TWI726987B - 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 type polymer that exhibits liquid crystallinity in a predetermined temperature range, (B) a reactive mesogen compound, and (C) an organic solvent. According to the present invention, there is provided a liquid crystal alignment film that imparts alignment control ability with high efficiency and is excellent in burn-in characteristics, a polymer composition imparted thereto, and a lateral electric field drive type liquid crystal display element.

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 manufacturing a substrate having the alignment film. It further relates to a novel method for manufacturing a liquid crystal display element with excellent tilt angle characteristics.

Liquid crystal display elements are known as light-weight, thin, and low-power-consumption display devices, and they have been used for large-scale television applications in recent years. The liquid crystal display element is configured by sandwiching a liquid crystal layer between a pair of transparent substrates provided with electrodes, for example. However, in a liquid crystal display element, an organic film composed of an organic material is used as a liquid crystal alignment film in such a manner that the liquid crystal is in a desired alignment state between the substrates.

That is, the liquid crystal alignment film is a constituent member of the liquid crystal display element, and is formed on the contact surface of the substrate holding the liquid crystal with the liquid crystal, and has the role of aligning the liquid crystal in a certain direction between the substrates. However, in the liquid crystal alignment film, in addition to the function of aligning the liquid crystal in a certain direction such as a parallel direction with respect to the substrate, there are cases where the function of controlling the pretilt angle of the liquid crystal is pursued. In such a liquid crystal alignment film, the ability to control the alignment of the liquid crystal (hereinafter referred to as the alignment The control ability) is imparted by the alignment treatment of the organic film constituting the liquid crystal alignment film.

The alignment treatment method of the liquid crystal alignment film for imparting alignment control ability is known from the conventional rubbing method. The rubbing method refers to the organic film of polyvinyl alcohol, polyamide, or polyimide on the substrate, and the surface is wiped (rubbed) in a certain direction with a cloth of cotton, nylon, polyester, etc., in the wiping direction (Rubbing direction) A method of aligning liquid crystals. Since this rubbing method can easily realize a relatively stable alignment state of liquid crystals, it has been used in the manufacturing process of conventional liquid crystal display elements. Regarding the organic film used for the liquid crystal alignment film, polyimide-based organic films that are excellent in reliability such as heat resistance and electrical properties are mainly selected.

However, the rubbing method of rubbing the surface of the liquid crystal alignment film composed of polyimide or the like has the problem of generating dust or static electricity. In addition, due to the high-definition of liquid crystal display elements in recent years or the unevenness caused by the electrodes on the substrate or the switching active element for liquid crystal driving, the surface of the liquid crystal alignment film cannot be rubbed uniformly, and uniform liquid crystal alignment cannot be achieved. situation.

Therefore, as another alignment treatment method for the liquid crystal alignment film without rubbing, the review of the photo-alignment method is popular.

Although there are various methods for the photo-alignment method, linearly polarized light or collimated light is used to form anisotropy in the organic film constituting the liquid crystal alignment film, and the liquid crystal is aligned according to the anisotropy.

As for the main optical alignment method, the decomposition-type optical alignment method is known. For example, the polarized ultraviolet light is irradiated to the polyimide film, and the polarization direction dependence of the ultraviolet absorption of the molecular structure is used to cause decomposition in different directions. While, borrow The polyimide remaining undecomposed aligns the liquid crystal (for example, Patent Document 1 is referred to).

Moreover, the photo-alignment method of the photo-crosslinking type is also known. For example, when polyvinyl cinnamate is used and polarized ultraviolet light is irradiated, a dimerization reaction (crosslinking reaction) occurs in the double bond portion of the two side chains parallel to the polarized light. Furthermore, the pretilt angle is expressed by irradiating polarized ultraviolet rays in an oblique direction (Non-Patent Document 1 is for reference). In addition, when a side chain type polymer having coumarin in the side chain is used, polarized ultraviolet light is irradiated to cause a photocrosslinking reaction in the coumarin portion of the side chain parallel to the polarized light, and the liquid crystal is aligned in a direction parallel to the polarization direction (non-polarized light). (Patent Document 2 is taken as a reference).

As in the above example, the alignment treatment method of the liquid crystal alignment film in the photo-alignment method does not require friction and there is no doubt about dust or static electricity. However, even the substrates of liquid crystal display elements with uneven surfaces can be subjected to alignment processing, which is a better alignment processing method for liquid crystal alignment films in industrial production processes. In addition, in the optical alignment method, since the alignment direction can be controlled by ultraviolet rays, a plurality of regions with different alignment directions are formed in the pixel (alignment division), which can compensate the viewing angle dependence.

On the other hand, the liquid crystal alignment film also plays a role of imparting a certain tilt angle (pretilt angle) to the liquid crystal, and imparting a pretilt angle has become an important issue in the development of the liquid crystal alignment film (Patent Documents 3 to 6 are for reference).

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 3893659

[Patent Document 2] Japanese Patent Laid-Open No. 02-223916

[Patent Document 3] Japanese Patent Application Laid-Open No. 04-281427

[Patent Document 4] Japanese Patent Laid-Open No. 05-043687

[Patent Document 5] Japanese Patent Application Laid-Open No. 10-333153

[Non-Patent Literature]

[Non-Patent Document 1] S. Kobayashi et al., Journal of Photopolymer Science and Technology, Vol. 8, No. 2, pp25-262(1995).

[Non-Patent Document 2] M. Shadt et al., Nature. Vol381, 212 (1996).

As described above, the photo-alignment method does not require a rubbing step compared with the conventional industrially used rubbing method as an alignment processing method for liquid crystal display elements, and therefore has a great advantage. However, compared with the rubbing method where the alignment control ability is almost constant due to rubbing, in the optical alignment method, the irradiation amount of polarized light can be changed to control the alignment control ability. However, in the optical alignment method, when it is desired to realize the alignment control ability of the field contract with the rubbing method, there are situations where a large amount of polarized light irradiation is required, and stable liquid crystal alignment cannot be achieved.

For example, in the decomposition-type photo-alignment method described in Patent Document 1, it is necessary to irradiate the polyimide film with ultraviolet light from a high-pressure mercury lamp with an output of 500 W for 60 minutes, etc., which requires a long time and a large amount of ultraviolet radiation. In addition, in the case of a dimerization type or photoisomerization type photo-alignment method, a large amount of ultraviolet radiation of about ^{several J/cm 2} to several tens of J/cm ^{2 may be required.} Furthermore, in the photo-crosslinking type or photo-isomerization type photo-alignment method, the thermal stability or light stability of the alignment of the liquid crystal is poor, and when the liquid crystal display element is made, there is a problem of poor alignment or image retention.

Therefore, in the optical alignment method, high efficiency of alignment processing or realization of stable liquid crystal alignment is pursued, and a liquid crystal alignment film or liquid crystal alignment agent that can provide a liquid crystal alignment film with high efficiency and high alignment control ability is pursued.

The object of the present invention is to provide a substrate having a liquid crystal alignment film for a liquid crystal display element that imparts alignment control ability with high efficiency and is excellent in tilt angle characteristics, and a vertical electric field drive type liquid crystal display element (such as twisted nematic (TN: Twisted) Nematic) type liquid crystal display element, vertical alignment (VA: Vertical Alignment) type liquid crystal display element, STN (Super-Twisted Nematic) type liquid crystal display element, ECB (Electrically Controlled Birefringence) type liquid crystal display element, and OCB (Optically Compensated Bend) type Liquid crystal display element).

In addition, the object of the present invention is to provide a vertical electric field drive type (such as twisted nematic liquid crystal display element, VA liquid crystal display element, STN liquid crystal display element, ECB liquid crystal display element, and ECB liquid crystal display element) with higher tilt angle characteristics. Display element and OCB type liquid crystal display element) and liquid crystal alignment film for the element. In addition, a vertical electric field drive type liquid crystal display element refers to a method in which an electric field is applied in a direction perpendicular to the substrate surface to drive liquid crystal molecules.

The inventors of the present invention worked hard to achieve the above-mentioned problems and found the following inventions.

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

<2> In the above <1>, the reactive mesogen compound of the component (B) is preferably a compound represented by the following formula (I).

P-Sp-X-MG-X-Sp-P (I) [In formula (I), P is a polymerizable group, Sp is a spacer with 1-20 carbon atoms, and X is selected from -O-, -S-, -CO-, -COO-, -OCO-, -OCO-O- groups or single bonds, MG is a mesogen group or mesogen support group, the 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 independent of each other and are 1,4-phenylene, and one or more CH groups existing in this group may be substituted by N again, or 1,4-cyclohexylene, and one CH ₂ group or two non-adjacent CH ₂ groups in the group can be substituted by O and (or) S, or 1,4-cyclohexene Group or naphthalene-2,6-diyl group, and these groups are all unsubstituted, or can be substituted by one or more halogen, cyano or nitro groups, or alkyl groups or alkyl groups with 1-7 carbon atoms. Substitution by oxy or alkanoyl. One or more of the H atoms in these groups may be substituted by F or Cl. Z ¹ and Z ² are independent of each other and are -COO-, -OCO-, -CH ₂ CH ₂ -, -OCH ₂ -, -CH ₂ O-, -CH=CH-, -CC=, -CH=CH-COO-, -OCO-CH=CH- or single bond, and m is 0, 1 Or 2)].

<3> In the above-mentioned <1> or <2>, the component (A) preferably has a photosensitive side chain that initiates photocrosslinking, photoisomerization, or photo-Fries rearrangement.

