WO2008010483A1 - Resin composition for retardation thin film, color filter substrate for liquid crystal display device, liquid crystal display device, and method for production of color filter substrate for liquid crystal display device having retardation thin film attached thereto - Google Patents

Abstract

Disclosed is a resin composition for a retardation thin film, which can form a retardation thin film having high transparency and high birefringency by applying the composition onto a substrate without the need of an alignment or stretching process. The composition comprises a polyimide precursor produced by reacting at least one tetracarboxylic acid dianhydride with at least one diamine and an organic solvent, wherein at least either one of the at least one tetracarboxylic acid dianhydride and the at least one diamine is an alicyclic compound. The composition can be used in a liquid crystal display device for forming a retardation thin film having an optically negative uniaxial anisotropy, an optical axis approximately perpendicular to a the surface of the thin film and a birefringence (Δn) in the thicknesswise direction of 0.01 to 0.3.

Description

 Specification

 RESIN COMPOSITION FOR RELATING THIN FILM, COLOR FILTER SUBSTRATE FOR LIQUID CRYSTAL DISPLAY DEVICE, AND LIQUID CRYSTAL DISPLAY DEVICE, AND METHOD FOR PRODUCING COLOR FILTER SUBSTRATE FOR LIQUID CRYSTAL DISPLAY DEVICE WITH RELATING THIN FILM

 Technical field

 The present invention relates to a resin composition for a retardation film, a color filter substrate for a liquid crystal display device, a liquid crystal display device, and a method for producing a color filter substrate for a liquid crystal display device with a retardation film.

 Background art

 Currently, liquid crystal display devices are used in various applications such as notebook PCs, portable information terminals, desktop monitors, and digital cameras, taking advantage of characteristics such as light weight, thinness, and low power consumption. Liquid crystal display devices are required to have a wider viewing angle with the expansion of screens and monitor applications.

 The reason why the viewing angle of a liquid crystal display device is narrower than that of a self-luminous cathode ray tube (CRT) display device or a plasma display device is that a liquid crystal display device generally has a structure in which a liquid crystal layer is sandwiched between two polarizing films. Therefore, the difference in the retardation of the liquid crystal layer resulting from the difference in the traveling direction of light affects the transmission intensity. That is, in the oblique direction, the retardation increases, so that the incident linearly polarized light becomes elliptically polarized light, and the amount of light leakage in the dark state increases, leading to a decrease in contrast.

 [0004] Therefore, in order to suppress a decrease in contrast in an oblique direction, it is effective to use a retardation film for compensating for retardation of the liquid crystal layer. Currently, in a twisted 'nematic liquid crystal display device, the viewing angle is widened by attaching a viewing angle widening film made of discotic liquid crystal as a retardation film.

 [0005] On the other hand, VA (Vertical Alignment) method, IPS (In-plane Switching) method, etc., which are new liquid crystal display methods aiming at widening the viewing angle, have been developed.

[0006] A biaxially stretched retardation film is also used for the VA method in order to further increase the viewing angle. However, the production of these films is not easy, and the orientation or Since the stretching process is indispensable, the process is troublesome.

 [0007] To solve this problem, a polyimide retardation film having an optically negative uniaxial anisotropy and having an optical axis perpendicular or substantially perpendicular to the thin film surface is provided. A method for enlarging the field angle has been proposed. (Patent Document 1)

 [0008] Polyimide exhibits the function of a retardation film because it has an aromatic ring or aromatic heterocycle in the main chain direction of the polymer, and therefore has a refractive index in the main chain direction as compared to the direction perpendicular to the main chain. And the birefringence as a molecule increases, and the molecular chain easily aligns parallel to the substrate, so the difference in refractive index between the film thickness direction and the direction parallel to the film surface (birefringence as a film). Due to refraction).

 [0009] However, the above-mentioned polyimide retardation thin film has a strong light absorption due to the aromatic molecular structure and cannot be said to have sufficient transparency. The white display on the device was yellowish, and there was a problem in image display quality.

 [0010] In order to improve the transparency of the polyimide, an acid component having a non-aromatic group such as an alicyclic group is introduced into the polyimide resin to prevent intramolecular conjugation and charge transfer complex formation. It has been proposed (Patent Documents 2 to 4). In addition, it has been proposed to apply a polyimide resin having high transparency and low birefringence with improved transparency and reduced orientation birefringence and stress birefringence as an optical element. (Patent Documents 5 to 7).

On the other hand, as a polyimide material suitable for a retardation film, a polyimide material having high transparency and high birefringence has been demanded.

Patent Document 1: Japanese Patent Laid-Open No. 2001-290023

 Patent Document 2: Japanese Patent Laid-Open No. 7-56030

 Patent Document 3: Japanese Patent Laid-Open No. 9-73172

 Patent Document 4: Japanese Patent Laid-Open No. 2002-161136

 Patent Document 5: Japanese Patent Laid-Open No. 10-221549

 Patent Document 6: Japanese Patent Laid-Open No. 11-60732

 Patent Document 7: Japanese Patent Laid-Open No. 2005-163012

 Disclosure of the invention

Problems to be solved by the invention [0013] The present invention does not require an orientation and stretching step, and can form a highly transparent and highly birefringent retardation film by coating on a substrate, the retardation film resin composition, and the retardation oen

 The present invention provides a color filter substrate having a thin film, a wide viewing angle, high contrast liquid crystal display device, and a method for producing a color filter substrate for a liquid crystal display device with a retardation film.

 Means for solving the problem

In order to solve the above problems, the present invention has the following configuration.

 1. Used in liquid crystal display devices, has optically negative uniaxial anisotropy, the optical axis is substantially perpendicular to the thin film surface, and the birefringence Δη in the thickness direction is 0.01 to 0.3. A resin composition for forming a retardation film, comprising: a polyimide precursor obtained by reacting at least one tetracarboxylic dianhydride and at least one diamine; and an organic solvent. A resin composition for forming a retardation film, wherein at least one of the at least one tetracarboxylic dianhydride and the at least one diamine is an alicyclic compound.

 2. Diamine, an alicyclic compound, has the following general formula (1)

[0015] [Chemical 1]

(In the formula, R ¹ represents a monovalent organic group or a hydrogen atom.)

 2. The composition according to 1, which is a trans-1,4-diaminocyclohexane compound represented by the formula: 3. Tetracarboxylic dianhydride has the following general formula (2)

 [0016] [Chemical 2]

(In the formula, R ² and R ³ each independently represent a monovalent organic group or a hydrogen atom.) 3. The composition according to 2, which is a 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride compound represented by the formula:

 [0017] 4. The composition according to item 3, wherein the polyimide precursor has at least a structural unit represented by the following general formula (3).

[0018] [Chemical 3]

(Where R ² ,

R ⁴ and R ⁵ each independently represent a monovalent organic group or a hydrogen atom. )

 [0019] 5. The composition according to 1, wherein the compound is a tetracarboxylic dianhydride strength 1,2,3,4-cyclobutane tetraforce rubonic acid dianhydride which is an alicyclic compound.

 6. The composition according to 5, wherein the diamine is an aromatic diamine having a rigid molecular structure.

[0020] 7. The composition according to item 6, wherein the aromatic diamine having a rigid molecular structure is at least one selected from P-phenolenediamine, 4,4 and diaminobenza-lid force.

 8. The following general formula (1)

[0021] [Chemical 4]

(In the formula, R ¹ represents a monovalent organic group or a hydrogen atom.)

 A diamine component including a trans-1,4-diaminocyclohexane compound represented by the following general formula (2):

[0022] [Chemical 5]

(In the formula, R ² and R ³ each independently represent a monovalent organic group or a hydrogen atom.)

 A liquid crystal containing a polyamic acid compound obtained by reacting a tetracarboxylic dianhydride component including a 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride compound represented by A resin composition for use in a display device to form a retardation thin film having optically negative uniaxial anisotropy and an optical axis being substantially perpendicular to a thin film surface.

 [0023] 9. The composition according to item 8, which has at least a structural unit represented by the following general formula (3):

 [0024] [Chemical 6]

(Where

R ⁴ and R ⁵ each independently represent a monovalent organic group or a hydrogen atom. )

[0025] 10. R ¹ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, R ² ,

10. The composition according to 9, wherein R ⁴ and R ⁵ are hydrogen atoms.

[0026] 11. The composition according to item 9 or 10, further comprising at least one structural unit selected from the group consisting of structural unit forces represented by the following general formulas (4) to (8): object.

[0027] [Chemical 7]

[0028] [Yi 8]

(In the formulas (4), (5), (6), (7) and (8),

R ⁴ and R ⁵ each independently represent a monovalent organic group or a hydrogen atom. )

[0031] 12. In the formulas (4), (5), (6), (7) and (8), R ¹ is a hydrogen atom or a linear or branched chain having 1 to 4 carbon atoms. An alkyl group, R ² ,

11. The composition according to 10, wherein R ⁴ and R ⁵ are hydrogen atoms.

 [0032] 13. The total content of structural units represented by the formula (3), (4), (5), (6), (7) or (8) is the total structural unit constituting the polyamic acid. 13. The composition according to 11 or 12, which is 50 mol% or more.

[0033] 14. Part or all of the amine end groups of the polyimide precursor or the polyamic acid are

14. The resin composition according to any one of items 1 to 13, which is end-capped by an amic acid forming reaction with a dicarboxylic acid anhydride.

[0034] 15. The composition according to item 14, wherein the dicarboxylic anhydride is at least one dicarboxylic anhydride in which maleic anhydride, phthalic anhydride, succinic anhydride, and nadic anhydride are also selected.

[0035] 16. Use of the composition according to any one of items 1 to 15 for the manufacture of a resin composition for forming a retardation film. [0036] 17. A color filter substrate for a liquid crystal display device in which pixels of each color of red, blue, and green are two-dimensionally arranged on a transparent substrate, and the liquid crystal display device according to any one of items 1 to 15 A color filter substrate for a liquid crystal display device, on which a retardation film formed from a resin composition for retardation film is formed.

 18. The retardation film has the following general formula (8)

[0037] [Chemical 11]

(Where

R ² and R ³ each independently represent a monovalent organic group or a hydrogen atom. )

 18. A color filter substrate according to claim 17, comprising polyimide containing at least 50 mol% of the structural unit represented by

[0038] 19. The color filter substrate according to 18, wherein R ¹ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and R ² and R ³ are hydrogen atoms.

 20. The liquid crystal display device according to any one of items 17 to 19, wherein the phase difference thin film formed by the resin composition for the phase difference thin film is formed so as to cover the pixel. Color filter board.

 [0040] 21. A liquid crystal display device using the color filter substrate for a liquid crystal display device according to any one of items 17 to 20, wherein the display method of the liquid crystal display device is when no voltage is applied. The liquid crystal display device is a liquid crystal display device in which the liquid crystal molecules are aligned in a direction substantially perpendicular to the liquid crystal cell surface, and the liquid crystal molecules are aligned in a direction substantially parallel to the liquid crystal cell surface when a voltage is applied.

 [0041] 22. The resin composition for retardation film according to any one of items 1 to 15, wherein the red, blue and green pixels are two-dimensionally arranged on a transparent substrate. A method for producing a color filter substrate for a liquid crystal display device with a retardation film, which comprises applying a heat treatment to a surface of the filter substrate on which the pixels are arranged and heat-treating the surface.

The invention's effect [0042] The phase difference thin film for a liquid crystal display device can be easily formed by using the resin composition for the phase difference thin film of this configuration, and further, the viewing angle characteristics and contrast of the liquid crystal display device can be further improved by the phase difference thin film. I can plan.

