JPS6315223A - Coating liquid for liquid crystal orientation film and liquid crystal orientation film formed by heating - Google Patents

Abstract

PURPOSE:To eliminate the need for a pretreatment of a glass substrate by incorporating a soluble polyimide siloxane precursor obtd. by mixing a tetracarboxylic dianhydride, diamine and aminosilicone compd. in a solvent, adding a silicone compd. thereto at need and bringing the mixture into heating reaction into the titled coating liquid. CONSTITUTION:This coating liquid contains the soluble polyimide siloxane precursor obtd. by mixing the tetracarboxylic dianhydride expressed by formula I, the diamine expressed by formula II and the aminosilicone compd. expressed by formula III in the solvent, bringing the mixture into reaction, adding the silicone compd. expressed by formula IV thereto at need and optionally bringing the same into the heating reaction. In formula R<1> denotes a tetravalent carbocyclic arom. group, R<2> denotes a straight chain or branched aliphat. group, etc., of 2-50C, R<3> denotes -(CH2)8-, etc., R<4> independently denotes an alkyl group of 1-20C, phenyl group, etc., R<5> independently denotes X<2>, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a super twist birefringence effect type liquid crystal alignment film coating solution and a super twist birefringence effect type coating solution formed by heating the same. The present invention relates to a liquid crystal alignment film.

[Conventional technology]

(hereinafter sometimes referred to as the TN method) is the mainstream, so a film for horizontal alignment is mainly used.

The horizontal alignment film is created by coating the glass substrate with polyvinyl alcohol, Teflon, etc. from the initial inorganic alignment film made of StO, etc., on a glass substrate by vacuum evaporation, and wrapping the formed film with cloth, etc. This has led to the transition to organic polymer films that orient liquid crystals.

The first reason for this is workability.In the case of an inorganic alignment film, only a limited number of glass substrates can be processed in a vacuum chamber, whereas in the case of an organic alignment film, it is possible to process only a limited number of glass substrates in a vacuum chamber. This is because the number of films that can be processed is several tens of times larger than that of an inorganic alignment film.

Second, with inorganic alignment films, it is extremely difficult to maintain constant quality by strictly controlling the degree of vacuum in the vacuum chamber and the conditions during vapor deposition, but with organic polymer films, it is relatively easy to control the conditions. This is because the quality is easily kept constant.

Currently, polyimide films, which are excellent in moisture absorption resistance, are mainly used as organic polymer films. However, the currently used polyimide has poor adhesion to glass substrates, so sufficient adhesion cannot be obtained unless the polyimide is applied after treating the glass substrate with a silane coupling agent.

Here, one of the H9 factors for the alignment film for the TN system is the pre-tilt angle.

This is the angle that the liquid crystal molecules make with the glass substrate when nematic liquid crystal is injected into the cell and no voltage is applied. It can be said that the smaller this pre-tilt angle is, the more suitable it is for making the screen larger. Currently, liquid crystal display elements are rapidly progressing toward larger screens, but the conventional TN method has already reached its limit for larger screens, and several new methods have been devised as a solution. .

One of them is the super twist birefringence effect method (hereinafter S
(sometimes called the BE method).

This is because, while the TN system twists the liquid crystal molecules 90 degrees and arranges them within the cell, the liquid crystal molecules are arranged with a twist of 200 to 270 degrees.
) and viewing angle dependence (*2) are greatly improved.

(*1) The brightness ratio between the black display part to which voltage is applied and the white part of the background. The larger this ratio is, the more the display appears to be distorted.

(*2)! The contrast ratio changes depending on the direction in which the image is viewed, so the smaller the dependence, the better.

However, with this SBE method, the stable 200-2704
In order to obtain the &L twist, unlike the 1jTN method, pre-
It is desirable that the tilt angle is 6 degrees to 30 degrees. In this case, the term tilted orientation is used. Tilted orientation means that the pre-tilt angle is larger than 0 degrees to a certain extent and smaller than 90 degrees to a certain extent. If I had to say it, it would be about 5.
~80 degrees. An inorganic alignment film is used to obtain this tilted alignment. This is because by changing the angle of vacuum deposition, the pre-tilt angle can be controlled to a desired angle.

[Problem that the invention seeks to solve]

Conventionally, inorganic alignment films have been used to obtain tilted alignment, but organic polymer films are superior in terms of workability and uniformity of quality. It is preferable that . However, until now, organic polymer membranes have only been able to achieve complete duty alignment or a pre-tilt angle close to 0 degrees. Furthermore, since conventional organic polymer films have poor adhesion to glass substrates, pretreatment with a silane coupling agent is required.