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

[In the formula, A, B, and D are independent of each other and are single bonds, -O-, -CH ₂ -, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO- O-, or -O-CO-CH=CH-; S is an alkylene group with 1 to 12 carbons, and the hydrogen atoms bonded to them can be substituted by halogen groups; T is a single bond or 1 to 12 carbons And the hydrogen atoms bonded to them can be substituted by halogen groups; Y ₁ is a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring and an alicyclic ring with 5 to 8 carbon atoms The ring selected by the hydrocarbon, or the same or different 2-6 rings selected by their substituents, are bonded through the bonding group B, and the hydrogen atoms bonded to them are independent, and can be By -COOR ₀ (where R ₀ is an alkyl group with carbon number 1 to 5), -NO ₂ , -CN, -CH=C(CN) ₂ , -CH=CH-CN, halogen group, carbon number 1 Alkyl group of ~5, or alkyloxy group of carbon number 1~5; Y ₂ is divalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, alicyclic hydrocarbon with carbon number 5~8 , And the group selected from the group formed by their combination, and the hydrogen atoms bonded to them are independent of each other, and can be -NO ₂ , -CN, -CH=C(CN) ₂ , -CH=CH- CN, halogen group, alkyl group with 1 to 5 carbons, or alkyloxy group with 1 to 5 carbons; R is alkoxy with 1 to 6 carbons, or the _{same definition as Y 1} ; X is a single bond , -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CH=CH-CO-O-, or -O-CO-CH=CH-, X of When the number is 2, X can be the same or different from each other; Cou is coumarin-6-yl or coumarin-7-yl, and the hydrogen atoms bonded to them are independent of each other, and can be replaced by -NO ₂ ,- CN, -CH=C(CN) ₂ , -CH=CH-CN, halogen group, alkyl group with 1 to 5 carbons, or alkyloxy group with 1 to 5 carbons; one of q1 and q2 is 1 and the other is 0; q3 is 0 or 1; P and Q are independent of each other and are a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon with 5 to 8 carbon atoms, And the group selected from the group formed by their combination; but, when X is -CH=CH-CO-O-, -O-CO-CH=CH-, -CH=CH- P or P on the bonding side Q is an aromatic ring; l1 is 0 or 1; l2 is an integer from 0 to 2; when both l1 and l2 are 0, when T is a single bond, A is also a single bond; when l1 is 1, when T is a single bond, B is also It is a single bond; H and I are independent of each other, and are groups selected from a combination of a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and a combination thereof."

<5> In any of the above <1> to <4>, the component (A) further has any one of the liquid crystal side chains selected from the group consisting of the following formulas (21) to (30) as good.

In the formula, A, B, R, q1 and q2 have the same definitions as above; Y ₃ is a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a nitrogen-containing heterocyclic ring, and an alicyclic ring with 5 to 8 carbon atoms The group selected from the group consisting of the formula hydrocarbon, and their combination, and the hydrogen atoms bonded to them are independent of each other, and can be -NO ₂ , -CN, halogen groups, alkyl groups with 1 to 5 carbons, Or substituted by an alkyloxy group with 1 to 5 carbon atoms; R ₃ is a hydrogen atom, -NO ₂ , -CN, -CH=C(CN) ₂ , -CH=CH-CN, halogen group, monovalent benzene ring, Naphthalene ring, biphenyl ring, furan ring, nitrogen-containing heterocyclic ring, alicyclic hydrocarbon with 5 to 8 carbons, alkyl with 1 to 12 carbons, or alkoxy with 1 to 12 carbons; l is 1~ An integer of 12, m is an integer of 0 to 2, but in formulas (23) to (26), the total of all m is 2 or more, and m1, m2, and m3 are independent of each other and are an integer of 1 to 3; R ₂ is a hydrogen atom, -NO ₂ , -CN, a halogen group, a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a nitrogen-containing heterocyclic ring, and an alicyclic hydrocarbon with 5 to 8 carbon atoms, and an alkyl group , Or alkyloxy; Z ₁₁ and Z ₁₂ are single bonds, -CO-, -CH ₂ O-, -CH=N-, -CF ₂ -.

<6> A step of forming a coating film by applying the polymer composition described in any one of the above <1> to <5> on a substrate having an electrode for liquid crystal driving by having [I]; [II] I] the step of irradiating the obtained coating film with polarized ultraviolet rays from an oblique direction; and [III] the step of heating the coating film obtained in [II]; to obtain a liquid crystal alignment film for a vertical electric field drive type liquid crystal display element endowed with alignment control ability The aforementioned method for manufacturing a substrate with a liquid crystal alignment film.

<7> A substrate having a liquid crystal alignment film for a vertical electric field drive type liquid crystal display element manufactured by the manufacturing method described in the above <6>.

<8> A vertical electric field drive type liquid crystal display element having the substrate of the above <7>.

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

<10> A step of preparing the substrate (first substrate) of the above <7>; a step of obtaining the second substrate by using the steps [I] to [III] of the above <6>; and [IV] The step of arranging the first and second substrates facing each other with the liquid crystal alignment films of the first and second substrates facing each other through the liquid crystal to obtain a liquid crystal display element; and obtaining a vertical electric field drive type liquid crystal display element of the liquid crystal display element Production method.

<11> The step [IV] is a step of arranging the first and second substrates so that the alignment directions of the first and second substrates face each other with the liquid crystal alignment films of the first and second substrates facing each other through the liquid crystal to obtain a liquid crystal display element. Method for manufacturing twisted nematic liquid crystal display elements.

<12> The vertical electric field drive type liquid crystal display element manufactured by the above <10>.

<13> The twisted nematic liquid crystal display element manufactured by the above <11>.

According to the present invention, it is possible to provide a substrate having a liquid crystal alignment film with high-efficiency alignment control ability and excellent tilt angle characteristics and a vertical electric field drive type liquid crystal display element (such as a twisted nematic liquid crystal display element, VA type Liquid crystal display element, STN type liquid crystal display element, ECB type liquid crystal display element and OCB type liquid crystal display element).

The vertical electric field drive type liquid crystal display element manufactured by the method of the present invention is efficiently endowed with an alignment control ability, so even if it is continuously driven for a long time, the display characteristics will not be impaired.

[Best form to implement the invention]

As a result of diligent research, the inventors obtained the following knowledge and completed the present invention.

The polymer composition used in the production method of the present invention is a photosensitive side chain type polymer having liquid crystallinity (hereinafter, also referred to only as side chain type high Molecule), and the coating film obtained using the aforementioned polymer composition is a film having a photosensitive side chain type polymer that can express liquid crystallinity. The coating film is not subjected to rubbing treatment, but is oriented by polarized light irradiation. However, after polarized light irradiation, the step of heating the side chain type polymer film becomes a coating film (hereinafter, also referred to as a liquid crystal alignment film) that imparts alignment control ability. At this time, the slight anisotropy exhibited by polarized light irradiation becomes the driving force, and the liquid crystal side chain polymer itself is self-organized and realigned more efficiently. As a result, as a liquid crystal alignment film, a liquid crystal alignment film that realizes high-efficiency alignment processing and is endowed with high alignment control ability can be obtained.

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

<<(A) Side chain type polymer>>

(A) Component is a photosensitive side chain type polymer which expresses liquid crystallinity in a specific temperature range.

(A) The side chain polymer reacts with light in the wavelength range of 250nm to 400nm and exhibits liquid crystallinity in the temperature range of 100°C to 300°C.

(A) The side chain type polymer preferably has a photosensitive side chain that reacts with light in the wavelength range of 250 nm to 400 nm.

(A) The side chain type polymer exhibits liquid crystallinity in the temperature range of 100°C to 300°C, and preferably has a mesogenic group.

(A) The side chain type polymer has a photosensitive side chain bonded to the main chain, which can induce cross-linking reaction, isomerization reaction, or light-Fries rearrangement after sensing light. Although the structure of the photosensitive side chain is not particularly limited, it is The structure that induces cross-linking reaction or light-Fries rearrangement after sensing light is better, and the one that causes cross-linking reaction is even better. In this case, even if exposed to external pressure such as heat, the realized alignment control ability can be stably maintained for a long period of time. The structure of the photosensitive side chain type polymer film capable of expressing liquid crystallinity is not particularly limited if it satisfies such characteristics, but it is preferable to have a rigid mesogen component in the side chain structure. 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, for example, can have a main chain and a side chain bonded to it, and the side chain has a biphenyl group, a terphenyl group, a phenylcyclohexyl group, a phenyl benzoate group, and an azobenzene group. The structure of the photosensitive group that causes the cross-linking reaction or isomerization reaction after the sensitive light of bonding to the tip part of the mesogen component, or the main chain and the side chain bonded to it, the side chain also becomes It has a mesogen composition and has a structure of a phenyl benzoate group that undergoes a light-Fries rearrangement reaction.

More specific examples of the structure of the photosensitive side chain type polymer that can express liquid crystallinity include hydrocarbons, (meth)acrylates, itaconates, fumarates, maleates, and α-substrates. The main chain consisting of at least one selected from the group of radically polymerizable groups such as methyl-γ-butyrolactone, styrene, vinyl, maleimide, norbornene, and silicone, It is preferable to have a structure with a photosensitive side chain composed of at least one of the following formulas (1) to (6).

