TW202328309A - Coating composition, preparation methods of the coating composition and polyimide resin wherein the coating composition includes polyamic acid and a solvent - Google Patents

Abstract

The object of the present invention is to provide a coating composition capable of forming a polyimide resin having less coloration and excellent mechanical properties, a method for producing the coating composition, and a method for producing a polyimide resin using the coating composition. The solution of the present invention includes a coating composition of polyamic acid (A) and a solvent (S), wherein the polyamic acid (A) includes polymers of alicyclic tetracarboxylic dianhydride (A1-1) with a specific structure, a small amount of alicyclic tetracarboxylic dianhydride (A1-2) other than the alicyclic tetracarboxylic dianhydride (A1-1) and aromatic diamine compound (A2).

Description

Coating composition, manufacturing method of coating composition, and manufacturing method of polyimide resin

The present invention relates to a coating composition, a method for producing the coating composition, and a method for producing a polyimide resin using the coating composition.

Polyimide resin is widely used in electrical and electronic components such as electronic substrates such as various components or multilayer wiring boards due to its excellent heat resistance, mechanical strength, insulation, and low dielectric constant. Used as insulating or protective material.

Generally, the polyimide resin is formed by heat-treating polyamic acid obtained by polymerizing tetracarboxylic dianhydride components and diamine components in a polar organic solvent. There is also such a background. Most polyimide products used in electronic materials are supplied as solutions of polyimide precursors such as polyamic acid. Specifically, in the manufacture of electrical and electronic parts, the solution of the polyimide precursor is supplied by coating or injection at the point where the insulating material or protective material is formed, and then the solution of the polyimide precursor is heat-treated , and form an insulating material or a protective material.

Technological development of such polyimide resins has been earnestly studied, and various resin compositions including polyamic acid and the like have been disclosed (for example, refer to Patent Document 1 and the like). [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2018-58918

[Problem to be solved by the invention]

In polyimide resins, especially polyimide films, depending on the application, less coloring or excellent mechanical properties such as elongation at break may be desired. However, when a polyimide resin is produced using the resin composition described in Patent Document 1 and the like as a paint composition, it is difficult to form a polyimide resin having both less coloring and excellent mechanical properties.

The present invention was made in view of the above-mentioned problems to provide a coating composition capable of forming a polyimide resin having less coloration and excellent mechanical properties, a method for producing the coating composition, and a coating composition using the coating composition The production method of the polyimide resin is the purpose. [Means to solve the problem]

The present inventors found that in the coating composition comprising polyamic acid (A) and solvent (S), by combining alicyclic tetracarboxylic dianhydride (A1-1) with a specific structure and a small amount of lipid Polymers of alicyclic tetracarboxylic dianhydrides (A1-2) other than cyclic tetracarboxylic dianhydrides (A1-1) and aromatic diamine compounds (A2) are used as polyamic acid (A) , can solve the above-mentioned problems, and finally complete the present invention. More specifically, the present invention provides the following.

The first aspect of the present invention is a coating composition characterized by comprising polyamic acid (A) and solvent (S), polyamic acid (A) is tetracarboxylic dianhydride (A1) and aromatic A polymer of diamine compound (A2), tetracarboxylic dianhydride (A1) is alicyclic tetracarboxylic dianhydride (A1-1) and alicyclic tetracarboxylic dianhydride (A1-1) of a compound represented by the following formula (a2) Composed of other alicyclic tetracarboxylic dianhydrides (A1-2) other than acid dianhydrides (A1-1), (In formula (a2), R ^a11 , R ^a12 and R ^a13 are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and a fluorine atom, and a is 0 or more an integer below 12). The ratio of the mass of other alicyclic tetracarboxylic dianhydride (A1-2) to the number of moles of tetracarboxylic dianhydride (A1) is 0.1 mol % or more and 6 mol % or less.

The second aspect of the present invention is a method for producing a paint composition, which includes: polymerizing tetracarboxylic dianhydride (A1) and aromatic diamine compound (A2) in a solvent (S), and making polyamide Acid (A) is generated, or tetracarboxylic dianhydride (A1) and aromatic diamine compound (A2) are polymerized to generate polyamic acid (A), and the isolated polyamic acid (A) A method for producing a paint composition mixed with a solvent (S), characterized in that the tetracarboxylic dianhydride (A1) is an alicyclic tetracarboxylic dianhydride (A1-1) of a compound represented only by the following formula (a2) ), and other alicyclic tetracarboxylic dianhydrides (A1-2) other than alicyclic tetracarboxylic dianhydrides (A1-1), (In formula (a2), R ^a11 , R ^a12 and R ^a13 are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and a fluorine atom, and a is 0 or more an integer below 12). The ratio of the mass of said other alicyclic tetracarboxylic dianhydride (A2-2) to the number of moles of tetracarboxylic dianhydride (A2) is 0.1 mol% or more and 6 mol% or less.

The 3rd aspect of the present invention is a kind of manufacturing method of polyimide resin, and it is to comprise: The forming step of forming the coating composition of the first aspect, and The imidization step of heating the formed coating composition to imidize it. [Invention effect]

According to the present invention, it is possible to provide a coating composition capable of forming a polyimide resin having less coloration and excellent mechanical properties, a method for producing the coating composition, and a polyimide resin using the coating composition. Manufacturing method.

≪Paint composition≫

The coating composition includes polyamic acid (A), and a solvent (S). The coating composition is used in the formation of polyimide resin.

Hereinafter, the essential or optional components of the paint composition will be described.

＜Polyamide (A)＞ The coating composition contains polyamic acid (A). Polyamic acid (A) is a precursor polymer of polyimide resin produced when the coating composition is cured.

