₂ O-, -CH=N-, -CF ₂ -.

[Chemical formula 2]

＜6＞ [I] A process of forming a film by applying the polymer composition described in any one of the above ＜1＞ to ＜5＞ onto a substrate having an electrode for driving a liquid crystal;

[II] A process of irradiating the film obtained in [I] with polarized ultraviolet rays from an oblique direction; and

[III] Process of heating the film obtained in [II];

A method for manufacturing a substrate having a liquid crystal alignment film, which obtains a liquid crystal alignment film for a conventional electrostatically driven liquid crystal display device, wherein the liquid crystal alignment film has alignment controllability.

＜7＞ A substrate having a liquid crystal alignment film for a conventional electrostatically driven liquid crystal display device manufactured by the manufacturing method described in the above ＜6＞.

＜8＞ A conventional electrostatically driven liquid crystal display device having the substrate of the above ＜7＞.

＜9＞ A twisted nematic type liquid crystal display device or an OCB type liquid crystal display device having the substrate of the above ＜7＞.

＜10＞ Process for preparing the substrate (first substrate) of the above ＜7＞;

A process for obtaining a second substrate by using the processes [I] to [III] of the above <6>; and

[IV] A process for obtaining a liquid crystal display element by arranging first and second substrates so that the liquid crystal alignment films of the first and second substrates face each other through the interposition of liquid crystals;

A method for manufacturing a liquid crystal display element, wherein a conventional drive type liquid crystal display element is obtained by having the liquid crystal display element.

＜11＞ [IV] A method for manufacturing a twisted nematic type liquid crystal display device, wherein the process is a process of obtaining a liquid crystal display device by arranging first and second substrates so that the liquid crystal alignment films of the first and second substrates face each other with the alignment directions being orthogonal to each other through the interposition of liquid crystals.

＜12＞ A conventional electrostatically driven liquid crystal display device manufactured by the above ＜10＞.

＜13＞ A twisted nematic type liquid crystal display device manufactured by the above ＜11＞.

According to the present invention, it is possible to provide a substrate having a liquid crystal alignment film imparted with high-efficiency alignment controllability and excellent tilt angle characteristics, and a conventional electrostatically driven liquid crystal display device (e.g., a twisted nematic liquid crystal display device, a VA type liquid crystal display device, an STN type liquid crystal display device, an ECB type liquid crystal display device, and an OCB type liquid crystal display device) having the substrate.

The conventional electrostatically driven liquid crystal display device manufactured by the method of the present invention is provided with high-efficiency alignment controllability, so that display characteristics are not deteriorated even when continuously driven for a long period of time.

As a result of conducting preliminary research, the inventor obtained the following findings and completed the present invention.

The polymer composition used in the manufacturing method of the present invention has a photosensitive side chain polymer capable of exhibiting liquid crystallinity (hereinafter also simply referred to as a side chain polymer), and a coating film obtained by using the polymer composition is a film having a photosensitive side chain polymer capable of exhibiting liquid crystallinity. This coating film is not subjected to a rubbing treatment, but is subjected to an alignment treatment by polarized light irradiation. Then, after the polarized light irradiation, a step of heating the side chain polymer film is performed, thereby becoming a coating film imparted with alignment controllability (hereinafter also referred to as a liquid crystal alignment film). At this time, the slight anisotropy exhibited by the polarized light irradiation becomes a driving force, and the liquid crystal side chain polymer itself efficiently reorients by self-organization. As a result, a highly efficient alignment treatment is realized as a liquid crystal alignment film, and a liquid crystal alignment film imparted with high alignment controllability can be obtained.

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

＜＜(A) Side chain polymer＞＞

(A) The component is a photosensitive side chain polymer that exhibits liquid crystallinity within a certain temperature range.

(A) It is preferable that the side chain polymer reacts with light in the wavelength range of 250 nm to 400 nm and also exhibits liquid crystal properties in the temperature range of 100°C to 300°C.

(A) It is preferable that the side chain type polymer have a photosensitive side chain that reacts to light in the wavelength range of 250 nm to 400 nm.

(A) Since the side chain type polymer exhibits liquid crystallinity in the temperature range of 100°C to 300°C, it is preferable to have a mesogenic group.

(A) The side chain polymer has a side chain having photosensitivity bonded to the main chain, and can cause a crosslinking reaction, an isomerization reaction, or a photofree rearrangement in response to light. The structure of the side chain having photosensitivity is not particularly limited, but a structure that causes a crosslinking reaction or a photofree rearrangement in response to light is preferable, and one that causes a crosslinking reaction is more preferable. In this case, even if exposed to external stress such as heat, the realized alignment controllability can be stably maintained for a long period of time. The structure of the photosensitive side chain 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 have a rigid mesogen component. In this case, when the side chain polymer is used as a liquid crystal alignment film, stable liquid crystal alignment can be obtained.

The structure of the polymer may be, for example, a structure having a main chain and a side chain bonded thereto, the side chain having a mesogenic component such as a biphenyl group, a terphenyl group, a phenylcyclohexyl group, a phenylbenzoate group, or an azobenzene group, and a photosensitive group bonded to the tip that is sensitive to light and undergoes a crosslinking reaction or an isomerization reaction, or a structure having a main chain and a side chain bonded thereto, the side chain being a mesogenic component and also having a phenylbenzoate group that undergoes a photofree rearrangement reaction.

A more specific example of the structure of a photosensitive side chain polymer capable of exhibiting liquid crystallinity is preferably a structure having a main chain composed of at least one radical polymerizable group selected from the group consisting of hydrocarbons, (meth)acrylates, itaconates, fumarates, maleates, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, norbornene, and siloxanes, and a photosensitive side chain composed of at least one of the following formulae (1) to (6).

[Chemical Formula 3]

In the formula, A, B, and D each independently represent a single bond, -O-, -CH ₂ -, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-;

S is an alkylene group having 1 to 12 carbon atoms, and the hydrogen atoms bonded thereto may be substituted with a halogen group;

T is a single bond or an alkylene group having 1 to 12 carbon atoms, and the hydrogen atoms bonded thereto may be substituted 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 a group formed by bonding 2 to 6 identical or different rings selected from these substituents via a bonding group B, and the hydrogen atoms bonded to them may each be independently substituted with -COOR ₀ (wherein R ₀ represents an alkyl group having 1 to 5 carbon atoms), -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;

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, and the hydrogen atoms bonded thereto may each be independently substituted with -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;

R represents an alkoxy group having 1 to 6 carbon atoms, or has the same definition as Y ₁ ;

X represents a single bond, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CH=CH-CO-O-, or -O-CO-CH=CH-, and when the number of X is 2, X may be the same or different;

Cou represents a coumarin-6-yl group or a coumarin-7-yl group, and the hydrogen atoms bonded thereto may each be independently substituted with -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;

q1 and q2, one is 1 and the other is 0;

q3 is 0 or 1 ;

P and Q are each independently 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; provided that when X is -CH=CH-CO-O-, -O-CO-CH=CH-, P or Q on the side to which -CH=CH- is bonded is an aromatic ring;

l1 is 0 or 1 ;

l2 is an integer from 0 to 2;

When 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 each independently a group selected from a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and combinations thereof.