In the formula, A, B, and D are independent of each other and are single bonds, -O-, -CH ₂ -, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O -, or -O-CO-CH=CH-; S is an alkylene group with 1 to 12 carbons, and the hydrogen atoms bonded to them can be substituted by halogen groups; T is a single bond or one with 1 to 12 carbons Alkylene, and the hydrogen atoms bonded to them can be substituted by halogen groups; Y ₁ is a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring and an alicyclic hydrocarbon with 5 to 8 carbon atoms The selected ring, or the same or different 2-6 rings selected by their substituents, are bonded through the bonding group B, and the hydrogen atoms bonded to them are independent and can be -COOR ₀ (where R ₀ is an alkyl group with carbon number of 1 to 5), -NO ₂ , -CN, -CH=C(CN) ₂ , -CH=CH-CN, halogen group, carbon number of 1~ Alkyl group 5, or alkyloxy group with 1 to 5 carbons; Y ₂ is a divalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, alicyclic hydrocarbon with 5 to 8 carbons, And the group selected from the group formed by their combination, and the hydrogen atoms bonded to them are independent, can be -NO ₂ , -CN, -CH=C(CN) ₂ , -CH=CH-CN , Halogen group, alkyl group with 1 to 5 carbons, or alkyloxy group with 1 to 5 carbons; R is an alkoxy group with 1 to 6 carbons, or the _{same definition as Y 1} ; X is a single bond, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CH=CH-CO-O-, or -O-CO-CH=CH-, the number of X When it is 2, X can be the same or different from each other; Cou is coumarin-6-yl or coumarin-7-yl, and the hydrogen atoms bonded to them are independent of each other and can be replaced by -NO ₂ , -CN , -CH=C(CN) ₂ , -CH=CH-CN, halogen group, C1-C5 alkyl group, or C1-C5 alkyloxy group substitution; q1 and q2, one of them is 1 And the other is 0; q3 is 0 or 1; P and Q are independent of each other and are a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon with 5 to 8 carbon atoms, and The group selected from the group formed by their combination; but, when X is -CH=CH-CO-O-, -O-CO-CH=CH-, -CH=CH- P or Q on the bonding side Is an aromatic ring; l1 is 0 or 1; l2 is an integer from 0 to 2; when both l1 and l2 are 0, when T is a single bond, A is also a single bond; when l1 is 1, when T is a single bond, B is also Single bond; H and I are each independent, and are groups selected from a combination of divalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, and combinations thereof.

The side chain is preferably any one of photosensitive side chains selected from the group consisting of the following formulas (7) to (10).

In the formula, A, B, D, Y ₁ , X, Y ₂ , and R have the same definitions as above; l is an integer from 1 to 12; m is an integer from 0 to 2, m1, m2 are an integer from 1 to 3 ; N is an integer from 0 to 12 (but B is a single bond when n=0).

The side chain is preferably any one of photosensitive side chains selected from the group consisting of the following formulas (11) to (13).

In the formula, A, X, 1, m and R have the same definitions as above.

The side chain is preferably a photosensitive side chain represented by the following formula (14) or (15).

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

The side chain is preferably a photosensitive side chain represented by the following formula (16) or (17).

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

In addition, the side chain is preferably a photosensitive side chain represented by the following formula (18) or (19).

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

R ₁ is a hydrogen atom, -NO ₂ , -CN, -CH=C(CN) ₂ , -CH=CH-CN, a halogen group, an alkyl group with 1 to 5 carbons, or an alkyl group with 1 to 5 carbons Oxy.

The side chain is preferably a photosensitive side chain represented by the following formula (20).

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

In addition, the (A) side chain type polymer preferably has any one liquid crystal side chain selected from the group consisting of the following formulas (21) to (30).

In the formula, A, B, R, q1 and q2 have the same definitions as above; Y ₃ is a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a nitrogen-containing heterocyclic ring, and an alicyclic ring with 5 to 8 carbon atoms The group selected from the group consisting of the formula hydrocarbon, and their combination, and the hydrogen atoms bonded to them are independent of each other, and can be -NO ₂ , -CN, halogen groups, alkyl groups with 1 to 5 carbons, Or substituted by an alkyloxy group with 1 to 5 carbon atoms; R ₃ is a hydrogen atom, -NO ₂ , -CN, -CH=C(CN) ₂ , -CH=CH-CN, halogen group, monovalent benzene ring, Naphthalene ring, biphenyl ring, furan ring, nitrogen-containing heterocyclic ring, alicyclic hydrocarbon with 5 to 8 carbons, alkyl with 1 to 12 carbons, or alkoxy with 1 to 12 carbons; l is 1~ An integer of 12, m is an integer of 0 to 2, but in formulas (23) to (26), the sum of all m is 2 or more, and m1, m2, and m3 are independent of each other and are an integer of 1 to 3; R ₂ is a hydrogen atom, -NO ₂ , -CN, a halogen group, a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a nitrogen-containing heterocyclic ring, and an alicyclic hydrocarbon with 5 to 8 carbon atoms, and an alkyl group , Or alkyloxy; Z ₁₁ and Z ₁₂ are single bonds, -CO-, -CH ₂ O-, -CH=N-, -CF ₂ -.

<<Preparation method of photosensitive side chain polymer>>

The photosensitive side chain type polymer which can express the said liquid crystallinity can be obtained by polymerizing the said photoreactive side chain monomer which has a photosensitive side chain, and a liquid crystal side chain monomer.

[Photoreactive side chain monomer]

The photoreactive side chain monomer refers to a monomer that can form a polymer having a photosensitive side chain at the side chain portion of the polymer when forming a polymer.

The photoreactive group possessed by the side chain preferably has the following structure and its derivatives.

More specific examples of photoreactive side chain monomers include hydrocarbons, (meth)acrylates, itaconates, fumarates, maleic acid, α-methylene-γ-butyrolactone, Free radical polymerizable groups such as styrene, vinyl, maleimide, norbornene, and a polymerizable group composed of at least one selected from the group of silicones, and the above formulas (1)~( 6) A photosensitive side chain composed of at least one type of, for example, a photosensitive side chain composed of at least one of the above formulas (7) to (10), and the above formula (11) to (13) at least one photosensitive side chain, the photosensitive side chain represented by the above formula (14) or (15), the photosensitive side chain represented by the above formula (16) or (17), the above The photosensitive side chain represented by the formula (18) or (19) and the photosensitive side chain represented by the above formula (20) preferably have a structure.

With regard to such photoreactive side chain monomers, it is preferable to perform dimerization reaction or isomerization reaction when irradiated with polarized ultraviolet rays. Examples of such monomers include monomers selected from the following formulas M1-1 to M1-22.

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

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

[Liquid crystal side chain monomer]

The liquid crystal side chain single system refers to a monomer in which a polymer derived from the monomer exhibits liquid crystallinity, and the polymer can form a mesogenic group at a side chain site.

The mesogen group in the side chain can be biphenyl or phenyl benzoate It is the base of the mesogen structure alone or the side chains of benzoic acid are hydrogen-bonded to each other to form the base of the mesogen structure. The mesogen group of the side chain preferably has the following structure.

More specific examples of liquid crystalline side chain monomers include hydrocarbon, (meth)acrylate, itaconate, fumarate, maleic acid, α-methylene-γ-butyrolactone, benzene Radical polymerizable groups such as ethylene, vinyl, maleimide, norbornene, and at least one polymerizable group selected from the group of silicones and the above formulas (21) to (30) The structure of the side chain formed by at least one of them is preferable.

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

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

(A) The side chain type polymer can be obtained by the copolymerization reaction of the above-mentioned photoreactive side chain monomer expressing liquid crystallinity. In addition, it can be achieved by the copolymerization of a photoreactive side chain monomer that does not exhibit liquid crystallinity and a liquid crystalline side chain monomer, or a copolymerization of a photoreactive side chain monomer exhibiting liquid crystallinity and a liquid crystalline side chain monomer And get. Furthermore, it can be copolymerized with other monomers within the range of performance ability that does not impair the liquid crystallinity.

In terms of other monomers, for example, an industrially available monomer capable of undergoing radical polymerization can be mentioned.

Specific examples of other monomers include unsaturated carboxylic acids, acrylate compounds, methacrylate 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.

Acrylate compounds include, for example, methacrylate, ethacrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthryl acrylate, anthryl methacrylate, phenyl acrylate, 2,2,2-Trifluoroethyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, isobornyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate , 2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, 3-methoxybutyl acrylate, 2-methyl-2-gold Mandyl acrylate, 2-propyl-2-adamantyl acrylate, 8-methyl-8-tricyclodecyl acrylate, 8-ethyl-8-tricyclodecyl acrylate, etc.

The methacrylate compound includes, for example, methacrylate, ethyl methacrylate, isopropyl methacrylate, benzyl methacrylate, naphthyl methacrylate, and anthryl methacrylate. Esters, anthracenyl methacrylate, phenyl methacrylate, 2,2,2-trifluoroethyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl Methacrylate, 2-methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2-ethoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 3-methoxybutyl methacrylate, 2-methyl-2-adamantyl methacrylate, 2-propyl-2-adamantyl methacrylate, 8-methyl-8-tricyclodecane Methyl methacrylate, 8-ethyl-8-tricyclodecyl methacrylate, etc.

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 the styrene compound include styrene, methylstyrene, chlorostyrene, and bromostyrene.

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

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

The content of liquid crystal side chains in the side chain polymer of the present invention, from the viewpoint of liquid crystal alignment, is preferably 90 mol% or less, 5 mol% to 80 mol%, and 10 mol% to 70 mol%. Mole% is even better.

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

The manufacturing method of the side chain type polymer of this embodiment is not particularly limited, and a common method used in industry can be used. Specifically, it can be produced by cationic polymerization, radical polymerization, or anionic polymerization using a vinyl group of a liquid crystal side chain monomer or a photoreactive side chain monomer. Among these, from the viewpoints of ease of reaction control, etc., radical polymerization is particularly preferred.

Regarding the polymerization initiator for radical polymerization, conventional compounds such as a radical polymerization initiator or a reversible addition-cracking type chain transfer (RAFT) polymerization reagent can be used.

The radical thermal polymerization initiator is a compound that generates radicals by heating to a temperature above the decomposition temperature. Such radical thermal polymerization initiators, such as ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), diacetyl peroxides (acetyl peroxide , Benzyl peroxide, etc.), hydrogen peroxide (hydrogen peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl hydroperoxide, etc.) Base peroxide, dicumyl peroxide, dilaurel peroxide, etc.), peroxyketals (dibutylperoxycyclohexane, etc.), alkyl Peresters (peroxyneodecanoic acid-tert-butyl ester, peroxypivalic acid-tert-butyl ester, peroxy2-ethylcyclohexane acid-tert-pentyl ester, etc.), persulfuric acid Salts (potassium persulfate, sodium persulfate, ammonium persulfate, etc.), azo compounds (azobisisobutyronitrile, and 2,2'-bis(2-hydroxyethyl)azobisisobutyronitrile, etc.) ). Such a radical thermal polymerization initiator can be used singly or in combination of two or more kinds.

