KR20160068764A - Polyimide composition, and alignment film and optical element formed using polyimide composition - Google Patents

Abstract

(일반식 (1) 에 있어서, X 는, 탄소수 5 이상의 4 가의 지방족 탄화수소기를 나타내고, R¹ 은 방향 고리를 갖는 2 가의 유기기를 나타내고, n 은 1 이상의 정수를 나타내고, n 이 2 이상인 경우는, 일반식 (1) 로 나타내는 구조 1 분자 중에 복수 존재하는 R¹ 및 X 는 각각 동일하거나 상이하여도 된다.)A polyimide composition for use in an alignment film for an anisotropic coloring film, wherein the polyimide composition comprises a polyimide and a solvent, and the polyimide is represented by the general formula (1).

(In the general formula (1), X represents a tetravalent aliphatic hydrocarbon group having 5 or more carbon atoms, R ¹ represents a divalent organic group having an aromatic ring, n represents an integer of 1 or more, and when n is 2 or more, R < ^{1 >} and X < ² > present in plural molecules in one molecule of the structure represented by the general formula (1) may be the same or different.)

Description

TECHNICAL FIELD [0001] The present invention relates to a polyimide composition, an alignment layer formed using the polyimide composition, and an optical element,

The present invention relates to a polyimide composition containing a polyimide having a specific structure and used in an alignment film for an anisotropic coloring film. The present invention also relates to an alignment film and an optical element formed using the polyimide composition.

BACKGROUND ART [0002] In recent years, with the spread of liquid crystal displays, various uses of liquid crystal displays are being used. Accordingly, various tasks are proposed and reviewed. In particular, there is a growing demand for optical elements, particularly polarizing elements, particularly durability against humidity, heat and light. Conventional liquid crystal displays use a polarizing film obtained by dyeing and stretching a polyvinyl alcohol (PVA) film or the like with a solution containing a dye and orienting the dye in a stretching process, and therefore the durability against humidity is low. Therefore, it is expected to establish a technique of an anisotropic dye film (polarizing film) using a dye to improve wettability and heat resistance.

As a method of obtaining an anisotropic dye film, there is disclosed a method of obtaining an anisotropic dye film by applying a dichroic dye to the polymer surface (Patent Document 1).

In addition, when an anisotropic dye film is applied, an orientation film is formed on the application substrate to orient the dye. For example, it has been disclosed that an alignment film is obtained by applying and heating a polyamic acid solution (polyimide precursor) to a substrate (Patent Document 2).

An alignment film for a liquid crystal has been conventionally studied as an alignment film, and a liquid crystal alignment film is obtained by applying and heating a polyamic acid solution to a substrate (Patent Document 3).

On the other hand, polyimide has also been studied as an optical film application. For example, in order to obtain a film excellent in heat resistance, transmittance, mechanical properties and heat resistance, a polyamic acid solution is applied and then heated (Patent Documents 4 and 6). It has also been disclosed that a film is obtained by applying a polyimide solution excellent in solubility in an organic solvent, heat resistance, dimensional stability and transparency (Patent Document 5).

In recent years, in order to cope with the development of lighter weight liquid crystal display, improvement of impact resistance, and development of flexibility, the substrate has been studied as plastic. Since the plastic substrates used in these materials have low heat resistance, it is required to lower the temperature of the liquid crystal display manufacturing process.

In addition, in order to increase the brightness of a liquid crystal display, it has been studied to use a coloring agent of a color filter as a dye. In this case, since the heat resistance of the dye is low, it is required to set the temperature of the process after the color filter production to 180 deg. C or lower, which is lower than the conventionally used temperature (Patent Document 7).

Japanese Patent Application Laid-Open No. 2009-217011 Japanese Laid-Open Patent Publication No. 2010-72521 Japanese Patent Application Laid-Open No. 2000-305088 Japanese Patent Application Laid-Open No. 8-104750 Japanese Laid-Open Patent Publication No. 2012-146905 Japanese Patent Application Laid-Open No. 2007-161930 Japanese Laid-Open Patent Publication No. 2011-253054

Patent Document 1 discloses that an anisotropic dye film is produced by applying a dichroic dye to the surface of a polymer. However, the formation of an alignment film has not been studied.

Patent Documents 2 and 3 disclose that a polyimide film is obtained by applying a polyamic acid solution onto a substrate and subjecting the film to a heat treatment at a high temperature of 200 占 폚 or more. Accordingly, an alignment film for an anisotropic coloring film can not be formed on a material having heat resistance of 200 DEG C or lower. For example, there is a problem in that luminance is lowered in a high-luminance color filter using a dye which is being developed recently, when the treatment is performed at a high temperature of 200 캜 or more.

On the other hand, when a polyamic acid solution is applied to a substrate or the like and subjected to heat treatment at 200 占 폚 or lower, the imidization reaction does not proceed sufficiently, and the amic acid moiety remains in the alignment film. The remaining amic acid moiety tends to cause the following problems (1) to (6). Therefore, an alignment film using such a polyamic acid can not be used as an alignment film for an anisotropic coloring film.

(1) Even after the optical element is formed by using the alignment film, the imidization reaction of the alignment film proceeds and water is generated. This water breaks the association of the anisotropic coloring matter, and deterioration of the anisotropic coloring film occurs.

(2) The residual amic acid moiety is hydrolyzed, and the molecular weight of the polyimide is lowered, whereby the physical properties of the alignment film are changed and deterioration of orientation characteristics occurs.

(3) The residual amic acid moiety is hydrolyzed to generate a carboxylic acid end or an amine end rich in reactivity, thereby accelerating the deterioration and coloring of the pigment and the peripheral members in the anisotropic dye film.

(4) Solvent molecules captured at amic acid sites rich in affinity with solvents are difficult to remove even during the drying process, and become outgas volatilized during subsequent processes or storage, deteriorating the devices and peripheral members.

(5) When the composition for an anisotropic coloring matter film is applied, the remaining amic acid moiety absorbs the solvent or the like in the composition for the anisotropic coloring film, and the orientation film swells. Further, by releasing the absorbed water, the association of the anisotropic coloring matter is destroyed, and deterioration of the anisotropic coloring film occurs.

(6) When the ring-clad imidization reaction is carried out after application of the polyamic acid to reduce remaining amic acid moieties, the water accompanying the ring closure causes surface unevenness or microbubbles in the alignment film. The orientation film in which these are formed has poor surface smoothness, which hinders the orientation properties and surface smoothness of the anisotropic dye film.

Patent Document 3 discloses that polyimide is used for the liquid crystal alignment film, but no study has been made as an orientation film for the anisotropic color film. The liquid crystal alignment film aligns liquid crystal molecules of about several tens of angstroms per molecule. On the other hand, the alignment film for the anisotropic coloring film needs to align a column of several hundred angstroms associated with the anisotropic dye. Due to the difference in size of alignment in this way, the characteristics required for each alignment film are different, and the alignment film for liquid crystal can not be used as the alignment film for the anisotropic color film.

Patent Documents 4 to 6 are used for an optical film, and it is difficult to transfer them to an orientation film for an anisotropic coloring film. In Patent Documents 4 and 6, similarly to Patent Documents 2 and 3, in order to obtain a film, it is necessary to apply a polyamic acid solution and then conduct heat treatment at a high temperature of 200 ° C or more. Further, according to a study by the present inventors, polyimides used in Patent Document 5 have a high hydrophobicity and have a problem that the applicability to an anisotropic color film composition is lowered.

Disclosure of the Invention An object of the present invention is to provide a polyimide composition containing polyimide excellent in solubility in a solvent by solving the problems of the prior art. Another object of the present invention is to provide a polyimide composition capable of being subjected to a low-temperature treatment when the polyimide composition is excellent in coatability and an orientation film is formed using the polyimide composition. It is another object of the present invention to provide a polyimide composition having a high degree of internal surface treatment and a high orientation property of the resulting alignment film.

Means for Solving the Problems As a result of intensive investigations in order to achieve the above object, the present inventors have found that polyimide having a specific structure is excellent in solubility in a solvent, and that when a polyimide composition comprising the polyimide and a solvent is used, I found something excellent. By using a polyimide composition containing a polyimide having high solubility, it is not necessary to carry out an imidization reaction at a high temperature after coating. In other words, at the time of forming the alignment film, it is only necessary to remove the solvent of the applied alignment film, and the alignment film can be formed on a material such as a color filter because it can be performed at a temperature lower than 200 ° C.

Further, it has been found that the alignment film obtained from the polyimide composition has excellent inner surface treatment properties such as rubbing and has high orientation properties of the anisotropic dye film.

The present invention has been accomplished based on these findings.

That is, the gist of the present invention is the following [1] to [5].

〔One〕

A polyimide composition for use in an alignment film for an anisotropic coloring film,

The polyimide composition comprises a polyimide and a solvent,

Wherein the polyimide is represented by the general formula (1).

[Chemical Formula 1]

(In the general formula (1), X represents a tetravalent aliphatic hydrocarbon group having 5 or more carbon atoms,

R ¹ represents a divalent organic group having an aromatic ring,

n represents an integer of 1 or more, and when n is 2 or more, a plurality of R ¹ and X in a single molecule of the structure represented by the general formula (1) may be the same or different.

〔2〕

The polyimide composition according to the above [1], wherein the ratio of the number of elements forming the aromatic ring in the number of elements forming the main chain of the polyimide is 5% or more and 75% or less.

[3]

The polyimide composition according to the above [1] or [2], wherein the imidization ratio of the polyimide is 90% or more.

〔4〕

An alignment film for anisotropic color film, which is formed using the polyimide composition according to any one of [1] to [3].

[5]

An optical element having the anisotropic dye film alignment film described in [4] and an anisotropic dye film laminated on the alignment film for the anisotropic dye film.

The polyimide having a specific structure of the present invention has excellent solubility in a solvent, and the polyimide composition containing the polyimide and the solvent has excellent applicability. By using the polyimide composition of the present invention, it is not necessary to conduct the imidization reaction at a high temperature after coating, and only the removal of the solvent of the coating film can be performed at a low temperature, and an alignment film can be formed on a material such as a color filter.

In addition, it is possible to obtain an alignment film excellent in the inner surface treatment property against the treatment such as rubbing and having the high alignment property of the anisotropic coloring film.

The reason for exerting the above effect is not clear, but is presumed to be as follows. The X of the polyimide represented by the general formula (1) contained in the polyimide composition of the present invention is a tetravalent aliphatic hydrocarbon group having 5 or more carbon atoms, whereby the solubility of the polyimide in the solvent can be improved. Since the polyimide in the polyimide composition is hardly precipitated, the applicability of the polyimide composition is improved. Further, since the polyimide composition of the present invention has a high solubility in a solvent even when the imidization rate of the polyimide is high, it is not necessary to conduct the imidization reaction by heating after coating, and a solvent It is possible to form an alignment film.

Since R ^{1 in the} general formula (1) is a divalent organic group having an aromatic ring, the polyimide of the present invention has a rigid structure and a linear property. When the polyimide has linearity, the effect of surface treatment such as rubbing on the alignment film is more easily obtained. By the surface treatment effect of the rubbing or the like, the linearity of the polyimide in the alignment film increases, and the orientation property of the anisotropic dye film formed on the surface can be enhanced.

R ¹ is a bivalent organic group having a ring, and the R ¹ moiety represents an electron donor (donor). On the other hand, since the imide ring structure portion of the polyimide exhibits electron acceptability (acceptor), the polyimide in the polyimide composition can be recycled by the donor-acceptor interaction. Accordingly, the alignment characteristic of the alignment film is improved, and the alignment characteristic of the anisotropic coloring film formed on the surface of the alignment film can be enhanced.

In addition, the polyimide of the present invention has a rigid structure, and since the polyimide can be recycled as described above, the surface treatment property is excellent. Therefore, it is possible to perform a strong surface treatment on the orientation film, and it is possible to further improve the orientation property of the polyimide. In the present invention, the electron donor means a state in which the electron density of the π electron cloud on the aromatic ring is high, and the electron acceptability means a state in which the electron density is low.

The polyimide of the present invention is a combination of X and R ^{1 described} above, and it is possible to improve the recycling of the polyimide in the polyimide composition by the donor-acceptor interaction while maintaining the solubility in the solvent. Therefore, the orientation characteristic of the obtained alignment film is improved, and the orientation characteristic of the anisotropic dye film can be enhanced. Further, since the alignment film of the present invention has an aromatic ring, it has an excellent interaction with an anisotropic dye having an aromatic ring, and thus tends to be able to further enhance the orientation property of the anisotropic dye film. Unlike the liquid crystal molecules, the anisotropic dye takes a relatively large association (column) structure of about a few hundred angstroms associated with the anisotropic dye, and thus it is considered difficult to align the alignment film following the alignment film. Therefore, in order to align anisotropic dyes, alignment films having high alignment properties are required. However, polyimides having a specific structure of the present invention have a high alignment property of the alignment film for the reasons described above, It is appropriate.