Polyamic acid (A) is a polymer of tetracarboxylic dianhydride (A1) and aromatic diamine compound (A2). Tetracarboxylic dianhydride (A1) is composed only of alicyclic tetracarboxylic dianhydride (A1-1) and other alicyclic tetracarboxylic dianhydride (A1-1) A1-2) Composition. The ratio of the mass of alicyclic tetracarboxylic dianhydride (A1-2) to the number of moles of tetracarboxylic dianhydride (A1) is 0.1 mol % or more and 6 mol % or less. By using this polyamic acid (A) and using a coating composition, the polyimide resin which has little coloring and excellent mechanical characteristics can be formed. As mechanical properties, generally, they are elongation at break, coefficient of thermal expansion (CTE), and the like.

Hereinafter, the production method of tetracarboxylic dianhydride (A1), aromatic diamine compound (A2), and polyamic acid (A) used in the production of polyamic acid (A) will be described below. .

[Tetracarboxylic dianhydride (A1)] Tetracarboxylic dianhydride (A1) is composed only of alicyclic tetracarboxylic dianhydride (A1-1) and other alicyclic tetracarboxylic dianhydride (A1-1) A1-2) Composition. The ratio of the mass of alicyclic tetracarboxylic dianhydride (A1-2) to the number of moles of tetracarboxylic dianhydride (A1) is 0.1 mol % or more and 6 mol % or less. The ratio of the mass of alicyclic tetracarboxylic dianhydride (A1-2) to the number of moles of tetracarboxylic dianhydride (A1) is preferably 0.2 mol % or more and 5.5 mol % or less, more preferably 0.5 mol % More than 5 mole% and less than 5 mole%.

(alicyclic tetracarboxylic dianhydride (A1-1)) Alicyclic tetracarboxylic dianhydride (A1-1) is a compound represented by following formula (a2). When a compound represented by the following formula (a2) is used, it tends to be easy to obtain a polyimide resin excellent in transparency. Furthermore, a in the formula (a2) is preferably 5 or less, more preferably 3 or less, from the viewpoint of ease of purification of the raw material compound. Moreover, since the chemical stability of the raw material compound is excellent, a is preferably 1 or more, more preferably 2 or more. a in the formula (a2) is particularly preferably 2 or 3.

(In formula (a2), R ^a11 , R ^a12 and R ^a13 are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and a fluorine atom, and a is 0 or more an integer below 12).

The alkyl group that can be selected as R ^a11 in formula (a2) is an alkyl group having 1 to 5 carbon atoms. The number of carbon atoms in the alkyl group is still more preferably from 1 to 4, particularly preferably from 1 to 3. R ^a11 is an alkyl group, and the alkyl group may be linear or branched.

As R ^a11 in the formula (a2), it is more preferable to be a hydrogen atom, a methyl group, an ethyl group, an n-propyl group or an iso The propyl group is particularly preferably a hydrogen atom or a methyl group. The plurality of R ^a11 in the formula (a2) are preferably the same group because the purification of the tetracarboxylic dianhydride represented by the formula (a2) is easy.

a in the formula (a2) represents an integer of 0 to 12. When the value of a exceeds 12, purification of tetracarboxylic dianhydride which gives a tetravalent organic group represented by formula (a2) becomes difficult. The upper limit of a is preferably 5, more preferably 3, from the viewpoint of easy purification of tetracarboxylic dianhydride represented by formula (a2). The lower limit of a is preferably 1, more preferably 2 from the viewpoint of the chemical stability of tetracarboxylic dianhydride represented by formula (a2). a in the formula (a2) is particularly preferably 2 or 3.

The alkyl group having 1 to 5 carbon atoms that can be selected as R ^a12 and R ^a13 in formula (a2) is the same as the alkyl group having 1 to 5 carbon atoms that can be selected as R ^a11 . R ^a12 and R ^a13 are preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, particularly preferably a hydrogen atom or a methyl group, from the viewpoint of ease of purification of the tetracarboxylic dianhydride represented by the formula (a2). .

As the tetracarboxylic dianhydride represented by formula (a2), for example, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2"-norbornane-5,5",6 ,6"-tetracarboxylic dianhydride (alias "norbornane-2-spirocycle-2'-cyclopentanone-5'-spirocycle-2"-norbornane-5,5",6,6" -tetracarboxylic dianhydride"), methylnorbornane-2-spiro-α-cyclopentanone-α'-spiro-2"-(methylnorbornane)-5,5",6, 6"-tetracarboxylic dianhydride, norbornane-2-spiro-α-cyclohexanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid Dianhydride (alias "norbornane-2-spiro-2'-cyclohexanone-6'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic dianhydride" ), Methylnorbornane-2-spiro-α-cyclohexanone-α'-spiro-2”-(methylnorbornane)-5,5”,6,6”-tetracarboxylic dicarboxylic acid Anhydride, norbornane-2-spiro-α-cyclopropanone-α'-spiro-2”-norbornane-5,5”,6,6”-tetracarboxylic dianhydride, norbornane-2 -spiro-α-cyclobutanone-α'-spiro-2”-norbornane-5,5”,6,6”-tetracarboxylic dianhydride, norbornane-2-spiro-α- Cycloheptanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic dianhydride, norbornane-2-spiro-α-cyclooctanone-α' -Spiro-2"-Norbornane-5,5",6,6"-tetracarboxylic dianhydride, norbornane-2-spiro-α-cyclononanone-α'-spiro-2" -Norbornane-5,5",6,6"-tetracarboxylic dianhydride, norbornane-2-spiro-α-cyclodecanone-α'-spiro-2"-norbornane-5 ,5",6,6"-Tetracarboxylic dianhydride, norbornane-2-spiro-α-cycloundecone-α'-spiro-2"-norbornane-5,5", 6,6"-tetracarboxylic dianhydride, norbornane-2-spiro-α-cyclododecanone-α'-spiro-2"-norbornane-5,5",6,6" -Tetracarboxylic dianhydride, norbornane-2-spiro-α-cyclotridecanone-α'-spiro-2”-norbornane-5,5”,6,6”-tetracarboxylic acid Dianhydride, norbornane-2-spiro-α-cyclotetradecanone-α'-spiro-2”-norbornane-5,5”,6,6”-tetracarboxylic dianhydride, norbornane Bornane-2-spiro-α-cyclopentadecanone-α'-spiro-2”-norbornane-5,5”,6,6”-tetracarboxylic dianhydride, norbornane-2 -Spiro-α-(methylcyclopentanone)-α'-spiro-2”-norbornane-5,5”,6,6”-tetracarboxylic dianhydride, norbornane-2-spiro Cyclo-α-(methylcyclohexanone)-α'-spiro-2”-norbornane-5,5”,6,6”-tetracarboxylic dianhydride, etc.