 BEST MODE FOR CARRYING OUT THE INVENTION

 [0043] Hereinafter, the present invention will be described in more detail.

 The resin composition for retardation film of the present invention is used in a liquid crystal display device, has optically negative uniaxial anisotropy, an optical axis is substantially perpendicular to the thin film surface, and the thickness direction A resin composition for a retardation film for forming a retardation film having a birefringence Δη of 0.01 to 0.3, and a polyimide precursor obtained by reacting tetracarboxylic dianhydride with diamine. And at least one of tetracarboxylic dianhydride and diamine is an alicyclic compound.

 [0044] The polyimide precursor used in the present invention is a polyamic acid, polyamic acid ester, polyamic acid partial ester, polyamic acid silyl ester, polyamic acid salt, polyisoimide, or the like, which can be heated or chemically converted to polyimide. It's okay to make a difference.

 As diamine which is an alicyclic compound used for obtaining a polyimide precursor, trans-1,4-diaminocyclohexane compound represented by the following general formula (1) is preferable. .

[0046] [Chemical 12]

(In the formula, R ¹ represents a monovalent organic group or a hydrogen atom.)

Here, R ¹ is preferably an organic group having 1 to 30 carbon atoms or a hydrogen atom, and more preferably a methyl group, an ethyl group, a η-propyl group, an isopropyl group, a η-butyl group, an isobutyl group. And a straight-chain or branched alkyl group having 1 to 4 carbon atoms such as sec-butyl group or a hydrogen atom. Of these, trans-1,4-diaminocyclohexane, trans-1,4-diamino-2-methylcyclohexane, and trans-1,4-diamino-2,5-dimethylcyclohexane are particularly preferred. Trans-1,4-diaminocyclohexane is preferred.

[0048] In 1,4-diaminocyclohexane compounds, the configuration of the amino group at positions 1 and 4 is trans There are trans isomers that are cis configurations and cis isomers that are cis configurations. Usually, trans-1,4-diaminocyclohexane compound is obtained by hydrogenating the precursor P-phenylenediamine compound, but the product of this reaction is trans form and cis form. (For example, Japanese Patent Publication No. 51-48198). As a suitable trans-1,4-diaminocyclohexane compound used in the present invention, a product obtained by separating and purifying the hydrogenated compound according to a known method such as distillation, recrystallization or the like is used. The cis-isomer content is not particularly limited as long as the effects of the present invention are not impaired. It is usually recommended to refine the cis-isomer content to 50% by weight or less, preferably 30% by weight or less, more preferably 10% by weight or less. By setting the cis-isomer content in the above range, it is possible to suppress a decrease in the orientation of the polyimide molecular chain due to the bent structure of the cis-isomer, and to obtain birefringence sufficient for practical use.

[0049] Reducing the coloring component by repeating purification by recrystallization of a trans-1,4-diaminocyclohexane compound using a solvent such as n-hexane increases transparency. This is an effective method.

 [0050] The trans-1,4-diaminocyclohexane compound can be used in combination with another diamine compound as long as the effects of the present invention are not impaired. In this case, the proportion of the trans-1,4-diaminocyclohexane compound used is preferably 50 mol% or more, more preferably 70 mol% or more in the entire diamine, and 90 mol% or more. More preferably it is. If the proportion of trans 1,4-diaminocyclohexane compound used is lower than 50 mol%, the target characteristics of the present invention may not be obtained.

[0051] Examples of diamines that can be used in combination with trans-1,4-diaminocyclohexane compound include 2,2'-bis (trifluoromethyl) benzidine, p-phenylenediamine, and m-phenylenediamine. 2,4-diaminotoluene, 2,5-diaminotoluene, 2,4-diaminoxylene, 2,4-diaminodurene, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4 '-Diaminodiphenyl ether, 3,4'-Diaminodiphenyl ether, 4,4'-Diaminodiphenyl sulfone, 3,3'-Diaminodiphenyl sulfone, 4,4'-Diaminobenzophenone, 3,3'-Diamino Benzo phenone, 4,4'-diaminobenzaldehyde, benzidine, 3,3'-dihydroxybenzidine, 3,3'-dimethoxybenzidine, 0-tolidine, m-tolidine, 1,4-bis (4-aminophenoxy) Benzene, 1,3-bis (4-amino Phenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 4,4 Sibi (4-aminophenoxy) biphenyl, bis (4- (3-aminophenoxy) phenol) sulfone, bis (4- (4-aminophenoxy) phenol) sulfone, 2,2-bis (4- (4 -Aminophenol) phenol) bread, 2,2-bis (4- (4-aminophenoxy) phenol) hexafluoropropane, 2,2-bis (4-aminophenol) hexaflu Aromatic diamines such as chloropropane; 1,3-propanediamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, isophorone diamine, tetrahydrodicyclopenta-dirangeamine, hexahydro-4 7 Metanoinda two range methylenedioxy § Min, tricyclo [6.2.1.0 ^{2 '7]} - © down decimeter range methyldichlorosilane § Min, 4,4' main Chirenbisu (Kishiruamin cyclohexylene), 2,5 Noruborunanbisu (Mechiruamin ), 2,6-norbornambis (medium Ruamin), 2,7 Noruborunanbisu (Mechiruamin) include aliphatic and cycloaliphatic Jiamin such.

 [0052] When siloxane diamine is used as a part of diamine, adhesion to an inorganic substrate or the like can be improved. Siloxane diamine is usually preferably used in an amount of 1 to 20 mol% in the total diamine. A specific example of siloxane diamine is bis (3-aminopropyl) tetramethyldisiloxane.

[0053] The tetracarboxylic dianhydride to be reacted with diamine, which is an alicyclic compound, includes 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic dianhydride, pyromellitic anhydride, 3,4, 9, 10-perylene Tetracarboxylic dianhydride, 3,3 ', 4,4'-diphenylsulfone tetracarboxylic dianhydride, 4,4 oxydiphthalic dianhydride, 1,2,5,6-naphthalenetetracarboxylic Acid dianhydride, 3,3 ', 4,4'-paraterphenyl tetracarboxylic dianhydride, 3,3', 4,4 Aromatic tetracarboxylic dianhydrides such as (2,2-hexafluoroisopropylidene) diphthalic dianhydride; 1,2,3,4-butanetetracarboxylic dianhydride, 1,3 -Dimethyl-1,2,3,4-cyclobutanetetra Rubonic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,2,4,5-cyclohexanetetra Carboxylic dianhydride, 3,3 ', 4,4'-dicyclohexanetetracarboxylic dianhydride, 1,2,4,5-norbornene tetracarboxylic dianhydride, 5- (2,5-di Oxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, l, 3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5- (Dioxo-3-full) -N [1,2-c] furan-1,3-dione, l, 3,3a, 4,5,9b-hexahydro-5-methyl-5- (tetrahydro-2,5 dioxo-3-furan ) -Naphtho [1,2-c] furan-1,3-dione, l, 3,3a, 4,5,9b-hexahydr oen

 Mouth-5,8-dimethyl-5- (tetrahydro-2,5-dioxo-3-fural) -naphtho [1,2-c] furan-1,3-dione, bicyclo [2.2.2] -oct Aliphatic and alicyclic such as -7-en-2,3: 5,6-tetracarboxylic dianhydride, bicyclo [2.2.2] octane-2,3: 5,6-tetracarboxylic dianhydride And the formula tetracarboxylic dianhydride.

 Of these tetracarboxylic dianhydrides, substituted or unsubstituted 3,3 ′, 4,4 biphenyltetracarboxylic dianhydrides represented by the following general formula (2) may be used. It is more preferable to use 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride.

 [0055] [Chemical 13]

(In the formula, R ² and IT each represent a monovalent organic group or a hydrogen atom, and may be the same or different.)

In the formula (2), preferred examples of R ² and R ³ include hydrogen, an alkyl group having 1 to 3 carbon atoms, a halogenated alkyl group having 1 to 3 carbon atoms, a phenyl group, or a substituted phenyl group. In particular, hydrogen is preferable.

[0056] Along with the 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride compound, other tetracarboxylic dianhydrides may be used. In this case, the proportion of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride compound used is preferably at least 50 mol% in the total tetracarboxylic dianhydride 70 mol% More preferably, it is more preferably 90 mol% or more. This is because if the proportion of the 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride compound is less than 50 mol%, the target characteristics of the present invention may not be obtained.

[0057] A trans-1,4-diaminocyclohexane compound represented by the following general formula (1) and a substituted or unsubstituted 3,3 ', 4,4 represented by the following general formula (2): Biphenyl tetracarboxylic dianhydride The polyimide precursor obtained by reacting a physical compound preferably has a structural unit represented by the following general formula (3). In addition to the structural unit represented by the general formula (3), the structural unit represented by the general formulas (4) to (8) may be included. These structural units are converted into the same structural unit represented by the general formula (8) by heating or chemical imidization reaction.

 [0058] [Chemical 14]

(Where

R ² , R ³ , R ⁴ and R ⁵ each represent a monovalent organic group or a hydrogen atom, and may be the same or different. )

 [0059] [Chemical 15]

 [0060] [Chemical 16]

 [0061] [Chemical 17]

[0062] [Chemical 18]

 [0063] [Chemical 19]

(In Formula (3)-Formula (8),

R ² , R ³ , R ⁴ and R ⁵ each represent a monovalent organic group or a hydrogen atom, and may be the same or different. )

In the formula (3) to (8), preferred examples of R ¹ and R ² and R ³ are as described in the description of each of the above formulas (1) and formula (2), R ⁴ and R Preferred examples of ⁵ include a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, a phenol group, or a substituted phenol group. .

 [0064] The ratio of the structural units represented by the general formulas (3) to (8) in the polyimide precursor to the total structural units is preferably 50 mol% or more, more preferably 70 mol% or more. . If the proportion of the structural units represented by the general formulas (3) to (8) is lower than 50 mol%, the target characteristics of the present invention may not be obtained. As described above, after imidization by heating or the like, these structural units become structural units represented by the general formula (8). Therefore, in the polyimide after imidization, the structure represented by the general formula (8) is used. The proportion of units to the total structural units is preferably 50 mol% or more, more preferably 70 mol% or more.

[0065] The present invention also provides a diamine component containing a trans-1,4-diaminocyclohexane compound represented by the general formula (1), and a 3,4-diaminocyclohexane compound represented by the general formula (2). Used in a liquid crystal display device comprising a polyamic acid compound obtained by reacting a tetracarboxylic dianhydride component including a 3 ′, 4,4′-biphenyltetracarboxylic dianhydride compound and an organic solvent, There is also provided a resin composition for forming a retardation film having optically negative uniaxial anisotropy and an optical axis being substantially perpendicular to the thin film surface. In this case, preferably, the polyamic acid compound has at least a structural unit represented by the general formula (3). Formed The birefringence Δη in the thickness direction of the phase difference thin film is preferably 0.01 to 0.3. The trans-1,4-diaminocyclohexane compound represented by the general formula (1) and the 3,3 ′, 4,4′-biphenyltetracarboxylic acid represented by the general formula (2) The above explanation can be applied as it is to the explanation regarding the acid dianhydride compound and the preferred compounds included therein.