[Means for solving problems]

The present invention is a means for solving the problems of the prior art described above and satisfying the above needs.

A tetracarboxylic dianhydride represented by the following formula (1), a diamine represented by the formula (2), and an aminosilicon compound represented by the formula (3) are mixed in a solvent and reacted, and if necessary, the formula ( This is a coating liquid for a liquid crystal aligning film characterized by containing a soluble polyimidonoroxane precursor obtained by adding the silicon compound represented by 4) and optionally performing a heating reaction.

Nl2- R2-Nl2 ・・・・・・・・・
...(2) Nl2-R3-3iR43,X-...
...(3) si(R5)3x2 ...
・・・・・・・・・(4) [In formulas (1) to (4)
Hl represents a tetravalent carbocyclic aromatic or branched aliphatic group having 6 to 50 carbon atoms, where 8 represents an integer of 1 to 4; )
, R4 independently represents an alkyl group having 1 to 20 carbon atoms, a phenyl group, or an alkyl-substituted phenyl group,
and X2 independently represent an alkoxy group, an acetoxy group, or a halogen/i hydroxyl group, and R5 independently represents R4, X2 or the following formula (6), where l takes a value of l≦l≦100. ) All of R5 will not become R4 at the same time,
m takes a value of 1≦m<3.

H4n 4 Note that groups or alphabetic characters with the same symbol independently represent groups or numbers within a predetermined range even if the general formulas containing them are different. Same below. ] Second, apply the solution on a glass substrate and apply it to
It is a liquid crystal aligning film formed by evaporating the solvent by heating to °C, crosslinking the precursor, and curing it.

The raw materials of the present invention will be explained.

Examples of the tetracarboxylic dianhydride represented by formula (1) include the following compounds.

Pyromellitic dianhydride, 3.3', 4.4'-biphenyltetracarboxylic dianhydride, 2.2', 3.3'
-Biphenyltetracarboxylic dianhydride, 2,3.3
'.

4'-biphenyltetracarboxylic acid dimhydrate, 3°3'
, 4.4'-benzophenonetetracarboxylic dianhydride, 2,3.3',4'-benzophenonetetracarboxylic dianhydride, 2.2',3.3-benzophenonetetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl)-ether dianhydride, his(3,4-dicarboxyphenyl)-sulfone dianhydride, 1,2,5.6-naphthalenetetracarboxylic dianhydride, 2,3,6 .7-
Naphthalene tetracarboxylic dianhydride, etc.

Moreover, the following compounds can be mentioned as specific examples of the diamine represented by formula (2).

1,3-diaminopropane, 2,2-dimethyl-1゜3
-Diaminopropane, 2,2-cyhexyl-1°3-diaminopropane, 2,2-dioctadecyl-1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminobutantane, 1,6- These include aliphatic diamines such as diamithexane, aromatic aliphatic diamines such as 2,2-(4,4'-diaminodiphenyl)propane, and diamines of polysiloxanes represented by the following formulas.

CH30H.

C6''13 06H13 H3CH3 Next, the following compounds can be mentioned as aminosilicon compounds represented by formula (3).

NF2 (CH2)3 Si (OCH3)3, N
F2-(c)I2)3-si(OC2H5)3,N
F2 (CH2)3 5i (CHs) (OCH3)z
, NF2 (CH2)3 81 (CH3) (OC
2H5)2, NF2 (CH2)3 5l(C2H5
)(On C3117)2, NF2 (CH2)4-
8i (OCH3)3, NF2 (CH2)4 81(
OC2H5)3, NF2 (CH2)4 5t(CH
3) (OC2Hs)z, NF2-○-8i (OC2H
5) As the silicon compound represented by 3 and formula (4), the following compounds can be mentioned.

S i (OCH3)4 , S i (CH3) (O
CH3)3,"'(C6H13)(OCH3)3,S
1 (CtsH37) (OCH3) 3.5t (CH3
)2(OCH3)2, St(CH3)(C1gH3-
) (OCH3) 2.5i (OC2H5 people, 31 (CI
(3) (OC2H5), 5i (C6H13) (OC2
H5) 3.5i (C1aH37) (OC2H5) 3.5
l(CHs)z (OC2”5)2, CH5CH3CH
3 CHCH,CH3 CM3CH,CH3 In the method of the present invention, the above raw material compound is I! N-methyl-2-pyrrolidone, N,N
-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, tetramethylurea, pyridino, dimethylsulfone, hexamethylphosphoramide,
Methylformamide, N-acetel-2-pyrrolidone,
One or more of toluene, xylene, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol motsubutyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, cyclopentanone, cyclohexanone, etc. can be used. Heavy! It can also be used as a mixed solvent with other solvents containing at least 100% of the solvent.