Also, as the tetracarboxylic dianhydride represented by the formula (a2), it is preferable to contain At least one of compound (A2-1) represented by the following formula (a2-1) and compound (A2-2) represented by the following formula (a2-2), and compound (A2-1) and compound ( A2-2) The total amount is more than 30 mol% of tetracarboxylic dianhydride, (In formula (a2-1), R ^a11 , R ^a12 , R ^a13 , and a are synonymous with R ^a11 , R ^a12 , R ^a13 , and a in formula (a2). (In formula (a2-2), R ^a11 , R ^a12 , R ^a13 , and a are synonymous with R ^a11 , R ^a12 , R ^a13 , and a in formula (a2).

The compound (A2-1) represented by the formula (a2-1) has two norbornyl groups trans-configured, and with respect to each of the two norbornyl groups, the carbonyl group of the cycloalkanone is end-stereo-configured An isomer of tetracarboxylic dianhydride represented by formula (a2). The compound (A2-2) represented by the formula (a2-2) has two norbornyl groups in cis configuration, and relative to each of the two norbornyl groups, the carbonyl group of the cycloalkanone is end-stereo-configured An isomer of tetracarboxylic dianhydride represented by formula (a2). Also, the method for producing tetracarboxylic dianhydride containing such isomers at the above ratio is not particularly limited, and known methods can be appropriately used, for example, the method described in International Publication No. 2014/034760 can be appropriately used wait.

(Alicyclic tetracarboxylic dianhydride (A1-2)) Alicyclic tetracarboxylic dianhydride (A1-2) is alicyclic tetracarboxylic dianhydride other than alicyclic tetracarboxylic dianhydride (A1-1) Acid dianhydride. As a suitable example of alicyclic tetracarboxylic dianhydride (A1-2), the compound represented by following formula (a1-1) is mentioned. As mentioned above, the compound represented by following formula (a1-1) does not correspond to alicyclic tetracarboxylic dianhydride (A1-1). Alicyclic tetracarboxylic dianhydride (A1-2) may be used individually by 1 type, and may use it in combination of 2 or more types. (In the formula (a1-1), A ¹ is a tetravalent organic group with 4 to 50 carbon atoms including an alicyclic ring that does not contain an aromatic group. In the formula (a1-1), two carboxylic acid anhydride groups bond attached to the alicyclic ring).

In the formula (a1-1), A ¹ is a tetravalent organic group having 4 to 50 carbon atoms including an alicyclic ring not containing an aromatic group. A ¹ in formula (a1-1) may have one or plural substituents in addition to two carboxylic acid anhydride groups. Suitable examples of substituents are preferably fluorine atoms, alkyl groups having 1 to 6 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, fluorinated alkyl groups having 1 to 6 carbon atoms, A fluorinated alkoxy group having 1 to 6 carbon atoms. Moreover, the compound represented by formula (a1-1) may contain a carboxyl group and a carboxylate group other than an acid anhydride group. When the substituent is a fluorinated alkyl group or a fluorinated alkoxy group, it is preferably a perfluoroalkyl group or a perfluoroalkoxy group.

Alicyclic tetracarboxylic dianhydride (A1-2) is a compound which has two carboxylic acid anhydride groups bonded to an alicyclic ring and does not contain an aromatic group. The alicyclic tetracarboxylic dianhydride may have a linear or branched chain aliphatic group. The alicyclic and chain aliphatic groups which the alicyclic tetracarboxylic dianhydride (A1-2) has may contain a halogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom other than a carbon atom and a hydrogen atom. Such as oxygen atom, nitrogen atom or sulfur atom, as selected from nitrogen-containing heterocyclic group, -CONH-, -NH-, -N=N-, -CH=N-, -COO-, -O-, -CO- The groups in , -SO-, -SO ₂ -, -S- and -SS- may be included in alicyclic and chain aliphatic groups.

The alicyclic ring included in the alicyclic tetracarboxylic dianhydride (A1-2) may be monocyclic or polycyclic. Examples of the polycyclic alicyclic structure include bridged alicyclic structures such as bicyclo[2.2.1]heptane, and the like. For example, bridged alicyclic structures can be condensed with other bridged alicyclic structures and/or non-bridged alicyclic structures, and bridged alicyclic structures can also be condensed with other bridged alicyclic structures and/or non-bridged alicyclic structures. Screw key to connect. By using the alicyclic tetracarboxylic dianhydride (A1-2) and using the coating composition, a polyimide resin excellent in transparency was obtained.

Specific examples of alicyclic tetracarboxylic dianhydride (A1-2) include 1,2,4,5-cyclohexanetetracarboxylic dianhydride, bicyclo[2.2.2]octane-2 ,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 5-(2,5-two-side oxygen yltetrahydrofuran-3-yl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 4-(2,5-dipentoxytetrahydrofuran-3-yl)-tetrahydronaphthalene-1 ,2-dicarboxylic anhydride, tetrahydrofuran-2,3,4,5-tetracarboxylic dianhydride, 1,2,3,4-cyclopentane tetracarboxylic dianhydride, 1,2,3,4-cyclobutane Alkane tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride, and 1,4-dimethyl-1,2,3,4-cyclobutane Butane tetracarboxylic dianhydride, etc.

