TWI776960B - Polyimide resin, polyimide varnish and polyimide film - Google Patents

Abstract

This invention provides a polyimide resin comprising a constituting unit A derived from a tetracarboxylic acid dianhydride and a constituting unit B derived from a diamine, wherein the constituting unit A contains a constituting unit (A-1) derived from a compound represented by the following formula (a-1) and a constituting unit (A-2) derived from a compound represented by the following formula (a-2), and the constituting unit B contains a constituting unit (B-1) derived from a compound represented by the following formula (b-1).

Description

Polyimide resin, polyimide varnish and polyimide film

The present invention relates to polyimide resins, polyimide varnishes and polyimide films.

In recent years, with the advent of a highly information-based society, materials with both heat resistance and colorless transparency are required in the field of optical communication such as optical fibers and optical waveguides, and in the field of display devices such as liquid crystal alignment films and color filters. In the field of display devices, in order to reduce the weight and flexibility of the device, it is discussed to replace the glass substrate used in the device with a lightweight and flexible plastic substrate. In the case where the light emitted from the display element passes through the plastic substrate and is emitted, the plastic substrate is required to be colorless and transparent. Further, in the case where the light passes through the retardation film and the polarizing plate (for example, liquid crystal display, touch panel, etc.), then In addition to the requirement of colorless transparency, high optical isotropy is also required.

The development of polyimide resins is in progress as a plastic material that can meet the above-mentioned requirements. For example, Patent Document 1 discloses the use of 1,2,4,5-cyclohexanetetracarboxylic dianhydride as a tetracarboxylic acid as a polyimide resin having excellent transparency, heat resistance, and optical isotropy. acid component, and a polyimide resin or the like synthesized using 9,9-bis(3-methyl-4-aminophenyl)perylene and 4,4'-diaminodiphenyl ether as a diamine component.

In addition, in the field of microelectronics in recent years, a laser lift-off process called laser lift-off (LLO) has been widely used as a method of peeling off the resin film-laminated support from the resin film. Attention. Therefore, in order to make the polyimide film compatible with the laser peeling process, the laser peelability is also required for the polyimide film. The polyimide film is required to be excellent in absorbing light at a wavelength of 308 nm (that is, a low transmittance of light at a wavelength of 308 nm) in order to be able to cope with the lift-off processing by the XeCl excimer laser at a wavelength of 308 nm. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 6010533

[The problem to be solved by the invention]

The present invention is made in view of the above-mentioned circumstances, and an object of the present invention is to provide a polyimide resin excellent in colorless transparency, optical isotropy, and laser releasability. [Means of Solving Problems]

The inventors of the present invention found that a polyimide resin containing a combination of specific structural units can solve the above-mentioned problems, and completed the invention.

That is, the present invention relates to the following [1] to [8]. [1] A polyimide resin comprising a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from a diamine; The structural unit A contains the structural unit (A-1) derived from the compound represented by the following formula (a-1), and the structural unit (A-2) derived from the compound represented by the following formula (a-2); The structural unit B contains the structural unit (B-1) derived from the compound represented by the following formula (b-1).

[hua 1]

In formula (b-1), R is each independently a hydrogen atom, a fluorine atom or a methyl group.

[2] The polyimide resin according to the above [1], wherein the ratio of the structural unit (A-1) in the structural unit A is 10 to 90 mol %, and the structural unit (A-2) in the structural unit A is 10 to 90 mol %. ) in a ratio of 10 to 90 mol%. [3] The polyimide resin according to the above [1] or [2], wherein the ratio of the structural unit (B-1) in the structural unit B is 30 to 100 mol %. [4] The polyimide resin according to any one of the above [1] to [3], wherein the structural unit B further contains a structural unit (B-2), and the structural unit (B-2) is selected from the group consisting of The structural unit (B-2-1) of the compound represented by the following formula (b-2-1), the structural unit (B-2-2) derived from the compound represented by the following formula (b-2-2), and the At least one of the group consisting of the structural unit (B-2-3) of the compound represented by the formula (b-2-3).

[hua 2]

In formula (b-2-3), R ₁ to R ₄ are each independently a monovalent aliphatic group or a monovalent aromatic group, and Z ₁ and Z ₂ are each independently a divalent aliphatic group or a divalent aromatic group base, r is a positive integer.

[5] The polyimide resin according to the above [4], wherein the ratio of the structural unit (B-1) in the structural unit B is 30 to 95 mol %, and the structural unit (B-2) in the structural unit B ) in a ratio of 5 to 70 mol%. [6] The polyimide resin according to any one of the above [1] to [5], wherein R represents a hydrogen atom. [7] A polyimide varnish prepared by dissolving the polyimide resin according to any one of the above [1] to [6] in an organic solvent. [8] A polyimide film comprising the polyimide resin according to any one of the above [1] to [6]. [Effect of invention]

The polyimide resin of the present invention is excellent in colorless transparency, optical isotropy, and laser releasability.

[Polyimide resin] The polyimide resin of the present invention contains a structural unit A derived from a tetracarboxylic dianhydride and a structural unit B derived from a diamine, and the structural unit A contains a structural unit (A- 1) With the structural unit (A-2) derived from the compound represented by the following formula (a-2), the structural unit B contains the structural unit (B-1) derived from the compound represented by the following formula (b-1).

[hua 3]

In formula (b-1), R is each independently a hydrogen atom, a fluorine atom or a methyl group.