Hereinafter, the embodiments of the present invention will be described, but the following examples and methods are examples (representative examples) of the embodiments of the present invention, and the present invention is not limited to these contents Do not.

Herein, "mass%" and "weight%"

1. Polyimide composition

The polyimide composition of the present invention is characterized by containing a polyimide represented by the general formula (1) and a solvent.

(2)

(In the general formula (1), X represents a tetravalent aliphatic hydrocarbon group having 5 or more carbon atoms,

R ¹ represents a divalent organic group having an aromatic ring,

n represents an integer of 1 or more, and when n is 2 or more, a plurality of R ¹ and X in a single molecule of the structure represented by the general formula (1) may be the same or different.

The polyimide composition of the present invention may contain a plurality of polyimides as long as it contains the polyimide represented by the general formula (1). The polyimide of the present invention does not have to be synthesized under the same reaction conditions, and only have the same aromatic element ratio, imidization ratio and solubility. Or may be a mixture prepared by dissolving the above-mentioned materials in different conditions. In the present invention, the aromatic ring element ratio or the imidization ratio described later is an average value of the polyimide constituting the polyimide composition.

The polyimide composition of the present invention may contain components other than polyimide as long as the effect of the present invention is not impaired.

1.1 Solvent

The solvent used in the polyimide composition of the present invention is not particularly limited, and examples thereof include hydrocarbon solvents such as hexane, cyclohexane and heptane; Aromatic solvents such as benzene, toluene, xylene, mesitylene, phenol, cresol and anisole; Halogenated hydrocarbon solvents such as carbon tetrachloride, methylene chloride, chloroform, 1,2-dichloroethane, chlorobenzene, dichlorobenzene and fluorobenzene; Ether solvents such as diethyl ether, tetrahydrofuran, 1,4-dioxane, and methoxybenzene; Ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone and methyl isobutyl ketone; Glycol solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and propylene glycol monomethyl ether acetate; Amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methyl-2-pyrrolidone; Aprotic polar solvents such as dimethylsulfoxide; Heterocyclic solvents such as pyridine, picoline, lutidine, quinoline and isoquinoline; lactone solvents such as? -butyrolactone,? -valerolactone and? -valerolactone; And the like. These solvents may be used singly or in a combination of two or more in an arbitrary ratio and in any combination.

Among them, it is preferable to use a hydrocarbon solvent, an aromatic solvent, a glycol solvent and an amide solvent. Particularly, it is preferable to use toluene, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and anisole. Use of these solvents tends to improve the solubility of the polyimide and to facilitate removal of the solvent at the time of formation of the alignment film.

1.2 Polyimide

The polyimide related to the present invention is not particularly limited as long as it contains a repeating unit containing at least an imide bond and has a skeleton of a specific structure represented by the general formula (1).

(n)

n is an integer of 1 or more and is not particularly limited as long as the effect of the present invention is not impaired, but it is preferable to set n such that the mass average molecular weight of the polyimide represented by formula (1) is in the range described below. These ranges are preferable because the solubility of the polyimide in a solvent and the viscosity of the polyimide composition tends to become a range in which an alignment film can be easily formed.

When n is 2 or more, a plurality of R ¹ and X present in one molecule of the structure represented by the general formula (I) may be the same or different.

(X)

X in the general formula (1) represents a tetravalent aliphatic hydrocarbon group having 5 or more carbon atoms. The aliphatic hydrocarbon group may be cyclic or chain-like, and may be a combination of these.

The carbon number of X is 5 or more, preferably 6 or more. Further preferably 20 or less, more preferably 16 or less, particularly preferably 14 or less. When the number of carbon atoms is within this range, the solubility of the polyimide in a solvent is improved, the polyimide composition is excellent in coatability, and heating after application tends to be carried out at a low temperature.

Among the aliphatic hydrocarbon groups, a group comprising a cyclic aliphatic hydrocarbon group or a combination of cyclic and chain aliphatic hydrocarbon groups improves the solubility of the polyimide in a solvent and the coating ability of the polyimide composition, and the heating after the coating is carried out at a low temperature So that it is preferable.

Examples of the chain type aliphatic hydrocarbon group include an alkylene group which may have a substituent. The chain aliphatic hydrocarbon group may be linear or branched. Examples of the substituent which the alkylene group may have include an alkoxyl group having 1 to 4 carbon atoms, a trifluoromethyl group, and the like.

The cyclic aliphatic hydrocarbon group is a monocyclic ring, a condensed ring, and they are linked to each other by direct or bridging. Specific examples thereof include groups derived from an alicyclic tetracarboxylic acid dianhydride, which will be described later.

Of the cyclic aliphatic hydrocarbon groups, it is preferable that the monocyclic or monocyclic rings are connected to each other directly or by a bridging atom because the solubility of the polyimide in the solvent tends to be improved.

Specific examples of the cyclic aliphatic hydrocarbon group of the monocyclic and polycyclic multicyclic ring include monocyclic rings such as cyclopentane, cyclopentene, cyclohexane, cyclohexene, cycloheptane, etc., condensed polycyclic rings sharing two carbon atoms of the above ring .

Among them, the structure of the formula (2), the formula (3) or the formula (4) is preferable, and the structure of the formula (2) or the formula (3) is particularly preferable. By such a structure, the solubility of the polyimide in a solvent is improved, the coating property of the polyimide composition is excellent, and the post-application heating tends to be carried out at a low temperature.

(3)

The cyclic aliphatic hydrocarbon group in which the monocyclic or condensed polycyclic aromatic group is linked directly or via a bridging atom is preferably a structure represented by the following general formula (5), wherein the solubility of the polyimide in a solvent is improved and the coating property of the polyimide composition And it is preferable since heating after application is likely to be carried out at a low temperature.

[Chemical Formula 4]

In formula (5), X ¹ and X ² each independently represent a divalent cyclic aliphatic hydrocarbon group having 5 or more carbon atoms, R ² represents a direct bond, an alkylene group having 1 to 6 carbon atoms which may have a substituent, ≪ / RTI >

[Chemical Formula 5]

(X ¹ and X ² )

The divalent cyclic aliphatic hydrocarbon group of X ¹ and X ² is not particularly limited as long as the number of carbon atoms is 5 or more, but it is preferably 10 or less, more preferably 8 or less. Further, when the number of carbon atoms is 5 or 6, the solubility of the polyimide in a solvent is improved, the polyimide composition is excellent in coatability, and heating after application tends to be carried out at a low temperature.

X ¹ and X ² may be the same or different and each independently represent an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkylthio group having 1 to 5 carbon atoms, a carboxyl group, a sulfo group, an amino group, a cyano group, Atoms and the like.

(R ² )

R ² is a direct bond, an alkylene group having 1 to 6 carbon atoms which may have a substituent, or a group represented by the following formula:

[Chemical Formula 6]

Among these, a direct bond is preferable because the solubility of the polyimide in a solvent is improved, the polyimide composition is excellent in coatability, and the post-application heating can be carried out at a low temperature.

Examples of the substituent which the alkylene group of R ² may have include an alkoxy group having 1 to 5 carbon atoms, an alkylcarbonyl group having 1 to 5 carbon atoms, a carboxyl group, a sulfo group, a cyano group, a nitro group, a halogen atom, A trifluoromethyl group, and the like.

Among the general formula (5), those represented by the following general formula (6) and the following general formula (7) are preferred because the solubility of the polyimide in a solvent is improved and the coating property of the polyimide composition is excellent, It is preferable that the subsequent heating can be carried out at a low temperature.

(7)

R ³ in the general formula (6) agrees with R ^{2 in the} general formula (5), and the preferable range is also synonymous.

[Chemical Formula 8]

(R ¹ )

R ¹ represents any divalent organic group having an aromatic ring. R ¹ is not particularly limited as long as it is a divalent group having an aromatic ring, and the number of aromatic rings to be provided is not particularly limited. In addition, a group other than the aromatic ring may be contained.

The aromatic ring possessed by the organic group may be a monocyclic ring, a condensed polycyclic ring, and they may be linked to each other directly or via a bridging atom. In addition, the directional ring may be connected to a group other than the directional ring.

Examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a biphenylene ring and a fluorene ring.

These aromatic rings may have a substituent. Examples of the substituent which may be present include an alkyl group having 1 to 5 carbon atoms, a sulfo group, a cyano group, a trifluoromethyl group, a halogen atom and the like.

Examples of the group other than the aromatic ring include an alkylene group having 1 to 4 carbon atoms, an alkenylene group having 1 to 4 carbon atoms, or a group shown below.

[Chemical Formula 9]

The alkylene group having 1 to 4 carbon atoms and the alkenylene group having 1 to 4 carbon atoms, which are exemplified in the groups other than the aromatic ring, may have a substituent. Examples of the substituent which may be present include an alkoxy group having 1 to 5 carbon atoms, an alkylcarbonyl group having 1 to 5 carbon atoms, a carboxyl group, a sulfo group, a cyano group, a nitro group, a halogen atom and an alkylthio group having 1 to 5 carbon atoms .

The connecting position at which the aromatic ring is connected to the direct bond and the group other than the aromatic ring is not particularly limited, but is preferably connected at a position that does not interfere with the rigidity, recurrence and orientation properties of the polyimide molecule.

Specific examples of R ¹ include a divalent group obtained by removing an amino group from a diamine compound which is a raw material of a polyimide represented by the following general formula (1).

Among them, the aromatic ring of R < ¹ > is preferably a ^single ring in view of the solubility of the polyimide in a solvent. The number of aromatic rings of R ¹ is preferably 1 or more, and more preferably 2 or more. The number of aromatic rings is preferably 6 or less, more preferably 4 or less. When the number of aromatic rings is in the above range, the solubility of the polyimide in a solvent is obtained, the rigidity and recycling of the polyimide are improved, and the orientation property and the surface treatment property of the obtained orientation film tend to be improved.

R ¹ is particularly preferably a structure represented by the following formula (8), (9), (10) or (11) By virtue of these structures, the solubility of the polyimide in a solvent is obtained, the rigidity of the polyimide and the recurrence of the polyimide are improved, and the orientation property and the surface treatment property of the resulting oriented film tend to be improved.

[Chemical formula 10]

R ¹³ ~ R ¹⁵ of formula (9) R ^10, formula (10) R ¹¹ ~ R ^12, (11) of the can, each independently, a linking group other than 2-valent aromatic ring, specifically, wherein R ¹ ≪ / RTI > and the like.

Each of the aromatic rings in the formulas (8) to (11) may have an alkyl group having 1 to 5 carbon atoms, a sulfo group, a cyano group, a trifluoromethyl group, a halogen atom or the like as a substituent.

R ¹⁰ to R ¹⁵ are preferably an alkylene group having 1 to 4 carbon atoms or a group represented by the following formula since the rigidity and recurrence of the polyimide are improved and the orientation property and the surface treatment property of the resulting oriented film tend to be improved .

(11)

At least one of R ¹⁰ , R ¹¹ and R ¹² , or at least one of R ¹³ to R ¹⁵ , is -O-, the number of electrons in R ¹ increases, and the amount of poly The orientation of the resulting alignment film tends to be improved, and is particularly preferable.

(Combination of X and R ¹ )

The combination of X and R ¹ described above is not particularly limited, but is preferably a combination in which X is a cyclic aliphatic hydrocarbon group and R ¹ is a structure having a plurality of monocyclic aromatic rings. It is particularly preferable that X includes at least one structure represented by any one of formulas (2) to (7), and R ¹ includes at least one structure represented by formulas (8) to (9). By these combinations, the recrystallization of the polyimide in the polyimide composition due to the donor-acceptor interaction is improved, and the orientation characteristics of the obtained alignment film tend to be improved.

(Other structures)

The polyimide of the present invention is not particularly limited as long as it contains the polyimide represented by the general formula (1), and the polyimide of the present invention may be obtained by combining a plurality of units derived from a tetracarboxylic acid dianhydride and / . The polyimide composition may contain a polyimide other than the polyimide represented by the general formula (1).

The unit derived from the tetracarboxylic acid dianhydride to be copolymerized may contain other than the aliphatic hydrocarbon group having 5 or more carbon atoms as long as the effect of the present invention is not impaired. Specific examples thereof include aromatic rings such as benzene rings and naphthalene rings, groups in which aromatic rings are directly bonded, and groups in which aromatic rings are connected to each other through connecting groups other than aromatic rings. The aromatic ring may have a substituent, and examples thereof include an alkyl group having 1 to 5 carbon atoms, a sulfo group, a cyano group, a trifluoromethyl group, and a halogen atom.

Specific examples of the unit derived from the tetracarboxylic acid dianhydride to be copolymerized include a group derived from a tetracarboxylic acid dianhydride having a directional ring described later as a raw material of polyimide. Among them, a group derived from a tetracarboxylic acid dianhydride having an aromatic ring includes structures represented by the following formulas (12) to (14). Use of these is preferable because rigidity and recycling of the polyimide are improved while maintaining the solubility of the polyimide in a solvent, and orientation properties and surface treatment property of the resulting oriented film tend to be improved.