As alicyclic tetracarboxylic dianhydride (A1-2), the compound represented by following formula (a2-1) or following formula (a2-2) is also preferable. (In formula (a2-1), R ^a21 , R ^a22 , R ^a23 and R ^a24 are each independently a hydrogen atom, an alkyl group with 1 to 5 carbon atoms, or an alkenyl group with 2 to 5 carbon atoms, and R ^a21 Or R ^a22 , and R ^a23 or R ^a24 can be bonded to each other to form methylene, ethylene, propane-2,2-diyl, ethylene-1,2-diyl, in formula (a2-2), R ^a25 , R ^a26 , R ^a27 , R ^a28 , R ^a29 , R ^a30 , R ^a31 and R ^a32 are each independently a hydrogen atom, an alkyl group with 1 to 5 carbon atoms, or an alkenyl group with 2 to 5 carbon atoms , R ^a25 or R ^a26 , and R ^a27 or R ^a28 can be bonded to each other to form methylene, ethylene, propane-2,2-diyl, ethylene-1,2-diyl, R ^a29 or R ^a30 , and R ^a31 or R ^a32 can be bonded to each other to form methylene, ethylene, propane-2,2-diyl, ethylene-1,2-diyl).

In the formula (a2-1), the alkyl or alkenyl group in R ^a21 , R ^a22 , R ^a23 and R ^a24 may be linear or branched. Suitable examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl and n-pentyl. Suitable examples of alkenyl include vinyl, allyl, 3-butenyl and 4-pentenyl.

In formula (a2-2), the alkyl or alkenyl groups of R ^a25 , R ^a26 , R ^a27 , R ^a28 , R ^a29 , R ^a30 , R ^a31 and R ^a32 may be linear or branched. branch chain. Suitable examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl and n-pentyl. Suitable examples of alkenyl include vinyl, allyl, 3-butenyl and 4-pentenyl.

Suitable examples of the compound represented by formula (a2-1) or formula (a2-2) include the following compounds.

[Aromatic diamine compound (A2)] As the aromatic diamine compound (A2), a diamine compound having an aromatic group that has been conventionally used in the production of polyimide resins can be used without particular limitation. Here, let the diamine compound whose two amine groups are all bonded to an aromatic group be an aromatic diamine compound (A2).

As an aromatic diamine compound (A2), the compound represented by following formula (a3-1) can be used normally. The aromatic diamine compound (A2) may be used individually by 1 type, and may use it in combination of 2 or more types. (In the formula (a3-1), A ² represents a divalent organic group including an aromatic group. Both of the two amine groups in the formula (a3-1) are bonded to the aromatic group).

In the formula (a3-1), A ² is a divalent organic group including an aromatic group. The organic group as ^A2 may have one or more substituents in addition to the two amino groups in the formula (a3-1). Suitable examples of substituents are preferably fluorine atoms, alkyl groups having 1 to 6 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, fluorinated alkyl groups having 1 to 6 carbon atoms, A fluorinated alkoxy group or hydroxyl group having 1 to 6 carbon atoms. When the substituent is a fluorinated alkyl group or a fluorinated alkoxy group, it is preferably a perfluoroalkyl group or a perfluoroalkoxy group.

In formula (a3-1), the lower limit of the number of carbon atoms in the organic group of ^A2 is preferably 6. The upper limit is preferably 50, more preferably 30.

As the organic group of ^A2 , it can also be an aromatic group itself, or two or more aromatic groups through aliphatic hydrocarbon groups and halogenated aliphatic hydrocarbon groups, or heteroatoms including oxygen atoms, sulfur atoms, nitrogen atoms, etc. The bond of bond and the base of bond. Bonds including heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms included in ^A2 include -CONH-, -NH-, -N=N-, -CH=N-, -COO-, - O-, -CO-, -SO-, -SO ₂ -, -S- and -SS-, etc., preferably -O-, -CO-, -SO-, -SO ₂ -, -S- and - SS-.

The aromatic ring bonded to the amine group in ^A2 is preferably a benzene ring. When the ring bonded to the amino group in ^A2 is a condensed ring containing two or more rings, it is preferable that the ring bonded to the amino group in the condensed ring is a benzene ring. In addition, the aromatic ring included in ^A2 may be an aromatic heterocyclic ring.

When ^A2 is an organic group containing an aromatic ring, it is preferable that the aromatic diamine compound (A2) has the following formulas (21) to ( 24) At least one of the compounds represented. (In formulas (21) to (24), R ¹¹¹ represents a group consisting of a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group with 1 to 4 carbon atoms, and a halogenated alkyl group with 1 to 4 carbon atoms. One of the groups. In formula (24), Q represents 9,9'- fenylene, or is selected from the formula: -C ₆ H ₄ -, -CONH-C ₆ H ₄ -NHCO-, -NHCO -C ₆ H ₄ -CONH-, -OC ₆ H ₄ -CO-C ₆ H ₄ -O-, -OCO-C ₆ H ₄ -COO-, -OCO-C ₆ H ₄ -C ₆ H ₄ -COO -, -OCO-, -O-, -S-, -CO-, -CONH-, -SO ₂ -, -C(CF ₃ ) ₂ -, -C(CH ₃ ) ₂ -, -CH ₂ -, -OC ₆ H ₄ -C(CH ₃ ) ₂ -C ₆ H ₄ -O-, -OC ₆ H ₄ -C(CF ₃ ) ₂ -C ₆ H ₄ -O-, -OC ₆ H ₄ -SO ₂ -C ₆ H ₄ -O-, -C(CH ₃ ) ₂ -C ₆ H ₄ -C(CH ₃ ) ₂ -, -OC ₁₀ H ₆ -O-, -OC ₆ H ₄ -C ₆ H ₄ - One of the groups represented by O- and -OC ₆ H ₄ -O-. In the example of Q, -C ₆ H ₄ - is a phenylene group, preferably m-phenylene group and p - Phenylylene, more preferably p-phenylene. Also, -C ₁₀ H ₆ - is naphthalene diyl, preferably naphthalene-1,2-diyl, naphthalene-1,4-diyl, naphthalene- 2,3-diyl, naphthalene-2,6-diyl and naphthalene-2,7-diyl, more preferably naphthalene-1,4-diyl and naphthalene-2,6-diyl).