It is preferable that the side chain be any one photosensitive side chain 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 definitions as above;

l represents an integer from 1 to 12;

m represents an integer from 0 to 2, and m1 and m2 represent integers from 1 to 3;

n represents an integer from 0 to 12 (when n = 0, B is single bonded).

[Chemical Formula 4]

It is preferable that the side chain be any one photosensitive side chain 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.

[Chemical Formula 5]

It is preferable that the side chain be a photosensitive side chain represented by the following formula (14) or (15).

In the equation, A, Y ₁ , X, l, m1 and m2 have the same definitions as above.

[Chemical formula 6]

It is preferable that the side chain be a photosensitive side chain represented by the following formula (16) or (17).

In the equation, A, X, l and m have the same definitions as above.

[Chemical formula 7]

In addition, it is preferable that the side chain be a photosensitive side chain represented by the following formula (18) or (19).

In the equation, A, B, Y ₁ , q1, q2, m1, and m2 have the same definitions as above.

R ₁ represents 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 alkyloxy group having 1 to 5 carbon atoms.

[Chemical formula 8]

It is preferable that the side chain be a photosensitive side chain represented by the following formula (20).

In the equation, A, Y ₁ , X, l and m have the same definitions as above.

[Chemical formula 9]

In addition, it is preferable that the (A) side chain type polymer have any one type of liquid crystalline 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;

Y ₃ is a group selected from the group consisting of 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 combinations thereof, and the hydrogen atoms bonded thereto may each 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 represents 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, a nitrogen-containing 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 from 1 to 12, m represents an integer from 0 to 2, and in formulas (23) to (26), the sum of all m is 2 or more, and m1, m2, and m3 each independently represent an integer from 1 to 3;

R ₂ represents 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 an alkyl group, or an alkyloxy group;

Z ₁₁ , Z ₁₂ represent single bonds, -CO-, -CH ₂ O-, -CH=N-, -CF ₂ -.

[Chemical Formula 10]

＜＜Method for producing a photosensitive side chain polymer＞＞

The photosensitive side chain type polymer capable of expressing the above liquid crystallinity can be obtained by polymerizing a photoreactive side chain monomer having the above photosensitive side chain and a liquid crystal side chain monomer.

[Photoreactive side chain monomer]

A photoreactive side chain monomer is a monomer that, when forming a polymer, can form a polymer having a photosensitive side chain at the side chain portion of the polymer.

As the photoreactive group possessed by the side chain, the following structures and derivatives thereof are preferable.

[Chemical Formula 11]

More specific examples of the photoreactive side chain monomer include a polymerizable group composed of at least one radical polymerizable group selected from the group consisting of hydrocarbons, (meth)acrylates, itaconates, fumarates, maleates, α-methylene-γ-butyrolactones, styrenes, vinyls, maleimides, norbornene, and siloxanes, and a photosensitive side chain composed of at least one of the formulae (1) to (6), preferably a photosensitive side chain composed of at least one of the formulae (7) to (10), a photosensitive side chain composed of at least one of the formulae (11) to (13), a photosensitive side chain represented by the formulae (14) or (15), a photosensitive side chain represented by the formulae (16) or (17), a photosensitive side chain represented by the formulae (18) or (19), a photosensitive side chain represented by the formulae (19), It is preferable that the structure have a photosensitive side chain represented by (20).

As such a photoreactive side chain monomer, it is preferable that it exhibits a dimerization reaction or an isomerization reaction when irradiated with polarized ultraviolet light. As such a monomer, for example, a monomer selected from the following formulae M1-1 to M1-22 can be exemplified.

[Chemical Formula 12]

[Chemical Formula 13]

[Chemical Formula 14]

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

[Chemical Formula 15]

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

[Liquid crystal side chain monomer]

A liquid crystalline side chain monomer is a monomer in which a polymer derived from the monomer exhibits liquid crystalline properties and the polymer can form a mesogenic group at the side chain portion.

As a mesogenic group possessed by a side chain, there are those that form a mesogenic structure by themselves, such as biphenyl or phenyl benzoate, and those that form a mesogenic structure by hydrogen bonding between side chains, such as benzoic acid. The following structure is preferable as a mesogenic group possessed by a side chain.

[Chemical Formula 16]

A more specific example of the liquid crystalline side chain monomer is preferably a structure having a polymerizable group composed of at least one radical polymerizable group selected from the group consisting of hydrocarbons, (meth)acrylates, itaconates, fumarates, maleates, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, norbornene, and siloxanes, and a side chain composed of at least one of the formulae (21) to (30).

As a specific example of such a liquid crystalline 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.

[Chemical Formula 17]

[Chemical Formula 18]

(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 and is a natural number from 2 to 9.)

(A) The side chain type polymer can be obtained by a copolymerization reaction of the photoreactive side chain monomer that exhibits liquid crystallinity described above. In addition, it can be obtained by a copolymerization of a photoreactive side chain monomer that does not exhibit liquid crystallinity and a liquid crystal side chain monomer, or a copolymerization of a photoreactive side chain monomer that exhibits liquid crystallinity and a liquid crystal side chain monomer. In addition, it can be copolymerized with other monomers within a range that does not inhibit the ability to exhibit liquid crystallinity.

Other monomers include, for example, industrially available radical polymerizable monomers.

Specific examples of other monomers include unsaturated carboxylic acids, acrylic acid ester compounds, methacrylic acid ester compounds, maleimide compounds, acrylonitrile, maleic anhydride, styrene compounds, and vinyl compounds.

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

Examples of the acrylic acid ester compounds include methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthylacrylate, anthryl acrylate, anthryl methyl acrylate, phenyl acrylate, 2,2,2-trifluoroethyl acrylate, tert-butylacrylate, cyclohexylacrylate, isobornylacrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, 3-methoxybutylacrylate, 2-methyl-2-adamantylacrylate, 2-propyl-2-adamantylacrylate, 8-methyl-8-tricyclodecylacrylate, and 8-ethyl-8-tricyclodecylacrylate. You can hear it.

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

Examples of vinyl compounds include vinyl ether, methyl vinyl ether, benzyl vinyl ether, 2-hydroxyethyl vinyl ether, phenyl vinyl ether, and propyl vinyl ether.

Examples of styrene compounds include styrene, methylstyrene, chlorostyrene, and bromostyrene.

Examples of maleimide compounds include maleimide, N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide.

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

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

The side chain polymer of the present invention may contain side chains other than the photoreactive side chain and the liquid crystalline side chain. The content thereof is the remainder when the total content of the photoreactive side chain and the liquid crystalline side chain does not reach 100%.

There is no particular limitation on the method for producing the side chain polymer of the present embodiment, and a general method used industrially can be used. Specifically, it can be produced by cationic polymerization, radical polymerization, or anionic polymerization using the vinyl group of a liquid crystal side chain monomer or a photoreactive side chain monomer. Among these, radical polymerization is particularly preferable from the viewpoint of ease of reaction control, etc.