<Construction Unit A> The structural unit A is a structural unit derived from tetracarboxylic dianhydride, and contains a structural unit (A-1) derived from a compound represented by formula (a-1) and a structural unit (A-) derived from a compound represented by formula (a-2). 2). By the structural unit (A-1), colorless transparency is improved, and by the structural unit (A-2), heat resistance, optical isotropy, and laser peelability are improved. The compound represented by formula (a-1) is 1,2,4,5-cyclohexanetetracarboxylic dianhydride. The compound represented by formula (a-2) is 9,9'-bis(3,4-dicarboxyphenyl)indianhydride.

The ratio of the constituent unit (A-1) in the constituent unit A is preferably 10 to 90 mol %, more preferably 25 to 75 mol %, and still more preferably 40 to 60 mol %. The ratio of the constituent unit (A-2) in the constituent unit A is preferably 10-90 mol %, more preferably 25-75 mol %, and still more preferably 40-60 mol %. The content ratio of the total of the structural unit (A-1) and the structural unit (A-2) in the structural unit A is preferably 20 mol % or more, more preferably 50 mol % or more, particularly preferably 80 mol % or more . The upper limit of the content ratio of the total of the structural unit (A-1) and the structural unit (A-2) is not particularly limited, that is, 100 mol %. The structural unit A may be composed of only the structural unit (A-1) and the structural unit (A-2).

The structural unit A may contain structural units other than the structural units (A-1) and (A-2). The tetracarboxylic dianhydride forming such a structural unit is not particularly limited, and examples thereof include pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, and 4,4'- Aromatic tetracarboxylic dianhydrides such as (hexafluoroisopropylidene)diphthalic anhydride (except compounds represented by formula (a-2)); 1,2,3,4-cyclobutanetetracarboxylic acid Alicyclic dianhydride, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride, etc. tetracarboxylic dianhydrides (except compounds represented by formula (a-1)); and aliphatic tetracarboxylic dianhydrides such as 1,2,3,4-butane tetracarboxylic dianhydride. In addition, in this specification, aromatic tetracarboxylic dianhydride means tetracarboxylic dianhydride containing one or more aromatic rings; alicyclic tetracarboxylic dianhydride means containing one or more alicyclic rings, and Tetracarboxylic dianhydride without aromatic ring; Aliphatic tetracarboxylic dianhydride means tetracarboxylic dianhydride without aromatic ring and alicyclic. The structural unit (that is, structural unit other than structural unit (A-1) and (A-2)) arbitrarily contained in structural unit A may be one type or two or more types.

<Construction unit B> The structural unit B is a structural unit derived from a diamine, and contains a structural unit (B-1) derived from the compound represented by the formula (b-1). Heat resistance, optical isotropy, and laser peelability are improved by the structural unit (B-1).

In formula (b-1), each R is independently selected from the group consisting of a hydrogen atom, a fluorine atom, and a methyl group, and is preferably a hydrogen atom. The compounds represented by the formula (b-1) include 9,9-bis(4-aminophenyl) fluoride, 9,9-bis(3-fluoro-4-aminophenyl) fluoride, and 9,9 -Bis(3-methyl-4-aminophenyl) fluoride, etc., preferably 9,9-bis(4-aminophenyl) fluoride.

The ratio of the constituent unit (B-1) in the constituent unit B is preferably 30 to 100 mol %, more preferably 30 to 95 mol %, and still more preferably 40 to 90 mol %. The structural unit B may be constituted by only the structural unit (B-1).

The structural unit B may contain a structural unit other than the structural unit (B-1), and it is preferable to further contain a structural unit (B-2-1) selected from the compound represented by the following formula (b-2-1), from the following The group consisting of the structural unit (B-2-2) of the compound represented by the formula (b-2-2) and the structural unit (B-2-3) derived from the compound represented by the following formula (b-2-3) At least one of the structural units (B-2).

[hua 4]

In formula (b-2-3), R ₁ to R ₄ are each independently a monovalent aliphatic group or a monovalent aromatic group, and Z ₁ and Z ₂ are each independently a divalent aliphatic group or a divalent aromatic group base, r is a positive integer.

The compound represented by the formula (b-2-1) is bis(4-aminophenyl) benzene. The compound represented by formula (b-2-2) is 2,2'-bis(trifluoromethyl)benzidine. R ₁ , R ₂ , R ₃ and R ₄ in formula (b-2-3) each independently represent a monovalent aliphatic group or a monovalent aromatic group, which may also be substituted with a fluorine atom. The monovalent aliphatic group includes a monovalent saturated hydrocarbon group or a monovalent unsaturated hydrocarbon group. The monovalent saturated hydrocarbon group includes an alkyl group having 1 to 22 carbon atoms, for example, a methyl group, an ethyl group, and a propyl group. The monovalent unsaturated hydrocarbon group includes an alkenyl group having 2 to 22 carbon atoms, and examples thereof include a vinyl group and a propenyl group. The monovalent aromatic group may be exemplified by an aryl group having 6 to 24 carbon atoms, an aralkyl group, and the like. For R ₁ , R ₂ , R ₃ and R ₄ , methyl or phenyl are especially preferred. Moreover, Z ₁ and Z ₂ each independently represent a divalent aliphatic group or a divalent aromatic group, and these groups may be substituted with a fluorine atom. The divalent aliphatic group includes a divalent saturated hydrocarbon group or a divalent unsaturated hydrocarbon group. The divalent saturated hydrocarbon group includes an alkylene group having 1 to 22 carbon atoms, for example, a methylene group, an ethylidene group, and a propylidene group. Examples of the divalent unsaturated hydrocarbon group include unsaturated hydrocarbon groups having 2 to 22 carbon atoms, and examples thereof include vinylidene groups, propenylene groups, and alkylene groups having unsaturated double bonds at the terminals. Examples of the divalent aromatic group include a phenylene group having 6 to 24 carbon atoms, a phenylene group substituted with an alkyl group, an aralkylene group, and the like. As for Z ₁ and Z ₂ , propylidene, phenylene and aralkylene are especially suitable. In addition, r represents a positive integer, and is preferably an integer of 10 to 10,000. Commercial products of the compound represented by the formula (b-2-3) include "X-22-9409", "X-22-1660B", "X-22-9409", "X-22-1660B", "Shin-Etsu Chemical Industry Co., Ltd."X-22-161AS","X-22-161A","X-22-161B", etc.