 [0066] The polyimide precursor can be obtained by a known method by reacting tetracarboxylic dianhydride with diamine. The polyamic acid ester is a tetracarboxylic acid diester obtained by esterifying a tetracarboxylic dianhydride with an organic substance having an alcoholic hydroxyl group, as described in, for example, JP-A-8-92496. Later, acid chloride, and then react with diamine. Tetracarboxylic dianhydride is esterified with an organic substance having an alcoholic hydroxyl group to form a tetracarboxylic diester, reacted with carpositimides, and then reacted with diamine. Obtained by. The polyamic acid partial ester is, for example, a method in which an organic substance having a glycidyl group or an isocyanate group is added to a carboxyl group of a polyamic acid obtained by reacting tetracarboxylic dianhydride and diamine. As described in 2000-212216, it can be obtained by a method of reacting an acetal compound with a carboxyl group of a polyamic acid obtained by reacting tetracarboxylic dianhydride and diamine. The polyamic acid silyl ester is described in, for example, JP-A-64-63070, JP-A-2001-72768, JP-A-2005-146073, and the diamine is converted into bissilylidamine by a silylating agent. Thereafter, it is obtained by a method of reacting with tetracarboxylic dianhydride.

 [0067] It is preferable to use 1,2,3,4-cyclobutanetetracarboxylic dianhydride as the tetracarboxylic dianhydride which is an alicyclic compound used for obtaining a polyimide precursor. 1,2,3,4-Cyclobutanetetracarboxylic dianhydride can be obtained by a known method (for example, Japanese Patent Publication No. 2-619 56, Japanese Patent Laid-Open No. 3-137125, J. Polym. Sci .: Part A: Polymer Chemistry, 38 卷, 108 (2000)).

[0068] It is also possible to use both 1,2,3,4-cyclobutanetetracarboxylic dianhydride and other tetracarboxylic dianhydrides. In this case, the proportion of 1,2,3,4-cyclobutanetetracarboxylic dianhydride used is preferably 50 mol% or more in the total tetracarboxylic dianhydride, and more preferably 70 mol% or more. It is more preferable that it is 90 mol% or more preferable. If the proportion of 1,2,3,4-cyclobutanetetracarboxylic dianhydride used is as low as 50 mol%, the intended characteristics of the present invention may not be obtained.

 [0069] The tetracarboxylic dianhydride used together with 1,2,3,4-cyclobutanetetracarboxylic dianhydride includes 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2 , 3,3 ', 4'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic dianhydride, pyromellitic anhydride, 3,4,9, 10-perylenetetracarboxylic dianhydride, 3,3 ', 4,4'-diphenylsulfonetetracarboxylic dianhydride, 4,4'-oxydiphthalic dianhydride, 1,2,5,6- Naphthalenetetracarboxylic dianhydride, 3,3 ', 4,4'-paraterphenyl tetracarboxylic acid dianhydride, 3,3', 4,4'-metatertetracarboxylic dianhydride 4,4 (aromatic isopropylidene), aromatic dicarboxylic dianhydrides such as diphthalic dianhydride; 1, 2, 3, 4 butanetetracarboxylic dianhydride, 1,3 -Dimethyl-1,2,3,4-si Lobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-triforce ruboxycyclopentylacetic acid dianhydride, 1,2,4,5-cyclo Xanthatetracarboxylic dianhydride, 3,3 ', 4,4'-dicyclohexanetetracarboxylic dianhydride, 1,2,4,5-norbornene tetracarboxylic dianhydride, 5- (2, 5-Dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, l, 3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2 , 5-Dioxo-3-furyl) -naphtho [1,2-c] furan-1,3-dione, l, 3,3a, 4,5,9b-hexahydro-5-methyl-5- ( Tetrahydro-2,5-dioxo-3-furyl) -naphtho [1,2-c] furan-1,3-dione, l, 3,3a, 4,5,9b-hexahydro-5,8- Dimethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, bicyclo [2.2.2]- Oct-7-ene-2,3: 5, 6-tetra-force carboxylic dianhydride, bicyclo [2.2.2] octane-2,3: 5,6-tetracarboxylic dianhydride And alicyclic tetracarboxylic dianhydrides.

[0070] As the diamine reacted with the tetracarboxylic dianhydride which is an alicyclic compound, it is preferable to use an aromatic diamine having a rigid molecular structure for the purpose of obtaining a highly birefringent retardation film. . Here, an aromatic diamine having a rigid molecular structure is a structure in which the change in the relative position of the two amino groups constituting the diamine is small, the conformation change due to the thermal motion of the molecule is small. Say aromatic diamine with. Preferably, (1) a benzene ring, an aromatic heterocyclic ring, or a condensed ring force of them is selected. A structure in which two amino groups are facing each other, and the CN bond of one amino group and the C—N bond of the other amino group are approximately collinear or approximately parallel. (2) benzene ring, aromatic heterocyclic ring, or their condensed ring force Group force selected Two or more structural unit forces, which are linked directly or via an amide bond Two amino groups are facing each other, and the CN bond of one amino group and the C—N bond of the other amino group are approximately on the same straight line, or have a structure that is approximately parallel. Says the aromatic diamine.

 [0071] Examples of the aromatic diamine having a rigid molecular structure include compounds represented by the following formulas (9) to (11).

 [0072] [Chemical 20]

(Where R ⁶ , R ⁷ , R °, R ⁹ and R ^1Q are -H, -CH, -OH, -CF, -SO H, -COOH, respectively.

 3 3 3

, -CONH, -F, -Cl, -Br, -CF and -OCH

 2 3 3

 Each group may be the same or different. )

[0075] Specific examples of the aromatic diamine having a rigid molecular structure include 4,4'-diaminobenzanilide, benzidine, 3, 3, -dimethylbenzidine, 3,3, -dihydroxybenzidine, 3, 3'— Dimethoxybenzidine, 2,2'-dimethylbenzidine, 2,2'-bis (trifluoromethyl) benzidine, p-ferylenediamine, 2,5 diaminotoluene, 3,6 diaminodurene, m-phenylenediamine, 2,4 diaminotoluene, 2, 4 Diaminoxylene I can get lost. Among these, 4,4,1-diaminobenzaldehyde, p-phenylenediamine, 2,2,1-dimethylbenzidine and 2,2'-bis (trifluoromethyl) benzidine can be preferably used. -Lido and p-phenoldiamine are more preferred. A retardation film containing a polyimide obtained by reacting these diamines with 1,2,3,4 cyclobutanetetracarboxylic dianhydride is preferably used because it has particularly high transparency and high birefringence. . The above diamine can be used alone or in combination of two or more.

 [0076] In addition, an aromatic diamine having a rigid molecular structure may be used in combination with another diamine. In this case, the proportion of aromatic diamine having a rigid molecular structure is preferably 50 mol% or more, more preferably 70 mol% or more, more preferably 90 mol% or more of the total diamine. More preferably. If the use ratio of the aromatic diamine having a rigid molecular structure is lower than 50 mol%, the intended characteristics of the present invention may not be obtained.

 [0077] Other diamines that can be used together with an aromatic diamine having a rigid molecular structure include 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, and 4,4'-diaminodiphenyl ether. 3, 4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3, 3'-diaminodiphenyl sulfone, 4, 4'-diaminobenzophenone, 3, 3, -diaminobenzophenone, 1,4bis ( 4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, bis (4- (3-aminophenoxy) Phenol) sulfone, bis (4— (4 aminophenoxy) phenol) sulfone, 2,2 bis (4— (4 aminophenoxy) phenol) propane, 2,2 bis (4— ( Aromatic diamines such as 4-aminophenoxy) phenol) hexafluoropropane and 2,2-bis (4-aminophenol) hexafluoropropane can be used.

[0078] In addition, 1,3 propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, trans 1,4-diaminocyclohexane, cis 1,4-diaminocyclohexane, isophorone diamine Mine, Tetrahydrodicyclopentadenylenediamine, Hexahydro-1,7-Methanoindanylenediethylenediamine, Tricyclo [6. 2. 1. 0 ² ' ⁷ ] —U Aliphatics such as ndecylenedimethyldiamine, 4,4'-methylenebis (cyclohexylamine), 2,5 norbornanebis (methylamine), 2,6 norbornanebis (methylamine), 2,7 norbornanebis (methylamine) and Alicyclic diamines can also be used.

 [0079] When siloxane diamine is used as a part of diamine, adhesion with an inorganic substrate or the like can be improved. Siloxane diamine is usually preferably used in an amount of 1 to 20 mol% in the total diamine. Specific examples of siloxane diamine include bis (3-aminopropyl) tetramethyldisiloxane.

 [0080] The reaction of tetracarboxylic dianhydride and diamine can be carried out by mixing in a polar organic solvent. At this time, the degree of polymerization of the resulting polyamic acid can be adjusted by the mixing ratio of tetracarboxylic dianhydride and diamine. The proportion of tetracarboxylic dianhydride and diamine used in the polyamic acid synthesis reaction is 0.2 mol of tetracarboxylic dianhydride acid anhydride group with respect to 1 equivalent of amino group contained in diamine. A ratio of ˜2 equivalents is preferable, and a ratio of 0.8 to 1.2 equivalents is more preferable. Similar to the usual polycondensation reaction, the closer the molar ratio of tetracarboxylic dianhydride to diamine is to 1, the higher the degree of polymerization of the polymer produced. If the degree of polymerization is too small, the strength of the polyimide coating film becomes insufficient, and if the degree of polymerization is too large, workability at the time of forming the polyimide coating film may be deteriorated. Therefore, the degree of polymerization of polyamic acid has a reduced viscosity (also referred to as r? SpZC) of 0.05 to 5. Odl / g (measured at a concentration of 0.5 g / dl in N-methylpyrrolidone at a temperature of 30 ° C). Preferred 0.1-2. OdlZg is more preferred.

[0081] Further, in order to seal part or all of the amino group or carboxyl group of the polyamic acid molecule for the purpose of improving heat resistance and workability, dicarboxylic acid anhydride, monoamine compound, monoisocyanate are used. It is also possible to add a compound or the like to the reaction system. Examples of dicarboxylic acid anhydrides include maleic anhydride, phthalic anhydride, 4-methyl phthalic anhydride, 4-tert butyl phthalic anhydride, itaconic anhydride, and nadic anhydride. Examples of monoamine compounds include a-line, cyclohexylamine, n-butylamine, n-pentylamine, and n-hexylamine. Examples of monoisocyanate compounds include phenol isocyanate and naphthyl isocyanate. In particular, some or all of the amine end groups Preferably end-capped by amic acid formation reaction with rubonic anhydride. Maleic anhydride, phthalic anhydride, succinic anhydride, and dianhydric acid power are selected from dicarboxylic anhydrides. The dicarboxylic acid anhydride is preferably used.

[0082] The polyamic acid synthesis reaction is preferably carried out in an organic solvent under a temperature condition of -20 to 200 ° C, more preferably 0 to 150 ° C. Here, the organic solvent is not particularly limited as long as it can dissolve the synthesized polyamic acid. For example, N-methyl-2-pyrrolidone, N, N dimethylacetamide, N, N dimethylformamide, dimethyl sulfoxide, γ Examples include aprotic polar solvents such as petit-mouth rataton, tetramethinoreurea, 1,3 dimethyl-2-imidazolidinone, and hexamethylphosphoramide. The amount of the organic solvent used is preferably such that the concentration of the solid content including tetracarboxylic dianhydride and diamine is 0.1 to 30% by weight based on the total amount of the reaction solution. Yes.