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

A radical thermal polymerization initiator is a compound that generates radicals when heated above its 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.), hydroperoxides (hydrogen peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyketals (dibutylperoxy cyclohexane, etc.), alkyl peresters (peroxyneodecanoic acid-tert-butyl ester, peroxypivalic acid-tert-butyl ester, peroxy2-ethylcyclohexanoic acid-tert-amyl ester, etc.), persulfates (potassium persulfate, sodium persulfate, ammonium persulfate, etc.), and azo compounds. (azobisisobutyronitrile, 2,2'-di(2-hydroxyethyl)azobisisobutyronitrile, etc.) These radical thermal polymerization initiators may be used singly, or two or more types may be used in combination.

The radical photopolymerization initiator is not particularly limited as long as it is a compound that initiates radical polymerization by light irradiation. Examples of such radical photopolymerization initiators include benzophenone, Michler's ketone, 4,4'-bis(diethylamino)benzophenone, xanthone, thioxanthone, isopropylxanthone, 2,4-diethylthioxanthone, 2-ethylanthraquinone, acetophenone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-2-methyl-4'-isopropylpropiophenone, 1-hydroxycyclohexylphenyl ketone, isopropylbenzoin ether, isobutylbenzoin ether, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, camphor quinone, benzanthrone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-Benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,4-dimethylaminobenzoate ethyl, 4-dimethylaminobenzoate isoamyl, 4,4'-di(t-butylperoxycarbonyl)benzophenone, 3,4,4'-tri(t-butylperoxycarbonyl)benzophenone, 2,4,6-trimethylbenzoyldiphenylphosphineoxide, 2-(4'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(3',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-pentyloxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 4-[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'-bis(2-chlorophenyl)-4,4',5,5'-tetrakis(4-ethoxycarbonylphenyl)-1,2'-biimidazole, 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4-dibromophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4,6-trichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 3-(2-methyl-2-dimethylaminopropionyl)carbazole, 3,6-Bis(2-methyl-2-morpholinopropionyl)-9-n-dodecylcarbazole, 1-hydroxycyclohexylphenyl ketone, bis(5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium, 3,3',4,4'-tetra(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, Examples thereof include 4,4'-di(methoxycarbonyl)-3,3'-di(t-butylperoxycarbonyl)benzophenone, 2-(3-methyl-3H-benzothiazol-2-ylidene)-1-naphthalen-2-yl-ethanone, or 2-(3-methyl-1,3-benzothiazol-2(3H)-ylidene)-1-(2-benzoyl)ethanone. These compounds may be used alone or in combination of two or more.

Radical polymerization is not particularly limited, and emulsion polymerization, suspension polymerization, dispersion polymerization, precipitation polymerization, bulk polymerization, solution polymerization, etc. can be used.

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

N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethyl sulfoxide, γ-butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, 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, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, etc.

These organic solvents may be used alone or in combination. In addition, even if they are solvents that do not dissolve the polymer produced, they may be mixed with the organic solvents described above and used within a range in which the polymer produced is not precipitated.

In addition, since oxygen in the organic solvent inhibits the polymerization reaction in radical polymerization, it is desirable to use an organic solvent that has been degassed to the extent possible.

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

In the radical polymerization reaction described above, if the ratio of the radical polymerization initiator is high with respect to the monomer, the molecular weight of the obtained polymer decreases, and if it is low, the molecular weight of the obtained polymer increases. Therefore, the ratio of the radical initiator is preferably 0.1 mol% to 10 mol% with respect to the monomer to be polymerized. In addition, various monomer components, solvents, initiators, etc. may be added during polymerization.

[Recovery of polymer]

When recovering a polymer generated from a reaction solution of a photosensitive side chain polymer capable of exhibiting liquid crystallinity obtained by the above-described reaction, the reaction solution may be introduced into a poor solvent and the polymers may be precipitated. Poor solvents used for precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, water, etc. The polymer introduced into a poor solvent and precipitated can be recovered by filtration and then dried at room temperature or by heating under normal pressure or reduced pressure. In addition, if the operation of redissolving the precipitated and recovered polymer in an organic solvent and recovering it by reprecipitation is repeated 2 to 10 times, the amount of impurities in the polymer can be reduced. As a poor solvent at this time, examples thereof include alcohols, ketones, hydrocarbons, etc., and it is preferable to use three or more types of poor solvents selected from these, as this further increases the efficiency of purification.

The molecular weight of the (A) side chain polymer of the present invention is preferably 2,000 to 1,000,000, more preferably 5,000 to 100,000, as measured by the GPC (Gel Permeation Chromatography) method, taking into account the strength of the resulting coating film, the workability during coating film formation, and the uniformity of the coating film.

＜＜(B) RM (Reactive Mesogenic Compound)＞＞

In a preferred embodiment of the present invention, the reactive mesogenic compound used in 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 polymerization 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 mesogenic group or a mesogenic support 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 meal,

A ¹ , A ² and A ³ are each independently a 1,4-phenylene group, and one or more CH groups present in this group may be further substituted by N, or a 1,4-cyclohexylene group, and one CH ₂ group or two non-adjacent CH ₂ groups present in this group may be further substituted by O and (or) S, or a 1,4-cyclohexenylene group or a naphthalene-2,6-diyl group, and all of these groups may be unsubstituted, or substituted by one or more halogen, cyano or nitro groups, or by an alkyl group, alkoxy group or alkanoyl group having 1 to 7 carbon atoms, and one or more H atoms in these groups may be substituted by F or Cl,

Z ¹ and Z ² are each independently -COO-, -OCO-, -CH ₂ CH ₂ -, -OCH ₂ -, -CH ₂ O-, -CH=CH-, -CC=, -CH=CH-COO-, -OCO-CH=CH- or a single bond, and

m is 0, 1 or 2).

A polymerizable mixture containing at least two kinds of reactive mesogenic compounds, at least one of which is a compound represented by formula I, is particularly preferred.

Two- and three-cyclic mesogenic compounds are preferred.

Halogen is preferably F or Cl.

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

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

[Chemical Formula 19]

In these suitable groups, Z ¹ and Z ² have the meanings indicated for the above formula I. 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 selected from the following formulae are particularly preferred:

[Chemical formula 20]

[Chemical Formula 21]

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

In these fitting equations, the base:

[Chemical Formula 22]

is, very preferably,

[Chemical Formula 23]

, and also,

[Chemical Formula 24]

In these groups, L independently has one of the above meanings.

Among these suitable compounds, R present has one of the meanings indicated for P-(Sp) _n -.

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

[Chemical Formula 25]

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 for this purpose can be used. The spacer group Sp is preferably bonded to the polymerizable group P by an ester or ether group, or by a single bond. The spacer group Sp is preferably a linear or branched alkylene group having 1 to 20 carbon atoms, especially 1 to 12 carbon atoms, and further wherein one CH ₂ group or two or more non-adjacent CH ₂ groups present in this group may be substituted by -O-, -S-, -NH-, -N(CH ₃ )-, -CO-, -O-CO-, -S-CO-, -O-COO-, -CO-S-, -CO-O-, -CH (halogen)-, -CH(CN)-, -CH=CH- or -C≡C-.