These aromatic rings may have a substituent. Examples of the substituent which may be present include an alkyl group having 1 to 5 carbon atoms, a sulfo group, a cyano group, a trifluoromethyl group, a halogen atom and the like.

[Chemical Formula 12]

R ¹⁵ represents an alkylene group having 1 to 4 carbon atoms, an alkenylene group having 1 to 4 carbon atoms, or a group represented by the following formula: The connecting position of R < ¹⁵ > is not particularly limited, but is preferably connected at a position that does not interfere with rigidity, recurrence and orientation properties of the polyimide molecule.

[Chemical Formula 13]

In the present invention, among the units derived from the tetracarboxylic acid dianhydride contained in the polyimide, other than the unit derived from the tetracarboxylic acid dianhydride used in the general formula (1) (other tetracarboxylic acid 2 Is preferably 0.1 mol% or more, more preferably 1 mol% or more, preferably 99 mol% or less, more preferably 90 mol% or less. These ranges are preferable because the rigidity and recyclability of the polyimide are improved while maintaining the solubility of the polyimide in a solvent, and the orientation properties and the surface treatment property of the resulting oriented film tend to be improved.

The unit derived from the diamine compound to be copolymerized may not contain an aromatic ring as long as the effect of the present invention is not impaired. For example, a cyclic or chain aliphatic hydrocarbon group, a group connecting an aliphatic hydrocarbon group, and the like. These groups may have a substituent, and examples thereof include an alkyl group having 1 to 5 carbon atoms, a sulfo group, a cyano group, a trifluoromethyl group, and a halogen atom.

Specifically, as a raw material for the polyimide, there can be mentioned a bivalent group obtained by removing an amino group from an aliphatic diamine compound having no aromatic ring, which will be described later.

Among the units derived from the diamine compound contained in the polyimide of the present invention, the ratio of the units other than the units derived from the diamine compounds used in the general formula (1) (units derived from other diamine compounds to be copolymerized) is preferably 0.1 Mol% or more, preferably 50 mol% or less, more preferably 40 mol% or less. These ranges are preferable because the rigidity and recyclability of the polyimide are improved while maintaining the solubility of the polyimide in a solvent, and the orientation properties and the surface treatment property of the resulting oriented film tend to be improved.

(Ratio of the number of elements forming the aromatic ring of the polyimide)

The ratio of the number of elements forming the aromatic ring in the number of elements forming the main chain of the polyimide (hereinafter may be referred to as the aromatic ring element ratio) is preferably 75% or less, more preferably 65% or less , More preferably not more than 60%, particularly preferably not more than 55%, and most preferably not more than 50%. It is preferably at least 5%, more preferably at least 7%, and even more preferably at least 10%. When the aromatic ring element ratio is in the above range, the polyimide tends to be easily dissolved in the solvent, and when the polyimide composition is heated, precipitation or gelation tends to be difficult to occur. Here, the number of elements forming the main chain does not include the number of elements forming a substituent which is a hydrogen atom or a side chain.

The proportion of the aromatic ring element can be adjusted by adjusting the ratio of the tetracarboxylic acid dianhydride and the diamine compound (hereinafter also referred to as " raw material monomer ") used as the polyimide starting material, It may be in the above range. The orientation ring element ratio of the obtained polyimide and the orientation film containing the polyimide can be determined by analyzing the composition of the raw material monomer obtained by solid NMR and IR.

It can also be obtained by analyzing the composition of the raw material monomers obtained by dissolving in alkali, followed by gas chromatography (GC), ¹ H-NMR, ¹³ C-NMR, two-dimensional NMR and mass spectrometry.

The method of setting the proportion of the aromatic ring element of the polyimide within the above range is preferably a method in which a tetracarboxylic acid dianhydride having an aromatic ring, a tetracarboxylic acid dianhydride having no aromatic ring, a diamine compound having an aromatic ring, Diamine compound at a ratio in which the aromatic ring element ratio falls within the range described above.

(Imidization ratio of polyimide)

The imidization ratio of the polyimide is preferably 90% or more, more preferably 95% or more, particularly preferably 98% or more. Further, there is no upper limit, and a higher one is preferable.

When the imidization rate is within a specific range, the remaining amount of amic acid when the alignment film is formed can be suppressed, and the time-dependent change such as hydrolysis tends to be less likely to occur. Further, since the imidization rate is in a specific range, the necessity of imidization reaction (heating) at the time of forming an alignment film is lowered, and an orientation film tends to be obtained by heating at a low temperature. The imidization rate of the present invention can be controlled according to the conditions of imidization in a production method described later.

In the present invention, the imidization ratio indicates the ratio of the imide bond in the main chain of the polyimide. The imidization rate can be determined by a conventionally known method, for example, NMR, IR, titrimetric method and the like. The imidization rate in the present invention is a value obtained by IR.

An example of obtaining the imidization ratio by IR will be described below. The intensity ratio or the area ratio of the CN stretching vibration of the imide with respect to the reference signal is determined on the basis of a signal which does not change before and after the imidation, for example, a directional ring C = C stretching vibration derived from the skeleton of the main chain .

(A) of the C = C stretching vibration of the sample at the time of 100% imidization, the absorbing strength (B) of the CN stretching vibration, the absorbing strength (A ') of the C = The imide ratio of each polyimide composition can be calculated from the following equation (C) by measuring the absorption intensity (B ') of the CN stretching vibration.

Imidization rate = (B '/ A') / (B / A) * 100 (C)

Preparation of 100% imidated sample is made by heating the sample to be measured at a high temperature. The heating temperature is usually 200 ° C or higher, preferably 250 ° C or higher, and more preferably 300 ° C or higher. The drying temperature of the solvent can be determined according to the boiling point of the solvent used, but is usually 20 ° C or higher, preferably 40 ° C or higher, more preferably 200 ° C or lower, and more preferably lower than the imidization reaction temperature. Since the drying temperature is not too low, the solvent is sufficiently dried and there is a tendency that unwanted signals are not observed during IR measurement. In addition, since the drying temperature is not excessively high, the imidization rate does not change during drying, and an accurate imidization rate can be obtained.

(Solubility of polyimide)

In the present invention, the term "soluble in a solvent" means that the polyimide is completely dissolved when the polyimide is dissolved at room temperature (25 ° C) in a solvent constituting the composition. The concentration to be completely dissolved is usually 0.5% by mass or more, preferably 1% by mass or more, more preferably 10% by mass or more, and further preferably 20% by mass or more.

In the present invention, polyimide soluble in a solvent can be obtained by setting the aromatic ring element ratio and the imidization ratio of the main chain within the above range.

The concentration of the composition can be determined by appropriately using a conventionally known method. For example, the solvent of the composition can be determined from the mass ratio before and after drying by drying using a method such as drying under reduced pressure.

When the concentration of the composition is low, the composition can be concentrated and the solubility can be determined using a method such as distillation under reduced pressure of the solvent. When the concentration of the composition is high, the measurement concentration may be 1% by mass by diluting the composition with a solvent. When the solvent of the composition is unknown, for example, amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methyl-2-pyrrolidone; Aprotic solvents such as dimethylsulfoxide; Glycol solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and propylene glycol monomethyl ether acetate; Aromatic solvents such as benzene, toluene, xylene, mesitylene, phenol, cresol and anisole; Hydrocarbon solvents such as hexane, cyclohexane, and heptane; And the like.

(The ratio of the number of elements forming the aliphatic structure of the polyimide)

The ratio of the number of elements forming an aliphatic structure (hereinafter sometimes referred to as an aliphatic element ratio) in the number of elements forming the main chain of the polyimide is preferably 5% or more of the number of elements forming the main chain of the polyimide , More preferably 7% or more, particularly preferably 10% or more. It is preferably 60% or less, more preferably 50% or less, still more preferably 40% or less, particularly preferably 35% or less. By having an aliphatic structure in the main chain in an appropriate range, there is a tendency to stably obtain a polyimide composition containing a polyimide having high solubility. Here, the number of elements forming the main chain does not include the number of elements forming a substituent which is a hydrogen atom or a side chain. As the structure forming the main chain of the polyimide, in order to have an aliphatic structure, a tetracarboxylic acid dianhydride having an aliphatic structure and a diamine compound may be used in a suitable ratio. Here, the aliphatic structure includes both alicyclic and chained structures.

(Molecular weight of polyimide)

The weight average molecular weight (Mw) of the polyimide is not particularly limited, and in terms of polystyrene usually 1.0 × 10 ³ or more, preferably 5.0 × 10 ^3, more preferably at least 1.0 × 10 ^4, usually 1.0 × 10 ⁶ Or less, preferably 8.0 x 10 < ⁵ > or less, more preferably 5.0 x 10 < ⁵ > These ranges are preferable because the solubility of the polyimide in a solvent and the viscosity of the polyimide composition tends to become a range in which an alignment film can be easily formed. The weight average molecular weight in terms of polystyrene can be determined by gel permeation chromatography (GPC).

The number-average molecular weight (Mn) of the polyimide is not particularly limited, in terms of polystyrene usually 5.0 × 10 ² or more, preferably 2.5 × 10 ³ or more, more preferably 5.0 × 10 ³ or more, and usually 5.0 × 10 ⁴ Or less, preferably 4.0 x 10 ⁴ or less, and more preferably 2.5 x 10 ⁴ or less. Solution viscosity, solution viscosity, melt viscosity and the like are within a range that can be easily handled by ordinary manufacturing equipment. The number average molecular weight of the polyimide can be measured by the same method as the weight average molecular weight.

The molecular weight distribution (PDI, (weight average molecular weight / number average molecular weight (Mw / Mn)) of the polyimide is usually 1 or more, preferably 1.1 or more, more preferably 1.2 or more, 9 or less, more preferably 8 or less. From the viewpoint of obtaining a composition having high uniformity, it is preferable that the molecular weight distribution falls within this range. The molecular weight distribution of the polyimide can be determined from the values of the weight average molecular weight and the number average molecular weight.

1.3 Raw materials of polyimide

The polyimide relating to the present invention is obtained by reacting a tetracarboxylic acid dianhydride and a diamine compound in an organic solvent.

(Tetracarboxylic acid dianhydride)

Examples of the tetracarboxylic acid dianhydride which is a raw material of the polyimide represented by the general formula (1) of the present invention include aliphatic tetracarboxylic dianhydrides having no aromatic ring. Examples of the aliphatic tetracarboxylic acid dianhydride include alicyclic tetracarboxylic acid dianhydrides and chain-like aliphatic tetracarboxylic dianhydrides.

Specific examples of the alicyclic tetracarboxylic acid dianhydride include 3,3 ', 4,4'-biscyclopentanetetracarboxylic acid dianhydride, 3,3', 4,4'-biscyclohexanetetracarboxylic acid 1,2,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, tricyclo [6.4.0.0 2,7] dodecane- 1,8: 2,7-tetracarboxylic acid dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, 1,1'-biscyclo Hexane-3,3 ', 4,4'-tetracarboxylic acid dianhydride, 1,1'-oxybiscyclohexane-3,3', 4,4'-tetracarboxylic acid dianhydride, 1,1 ' -Sulfonylbiscyclohexane-3,3 ', 4,4'-tetracarboxylic acid dianhydride, 1,1'-biscyclohexylketone-3,3', 4,4'-tetracarboxylic acid dianhydride , 1,1'-biscyclohexylmethyl-3,3 ', 4,4'-tetracarboxylic acid dianhydride, 1,1' - (1-methylethylidene) biscyclohexyl-3,3 ' 4,4'-tetracarboxylic acid dianhydride and the like. Can.

Of these, alicyclic tetracarboxylic acid dianhydrides are preferable. Among the alicyclic tetracarboxylic acid dianhydrides, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 3,3 ', 4,4'-biscyclohexanetetracarboxylic dianhydride, 1,2 , 4,5-cyclohexanetetracarboxylic acid dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, 1,1'-bicyclohexane -3,3 ', 4,4'-tetracarboxylic acid dianhydride and the like are improved in the solubility of the polyimide in a solvent, the coating property of the polyimide composition is excellent, and heating after coating can be carried out at a low temperature Which is particularly preferable.

These compounds may be used singly or in a combination of two or more in any ratio and in any combination.

(Diamine compound)

Examples of the diamine compound as a raw material of the polyimide represented by the general formula (1) of the present invention include diamine compounds containing an aromatic ring. Examples of the diamine compound having an aromatic ring include a diamine compound having one aromatic ring contained in the molecule, a diamine compound having two or more independent aromatic rings, and a diamine compound having a condensed aromatic ring.