Next, the reaction method will be explained. A tetracarboxylic dianhydride represented by formula (1), a diamine represented by formula (2), and an aminosilicon compound represented by formula (3) are reacted in a reaction solvent.

The reaction solvent is preferably used in an amount of 40% by weight or more based on the total weight of the reaction solvent and the added raw materials. If it is less than this, the stirring operation may be difficult.

This first stage reaction is preferably carried out at a temperature of 0°C or higher and 200°C or lower.

Reaction time a　O, preferably 2 to 20 hours.

When the reaction temperature is relatively high, for example 60 to 200°C, the siloxane combination reaction proceeds simultaneously with the imidization reaction, as will be described later, and the liquid may lose fluidity due to the gelation reaction.

To avoid this phenomenon, a small amount of (CH3)3St (
The reaction can also be carried out by adding a silylating agent such as OCH3) or (CH3)3Si('C2H3).

The mixing ratio of acid and amine is as follows: the amount of acid anhydride represented by formula (1) is λ mole, the amount of diamine represented by formula (2) is B mole, and the amount of aminosilicon compound represented by formula (3) is If it is C mole, the deviation on both sides is ±20 from 2A=2B+C
% or less is particularly preferable.

When the diamine represented by formula (2) does not contain silicon, the ratio of the amino silicon compound represented by formula (3) to it is particularly preferably within the range of formula (7).

□≧0.1 (7) B+C Regarding the layer thickness of the reaction raw materials added to the reaction system, all of the tetracarboxylic dianhydride, diamine, and aminosilicon compound are added to the reaction solvent at the same time. They may be reacted in addition, or the former two may be reacted in advance and then the reaction product may be reacted with the aminosilicon compound. If the amino silicon compound is added last, it is easier to obtain a polymer with a higher molecular weight.

Furthermore, if necessary, the silicon compound represented by formula (4) can be used as it is added to the first stage reaction solution,
It is also possible to carry out this mixing reaction for 60-22.003;0 hours. In this case, it is also possible to add a silylating agent to prevent gelation of the reaction solution, and a silylating agent such as rounded triethylamine to advance the siloxane condensation reaction.
It is also possible to add a grade amine or an acid catalyst such as acetic acid, and addition of a small amount of water may also contribute to promoting the reaction.

The effect of adding the compound of formula (4) is to increase the adhesive effect when the coating solution of the present invention is applied to a glass substrate and fired, and also to increase or decrease the amount of addition of the compound of formula (1), (2L (
It is possible to increase or decrease the pre-tilt angle of the polyimide alignment film formed from the compound of 3), thereby making it possible to obtain a desired pre-tilt angle.

As mentioned above, any of the first-stage reaction solution, a mixture of this and the silicon compound of formula (4), or a second-stage reaction solution obtained by reacting this mixture can be used as the coating solution of the present invention. However, it is also possible to use a solution of a mixture of any of these with other compounds, such as a conventional wholly aromatic polyamic acid (added to adjust the pretilt angle).

The coating solution containing the soluble polyimidosilochitin precursor thus obtained is applied by a known method such as spinner, dipping, printing, etc., and the solvent is evaporated by heating to 100 to 300°C. The precursor can be crosslinked and cured.

〔Effect of the invention〕

The coating solution containing the soluble polyimide siloxane precursor produced by the method of the present invention is coated onto a glass substrate by an appropriate method and then baked to complete the imidization reaction and progress the formation of siloxane bonds, resulting in a hard and tough coating. It forms a strong bond to the glass substrate.

Therefore, the glass substrate must be pre-treated with a silane coupling agent, which was necessary with conventional polyimide films.

Reasoning is no longer necessary. Furthermore, it can be easily obtained by rubbing a stable R-shaped film.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples, Comparative Examples, and Usage Tests.