R ¹¹¹ in the formulas (21) to (24) is more preferably a hydrogen atom, a hydroxyl group, a fluorine atom, a methyl group, an ethyl group or a trifluoro A methyl group is particularly preferably a hydrogen atom, a hydroxyl group or a trifluoromethyl group.

As Q in the formula (24), from the viewpoint of the heat resistance of the polyimide resin to be formed, 9,9'-berylene, -OC ₆ H ₄ -O-, -C( CF ₃ ) ₂ -, -O-, -C(CH ₃ ) ₂ -, -CH ₂ - or -OC ₆ H ₄ -C(CH ₃ ) ₂ -C ₆ H ₄ -O-, -CONH-, more Preferably it is -CONH-, -OC ₆ H ₄ -O-, -C(CF ₃ ) ₂ - or -O-, particularly preferably -CONH-.

As the aromatic diamine compound represented by formula (a3-1), the compounds shown below can be suitably used. That is, examples of the aromatic diamine compound (A2) include p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 4,4'-diaminobiphenyl, 4, 4'-Diamino-2,2'-bis(trifluoromethyl)biphenyl, 3,3'-diaminodiphenyl, 4,4'-diaminodiphenyl, 4 ,4'-Diaminodiphenyl sulfide, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminobenzanilide, 3,3'-diaminobenzaniline, 1,4-bis(4-amine phenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)benzene Phenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]pyridine, bis[4-(3-aminophenoxy)phenyl]pyridine, 2,2-bis[ 4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 9,9-bis(4-amino Phenyl) fluorene, 9,9-bis(4-amino-3-methylphenyl) fluorene and 4,4'-[1,4-phenylene bis(1-methylethane-1,1 -diyl)] diphenylamine and the like. Among these, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, and 4,4'-diaminodiphenyl ether are preferable in terms of price and availability. and 4,4'-diaminobenzamide aniline.

The aromatic diamine compound (A2) is also preferably a compound represented by the following formula (25). (In formula (25), Ar ¹ and Ar ² are each independently an aromatic hydrocarbon group having 6 to 18 carbon atoms, and R ¹¹² is a hydrogen atom or a monovalent organic group).

Specific examples of the aromatic diamine compound (A2) represented by the formula (25) include 2,4-bis(4-aminoanilino)-1,3,5-trisalpine, 2,4-bis( 4-aminoanilino)-6-methyl-1,3,5-trimethanone, 2,4-bis(4-aminoanilino)-6-ethyl-1,3,5-trimethanone, 2,4-bis(4-aminoanilino)-6-phenyl-1,3,5-trimethanone, 2,4-bis(4-aminoanilino)-6-amino-1,3 ,5-Trisalpine, 2,4-bis(4-aminoanilino)-6-methylamino-1,3,5-trithiol, 2,4-bis(4-aminoanilino)- 6-Dimethylamino-1,3,5-trimethanol, 2,4-bis(4-aminoanilino)-6-ethylamino-1,3,5-trimethanol, 2,4 -Bis(4-aminoanilino)-6-diethylamino-1,3,5-trimethanone, 2,4-bis(4-aminoanilino)-6-anilino-1,3 , 5-three 𠯤, and 2,4-bis(4-aminoanilino)-6-diphenylamino-1,3,5-three 𠯤, etc. Among these, 2,4-bis(4-aminoanilino)-6-amino-1,3,5-trimethanone, 2,4-bis(4-aminoanilino)-6 -Methylamino-1,3,5-tri-methanol, 2,4-bis(4-aminoanilino)-6-ethylamino-1,3,5-tri-methanol, and 2,4- Bis(4-aminoanilino)-6-anilino-1,3,5-trisulfone, more preferably 2,4-bis(4-aminoanilino)-6-anilino-1,3, 5- Three 𠯤.

[Manufacturing method of polyamide acid (A)] Polyamic acid (A) is obtained by, for example, polymerizing tetracarboxylic dianhydride (A1) and aromatic diamine compound (A2) in an organic solvent. The usage-amount of tetracarboxylic dianhydride (A1) and aromatic diamine compound (A2) at the time of synthesizing polyamic acid (A) is not specifically limited. Relative to 1 mole of tetracarboxylic dianhydride (A1), it is preferable to use 0.50 mole to 1.50 mole of aromatic diamine compound (A2), more preferably to use 0.60 mole to 1.30 mole, especially preferred In order to use 0.70 mol or more and 1.20 mol or less. The weight average molecular weight of the obtained polyamic acid (A) should just be set suitably according to the use. The weight average molecular weight is, for example, 5,000 or more, preferably 7,500 or more, more preferably 10,000 or more. On the other hand, the weight average molecular weight of the obtained polyamic acid (A) is, for example, 100,000 or less, preferably 80,000 or less, more preferably 75,000 or less. This weight average molecular weight may be set to the above-mentioned value by adjusting the blending amount of tetracarboxylic dianhydride (A1) and aromatic diamine compound (A2), or reaction conditions such as solvent or reaction temperature.

The reaction of tetracarboxylic dianhydride (A1) and aromatic diamine compound (A2) is usually carried out in an organic solvent. If the organic solvent used for the reaction of tetracarboxylic dianhydride (A1) and diamine compound (A2) is soluble in tetracarboxylic dianhydride (A1) and aromatic diamine compound (A2), it will not react with tetracarboxylic dianhydride (A1) The organic solvent for the reaction between the acid dianhydride (A1) and the aromatic diamine compound (A2) is not particularly limited. An organic solvent can be used individually or in mixture of 2 or more types.