The structural unit (B-2-1) is preferable from the viewpoint of improving colorless transparency. The structural unit (B-2-2) is preferable from the viewpoint of improving colorless transparency and from the viewpoint of imparting low water absorption. The structural unit (B-2-3) is preferable from the viewpoint of imparting optical isotropy and low water absorption. In addition, the low water absorption polyimide resin has good hygroscopic dimensional stability.

When the structural unit B contains the structural unit (B-1) and the structural unit (B-2), the ratio of the structural unit (B-1) in the structural unit B is preferably 30~95 mol%, more preferably 40~90 mol% The ratio of the constituent unit (B-2) in the constituent unit B is preferably 5-70 mol %, more preferably 10-60 mol %. The content ratio of the total of the structural unit (B-1) and the structural unit (B-2) in the structural unit B is preferably 35 mol % or more, more preferably 50 mol % or more. The upper limit of the content ratio of the total of the structural unit (B-1) and the structural unit (B-2) is not particularly limited, that is, 100 mol %. The structural unit B may be composed of only the structural unit (B-1) and the structural unit (B-2).

The structural unit (B-2) may be only the structural unit (B-2-1), only the structural unit (B-2-2), or only the structural unit (B-2-3). In addition, the structural unit (B-2) may be a combination of the structural unit (B-2-1) and the structural unit (B-2-2), or may be the structural unit (B-2-2) and the structural unit (B-2-2). The combination of -2-3) may be a combination of the structural unit (B-2-1) and the structural unit (B-2-3). Moreover, the structural unit (B-2) may be a combination of the structural unit (B-2-1), the structural unit (B-2-2), and the structural unit (B-2-3).

The structural unit arbitrarily included in the structural unit B (that is, the structural unit other than the structural unit (B-1)) is not limited to the above-mentioned structural unit (B-2). The diamine that forms such an arbitrary structural unit is not particularly limited, and examples thereof include 1,4-phenylenediamine, p-xylylenediamine, 3,5-diaminobenzoic acid, and 2,2'-dimethyl Biphenyl-4,4'-diamine, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 2,2-bis(4-aminophenyl)hexa Fluoropropane, 4,4'-diaminobenzidine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indene-5- Amine, α,α'-bis(4-aminophenyl)-1,4-dicumene, N,N'-bis(4-aminophenyl)terephthalamide, 4,4 '-Bis(4-aminophenoxy)biphenyl, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and 2,2-bis(4-(4-amine) Aromatic diamines such as phenylphenoxy) phenyl) hexafluoropropane (only, the compound represented by the formula (b-1), the compound represented by the formula (b-2-1), the compound represented by the formula (b-2-2) 1,3-bis(aminomethyl)cyclohexane and 1,4-bis(aminomethyl)cyclohexane and other alicyclic Diamines; and aliphatic diamines such as ethylenediamine and hexamethylenediamine (except for compounds represented by formula (b-2-3)). In addition, in this specification, an aromatic diamine means a diamine containing one or more aromatic rings; an alicyclic diamine means a diamine containing one or more alicyclic rings and no aromatic ring; aliphatic diamines The aliphatic diamine means a diamine containing neither an aromatic ring nor an alicyclic ring. The structural unit (that is, a structural unit other than (B-1)) arbitrarily contained in the structural unit B may be one type or two or more types.

The number average molecular weight of the polyimide resin of the present invention is preferably 5,000 to 100,000 in consideration of the mechanical strength of the obtained polyimide film. Moreover, the number average molecular weight of a polyimide resin can be calculated|required from the standard polymethyl methacrylate (PMMA) conversion value measured by gel filtration chromatography, for example.

The polyimide resin of the present invention is excellent in colorless transparency, optical isotropy, and laser releasability, and therefore may have the following physical property values.

When the polyimide resin of the present invention is made into a polyimide film with a thickness of 10 μm, the total light transmittance is preferably 85% or more, more preferably 86% or more, particularly preferably 87% or more, and particularly preferably 88% or more. When the polyimide resin of the present invention is made into a polyimide film with a thickness of 10 μm, the yellowness index (YI) is preferably 3.0 or less, more preferably 2.4 or less, particularly preferably 2.0 or less, and particularly preferably 1.8 or less.

When the polyimide resin of the present invention is made into a polyimide film with a thickness of 10 μm, the absolute value of the thickness retardation (R th) is preferably 100 nm or less, more preferably 85 nm or less, particularly preferably 60 nm or less, particularly preferably 45nm or less.

When the polyimide resin of the present invention is made into a polyimide film with a thickness of 10 μm, the light transmittance at a wavelength of 308 nm is preferably 1.0% or less, more preferably 0.8% or less, particularly preferably 0.5% or less, particularly preferably Below 0.3%. The smaller the light transmittance at the wavelength of 308 nm, the better the laser peelability by the XeCl excimer laser at the wavelength of 308 nm. In addition, the total linear light transmittance, yellow index (YI), thickness retardation (Rth), and light transmittance at a wavelength of 308 nm in the present invention can be specifically measured by the methods described in the examples.