The radical photopolymerization initiator is a compound that starts radical polymerization upon light irradiation, and is not particularly limited. Such radical photopolymerization initiators include, for example, benzophenone, Michler’s ketone, 4,4'-bis(diethylamino)benzophenone, xanthone, thioxanthone, iso Propyl xanthone, 2,4-diethyl thioxanthone, 2-ethylanthraquinone, acetophenone, 2-hydroxy-2-methylpropanebenzene, 2-hydroxy-2-methyl-4 '-Isopropyl propyl benzene, 1-hydroxycyclohexyl phenyl ketone, isopropyl benzoin ether, isobutyl benzoin ether, 2,2-diethoxyacetophenone, 2,2-dimethoxy -2-Phenylacetophenone, camphorquinone, benzoanthrone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one, 2- Benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 4-dimethylaminobenzoic acid ethyl ester, 4-dimethylaminobenzoic acid Isoamyl ester, 4,4'-bis(t-butylperoxycarbonyl)benzophenone, 3,4,4'-tris(t-butylperoxycarbonyl)benzophenone, 2 ,4,6-Trimethylbenzyldiphenylphosphine oxide, 2-(4'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(3',4'-Dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2',4'-Dimethoxystyrene Yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine , 2-(4'-Pentyloxystyryl) -4,6-bis(trichloromethyl)-s-triazine, 4-[pN,N-bis(ethoxycarbonylmethyl)]-2,6-bis(trichloromethyl)-s- Triazine, 1,3-bis(trichloromethyl)-5-(2'-chlorophenyl)-s-triazine, 1,3-bis(trichloromethyl)-5-(4'-methyl) Oxyphenyl)-s-triazine, 2-(p-dimethylaminostyryl)benzoxazole, 2-(p-dimethylaminostyryl)benzothiazole, 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'-tetra(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-dimethylaminopropyl)carbazole, 3,6-bis(2-methyl 2-morpholinopropionyl)-9-n-dodecylcarbazole, 1-hydroxycyclohexyl phenyl 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'-bis(methoxycarbonyl)-4,4'-bis(t-butyl Peroxycarbonyl)benzophenone, 3,4'-bis(methoxycarbonyl)-4,3'-bis(t-butylperoxycarbonyl)benzophenone, 4,4'-bis (Methoxycarbonyl)-3,3'-bis(t-butylperoxycarbonyl)benzophenone, 2-(3-methyl-3H-benzothiazole-2-ylidene)-1-naphthalene -2-yl-ethanone, or 2-(3-methyl-1,3-benzothiazole-2(3H)-ylidene)-1-(2-benzyl)ethanone, etc. These compounds can be used alone or in combination of two or more kinds.

The radical polymerization method is not particularly limited, and emulsion polymerization can be used Method, suspension polymerization method, dispersion polymerization method, precipitation polymerization method, bulk polymerization method, solution polymerization method, etc.

The organic solvent used in the polymerization reaction of the photosensitive side chain type polymer that can express liquid crystallinity is not particularly limited if it dissolves the produced polymer. Specific examples thereof include the following.

For example, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactone, Dimethyl sulfide, tetramethyl urea, pyridine, dimethyl sulfide, hexamethyl sulfide, γ-butyrolactone, isopropyl alcohol, methoxymethyl pentanol, dipentene, ethyl pentene Methyl 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 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 monoacetic acid Ester monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isopropyl ether Butyl ether, diisobutylene, pentyl acetate, butylbutyl ester, 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 Base ester, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, 3-ethoxy Methyl ethyl propionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, 3-methoxy Butyl propionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N,N-dimethylpropaneamide, 3-ethoxy -N,N-dimethylpropaneamide, 3-butoxy-N,N-dimethylpropaneamide, etc.

These organic solvents can be used alone or in combination. Furthermore, even if it is a solvent that does not dissolve the produced polymer, it can be used in combination with the above-mentioned organic solvent in a range where the produced polymer does not precipitate.

In addition, in radical polymerization, since oxygen in the organic solvent is a cause of hindering the polymerization reaction, the organic solvent is preferably used as degassed as possible.

The polymerization temperature during radical polymerization can be selected at any temperature 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 better. It is 1% by mass to 50% by mass, more preferably 5% by mass to 30% by mass. The reaction is carried out at a high concentration in the initial stage, and then an organic solvent can be added.

In the above-mentioned radical polymerization reaction, the ratio of the radical polymerization initiator to that of the more monomers will decrease the molecular weight of the polymer obtained, and the smaller the ratio of the radical initiator will increase the molecular weight of the polymer obtained. The polymerized monomer is preferably 0.1 mol% to 10 mol%. During the polymerization, various monomer components, solvents, initiators, etc. may be added.

[Recycling of polymers]

The reaction solution of the photosensitive side chain type polymer capable of expressing liquid crystallinity obtained by the above reaction, in the case of recovering the produced polymer, the reaction solution may be poured into a poor solvent and the polymer may be precipitated. Examples of poor solvents used for precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, and diethyl ether. , Methyl ethyl ether, water, etc. After the polymer precipitated by inputting the poor solvent is filtered and recovered, it can be dried under normal pressure or reduced pressure at normal temperature or by heating. In addition, by re-dissolving the polymer recovered by precipitation in an organic solvent, and repeating the reprecipitation recovery operation 2 to 10 times, impurities in the polymer can be reduced. For the poor solvents at this time, such as alcohols, ketones, hydrocarbons, etc., using more than 3 types of poor solvents selected from these can further improve the efficiency of purification, so it is preferred.

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

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

In a preferred aspect of the present invention, the reactive mesogen 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) [Formula (I) In ), P is a polymerizable group, Sp is a spacer with 1-20 carbon atoms, and X is selected from -O-, -S-, -CO-, -COO-, -OCO-, -OCO-O -Is a group or a single bond, MG is a mesogen group or a mesogen support group, and the group is preferably selected by the following formula (II): -(A ¹ -Z ¹ ) _m -A ² -Z ² -A ³ -(II)

(In the formula, A ¹ , A ² and A ³ are independent of each other and are 1,4-phenylene groups, and one or more CH groups existing in this group may be substituted by N again, or 1,4 -Cyclohexenylene, and one CH ₂ group or two non-adjacent CH ₂ groups in the group can be substituted by O and (or) S, or 1,4-cyclohexenylene or naphthalene -2,6-diyl, and all of these groups are unsubstituted, or may be substituted by one or more halogen, cyano or nitro groups, or alkyl, alkoxy or carbon atoms with 1-7 Alkyl substituted, one or more of the H atoms in these groups may be substituted by F or Cl, and Z ¹ and Z ² are independent of each other and are -COO-, -OCO-, -CH ₂ CH _2- , -OCH ₂ -, -CH ₂ O-, -CH=CH-, -CC=, -CH=CH-COO-, -OCO-CH=CH- or single bond, and m is 0, 1 or 2) ].

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

Bicyclic and tricyclic mesogen compounds are preferred.

Halogen is preferably F or Cl.

In the compound represented by formula I, with MG in formula II, Z ¹ and Z ² are -COO-, -OCO-, -CH ₂ -CH ₂ -, -CH=CH-COO-, -OCO-CH= CH- or single bond compounds are particularly preferred.

The small groups of preferred mesogen groups represented by formula II are as follows. For brevity, in these groups, Phe is 1,4-phenylene, and PheL is 1,4-phenylene substituted with at least one group L, where L is F, Cl or CN, or has a carbon atom 1 to 4, and can be fluorinated alkyl, alkoxy or alkanoyl, and Cyc is trans-1,4-cyclohexylene.

Among these preferred groups, Z ¹ and Z ² have the meanings shown in formula I above. Preferably, Z ¹ and Z ² are -COO-, -OCO-, -CH ₂ CH ₂ -or -CH=CH-COO-.

L is preferably F, Cl, CN, NO ₂ , CH ₃ , C ₂ H ₅ , OCH ₃ , OC ₂ H ₅ , COCH ₃ , COC ₂ H ₅ , CF ₃ , OCF ₃ , OCHF ₂ , OCF ₅ , especially Preferred are F, Cl, CN, CH ₃ , C ₂ H ₅ , OCH ₃ , COCH ₃ and OCF ₃ , and most _{preferred are F, CH 3} , OCH ₃ and COCH ₃ .

The compound selected by MG with the following formula is particularly preferred:

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

In these better formulas, base:

，再進一步為

，且此等之基中，L為各自獨立，具有上述意義之一。 Very good

, And then further

, And in these bases, L is each independent and has one of the above-mentioned meanings.

The R present in these preferred compounds has one of the meanings represented by _{P-(Sp) n -.}

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

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

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

As the spacer Sp, all groups known to the industry can be used for this purpose. The spacer Sp is preferably bonded to the polymerizable group P through an ester or ether group, or a single bond. The spacer Sp preferably has 1 to 20 carbon atoms, especially 1 to 12 carbon atoms, and further, one CH ₂ group or two or more non-adjacent CH ₂ groups in the group may be -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- substituted linear or branched chain alkylene.

Representative spacers, such as -(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 -, and in these bases, o is an integer of 2-12, and r is an integer of 1-3.

Preferred spacers, such as ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylylene, decylene, undecylenyl, and dodecylene , Octadecylene, ethyleneoxyethylene, ethyleneoxybutylene, ethylene-thioethylene, ethylene-N-methyliminoethylene and 1-methyl Alkylene.

In formula I, the two P, Sp and X may be the same or different.

Representative examples of the polymerizable mesogen compound represented by Formula I are listed below. However, this list is only an illustration, and does not limit the scope of the present invention.

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

These compounds are known in the literature or are commercially available.

<<(C)Organic solvent>>

The organic solvent used in the polymer composition used in the present invention is not particularly limited if it is an organic solvent that dissolves the resin component. Specific examples are listed below.