Representative spacer groups include, 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 which o is an integer from 2 to 12, and r is an integer from 1 to 3.

Suitable spacer groups are, for example, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, deylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylene-thioethylene, ethylene-N-methyliminoethylene and 1-methylalkylene.

In formula I, two P, Sp and X may be the same or superior to each other.

Representative examples of polymerizable mesogenic compounds represented by Formula I are shown in the compound list below. However, this list is merely illustrative and does not limit the scope of the present invention.

[Chemical Formula 26]

[Chemical Formula 27]

In these compounds, x and y are each independently 1 to 12, M ¹ is a hydrogen atom or a methyl group, and L ¹ and L ² are each independently H, halogen or CN, or an alkyl group, alkoxy group or alkanoyl group having 1 to 7 carbon atoms.

These compounds are either 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 thereof 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-dimethylimidazolidinone, ethylamyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethylene carbonate, propylene carbonate, diglyme, Examples thereof include 4-hydroxy-4-methyl-2-pentanone, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, and tripropylene glycol methyl ether. These may be used alone or in combination.

＜Polymer composition＞

A polymer composition is applied to the side of the substrate where the electrode is formed.

The polymer composition used in the manufacturing method of the present invention contains (A) a photosensitive side chain polymer exhibiting liquid crystallinity in a predetermined temperature range, (B) a reactive mesogenic compound, and (C) an organic solvent.

[Preparation of polymer composition]

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

In the polymer composition of the present embodiment, the above-described resin component may be entirely a photosensitive side chain polymer capable of expressing the liquid crystal properties described above, but other polymers may be mixed in addition to them as long as the liquid crystal expression ability and the photosensitivity are not inhibited. At that time, the content of the other polymer in the resin component is 0.5 mass% to 80 mass%, preferably 1 mass% to 50 mass%.

Such other polymers include, for example, polymers made of poly(meth)acrylate, polyamic acid, polyimide, etc., and polymers that 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-mentioned (A) component, (B) component, and (C) organic solvent. Examples thereof include, but are not limited to, solvents or compounds that improve film thickness uniformity or surface smoothness when the polymer composition is applied, and compounds that improve adhesion between the liquid crystal alignment film and the substrate.

Specific examples of solvents (poor solvents) that improve the uniformity of film thickness or 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 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, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 1-hexanol, n-hexane, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, Examples of solvents having a low surface tension include 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionic acid, butyl 3-methoxypropionic acid, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy)propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, and isoamyl lactate.

These empty solvents may be used alone or in combination of multiple types. When using the solvents described above, the amount is preferably 5 to 80 mass% of the total solvent, more preferably 20 to 60 mass%, so as not to significantly reduce the solubility of the entire solvent included in the polymer composition.

Compounds that improve the uniformity of film thickness or surface smoothness include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants.

More specifically, examples thereof include EF-TOP (registered trademark) 301, EF303, EF352 (manufactured by Tochem Products, Inc.), MEGAPAC (registered trademark) F171, F173, R-30 (manufactured by DIC), FLUORAD FC430, FC431 (manufactured by Sumitomo 3M, Inc.), ASAHIGUARD (registered trademark) AG710 (manufactured by Asahi Glass Co., Ltd.), SURFRON (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by AGC Seimi Chemical Co., Ltd.). The usage ratio of these surfactants is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, per 100 parts by mass of the resin component contained in the polymer composition.

Specific examples of compounds that improve 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-ureidpropyltrimethoxysilane, 3-ureidpropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, Examples thereof include 9-trimethoxysilyl-3,6-diazanonylacetate, 9-triethoxysilyl-3,6-diazanonylacetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylene)-3-aminopropyltrimethoxysilane, N-bis(oxyethylene)-3-aminopropyltriethoxysilane, etc.

In addition, in order to improve the adhesion between the substrate and the liquid crystal alignment film, and to prevent the deterioration of electrical characteristics due to backlight when forming a liquid crystal display element, an additive such as a phenoplast-based or epoxy-based compound may be contained in the polymer composition. Specific phenoplast-based additives are shown below, but are not limited to this structure.

[Chemical Formula 28]

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

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

As an additive, a photosensitizer may also be used. Colorless photosensitizers and triplet photosensitizers are preferred.

Photosensitizers include aromatic nitro compounds, coumarins (7-diethylamino-4-methylcoumarin, 7-hydroxy4-methylcoumarin), ketocoumarins, carbonylbiscoumarins, aromatic 2-hydroxyketones, and amino-substituted aromatic 2-hydroxyketones (2-hydroxybenzophenone, mono- or di-p-(dimethylamino)-2-hydroxybenzophenone), acetophenones, anthraquinones, xanthones, thioxanthones, benzanthrones, thiazolines (2-benzoylmethylene-3-methyl-β-naphthothiazoline, 2-(β-naphthoylmethylene)-3-methylbenzothiazoline, 2-(α-naphthoylmethylene)-3-methylbenzothiazoline, 2-(4-biphenoylmethylene)-3-methylbenzothiazoline, 2-(β-Naphthoylmethylene)-3-methyl-β-naphthothiazoline, 2-(4-biphenoylmethylene)-3-methyl-β-naphthothiazoline, 2-(p-fluorobenzoylmethylene)-3-methyl-β-naphthothiazoline), oxazolines (2-benzoylmethylene-3-methyl-β-naphthooxazoline, 2-(β-naphthoylmethylene)-3-methylbenzooxazoline, 2-(α-naphthoylmethylene)-3-methylbenzooxazoline, 2-(4-biphenoylmethylene)-3-methylbenzooxazoline, 2-(β-naphthoylmethylene)-3-methyl-β-naphthooxazoline, 2-(4-biphenoylmethylene)-3-methyl-β-naphthooxazoline, 2-(p-fluorobenzoylmethylene)-3-methyl-β-naphthoxazoline), benzothiazoles, nitroanilines (m- or p-nitroaniline, 2,4,6-trinitroaniline) or nitroacenaphthene (5-nitroacenaphthene), (2-[(m-hydroxy-p-methoxy)styryl]benzothiazoles, benzoin alkyl ethers, N-alkylated phthalones, acetophenone ketals (2,2-dimethoxyphenylethanone), naphthalene, anthracenes (2-naphthalenemethanol, 2-naphthalenecarboxylic acid, 9-anthracenemethanol, and 9-anthracenecarboxylic acid), benzopyrans, azoindolizines, merocoumarins, etc.

Preferably, aromatic 2-hydroxyketones (benzophenone), coumarin, ketocoumarin, carbonylbiscoumarin, acetophenone, anthraquinone, xanthone, thioxanthone, and acetophenone ketal.