Moreover, the polyimide resin of one aspect of this invention has low water absorption. Therefore, the water absorption rate is preferably 2.5% or less, more preferably 2.0% or less, particularly preferably 1.5% or less, and particularly preferably 1.2% or less. In addition, the water absorption rate in this invention can be measured specifically by the method described in an Example.

[Manufacturing method of polyimide resin] The polyimide resin of the present invention can be prepared by containing a tetracarboxylic acid component that provides the compound providing the above-mentioned structural unit (A-1) and the compound providing the above-mentioned structural unit (A-2), and contains the above-mentioned structural unit (A-2). It is produced by reacting the diamine component of the compound of B-1).

The compound that provides the structural unit (A-1) includes the compound represented by the formula (a-1), but it is not limited thereto, and a derivative thereof may also be used as long as the same structural unit can be formed. Examples of the derivatives include tetracarboxylic acids (that is, 1,2,4,5-cyclohexanetetracarboxylic acid) corresponding to the tetracarboxylic dianhydride represented by the formula (a-1), and derivatives of the tetracarboxylic acids. Alkyl ester. The compound providing the structural unit (A-1) is preferably a compound represented by the formula (a-1) (ie, dianhydride). The compound that provides the structural unit (A-2) includes the compound represented by the formula (a-2), but it is not limited thereto, and a derivative thereof may also be used within the scope of forming the same structural unit. Examples of the derivatives include tetracarboxylic acids corresponding to the tetracarboxylic dianhydride represented by the formula (a-2), and alkyl esters of the tetracarboxylic acids. The compound providing the structural unit (A-2) is preferably a compound represented by the formula (a-2) (ie, dianhydride).

The compound that provides the structural unit (B-1) includes the compound represented by the formula (b-1), but it is not limited thereto, and a derivative thereof may also be used insofar as the same structural unit can be formed. Examples of the derivatives include diisocyanates corresponding to the diamines represented by the formula (b-1). The compound providing the structural unit (B-1) is preferably a compound represented by the formula (b-1) (ie, a diamine).

The tetracarboxylic acid component preferably contains 10-90 mol % of the compound providing the constituent unit (A-1), more preferably 25-75 mol %, and particularly preferably 40-60 mol %. The tetracarboxylic acid component preferably contains 10-90 mol % of the compound providing the constituent unit (A-2), more preferably 25-75 mol %, particularly preferably 40-60 mol %. The tetracarboxylic acid component preferably contains 20 mol % or more of the compound providing the structural unit (A-1) and the compound providing the structural unit (A-2) in total, more preferably 50 mol % or more, particularly preferably 50 mol % or more. more than 80%. The upper limit of the content ratio of the total of the compound providing the structural unit (A-1) and the compound providing the structural unit (A-2) is not particularly limited, that is, 100 mol %. The tetracarboxylic acid component may consist of only the compound providing the structural unit (A-1) and the compound providing the structural unit (A-2).

The tetracarboxylic acid component may contain compounds other than the compound providing the structural unit (A-1) and the compound providing the structural unit (A-2), and examples of the compound include the above-mentioned aromatic tetracarboxylic dianhydride, alicyclic tetracarboxylic acid Carboxylic dianhydrides, aliphatic tetracarboxylic dianhydrides, and derivatives thereof (tetracarboxylic acids, alkyl esters of tetracarboxylic acids, etc.). The compound (that is, the compound other than the compound which provides a structural unit (A-1) and the compound which provides a structural unit (A-2)) arbitrarily contained in a tetracarboxylic-acid component may be 1 type or 2 or more types.

The diamine component preferably contains 30-100 mol % of the compound providing the constituent unit (B-1), more preferably 30-95 mol %, and particularly preferably 40-90 mol %. The diamine component may be composed of only the compound that provides the structural unit (B-1).

The diamine component may contain a compound other than the compound providing the structural unit (B-1), and it is preferable to further contain the compound providing the structural unit (B-2). The compound that provides the structural unit (B-2) includes the compound represented by the formula (b-2-1), the compound represented by the formula (b-2-2), and the compound represented by the formula (b-2-3), However, it is not limited to this, and derivatives thereof may also be obtained within the scope of forming the same structural unit. Examples of the derivatives include diisocyanates corresponding to diamines represented by formula (b-2-1) to formula (b-2-3). The compound that provides the structural unit (B-2) is preferably a compound (that is, a diamine) represented by the formula (b-2-1) to the formula (b-2-3).

When the diamine component contains the compound providing the structural unit (B-1) and the compound providing the structural unit (B-2), the diamine component preferably contains 30 to 95 mol% of the compound providing the structural unit (B-1), More preferably, it contains 40-90 mol %, and preferably contains 5-70 mol % of the compound providing the constituent unit (B-2), more preferably 10-60 mol %. The diamine component is preferably contained in a total of 35 mol% or more of the compound providing the structural unit (B-1) and the compound providing the structural unit (B-2), more preferably 50 mol% or more. The upper limit of the content ratio of the total of the compound providing the structural unit (B-1) and the compound providing the structural unit (B-2) is not particularly limited, that is, 100 mol %. The diamine component may consist of only the compound providing the structural unit (B-1) and the compound providing the structural unit (B-2).

In addition, the compound (that is, a compound other than the compound which provides a structural unit (B-1)) arbitrarily contained in a diamine component is not limited to the compound which provides a structural unit (B-2). Such arbitrary compounds include the above-mentioned aromatic diamines, alicyclic diamines, and aliphatic diamines, and derivatives thereof (diisocyanates, etc.). The compound (that is, the compound other than the compound which provides a structural unit (B-1)) arbitrarily contained in a diamine component may be 1 type, and may be 2 or more types.