Example 1 Eleven flasks equipped with a stirring device, a dropping funnel, a thermometer, a condenser, and a nitrogen purging device were fixed in a constant temperature bath. After purging the inside of the flask with nitrogen gas, 500jdD2-butoxyshetanol was dehydrated and purified, 16.
Number average molecular weight of 98 F (60166 mol) 1020
After adding (3-aminopropyl)polydimethylsiloxa/ (7=11.4 in formula (5)) at both ends, 4.84f (0,02
After adding 22 mol) of pyromellitic dianhydride and carrying out the reaction at this temperature for 3 hours, 1.90 f (0,0098
mol) of 3-7 minopropyldethoxysilane was added, and the reaction was further carried out at 25 to 30°C for 3 hours to obtain a transparent liquid (pheno). The rotational viscosity of the obtained coating liquid of the present invention at 25° C. was 25 centipoise.

The rotational viscosity was measured at a temperature of 25±0.1° C. using an EW viscometer manufactured by Tokyo Keiki@.

Same below.

This coating solution was filtered through a 0.2μ filter to prepare a sample, and then coated uniformly onto a glass substrate using a spinner. This was heated at 200° C. while open to evaporate the solvent and harden it. The surface of the resulting coating film was smooth and adhered strongly to the glass substrate, and no peeling of the coating film occurred in the following adhesion test.

The adhesion test was carried out as follows: A cut was made in the 111 film on the knee glass substrate, and a square 10 with side 2n was cut.
It was divided into 0 small pieces, and cello tape was applied to the surface of the piece and immediately removed.

Adhesion was evaluated by counting the number of peeled sheets.

Example 2 Octyltriethoxysilane and 2-butoxyshetanol, which is a solvent, were added to a part of the pheno obtained in Example 1, and the total amount of solid content and octyltriethoxysilane in the pheno was added. The ratio of octyltriethoxysilane was adjusted to 30% by weight, and the total amount of solid content in the face and octyltriethoxysilane was adjusted to 5% by weight based on the total mixed liquid. This mixed solution was reacted at 100° C. for 3 hours to obtain a coating solution of the present invention. The rotational viscosity of this coating liquid at 25°C is 31 centipoise.

This was purified, coated and cured in the same manner as in Example 1. The surface of the obtained coating film was smooth, and there was no peeling of the coating film in the adhesion test mentioned above.
-methoxyethanol, 5.96 f (0,0584
mol) of 2,2-dimethyl-1,3-diaminopropane, 4.03F (0.0211 mol) of 3-aminopropylmethyljethoxysilane and 15,292 (0.070 mol) of 3-aminopropylmethyljethoxysilane.
mol) of Ilff dianhydride was added and the
The reaction was carried out at 25°C for 3 hours and then at 55-60°C for 1 hour to obtain a homogeneous liquid containing a polyimidosiloxane precursor. A portion of this reaction product solution was taken and octadecyltriethoxysilane and 2-methoxyethanol were added to it.
The compositions shown in the table were prepared and each solution was reacted at 120° C. for 8 hours to obtain a coating solution of the present invention.

Each coating solution was prepared into f# in the same manner as in Example 1, and then applied onto a glass substrate using a spinner, and baked at 200° C. for 1 hour to harden.

The surface of each coating film was smooth and adhered strongly to the glass substrate, and no peeling of the coating film occurred in the adhesion test.

Table 1 However, 0DSE is octadecyltriethoxysilane, and the solid content refers to what is solid when the polyimide silochitin precursor solution in the previous step is fired at 200'C.

Same below.

Example 7 2 of 500IIl was prepared using the same apparatus and method as in Example 1.
-methoxyethanol, 2,451' (0,0200 mol) of 2,2-dimethyl-1,5-diaminopentane,
6.78y (0,0133 mol) at both ends (3-aminopropyl)polydimethylsiloxane (formula (s)).

l = 4.50) and 12.9or (0,0400
3.3' of mole).

4. After adding 4'-be/siphenotetracarboxylic dianhydride and carrying out a reaction at 25 to 30°C for 2 hours, 2.
94f (0,0133 mol) of 3-aminopropyltriethoxine was added, and the reaction was carried out at 55 to 60°C for 1 hour to obtain a homogeneous solution. Part of this reaction product liquid was mixed with Kn-octyltriethoxysilane and 2-methoxyethanol, so that the weight of the solid content in the reaction liquid in the previous step was equal to the weight of n-octyltriethoxysilane, and The total amount of both is 51 of the total solution! A coating solution of the present invention was prepared in a proportion of . The rotational viscosity of this coating liquid at 25°C is Fi4.
37 inches bois.

This coating liquid was applied onto a glass substrate using a spinner, and then baked at 200° C. for 1 hour to harden it. The surface of this coating film was smooth and firmly adhered to the glass substrate, and no peeling of the coating film occurred in the adhesion test.