For example, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactone, 2-pyrrolidone , N-ethylpyrrolidone, N-vinylpyrrolidone, dimethyl sulfide, tetramethylurea, pyridine, dimethyl sulfide, hexamethyl pyrrolidone, γ-butyrolactone, 3-methyl Oxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, 1, 3-Dimethyl-imidazolinone, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethylene carbonate, Propylene carbonate, diglyme, 4-hydroxy-4-methyl-2-pentanone, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl Ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, Dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether Wait. These can be used alone or in combination.

<Polymer composition>

The polymer composition is applied to the electrode forming side of the above-mentioned substrate.

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

[Preparation of polymer composition]

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

In the polymer composition of this embodiment, the aforementioned resin components may all be the above-mentioned photosensitive side chain type polymer capable of expressing liquid crystallinity, but other than them may be mixed without impairing the range of liquid crystal expressing ability and photosensitive performance polymer. At this time, the content of other polymers in the resin component is 0.5% by mass to 80% by mass, preferably 1% by mass to 50% by mass.

Such other polymers include, for example, polymers of poly(meth)acrylate, polyamide acid, polyimide, etc., which are not photosensitive side chain type polymers that can express liquid crystallinity, and the like.

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 solvents or compounds that improve film thickness uniformity or surface smoothness when the polymer composition is applied, and compounds that improve the adhesion between the liquid crystal alignment film and the substrate, but are not limited to these.

Specific examples of solvents (lean solvents) that improve the uniformity of film thickness or surface smoothness can be given as follows.

Such as 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 mono Propyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl Ether, diisobutylene, pentyl acetate, butylbutyl, 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, acetone Methyl ester, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxy Propionic acid, 3-methoxypropionic acid, 3-methoxypropionic acid propyl ester, 3-methoxypropionic acid butyl ester, 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-ethoxypropane (Oxy)propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate and other solvents with low surface tension.

These poor solvents can be one type or a mixture of multiple types. When the above-mentioned solvents are used, so as not to significantly reduce the solubility of the entire solvent contained in the polymer composition, 5 mass% to 80 mass% of the total solvent is preferred, and 20 mass% to 60 mass% is more preferred.

As for the compound that improves the uniformity of the film thickness or the surface smoothness, for example, a fluorine-based surfactant, a silicone-based surfactant, and a non-ionic surfactant, etc. can be mentioned.

More specifically, for example, EFTOP (registered trademark) 301, EF303, EF352 (manufactured by Thochem Products.), MEGAFAC (registered trademark) F171, F173, R-30 (manufactured by DIC Corporation), Fluorad FC430, FC431 (Sumitomo 3M Company), Asahiguard (registered trademark) AG710 (made by Asahi Glass Co., Ltd.), Surflon (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, SC106 (made by AGC SEIMI CHEMICAL CO., LTD), etc. The use ratio of these surfactants is preferably 0.01 to 2 parts by mass, and more preferably 0.01 to 1 part by mass relative to 100 parts by mass of the resin component contained in the polymer composition.

As for specific examples of the compound that improves the adhesion between the liquid crystal alignment film and the substrate, the following functional silane-containing compounds can be exemplified.

For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane Alkyl, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3 -Ureaylpropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-amine Triethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4, 7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-Triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyl trimethoxysilane, N-benzyl-3-aminopropyl three Ethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(ethylene oxide)-3-amino Propyl trimethoxysilane, N-bis(oxyethylene)-3-aminopropyl triethoxysilane, etc.

Furthermore, in addition to the improvement of the adhesion between the substrate and the liquid crystal alignment film to prevent the reduction of electrical characteristics caused by the backlight when forming the liquid crystal display element, the polymer composition may contain the following phenolic resins or epoxy-containing compounds Of additives. Specific phenol resin additives are shown below, but are not limited to this structure.

Specific epoxy-containing compounds, such as 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 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 and the like.

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

As an additive, a photosensitizer can also be used. Colorless sensitizers and triplet sensitizers are preferred.

In terms of photosensitizers, such as aromatic nitro compounds, coumarins (7-diethylamino-4-methylcoumarin, 7-hydroxy4-methylcoumarin), coumarin ketones, Carbonyl biscoumarin, aromatic 2-hydroxy ketone, and Amino substituted aromatic 2-hydroxy ketones (2-hydroxybenzophenone, mono- or di-p-(dimethylamino)-2-hydroxybenzophenone), acetophenone, anthraquinone, Xanthone, thioxanthone, benzoanthrone, thiazoline (2-benzylmethylene-3-methyl-β-naphthazoline, 2-(β-benzylmethylene )-3-methylbenzothiazoline, 2-(α-benzylmethylene)-3-methylbenzothiazoline, 2-(4-biphenylmethylene)-3-methyl Benzothiazoline, 2-(β-benzylmethylene)-3-methyl-β-naphthazoline, 2-(4-biphenylmethylene)-3-methyl- β-naphthazoline, 2-(p-fluorobenzylmethylene)-3-methyl-β-naphthazoline), oxazoline (2-benzylmethylene-3 -Methyl-β-naphthoxazoline, 2-(β-benzylmethylene)-3-methylbenzoxazoline, 2-(α-benzylmethylene)- 3-methylbenzoxazoline, 2-(4-biphenylmethylene)-3-methylbenzoxazoline, 2-(β-benzylmethylene)-3-methyl -Β-naphthoxazoline, 2-(4-biphenylmethylene)-3-methyl-β-naphthoxazoline, 2-(p-fluorobenzamethylene) -3-methyl-β-naphthoxazoline), benzothiazole, nitroaniline (m- or p-nitroaniline, 2,4,6-trinitroaniline) or nitroacenaphthylene (5 -Nitroacenaphthylene), (2-[(m-hydroxy-p-methoxy)styryl]benzothiazole, benzoin alkyl ether, N-alkylated futalone, acetophenone ketal ( 2,2-Dimethoxyphenylethanone), naphthalene, anthracene (2-naphthalene methanol, 2-naphthalene carboxylic acid, 9-anthracene methanol, and 9-anthracene acid), benzopiperan, azoindole Doxyazine, methyl coumarin, etc.

Preferably aromatic 2-hydroxy ketone (benzophenone), coumarin, coumarin ketone, carbonyl biscoumarin, acetophenone, anthraquinone, xanthone, thioxanthone, and acetophenone Ketal.

The method for manufacturing a substrate with the liquid crystal alignment film of the present invention includes: [I] will contain (A) a photosensitive side chain polymer that exhibits liquid crystallinity in a specified temperature range, (B) a reactive mesogen compound, and an organic solvent The step of coating the polymer composition of the polymer composition on the substrate with the electrode for liquid crystal driving to form a coating film; [II] the step of irradiating the coating film obtained by [I] with polarized ultraviolet rays; and [III] the step of applying [II] The step of heating the coating film.

Through the above steps, a vertical electric field driven liquid crystal display element (such as a twisted nematic liquid crystal display element, a vertical alignment liquid crystal display element, an STN liquid crystal display element, an ECB liquid crystal display element, and an OCB can be obtained that has been given alignment control capabilities. Type liquid crystal display element) uses a liquid crystal alignment film, and a substrate having the liquid crystal alignment film can be obtained.

In addition to the substrate (first substrate) obtained above, by preparing a second substrate, a vertical electric field drive type liquid crystal display element (such as a twisted nematic liquid crystal display element, a vertical alignment type liquid crystal display element, an STN liquid crystal display element) can be obtained. Display element, ECB type liquid crystal display element and OCB type liquid crystal display element).

For the second substrate, by using the above steps [I] to [III], a second substrate having a liquid crystal alignment film to which alignment control ability is imparted can be obtained.

The method for manufacturing a vertical electric field drive type liquid crystal display element has [IV] the first and second substrates obtained above are arranged so that the liquid crystal alignment films of the first and second substrates face each other through the liquid crystal, and are obtained by opposing Step to the liquid crystal display element. At this time, the substrate with the first and second alignment films obtained above and the inclination angle of 10 to 50 degrees are arranged so that the rubbing direction (alignment of the liquid crystal) is parallel and the same direction (parallel alignment), then OCB-type liquid crystal display elements can be obtained. In the same way, using two substrates with an alignment film with an inclination angle of 80 to 90 degrees, a vertical alignment type liquid crystal display element can be obtained. The rubbing directions are perpendicular to each other, that is, the twisted nematic liquid crystal display element is arranged in a manner twisted at about 90 degrees, and the STN liquid crystal display element is obtained when the rubbing direction is twisted at about 260 degrees. Furthermore, by arranging the substrates with the first and second alignment films obtained above in such a manner that the alignment processing directions are parallel to each other and opposite (anti-parallel), an ECB-type liquid crystal display element can be obtained.

Hereinafter, each step of [I] to [III] and [IV] included in the manufacturing method of the present invention will be explained.

<Step [I]>

In step [I], a substrate with electrodes for driving liquid crystals is coated with (A) a photosensitive side chain polymer that exhibits liquid crystallinity in a specified temperature range, (B) a reactive mesogen compound, and an organic solvent. The polymer composition forms a coating film.

<Substrate>

Although the substrate is not particularly limited, when the manufactured liquid crystal display element is a transmissive type, it is preferable to use a highly transparent substrate. In this case, there are no particular restrictions, and glass substrates, acrylic substrates, polycarbonate substrates, etc. can be used The plastic substrate and so on.

The electrode for liquid crystal driving is preferably ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), or the like. In addition, in the reflective liquid crystal display element, if only a single-sided substrate is used, an opaque material such as a silicon wafer may also be used. In this case, a light-reflecting material such as aluminum may also be used for the electrode.

The method of forming electrodes on the substrate can use conventionally known methods.

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

The coating method is generally carried out by screen printing, offset printing, flexographic printing, or inkjet method in the industry. Other coating methods include dipping, roll coating, slit coating, spinning (spin coating), or spraying methods. These can be used according to the purpose.