A method for manufacturing a substrate having a liquid crystal alignment film of the present invention,

[I] A process for forming a film by applying a polymer composition containing (A) a photosensitive side chain polymer exhibiting liquid crystallinity in a predetermined temperature range, (B) a reactive mesogenic compound, and an organic solvent, onto a substrate having an electrode for driving a liquid crystal;

[II] A process of irradiating polarized ultraviolet rays to the film obtained in [I]; and

[III] Process of heating the film obtained in [II];

has

By the above process, a liquid crystal alignment film for a conventional electrostatically driven liquid crystal display device (e.g., a twisted nematic liquid crystal display device, a vertical alignment liquid crystal display device, an STN liquid crystal display device, an ECB liquid crystal display device, and an OCB liquid crystal display device) endowed with alignment controllability can be obtained, and a substrate having the liquid crystal alignment film can be obtained.

In addition, by preparing a second substrate in addition to the obtained substrate (first substrate), a conventional electrostatically driven liquid crystal display device (e.g., a twisted nematic liquid crystal display device, a vertical alignment liquid crystal display device, an STN type liquid crystal display device, an ECB type liquid crystal display device, and an OCB type liquid crystal display device) can be obtained.

A second substrate can be obtained by using the above processes [I] to [III], thereby having a liquid crystal alignment film with alignment controllability.

The manufacturing method of the conventional liquid crystal display device is as follows:

[IV] A process for obtaining a liquid crystal display element by arranging the first and second substrates obtained above so that the liquid crystal alignment films of the first and second substrates face each other through a liquid crystal interposed therebetween;

. At that time, when the substrates on which the first and second alignment films obtained above are formed and the tilt angle is 10 to 50 degrees are arranged so that the rubbing directions (alignment of the liquid crystal) are parallel and in the same direction (parallel alignment), an OCB type liquid crystal display element is obtained. When the same method is performed using two substrates on which the alignment films having the tilt angle of 80 to 90 degrees are formed, a vertical alignment type liquid crystal display element is obtained. When the rubbing directions are arranged so that they are orthogonal to each other, that is, twisted by about 90 degrees, a twisted nematic type liquid crystal display element is obtained, and when the rubbing directions are arranged so that they are twisted by about 260 degrees, an STN type liquid crystal display element is obtained. In addition, when the substrates on which the first and second alignment films obtained above are formed are arranged so that the alignment treatment directions are parallel and in the opposite direction (antiparallel), an ECB type liquid crystal display element is obtained.

Hereinafter, each of steps [I] to [III] and [IV] of the manufacturing method of the present invention will be described.

＜Fair [I]＞

In process [I], a polymer composition containing (A) a photosensitive side chain polymer exhibiting liquid crystal properties in a predetermined temperature range, (B) a reactive mesogenic compound, and an organic solvent is applied onto a substrate having an electrode for driving a liquid crystal, thereby forming a film.

＜Substrate＞

There is no particular limitation on the substrate, but if the liquid crystal display element being manufactured is a transparent type, it is preferable to use a highly transparent substrate. In that case, there is no particular limitation, and a glass substrate, or a plastic substrate such as an acrylic substrate or a polycarbonate substrate, etc. can be used.

As electrodes for driving liquid crystals, ITO (Indium Tin Oxide) and IZO (Indium Zinc Oxide) are preferable. Also, in the case of a reflective liquid crystal display element, an opaque material such as a silicon wafer can be used as long as it is only on one side of the substrate, and in this case, a material that reflects light such as aluminum can be used as the electrode.

As a method for forming electrodes on a substrate, a conventionally known method can be used.

The method for applying the above-described polymer composition onto a substrate having an electrode for driving a liquid crystal is not particularly limited.

The coating method is generally industrially implemented by screen printing, offset printing, flexographic printing, or inkjet printing. Other coating methods include dip coating, roll coater coating, slit coater coating, spinner coating, or spray coating, and these may be used depending on the purpose.

After applying the polymer composition onto a substrate having an electrode for driving a liquid crystal, the coating film can be obtained by evaporating the solvent at 50 to 230°C, preferably 50 to 200°C, for 0.4 to 60 minutes, preferably 0.5 to 10 minutes, by a heating means such as a hot plate, a heat circulation oven or an IR (infrared) type oven. The drying temperature at this time is preferably lower than the liquid crystal phase development temperature of the side-chain type polymer.

The thickness of the film is preferably 5 nm to 300 nm, more preferably 10 nm to 150 nm, because if the film is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if the film is too thin, the reliability of the liquid crystal display element may be reduced.

Additionally, a process of cooling the substrate on which the film has been formed to room temperature after the [I] process and before the subsequent [II] process can be set.

＜Fair [II]＞

In process [II], the coating film obtained in process [I] is irradiated with polarized ultraviolet rays from an oblique direction. When irradiating the polarized ultraviolet rays to the film surface of the coating film, the polarized ultraviolet rays are irradiated from a certain direction with respect to the substrate through a polarizing plate. As the ultraviolet rays to be used, ultraviolet rays with a wavelength in the range of 100 nm to 400 nm can be used. Preferably, the optimal wavelength is selected through a filter or the like depending on the type of coating film to be used. And, for example, ultraviolet rays with a wavelength in the range of 290 nm to 400 nm can be selected and used so as to selectively induce a photocrosslinking reaction. As the ultraviolet rays, light radiated from a high-pressure mercury lamp, for example, can be used.

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

The irradiation direction of polarized ultraviolet rays is usually 1° to 89° with respect to the substrate, but is 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.

There are two ways to adjust the direction of the irradiation to the above angle: one is to incline the substrate itself, and the other is to incline the light source. However, in terms of throughput, incline-ing the light source itself is more desirable.

＜Fair [III]＞

In process [III], the film irradiated with polarized ultraviolet rays in process [II] is heated. By heating, orientation controllability can be imparted to the film.

Heating can be done using a heating means such as a hot plate, a heat circulation oven, or an IR (infrared) type oven. The heating temperature can be determined by considering the temperature at which the liquid crystal properties of the coating film used are developed.

The heating temperature is preferably within the temperature range of the temperature at which the side chain type polymer exhibits liquid crystal properties (hereinafter referred to as the liquid crystal expression temperature). In the case of a thin film surface such as a coating, the liquid crystal expression temperature on the surface of the coating is expected to be lower than the liquid crystal expression temperature when the photosensitive side chain type polymer capable of exhibiting liquid crystal properties is observed in bulk. Therefore, the heating temperature is more preferably within the temperature range of the liquid crystal expression temperature on the surface of the coating. That is, the temperature range of the heating temperature after irradiation with polarized ultraviolet rays is preferably a temperature range in which the lower limit is 10°C lower than the lower limit of the temperature range of the liquid crystal expression temperature of the side chain type polymer used, and the upper limit is 10°C lower than the upper limit of the liquid crystal temperature range. If the heating temperature is lower than the above temperature range, the effect of amplifying the anisotropy due to heat in the coating tends to be insufficient, and if the heating temperature is excessively higher than the above temperature range, the state of the coating tends to approach an isotropic liquid state (isotropic phase), and in this case, it may become difficult to reorient in one direction by self-organization.

In addition, the liquid crystal development temperature refers to a temperature that is higher than the glass transition temperature (Tg) at which a side chain polymer or coating surface undergoes a phase transition from a solid phase to a liquid crystal phase, and lower than the isotropic phase transition temperature (Tiso) at which a phase transition occurs from a liquid crystal phase to an isotropic phase (isotropic phase).