Specific examples include diamine compounds having one aromatic ring contained in the molecule such as 1,4-phenylenediamine, 1,2-phenylenediamine, and 1,3-phenylenediamine; 4,4'-diaminodiphenyl ether, 1,4-bis (4-biphenyl-2,5-diylbisoxy) bisaniline, Bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 2,2- Phenyl) sulfone, bis (4- (3-aminophenoxy) phenyl) sulfone, 1,3-bis (4-aminophenoxy) neopentane, 4,4'-diamino-3,3'- , 4,4'-diamino-2,2'-dimethylbiphenyl, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4'- diamino-3,3'-dihydroxy (4-amino-3-carboxyphenyl) methane, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfide, N- -Aminobenzylamine, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, bis (3-aminophenyl) sulfone, norbornanediamine, 4,4'- 2- (trifluoromethyl) diphenyl ether, 5-trifluoromethyl-1,3-benzenediamine, 2,2- Bis (4-aminophenoxy) phenyl) hexafluoropropane, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 2,2- Phenyl) hexafluoropropane, 2-trifluoromethyl-p-phenylenediamine, 2,2-bis (3-amino-4-methylphenyl) hexa A diamine compound having two or more independent aromatic rings such as fluoropropane and the like; 4,4'- (9-fluorenylidene) dianiline, 2,7-diaminofluorene, 1,5-diaminonaphthalene, 3,7-diamino-2,8-dimethyldibenzothiophene , 5-dioxide, and the like; And the like.

Among the diamine compounds having an aromatic ring, it is preferable to use a compound having two or more independent aromatic rings. Particularly preferred among them are 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 4,4'-diaminodiphenyl ether, 3,4'- diaminodiphenyl ether, Diamino-2,2'-dimethylbiphenyl and bis (4- (4-aminophenoxy) phenyl) sulfone are particularly preferred because they can maintain solubility and obtain polyimide excellent in dimensional stability.

These compounds may be used singly or in a combination of two or more in any ratio and in any combination.

In addition to the above tetracarboxylic acid dianhydrides and diamine compounds, tetracarboxylic acid dianhydride having an aromatic ring and / or an aliphatic diamine compound having no aromatic ring may be copolymerized within a range that does not impair the effect of the present invention do.

(Tetracarboxylic acid dianhydride having an aromatic ring)

Examples of the tetracarboxylic acid dianhydride having an aromatic ring include tetracarboxylic acid dianhydride having one aromatic ring contained in the molecule, tetracarboxylic dianhydride having two or more independent aromatic rings, and tetraarboxylic acid dianhydride having a condensed aromatic ring. Carboxylic acid dianhydride, and the like.

Specifically, tetracarboxylic acid dianhydride having one aromatic ring contained in the molecule such as pyromellitic dianhydride and 1,2,3,4-benzenetetracarboxylic dianhydride; Bis (2,3-dicarboxyphenyl) methane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2- Bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 3,3 ' Benzophenone tetracarboxylic acid dianhydride, 4,4'-benzophenonetetracarboxylic dianhydride, 2,2 ', 3,3'-benzophenonetetracarboxylic dianhydride, 4,4'-oxydiphthalic dianhydride, Biphenyltetracarboxylic acid dianhydride, 2,2-bis (3-phenylene dioxy) diphthalic acid dianhydride, 2,2 ' , 4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) 3,3-Hexafluoropropane 2 Anhydrous Water, 2,2'-bis (trifluoromethyl) -4,4 ', 5,5'-biphenyltetracarboxylic acid dianhydride, 4,4' - (hexafluorotrimethylene) -diphthalic acid dianhydride Tetracarboxylic dianhydride having two or more independent aromatic rings such as 4,4 '- (octafluorotetramethylene) -diphthalic acid dianhydride and 4,4'-oxydiphthalic anhydride; 1,2,5,6-naphthalene dicarboxylic acid dianhydride, 1,4,5,8-naphthalene dicarboxylic acid dianhydride, 2,3,6,7-naphthalene dicarboxylic acid dianhydride, Condensation of 4,9,10-perylene tetracarboxylic acid dianhydride, 2,3,6,7-anthracene tetracarboxylic acid dianhydride, 1,2,7,8-phenanthrene tetracarboxylic acid dianhydride, etc. Tetracarboxylic dianhydride having an aromatic ring; And the like.

Among them, it is preferable to use a tetracarboxylic acid dianhydride having one aromatic ring contained in the molecule and a tetracarboxylic dianhydride having two or more independent aromatic rings. Among these, pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic acid dianhydride, 4,4'-oxydiphthalic anhydride, 3,3', 4,4'- Phenyltetracarboxylic acid dianhydride is preferable because rigidity and recycling of the polyimide are improved while maintaining the solubility of the polyimide in a solvent and orientation properties and surface treatment property of the resulting oriented film tend to be improved.

(An aliphatic diamine compound having no aromatic ring)

Examples of the aliphatic diamine compound include an alicyclic diamine compound and a chained aliphatic diamine compound.

Specific examples include 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1,4-diaminocyclohexane, 4,4'-methylenebis (cyclohexylamine) Alicyclic diamine compounds such as 4,4'-methylenebis (2-methylcyclohexylamine); (1,2-ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-hexamethylenediamine, Chain aliphatic series such as 10-diaminodecane, 1,2-diamino-2-methylpropane, 2,3-diamino-2,3-butanediamine, 2- Diamine compounds; And the like.

Of these, alicyclic diamine compounds are preferred, and 1,4-diaminocyclohexane and 1,3-bis (aminomethyl) are preferred among them, while solubility of the polyimide in a solvent is maintained, The synthesis is improved and orientation properties and surface treatment property of the alignment film to be obtained tend to be improved.

1.4 Manufacturing method of polyimide

There is no particular limitation on the production method of the polyimide relating to the present invention. For example, there can be used a method of producing a polyamic acid which is a precursor, a method of obtaining a polyimide (two-step method), a method of directly producing a polyimide from a tetracarboxylic acid dianhydride and a diamine compound The method of manufacturing (once the method) is used.

(Two-stage method)

(Synthesis of polyamic acid)

The reaction for obtaining the polyamic acid from the tetracarboxylic acid dianhydride and the diamine compound can be carried out under conventionally known conditions. The order of addition of the tetracarboxylic acid dianhydride and the diamine compound and the addition method thereof are not particularly limited. For example, a polyamic acid composition is obtained by sequentially adding a tetracarboxylic acid dianhydride and a diamine compound to a solvent and stirring at an appropriate temperature.

The amount of the diamine compound is generally 0.7 mol or more, preferably 0.8 mol or more, and usually 1.3 mol or less, and preferably 1.2 mol or less, based on the tetracarboxylic acid dianhydride. When the diamine compound is used in such a range, the yield of the obtained polyamic acid tends to be improved.

The concentration of the tetracarboxylic acid dianhydride and the diamine compound in the solvent can be appropriately set in accordance with the reaction conditions and the viscosity of the polyamic acid. For example, the total mass of the tetracarboxylic acid dianhydride and the diamine compound is not particularly limited, but is usually 1% by mass or more, preferably 5% by mass or more, and usually 70% by mass or less Is not more than 30% by mass. By setting the reaction substrate in this range, a polyamic acid can be obtained in a good yield at a low cost.

The reaction temperature is not particularly limited as long as the reaction proceeds, but is usually 0 ° C or higher, preferably 20 ° C or higher, and usually 120 ° C or lower, preferably 100 ° C or lower. The reaction time is usually 1 hour or more, preferably 2 hours or more, and usually 100 hours or less, preferably 24 hours or less. By carrying out the reaction under such conditions, the polyamic acid can be obtained at a low cost in good yield.

The pressure during the reaction may be atmospheric pressure, pressurized or reduced pressure. The atmosphere may be air or an inert atmosphere.

The solvent used in this reaction is not particularly restricted but includes, for example, hydrocarbon solvents such as hexane, cyclohexane, and heptane; Aromatic solvents such as benzene, toluene, xylene, mesitylene, phenol, cresol and anisole; Halogenated hydrocarbon solvents such as carbon tetrachloride, methylene chloride, chloroform, 1,2-dichloroethane, chlorobenzene, dichlorobenzene and fluorobenzene; Ether solvents such as diethyl ether, tetrahydrofuran, 1,4-dioxane, and methoxybenzene; Ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone and methyl isobutyl ketone; Glycol solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and propylene glycol monomethyl ether acetate; Amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methyl-2-pyrrolidone; Aprotic polar solvents such as dimethylsulfoxide; Heterocyclic solvents such as pyridine, picoline, lutidine, quinoline and isoquinoline; lactone solvents such as? -butyrolactone,? -valerolactone and? -valerolactone; And the like. These solvents may be used singly or in a combination of two or more in an arbitrary ratio and in any combination.

The polyamic acid solution thus obtained may be used as it is, or it may be precipitated in a solid phase by adding it to a poor solvent and then redissolved in another solvent to obtain a polyimide composition.

The poor solvent at this time is not particularly limited and may be appropriately selected depending on the type of the polyimide resin, and examples thereof include ether solvents such as diethyl ether and diisopropyl ether; Ketone solvents such as acetone, methyl ethyl ketone, isobutyl ketone and methyl isobutyl ketone; Alcohol solvents such as methanol, ethanol and isopropyl alcohol; And the like. Among them, an alcohol-based solvent such as isopropyl alcohol is preferable because precipitates are efficiently obtained, the boiling point is lowered, and drying is facilitated.

The solvent for dissolving the polyamic acid is not particularly limited, and examples thereof include amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methyl-2-pyrrolidone; Aprotic solvents such as dimethylsulfoxide; Aromatic solvents such as benzene, toluene, xylene, mesitylene, phenol, cresol and anisole; Glycol solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and propylene glycol monomethyl ether acetate; . Of these, an amide-based solvent, an aromatic-based solvent and a glycol-based solvent are preferable. Particularly preferred are N, N-dimethylformamide, N, N-dimethylacetamide or N-methyl-2-pyrrolidone, anisole, ethylene glycol dimethyl ether and ethylene glycol monomethyl ether. These solvents may be used singly or as a mixture of two or more solvents.

(Preparation of polyimide composition from polyamic acid)

By subjecting the polyamic acid to dehydration cyclization in the presence of a solvent, a polyimide composition can be obtained. The imidization can be carried out by any method known in the art, and examples thereof include heat imidization for thermal cyclization and chemical imidization for chemical cyclization. These imidization reactions may be used alone or in combination.

(Heat imidization)

The specific imidization rate of the polyimide of the present invention can be controlled by adjusting the heating temperature, the heating time, the concentration of the polyamic acid in the solvent, and the type of imidization accelerator, the amount of addition, .

The solvent for imidizing the polyamic acid may be the same as the solvent used in the reaction for obtaining the polyamic acid. The solvent for the production of the polyamic acid and the solvent for the production of the polyimide composition may be the same or different.

In this case, the water generated by the imidization reaction inhibits the ring-closing reaction, so that the water may be discharged out of the system. The concentration of the polyamic acid in the imidation reaction is not particularly limited, but is usually 1% by mass or more, preferably 5% by mass or more, and usually 70% by mass or less, preferably 40% by mass or less. In this range, a polyimide having an imidization rate controlled can be obtained. In addition, polyimide can be produced with a solution viscosity that is high in production efficiency and easy to produce.

The imidization reaction temperature is not particularly limited as long as it does not deviate from the present invention. But is usually 50 ° C or higher, preferably 80 ° C or higher, more preferably 100 ° C or higher, and usually 300 ° C or lower, preferably 250 ° C or lower, more preferably 220 ° C or lower, and particularly preferably 200 ° C or lower. By carrying out the reaction in this range, it is possible to obtain a polyimide in which the imidization reaction proceeds efficiently and the imidization rate is controlled. Further, side reactions other than the imidization reaction are suppressed, which is preferable.

The pressure during the reaction may be atmospheric pressure, pressurized, or reduced pressure. The atmosphere may be air or an inert atmosphere.

As an imidization accelerator that promotes imidization, a compound having a nucleophilic property and a function of enhancing the electromotive force may be added. Specific examples of the amine include trimethylamine, triethylamine, tripropylamine, tributylamine, triethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, triethylenediamine, Tertiary amine compounds such as pyrrolidine, N-ethylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, imidazole, pyridine, quinoline and isoquinoline; Carboxylic acid compounds such as 4-hydroxyphenylacetic acid, 3-hydroxybenzoic acid, N-acetylglycine and N-benzoylglycine; Polyhydric phenol compounds such as 3,5-dihydroxyacetophenone, methyl 3,5-dihydroxybenzoate, pyrogallol, methyl gallate, ethyl gallate and naphthalene-1,6-diol; Pyridines such as 2-hydroxypyridine, 3-hydroxypyridine, 4-hydroxypyridine, 4-pyridine methanol, N, N-dimethylaminopyridine, nicotinaldehyde, isonicotinaldehyde, picoline aldehyde, picoline aldehyde oxime, , Isonicotine aldehyde oxime, ethyl picolinate, ethyl nicotinate, ethyl isonitrate, nicotinamide, isonicotinamide, 2-hydroxynicotinic acid, 2,2'-dipyridyl, 4,4'-dipyridyl, 3 Heterocyclic compounds such as methylpyridazine, quinoline, isoquinoline, phenanthroline, 1,10-phenanthroline, imidazole, benzimidazole and 1,2,4-triazole; And the like.