After coating the polymer composition on the substrate with liquid crystal drive electrodes, use heating means such as a hot plate, thermal cycle oven or IR (infrared) oven at 50~230℃, preferably 50~200℃ , 0.4 minutes to 60 minutes, preferably 0.5 minutes to 10 minutes to evaporate the solvent to obtain a coating film. The drying temperature at this time is preferably lower than the liquid crystal phase expression temperature of the side chain type polymer.

If the thickness of the coating film is too thick, it will become disadvantageous on the power consumption surface of the liquid crystal display element. If it is too thin, the reliability of the liquid crystal display element may decrease, so it is preferably 5nm~300nm, more preferably 10nm~150nm .

Furthermore, after the step [I], a step of cooling the substrate on which the coating film is formed to room temperature may be provided before the subsequent step [II].

<Step [II]>

In step [II], the coating film obtained in step [I] is irradiated with polarized ultraviolet rays from an oblique direction. When irradiating the film surface of the coating film with polarized ultraviolet rays, the polarizing plate is irradiated with polarized ultraviolet rays from a certain direction relative to the substrate. Regarding the ultraviolet rays used, ultraviolet rays with a wavelength in the range of 100nm to 400nm can be used. It is preferable to select the most appropriate wavelength according to the type of coating film used and the transmission filter or the like. However, for example, it is possible to select ultraviolet light in the range of 290nm~400nm in a way that can selectively initiate the photocrosslinking reaction. For ultraviolet light, for example, light emitted from a high-pressure mercury lamp can be used.

The amount of polarized ultraviolet radiation varies depending on the coating film used. The irradiation amount is based on the maximum value of the difference ΔA between the ultraviolet absorbance in the direction parallel to the polarization direction of the polarized ultraviolet light and the ultraviolet absorbance in the vertical direction in the coating film (hereinafter, also referred to as ΔAmax), which is 1%~70 The range of% is better, and the range of 1% to 50% is more preferable.

The irradiation direction of polarized ultraviolet rays is usually 1°~89° relative to the substrate, but preferably 10°~80°, and particularly preferably 20°~70°. If the angle is too small, the pretilt angle will decrease, and if it is too large, the pretilt angle will increase.

Regarding the method of adjusting the irradiation direction to the above-mentioned angle, there are a method of tilting the substrate itself and a method of tilting the light source, but tilting the light source itself is preferable from the viewpoint of productivity.

<Step [III]>

In step [III], heat the polarized ultraviolet coating in step [II] membrane. After heating, it can give the coating film alignment control ability.

Heating can use heating means such as hot plate, thermal cycle oven or IR (infrared) oven. The heating temperature can be determined by considering the temperature of the coating film used to express the liquid crystallinity.

The heating temperature is preferably within the temperature range at which the side chain polymer exhibits liquid crystallinity (hereinafter referred to as the liquid crystallinity expression temperature). In the case of a thin film surface like a coating film, the liquid crystal expression temperature of the coating film surface is expected to be lower than the liquid crystal expression temperature when the photosensitive side chain polymer that can express liquid crystal properties is observed in bulk. Therefore, the heating temperature is better within the temperature range of the liquid crystal display temperature of the coating film surface. That is, the temperature range of the heating temperature after the polarized ultraviolet radiation is 10°C lower than the lower limit of the temperature range of the liquid crystal expression temperature of the side chain polymer used as the lower limit, and 10°C lower than the upper limit of the liquid crystal temperature range The temperature within the upper limit range is preferable. If the heating temperature is lower than the above-mentioned temperature range, the amplification effect of the coating film due to the thermal anisotropy tends to become insufficient. If the heating temperature is higher than the above-mentioned temperature range, the state of the coating film may become nearly equal. The tendency of sexual liquid state (isotropic phase). In this case, it may become difficult to re-orientate in one direction due to self-organization.

In addition, the liquid crystallinity expression temperature is higher than the glass transition temperature (Tg) of the side chain polymer or the surface of the coating film from the solid phase to the liquid crystal phase, and when the liquid crystal phase is converted to the homogeneous phase (equal square) The temperature below the mean squareness phase transition temperature (Tiso) of phase).

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

By having the above steps, in the manufacturing method of the present invention, it is possible to efficiently introduce anisotropy to the coating film. However, the substrate with the liquid crystal alignment film can be manufactured efficiently.

<Step [IV]>

The step [IV] includes the two substrates obtained in [III] provided with a substrate on the side where the liquid crystal alignment film is formed facing each other, a liquid crystal layer provided between the substrates, and a liquid crystal of the present invention provided between the substrate and the liquid crystal layer The liquid crystal display element of the liquid crystal cell of the liquid crystal alignment film formed by the alignment agent. Such a vertical electric field drive type liquid crystal display element of the present invention may include, for example, a twisted nematic (TN: Twisted Nematic) method, a vertical alignment (VA: Vertical Alignment) method, or an STN (Super-Twisted Nematic) type liquid crystal display element. ECB (Electrically Controlled Birefringence) type liquid crystal display elements and OCB alignment (OCB: Optically Compensated Bend), etc.

An example of the production of a liquid crystal cell or a liquid crystal display element can be, for example, preparing the above-mentioned first and second substrates, spreading spacers on the liquid crystal alignment film of one of the substrates, and using the liquid crystal alignment film surface as the inner side to obtain a twisted nematic In the case of components, the ultraviolet exposure directions are perpendicular to each other. To obtain other components, the method of bonding another substrate as described above to inject the liquid crystal under reduced pressure and then sealing, or dripping liquid crystal on the surface of the liquid crystal alignment film with spacers Then, the method of sealing after bonding the substrate. The diameter of the spacer at this time is preferably 1 μm to 30 μm, more preferably 2 μm to 10 μm. The diameter of the spacer determines the distance between a pair of substrates sandwiching the liquid crystal layer, that is, the thickness of the liquid crystal layer.

The obtained liquid crystal display element is further preferably subjected to an annealing treatment for alignment stability. The heating temperature is the phase transition temperature of the liquid crystal, preferably 10 to 160°C, more preferably 50 to 140°C.

The method of manufacturing a substrate with a coating film of the present invention is to apply a polymer composition on a substrate to form a coating film, and then irradiate polarized ultraviolet rays. Next, a substrate with a liquid crystal alignment film is produced by heating to realize the introduction of high-efficiency anisotropy into the side chain polymer film and the ability to control the alignment of the liquid crystal.

The coating film used in the present invention utilizes the principle of molecular realignment caused by the photoreaction of the side chain and the self-organization based on liquid crystallinity to achieve high-efficiency introduction of anisotropy to the coating film. In the production method of the present invention, when the side chain type polymer has a photocrosslinkable group as the photoreactive group structure, the side chain type polymer is used to form a coating film on the substrate, and then polarized ultraviolet rays are irradiated. After heating, a liquid crystal display element was produced.

Therefore, the coating film used in the method of the present invention can be made into a liquid crystal alignment film with excellent alignment control ability by sequentially irradiating the coating film with polarized ultraviolet rays and heating treatment to efficiently introduce anisotropy.

On the other hand, the coating film used in the method of the present invention optimizes the amount of ultraviolet rays that irradiate the coating film with polarized light and the heating temperature in the heat treatment. With this, it is possible to efficiently introduce anisotropy to the coating film.

For the coating film used in the present invention, high-efficiency introduction of anisotropy, the most appropriate amount of polarized ultraviolet radiation, should be the most appropriate for the photo-crosslinking reaction or photoisomerization reaction, or phototransaction of the photosensitive base in the coating film. -The amount of polarized ultraviolet radiation that corresponds to the amount of Fleis rearrangement reaction. To the present invention As a result of the coating film being irradiated with polarized ultraviolet rays, the photosensitive group of the side chain that undergoes a photocrosslinking reaction, a photoisomerization reaction, or a photo-Fries rearrangement reaction is small, and a sufficient amount of photoreaction cannot be obtained. At this time, the self-organization is not sufficiently self-organized even after heating. On the other hand, in the coating film used in the present invention, as a result of irradiating a structure having a photocrosslinkable group with polarized ultraviolet rays, an excessive amount of the photosensitive group of the side chain undergoing the crosslinking reaction will cause the crosslinking reaction between the side chains to proceed excessively. . At this time, the obtained film becomes rigid, and the progress of self-organization may be hindered by subsequent heating. In addition, in the coating film used in the present invention, as a result of irradiating a structure having a photo-Fries rearrangement group with polarized ultraviolet rays, an excess of the photosensitive group of the side chain undergoing the photo-Fries rearrangement reaction results in an excessive amount of the coating film The liquid crystallinity becomes too low. At this time, the liquid crystallinity of the obtained film is also reduced, and subsequent heating may hinder the progress of self-organization. Furthermore, when polarized ultraviolet rays are irradiated to a structure having a photo-Fries rearrangement group, if the amount of ultraviolet rays is too large, the side chain polymer undergoes photolysis, which may hinder self-organization due to subsequent heating.

Therefore, in the coating film used in the present invention, the photosensitive group of the side chain undergoes a photocrosslinking reaction, a photoisomerization reaction, or a photo-Fries rearrangement reaction by irradiation of polarized ultraviolet rays. 0.1 mol%-40 mol% of the photosensitive group of the side chain type polymer film is preferably 0.1 mol%-20 mol%. By setting the amount of the photosensitive group of the side chain that undergoes the photoreaction in such a range, the self-organization in the subsequent heat treatment can be efficiently performed, and highly efficient anisotropy can be formed in the film.

In the coating film used in the method of the present invention, by optimizing the irradiation amount of polarized ultraviolet light, the side chain of the side chain type polymer film has a feeling of The amount of the photocrosslinking reaction, photoisomerization reaction, or photo-Fries rearrangement reaction of the photoactive group is optimized. However, in conjunction with the subsequent heat treatment, it is possible to efficiently introduce anisotropy to the coating film used in the present invention. At this time, the amount of preferable polarized ultraviolet light can be evaluated based on the ultraviolet absorption of the coating film used in the present invention.