Examples of the organic solvent used for the reaction between the tetracarboxylic dianhydride (A1) and the aromatic diamine compound (A2) include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylformamide, N,N-diethylformamide, N-methylcaprolactam, and N,N,N', Nitrogen-containing polar solvents such as N'-tetramethylurea; dimethylsulfoxide; acetonitrile; ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane, and tetrahydrofuran.

Among these organic solvents, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N- Diethylacetamide, N,N-dimethylformamide, N,N-diethylformamide, N-methylcaprolactam and N,N,N',N'-tetramethyl Nitrogen-containing polar solvents such as urea.

The temperature at the time of making tetracarboxylic dianhydride (A1) and an aromatic diamine compound (A2) react is not specifically limited as long as reaction progresses favorably. Generally speaking, the reaction temperature between tetracarboxylic dianhydride (A1) and aromatic diamine compound (A2) is preferably from -5°C to 150°C, more preferably from 0°C to 120°C, especially preferably Above 0°C and below 70°C. The time for reacting the tetracarboxylic dianhydride (A1) and the aromatic diamine compound (A2) varies depending on the reaction temperature, but generally, it is preferably from 1 hour to 50 hours, and more preferably from 1 hour to 50 hours. More than 2 hours and less than 40 hours, especially preferably more than 5 hours and less than 30 hours.

By the method explained above, the solution containing polyamide acid (A) was obtained. The solution containing polyamic acid (A) obtained as described above can be directly used as a coating composition, or can also be used in the preparation of a coating composition. The solution containing polyamic acid (A) obtained as described above is under reduced pressure, and at a low temperature that does not produce the degree of transformation of the polyimide resin of polyamic acid (A), it is also possible to obtain the solution from polyamic acid (A). The paste or solid of the polyamic acid (A) obtained by removing at least a part of the solvent from the solution of the amide acid (A) is used in the preparation of a paint composition.

The content of the polyamic acid (A) in the paint composition can be appropriately determined in consideration of the coatability of the paint composition or the solubility to the solvent (S) of the polyamic acid (A). Generally speaking, the content of the polyamic acid (A) in the coating composition is preferably not less than 5 mass % and not more than 45 mass %, more preferably not less than 7 mass % and not more than 40 mass %, relative to the mass of the coating composition, More preferably, it is 10 mass % or more and 30 mass % or less.

＜Solvent (S)＞ The paint composition contains a solvent (S). The paint composition may be a paste containing solids or a solution, but is preferably a solution. A solvent (S) can be used individually or in mixture of 2 or more types. The type of solvent (S) is not particularly limited within the range that does not hinder the purpose of the present invention, and examples thereof include water, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monopropyl ether, Glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, Ethylene glycol monopropyl ether, and glycol monoethers such as diethylene glycol monophenyl ether; ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, propylene glycol di Glycol diethers such as methyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol dipropyl ether; Ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl Ether acetate, diethylene glycol monomethyl ether acetate, and glycol monoacetate such as diethylene glycol monoethyl ether acetate; diethylene glycol monopropyl ether acetate, Diethylene glycol monobutyl ether acetate, diethylene glycol monophenyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate , 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 2-methyl-3-methoxybutyl acetate, 3-Methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl Acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2- Methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, and 4-methoxypentyl acetate Monoether monoacetate of diols such as 4-methoxypentyl acetate; acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, ethyl isobutyl Ketones such as ketone and cyclohexanone; methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, 2-hydroxy -2-methyl, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, ethyl-3-propoxy Propionate, Propyl-3-methoxypropionate, Isopropyl-3-methoxypropionate, Ethoxyacetate, Ethyloxyacetate, 2-Hydroxy-3-methyl Methyl butyrate, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isopentyl acetate, methyl carbonate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate ester, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate and Esters such as γ-butyrolactone; ethers such as diethyl ether, dipropyl ether, dibutyl ether, dihexyl ether, benzyl methyl ether, benzyl ethyl ether and tetrahydrofuran; benzene, toluene Aromatics such as , xylene, ethylbenzene, cresol and chlorobenzene; Aliphatic alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, n-hexanol and cyclohexanol Glycols such as polyethylene glycol, ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; glycerin; etc. Moreover, the solvent used for the reaction of the said tetracarboxylic dianhydride (A1) and an aromatic diamine compound (A2) can also be used suitably as a solvent (S).

The solvent (S) may contain a nitrogen-containing compound represented by the following formula (S1). (In formula (S1), R ^S1 and R ^S2 are independently an alkyl group with 1 to 3 carbon atoms, and R ^S3 is a hydrogen atom or the following formula (S1-1) or the following formula (S1-2) base of representation, R ^S4 is a hydrogen atom or a hydroxyl group, R ^S5 and R ^S6 are each independently a hydrogen atom or an alkyl group with 1 to 3 carbon atoms, and R ^S7 and R ^S8 are each independently a hydrogen atom or an alkane with 1 to 3 carbon atoms group, when R ^S3 is a group represented by formula (S1-1), R ^S2 and R ^S3 may be bonded to each other to form a ring).

Among the nitrogen-containing compounds represented by formula (S1), specific examples of when R ^S3 is a hydrogen atom or a group represented by formula (S1-1) include N, N-dimethylformamide, N, N-di Methylacetamide, N,N,2-trimethylpropionamide, N-ethyl,N,2-dimethylpropionamide, N,N-diethyl-2-methylpropionamide , N,N,2-trimethyl-2-hydroxypropionamide, N-ethyl-N,2-dimethyl-2-hydroxypropionamide and N,N-diethyl-2-hydroxy- 2-methylacrylamide, etc.