Comparative Example 1 500d N-methyl-2-pyrrolidone and 12.97F (0,0f548
mol) of 4,4'-diaminodiphenyl ether and 1
A transparent liquid was obtained by adding 4.14 r (0,0648 mol) of pyromellitic dianhydride and carrying out the reaction at 15 to 20°C for 8 hours.

The rotational viscosity of this reaction product liquid at 25° C. was 477 inch voids.

After purifying this reaction product solution in the same manner as in Example 1,
Coated on a glass substrate with a spinner and placed in an oven for 300 min.
Heat it at ℃ for 1 hour.

hardened. Although the surface of the resulting coating film was smooth, it peeled off 100% in the adhesion test.

Use test 1 The coating film obtained by the method shown in Examples 1 and 2 was rubbed 30 times with lens clean paper, and the cell thickness was approximately 10
It was adjusted to have a diameter of μm and assembled into a TN cell with a 90 mm screw.

In this TN cell, P-type nematic (hereinafter referred to as r) manufactured by Chisso ■
It is abbreviated as N p fjl J. )Liquid crystal material LIXON
(registered trademark) GR-63 was injected and the pre-tilt angle θ was measured. The results are shown in Table 2.

The principle of measuring the pre-tilt angle is as shown below. (
(See Figure 1 (,) to (c)) When liquid crystal molecules are aligned at a pre-tilt angle of 0 degrees and an applied voltage V below the threshold voltage vth is applied to measure the aIIt rate, the liquid crystal molecules do not move. Therefore, the dielectric constant ε observed is 1. Corresponds to bBlilyu. (Figure 1 (a)) When an applied voltage exceeding the threshold voltage is applied, the liquid crystal molecules gradually rise, and at a sufficiently high applied voltage, C0
It becomes equal to the b8 beam. (FIG. 1(b)) At an intermediate applied voltage, C0b is expressed as the sum of vectors on C5 and 8 as shown in equation (1). At that time, 0 indicates the tilt of the liquid crystal molecules.

εobs='z sinθ+e, Lco8θ (1)
By the way, if the liquid crystal molecules are oriented obliquely with a pre-tilt angle θ from the beginning, apply a sufficiently low applied voltage (threshold voltage vth) to g. When we measure b, 'obs
It is obvious that it can be expressed by equation (1).

Therefore, in this pre-tilt angle measurement, we first measured ε and C of the nematic liquid crystal material injected into the cell, and then drew a graph showing the relationship between θ and C0bs'' using equation (1). The Sipre tilt angle θ was determined from the graph from the measured I.b.The dielectric constant 'obs+ was determined by applying 0.5V with a sine wave of I KHz and before injecting the liquid crystal material into the cell. It was determined from the subsequent capacity ratio.

The coating solution shown in Comparative Example 1 was applied onto a glass substrate treated with a silane coupling agent by the method shown in Comparative Example 1, and the resulting coating film was heated (hereinafter referred to as "the coating film of Comparative Example 1"). ) was rubbed 25 times with lens clean paper, adjusted to v4 so that the cell thickness was approximately 10 μm, and then
It was assembled into a TN cell with an IIt screw. The same nematic liquid crystal LIXON (registered trademark) GR-63 as this TN cell
was injected, and the pre-tilt angle 0 was measured using the method described above. The results are shown in Table 2.

Second! l! It can be seen that while the conventional polyimide film results in horizontal orientation, the film of the present invention provides oblique orientation.

Use test 2 The coating films of Examples 3 to 6 and Comparative example 1 were applied to Lens Clean.
The cell was rubbed 30 times with paper, adjusted to have a cell thickness of about 10 μm, and assembled into a TN cell with a 90 degree screw. Chisso Shishi's Np type liquid crystal material LIXON (registered trademark) 3046-15 was injected into this TN cell, and pre-injected using the method described above.
A tilt angle of 0 was measured. The results are shown in Table 3.

Table 3 It can be seen that conventional polyimide films tend to have a horizontal orientation, but all the coating films according to the present invention have an oblique orientation. Furthermore, as the ODSE ratio of the raw material composition increases, the pre-tilt angle θ also increases.

It can be seen that the pre-tilt angle can be freely controlled by changing the 0DSE ratio.

Usage Test 3 The coating films of Example 7 and Comparative Example 1 were rubbed with lens clean paper 30 times until the cell thickness was approximately 10 μmK. It was then assembled into a TN cell with a 90 degree twist. In this TN cell, Chisso ■ (DNpfflQ crystal material LIXO
N (Registered Trademark G) 3046-15 was injected, and the shake and tilt angles were measured using the method described above.