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

By having the above process, the manufacturing method of the present invention can realize the introduction of anisotropy into the coating film with high efficiency. And, a substrate on which a liquid crystal alignment film is formed with high efficiency can be manufactured.

＜Fair [IV]＞

[IV] The process is a liquid crystal display device comprising two substrates obtained in [III] arranged so that the sides of the substrates on which the liquid crystal alignment films are formed face each other, a liquid crystal layer formed between the substrates, and a liquid crystal cell having the liquid crystal alignment film formed between the substrates and the liquid crystal layer and formed by the liquid crystal alignment agent of the present invention. Examples of the conventional electrolytically driven liquid crystal display device of the present invention include various types, such as a twisted nematic (TN: Twisted Nematic) type, a vertical alignment (VA: Vertical Alignment) type, a STN (Super-Twisted Nematic) type liquid crystal display device, an ECB (Electrically Controlled Birefringence) type liquid crystal display device, and an OCB (Optically Compensated Bend) type liquid crystal display device.

As an example of the production of a liquid crystal cell or a liquid crystal display element, the first and second substrates described above are prepared, spacers are dispersed on the liquid crystal alignment film of one substrate, the liquid crystal alignment film surface is turned inside, and if a twisted nematic type element is to be obtained, the ultraviolet exposure directions are orthogonal to each other, and if another element is to be obtained, different substrates are bonded as described above, and a liquid crystal is injected under reduced pressure and sealed, or a liquid crystal is dropped on the liquid crystal alignment film surface on which the spacers are dispersed, and then the substrates are bonded and sealed. 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 a pair of substrates that sandwich the liquid crystal layer, i.e., the thickness of the liquid crystal layer.

It is also preferable to perform annealing treatment on the obtained liquid crystal display element for orientation stability. The heating temperature is preferably 10 to 160°C, more preferably 50 to 140°C, which is the phase transition temperature of the liquid crystal.

The method for manufacturing a substrate having a film formed thereon according to the present invention comprises: applying a polymer composition onto a substrate to form a film, and then irradiating the substrate with polarized ultraviolet rays; then, by heating, highly efficient anisotropy introduction into the side chain type polymer film is realized, thereby manufacturing a substrate having a liquid crystal alignment film having the ability to control the alignment of liquid crystals formed thereon.

In the coating film used in the present invention, high-efficiency anisotropy introduction to the coating film is realized by utilizing the principle of molecular reorientation caused by self-organization based on the photoreaction and liquid crystallinity of the side chain. In the manufacturing method of the present invention, when the side chain type polymer has a structure having a photocrosslinkable group as a photoreactive group, a coating film is formed on a substrate using the side chain type polymer, and then polarized ultraviolet rays are irradiated, and then heating is performed, and a liquid crystal display element is manufactured.

Therefore, the coating film used in the method of the present invention can be a liquid crystal alignment film in which anisotropy is introduced with high efficiency and excellent alignment controllability by sequentially performing polarized ultraviolet ray irradiation and heat treatment on the coating film.

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

The optimal amount of polarized ultraviolet ray for highly efficient anisotropy introduction into the coating used in the present invention corresponds to the amount of polarized ultraviolet ray that optimizes the amount of photosensitive groups in the coating that undergo photocrosslinking reaction, photoisomerization reaction, or photofree rearrangement reaction. When the coating used in the present invention is irradiated with polarized ultraviolet ray, if the number of photosensitive groups in the side chains that undergo photocrosslinking reaction, photoisomerization reaction, or photofree rearrangement reaction is small, the amount of photoreaction is not sufficient. In that case, sufficient self-organization does not proceed even if it is heated thereafter. On the other hand, when the coating used in the present invention is irradiated with polarized ultraviolet ray to a structure having a photocrosslinkable group, if the number of photosensitive groups in the side chains that undergo crosslinking reaction is excessive, the crosslinking reaction between the side chains proceeds excessively. In that case, the obtained film becomes rigid, and the progress of self-organization by subsequent heating may be hindered. In addition, when polarized ultraviolet rays are irradiated on the structure having the optical free potential in the coating film used in the present invention, if the photosensitive group of the side chain that reacts with the optical free potential is excessive, the liquid crystallinity of the coating film is excessively reduced. In that case, the liquid crystallinity of the obtained film is also reduced, and there are cases where the progress of self-organization by subsequent heating is hindered. In addition, when irradiating polarized ultraviolet rays on the structure having the optical free potential, if the amount of ultraviolet rays is too large, the side chain-type polymer may be photodecomposed, and there are cases where the progress of self-organization by subsequent heating is hindered.

Therefore, in the coating film used in the present invention, the optimal amount of the photosensitive group of the side chain that undergoes a photocrosslinking reaction, photoisomerization reaction, or photofree rearrangement reaction by irradiation with polarized ultraviolet light is preferably 0.1 mol% to 40 mol% of the photosensitive group of the side chain type polymer film, more preferably 0.1 mol% to 20 mol%. By setting the amount of the photosensitive group of the side chain that undergoes a photoreaction within this range, self-organization in the subsequent heat treatment proceeds efficiently, and highly efficient anisotropic formation in the film becomes possible.

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

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

In the manufacturing method of the present invention, the amount of polarized ultraviolet ray irradiated to the coating film used in the present invention is preferably within the range of 1% to 70% of the amount of polarized ultraviolet ray that realizes ΔAmax, and more preferably within the range of 1% to 50%. In the coating film used in the present invention, the amount of polarized ultraviolet ray irradiated within the range of 1% to 50% of the amount of polarized ultraviolet ray that realizes ΔAmax corresponds to the amount of polarized ultraviolet ray that causes 0.1 mol% to 20 mol% of the total photosensitive groups possessed by the side-chain type polymer film to undergo a photocrosslinking reaction.

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

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

As described above, the substrate for a conventional electrostatically driven liquid crystal display device manufactured by the method of the present invention or the conventional electrostatically driven liquid crystal display device having the substrate has excellent reliability and can be suitably used in large-screen, high-definition liquid crystal televisions and the like.

Hereinafter, the present invention will be described using examples, but the present invention is not limited to the examples.

Example

The abbreviations used in the examples are as follows.

＜Methacryl Monomer＞

[Chemical formula 29]

<Liquid crystal compound>

[Chemical formula 30]

MA1 was synthesized with reference to Macromolecules 2007, 40, 6355-6360.

PLC1 was purchased and used as a commercial product.

PLC2 used commercially available LC242 (BASF).

PLC4 was synthesized using the synthetic method described in the patent document (Japanese Patent Application Laid-Open No. 9-118717).

PLC5 is a novel compound that has not been published in the literature, etc. PLC5 was synthesized using PLC4 and PLC5-1, and the details are explained in “<Synthesis of Compound PLC5>” below. In addition, PLC5-1 was synthesized using the synthetic method described in the literature (Liquid Crystals (2005), 32 (8), 1031-1044.).

PLC6 used commercially available M6BC (manufactured by Midori Chemical Co., Ltd.).