[0083] For the organic solvent, alcohol, ketone, ester, ether, halogenated hydrocarbon and hydrocarbon, which are poor solvents for polyamic acid, can be used in combination as long as the polyamic acid to be produced does not precipitate. . Specific examples of strong anti-solvents include, for example, methylanolenoleole, ethenoreanoreconolele, isopropinoleanoreconole, cyclohexanolenole, ethylene glycol, propylene glycol, 1,4 butanediol, diethyleneglycolene, triethylene Ethylene glycol, 3-methyl-3-methoxybutanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl 3-methoxypropionate, 3- Methyl-3-methoxybutyl acetate, ethyl ethoxypropionate, cetyl oxalate, methyl malonate, jetyl ether, tetrahydrofuran, ethylene glycol methyl ether, ethylene glycol eno eno oleate Les, ethylene glycol Honoré _eta - Puropinoreete le, ethylene glycol isopropyl ether, ethylene glycol _eta - Buchirue Tenore ethyleneglycidyl Kono regime Chino les ether Honoré ethyleneglycidyl Kono Ree Chino les ether Bruno rare Seteto, diethylene glycol Honoré mono- methylol Honoré ether, diethylene Glycole Monomethinore Ethenore, Diethylene Glycono Resin Metinore Ethenore, Diethylene Glyco Gnore Gécinore Iter, Diethylene Glycol Monomethyl Ether Acetate, Diethylene Glyco Gnore Monoetinoreethenoreacetate, Propylene glycolenoremonoetinoreate acetate

, Dichloromethane, 1,2 dichloroentane, 1,4-dichlorobutane, trichloro ethane, black benzene, o dichroic benzene, hexane, heptane, octane, benzene, tolylene, and xylene.

 [0084] The resin composition for retardation film can be produced by adding an organic solvent to a polyimide precursor or a solution thereof and mixing them uniformly by a conventional method. The temperature at which the rosin composition is prepared is preferably 0 ° C to 200 ° C, more preferably 20 ° C to 60 ° C. Examples of the organic solvent include those exemplified as those used in the polyamic acid synthesis reaction. In addition, the poor solvents exemplified as those that can be used together in the synthesis reaction of the polyamic acid can be appropriately selected and used together.

 [0085] The solid content concentration in the rosin composition is selected in consideration of viscosity, volatility, etc., but is preferably in the range of 1 to 10% by weight. That is, the resin composition is applied to the substrate surface to form a coating film that becomes a retardation film, but when the solid content concentration is less than 1% by weight, the coating film thickness is too small. Thus, a good retardation film cannot be obtained, and if the solid concentration exceeds 10% by weight, the film thickness of the coating becomes excessive and a good retardation film cannot be obtained. In addition, the viscosity of the rosin composition is increased and the coating properties are inferior.

[0086] From the viewpoint of improving the adhesion to the substrate surface, the resin composition includes 3-aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, and N-phenyl-3-amide. Minopropyltrimethoxysilane, 3-Mercaptopropyltrimethoxysilane, 3 Glycidoxypropinoletrimethoxysilane, 2- (3,4 Epoxycyclohexenole) tiltrimethoxysilane, 3-Isocyanatopropyltrimethoxysilane , Compounds containing functional silanes such as 3-aminopropyltriethoxysilane and Z or bisphenol type epoxy resin, bisphenol A novolac type epoxy resin, biphenyl type epoxy resin, phenol novolak type epoxy resin , Alkylphenol novolac type epoxy resin, Polydaricol type Poxy resin, cycloaliphatic epoxy resin, cresol novolac type epoxy resin S, glycidinoreamine type epoxy resin S, naphthalene type epoxy resin, urethane-modified epoxy resin, rubber-modified epoxy Epoxy such as resin, epoxy-modified polysiloxane Epoxy group-containing compounds such as sebum may be contained. In addition, from the viewpoint of improving the film thickness uniformity and surface smoothness of the coating film, non-ionic surfactants such as polyoxyethylene lauryl ether and polyoxyethylene dilaurate, fluorine-based surfactants, and silane-based surfactants. A surfactant such as a surfactant and an acrylic acid copolymer-based surfactant may be contained. The content of these additives is such that the effects of the present invention are not adversely affected, and is usually 20% by weight or less, preferably 10% by weight or less, based on the total composition.

[0087] The resin composition is applied on a substrate by a dipping method, a roll coater method, a spinner method, a die coating method, a method using a wire bar, etc., and then air-dried, vacuum-dried, or oven hot plate is used. A coating film is formed by heating and drying. The heating conditions vary depending on the resin, solvent, and coating amount used. It is preferable to heat at 50 to 400 ° C for 1 to 300 minutes.

 The substrate to be coated may be a liquid crystal display substrate, that is, a color filter substrate or a TFT substrate itself. Alternatively, the resin composition may be applied to the base film and then pasted on the liquid crystal display substrate through an adhesive layer. These are formed on the substrate surface opposite to the liquid crystal layer. Alternatively, it may be formed on the surface of the substrate for a liquid crystal display device that is in contact with the liquid crystal layer. For example, the above-mentioned resin composition may be applied to the surface on the side where pixels are formed on a color filter substrate for a liquid crystal display device in which pixels of each color of red, blue, and green are two-dimensionally arranged on a transparent substrate. It is also possible to apply so as to cover the surface. Here, covering the pixel means that the pixel is formed closer to the liquid crystal layer than the pixel, and the pixel and the retardation film made of the above resin composition may be in direct contact with each other. Not necessary. For example, when the color filter substrate has an overcoat layer for flatness, the retardation film made of the above resin composition can be formed on the liquid crystal layer side of the overcoat layer. Yes, it can be formed on the substrate side of the overcoat layer. In addition, a retardation film made of the above resin composition is formed on a substrate, and a color filter for a liquid crystal display device in which pixels of each color of red, blue, and green are two-dimensionally arranged thereon is formed. It is also possible.

[0089] In addition, the above-mentioned resin composition contains coloring components such as pigments and dyes, which are used as varnishes for each color pixel of the color filter, and provide a retardation compensation function to each color pixel itself. It is also possible to do. When used for color pixels, the retardation R is adjusted so that the phase difference RZ λ is approximately the same as the main wavelength λ for each color pixel, that is, the red, green, and blue pixels. It is preferable for aligning the phase difference compensation effect in

[0090] The retardation film for a liquid crystal display device of the present invention is formed by applying a resin composition on a substrate and performing a heat treatment. The retardation film has a retardation, and has a function of correcting birefringence generated in the process of light passing through the liquid crystal layer in the liquid crystal display device. Since the molecular chain of polyimide resin is easily oriented parallel to the substrate surface, a difference in refractive index (birefringence as a film) occurs between the film thickness direction and the direction parallel to the film surface. In addition, since the molecular orientation in the film plane is random, there is no anisotropy of the refractive index in the direction parallel to the film plane. That is, when the retardation thin film of the present invention has the X-axis and y-axis in the in-plane direction and the z-axis in the direction perpendicular to the film surface, the refractive index in each direction of the thin film containing the polyimide-based resin is nx≥ny> nz, which is a retardation thin film (negative C plate) that has optically negative uniaxial anisotropy and whose optical axis is substantially perpendicular to the film surface. Here, optically negative uniaxial anisotropy means that the refractive index of the remaining one axis is small compared to the refractive index of the two axes that are equal to each other, and the optical axis is relative to the film surface. The term “substantially vertical” means that nx = ny> nz. Specifically, 0≤nx-ny≤0.005, ny> nz is sufficient.

 [0091] The birefringence Δη (= ηχ-ηζ) in the thickness direction of the retardation film is preferably 0.01 to 0.3. More preferably, it is 0.03 or more, and further preferably 0.05 or more. If the birefringence is less than 0.01, the thickness of the retardation film necessary to compensate for the phase difference of the liquid crystal becomes excessive, and film formation becomes difficult.

 [0092] The thickness of the retardation film is preferably 0.5 to 20 μm! /.

The retardation film of the present invention is generally effective for liquid crystal display devices. However, since the optical axis is substantially perpendicular to the retardation film surface, the liquid crystal molecules in the liquid crystal display device, particularly when no voltage is applied, to the liquid crystal cell surface. Display method in which liquid crystal molecules are aligned in a direction substantially parallel to the liquid crystal cell surface when a voltage is applied (specifically, MVA (Multi-domain Vertical Alignment) method). It is more preferably used in a liquid crystal display device of a vertical alignment method such as a PVA (Patterned Vertical Alignment) method or a CPA (Continuous Pinwheel Alignment) method. [0093] As described above, since the optical axis of the retardation film of the present invention is substantially perpendicular to the substrate surfaces of the two substrates sandwiching the liquid crystal, the retardation compensation effect is obtained when the screen is viewed vertically. However, in the case of the vertical alignment method, the phase difference of the liquid crystal layer is almost zero in the vertical direction when no voltage is applied, so that compensation for the phase difference is not necessary. That is, when no voltage is applied, good black display can be obtained without compensating for the phase difference. However, in the oblique direction, there is a phase difference in the liquid crystal layer even when no voltage is applied. Therefore, if this phase difference is not compensated for, light leakage occurs, and a good black display cannot be obtained, resulting in a decrease in contrast. Therefore, the retardation film of the present invention has a remarkable effect in improving the contrast in the oblique direction and thus in widening the viewing angle in the vertical alignment method.

 Example

 [0094] <Measurement of reduced viscosity (η sp / C) of polyimide precursor>

 A solution obtained by dissolving and diluting the polyimide precursor with N-methylpyrrolidone to a concentration of 0.5 gZdl was measured at 30 ° C. using an Ubbelohde viscometer.

[0095] <Optical axis measurement method>

 It was measured using “OPTIPRO” manufactured by Shintech.

 After applying the polyimide precursor solution on a glass substrate with a spinner so that the finished thickness is 2.0 m, it is dried at 120 ° C for 20 minutes and then at 240 ° C for 30 minutes or 270 ° C for 40 minutes. A polyimide resin thin film was obtained by heat treatment. The refractive index anisotropy in the direction parallel to the film surface of this polyimide resin thin film and the refractive index anisotropy in the direction perpendicular to the film surface were measured.

<Measurement method of birefringence>

 Measurement was performed using "Prism Coupler 2010" manufactured by Metricon.

After applying the polyimide precursor solution on a glass substrate with a spinner so that the finished thickness is 2.0 m, it is dried at 120 ° C for 20 minutes and then at 240 ° C for 30 minutes or 270 ° C for 40 minutes. A polyimide resin thin film was obtained by heat treatment. The refractive index nl (= nx) in the direction parallel to the film surface of this polyimide resin thin film and the refractive index n2 (= nz) in the film thickness direction are measured, and the differential birefringence of these refractive indexes is calculated by the following equation. did. A 63.8nm HeNe laser was used as the light source. Δ η = η1— n2

 [0096] <Measurement Method of Film Coloring>

 Measurements were made using an "MCPD-2000" microspectrophotometer manufactured by Otsuka Electronics Co., Ltd. After applying the polyimide precursor solution on a glass substrate with a spinner so that the finished thickness is 2.0 m, it is dried at 120 ° C for 20 minutes and then at 240 ° C for 30 minutes or 270 ° C for 40 minutes. A polyimide resin thin film was obtained by heat treatment. In the XYZ color system (CIE1931 standard color system), the color coordinates (X, y) = (0.3100, 0.3162) of the standard C light source and the color coordinates of light after passing through the polyimide resin film (xl , yl) and the difference (Δχ, Ay). Here, Δ x = xl—x and Ay = yl—y. When both Δχ and Ay are large, the white display is yellowish and the display quality is degraded. Both Δχ and Ay are preferably 0.005 or less, and more preferably 0.003 or less.