That is, for the coating film used in the present invention, the ultraviolet absorption in the direction parallel to the polarization direction of the polarized ultraviolet rays and the ultraviolet absorption in the perpendicular direction after the polarized ultraviolet rays are respectively measured. From the measurement result of the ultraviolet absorption, the difference ΔA between the ultraviolet absorbance in the direction parallel to the polarization direction of the polarized ultraviolet rays and the ultraviolet absorbance in the vertical direction in the coating film was evaluated. In the coating film used in the present invention, the maximum value of ΔA (ΔAmax) achieved and the irradiation amount of polarized ultraviolet rays to achieve it were determined. In the manufacturing method of the present invention, based on the amount of polarized ultraviolet irradiation that achieves the ΔAmax, the optimal amount of polarized ultraviolet irradiation in the manufacture of the liquid crystal alignment film can be determined.

In the manufacturing method of the present invention, the amount of polarized ultraviolet light used in the present invention to irradiate the coating film is preferably within the range of 1% to 70% of the amount of polarized ultraviolet light used to achieve ΔAmax, and more preferably within the range of 1% to 50%. good. In the coating film used in the present invention, the irradiation amount of polarized ultraviolet light in the range of 1% to 50% of the amount of polarized ultraviolet light that achieves ΔAmax is equivalent to 0.1 mol of the total photosensitive group that the side chain polymer film has %~20mol% enters the amount of polarized ultraviolet light that forms the photocrosslinking reaction.

From the above, in the manufacturing method of the present invention, because the introduction of anisotropic properties to the coating film is realized with high efficiency, the liquid crystal of the side chain type polymer The temperature range is the reference, and it is appropriate to determine the above-mentioned generally preferable heating temperature. Therefore, for example, when the liquid crystal temperature range of the side chain polymer used in the present invention is 100°C to 200°C, the heating temperature after polarized ultraviolet radiation is preferably 90°C to 190°C. By this, the coating film used in the present invention is given greater anisotropy.

With this, the liquid crystal display element provided by the present invention exhibits high reliability against external pressure such as light or heat.

As described above, the substrate for a horizontal electric field drive type liquid crystal display element manufactured by the method of the present invention or a horizontal electric field drive type liquid crystal display element having the substrate is excellent in reliability and can be suitably used for large-screen and high-definition liquid crystal televisions, etc. .

The following examples illustrate the present invention, but the present invention is not limited to this embodiment.

[Example]

The abbreviations used in the examples are as follows.

<Methacrylic monomer>

<Liquid Crystal Compound>

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

PLC1 purchased commercially available products for use.

Commercially available LC242 (BASF Corporation) was used for PLC2.

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

PLC5 is a novel compound that is not disclosed in the literature. Although PLC5 was synthesized using PLC4 and PLC5-1, its details are described in the following "<Synthesis of Compound PLC5>". In addition, PLC5-1 was synthesized by the synthesis method described in the literature (Liquid Crystals (2005), 32(8), 1031-1044.).

PLC6 uses commercially available M6BC (manufactured by Green Chemical Co., Ltd.).

<Synthesis of compound PLC5>

In a 500mL four-necked flask, add compound PLC4 (20.00g, 65.3mmol), compound PLC5-1 (14.09g, 71.8mmol), EDC (15.02g, 78.4mmol), DMAP (0.80g, 6.53mmol), THF (200g ), the reaction was carried out at 23°C. Reaction tracking was performed by HPLC, and after confirming that the reaction was completed, the reaction solution was poured into distilled water (1.2 L), ethyl acetate (2 L) was added, and the water layer was removed by a liquid separation operation. After the organic layer was washed with distilled water (500 mL) three times, the organic layer was dried with magnesium sulfate. After that, it was filtered and the solvent was distilled off with an evaporator to obtain compound PLC5-2 as an oily compound. Next, pyridinium p-toluenesulfonic acid (referred to as PPTS) (1.59 g, 6.3 mmol) and ethanol (100 g) were added to the obtained compound PLC5-2, and the mixture was heated and stirred at 60°C. The reaction was followed by HPLC, and after confirming that the reaction was completed, the reaction solution was cooled in an ice bath, and the precipitated solid was filtered and washed with ethanol. By making The obtained solid was dried under reduced pressure to obtain PLC5 of 19.2 g of compound (yield 69%).

¹ H-NMR (400MHz, CDCl3, δppm): 8.22-8.18 (2H, m), 8.17-8.14 (2H, m), 7.36-7.32 (2H, m), 7.00-6.96 (2H, m), 6.12 6.11 (1H, m), 5.57-5.55 (1H, m), 4.20-4.16 (2H, m), 4.06 (2H, t), 1.96-1.95 (3H, m), 1.90-1.46 (8H, m).

In addition, the molecular weight measurement conditions of the resin are as follows.

Device: Room temperature colloidal permeation chromatography (GPC) device (SSC-7200) manufactured by Quanzhou Science Company, column: column (KD-803, KD-805) manufactured by Shodex Company, column temperature: 50°C, lysate: N,N'-dimethylformamide (as an additive, lithium bromide-hydrate (LiBr. H ₂ O) is 30mmol/L, phosphoric acid. Anhydrous crystals (o-phosphoric acid) is 30mmol/L, tetrahydrofuran (THF) is 10ml/L), flow rate: 1.0ml/min, calibration line preparation standard sample: Tosoh Corporation TSK standard polyethylene oxide (molecular weight approximately 9000,000, 150,000, 100,000, 30,000), and Polymer Laboratories Ltd. Production of polyethylene glycol (molecular weight of about 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 after nitrogen substitution was performed, AIBN (0.25 g, 1.5 mmol) was added, followed by degassing and nitrogen substitution. Then, the reaction was carried out at 60°C for 24 hours to obtain a polymer solution of methacrylate. The polymer solution was dropped to diethyl ether (5000 ml), and the obtained precipitate was filtered. This deposit 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 the mixture was stirred and dissolved at room temperature for 5 hours. BCS (30.0g) was added to this solution, and it stirred at room temperature for 5 hours, and obtained the liquid crystal alignment agent B1.

<Example 1>

With respect to 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.04 g (relative solid content of 10% by mass) of the liquid crystal compound PLC1 obtained in Synthesis Example 1 was added, and stirred at room temperature for 3 hours to dissolve to prepare the liquid crystal alignment agent B2.

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

<Example 2>

With respect to 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.10 g of the liquid crystal compound PLC1 obtained in Synthesis Example 1 (relative solid content 25% by mass) was added, and stirred at room temperature for 3 hours to dissolve to prepare a liquid crystal alignment agent B3.

The obtained liquid crystal alignment agent B3 was stored in the freezer for 1 day, and after thawing, no precipitate was confirmed.

<Example 3>

With respect to 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.10 g of the liquid crystal compound PLC2 obtained in Synthesis Example 1 (relative solid content 25% by mass) was added, and stirred at room temperature for 3 hours to dissolve to prepare the liquid crystal alignment agent B4.

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

<Comparative Example 1>

With respect to 10.0 g of the liquid crystal alignment agent D1 obtained in Synthesis Example 1, 0.10 g of the liquid crystal compound PLC3 obtained in Synthesis Example 1 (relative solid content 25% by mass) was added, and stirred at room temperature for 3 hours to dissolve to prepare a liquid crystal alignment agent B5.

The obtained liquid crystal alignment agent B5 was stored in the freezer for one day, and after thawing, no precipitate was confirmed.

<Comparative Example 2>

With respect to 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.10 g of the liquid crystal compound PLC4 obtained in Synthesis Example 1 (relative solid content 25% by mass) was added, and stirred at room temperature for 3 hours to dissolve to prepare the liquid crystal alignment agent B6.

The obtained liquid crystal alignment agent B6 was stored in the freezer for one day, and after thawing, no precipitate was confirmed.

<Comparative Example 3>

With respect to 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.10 g of the liquid crystal compound PLC5 obtained in Synthesis Example 1 (relative solid content 25% by mass) was added, and stirred at room temperature for 3 hours to dissolve the liquid crystal alignment agent. B7.

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

<Comparative Example 4>

With respect to 10.0 g of the liquid crystal alignment agent B1 obtained in Synthesis Example 1, 0.10 g of the liquid crystal compound PLC6 obtained in Synthesis Example 1 (relative solid content 25% by mass) was added, and stirred at room temperature for 3 hours to dissolve to prepare the liquid crystal alignment agent B8.

The obtained liquid crystal alignment agent B8 was stored in the freezer for 1 day, and after thawing, no precipitate was confirmed.

<Example 4> [Production of liquid crystal cell]

Using the liquid crystal alignment agent B3 obtained in Example 1, the twisted nematic liquid crystal cell was produced by the following procedure.

The liquid crystal alignment agent B3 obtained in Example 1 was spin-coated on the ITO surface of the ITO electrode substrate formed with the ITO electrode pattern, and dried on a heating plate at 70°C for 90 seconds, and then the substrate was irradiated with an inclined angle of 40 from the horizontal direction. ° 313nm polarized ultraviolet light 50mJ/cm ² , heated on a heating plate at 200°C for 10 minutes to form a liquid crystal alignment film with a film thickness of 100nm. Regarding the above two substrates, spacer beads of 6 μm were spread on the liquid crystal alignment film of one substrate, and then a sealant (solvent-type thermosetting epoxy resin) was printed thereon. Then, after bonding the two substrates in a straight alignment direction, the sealant is hardened to produce an empty cell. Liquid crystal MLC-2003 (C080) (trade name of Merck & Co.) was injected into this empty cell by a reduced pressure injection method to produce a twisted nematic liquid crystal cell. The fabricated liquid crystal cell was then placed in a hot-air circulating oven at 120°C for 1 hour to perform the realignment treatment of the liquid crystal.

<Example 5>

A twisted nematic liquid crystal cell was produced in the same manner as in Example 4 except that the angle of the polarized ultraviolet light was 30°.