Among the nitrogen-containing compounds represented by formula (S1), R ^S3 is a group represented by formula (S1-1), and specific examples of when R ^S2 and R ^S3 are bonded to each other to form a ring include N-methyl-2- Pyrrolidone and N-ethyl-2-pyrrolidone, etc.

Among the nitrogen-containing compounds represented by formula (S1), specific examples of when R ^S3 is a group represented by formula (S1-2) include N,N,N',N'-tetramethylurea, N,N, N', N'-tetraethylurea, etc.

Among the above-mentioned examples of nitrogen-containing compounds represented by the formula (S1), particularly preferred compounds include N,N-dimethylformamide, N,N-dimethylacetamide, N,N,2 - Trimethylacrylamide and N,N,N',N'-tetramethylurea. Among these, N,N,2-trimethylacrylamide and N,N,N',N'-tetramethylurea are preferred. The boiling point of N,N,2-trimethylacrylamide at atmospheric pressure is 175°C, and the boiling point of N,N,N',N'-tetramethylurea at atmospheric pressure is 177°C. Thus, N,N,2-trimethylacrylamide and N,N,N',N'-tetramethylurea have comparatively lower boiling points. Therefore, when using a coating composition containing at least one solvent (S) selected from N,N,2-trimethylacrylamide and N,N,N',N'-tetramethylurea, When the polyimide resin is formed, the solvent (S) is unlikely to remain in the polyimide resin produced by heating, and it is difficult to cause a decrease in the mechanical properties of the obtained polyimide resin.

Furthermore, N,N,2-trimethylacrylamide and N,N,N',N'-tetramethylurea will not be as SVHC (Substance of Very High Concern) in the EU (European Union) REACH regulations , Highly worrying substances) are designated as substances with concern about harmfulness, and are also useful for substances with low harmfulness.

The content of the solvent (S) in the paint composition is not particularly limited within the range that does not hinder the object of the present invention. The content of the solvent (S) in the paint composition can be appropriately adjusted according to the solid content in the paint composition. The solid content in the paint composition is, for example, in the range of 5% by mass to 99.9% by mass, preferably 5% by mass to 70% by mass, more preferably 10% by mass to 60% by mass.

＜Heat base generator (B)＞ The coating composition may contain a thermal base generator (B) that generates a basic nitrogen-containing heterocyclic compound by heating for the purpose of producing polyamide resin from polyamide acid (A) that is fired well. ).

The basic nitrogen-containing heterocyclic compound that generates the thermal base generator (B) can be an aliphatic ring compound or an aromatic compound. When the basic nitrogen-containing heterocyclic compound is a compound having two or more monocyclic rings condensed, the two or more monocyclic rings may consist of only aliphatic rings, or only aromatic rings, or may consist of aliphatic rings and aromatic rings. combination composition.

Examples of basic nitrogen-containing heterocyclic compounds that generate the thermal base generator (B) include pyrrolidine, pyrazolidine, imidazoline, triazolidine, tetrazoline, pyrroline, pyrazoline, and imidazoline. , triazoline, tetrazoline, pyrrole, pyrazole, imidazole, triazole and tetrazole and other nitrogen-containing 5-membered ring compounds; Nitrogen-containing 6-membered rings; these compounds are substituted by one or more substituents; these compounds are condensed with cyclopentane, cyclohexane, benzene, etc. When the basic nitrogen-containing heterocyclic compound has a substituent on the nitrogen-containing heterocyclic ring, examples of the substituent include the same groups as R ¹ , R ^{2 ,} and R ³ in the formula (B1) described later.

Since the effect of promoting the generation of polyimide resin from polyamic acid (A) is good, etc., the basic nitrogen-containing heterocyclic compound as a component of the thermal base generator (B) is preferably the following formula (B1 ) represents an imidazole compound, (In formula (B1), R ¹ , R ² and R ³ are independently hydrogen atom, halogen atom, hydroxyl group, silyl group, silanol group, nitro group, nitroso group, sulfonate group, phosphine group, phosphine group , phosphonate or organic groups).

Examples of organic groups in R ¹ , R ² and R ³ include alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, and aralkyl. This organic group may contain a bond or a substituent other than a hydrocarbon group such as a hetero atom in the organic group. Moreover, this organic group may be linear, branched, or cyclic. This organic group is usually monovalent, but it may be a divalent or higher organic group when forming a ring structure.

R ¹ and R ² may be bonded to these to form a ring structure, and a bond of a heteroatom may be further included. As a ring structure, a heterocycloalkyl group, a heteroaryl group, etc. are mentioned, and a condensed ring may be sufficient.

The bonds included in the organic groups of R ¹ , R ² and R ³ are not particularly limited as long as they do not impair the effects of the present invention. The organic group may contain linkages including heteroatoms of oxygen atoms, nitrogen atoms, silicon atoms, and the like. Specific examples of bonds containing heteroatoms include ether bonds, carbonyl bonds, thiocarbonyl bonds, ester bonds, amide bonds, urethane bonds, and imide bonds (-N=C(-R) -, -C(=NR)-: R represents a hydrogen atom or an organic group), a carbonate bond, a sulfonyl bond, an azo bond, etc.

From the viewpoint of heat resistance of the imidazole compound, the bond including a heteroatom that the organic groups of R ¹ , R ² and R ³ may have is preferably an ether bond, a carbonyl bond, a thiocarbonyl bond, an ester bond, or an acyl bond. Amine bond, urethane bond, imide bond (-N=C(-R)-, -C(=NR)-: R represents a hydrogen atom or a monovalent organic group), carbonate bond, sulfonate Acyl group bond.