 [0097] Synthesis Example (Synthesis of 1,2,3,4-cyclobutanetetracarboxylic dianhydride)

 A 2 liter internal-irradiation glass reaction flask equipped with a Neurex (registered trademark) glass water-cooled lamp jacket was charged with 255 g (2.60 mol) maleic anhydride and 1,445 g ethyl acetate, and the flask was filled with nitrogen. Then, the solution was stirred and dissolved at room temperature. The reaction solution was cooled to 5 ° C with continuous stirring, and then irradiation with a 400 W high-pressure mercury lamp was started and light irradiation was continued for 96 hours. During the irradiation, the reaction solution temperature was kept at 3-5 ° C. After completion of the reaction, the crystals and the filtrate were separated by filtration. The crude crystals were washed with ethyl acetate and then dried in a vacuum dryer at 40 ° C. for 10 hours to obtain 194 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride crystals.

 [0098] Example 1

Trans- 1,4-diaminocyclohexane 10.96 g (0.096 mol) and bis (3-aminopropyl) tetramethyldisiloxane 0.99 g (0.004 mol) in N-methyl under a dry nitrogen stream 2-Pyrrolidone was dissolved in 177.28 g. Then, 3, 3, 4, 4, 4—biphenyltetra-force 28.25 g (0.096 mol) of rubonic dianhydride and 40. OOg of N-methyl-2-pyrrolidone were added at 60 ° C. Stir for hours. Further, 1.18 g (0.008 mol) of phthalic anhydride was added and stirred at 60 ° C. for 3 hours to obtain a transparent and viscous polyamic acid solution A (polymer concentration: 16% by weight). The viscosity of Solution A measured at 25 ° C. was 830 mPa's. Reduced viscosity is 0.70dl / g.

 [0099] Polyamic acid solution A was applied on a glass substrate to a thickness of 2.0 m with a spinner, dried at 120 ° C for 20 minutes, and further heat-treated to obtain a polyimide resin film. Got. The refractive index anisotropy in the direction parallel to the film surface of the polyimide resin thin film after heat treatment at 240 ° C for 30 minutes was nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was shown. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. The refractive index in the direction parallel to the film surface of the polyimide resin thin film was nl = l.683, the refractive index in the film thickness direction was n2 = l.592, and the birefringence was Δη = 0.091. The color coordinates of transmitted light are (0.3108, 0.3172), Δχ = 0.0008, Δγ = 0.0010, both Δχ and Ay are 0.003 or less, and there is no phase difference thin film. was gotten. The polyimide resin thin film after heat treatment at 270 ° C. for 40 minutes had a refractive index anisotropy in the direction parallel to the film surface of nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was shown. That is, the obtained polyimide resin thin film had optically negative-axis anisotropy and the optical axis was substantially perpendicular to the thin film surface. The refractive index nl = l. 745 and n2 = l. 571 in the direction parallel to the film surface of the polyimide resin thin film are also birefringent Δη = 0.174, and the transmitted light color coordinates (0.3116, 0. 3179) The forces were also Δχ = 0.0016 and Δγ = 0.0017, both Δχ and Ay were 0.003 or less, and a phase difference thin film without coloring was obtained.

 [0100] Example 2

 Trans- 1,4 diaminocyclohexane 10.96 g (0.096 mol) and bis (3aminopropyl) tetramethyldisiloxane 0.99 g (0.004 mol) in N-methyl-2-pyrrolidone under a dry nitrogen stream 173. Dissolved in 28 g. After that, 3, 3, 4, 4, 4-biphenyltetra-force rubonic acid dianhydride 25.30g (0.086 mole), pyromellitic anhydride 2.18g (0.010 mole) and N-methyl-2-pyrrolidone 40.00 g was added and stirred at 60 ° C for 3 hours. Further, 1.18 g (0.008 mol) of phthalic anhydride was added, followed by stirring at 60 ° C. for 3 hours to obtain a transparent and viscous polyamic acid solution B (polymer concentration: 16% by weight). The viscosity of Solution B measured at 25 ° C was 69 OmPa's. The reduced viscosity was 0.67 dlZg.

[0101] Fabricated in the same manner as in Example 1, and heat-treated at 270 ° C for 40 minutes on the polyimide resin thin film surface The refractive index anisotropy in the parallel direction was nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was exhibited. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. The refractive index in the direction parallel to the film surface of the polyimide resin thin film is nl = l. 698, the refractive index in the film thickness direction is n2 = l. 586, the birefringence is Δη = 0.112, and the color coordinates of the transmitted light (0. 31 11, 0. 3174), Δχ = 0.0011, Δγ = 0.0012, and Δχ and Ay were both 0.003 or less, and a phase difference thin film without coloring was obtained.

[0102] Example 3

 Trans- 1,4-diaminocyclohexane 10.96 g (0.096 mol) and bis (3-aminopropyl) tetramethyldisiloxane 0.99 g (0.004 mol) in N-methyl under a dry nitrogen stream 2-pyrrolidone was dissolved in 171.06 g. Then, 3, 3 ,, 4, 4, -biphenyltetra-force rubonic acid dianhydride 28.25g (0.096 mol) and N-methyl-2-pyrrolidone 40.OOg were calored and heated at 60 ° C. The mixture was stirred for a time to obtain a transparent and viscous polyamic acid solution C (polymer concentration: 16% by weight). The viscosity of Solution C measured at 25 ° C was 5,222 mPa's. The reduced viscosity was 0.81 dlZg.

 [0103] The refractive index in the direction parallel to the film surface of the polyimide resin thin film prepared in the same manner as in Example 1 and heat-treated at 240 ° C for 30 minutes is nl = l. 706, and the refractive index in the film thickness direction is n2 = l. 592, birefringence up to Δη = 0.114, color coordinates of transmitted light up to ί (0 3109, 0. 3171), Δχ = 0. 0009, Δγ = 0. 0009, Δχ, Ay Both were 0.003 or less, and there was no coloration! In addition, the polyimide resin thin film after heat treatment at 270 ° C. for 40 minutes had a refractive index anisotropy in the direction parallel to the film surface of nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was shown. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. Refractive index in the direction parallel to the film surface of polyimide resin thin film nl = l. 735, n2 = l. 572 Force birefringence Δη = 0.163, and transmitted light color coordinates (0.33116, 0.33180) ) Force et al. Δχ = 0.0016, Δγ = 0.0018, and Δχ and Ay were both 0.003 or less, and there was no coloring!

[0104] Example 4 Under a dry nitrogen stream, 11.42 g (0.100 mol) of trans-1,4 diaminocyclohexane was dissolved in 174.42 g of N-methylol-2-pyrrolidone. Then, 3, 3 ', 4, 4, 1-biphenyltetracarboxylic dianhydride 29.42g (0.100mol) and N-methyl-2-pyrrolidone 40.00g were added and stirred at 60 ° C for 5 hours. . After cooling to room temperature, 85.07 g of N-methyl-2 pyrrolidone was added to obtain a transparent and viscous polyamic acid solution D (polymer concentration: 12% by weight). The viscosity of Solution D measured at 25 ° C was 5,878 mPa's. Reduced viscosity is 1.68dl / g, 7 pieces.

 [0105] The refractive index anisotropy in the direction parallel to the film surface of the polyimide resin thin film prepared in the same manner as in Example 1 and heat-treated at 270 ° C for 40 minutes was nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was exhibited. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. The refractive index in the direction parallel to the film surface of the polyimide resin thin film is nl = l.745, the refractive index in the film thickness direction is n2 = l.571, the birefringence is Δη = 0.174, the color of the transmitted light The coordinates are (0.31 20, 0. 3187), Δχ = 0.0020, Δγ = 0.0025, both Δχ, Ay are 0.003 or less, and a phase difference thin film without coloring was obtained. .

 [0106] Example 5

 Under a stream of dry nitrogen, 11.42 g (0.100 mol) of trans-1,4 diaminocyclohexane was dissolved in 176.30 g of N-methyl-2-pyrrolidone. Thereafter, 29.78 g (0.096 mol) of 4,4′-oxydiphthalic dianhydride and 40.00 g of N-methyl-2-pyrrolidone were added and stirred at 60 ° C. for 5 hours. After cooling to room temperature, 85.83 g of N-methyl-2 pyrrolidone was obtained to obtain a transparent and viscous polyamic acid solution E (polymer concentration: 12% by weight). The viscosity of Solution E measured at 25 ° C was 1,139 mPa's. The reduced viscosity was 0.96 dlZg.

[0107] The refractive index anisotropy in the direction parallel to the film surface of the polyimide resin thin film produced in the same manner as in Example 1 and heat-treated at 270 ° C for 40 minutes was nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was exhibited. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. The refractive index in the direction parallel to the film surface of the polyimide resin thin film is nl = l. 631, the refractive index in the film thickness direction is n2 = l. 616, the birefringence is Δη = 0.015, the color of the transmitted light The coordinates are (0.31 22, 0.3190), Δχ = 0.0022, Δγ = 0.0028, and Δχ and Ay were both 0.003 or less, and a phase difference thin film without coloring was obtained.

[0108] Example 6

 P-Phenylenediamine 10.38 g (0.096 mol) and bis (3 aminopropyl) tetramethyldisiloxane 0.99 g (0.004 mol) to 24.79 g of N-methyl-2-pyrrolidone 1 under dry nitrogen flow Dissolved. Then, 1, 2, 3, 4-cyclobutanetetracarboxylic dianhydride 1 8.83 g (0.096 mol) and N-methyl-2 pyrrolidone 40.00 g were added. Stir at C for 3 hours. Further, 1.18 g (0.008 mol) of phthalic anhydride was added and stirred at 60 ° C. for 3 hours to obtain a transparent and viscous polyamic acid solution F (polymer concentration: 16% by weight). The viscosity of Solution F measured at 25 ° C was 384 mPa's. The reduced viscosity was 0.56 dlZg.

 [0109] The refractive index in the direction parallel to the film surface of the polyimide resin thin film prepared in the same manner as in Example 1 and heat-treated at 240 ° C for 30 minutes is nl = l. 621, and the refractive index in the film thickness direction is n2 = l. 586, birefringence ί or Δη = 0.035. Also, the color coordinates of transmitted light are ί (0.3109, 0.3173), Δχ = 0.0009, Δγ = 0.0011, Δχ, Ay are both 0.005 or less, A thin retardation film was obtained. In addition, the polyimide resin thin film after heat treatment at 270 ° C. for 40 minutes had a refractive index anisotropy in the direction parallel to the film surface of nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was shown. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. The refractive index in the direction parallel to the film surface of the polyimide resin thin film nl = l. 631, n2 = l. 586 also has birefringence Δη = 0.045, and the transmitted light color coordinates (0.3127, 0. 3 197) Force et al. Δχ = 0.0027, Δγ = 0.0035, Δχ and Ay were both 0.005 or less, and a retardation film with small coloring was obtained.

 [0110] Example 7

Under a nitrogen stream, 4,82-diaminobenzanilide 21.82g (0.096 monole) and bis (3-aminopropyl) tetramethyldisiloxane 0.99g (0.004mol) into γ-butyrolacton 112.41g Dissolved. Next, 72.41 g of N-methyl-2 pyrrolidone was added. Thereafter, 18.83 g (0.096 mol) of 1,2,3,4 tetracyclobutanetetracarboxylic dianhydride and 40.00 g of N-methyl-2-pyrrolidone were added and stirred at 60 ° C. for 3 hours. In addition, anhydrous phthalate After adding 1.18 g (0.008 mol) of acid, the mixture was stirred at 60 ° C. for 3 hours to obtain a transparent and viscous polyamic acid solution G (polymer concentration: 16% by weight). The viscosity of Solution G measured at 25 ° C was 1,08 OmPa's. The reduced viscosity was 0.71 dlZg.