<Example 6>

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

<Example 7>

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

<Example 8>

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

<Example 9>

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

<Example 10>

In addition to replacing the liquid crystal aligning agent B3, using the liquid crystal aligning agent B2, and In the same manner as in Example 6, a twisted nematic liquid crystal cell was produced.

<Comparative Example 5>

Except for replacing the liquid crystal alignment agent B3 of Example 4 and using the liquid crystal alignment agent B1, in the same manner as in Example 4, a twisted nematic liquid crystal cell was produced.

<Comparative Example 6>

Except for replacing the liquid crystal aligning agent B3 and using the liquid crystal aligning agent B1, in the same manner as in Example 6, a twisted nematic liquid crystal cell was produced.

<Comparative Examples 7-10>

Except for replacing the liquid crystal alignment agent B3 and using the respective liquid crystal alignment agents B5 to B8, in the same manner as in Example 6, a twisted nematic liquid crystal cell was produced.

(Determination of pretilt angle)

The pretilt angle (°) of the twisted nematic liquid crystal cell was measured using the "Axo Scan" manufactured by Axo Metrix Corporation, using the Muller matrix method.

The results are shown in Table 1 below.

As shown in Table 1, in Examples 4 to 10 in which the reactive mesogen compound of component (B) was added, the obtained liquid crystal alignment film showed a pretilt angle suitable for twisted nematic mode. On the other hand, in Comparative Examples 5 and 6 using the liquid crystal alignment agent of the reactive mesogen compound without adding the component (B), the pretilt angle is 50° to 58°, which cannot be the pretilt angle suitable for the twisted nematic mode . In addition, in Comparative Examples 7 to 10, which are examples of adding compounds other than mesogen compounds, the pretilt angle is 0°.

As described above, in the embodiment of the present invention, the alignment film encapsulating the liquid crystal compound is irradiated with ultraviolet rays in an oblique direction to exhibit any pretilt angle. Can provide liquid crystal alignment film suitable for twisted nematic mode.

<Example 11>

After the liquid crystal cell was produced in the same manner as in Example 6, UV5 J/cm ² passing through a 365 nm band pass filter was irradiated from the outside of the liquid crystal cell.

(Voltage Holding Rate (VHR) Evaluation)

The evaluation of VHR is based on applying a 5V voltage to the obtained liquid crystal cell at a temperature of 60° C. for 60 μs, and measuring the holding voltage of the liquid crystal cell after 16.67 ms.

The results are shown in Table 2 below.

As shown in Table 2, in Example 11 of the present invention, by irradiating ultraviolet rays of 365 nm, the liquid crystal compound is polymerized in the liquid crystal cell, and the voltage holding ratio is improved, so that a liquid crystal display device with excellent long-term reliability can be provided.

Claims (10)

A polymer composition characterized by containing (A) a photosensitive side chain polymer (B) a reactive mesogen compound that exhibits liquid crystallinity in the temperature range of 100°C to 300°C, and (C) an organic solvent, (A) ) Component has any one photosensitive side chain selected from the group consisting of the following formulas (1) to (6),

[In the formula, A, B, and D are independent of each other and are single bonds, -O-, -CH ₂ -, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO- O-, or -O-CO-CH=CH-; S is an alkylene group with 1 to 12 carbons, and the hydrogen atoms bonded to them can be substituted by halogen groups; T is a single bond or 1 to 12 carbons And the hydrogen atoms bonded to them can be substituted by halogen groups; Y ₁ is a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring and an alicyclic ring with 5 to 8 carbon atoms The ring selected by the hydrocarbon, or the same or different 2-6 rings selected by their substituents, are bonded through the bonding group B, and the hydrogen atoms bonded to them are independent, and can be By -COOR ₀ (where R ₀ is an alkyl group with carbon number 1 to 5), -NO ₂ , -CN, -CH=C(CN) ₂ , -CH=CH-CN, halogen group, carbon number 1 Alkyl group of ~5, or alkyloxy group of carbon number 1~5; Y _{2 is a} bivalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, alicyclic ring of carbon number 5~8 Hydrocarbons, and groups selected from the group formed by their combination, and the hydrogen atoms bonded to them are independent of each other, and can be replaced by -NO ₂ , -CN, -CH=C(CN) ₂ , -CH=CH- CN, halogen group, alkyl group with 1 to 5 carbons, or alkyloxy group with 1 to 5 carbons; R is alkoxy with 1 to 6 carbons, or _{synonymous with Y 1} ; Cou is coumarin -6-group or coumarin-7-group, the hydrogen atoms bonded to them are independent of each other, can be -NO ₂ , -CN, -CH=C(CN) ₂ , -CH=CH-CN, halogen Group, an alkyl group with 1 to 5 carbons, or an alkyloxy group with 1 to 5 carbons; one of q1 and q2 is 1 and the other is 0; q3 is 0 or 1; X is a single bond, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CH=CH-CO-O-, or -O-CO-CH=CH-, the number of X When it is 2, X may be the same or different from each other; P and Q are independent of each other and are a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon with 5 to 8 carbon atoms, and The group selected from the group formed by their combination; but, when X is -CH=CH-CO-O-, -O-CO-CH=CH-, -CH=CH- P or Q on the bonding side Is an aromatic ring; l1 is 0 or 1; l2 is an integer from 0 to 2; when both l1 and l2 are 0, when T is a single bond, A is also a single bond; when l1 is 1, when T is a single bond, B is also Single bond; H and I are independent of each other and are groups selected from a combination of divalent benzene ring, naphthalene ring, biphenyl ring, furan ring, pyrrole ring, and their combination] The reactive mesogen compound of component (B) is as follows The compound represented by formula (I), P-Sp-X-MG-X-Sp-P (I) [In formula (I), P is a polymerizable group, and Sp is a spacer with 1-20 carbon atoms , X is selected from -O-, -S-, -CO-, -COO-, -OCO-, -OCO-O- A group or a single bond, MG is a mesogen group or a mesogen support group, and the group 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 independent of each other and are 1,4-phenylene groups, and one or more of the CH groups present in this group may be substituted by N again, or 1 ,4-cyclohexylene, and one CH ₂ group or two non-adjacent CH ₂ groups in the group can be substituted by O and (or) S, or 1,4-cyclohexenylene Or naphthalene-2,6-diyl, and all of these groups are unsubstituted, or can be substituted by one or more halogen, cyano or nitro groups, or alkyl or alkoxy groups with 1-7 carbon atoms Group or alkane group, one or more of the H atoms in these groups can be substituted by F or Cl, Z ¹ and Z ² are independent of each other and are -COO-, -OCO-, -CH ₂ CH ₂ -, -OCH ₂ -, -CH ₂ O-, -CH=CH-, -CC=, -CH=CH-COO-, -OCO-CH=CH- or single bond, and m is 0, 1 or 2)]. The polymer composition according to claim 1, wherein the component (A) has the following formulas (21) to (31) [wherein A and B have the same definitions as above; where A, B, R , Q1 and q2 have the same definitions as above; Y ₃ is a monovalent benzene ring, naphthalene ring, biphenyl ring, furan ring, nitrogen-containing heterocyclic ring, and alicyclic hydrocarbon with carbon number 5 to 8, and their combination The groups selected from the group, and the hydrogen atoms bonded to them are independent of each other, and can be replaced by -NO ₂ , -CN, halogen groups, alkyl groups with 1 to 5 carbons, or alkanes with 1 to 5 carbons. Substituted by oxy; R ₃ is a hydrogen atom, -NO ₂ , -CN, -CH=C(CN) ₂ , -CH=CH-CN, halogen group, monovalent benzene ring, naphthalene ring, biphenyl ring, furan Ring, nitrogen-containing heterocycle, alicyclic hydrocarbon with 5 to 8 carbons, alkyl with 1 to 12 carbons, or alkoxy with 1 to 12 carbons; l is an integer from 1 to 12, and m is 0 to However, in formulas (23) to (26), the total of all m is 2 or more, and m1, m2, and m3 are each independently an integer of 1 to 3; R ₂ is a hydrogen atom, -NO ₂ , -CN, a halogen group, a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a nitrogen-containing heterocyclic ring, and an alicyclic hydrocarbon with 5 to 8 carbon atoms, and an alkyl group or an alkyloxy group; Z ₁₁ , Z ₁₂ is a single bond, -CO-, -CH ₂ O-, -CH=N-, -CF ₂ -] any one liquid crystal side chain selected from the group consisting of,

A method for manufacturing a substrate with a liquid crystal alignment film, which is characterized It is a step of forming a coating film by applying the composition described in claim 1 or 2 on a substrate with electrodes for liquid crystal driving by having [I]; [II] The coating film obtained by [I] is irradiated from an oblique direction The step of polarizing ultraviolet rays; and [III] the step of heating the coating film obtained in [II]; to obtain a liquid crystal alignment film endowed with alignment control capabilities. A substrate with a liquid crystal alignment film characterized by being manufactured by the method described in claim 3. A vertical electric field drive type liquid crystal display element characterized by having the substrate described in claim 4. A twisted nematic liquid crystal display element or OCB liquid crystal display element characterized by having the substrate described in claim 4. A method for manufacturing a vertical electric field drive type liquid crystal display element, characterized by having the following steps to obtain a vertical electric field drive type liquid crystal display element, the step of preparing the substrate (first substrate) described in claim 4; Steps [I] to [III] described in Item 3 to obtain the second substrate; and [IV] The first and second substrates are arranged facing each other with the liquid crystal alignment films of the first and second substrates facing each other through the liquid crystal. Step of obtaining a liquid crystal display element by 2 substrates. A method for manufacturing a twisted nematic liquid crystal display element, which is characterized by having the steps in the method described in claim 7, and the [IV] step In this, the first and second substrates are arranged so that the alignment directions are perpendicular to each other and are opposed to each other. A vertical electric field drive type liquid crystal display element characterized by being manufactured by the method described in claim 7. A twisted nematic liquid crystal display element characterized by being manufactured by the method described in claim 8.