In the present invention, in terms of the feeding amount ratio of the tetracarboxylic acid component and the diamine component used in the production of the polyimide resin, the diamine component is preferably 0.9 to 1.1 mol relative to 1 mol of the tetracarboxylic acid component. Ear.

Moreover, in this invention, in addition to the said tetracarboxylic-acid component and a diamine component, you may use a terminal blocking agent for manufacture of a polyimide resin. The end-capping agents are preferably monoamines or dicarboxylic acids. The feed amount of the introduced end-capping agent is preferably 0.0001-0.1 mol, preferably 0.001-0.06 mol, relative to 1 mol of the tetracarboxylic acid component. For monoamine end-capping agents, for example, recommended: methylamine, ethylamine, propylamine, butylamine, benzylamine, 4-methylbenzylamine, 4-ethylbenzylamine, 4-dodecylbenzylamine, 3-methylbenzylamine, 3-ethylbenzylamine, aniline, 3-methylaniline, 4-methylaniline, etc. Among these, benzylamine and aniline can be preferably used. The dicarboxylic acid type end-capping agent is preferably a dicarboxylic acid type, and a part thereof may form a closed ring. For example, recommended: phthalic acid, phthalic anhydride, 4-chlorophthalic acid, tetrafluorophthalic acid, 2,3-benzophenone dicarboxylic acid, 3,4-benzophenone dicarboxylic acid, cyclic Hexane-1,2-dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, etc. Among these, phthalic acid and phthalic anhydride can be preferably used.

The method in particular of making the said tetracarboxylic-acid component and diamine component react is not restrict|limited, A well-known method can be used. Specific reaction methods include: (1) adding a tetracarboxylic acid component, a diamine component, and a reaction solvent to a reactor, stirring at room temperature to 80° C. for 0.5 to 30 hours, and then heating up and performing the reaction. The method for imidization reaction; (2) after adding the diamine component and the reaction solvent into the reactor and making it dissolved, add the tetracarboxylic acid component, and stir at room temperature ~ 80 ° C for 0.5 ~ 30 hours as needed, and then (3) The tetracarboxylic acid component, the diamine component, and the reaction solvent are added to the reactor, the temperature is raised immediately, and the imidization reaction is carried out.

The reaction solvent used for the production of the polyimide resin may be one that does not interfere with the imidization reaction and can dissolve the produced polyimide. For example, an aprotic solvent, a phenol type solvent, an ether type solvent, a carbonate type solvent, etc. are mentioned.

Specific examples of the aprotic solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactamide, 1,3-dimethylimidazolidinone, tetramethylurea and other amide-based solvents; γ-butyrolactone, γ-valerolactone and other lactone-based solvents; hexamethylphosphoric acid amide, hexamethylphosphine Phosphorus-containing amide-based solvents such as amide; sulfur-containing solvents such as dimethyl sulfoxide, dimethyl sulfoxide, and cyclobutane; ketone-based solvents such as acetone, cyclohexanone, and methylcyclohexanone; picoline , amine-based solvents such as pyridine; ester-based solvents such as acetic acid (2-methoxy-1-methylethyl ester), etc.

烷等。 又，碳酸酯系溶劑的具體例可列舉：碳酸二乙酯、碳酸甲基乙酯、碳酸伸乙酯、碳酸伸丙酯等。 上述反應溶劑之中，宜為醯胺系溶劑或內酯系溶劑。又，上述反應溶劑可單獨使用或將2種以上混合使用。Specific examples of the phenolic solvent include: phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol -Xylenol, 3,4-Xylenol, 3,5-Xylenol, etc. Specific examples of the ether-based solvent include 1,2-dimethoxyethane, bis(2-methoxyethyl)ether, 1,2-bis(2-methoxyethoxy)ethane, Bis[2-(2-methoxyethoxy)ethyl]ether, tetrahydrofuran, 1,4-bis

alkane etc. Moreover, as a specific example of a carbonate-type solvent, diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, propylene carbonate, etc. are mentioned. Among the above-mentioned reaction solvents, an amide-based solvent or a lactone-based solvent is preferable. Moreover, the said reaction solvent can be used individually or in mixture of 2 or more types.

For the imidization reaction, a Dean-Stark apparatus or the like is preferably used, and the reaction is carried out while removing water generated during production. By performing such an operation, the degree of polymerization and the imidization rate can be further increased.

In the above imidization reaction, a known imidization catalyst can be used. As the imidization catalyst, an alkali catalyst or an acid catalyst can be mentioned. Examples of the base catalyst include: pyridine, quinoline, isoquinoline, α-picoline, β-picoline, 2,4-lutidine, 2,6-lutidine, trimethylamine, triethyl Amine, tripropylamine, tributylamine, triethylenediamine, imidazole, N,N-dimethylaniline, N,N-diethylaniline and other organic base catalysts; potassium hydroxide or sodium hydroxide, potassium carbonate, Inorganic alkali catalysts such as sodium carbonate, potassium bicarbonate, and sodium bicarbonate. Moreover, as an acid catalyst, crotonic acid, acrylic acid, trans-3-hexenoic acid, cinnamic acid, benzoic acid, toluic acid, hydroxybenzoic acid, terephthalic acid, benzenesulfonic acid, p-toluenesulfonic acid can be mentioned. , naphthalene sulfonic acid, etc. The above-mentioned imidization catalysts may be used alone or in combination of two or more. Among the above, from the viewpoint of operability, an alkali catalyst is preferably used, an organic alkali catalyst is more preferably used, triethylamine is particularly preferably used, and triethylamine and triethylenediamine are particularly preferably used in combination.

The temperature of the imidization reaction is preferably 120 to 250°C, more preferably 160 to 200°C, in consideration of the reaction rate and the inhibition of gelation. In addition, the reaction time is preferably 0.5 to 10 hours after the start of the distillation of the produced water.