 [0111] The refractive index anisotropy in the direction parallel to the film surface of the polyimide resin thin film produced in the same manner as in Example 1 and heat-treated at 240 ° C for 30 minutes was nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was exhibited. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. The refractive index in the direction parallel to the film surface of the polyimide resin thin film is nl = l. 669, the refractive index in the film thickness direction is n2 = l. 604, and the birefringence is about Δη = 0.065, the transmitted light Color coordinates ί (0. 31 15, 0. 3180), Δχ = 0.0015, Δγ = 0.0018, and Δχ and Ay are both 0.003 or less, and a phase difference thin film without coloring was obtained. . Further, the polyimide resin thin film when heat-treated at 270 ° C. for 40 minutes had a refractive index anisotropy in the direction parallel to the film surface of nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was shown. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. The refractive index nl = l. 688 and n2 = l. 601 in the direction parallel to the film surface of the polyimide resin thin film are also birefringent Δη = 0.087, and the transmitted light color coordinates (0.3142, 0. 3212) Force et al. Δχ = 0.0042, Δγ = 0.0050, and Δχ and Ay were both 0.005 or less, and a retardation film with small coloring was obtained.

 [0112] Example 8

 In a dry nitrogen stream, 2,38-dimethylbenzidine (20.38 g, 0.096 mol) and bis (3-aminopropyl) tetramethyldisiloxane (0.99 g, 0.004 mol) were added to N-methyl-2-pyrrolidone. Dissolved in 28 g. Then, add 1,83,83 g (0.096 mol) of 1,2,3,4 tetracyclobutanetetracarboxylic acid dianhydride and 40.OOg of N-methyl-2-pyrrolidone. Stir at C for 3 hours. Further, 1.18 g (0.008 mol) of phthalic anhydride was added and stirred at 60 ° C. for 3 hours to obtain a transparent and viscous polyamic acid solution H (polymer concentration: 16% by weight). The viscosity of solution H measured at 25 ° C. was 1, 055 mPa's. Reduced viscosity was 0.78 dlZg o

[0113] On the film surface of a polyimide resin thin film prepared in the same manner as in Example 1 and heat-treated at 240 ° C for 30 minutes. The refractive index in the parallel direction is nl = l. 625, the refractive index in the film thickness direction is n2 = l. 587, birefringence is up to Δη = 0.038, and the color coordinate of transmitted light is up to 0.33, 0.3180), Δχ = 0.0014, Δγ = 0.0018, Δχ and Ay were both 0.003 or less, and no coloring was observed! In addition, the polyimide resin thin film after heat treatment at 270 ° C. for 40 minutes had a refractive index anisotropy in the direction parallel to the film surface of nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was shown. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. Refractive index nl = l. 625, n2 = l. 586 Force birefringence Δη = 0.039, and the color coordinates of transmitted light (0.33134, 0.33210) ) Force et al. Δχ = 0.0034, Δγ = 0.0048, and Δχ and Ay were both 0.005 or less, and a colored / J, dilute phase difference thin film was obtained.

[0114] Example 9

 In a dry nitrogen stream, 2,74-bis (trifluoromethyl) benzidine (30.74 g, 0.096 mole) and bis (3-aminopropyl) tetramethyldisiloxane (0.99 g, 0.004 mole) were mixed with N. —Methyl-2-pyrrolidone 231. Dissolved in 69 g. Then, 1, 2, 3, 4-cyclobutanetetracarboxylic dianhydride 18.83 g (0.096 mol) and N-methyl-2-pyrrolidone 40.OOg were added and stirred at 60 ° C for 3 hours. Further, 1.18 g (0.008 mol) of phthalic anhydride was added and stirred at 60 ° C. for 3 hours to obtain a transparent and viscous polyamic acid solution 1 (polymer concentration: 16% by weight). The viscosity of Solution I measured at 25 ° C was 275 mPa's. The reduced viscosity is 0.58 dl / g.

[0115] The refractive index in the direction parallel to the film surface of the polyimide resin thin film prepared in the same manner as in Example 1 and heat-treated at 240 ° C for 30 minutes is nl = l. 560, and the refractive index in the film thickness direction is n2 = l. 540, birefringence up to Δη = 0.020, transmitted light color coordinates up to 0 (0.3103, 0.33164), Δχ = 0.0003, Δγ = 0.0002, Δχ, Ay Both were 0.003 or less, and there was no coloration! In addition, the polyimide resin thin film after heat treatment at 270 ° C. for 40 minutes had a refractive index anisotropy in the direction parallel to the film surface of nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was shown. That is, the obtained polyimide resin thin film has optically negative uniaxial anisotropy and the optical axis is substantially perpendicular to the thin film surface. I got it. Refractive index in the direction parallel to the film surface of polyimide resin thin film nl = l. 559, n2 = l. 541 Force birefringence Δη = 0.018, and transmitted light color coordinates (0.3108, 0.371) ) Force et al. Δχ = 0.0008, Δγ = 0.0009, and Δχ and Ay were both 0.003 or less, and there was no coloring!

[0116] Example 10

 In a dry nitrogen stream, 4,22-diaminodiphenyl 19.22 g (0.096 mol) and bis (3-aminopropyl) tetramethyldisiloxane 0.99 g (0.004 mol) were mixed with N-methyl-2. —Pyrrolidone 171. Dissolved in 21 g. Thereafter, 18.83 g (0.096 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 40.OO g of N-methyl-2-pyrrolidone were added, and the mixture was stirred at 60 ° C. for 3 hours. Further, 1.18 g (0.008 mol) of phthalic anhydride was added and stirred at 60 ° C. for 3 hours to obtain a transparent and viscous polyamic acid solution (polymer concentration: 16% by weight). The viscosity of Solution J measured at 25 ° C. was 258 mPa's. Reduced viscosity is 0.556dlZg.

[0117] The refractive index anisotropy in the direction parallel to the film surface of the polyimide resin thin film produced in the same manner as in Example 1 and heat-treated at 240 ° C for 30 minutes was nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was exhibited. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. Nl = l. 620 in the direction parallel to the film surface of the polyimide resin thin film, the refractive index in the film thickness direction is up to n2 = l. 608, birefringence up to Δη = 0.013, color coordinates of transmitted light (0.3111, 0.3178), Δχ = 0.0011, Δγ = 0.0016, and Δχ and Ay were both 0.003 or less, and a phase difference thin film without coloring was obtained. The polyimide resin thin film after heat treatment at 270 ° C. for 40 minutes had a refractive index anisotropy in the direction parallel to the film surface of nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, it was nx> nz and showed negative uniaxiality. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. The refractive index in the direction parallel to the film surface of the polyimide resin thin film nl = 1. 622, n2 = l. 607 is also birefringence Δη = 0.015, and the transmitted light color coordinates (0.312 7, 0. 3197) Force et al. Δχ = 0.0027, Δγ = 0.0035, Δχ and Ay were both 0.005 or less, and a retardation film with small coloring was obtained. [0118] Example 11

 Under a stream of dry nitrogen, 10.81 g (0.100 mol) of p-phenylenediamine was dissolved in 132.41 g of N-methyl-2-pyrrolidone. Thereafter, 19.61 g (0.100 mol) of 1, 2, 3, 4 cyclobutanetetracarboxylic dianhydride and 40.00 g of N-methyl-2-pyrrolidone were added, and the mixture was stirred at 60 ° C. for 4 hours. A transparent and viscous polyamic acid solution K (polymer concentration 15% by weight) was obtained. The viscosity of solution K measured at 25 ° C was 9,257 mPa's. The reduced viscosity was 1.36 dlZg.

 [0119] The refractive index anisotropy in the direction parallel to the film surface of the polyimide resin thin film prepared in the same manner as in Example 1 and heat-treated at 240 ° C for 30 minutes was nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was exhibited. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. The refractive index in the direction parallel to the film surface of the polyimide resin thin film was nl = l.635, the refractive index in the film thickness direction was n2 = l.584, and the birefringence was Δη = 0.051. In addition, the color coordinates of transmitted light are (0.3116, 0.3182), Δχ = 0.0016, Δγ = 0.0020, and Δχ and Ay are both 0.003 or less, and there is no coloring retardation film. was gotten.

 [0120] Example 12

 Under a nitrogen stream, 22.73 g (0.100 mol) of 4,4′-diaminobenza-lide was dissolved in 111.14 g of γ-butyroratatone. Next, 71.14 g of Ν-methyl 2 pyrrolidone was added. Thereafter, 19.61 g (0.100 mol) of 1, 2, 3, 4 cyclobutanetetracarboxylic dianhydride and 40.00 g of N-methyl-2-pyrrolidone were added, and the mixture was stirred at 60 ° C. for 4 hours. A transparent and viscous polyamic acid solution L (polymer concentration 16% by weight) was obtained. The viscosity of Solution L measured at 25 ° C was 31,400 mPa's. The reduced viscosity was 1.81 dlZg.

[0121] The refractive index anisotropy in the direction parallel to the film surface of the polyimide resin thin film produced in the same manner as in Example 1 and heat-treated at 240 ° C for 30 minutes was nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was exhibited. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. The refractive index in the direction parallel to the film surface of the polyimide resin thin film is nl = l. 685, the refractive index in the film thickness direction is n2 = l. 598, the birefringence is Δη = 0.087, and the color coordinates of the transmitted light Is (0.31 31, 0.3204), Δχ = 0.0031, Δγ = 0.0042, and Δχ and Ay were both 0.005 or less, and a retardation film with small coloring was obtained.

[0122] Comparative Example 1

 Under a dry nitrogen stream, 3,92'-diaminodiphenylsulfone 11.92 g (0.048 mol), p-phenoldiamine 5.19 g (0.048 mol) and bis (3-aminopropyl) tetramethyldisiloxane 99 g (0.004 mol) was dissolved in 209.55 g of N-methyl-2 pyrrolidone. After that, 3, 3 ', 4, 4,-biphenyltetracarboxylic dianhydride 28.25g (0.096 mol) and N-methyl 2 pyrrolidone 40.00g were added at 60 ° C. Stir for 3 hours. Further, 1.18 g (0.008 mol) of phthalic anhydride was added and stirred at 60 ° C. for 3 hours to obtain a transparent and viscous polyamic acid solution M (polymer concentration: 16% by weight). It was. The viscosity of Solution M measured at 25 ° C. was 94 OmPa's. The reduced viscosity was 0.64 dlZg.

 [0123] The refractive index anisotropy in the direction parallel to the film surface of the polyimide resin thin film prepared in the same manner as in Example 1 and heat-treated at 270 ° C for 40 minutes was nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was shown. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. The refractive index in the direction parallel to the film surface of the polyimide resin thin film is nl = l.754, the refractive index in the film thickness direction is n2 = l.663, the birefringence is Δη = 0.091, the color of the transmitted light The coordinates were (0.3170, 0.3272), Δχ = 0.0070, Δγ = 0.0110, and both Δχ and Ay were retardation films colored yellow that was larger than 0.005.

 [0124] Comparative Example 2

 Under a dry nitrogen stream, 10.38 g (0.096 mol) of P-phenylenediamine and 0.99 g (0.004 mol) of bis (3 aminopropyl) tetramethyldisiloxane were converted to 74.23 g of N-methyl-2-pyrrolidone. Dissolved. Subsequently, 3,3 ′, 4,4, -biphenyltetracarboxylic dianhydride (28.25 g, 0.096 mol) and N-methyl-2-pyrrolidone (40.00 g) were added. Stir at C for 3 hours. Further, 1.18 g (0.008 mol) of phthalic anhydride was added and stirred at 60 ° C. for 3 hours to obtain a transparent and viscous polyamic acid solution N (polymer concentration: 16% by weight). The viscosity of Solution N measured at 25 ° C was 664 mPa's. The reduced viscosity was 0.66 dlZg.