Of these, tertiary amine compounds, carboxylic acid compounds and heterocyclic compounds are preferable, and triethylamine, imidazole and pyridine are more preferable because they tend to control the imidization rate.

These compounds may be used singly or in a combination of two or more in any ratio and in any combination.

The amount of the imidization accelerator to be used is preferably 0.01 mol% or more, more preferably 0.1 mol% or more, and particularly preferably 1 mol% or more, with respect to the carboxyl group or ester group of the amic acid skeleton. Further, it is preferably 50 mol% or less, more preferably 10 mol% or less. When the amount of the catalyst to be used is in this range, the imidization reaction proceeds efficiently, and the polyimide having an imidization rate controlled can be obtained. In addition, the reaction can be carried out with good yield at a low cost.

The timing at which the imidization promoter is added may be appropriately adjusted in order to achieve a desired imidization rate, and may be either before the start of heating or during heating. It may also be added in multiple circuits.

(Chemical imidization)

The polyimide composition can be obtained by chemically imidizing polyamic acid with a dehydrating condensing agent in the presence of a solvent. The specific imidization rate of the polyimide of the present invention is obtained by adjusting the heating temperature, the heating time, the concentration of the polyamic acid in the solvent, the kind of the dehydrating condensing agent, the amount of the dehydrating condensing agent added, .

As the solvent to be used for imidizing the polyamic acid, the same solvents as those exemplified for the synthesis of the polyamic acid in the above-mentioned two-step method can be mentioned.

Examples of the dehydrating condensation agent include N, N-2-substituted carbodiimides such as N, N-dicyclohexylcarbodiimide and N, N-diphenylcarbodiimide; Acid anhydrides such as acetic anhydride and trifluoroacetic anhydride; Chlorides such as thionyl chloride and tosyl chloride; Examples of the solvent include acetyl chloride, acetyl bromide, propionyl iodide, acetyl fluoride, propionyl chloride, propionyl bromide, propionyl iodide, propionyl fluoride, isobutyryl chloride, isobutyryl bromide, Butyryl chloride, n-butyryl bromide, n-butyryl iodide, n-butyryl fluoride, mono-chloroacetyl chloride, di-chloroacetyl chloride, Mono-bromoacetyl chloride, mono-bromoacetyl chloride, mono-iodoacetyl chloride, di-iodoacetyl chloride, tri-iodoacetyl chloride, mono-fluoroacetyl chloride, mono-bromoacetyl chloride, Chloride, di-fluoroacetyl chloride, tri-fluoroacetyl chloride Halogenated compounds, such as fluoride, anhydrous chloroacetic acid, phenyl phosphonate nikdi chloride, thionyl bromide, thionyl iodide, thionyl fluoride; Phosphorus compounds such as phosphorus trichloride, triphenyl phosphite, and diethylphosphoric acid cyanide; And the like.

Of these, acid anhydrides or halogenated compounds are preferable, and acid anhydrides are particularly preferable. By using these, there is a tendency to obtain a polyimide in which the imidization reaction proceeds efficiently and the imidization rate is controlled.

These compounds may be used singly or in a combination of two or more in any ratio and in any combination.

The amount of these dehydrating condensing agents to be used is usually 0.1 mol or more, preferably 0.2 mol or more, and usually 1.0 mol or less, preferably 0.9 mol or less, based on 1 mol of the amic acid skeleton. By setting the dehydrating condensing agent in this range, the imidization rate can be controlled. These may be used alone, or two or more of them may be used in combination.

The concentration of the polyamic acid in the imidation reaction is not particularly limited, but is usually 1% by mass or more, preferably 5% by mass or more, and usually 70% by mass or less, preferably 40% by mass or less. When the concentration is in this range, there is a tendency that the imidization rate can be controlled, the production efficiency is high, and the solution viscosity can be easily produced.

Although the imidization reaction temperature is not particularly limited, the imidization reaction temperature is not particularly limited as long as it does not deviate from the present invention, but is usually 0 ° C or higher, preferably 10 ° C or higher, more preferably 20 ° C or higher , Usually 150 ° C or lower, preferably 130 ° C or lower, more preferably 100 ° C or lower. In this range, it is preferable because imidization reaction proceeds efficiently and polyimide whose imidization rate is controlled can be obtained. Further, side reactions other than the imidization reaction are suppressed, which is preferable.

The pressure during the reaction may be atmospheric pressure, pressurized, or reduced pressure. The atmosphere may be air or an inert atmosphere.

As the catalyst for promoting the imidization, the above-mentioned tertiary amines and the like may be added in the same manner as the heat imidization.

(Once the law)

From the tetracarboxylic acid dianhydride and the diamine compound, a direct polyimide composition can be obtained by a conventionally known method. In this method, the imidization is carried out from the synthesis of the polyamic acid in the two-step method to the imidization without stopping the reaction or isolating the intermediate (polyamic acid).

As in the case of obtaining the polyimide composition from the polyamic acid, the same reaction conditions as the heat imidization and the chemical imidization can be used.

Although the method is not particularly limited, it will be described in detail below. The specific imide conversion rate of the polyimide of the present invention can be obtained by adjusting the heating temperature, the heating time, the concentration of the tetracarboxylic acid dianhydride and the diamine compound, the kind of the additives, the amount of addition, and the timing of addition.

The order of addition of the tetracarboxylic acid dianhydride and the diamine compound and the method of adding the tetracarboxylic acid dianhydride and the diamine compound are not particularly limited. For example, a tetracarboxylic acid dianhydride and a diamine compound are successively added to a solvent and stirred at a temperature at which the reaction to the imidization proceeds, thereby obtaining a polyimide composition.

The amount of the diamine compound is usually 0.7 mol or more, preferably 0.8 mol or more, and usually 1.3 mol or less, preferably 1.2 mol or less, per 1 mol of the tetracarboxylic acid dianhydride. By setting the amount of the diamine compound within this range, a polyimide having an imidization ratio controlled can be obtained, and the yield of the obtained polyimide composition tends to be improved.

The concentration of the tetracarboxylic acid dianhydride and the diamine compound in the solvent can be suitably set for each condition and the viscosity during polymerization. The total mass of the tetracarboxylic acid dianhydride and the diamine compound is not particularly limited, Is usually not less than 1% by mass, preferably not less than 5% by mass, and usually not more than 70% by mass, preferably not more than 40% by mass. If the concentration in the solvent is too low, elongation of the molecular weight becomes difficult to occur. If the concentration is too high, the viscosity becomes too high and stirring becomes difficult. In the above range, polyimide having an imidization ratio controlled can be obtained.

As the solvent to be used in this reaction, the same solvents as mentioned above can be used.

1.5 Method for producing polyimide composition

The obtained polyimide may be used as a polyimide composition as it is or may be added to a poor solvent to precipitate a polyimide in a solid phase and then redissolved in another solvent to be used as a polyimide composition.

The poor solvent at this time is not particularly limited and may be appropriately selected depending on the kind of the polyimide. Examples thereof include ether solvents such as diethyl ether and diisopropyl ether; Ketone solvents such as acetone, methyl ethyl ketone, isobutyl ketone and methyl isobutyl ketone; And alcoholic solvents such as methanol, ethanol and isopropyl alcohol. Among them, an alcohol-based solvent such as isopropyl alcohol is preferable because precipitates are efficiently obtained and the boiling point is low and drying is easy. These solvents may be used singly or in a combination of two or more in an arbitrary ratio and in any combination.

As the solvent for re-dissolving the polyimide, a solvent of the above-mentioned polyimide composition may be mentioned.

In the polyimide composition of the present invention, an imidizing agent may be added to the polyimide composition in order to further increase the rate of diffusion at the time of forming the alignment film.

The imidization agent is not particularly limited as long as it promotes imidization, and the imidization promoter can be used. Preferably, the compound is a carboxylic acid compound or a heterocyclic compound, more preferably a heterocyclic compound, more preferably 2-hydroxypyridine, 3-hydroxypyridine, 4-hydroxypyridine, N, Aminopyridine, nicotinamide, isonicotinamide, imidazole, benzimidazole, 1,2,4-triazole.

These compounds may be used singly or in a combination of two or more in any ratio and in any combination. The addition of the compound may be added at the time of preparing the polyimide composition, or may be added immediately before coating.

To the polyimide composition of the present invention, a coupling agent such as a silane coupling agent or a titanium coupling agent may be added in order to control the adhesiveness with a hydrophobic body. These compounds may be used singly or in a combination of two or more in any ratio and in any combination. At this time, the amount to be used is preferably 0.1% by mass or more and 3% by mass or less with respect to the polyimide.

Examples of the silane coupling agent include, for example,? -Aminopropyltriethoxysilane,? -Aminopropyltrimethoxysilane,? -Aminopropyltripropoxysilane,? -Aminopropyltributoxysilane,? -Aminoethyltri Aminoethyltrimethoxysilane,? -Aminoethyltrimethoxysilane,? -Aminoethyltrimethoxysilane,? -Aminoethyltrimethoxysilane,? -Aminoethyltrimethoxysilane,? -Aminobutyltrimethoxysilane,? -Aminobutyltrimethoxysilane,? -Aminobutyltripropoxysilane,? -Aminobutyltributoxysilane, and the like.

Examples of the titanium coupling agent include γ-aminopropyltriethoxytitanium, γ-aminopropyltrimethoxytitanium, γ-aminopropyltripropoxytitanium, γ-aminopropyltributoxytitanium, γ-aminoethyltri Aminoethyltripropoxytitanium,? -Aminobutyltriethoxytitanium,? -Aminobutyltrimethoxytitanium,? -Aminobutyltrimethoxytitanium,? -Aminobutyltrimethoxytitanium,? -Aminobutyltrimethoxytitanium,? -Aminobutyltrimethoxytitanium, -Aminobutyltripropoxytitanium,? -Aminobutyltributoxytitanium, and the like.

In addition, if necessary, various additives may be blended. For example, an inorganic filler such as other powder, granular, plate, or fibrous filler or an organic filler may be blended to the extent that the effect of the present invention is not impaired.

These fillers may be processed into flat plates such as nonwoven fabric, or a plurality of these fillers may be mixed and used. In addition, various additives commonly used in the resin composition such as a lubricant, a coloring agent, a stabilizer, an antioxidant, an ultraviolet absorber, an antistatic agent, a flame retardant, a plasticizer, a mold release agent and the like may be added. These various fillers and additive components may be added at any stage of any step of producing polyimide.

According to the present invention, there is provided an optical element comprising an alignment film formed from the polyimide composition, the alignment film, and an anisotropic dye film formed from the dye. Hereinafter, these inventions will be described in more detail.

1.6 Method of forming alignment film and alignment film

The alignment film of the present invention can be formed by applying the polyimide composition of the present invention to a donor.

The coating method is not particularly limited as long as it is a method capable of forming a uniform thickness layer, and examples thereof include die coating, spin coating, screen printing, flexographic printing, spraying, casting using an applicator; A method of using a coater; By injection; Dipping method; Calendar method; Flexible method; And the like.

Examples of the material to be coated include glass such as float glass and soda glass; Plastics such as polyethylene terephthalate, polycarbonate and polyolefin; And the like can be used. When the polyimide composition of the present invention is applied, the functional silane-containing compound and the functional titanium-containing compound may be previously coated on the surface of the substrate to be coated. Ultraviolet treatment, plasma treatment, and the like may also be performed.

The method of volatilizing the solvent of the polyimide composition is also not particularly limited. Usually, the solvent is volatilized by heating the coated body coated with the polyimide composition. The heating method is not particularly limited, and examples thereof include hot air heating, vacuum heating, infrared heating, microwave heating, heating by contact using a hot plate or hot roll, and the like.

The heating temperature in the case of drying the solvent of the applied polyimide composition is usually 20 占 폚 or higher, preferably 40 占 폚 or higher, more preferably 50 占 폚 or higher, although a suitable temperature may be used depending on the type of the solvent. It is preferably at most 200 ° C, more preferably at most 180 ° C, even more preferably at most 150 ° C. When the solvent removal temperature is 20 占 폚 or higher, the solvent is preferably sufficiently volatilized. When the solvent removal temperature is 200 DEG C or lower, performance deterioration of each material when an alignment film is formed on a material having low heat resistance, for example, a polyester resin or a polyolefin resin can be suppressed.