＜Synthesis of compound PLC5＞

In a 500 mL 4-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, 6.53 mmol), and THF (200 g) were added, and the reaction was performed at 23°C. The reaction was monitored 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 separation. The organic layer was washed three times with distilled water (500 mL), and then dried over magnesium sulfate. Thereafter, compound PLC5-2 was obtained as an oily compound by filtration and distillation of the solvent using an evaporator. Continued, pyridinium p-toluenesulfonic acid (represented 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 monitored 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.

[Chemical Formula 31]

Also, the conditions for measuring the molecular weight of the resin are as follows.

Device: Senshu Science Co., Ltd. manufactured room temperature gel permeation chromatography (GPC) device (SSC-7200),

Column: Column manufactured by Shodex (KD-803, KD-805),

Column temperature: 50 ℃,

Eluent: N,N'-dimethylformamide (as additives, lithium bromide hydrate (LiBr H ₂ O) 30 mmol/L, phosphoric acid anhydrous crystal (o-phosphoric acid) 30 mmol/L, tetrahydrofuran (THF) 10 ml/L),

Flow rate: 1.0 ml/min,

Standard samples for preparing calibration curves: TSK standard polyethylene oxide manufactured by Tosoh Corporation (molecular weights: approximately 9,000,000, 150,000, 100,000, 30,000), and polyethylene glycol manufactured by Polymer Laboratories (molecular weights: approximately 12,000, 4,000, 1,000).

＜Organic solvent＞

NMP: N-Methyl-2-pyrrolidone

BCS: Butyl Cellosolve

＜Polymerization initiator＞

AIBN: 2,2'-Azobisisobutyronitrile

＜Methacrylate polymer synthesis example 1＞

MA1 (28.6 g, 50.0 mmol) was dissolved in NMP (163.7 g), degassed with a diaphragm pump, and nitrogen replacement was performed, then AIBN (0.25 g, 1.5 mmol) was added, degassed again, and nitrogen replacement was performed. After this, the reaction was performed at 60°C for 24 hours, to obtain a methacrylate polymer solution. This polymer solution was added dropwise to diethyl ether (5000 ml), and the obtained precipitate was filtered. The precipitate was washed with diethyl ether and dried under reduced pressure in an oven at 40°C to obtain methacrylate polymer powder P1. The number average molecular weight of the obtained methacrylate polymer was 46,000, and the weight average molecular weight was 119,600.

NMP (114.0 g) was added to the obtained methacrylic polymer powder (A) (6.0 g), and stirred at room temperature for 5 hours to dissolve. BCS (30.0 g) was added to this solution, and stirred at room temperature for 5 hours to obtain a liquid crystal alignment agent B1.

＜Example 1＞

To 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.04 g (10 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 to dissolve, thereby preparing the liquid crystal alignment agent B2.

The obtained liquid crystal alignment agent B2 was stored in the freezer for one day and thawed, and no precipitate was observed.

＜Example 2＞

To 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.10 g (25 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 to dissolve, thereby preparing a liquid crystal alignment agent B3.

The obtained liquid crystal alignment agent B3 was stored in a freezer for one day and thawed, and no precipitate was observed.

＜Example 3＞

To 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.10 g (25 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, thereby preparing the liquid crystal alignment agent B4.

The obtained liquid crystal alignment agent B4 was stored in the freezer for one day and thawed, and no precipitate was observed.

＜Comparative Example 1＞

To 10.0 g of the liquid crystal alignment agent D1 obtained in Synthesis Example 1, 0.10 g (25 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 to dissolve, thereby preparing a liquid crystal alignment agent B5.

The obtained liquid crystal alignment agent B5 was stored in the freezer for one day and thawed, but no precipitate was observed.

＜Comparative Example 2＞

To 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.10 g (25 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, thereby preparing the liquid crystal alignment agent B6.

The obtained liquid crystal alignment agent B6 was stored in the freezer for one day and thawed, but no precipitate was observed.

＜Comparative Example 3＞

To 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.10 g (25 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 to dissolve, thereby preparing a liquid crystal alignment agent B7.

The obtained liquid crystal alignment agent B7 was stored in the freezer for one day and thawed, and no precipitate was observed.

＜Comparative Example 4＞

To 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.10 g (25 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 to dissolve, thereby preparing the liquid crystal alignment agent B8.

The obtained liquid crystal alignment agent B8 was stored in the freezer for one day and thawed, and no precipitate was observed.

<Example 4>

[Production of liquid crystal cells]

A twisted nematic liquid crystal cell was produced using the liquid crystal alignment agent B3 obtained in Example 1 in the following order.

The liquid crystal alignment agent B3 obtained in Example 1 was spin-coated on the ITO surface of an ITO electrode substrate having an ITO electrode pattern formed thereon, and dried on a 70°C hot plate for 90 seconds, then irradiated with 50 mJ/cm2 of polarized ultraviolet light of 313 nm inclined at 40° from the horizontal direction with respect to the substrate, and heated on a 200°C hot plate for 10 minutes to form a liquid crystal alignment film having a film thickness of 100 nm. A 6 μm bead spacer was spread on the liquid crystal alignment film of one of the two substrates, and then a sealant (solvent-based heat-curing type epoxy resin) was printed thereon. Then, the two substrates were bonded together so that the alignment direction was orthogonal, and the sealant was cured to produce an empty cell. A twisted nematic liquid crystal cell was produced by injecting liquid crystal MLC-2003 (C080) (Merck product name) into this empty cell by the reduced pressure injection method. The produced liquid crystal cell was then placed in a hot air circulation oven at 120°C for 1 hour to perform liquid crystal reorientation treatment.

＜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 ray 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 polarizing ultraviolet irradiation angle was set to 45°.

＜Example 7＞

A twisted nematic liquid crystal cell was fabricated in the same manner as in Example 4, except that liquid crystal alignment agent B4 was used instead of liquid crystal alignment agent B3.

＜Example 8＞

A twisted nematic liquid crystal cell was fabricated in the same manner as in Example 5, except that liquid crystal alignment agent B4 was used instead of liquid crystal alignment agent B3.

＜Example 9＞

A twisted nematic liquid crystal cell was fabricated in the same manner as in Example 6, except that liquid crystal alignment agent B4 was used instead of liquid crystal alignment agent B3.

＜Example 10＞

A twisted nematic liquid crystal cell was fabricated in the same manner as in Example 6, except that liquid crystal alignment agent B2 was used instead of liquid crystal alignment agent B3.

<Comparative Example 5>

A twisted nematic liquid crystal cell was produced in the same manner as in Example 4, except that liquid crystal alignment agent B1 was used instead of liquid crystal alignment agent B3 of Example 4.

<Comparative Example 6>

A twisted nematic liquid crystal cell was fabricated in the same manner as in Example 6, except that liquid crystal alignment agent B1 was used instead of 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 liquid crystal alignment agents B5 to B8 were used instead of liquid crystal alignment agent B3, respectively.

(Measurement of pretilt angle)

The pretilt angle (°) of the twisted nematic liquid crystal cell was measured using the Mueller matrix method with “Axo Scan” manufactured by Axo Metrix.