[0125] Prepared in the same manner as in Example 1, and heat-treated at 240 ° C for 30 minutes. The refractive index anisotropy in the parallel direction was nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was exhibited. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. The refractive index in the direction parallel to the film surface of the polyimide resin thin film is nl = l. 810, the refractive index in the film thickness direction is n2 = l. 621, the birefringence is Δη = 0.189, and the color coordinates of the transmitted light (0.331 95, 0.3327), Δχ = 0.0095, Δγ = 0.0165, and both Δχ and Ay were retardation films colored yellow that was larger than 0.005. In addition, the polyimide resin film after heat treatment at 270 ° C for 40 minutes has a refractive index nl = l. 831, n2 = l. 616 and birefringence Δη = 0.215, and the transmitted light color coordinates (0 3206, 0. 3339) The forces were also Δχ = 0.106 and Δγ = 0.0177, and both Δχ and Ay were retardation films colored yellow that was larger than 0.005.

[0126] Comparative Example 3

 Under a dry nitrogen stream, 4,82-diaminobenzanilide (21.82g, 0.096 monole) and bis (3-aminopropyl) tetramethyldisiloxane (0.99g, 0.004mol) were converted to 137.14g of γ-butyrolacton. Dissolved. Next, 97.14 g of Ν-methyl-2 pyrrolidone was added. Then, 3, 3 ', 4, 4'-biphenyltetracarboxylic dianhydride 28.25g (0.096 mol) and N-methyl 2 pyrrolidone 40.OOg were added and kept at 60 ° C for 3 hours. Stir. Further, 1.18 g (0.008 mol) of phthalic anhydride was added, followed by stirring at 60 ° C. for 3 hours to obtain a transparent and viscous polyamic acid solution 0 (polymer concentration: 16% by weight). The viscosity of solution O measured at 25 ° C. was 5,878 mPa's. The reduced viscosity was 1.03 dlZg.

[0127] The refractive index anisotropy in the direction parallel to the film surface of the polyimide-based resin thin film prepared in the same manner as in Example 1 and heat-treated at 240 ° C for 30 minutes was nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was shown. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. The refractive index in the direction parallel to the film surface of the polyimide resin thin film is nl = l. 826, the refractive index in the film thickness direction is n2 = l. 610, the birefringence is Δη = 0.216, and the color of the transmitted light. The coordinates were (0.3260, 0.3450), Δχ = 0.0160, Δγ = 0.0288, and both Δχ and Ay were retardation films colored yellow that was larger than 0.005. In addition, the polyimide resin film after heat treatment at 270 ° C for 40 minutes has a refractive index nl = l. 838, n2 = l. 229, and the transmitted light color coordinate (0.3255, 0.3437) force is also Δχ = 0.0155, Δγ = 0.02 75, and both Δχ and Ay are colored yellow, which is larger than 0.005. It was a phase difference film.

[0128] Comparative Example 4

 Under a nitrogen stream, 10.81 g (0.100 mol) of P-phenylenediamine was dissolved in 92.92 g of N-methyl-2-pyrrolidone. Thereafter, 22.42 g (0.100 mol) of 1,2,4,5 cyclohexanetetracarboxylic dianhydride and 40.00 g of N-methyl-2-pyrrolidone were added and stirred at 60 ° C. for 4 hours. A transparent and viscous polyamic acid solution P (polymer concentration 20% by weight) was obtained. The viscosity of Solution P measured at 25 ° C was 350 mPa's. Reduced viscosity is 0.30dl / g.

 [0129] The refractive index anisotropy in the direction parallel to the film surface of the polyimide resin thin film produced in the same manner as in Example 1 and heat-treated at 240 ° C for 30 minutes was nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was exhibited. That is, the obtained polyimide resin thin film had optically negative uniaxial anisotropy and the optical axis was substantially perpendicular to the thin film surface. The refractive index in the direction parallel to the film surface of the polyimide resin thin film is nl = l. 600, the refractive index in the film thickness direction is ί n2 = l. 598, and the birefringence is Δ or η = 0.002 in the transmitted light. The color coordinates are ί (0. 31 11, 0. 3173), Δχ = 0.0011, Δγ = 0.0011, both Δχ, Ay are 0.003 or less, and the phase difference thin film is not colored. Birefringence was not enough.

 [0130] Comparative Example 5

 Under a nitrogen stream, 22.73 g (0.100 mol) of 4,4′-diaminobenza-lide was dissolved in 90.29 g of γ-butyroratatone. Next, 50.29 g of Ν-methyl 2 pyrrolidone was added. Then, 1, 2, 4, 5 cyclohexane tetracarboxylic dianhydride 22.42g (0. 100 mol) and N-methyl-2pyrrolidone 40.00g were added and stirred at 60 ° C for 4 hours. . A clear viscous polyamic acid solution Q (polymer concentration 20% by weight) was obtained. The viscosity of Solution O measured at 25 ° C was 209 mPa's. The reduced viscosity was 0.24 dlZg.

[0131] The refractive index anisotropy in the direction parallel to the film surface of the polyimide-based resin thin film prepared in the same manner as in Example 1 and heat-treated at 240 ° C for 30 minutes was nx = ny. When the refractive index anisotropy in the direction perpendicular to the film surface was measured, nx> nz and negative uniaxiality was shown. That is, the obtained polyimide resin thin film has optically negative uniaxial anisotropy and the optical axis is substantially perpendicular to the thin film surface. Met. The refractive index in the direction parallel to the film surface of the polyimide resin thin film is nl = l.638, the refractive index in the film thickness direction is n2 = l.632, the birefringence is Δη = 0.006, the color of the transmitted light Coordinates are (0.33114, 0.3178), Δχ = 0.0014, Δγ = 0.0016, both Δχ, Ay are 0.003 or less, and it is a non-colored retardation film, but it is birefringent. There was not enough power.

[0132] Example 13

 A method for producing a color filter having a retardation film is described below.

 <Production of black matrix>

 In γ-butyrate ratatone (3825 g) solvent, pyromellitic anhydride (149.6 g), benzophenone tetracarboxylic dianhydride (225. 5 g), 3, 3, -diaminodiphenylsulfone (69.5 g), After reacting 4,4,1-diaminodiphenyl ether (210.2 g) and bis (3aminopropyl) tetramethyldisiloxane (17.4 g) at 60 ° C for 3 hours, maleic anhydride (2.25 g) was added. The mixture was further reacted at 60 ° C for 1 hour to obtain a polyamic acid solution (polymer concentration: 15% by weight).

 [0133] Carbon black (MA-77 manufactured by Mitsubishi Chemical Co., Ltd.) 7. 3 g, 44.8 g of the above polyamic acid solution with a polymer concentration of 15% by weight, 35 g of N-methyl-2-pyrrolidone, 3-methyl 3-methoxyacetate 12 Using a homogenizer with 9 g of glass beads and 100 g of glass beads, the glass beads were removed by filtration at 7000 rpm for 30 minutes, and a pigment dispersion with a pigment concentration of 14% by weight was obtained. The primary particle size of the carbon black used was 23 nm. At this time, the weight ratio of the carbon black Z polyamic acid compound was 52Z48.

[0134] To 57.2 g of the pigment dispersion, 36.4 g of N-methyl-2-pyrrolidone and 6.4 g of 3-methoxy-1-3-methyl-butyl acetate were added and mixed to prepare a black paste. After applying this paste on an alkali-free glass substrate, pre-beta treatment was performed at 130 ° C. to form a black colored film of polyamic acid. Next, a positive type photoresist was applied and dried by heating at 90 ° C. to form a photoresist film. This was exposed through a photomask using an ultraviolet exposure machine. After exposure, the film was immersed in an alkali developer, and the photoresist was developed and the polyamic acid black colored film was etched simultaneously to form openings. After etching, the unnecessary photoresist layer was peeled off with ethylene glycol monomethyl acetate. The etched polyamic acid black colored film is heated to 290 ° C and cured, and polyimide resin black mat Ricks formed.

 [0135] <Fabrication of pixels>

 In γ-butyrolatatone, pyromellitic anhydride (0.49 molar equivalent), benzophenone tetra force rubonic acid dianhydride (0.50 molar equivalent), and 4,4, -diaminodiphenyl ether (0.75 molar equivalent) 3, 3, 1-diaminodiphenyl sulfone (0.20 molar equivalent), bis- (3-aminopropyl) tetramethyldisiloxane (0.05 molar equivalent), and maleic anhydride (0.02 molar equivalent) To obtain a polyamic acid solution (polymer concentration 20% by weight).

 [0136] 200 g of this polyamic acid solution was taken out, and 136 g of γ-butyrate rataton and 64 g of ethylene glycol butyl ether were added thereto to obtain a polyamic acid solution for a pixel having a polymer concentration of 10% by weight.

[0137] _Pigment Red 177 (Anthraquinone Red) 4g, _Ύ-Butaguchi Rataton 40g, Ethylene glycol butyl ether 6g together with 100g of glass beads and dispersed at 7000rpm for 30 minutes, glass beads are removed by filtration Thus, a pigment dispersion having a pigment concentration of 8% by weight was obtained.

 [0138] To 30 g of the pigment dispersion, 30 g of the above polyamic acid solution for a pixel having a polymer concentration of 10% by weight was added and mixed to obtain a red color paste.

 [0139] A red paste was applied on a substrate on which a black resin black matrix was formed, and pre-beta treatment was performed to form a polyamic acid red colored film. Using a photoresist, red pixels were formed by the same means as described above, and heated to 290 ° C. for thermal curing.

 [0140] Pigment Green 7 (Phthalocyanine Green) 3.6 g, Pigment Yellow 83 (Benzidine Yellow) 0.4 g, γ-Butyl Ratatone 32 g, Ethylene Glyco-Lebutinoleate Tenole 4 g with Glass Beads 120 g at 7000 rpm After 30 minutes of dispersion treatment, the glass beads were removed by filtration to obtain a pigment dispersion having a pigment concentration of 10% by weight.

 [0141] To 32 g of the pigment dispersion, 30 g of the polyamic acid solution for pixels having a polymer concentration of 10% by weight was added and mixed to obtain a green color paste.

[0142] In the same manner as in the case of using the red paste, a green color paste was used to form a green pixel, which was then heated to 290 ° C and thermally cured. [0143] and the pixel for the polyamic acid solution 60g of the polymer concentration of 10 wt _^0/0, Pigment Blue 1 5 (Futaroshia - Nburu) 2. 8 g, N-methyl-2-pyrrolidone 30g, glass beads 150g of ethylene glycol butyl ether 10g And a homogenizer for 30 minutes at 7000 rpm for dispersion treatment, and then the glass beads were removed by filtration to obtain a blue color paste.

[0144] According to the same procedure as described above, a blue color paste was used to form a blue pixel, and heat curing was performed by heating to 290 ° C.

 [0145] A color filter was produced in this manner.