In order to further increase the imidization rate of the alignment film after application, it may be further heated. The temperature for increasing the imidization rate is preferably 60 占 폚 or higher, and more preferably 80 占 폚 or higher. It is preferably at most 200 ° C, more preferably at most 180 ° C, even more preferably at most 150 ° C. When the heating temperature is 60 DEG C or higher, the imidization proceeds efficiently and the amount of amic acid remaining as a cause of hydrolysis and the like is reduced, which is preferable. When the heating temperature is 200 ° C or lower, there is a tendency that the performance deterioration of each material when an alignment film is formed on a material having low heat resistance, for example, a polyester resin or a polyolefin resin, tends to be suppressed.

The temperature for raising the solvent removal temperature and the imidization rate may be carried out at different temperatures or at the same temperature, respectively. When the solvent removal and the heating for increasing the imidization rate are carried out, the respective heating methods may be different or may be the same.

The thickness of the obtained alignment film can be controlled by adjusting the application amount of the polyimide composition. The thickness of the alignment film is usually 1 nm or more, preferably 10 nm or more, and usually 10 占 퐉 or less, preferably 5 占 퐉 or less, more preferably 2 占 퐉 or less, particularly preferably 1 占 퐉 or less. When the thickness is 1 nm or more, the uniformity of the film thickness and the like at the time of forming the alignment film is increased, and the alignment film can have sufficient alignment properties. In addition, it is preferable that the thickness is 10 占 퐉 or less because the liquid crystal cell can be made thin.

The hardness of the alignment film formed with the polyimide composition of the present invention is generally 10 or more, preferably 20 or more, and more preferably 30 or more, at Vickers hardness at a film thickness of 2 占 퐉. It is usually 100 or less, preferably 80 or less, and more preferably 60 or less. When the Vickers hardness is in a specific range, scratches are less likely to occur on the alignment film, and there is a tendency to prevent defective coating of the anisotropic dye film due to scratches on the alignment film. In addition, when the surface treatment such as rubbing treatment of the alignment film is performed, the relaxation is slowed and the surface treatment effect tends to be obtained.

The Vickers hardness can be measured as follows using a microhardness meter HM2000 (manufactured by Fisher Instruments).

The indenter is loaded with a Vickers indenter at a load of 5 mN / 占 퐉 at a load speed of 1.67 mN / sec, and after holding for 5 seconds, the load is removed to obtain Vickers hardness (Martens hardness 占 0.0945).

The elastic deformation rate of the alignment film formed with the polyimide composition of the present invention is usually 10% or more, preferably 15% or more, more preferably 18% or more, as determined by a microhardness meter at a film thickness of 2 占 퐉. Particularly preferably 20% or more. It is usually not more than 70%, preferably not more than 65%. When the rate of change in elasticity of the orientation film is in this range, it is difficult to relax the surface treatment such as rubbing, and surface treatment such as rubbing can be maintained, and orientation properties can be maintained. In addition, when rubbing is performed, the alignment film is less scored and scratched by rubbing, and a uniform alignment film tends to be obtained.

The transmittance of the alignment film made of the polyimide composition of the present invention is usually 60% or more, preferably 70% or more, more preferably 80% or more, on the longer wavelength side (visible region) than 400 nm. The upper limit of the transmittance is not particularly limited, and it is preferable that the upper limit is high.

An alignment film having a high light transmittance is preferably used in a device requiring transparency. In particular, when used in a liquid crystal display, it is preferable that the blue region of the backlight has a high transmittance, and more specifically, it is preferable that the transmittance has a longer wavelength than 420 nm. The total light transmittance in JIS K 7136-1 is used as the transmittance of the alignment film formed from the polyimide composition of the present invention.

In order to enhance the orientation characteristic of the orientation film, the coated surface obtained above is subjected to surface treatment such as rubbing treatment in which the cloth is rubbed in a predetermined direction with a cloth containing fibers such as nylon, rayon, and cotton, and treatment for irradiating linearly polarized light can do. By performing these treatments, an alignment film having higher orientation characteristics can be obtained.

Among them, it is preferable to enhance the orientation property by the rubbing treatment in order to orient the anisotropic dye film described below. When this rubbing treatment is carried out on the alignment film and the anisotropic coloring matter is oriented, it is necessary to perform rubbing treatment more strongly than that in the liquid crystal alignment film. Therefore, in the conventional alignment film for liquid crystal, scraping due to rubbing occurs, and defects of the anisotropic dye film resulting from scratching of the alignment film caused by process contamination and scraping due to scraped debris occur.

When the water-soluble dichroic dye is applied to the surface-treated alignment film, the contact angle of the alignment film is usually 70 ° or less, preferably 60 ° or less, more preferably 50 ° or less. Since the contact angle is within a suitable range, the dye solution does not bounce and the dye solution tends to be uniformly applied.

1.7 Composition for Anisotropic Pigment Film

The composition for an anisotropic coloring matter film is preferably a liquid crystal phase as a composition from the viewpoint of forming an anisotropic coloring film formed after evaporation of a solvent at a high degree. In addition, in the present embodiment, the state of the liquid crystal phase means that the state of liquid crystal and the state of crystals of liquid crystal, as described in "Fundamentals and Applications of Liquid Crystals" (Shoichi Matsumoto and Ichiro Matsumoto, 1991) A liquid crystal state indicating the properties of both, and a nematic, cholesteric, smectic or discotic state. A nematic phase is particularly preferred.

If necessary, a binder resin, a monomer, a curing agent, an additive, and the like may be added to the composition for an anisotropic coloring matter film. The composition for the anisotropic coloring matter film may be in a solution state or in a gel state. The composition for an anisotropic coloring matter film may be in a state in which a coloring matter or the like is dissolved or dispersed in a solvent.

(Coloring matter)

For the coloring matter, usually a dichroic coloring matter is used. Examples of the dichroic dye include a dye that expresses a lyotropic liquid crystal, a dye that expresses a thermotropic liquid crystal, and the like, and any of them may be used.

In the present invention, the dye is preferably a dye having a liquid crystal phase for orientation control. Here, the coloring matter having a liquid crystal phase means a coloring material showing lyotropic liquid crystallinity in a solvent, and when it is a composition for an anisotropic coloring film, a liquid crystal phase may or may not be expressed. However, .

The dye used in the present invention is preferably soluble in water or an organic solvent and is particularly preferably water-soluble so that the composition for an anisotropic coloring film develops a liquid crystal phase and is provided in a wet film formation method described later . More preferable is a compound having an inorganic value smaller than an organic value as defined in "Organic Conceptual Diagram - Fundamentals and Applications" (Yoshio Kodama, published by Sankyo Publishing Co., Ltd., 1984). In the state of glass which does not take a salt form, its molecular weight is preferably 200 or more, particularly preferably 300 or more, more preferably 1500 or less, and particularly preferably 1200 or less. Further, the water-solubility means that the compound is dissolved in water at a rate of usually 0.1 mass% or more, preferably 1 mass% or more at room temperature.

In the composition for an anisotropic dye film of the present invention, only one kind of dye may be used, or two or more kinds of dye may be used in combination. In the case of combining two or more kinds, at least one dye may be a dye that expresses a liquid crystal phase in order for the composition for an anisotropic dye film to exhibit a liquid crystal phase.

Specific examples of the colorant include an azo pigment, a stilbene pigment, a cyanine pigment, a phthalocyanine pigment, a condensed polycyclic pigment (perylene, oxazine).

The dye used in the present invention is not particularly limited, and the following known dyes can be used.

Examples of the coloring matter include, for example, JP-A-2006-079030, JP-A-2010-168570, JP-A-2007-302807, JP-A-2008-081700, JP- 230142, JP-A-2007-272211, JP-A-2007-186428, JP-A-2008-69300, JP-A-2009-169341, JP-A-2009-161722, Patent Publication Nos. 2009-173849, 2010-039154, 2010-180314, 2010-266769, 2010-031268, 2011-012152 Japanese Laid-Open Patent Publication No. 2011-016922, Japanese Laid-Open Patent Publication No. 2010-100059, Japanese Laid-Open Patent Publication No. 2011-141331, Japanese Laid-Open Patent Publication No. 2011-190313, Japanese Laid-Open Patent Publication No. 08-511109, Patent Publication No. 2001-504238, Japanese Patent Application Laid-Open No. 2006-48078, Japan Japanese Patent Application Laid-Open Nos. 2006-98927, 2006-193722, 2006-206878, 2005-255846, 2007-145995, 2007- Japanese Patent Application Laid-Open No. 126628, Japanese Laid-Open Patent Publication No. 2008-102417, Japanese Laid-Open Patent Publication No. 2012-194357, Japanese Laid-Open Patent Publication No. 2012-194297, Japanese Laid-Open Patent Publication No. 2011-034061, Japanese Laid-Open Patent Publication No. 2009-110902, Japanese Patent Laid-Open Publication No. 2001-194365, Japanese Laid-Open Patent Publication No. 2011-016920, and the like.

The coloring matter is suitable as a coloring matter for an anisotropic coloring film formed by a wet film-forming method, has a low wavelength dispersibility, and has a high degree of polarization and a high coloring ratio. In addition, since the dye is excellent in compatibility with the alignment film formed from the polyimide composition of the present invention, an anisotropic dye film exhibiting a high degree of molecular orientation tends to be obtained.

Among these dyes, it is preferable to use an azo dye because it is particularly excellent in compatibility with an alignment film formed from the polyimide composition of the present invention. The azo-based dye means a dye having at least one azo group. The number of azo groups in the molecule is preferably 2 or more, and more preferably 6 or less. Further, 4 or less is more preferable. With a suitable number of azo groups, a color tone having a low wavelength dispersibility and absorption in a wide region in the visible region is obtained, and the preparation tends to be easy.

Among the azo dyes, each dye of disazo, trisazo and tetrakisazato, which has the structure of the following general formula (A) in the form of a free acid, is excellent in compatibility with the alignment film formed from the polyimide composition of the present invention , And an anisotropic dye film exhibiting a high degree of molecular orientation can be obtained. The dye having the structure of the general formula (A) is preferable because it has a low wavelength dispersibility and a color tone having absorption in a wide region in the visible region is obtained.

[Chemical Formula 14]

Wherein in the formula (A), E ¹ represents an any organic, R ²⁰ and R ²¹ are, each independently, a phenyl group which may have an alkyl group or a substituent which may have a hydrogen atom, a substituent, p and q is independently an integer of 1 or more and 5 or less, and the sum of p and q is 2 or more and 6 or less.

Among the structures of the general formula (A), each of disazo, trisazo and tetrakisazato dyes having the structure of the general formula (B) in the form of the free acid is preferably an alignment film formed from the polyimide composition of the present invention And an anisotropic dye film exhibiting a high degree of molecular orientation can be obtained. The dye having the structure of the general formula (B) is particularly preferable because it has a low wavelength dispersibility and a color tone having absorption in the wide region in the visible region.

[Chemical Formula 15]

In the general formula (B), E ² represents an arbitrary organic group, and R ²² and R ²³ Each independently represent a hydrogen atom, an alkyl group which may have a substituent, or a phenyl group which may have a substituent.

The dye (specific compound) used in the present invention is exemplified below, but it is not limited thereto.

[Chemical Formula 16]

[Chemical Formula 17]

[Chemical Formula 18]

[Chemical Formula 19]

[Chemical Formula 20]

[Chemical Formula 21]

[Chemical Formula 22]

(23)

The coloring matter in the present embodiment may be used in the form of free acid, or a part of the acid group may take a salt form. In addition, a salt dye and a free acid dye may be mixed. In the case of a salt obtained at the time of production, it may be used as it is, or it may be converted into a desired salt form. As the exchange method of the salt type, known methods can be optionally used, and for example, the following methods can be mentioned.

1) A strong acid such as hydrochloric acid is added to an aqueous solution of a dye obtained in a salt form, the pigment is acid-precipitated in the form of free acid, and then an alkali solution (for example, an aqueous solution of lithium hydroxide) The method of salt exchange by neutralizing the group.

2) A method in which salt exchange is performed in the form of a salting-out cake by adding an excessive neutral salt (for example, lithium chloride) having a desired counter ion to an aqueous solution of a dye obtained in a salt form.

3) An aqueous solution of the dye obtained in a salt form is treated with a strongly acidic cation exchange resin, the dye is calcined in the form of a free acid, and the dye acid group is neutralized with an alkali solution having a desired counter ion (for example, an aqueous solution of lithium hydroxide) Method of salt exchange.

4) A method in which an aqueous solution of a dye obtained in a salt form is caused to act on a strongly acidic cation-exchange resin treated with an alkali solution (for example, an aqueous solution of lithium hydroxide) having a desired counter ion in advance, thereby effecting salt exchange.

Whether the acid group of the dye in the present embodiment is free acid or salt form depends on the pKa of the dye and the pH of the dye aqueous solution.

Examples of the salt form include salts of alkali metals such as Na, Li and K, salts of ammonium which may be substituted with an alkyl group or a hydroxyalkyl group, and salts of organic amines. Examples of the organic amine include a lower alkylamine having 1 to 6 carbon atoms, a hydroxy-substituted lower alkylamine having 1 to 6 carbon atoms, and a carboxy-substituted lower alkylamine having 1 to 6 carbon atoms. In the case of these salt forms, the kind thereof is not limited to one kind, and plural kinds may be mixed.