The results are shown in Section 4!2.

Table 4 It can be seen that conventional polyimide has a horizontal orientation, but the coating film according to the present invention has an oblique orientation.

Brief explanation of the previous issue Figure 1 (a) When the shake/tilt angle of a liquid crystal cell injected with IiNpm liquid crystal is 0 degrees, the induced voltage observed by applying a lower voltage than the L threshold Figure 2 (b) shows the fit rate εoba observed when a voltage sufficiently higher than the threshold voltage is applied to a liquid crystal cell injected with NpW liquid crystal. bs
(C) shows the t observed when the liquid crystal molecules are tilted at 0 degrees in a liquid crystal cell injected with Np type liquid crystal. It is a figure showing b.

that's all Patent issuer Chisso Co., Ltd. Agent: Patent Attorney Yatabe Sasai Same as above Katsu No Naka J

Claims (2)

[Claims] (1) A tetracarboxylic dianhydride represented by the following formula (1), a diamine represented by the formula (2), and an aminosilicon compound represented by the formula (3) are mixed in a solvent, a reaction is performed, and the necessary A coating liquid for a super twist birefringence effect type liquid crystal alignment film, which contains a soluble polyimidosiloxane precursor obtained by adding a silicon compound represented by formula (4) and optionally performing a heating reaction. ▲There are mathematical formulas, chemical formulas, tables, etc.▼……………(1) NH_2-R^2-NH_2………(2) NH_2-R^3-SiR^4_3_-_mX^4_m
………(3) Si(R^5)_3X^2………(4) [In formulas (1) to (4), R^1 represents a tetravalent carbocyclic aromatic group, R^2 is a linear or branched aliphatic group having 2 to 50 carbon atoms, an aromatic aliphatic group having 6 to 50 carbon atoms, or a polysiloxane group represented by the following formula (5),
R^3 is -(CH_2)＿■-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However,
Here, ■ represents an integer from 1 to 4. ), R^4 independently represents an alkyl group having 1 to 20 carbon atoms, a phenyl group, or an alkyl-substituted phenyl group having 1 to 20 carbon atoms,
X^1 and X^2 independently represent an alkoxy group, acetoxy group, halogen or hydroxyl group, and R^5 independently represents R^
4. Represents X^2 or the following formula (6), ▲There are mathematical formulas, chemical formulas, tables, etc.▼…………(6) (Here l takes a value of 1≦1≦100.)R＾5 are not all R^4 at the same time, and m takes a value of 1≦m≦3. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (5) Groups or alphabetic characters with the same symbol independently represent groups or numbers within a given range even if the general formulas containing them are different. Same below. ] (2) A tetracarboxylic dianhydride represented by the following formula (1), a diamine represented by the formula (2), and an aminosilicon compound represented by the formula (3) are mixed in a solvent, a reaction is performed, and the necessary A coating liquid for a liquid crystal alignment film containing a soluble polyimide siloxane precursor obtained by adding a silicon compound represented by formula (4) and optionally performing a heating reaction is applied onto a glass substrate.
A super twist birefringence effect type liquid crystal alignment film formed by heating to 300° C. to evaporate the solvent, crosslink the precursor, and harden the precursor. ▲There are mathematical formulas, chemical formulas, tables, etc.▼…………(1) NH_2-R^2-NH_2…………(2) NH_2-R^3-SiR^4_3_-_mX^1_m
………(3) Si(R^5)_3X^2…………(4) [In formulas (1) to (4), R^1 represents a tetravalent carbocyclic aromatic group, R^2 is a linear or branched aliphatic group having 2 to 50 carbon atoms, an aromatic aliphatic group having 6 to 50 carbon atoms, or a polysiloxane group represented by the following formula (5); 3 is -(CH_2)■-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However,
Here, _■ represents an integer from 1 to 4. ), R^4 independently represents an alkyl group having 1 to 20 carbon atoms, a phenyl group or an alkyl-substituted phenyl group, X^1 and X^2 independently represent an alkoxy group, an acetoxy group, a halogen or a hydroxyl group, R^5 independently represents R^4, X^2 or the following formula (6) ▲There are mathematical formulas, chemical formulas, tables, etc.▼…………(6) (Here l is a value of 1≦l≦100 ) All of R^5 do not become R^4 at the same time, and m takes a value of 1≦m≦3. ▲There are mathematical formulas, chemical formulas, tables, etc.▼……(5)]