 Next, 0.25 g of the surfactant “Disparon” LC951 (manufactured by Enomoto Ichinari) was added to 187.5 g of the polyamic acid solution A (polymer concentration 16 wt%) prepared in Example 1, N-methyl 2 —Pyrrolidone 218.3 g, 3-methoxy-1-3-methyl 1-butanol 94. Og was added to prepare a coating solution having a polymer concentration of 6% by weight. The film is coated on the surface of the color filter substrate by the slit die coating method, dried at 120 ° C for 10 minutes, and then heat-treated at 270 ° C for 40 minutes. A polyimide thin film was formed on the color filter. The birefringence of this polyimide thin film is Δη = 0.174. Therefore, according to the above method, the retardation is 209 nm, the optical axis is perpendicular to the thin film, and the phase difference has an optically negative refractive index anisotropy. It was possible to obtain a color filter having a thin film.

 [0146] Example 14

 A polyimide thin film was formed on the color filter in the same manner as in Example 13 except that the polyamic acid solution F (polymer concentration: 16% by weight) prepared in Example 6 was used. This polyimide thin film has a film thickness of 4.4 / ζ πι and birefringence of Δη = 0.045. Therefore, the retardation is Sl98 nm, and the optical axis is perpendicular to the thin film. A color filter having an anisotropic retardation film could be obtained.

[0147] Example 15

Polyamic acid solution K prepared in Example 11 (polymer concentration 15% by weight) 200. Og, 0.25 g of surfactant “Disparon” LC951 (manufactured by Enomoto Isei), N-methyl-2 pip Lidon 205.8 g, 3-methoxy-1-methyl 1-butanol 94. Add Og, polymer A coating solution having a concentration of 6% by weight was prepared. As in Example 13, the color filter substrate was coated on the surface on which the pixels were formed by the slit die coating method, dried at 120 ° C for 10 minutes, and then heat treated at 240 ° C for 30 minutes to obtain a film thickness of 4. A 0 m polyimide film was formed on the color filter. The birefringence of this polyimide thin film is Δη = 0.051, and therefore, a color filter having a retardation film having an optically negative refractive index anisotropy with a retardation of 204 nm and an optical axis perpendicular to the thin film. Could get.

[0148] Example 16

 <Production and evaluation of color liquid crystal display elements>

 A transparent electrode made of indium oxide was formed on the color filter with a retardation film produced in Example 13. Separately, a substrate in which TFT elements, pixel electrodes, reflectors, etc. were formed on alkali-free glass was prepared as a counter substrate.

 [0149] After that, on each transparent electrode of the substrate, stripe-like projections made of polyimide were formed by photolithography, and then a vertical alignment film was provided. The cross section of the protrusion was trapezoidal and the height was about 1.5 m. However, the positions of the stripe protrusions were determined so that the stripe protrusions were alternately arranged with the opposing stripe protrusions when the color filter substrate and the TFT substrate were bonded together. After applying the end portions of the two substrates with a sealant and bonding them together, the n-type liquid crystal was filled and sealed between the cells, and polarizing plates were placed in front of and behind the cells so as to be cross-cold. In this way, a test liquid crystal display device (sample A) simulating the MVA (Multi-domain Vertical Alignment) method was fabricated. The cell electrode spacing was about 5 m using a bead spacer. In addition, a test liquid crystal display element (sample B) that differs only in that no polyimide retardation film was provided was prepared as a comparative product.

 [0150] Transmitted light with an applied voltage of 5 volts (on) and 0 volts (off) at an azimuth of 90 ° from the stripe direction of the protrusion and at a polar angle of 70 ° from the normal direction of the cell surface When the intensity ratio (contrast) was compared, the contrast in sample B was 8.3, whereas in sample A, the contrast improvement effect of 18 and the polyimide retardation film was recognized. In Sample A, a high-quality white display with a yellowish color was obtained.

 [0151] Example 17

Similar to Example 16 using the color filter with retardation film prepared in Example 14. Thus, a test liquid crystal display element (sample C) was produced. The transmitted light intensity ratio (contrast) of sample C was 18, and the effect of improving the contrast by the polyimide retardation film was recognized. A good white display without yellowing was also obtained.

[0152] Example 18

 A test liquid crystal display element (sample D) was produced in the same manner as in Example 16 using the color filter with a retardation film produced in Example 15. Sample D had a transmitted light intensity ratio (contrast) of 18, and the contrast enhancement effect of the polyimide retardation film was confirmed. A good white display without yellowing was also obtained.

[0153] Comparative Example 6

 A polyimide thin film was formed on the color filter in the same manner as in Example 13 except that the polyamic acid solution O (polymer concentration: 16% by weight) prepared in Comparative Example 3 was used. This polyimide thin film has a thickness of 0.9 / ζ πι and birefringence of Δη = 0.229. Therefore, the retardation is S206 nm, and the optical axis is perpendicular to the thin film. A color filter having an anisotropic retardation film was obtained.

 [0154] A test liquid crystal display element (sample E) was produced in the same manner as in Example 16 using the produced color filter with retardation film. Sample E had a transmitted light intensity ratio (contrast) of 15. However, the white display is yellowish and the image display quality is poor.

 [0155] Table 1 shows the results of Examples 1 to 12 and Comparative Examples 1 to 5. As shown in Table 1, in Examples 1 to 12, it can be seen that retardation films with little coloring and good birefringence are obtained. In Table 1, each abbreviation represents the following compound.

 [0156] BPDA: 3, 3, 4, 4, 4-biphenyltetracarboxylic dianhydride

 CBDA: 1, 2, 3, 4-cyclobutanetetracarboxylic dianhydride

 H-PMDA: 1, 2, 4, 5 Cyclohexanetetracarboxylic dianhydride

 ODPA: 4, 4, oxydiphthalic dianhydride

 PMDA: pyromellitic anhydride

 PA: phthalic anhydride

 DABA: 4, 4,-Gaminobensanilide

t-DACH: trans 1,4-diaminocyclohexane DDE: 4,4'-diaminodiphenyl ether

DDS: 3, 3, diaminodiphenyl sulfone

PDA: p-Phenylenediamine

 SiDA: Bis (3-aminopropyl) tetramethyldisiloxane m-TB-HG: 2, 2'-Dimethenolevenedidine

TFMB: 2, 2'-bis (trifluoromethyl) benzidine

[table 1]

LL0 90 / L00ZdT / 13d zv £ 8t0 difficulty 00Z OAV

Claims

The scope of the claims

 [1] Used in a liquid crystal display device, has optically negative uniaxial anisotropy, the optical axis is substantially perpendicular to the thin film surface, and the birefringence Δη in the thickness direction is 0.01 to 0.3. A resin composition for forming a retardation film, comprising a polyimide precursor obtained by reacting at least one tetracarboxylic dianhydride and at least one diamine, and an organic solvent, A resin composition for forming a retardation film, wherein at least one of the at least one tetracarboxylic dianhydride and the at least one diamine is an alicyclic compound.

 [2] Diamine, an alicyclic compound, has the following general formula (1)

[Chemical 1]

(In the formula, R ¹ represents a monovalent organic group or a hydrogen atom.)

 The composition according to claim 1, which is a trans-1,4-diaminocyclohexane compound represented by the formula:

 [3] Tetracarboxylic dianhydride is represented by the following general formula (2)

 [Chemical 2]

 )

 The composition according to claim 2, which is a 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride compound represented by the formula:

 [4] The composition according to claim 3, wherein the polyimide precursor has at least a structural unit represented by the following general formula (3).

[Chemical 3]

(In the formula, R ² , R ⁴ and R ⁵ each independently represent a monovalent organic group or a hydrogen atom.)

 5. The composition according to claim 1, which is a tetracarboxylic dianhydride strength 1,2,3,4-cyclobutanetetracarboxylic dianhydride which is an alicyclic compound.

6. The composition according to claim 5, wherein the diamine is an aromatic diamine having a rigid molecular structure.

7. The composition according to claim 6, wherein the aromatic diamine having a rigid molecular structure is at least one selected from P-phenediamine, 4,4′-diamineamino-lide.

[8] The following general formula (1)

[Chemical 4]

(In the formula, R ¹ represents a monovalent organic group or a hydrogen atom.)

 A diamine component containing a trans-1,4-diaminocyclohexane compound represented by the formula:

 [Chemical 5]

(In the formula, R ² and R ³ each independently represent a monovalent organic group or a hydrogen atom.)

Contains a polyamic acid compound obtained by reacting a tetracarboxylic dianhydride component including a 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride compound represented by A resin composition for use in a liquid crystal display device to form a retardation thin film having optically negative uniaxial anisotropy and an optical axis being substantially perpendicular to the thin film surface.

 [9] The composition according to claim 8, wherein the polyamic acid compound has at least a structural unit represented by the following general formula (3).

 [Chemical 6]

(Where

R ⁴ and R ⁵ each independently represent a monovalent organic group or a hydrogen atom. )

10. The composition according to claim 9, wherein R ¹ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and R ² , R ⁴ and R ⁵ are hydrogen atoms.

 [11] The polyamic acid compound according to claim 9 or 10, further comprising at least one structural unit selected from the group consisting of structural unit forces represented by the following general formulas (4) to (8): Composition.

 [Chemical 7]

 [Chemical 8]

[Chemical 9]

 [Chemical 10]

(In the formulas (4), (5), (6), (7) and (8),

R ⁴ and R ⁵ each independently represent a monovalent organic group or a hydrogen atom. )

[12] In the formulas (4), (5), (6), (7) and (8), R ¹ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. Yes, R ² ,

The composition according to claim 10, wherein R ⁴ and R ⁵ are hydrogen atoms.

 [13] The total content of structural units represented by the formula (3), (4), (5), (6), (7) or (8) is 50 mol% of all structural units constituting the polyamic acid. The composition according to claim 11 or 12, which is as described above.

[14] A part or all of amine end groups of the polyimide precursor or the polyamic acid are end-capped by an amic acid forming reaction with a dicarboxylic acid anhydride.

14. The resin composition according to any one of 13 above.

15. The composition according to claim 14, wherein the dicarboxylic acid anhydride power is at least one dicarboxylic acid anhydride selected also for maleic anhydride, phthalic anhydride, succinic anhydride, and nadic anhydride power.

 [16] Use of the composition according to any one of claims 1 to 15 for producing a resin composition for forming a retardation film.

 [17] A color filter substrate for a liquid crystal display device in which pixels of each color of red, blue, and green are two-dimensionally arranged on a transparent substrate, and the phase difference according to any one of claims 1 to 15 A color filter substrate for a liquid crystal display device on which a retardation film formed from a resin composition for a thin film is formed.

[18] The retardation film has the following general formula (8) [Chemical 11]

(Where

R ² and R ³ each independently represent a monovalent organic group or a hydrogen atom. )

 The color filter substrate according to claim 17, comprising a polyimide containing 50 mol% or more of a structural unit represented by:

19. The color filter substrate according to claim 18, wherein R ¹ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and R ² and R ³ are hydrogen atoms.

 20. The color filter substrate for a liquid crystal display device according to any one of claims 17 to 19, wherein the retardation film formed from the resin composition for retardation film is formed so as to cover a pixel. .

 [21] A liquid crystal display device using the color filter substrate for a liquid crystal display device according to any one of claims 17 to 20, wherein the display method of the liquid crystal display device is liquid crystal when no voltage is applied. A liquid crystal display device that is a liquid crystal display system in which molecules are aligned in a direction substantially perpendicular to the liquid crystal cell surface, and liquid crystal molecules are aligned in a direction substantially parallel to the liquid crystal cell surface when a voltage is applied.

 [22] A color filter substrate in which the resin composition for retardation film according to any one of claims 1 to 15 is arranged on a transparent substrate in which pixels of each color of red, blue, and green are two-dimensionally arranged. A method for producing a color filter substrate for a liquid crystal display device with a retardation film, which comprises applying to a surface on which the pixels are arranged and heat-treating.