The above-mentioned dyes may be used alone, but two or more dyes may be used in combination, or dyes other than the above exemplified dyes may be blended to such an extent that the orientation is not deteriorated. Thus, an anisotropic dye film having various colors can be produced.

Examples of formulating dyes for mixing other dyes include CI Direct Yellow 12, CI Direct Yellow 34, CI Direct Yellow 86, CI Direct Yellow 142, CI Direct Yellow 132, CI Acid Yellow 25, CI Direct Orange 39, CI Direct Orange 72, CI Direct Orange 79, CI Acid Orange 28, CI Direct Red 39, CI Direct Red 79, CI Direct Red 81, CI Direct Red 83, CI Direct Red 89, Direct Violet 35, CI Direct Violet 48, CI Direct Violet 57, CI Direct Blue 1, CI Direct Blue 67, CI Direct Blue 83, CI Direct Blue 90, CI Direct Green 42, CI Direct Green 51, .

The anthraquinone compound may be added to the composition for an anisotropic dye film of the present invention according to the method described in Japanese Unexamined Patent Application Publication No. 2007-199333 and Japanese Unexamined Patent Application Publication No. 2008-101154. Also, the methods described in Japanese Unexamined Patent Application Publication No. 2006-3864 and Japanese Unexamined Patent Publication No. 2006-323377 may be used.

In the composition for an anisotropic coloring matter film of the present invention, as described in JP-A-2007-178993, the modulus of elasticity G of the composition for an anisotropic coloring film at a temperature of 5 캜 and after 0.01 seconds from the application of the deformation is reduced by a factor of 10 The defects of the anisotropic coloring matter film may be controlled by setting the time until the completion of the anisotropic dyeing step to not more than 0.1 second. Concretely, it is exemplified that the acidic group of the azoic compound in the composition for an anisotropic coloring film is contained in an amount of not less than 0.9 equivalents and not more than 0.99 equivalents and not more than 0.02 equivalents and not more than 0.1 equivalents of strongly acidic anion .

(Solvent of composition for anisotropic coloring matter film)

The solvent is not particularly limited as long as it dissolves or disperses the compound. Particularly, water, a water miscible organic solvent, or a mixture thereof is suitable, since the coloring matter easily forms a state of association with the lyotropic liquid crystal in the solvent. Specific examples of the organic solvent include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol and glycerin, glycols such as ethylene glycol and diethylene glycol, cellosolve such as methyl cellosolve and ethyl cellosolve Or a mixed solvent of two or more kinds.

Among them, water, methanol and ethanol are preferable, and water is particularly preferable from the viewpoint of promoting the association of highly organic parts such as aromatic rings of dyes.

(Concentration of coloring matter in composition for anisotropic coloring matter film)

The concentration of the colorant in the composition for an anisotropic coloring matter film may vary depending on film forming conditions, but is preferably 0.01 mass% or more, more preferably 0.1 mass% or more, and preferably 50 mass% or less, 30% by mass or less. If the concentration of the dye is excessively low, the association of the dye in the composition becomes insufficient, and anisotropy such as a sufficient degree of polarization or dichroism can not be obtained in the resulting anisotropic dye film, and if it is excessively high, viscosity becomes high, The dye may be precipitated in the composition for an anisotropic coloring matter film.

(Additive of composition for anisotropic coloring matter film)

If necessary, additives such as a surfactant, a leveling agent, a coupling agent, and a pH adjuster may be added to the composition for the anisotropic coloring matter film. In some cases, the wettability and the coatability can be improved by an additive.

As the surfactant, any of anionic, cationic and nonionic surfactants can be used. The concentration of the additive is not particularly limited, but is sufficient to obtain the added effect and is an amount that does not inhibit the orientation of the molecules. The concentration thereof in the composition for an anisotropic color film is usually 0.01 mass% or more, preferably 0.1 mass% Or more. Further, it is preferably 5 mass% or less, more preferably 1 mass% or less, particularly preferably 0.5 mass% or less.

For the purpose of suppressing instability such as salt formation and agglomeration in the composition for the anisotropic coloring matter film, it is also possible to use a known acid / alkaline pH adjusting agent or the like in combination with the constituent components of the composition for the anisotropic coloring matter film It may be added before, after, or during mixing. As additives other than the above, known additives described in "Additive for Coating", edited by J. Bieleman, Willey-VCH (2000) may be used.

1.8 Formation of anisotropic pigment film

In the present invention, it is preferable to produce an anisotropic dye film on the alignment film of the present invention by a wet film forming method.

The wet film forming method according to the present invention is a method in which a composition for an anisotropic color film is applied on an alignment film by any method and a dye or the like is oriented and laminated on a substrate through a process of drying the solvent. In the wet film-forming method, when a composition for an anisotropic coloring film is formed on a substrate, the dye itself is self-assembled in the composition for an anisotropic coloring film or in the course of drying the solvent, thereby causing orientation in a small area. By giving an external field in this state, anisotropic dye film having desired performance can be obtained by orienting the macroscopic region in a certain direction. In this respect, this method is different from a method in which a so-called polyvinyl alcohol (PVA) film is dyed and stretched with a solution containing a dye, and the dye is oriented only by the stretching process. Here, the exterior refers to the influence of the orientation treatment layer previously performed on the substrate, the shearing force, the magnetic field, and the like, and these may be used alone or in combination.

The process for forming the composition for an anisotropic coloring film on a substrate, the process for orienting and orienting the envelope, and the drying process for the solvent may be carried out in sequence or simultaneously.

Examples of the application method of the composition for an anisotropic color film in the wet film forming method on a substrate include a coating method, a dip coating method, an LB film forming method, and a known printing method. The anisotropic dye film thus obtained may be transferred to another substrate. Among them, the coating method is preferably used in the present invention. Specifically, an anisotropic dye film can be formed by applying the composition for an anisotropic dye film to an alignment film.

The orientation direction of the anisotropic dye film is usually the same as the application direction, but may be different from the application direction. In the present embodiment, the orientation direction of the anisotropic dye film is, for example, a transmission axis or an absorption axis of polarized light in the case of an anisotropic dye film, and a fast axis or a slow axis in the case of a retardation film.

The anisotropic dye film in this embodiment functions as a polarizing film or a retardation film for obtaining linearly polarized light, circularly polarized light, elliptically polarized light or the like by utilizing the anisotropy of light absorption, as well as a film forming process and a photoreceptor (substrate or the like) Or various anisotropic films such as refractive anisotropy and conductive anisotropy depending on the choice of a composition containing an organic compound (dye or transparent material).

The method for applying the composition for an anisotropic coloring film to obtain an anisotropic coloring film is not particularly limited, and for example, a method described in Harazaki et al., "Coating Technology" (published by Asakura Shoten Co., Ltd., March 20, 1971) , The method described in Ichimura Kunihiro, "Creation and Application of Molecular Coordinate Materials" (published by CMC Co., Ltd., March 3, 1998), pp. 118 to 149, a slot die coating method, A spin coating method, a spray coating method, a bar coating method, a roll coating method, a blade coating method, a curtain coating method, a fountain method, and a dipping method. Among them, the slot die coating method is preferable because an anisotropic dye film having high uniformity can be obtained.

When the composition for an anisotropic dye film which is preferable as the composition for an anisotropic dye film described above on the alignment film of the present invention is applied by the coating method described above, it is preferable that an alignment treatment such as an orientation film or the like And the shear force applied to the composition for an anisotropic coloring film upon application causes the dye to be oriented.

The supply method and supply interval of the composition for anisotropic pigment film when continuously applying the composition for an anisotropic coloring matter film are not particularly limited but the supply operation of the coating liquid may become troublesome or the coating film thickness . When the thickness of the anisotropic dye film is small, it is preferable to apply the composition while supplying the composition for the anisotropic color film in particular continuously.

The speed of applying the composition for an anisotropic color film is generally 1 mm / second or more, preferably 5 mm / second or more, and more preferably 10 mm / second or more. It is usually not more than 1000 mm / second, preferably not more than 200 mm / second. If the application speed is excessively small, the anisotropy of the anisotropic dye film may be lowered. On the other hand, if it is excessively large, there is a fear that it can not be uniformly applied.

The coating temperature of the composition for an anisotropic coloring matter film is usually 0 ° C or more and 80 ° C or less, preferably 40 ° C or less. The humidity at the time of application of the composition for an anisotropic color film is preferably 10% RH or more, more preferably 30% RH or more, and preferably 80% RH or less.

The film thickness of the anisotropic dye film is preferably 10 nm or more, and more preferably 50 nm or more, as a dry film thickness. On the other hand, it is preferably 30 占 퐉 or less, and more preferably 1 占 퐉 or less. The film thickness of the anisotropic coloring film is in an appropriate range, so that uniform orientation of molecules and uniform film thickness can be obtained in the film.

The anisotropic dye film may be subjected to an insolubilization treatment. Insolubilization means a treatment process in which the solubility of the compound in the anisotropic dye film is lowered to thereby control the elution of the compound from the anisotropic dye film to improve the stability of the film. Concretely, for example, a process in which ions of a small valence are replaced with ions of a larger valence (for example, a monovalent ion is replaced with a multivalent ion), or a treatment with an organic molecule or polymer having a plurality of ionic groups And a substitution treatment. As such a treatment method, a known method such as a treatment process described in, for example, Hosoda Yutaka, " Theoretical Preparation and Dyeing Chemistry " (preference, 1957), pp. 435 to 437 can be used.

It is preferable that the obtained anisotropic dye film is treated by the method described in JP-A-2007-241267 or the like to obtain an anisotropic dye film insoluble in water from the viewpoints of easiness in the post-process, durability and the like.

The transmittance in the visible light wavelength region of the anisotropic dye film is preferably 25% or more. More preferably 35% or more, and particularly preferably 40% or more. The upper limit of the transmittance is not particularly limited and may be an upper limit according to the application. For example, when it is used for a liquid crystal display, it is preferably 50% or less.

When the anisotropic dye film of the present invention is used as a polarizing element, the orientation characteristic of the anisotropic dye film can be indicated by the polarization. The degree of polarization is usually 95% or more at a light transmittance of 36% or more, preferably 98% or more, and more preferably 99% or more. The higher the degree of polarization, the better, and the maximum value is 100%. Since the polarization degree is equal to or larger than the value of the transfer, it is useful as the following optical element, particularly, a polarizing element.

The transmittance of each of the anisotropic dye films is not particularly limited as long as the transmittance is the same, and any wavelength may be selected according to the purpose. In the case of indicating the degree of orientation of the anisotropic dye film, the value at the maximum absorption wavelength of the anisotropic dye film is preferably used Do.

The degree of polarization P (%) = {(Ty - Tz) / (Ty + Tz)} ^1/2 100

Tz: transmittance of polarized light in the absorption axis direction of the anisotropic dye film

Ty: transmittance of polarized light in the polarization axis direction of the anisotropic dye film

The composition for anisotropic dye or anisotropic dye film may be directly added to the polyimide composition of the present invention to be used as an anisotropic dye film. Each condition in this case can be performed in the same manner as the method of forming the anisotropic dye film.

1.9 Optical elements

The optical element of the present invention is an element having functions such as a polarizing element, a phase difference element, a refractive anisotropy and a conductive anisotropy, which obtain linearly polarized light, circularly polarized light, elliptically polarized light and the like by utilizing anisotropy of light absorption. These functions can be suitably adjusted depending on the film forming process and the selection of a composition containing a donor (such as a substrate) or an organic compound (a dye or a transparent material). In the present invention, it is preferable to use it as a polarizing element.

1.10 Polarization element

The polarizing element of the present invention may have any film (layer) as long as it has an alignment film and a composition for an anisotropic dye film on a photoreceptor (substrate or the like). For example, it can be produced by forming a composition for an anisotropic coloring film on the surface of an alignment film. The polarizing element of the present invention can be used as an overcoat layer, an adhesive layer or an antireflection layer, an orientation film, a function as a retardation film, a function as a brightness enhancement film, a function as a reflection film, a function as a transflective film , A layer having optical functions such as a function as a diffusing film, or the like may be laminated and formed by coating, bonding or the like and used as a laminate.

The layer having these optical functions can be formed, for example, by the following method.

The layer having a function as a retardation film may be subjected to a stretching treatment described in, for example, Japanese Unexamined Patent Application Publication No. 2-59703 and Japanese Unexamined Patent Publication No. 4-230704 or the like as disclosed in Japanese Unexamined Patent Application Publication No. 7-230007 Followed by treatment.

The layer having a function as a brightness enhancement film can be obtained by forming fine holes by the method described in, for example, Japanese Patent Application Laid-Open No. 2002-169025 or Japanese Patent Application Laid-Open No. 2003-29030, Or by stacking two or more cholesteric liquid crystal layers.