[Polyimide Varnish] The polyimide varnish of the present invention is obtained by dissolving the polyimide resin of the present invention in an organic solvent. That is, the polyimide varnish of the present invention contains the polyimide resin of the present invention and an organic solvent, and the polyimide resin is dissolved in the organic solvent. The organic solvent is not particularly limited as long as it dissolves the polyimide resin, and it is preferable to use the above-mentioned compounds as the reaction solvent used in the production of the polyimide resin alone or in combination of two or more. The polyimide resin of the present invention has solvent solubility, so it can be made into a high-concentration varnish that is stable at room temperature. The polyimide varnish of the present invention preferably contains 5 to 40% by mass of the polyimide resin of the present invention, more preferably 10 to 30% by mass. The viscosity of the polyimide varnish is preferably 1~200Pa･s, more preferably 5~150Pa･s. In addition, the polyimide varnish of the present invention may also contain inorganic fillers, adhesion promoters, release agents, flame retardants, UV stabilizers, interface Activating agent, leveling agent, defoaming agent, optical brightener, crosslinking agent, polymerization initiator, sensitizer and other additives. The manufacturing method of the polyimide varnish of this invention is not specifically limited, A well-known method can be used.

[Polyimide film] The polyimide film of the present invention contains the polyimide resin of the present invention. Therefore, the polyimide film of the present invention is excellent in colorless transparency, optical isotropy, and laser peelability. The method for producing the polyimide film of the present invention is not particularly limited, and a known method can be used. For example, the method of removing an organic solvent after coating or shaping|molding the polyimide varnish of this invention into a thin film, etc. are mentioned.

The polyimide film of the present invention is excellent in colorless transparency, optical isotropy, and laser releasability, so it can be ideally used as various members such as color filters, flexible displays, semiconductor parts, and optical members. film used. In particular, the polyimide film of the present invention can be ideally used as a substrate for image display devices such as liquid crystal displays and OLED displays. [Example]

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these embodiments. The solid content concentration of the polyimide varnishes obtained in Examples and Comparative Examples and the physical properties of the polyimide films were measured by the methods shown below.

(1) Solid content concentration The solid content concentration of the polyimide varnish was measured by heating the sample at 320°C × 120min using a small electric furnace "MMF-1" manufactured by AS ONE Co., Ltd., and the mass of the sample before and after heating was determined. The difference is calculated. (2) Film thickness The film thickness was measured using a micrometer manufactured by Mitutoyo Co., Ltd. (3) Total light transmittance, yellow index (YI) The measurement was performed according to JIS K7361-1 using a color-turbidity simultaneous measuring device "COH400" manufactured by Nippon Denshoku Industries Co., Ltd. (4) Thickness retardation (Rth) The thickness retardation (Rth) was measured using an ellipsometry "M-220" manufactured by JASCO Corporation. The value of the thickness retardation was measured at a measurement wavelength of 590 nm. In addition, let the maximum refractive index of the in-plane refractive index of the polyimide film be nx, the minimum refractive index be ny, and let the refractive index in the thickness direction be nz, and the thickness of the film be d, Rth is represented by the following formula By. Rth={[(nx+ny)/2]-nz}×d (5) Light transmittance at wavelength 308nm The measurement was performed using an ultraviolet/visible/near-infrared spectrophotometer "UV-3100PC" manufactured by Shimadzu Corporation. (6) Water absorption Obtained according to JIS K7209. After drying the 50mm×50mm polyimide film at 50°C for 24 hours, return to room temperature in a desiccator, and measure the weight (W0) at 23°C and humidity 50±5%. Then, the film was immersed in distilled water at 23° C. for 24 hours, and the water on the surface was wiped off, and then the weight (W1) after 1 minute was measured. The water absorption rate was calculated according to the following formula. Water absorption (%)=[(W1-W0)/W0]×100

<Example 1> 9,9-bis(4-amino) was placed in a 500 mL 5-neck round-bottomed flask equipped with a half-moon stirring blade made of stainless steel, a nitrogen introduction tube, a Dean-Stark equipped with a cooling tube, a thermometer, and a glass end cap. 34.845 g (0.100 mol) of phenyl) fenugreek (manufactured by Tagoka Chemical Industry Co., Ltd.) and 83.018 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Co., Ltd.) were added at a temperature of 70°C in the system under a nitrogen atmosphere. , and stirred at 200 rpm to obtain a solution. To this solution, 1,2,4,5-cyclohexanetetracarboxylic dianhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd.) 11.209 g (0.050 mol), 9,9'-bis(3,4 -22.922 g (0.050 mol) of -dicarboxyphenyl) fluoride (manufactured by JFE Chemical Co., Ltd.), and 20.755 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Co., Ltd.), were charged as 5.060 g of triethylamine (manufactured by Kanto Chemical Co., Ltd.) and 0.561 g of triethylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd.) as amination catalysts were heated with a heating mantle, and the reaction system was heated for about 20 minutes. The internal temperature rose to 190°C. The distilled components were collected, and the internal temperature of the reaction system was maintained at 190° C. and refluxed for 5 hours while adjusting the rotational speed according to the increase in viscosity. Then, 158.54 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Co., Ltd.) was added, and the temperature in the reaction system was cooled to 120° C., and further stirred for about 3 hours to homogenize to obtain a solid content concentration of 20% by mass. of polyimide varnish. Then, the obtained polyimide varnish was coated on a glass plate, kept at 80° C. for 20 minutes on a hot plate, and then heated at 300° C. for 30 minutes in a nitrogen atmosphere in a hot air dryer to evaporate the solvent to obtain a thickness of 14μm thin film. The results are shown in Table 1.