The results were as shown in Table 1 below.

As shown in Table 1, in Examples 4 to 10 in which the reactive mesogenic compound (B) as the component was added, the obtained liquid crystal alignment films exhibited a pretilt angle desirable for the twisted nematic mode. On the other hand, in Comparative Examples 5 and 6 in which a liquid crystal alignment agent to which the reactive mesogenic compound (B) as the component was not added was used, the pretilt angle was 50° to 58°, which was not a pretilt angle desirable for the twisted nematic mode. In addition, in Comparative Examples 7 to 10 in which a compound other than a mesogenic compound was added, the pretilt angle was 0°.

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

＜Example 11＞

After producing a liquid crystal cell in the same manner as in Example 6, UV light passing through a 365 nm band pass filter was irradiated at 5 J/cm2 from the outside of the liquid crystal cell.

(Voltage Hold Rate (VHR) Evaluation)

To evaluate the VHR, a voltage of 5 V was applied to the obtained liquid crystal cell for 60 μs at a temperature of 60 °C, and the holding voltage of the liquid crystal cell was measured after 16.67 ms.

The results were as shown in Table 2 below.

As shown in Table 2, by irradiating the liquid crystal compound with ultraviolet rays of 365 nm in Example 11 accompanying the present invention, the voltage retention rate is improved by polymerizing the liquid crystal compound within the liquid crystal cell, thereby making it possible to provide a liquid crystal display element having excellent long-term reliability.

Claims (13)

(A) A photosensitive side chain polymer that exhibits liquid crystallinity within a given temperature range.
(B) a reactive mesogenic compound, and
(C) Organic solvent
As a polymer composition containing,
(A) A polymer composition, wherein the component has one photosensitive side chain selected from the group consisting of the following formulas (1) to (6).
[Chemical Formula 1]

[In the formula, A, B, and D each independently represent a single bond, -O-, -CH ₂ -, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-;
S is an alkylene group having 1 to 12 carbon atoms, and the hydrogen atoms bonded thereto may be replaced by a halogen group;
T is a single bond or an alkylene group having 1 to 12 carbon atoms, and the hydrogen atoms bonded thereto may be substituted 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 a group formed by bonding 2 to 6 identical or different rings selected from these substituents via a bonding group B, and the hydrogen atoms bonded to them may each be independently substituted with -COOR ₀ (wherein R ₀ represents an alkyl group having 1 to 5 carbon atoms), -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;
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, and the hydrogen atoms bonded thereto may each be independently substituted with -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;
R represents an alkoxy group having 1 to 6 carbon atoms, or has the same definition as Y ₁ ;
Cou represents a coumarin-6-yl group or a coumarin-7-yl group, and the hydrogen atoms bonded thereto may each be independently substituted with -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;
q1 and q2, one is 1 and the other is 0;
q3 is 0 or 1 ;
X represents a single bond, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CH=CH-CO-O-, or -O-CO-CH=CH-, and when the number of X is 2, X may be the same or different;
P and Q are each independently 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; provided that when X is -CH=CH-CO-O-, -O-CO-CH=CH-, P or Q on the side to which -CH=CH- is bonded is an aromatic ring;
l1 is 0 or 1 ;
l2 is an integer from 0 to 2;
When 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 each independently a group selected from a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and combinations thereof. In paragraph 1,
(B) A polymer composition, wherein the reactive mesogenic compound as a component is a compound represented by the following formula (I).
P-Sp-X-MG-X-Sp-P (I)
[In formula (I),
P is a polymerization 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 mesogenic group or a mesogenic support group, and is selected according to 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 each independently a 1,4-phenylene group, and one or more CH groups present in this group may be further substituted by N, or a 1,4-cyclohexylene group, and one CH ₂ group or two non-adjacent CH ₂ groups present in this group may be further substituted by O and (or) S, or a 1,4-cyclohexenylene group or a naphthalene-2,6-diyl group, and all of these groups may be unsubstituted, or substituted by one or more halogen, cyano or nitro groups, or by an alkyl group, alkoxy group or alkanoyl group having 1 to 7 carbon atoms, and one or more H atoms in these groups may be substituted by F or Cl,
Z ¹ and Z ² are each independently -COO-, -OCO-, -CH ₂ CH ₂ -, -OCH ₂ -, -CH ₂ O-, -CH=CH-, -CC=, -CH=CH-COO-, -OCO-CH=CH- or a single bond, and further
m is 0, 1 or 2). In paragraph 1,
(A) A polymer composition, wherein the component has a photosensitive side chain that causes photocrosslinking, photoisomerization, or photofree transition. In paragraph 1,
(A) Components are formulas (21) to (31) below [wherein A and B have the same definitions as above;
In the formula, A, B, R, q1 and q2 have the same definitions as above;
Y ₃ is a group selected from the group consisting of 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 combinations thereof, and the hydrogen atoms bonded thereto may each 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 represents 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, a nitrogen-containing 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 from 1 to 12, m represents an integer from 0 to 2, and in formulas (23) to (26), the sum of all m is 2 or more, and m1, m2, and m3 each independently represent an integer from 1 to 3;
R ₂ represents 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 an alkyl group, or an alkyloxy group;
A polymer composition having any one type of liquid crystalline side chain selected from the group consisting of [Z ₁₁ , Z ₁₂ represent a single bond, -CO-, -CH ₂ O-, -CH=N-, -CF ₂ -].
[Chemical formula 2]
[I] A process of forming a film by applying the composition described in any one of claims 1 to 4 onto a substrate having an electrode for driving a liquid crystal;
[II] A process of irradiating the film obtained in [I] with polarized ultraviolet rays from an oblique direction; and
[III] Process of heating the film obtained in [II];
A method for manufacturing a substrate having a liquid crystal alignment film, wherein the liquid crystal alignment film is provided with alignment controllability by having the liquid crystal alignment film. A substrate having a liquid crystal alignment film manufactured by the method described in claim 5. A conventional electrostatically driven liquid crystal display device having a substrate as described in claim 6. A twisted nematic liquid crystal display device having a substrate as described in claim 6. An OCB type liquid crystal display device having a substrate as described in claim 6. A process for preparing a substrate (first substrate) having a liquid crystal alignment film manufactured by the method described in Article 5;
A process for obtaining a second substrate by using the processes [I] to [III] described in Article 5; and
[IV] A process for obtaining a liquid crystal display element by arranging first and second substrates so that the liquid crystal alignment films of the first and second substrates face each other through the interposition of liquid crystals;
A method for manufacturing a liquid crystal display element, wherein a conventional drive type liquid crystal display element is obtained by having the liquid crystal display element. In Article 10,
A method for manufacturing a twisted nematic type liquid crystal display device,
[IV] A manufacturing method, wherein the process is a process of obtaining a liquid crystal display element by arranging first and second substrates so that the liquid crystal alignment films of the first and second substrates face each other with the alignment directions being orthogonal to each other through the interposition of liquid crystals. A conventional electrochemically driven liquid crystal display device manufactured by the method described in Article 10. A twisted nematic type liquid crystal display device manufactured by the method described in claim 11.