The layer having a function as a reflective film or a transflective film can be formed using a metal thin film obtained by vapor deposition, sputtering or the like. The layer having a function as a diffusion film can be formed by coating a resin solution containing fine particles in the protective layer.

The layer having a function as a retardation film or an optical compensation film can be formed by applying a liquid crystal compound such as a discotic liquid crystal compound or a nematic liquid crystal compound and orienting the liquid crystal compound.

When the anisotropic dye film in this embodiment mode is used as an anisotropic dye film or the like on various display elements such as LCD and OLED, an orientation film and an anisotropic dye film are directly formed on the surface of an electrode substrate or the like constituting these display elements, And a substrate on which an anisotropic dye film is formed can be used as constituent members of these display elements.

The optical element of the present invention can be used not only for a liquid crystal display or an organic electroluminescence display but also for a liquid crystal projector Or a display panel for vehicle use, which is required to have high heat resistance.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The following examples are provided to illustrate the present invention in detail, and the present invention is not limited to the following examples unless it is contrary to the purpose thereof. The values of the various conditions and evaluation results in the following examples have a meaning as a preferred value of the upper limit or the lower limit in the embodiment of the present invention, and the preferable range is the value of the upper limit or the lower limit Or may be a range defined by a combination of example values or values of the embodiments.

<Directional ring element ratio>

Was calculated from the ratio of the aromatic tetracarboxylic acid anhydride to the diamine compound in the raw material monomer.

<Imidization rate>

The imidization ratio of the synthesized polyimide composition was measured using FT-IR (6100, manufactured by Nippon Bunko K.K.) as follows.

First, the polyimide composition was applied to potassium bromide crystals, and a sample dried at 300 캜 was prepared similarly to the sample dried at 70 캜.

300 ℃ absorption near 1500 ㎝ ^-1 of the dried samples (A), 1380 ㎝ ^-1 vicinity of the absorbent (B), the absorption in the vicinity of 1500 ㎝ ^-1 of 70 ℃ dry sample (A '), in the vicinity of 1380 ㎝ ^-1 The absorption (B ') was measured, and the imidization ratio (%) of each polyimide composition was calculated from the following equation.

Imidization rate = (A '/ B') / (A / B) * 100

<Availability>

The polyimide composition containing the reaction solution was judged to be &quot; x &quot; when solid content (insoluble polyimide resin) was precipitated at room temperature, and &quot; o &quot;

&Lt; Measurement of Vickers microhardness meter &

The solid content concentration of the synthesized polyimide compositions 1 to 3 was diluted to 15% by weight and used as a coating solution. 7 This coating liquid was applied to a glass substrate using a spin coater, heated at 80 占 폚 for 10 minutes, and further heated at 140 占 폚 for 1 hour. The film thickness at this time was 2 占 퐉.

The membrane was loaded with a Vickers microhardness meter HM2000 (Fisher Instruments) and an indenter using a Vickers indenter and a load of 5 mN / m &lt; 2 &gt; at a load speed of 1.67 mN / sec. And the Vickers hardness (Martens hardness x 0.0945) and the change rate of elasticity (total deformation amount - plastic deformation amount) / total deformation amount x 100 were obtained.

(Synthesis of polyimide composition)

[Example 1]

A four-necked flask equipped with a refluxing nitrogen gas introducing tube, a condenser, a Dean Stark condenser filled with toluene and a stirrer was charged with 1,1'-bicyclohexane-3,3 ', 4,4'-tetracarboxylic acid dianhydride 6.9 9.4 g of 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 58 g of N, N-dimethylacetamide and 10.7 g of toluene were added. The mixture was heated with stirring and reacted at 140-150 캜 for 13 hours to obtain polyimide composition 1.

With respect to the polyimide composition 1 thus obtained, the aromatic ring element ratio, the imidization ratio and the solubility were determined by the above-mentioned method. The results are shown in Table 1.

[Example 2]

Synthesis was carried out in the same manner as in Example 1 except that 2,2-bis (4- (4-aminophenoxy) phenyl) propane of Example 1 was changed to 4.6 g of 4,4'-diaminodiphenyl ether, Thus, polyimide composition 2 was obtained. The obtained polyimide composition 2 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 3]

Except that 2,2-bis (4- (4-aminophenoxy) phenyl) propane of Example 1 was changed to 4.8 g of 4,4'-diamino-2,2'-dimethylbiphenyl, 1, to obtain a polyimide composition 3. The obtained polyimide composition 3 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 4]

In a four-necked flask equipped with a refluxing nitrogen gas introducing tube, a condenser, a Deanstock condenser filled with toluene and a stirrer, 13.3 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1.5 g of pyromellitic dianhydride 1.5 14.0 g of 3,4-diaminodiphenyl ether, 86 g of N-methyl-2-pyrrolidone and 17.3 g of toluene were added. The mixture was heated with stirring and reacted at 160 to 170 ° C for 13 hours to obtain polyimide composition 4. The obtained polyimide composition 4 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 5]

The 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride of Example 4 was dissolved in 15.714 g of 3,3 ', 4,4'-biscyclohexanetetracarboxylic dianhydride, and 3,4-diamino 25.949 g of bis (4- (4-aminophenoxy) phenyl) sulfone, 1.243 g of pyromellitic dianhydride, 82 g of N-methyl-2-pyrrolidone, 16.3 g , Respectively, to obtain a polyimide composition 5. The obtained polyimide composition 5 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 6]

The 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride of Example 4 was mixed with 9.982 g of 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride and 0 g of pyromellitic anhydride, Diaminodiphenyl ether was changed to 10.012 g, N-methyl-2-pyrrolidone was changed to 60 g, and toluene was changed to 12 g, respectively, to obtain a poly Meid Composition 6 was obtained. The obtained polyimide composition was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 7]

The 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride of Example 4 was reacted with 12.63 g of 1,1'-bicyclohexane-3,3 ', 4,4'-tetracarboxylic dianhydride, Except that the pyromellitic anhydride was changed to 1.0 g, 3,4-diaminodiphenyl ether was changed to 9.66 g, N-methyl-2-pyrrolidone was changed to 70.10 g, and toluene was changed to 10.5 g, 4, a polyimide composition 7 was obtained. The obtained polyimide composition 7 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]

The 1,1'-bicyclohexane-3,3 ', 4,4'-tetracarboxylic dianhydride of Example 2 was reacted with 6.7 g of 3,3', 4,4'-biphenyltetracarboxylic dianhydride , The procedure of Example 2 was repeated to obtain a polyimide composition 8. The obtained polyimide composition 8 was subjected to measurement in the same manner as in Example 1. Polyimide composition 8 was not soluble. Also, the imidization rate could not be measured because it was not available. The results are shown in Table 1.

[Comparative Example 2]

The 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride of Example 4 was mixed with 4.2 g of 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 0 g of pyromellitic dianhydride , 3,4-diaminodiphenyl ether was changed to 4.8 g of 4,4-diamino-2,2-dimethylbiphenyl, 27 g of N-methyl-2-pyrrolidone and 5.4 g of toluene , The procedure of Example 4 was repeated to give a polyimide composition 9. The polyimide composition 9 thus obtained was subjected to measurement in the same manner as in Example 1. Polyimide composition 9 was not available. Also, the imidization rate could not be measured because it was not available. The results are shown in Table 1.

The compositions 1 to 3 obtained in Examples 1 to 3 were measured for Vickers hardness and elasticity according to the method of <Vickers microhardness meter>. The results are shown in Table 2.

(Preparation of alignment film)

[Examples 8 to 14]

Using the polyimide compositions 2 to 7 synthesized in Examples 2 to 7, alignment films 1 to 7 were produced as follows. Further, rubbing treatment was performed on each of the alignment films, and scratches and scratches of the film after rubbing were visually observed. The samples without scratching were evaluated as &quot; o &quot;, and those with scratches were evaluated as x.

Further, in the compositions 8 and 9 of Comparative Examples 1 and 2, since the composition was not soluble and polyimide precipitated, the coating could not be applied and an alignment film could not be obtained.

(1) Preparation of orientation film

Polyimide compositions 2 and 3 were diluted to 4% by mass with a coating solvent (N, N-dimethylacetamide) to prepare a coating liquid. Polyimide Compositions 4 to 7 were prepared by using a coating solvent (N-methyl-2-pyrrolidone / anisole = 1/1), polyimide compositions 4 and 5 of 4 mass%, polyimide composition 6 of 10 And the polyimide composition 7 was diluted to 3% by mass, respectively, to prepare a coating liquid. These coating liquids were each applied to a glass substrate using a spin coater. Thereafter, the resultant was heated at 80 占 폚 for 10 minutes and then heated at 140 占 폚 for 1 hour to obtain alignment films 1-7.

(2) Rubbing treatment

The prepared orientation films 1 to 7 were subjected to rubbing in one direction using a rayon cloth.

The compositions for anisotropic dye films were applied to the rubbed alignment films 1 to 7, respectively, and the optical characteristics of the obtained anisotropic dye films were evaluated.

(3) Application of composition for anisotropic pigment film

20 parts by mass of the azo compound represented by the formula (I) and 1 part by mass of the compound represented by the formula (II) were added to 79 parts by mass of water and dissolved by stirring to remove the insoluble matter thereby obtaining an aqueous solution of an anisotropic dye Film composition).

<Application of applicator>

The composition for anisotropic dye film was applied to a polyimide alignment film prepared by the above method with an applicator having a gap of 4 占 퐉 (manufactured by Hotta Corporation) and dried naturally to obtain an anisotropic dye film.

&Lt; Dicote coating &gt;

The composition for an anisotropic dye film was coated on the polyimide alignment film prepared by the above method using a die coater having a slot width of 50 탆 and dried naturally to obtain an anisotropic dye film.

&Lt; EMI ID =

(4) Optical performance

The optical performance was evaluated by the basic transmittance and polarized light of the anisotropic dye film. The bulk transmittance and the degree of polarization were obtained using a spectrophotometer equipped with a Glan-Thompson polarizer (product name "RETS-100" manufactured by Otsuka Electronics Co., Ltd.). The measurement light of linearly polarized light was incident on the anisotropic dye film, and the transmittance was measured. The transmittance was then calculated by the following equation to calculate the degree of polarization at 620 nm which is the maximum absorption wavelength of the anisotropic dye film.

The degree of polarization P (%) = {(Ty - Tz) / (Ty + Tz)} ^1/2 100

Tz: transmittance of polarized light in the absorption axis direction of the anisotropic dye film

Ty: transmittance of polarized light in the polarization axis direction of the anisotropic dye film

The following evaluation was made from the group transmittance and the degree of polarization.

A: It has a unit transmittance of 40% or more and a polarization degree of 99.5% or more

B: Bulk transmittance of 36% or more and a degree of polarization of 99% or more

C: Covalent transmittance of 36% or more and a degree of polarization of 95% or more and less than 99%

D: a unit transmittance of 36% or more and a polarization degree of less than 95%

The evaluation of the alignment film is shown in Tables 3 and 4.

All of Examples 1 to 7 (polyimide compositions 1 to 7) were soluble.

In addition, the alignment films 1 to 7 obtained by using the compositions 2 to 7 did not show scratches or scraping due to rubbing, and showed excellent surface treatment properties.

Further, since alignment films 1 to 7 are excellent in optical characteristics of the anisotropic dye film, it can be seen that the alignment film of the present invention has a high alignment property.

Although the present invention has been described in detail with reference to specific embodiments thereof, it is apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. The present application is based on Japanese Patent Application (Japanese Patent Application 2013-210392) filed on October 7, 2013 and Japanese Patent Application (Japanese Patent Application 2014-064536) filed on March 26, 2014, It is hereby incorporated by reference.

Industrial availability

Although the present invention can be used in any field in industry, it can be preferably used in the field where, for example, an orientation film having a high-grade property is required. Specifically, for example, Can be used particularly preferably.

Claims (5)

A polyimide composition for use in an alignment film for an anisotropic coloring film,
The polyimide composition comprises a polyimide and a solvent,
Wherein the polyimide is represented by the general formula (1).
[Chemical Formula 1]

(In the general formula (1), X represents a tetravalent aliphatic hydrocarbon group having 5 or more carbon atoms,
R ¹ represents a divalent organic group having an aromatic ring,
n represents an integer of 1 or more, and when n is 2 or more, a plurality of R ¹ and X in a single molecule of the structure represented by the general formula (1) may be the same or different. The method according to claim 1,
Wherein the ratio of the number of elements forming the aromatic ring in the number of elements forming the main chain of the polyimide is 5% or more and 75% or less. 3. The method according to claim 1 or 2,
Wherein the polyimide has an imidization ratio of 90% or more. An alignment film for an anisotropic coloring film which is formed using the polyimide composition according to any one of claims 1 to 3. An optical element having the anisotropic dye film alignment film according to claim 4 and an anisotropic dye film laminated on the alignment film for the anisotropic dye film.