<Example 2> The amount of 9,9-bis(4-aminophenyl) fluoride (manufactured by Tagoka Chemical Industry Co., Ltd.) was changed from 34.845 g (0.100 mol) to 17.423 g (0.050 mol), and bis(4 mol) was added. A polyimide varnish was prepared in the same manner as in Example 1, except that 12.415 g (0.050 mol) of -aminophenyl) bismuth (manufactured by Wakayama Seika Industry Co., Ltd.) was obtained to obtain a solid content concentration of 20 Mass % polyimide varnish. Using the obtained polyimide varnish, a thin film was produced in the same manner as in Example 1 to obtain a thin film having a thickness of 10 μm. The results are shown in Table 1.

<Example 3> Changed 12.415 g (0.050 mol) of bis(4-aminophenyl) bismuth (manufactured by Wakayama Seika Industry Co., Ltd.) to 2,2'-bis(trifluoromethyl)benzidine (Wakayama Seika Industry Co., Ltd.) A polyimide varnish was produced in the same manner as in Example 2, except for 16.012 g (0.050 mol) (manufactured by Co., Ltd.), and a polyimide varnish having a solid content concentration of 20 mass % was obtained. Using the obtained polyimide varnish, a film was produced by the same method as in Example 1, and a film with a thickness of 12 μm was obtained. The results are shown in Table 1.

<Example 4> The amount of 9,9-bis(4-aminophenyl) fluoride (manufactured by Tagoka Chemical Industry Co., Ltd.) was changed from 34.845 g (0.100 mol) to 30.629 g (0.08790 mol), and both terminal amines were added A polyimide varnish was prepared in the same manner as in Example 1, except that 16.214 g (0.01210 mol) of base-modified polysiloxane oil "X-22-9409" (manufactured by Shin-Etsu Chemical Co., Ltd.) , to obtain a polyimide varnish with a solid content concentration of 20% by mass. Using the obtained polyimide varnish, a thin film was produced in the same manner as in Example 1 to obtain a thin film having a thickness of 10 μm. The results are shown in Table 1.

<Example 5> The amount of 9,9-bis(4-aminophenyl) fluoride (manufactured by Tagoka Chemical Industry Co., Ltd.) was changed from 34.845 g (0.100 mol) to 15.450 g (0.04434 mol), and bis(4 mol) was added. -Aminophenyl) bismuth (manufactured by Wakayama Seika Industry Co., Ltd.) 11.010 g (0.04434 mol), both-terminal amino-modified polysiloxane oil "X-22-9409" (Shin-Etsu Chemical Industry Co., Ltd.) A polyimide varnish was produced by the same method as in Example 1, except that 15.169 g (0.01132 mol) produced by the company, and a polyimide varnish having a solid content concentration of 20 mass % was obtained. Using the obtained polyimide varnish, a film was produced by the same method as in Example 1, and a film with a thickness of 8 μm was obtained. The results are shown in Table 1.

<Example 6> The amount of 9,9-bis(4-aminophenyl) fluoride (manufactured by Tagaoka Chemical Industry Co., Ltd.) was changed from 15.450 g (0.04434 mol) to 15.360 g (0.04408 mol), bis(4-amine) 11.010 g (0.04434 mol) of phenyl) phenyl (Wakayama Seika Kogyo Co., Ltd.) was changed to 2,2'-bis(trifluoromethyl)benzidine (manufactured by Wakayama Seika Kogyo Co., Ltd.) 14.116g (0.04408mol), the amount of both-terminal amino-modified polysiloxane oil "X-22-9409" (manufactured by Shin-Etsu Chemical Co., Ltd.) was changed from 15.169g (0.01132mol) to 15.879g ( 0.01184 moles), except that a polyimide varnish was produced by the same method as in Example 5, and a polyimide varnish having a solid content concentration of 20 mass % was obtained. Using the obtained polyimide varnish, a film was produced by the same method as in Example 1, and a film with a thickness of 9 μm was obtained. The results are shown in Table 1.

<Example 7> The amount of 9,9-bis(4-aminophenyl) fluoride (manufactured by Tagoka Chemical Industry Co., Ltd.) was changed from 15.360 g (0.04408 mol) to 16.471 g (0.04727 mol), 2,2'- The amount of bis(trifluoromethyl)benzidine (manufactured by Wakayama Seika Industry Co., Ltd.) was changed from 14.116 g (0.04408 mol) to 15.138 g (0.04727 mol), and both-terminal amino group-modified polysiloxane oil It was produced by the same method as in Example 6, except that the amount of "X-22-9409" (manufactured by Shin-Etsu Chemical Co., Ltd.) was changed from 15.879 g (0.01184 mol) to 7.316 g (0.00546 mol). A polyimide varnish was obtained to obtain a polyimide varnish having a solid content concentration of 20% by mass. Using the obtained polyimide varnish, a thin film was produced in the same manner as in Example 1 to obtain a thin film having a thickness of 8 μm. The results are shown in Table 1.

<Comparative Example 1> The amount of 1,2,4,5-cyclohexanetetracarboxylic dianhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd.) was changed from 11.209 g (0.050 mol) to 22.417 g (0.100 mol) without adding A polymer was prepared in the same manner as in Example 1, except for 22.922 g (0.050 mol) of 9,9'-bis(3,4-dicarboxyphenyl) fluoride (manufactured by JFE Chemical Co., Ltd.). An imide varnish was obtained to obtain a polyimide varnish having a solid content concentration of 20% by mass. Using the obtained polyimide varnish, a film was produced in the same manner as in Example 1, and a film with a thickness of 11 μm was obtained. The results are shown in Table 2.

<Comparative Example 2> 34.845 g (0.100 mol) of 9,9-bis(4-aminophenyl) fluoride (manufactured by Tagoka Chemical Industry Co., Ltd.) was changed to 2,2'-bis(trifluoromethyl)benzidine (Wakayama A polyimide varnish was prepared in the same manner as in Comparative Example 1, except for 32.024 g (0.100 mol) of Seika Kogyo Co., Ltd., and a polyimide varnish having a solid content concentration of 20 mass % was obtained. Using the obtained polyimide varnish, a film was produced by the same method as in Example 1, and a film with a thickness of 9 μm was obtained. The results are shown in Table 2.

<Comparative Example 3> 22.922 g (0.050 mol) of 9,9'-bis(3,4-dicarboxyphenyl) fluoride (manufactured by JFE Chemical Co., Ltd.) was changed to 3,3',4,4'-biphenyl Tetracarboxylic dianhydride (s-BPDA) (manufactured by Mitsubishi Chemical Co., Ltd.) 14.710 g (0.050 moles), 9,9-bis(4-aminophenyl) fluoride (manufactured by Tagaoka Chemical Industry Co., Ltd.) ) was changed from 30.629 g (0.08790 mol) to 31.064 g (0.08915 mol), and the amount of both-terminal amino-modified polysiloxane oil "X-22-9409" (manufactured by Shin-Etsu Chemical Co., Ltd.) Except having changed from 16.214g (0.01210 mol) to 14.539 g (0.01085 mol), a polyimide varnish was produced by the same method as in Example 4, and a polyimide varnish having a solid content concentration of 20 mass % was obtained . Using the obtained polyimide varnish, a film was produced by the same method as in Example 1, and a film with a thickness of 15 μm was obtained. The results are shown in Table 2.

<Comparative Example 4> 22.922 g (0.050 mol) of 9,9'-bis(3,4-dicarboxyphenyl) fluoride (manufactured by JFE Chemical Co., Ltd.) was changed to 3,3',4,4'-biphenyl A polyimide varnish was prepared in the same manner as in Example 1, except for 14.710 g (0.050 mol) of tetracarboxylic dianhydride (s-BPDA) (manufactured by Mitsubishi Chemical Corporation), and the solid content concentration was obtained. 20% by mass of polyimide varnish. Using the obtained polyimide varnish, a film was produced by the same method as in Example 1, and a film with a thickness of 8 μm was obtained. The results are shown in Table 2.

【Table 1】

【Table 2】

The abbreviations in Tables 1 and 2 are as follows. HPMDA: 1,2,4,5-cyclohexanetetracarboxylic dianhydride (compound represented by formula (a-1)) BPAF: 9,9'-bis(3,4-dicarboxyphenyl)indianhydride (compound represented by formula (a-2)) BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride BAFL: 9,9-bis(4-aminophenyl) fluoride (compound represented by formula (b-1)) 4,4-DDS: bis(4-aminophenyl) bismuth (compound represented by formula (b-2-1)) TFMB: 2,2'-bis(trifluoromethyl)benzidine (compound represented by formula (b-2-2)) X-22-9409: Amino-modified polysiloxane oil at both ends (compound represented by formula (b-2-3))

As shown in Table 1, the polyimide films of Examples 1 to 7 were excellent in colorless transparency, optical isotropy, and laser peelability. In addition, the polyimide films of Examples 3 to 7 also had low water absorption. On the other hand, as shown in Table 2, the laser peelability of the polyimide film of Comparative Example 1 was significantly poor, and the optical isotropy and laser peelability of the polyimide film of Comparative Example 2 were significantly poor , the colorless transparency of the polyimide films of Comparative Examples 3 and 4 is remarkably poor.

Claims (7)

A polyimide resin containing a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from a diamine; the structural unit A contains a structural unit (A-1) derived from a compound represented by the following formula (a-1) ), and the structural unit (A-2) derived from the compound represented by the following formula (a-2); the structural unit B contains the structural unit (B-1) derived from the compound represented by the following formula (b-1); the structural unit B The ratio of the constituent unit (B-1) in it is 30~100 mol%;

In formula (b-1), R is each independently a hydrogen atom, a fluorine atom or a methyl group. For example, the polyimide resin of claim 1, wherein the ratio of the structural unit (A-1) in the structural unit A is 10-90 mol%, and the structural unit (A-2) in the structural unit A is 10-90 mol%. The ratio of 10~90 mol%. According to the polyimide resin of claim 1 or 2, the structural unit B further contains a structural unit (B-2), and the structural unit (B-2) is selected from the following formula (b-2- 1) The constituent unit (B-2-1) of the compound represented by the following formula (b-2-2), the constituent unit (B-2-2) derived from the compound represented by the following formula (b-2-2), and the constituent unit derived from the following formula (b-2-3) At least one of the group consisting of the structural unit (B-2-3) of the compound represented by ); [Chem. 2]

In formula (b-2-3), R ₁ to R ₄ are each independently a monovalent aliphatic group or a monovalent aromatic group, and Z ₁ and Z ₂ are each independently a divalent aliphatic group or a divalent aromatic group base, r is a positive integer. Such as the polyimide resin of claim 3, wherein the ratio of the structural unit (B-1) in the structural unit B is 30-95 mol%, and the structural unit (B-2) in the structural unit B The ratio of 5 to 70 mol%. Such as the polyimide resin of claim 1 or 2, wherein, R represents a hydrogen atom. A polyimide varnish is prepared by dissolving the polyimide resin according to any one of items 1 to 5 of the patent application scope in an organic solvent. A polyimide film, comprising the polyimide resin according to any one of items 1 to 5 of the patent application scope.