When the organic groups of R ¹ , R ² and R ³ are substituents other than hydrocarbon groups, R ¹ , R ² and R ³ are not particularly limited as long as they do not impair the effect of the present invention. Specific examples of R ¹ , R ² and R ³ are as mentioned above, halogen atom, hydroxyl group, silyl group, silanol group, nitro group, nitroso group, sulfonate group, phosphino group, phosphinyl group and phosphonate group. Hydrogen atoms contained in the above-mentioned substituents may be substituted with hydrocarbon groups. Moreover, the hydrocarbon group contained in the said substituent may be any of linear, branched and cyclic.

R ¹ , R ² and R ³ are preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aryl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and Halogen atom, more preferably hydrogen atom.

The thermal base generator (B) is not particularly limited as long as it is a compound capable of generating a basic nitrogen-containing heterocyclic compound by heating. For compounds that generate amines by the action of heat (thermal base generators) that have been blended into various compositions conventionally, by substituting the skeleton derived from amines generated during heating with desired bases The skeleton of the nitrogen-containing heterocyclic compound is obtained to obtain a compound used as a thermal base generator (B).

Examples of suitable thermal base generators (B) include compounds represented by the following formula (B2): (In formula (B2), R ¹ , R ² and R ³ are the same as those in formula (B1), R ^b1 and R ^b2 independently represent hydrogen atom, halogen atom, hydroxyl group, silyl group, silanol group, Nitro, nitroso, sulfinate, sulfo, sulfonate, phosphino, phosphinyl, phosphono, phosphonate or organic, R ^b3 , R ^b4 , R ^b5 , R ^b6 and R ^b7 independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a silyl group, a silanol group, a nitro group, a nitroso group, a sulfinic acid group, a sulfo group, a sulfonate group, a phosphino group, a phosphine group, a phosphino group, and a phosphine group. Acid group, amine group, ammonium group or organic group, R ^b3 , R ^b4 , R ^b5 , R ^b6 and R ^b7 can be bonded to two or more of them to form a ring structure, and may include heteroatom bonds ).

In formula (B2), R ¹ , R ² and R ³ are as explained for formula (B1).

In formula (B2), R ^b1 and R ^b2 independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a silyl group, a silanol group, a nitro group, a nitroso group, a sulfinate group, a sulfo group, a sulfonate group, a phosphino group , phosphine group, phosphono group, phosphonate group or organic group.

Examples of the organic groups in R ^b1 and R ^b2 include those exemplified for R ¹ , R ² and R ³ . The organic group is the same as the case of R ¹ , R ² and R ³ , and heteroatoms may be included in the organic group. Moreover, this organic group may be linear, branched, or cyclic.

Among the above, R ^b1 and R ^b2 are preferably each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 4 to 13 carbon atoms, or a group having 4 to 13 carbon atoms. Cycloalkenyl group, aryloxyalkyl group with 7 to 16 carbon atoms, aralkyl group with 7 to 20 carbon atoms, alkyl group with cyano group with 2 to 11 carbon atoms, carbon group with hydroxyl group Alkyl group with 1 to 10 atoms, alkoxy group with 1 to 10 carbon atoms, amido group with 2 to 11 carbon atoms, acyl group with 1 to 10 carbon atoms, 2 or more carbon atoms Ester groups of 11 or less (-COOR, -OCOR: R represents a hydrocarbon group), aryl groups with 6 to 20 carbon atoms, aryl groups with 6 to 20 carbon atoms substituting electron-pushing groups and/or electron-withdrawing groups group, benzyl group substituting electron-pushing group and/or electron-withdrawing group, cyano group. More preferably, both R ^b1 and R ^b2 are hydrogen atoms, or R ^b1 is a methyl group, and R ^b2 is a hydrogen atom.

In formula (B2), R ^b3 , R ^b4 , R ^b5 , R ^b6 and R ^b7 independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a mercapto group, a sulfide group, a silyl group, a silanol group, a nitro group, a nitroso group , sulfinic acid group, sulfonic acid group, sulfonic acid group, phosphine group, phosphinyl group, phosphonyl group, phosphonate group, amine group, ammonium group or organic group.

Examples of the organic groups for R ^b3 , R ^b4 , R ^b5 , R ^b6 and R ^b7 include those exemplified for R ¹ , R ² and R ³ . This organic group is the same as the case of R ¹ , R ² and R ³ , and the organic group may contain a bond or a substituent other than a hydrocarbon group such as a heteroatom. Moreover, this organic group may be linear, branched, or cyclic.

For R ^b3 , R ^b4 , R ^b5 , R ^b6 and R ^b7 , two or more of them may be bonded to form a ring structure. R ^b3 , R ^b4 , R ^b5 , R ^b6 and R ^b7 may each include: a bond including a heteroatom. As a ring structure, a heterocycloalkyl group, a heteroaryl group, etc. are mentioned, and a condensed ring may be sufficient. For example, R ^b3 , R ^b4 , R ^b5 , R ^b6 , and R ^b7 may be bonded to two or more of them, sharing the atoms bonded to the benzene ring of R ^b3 , R ^b4 , R ^b5 , R ^b6 , and R ^b7 , and Form condensation rings of naphthalene, anthracene, phenanthrene, indene, etc. When forming a condensed ring, it is preferable from the point of view of making the absorption wavelength longer.

Among the above, R ^b3 , R ^b4 , R ^b5 , R ^{b6 ,} and R ^b7 are each independently preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and a cycloalkyl group having 4 to 13 carbon atoms. , cycloalkenyl group with 4 to 13 carbon atoms, aryloxyalkyl group with 7 to 16 carbon atoms, aralkyl group with 7 to 20 carbon atoms, cyano group with 2 to 11 carbon atoms The following alkyl groups, alkyl groups having a hydroxyl group with 1 to 10 carbon atoms, alkoxy groups with 1 to 10 carbon atoms, amido groups with 2 to 11 carbon atoms, and 1 to 10 carbon atoms An acyl group, an ester group with 2 to 11 carbon atoms, an aryl group with 6 to 20 carbon atoms, an aryl group with 6 to 20 carbon atoms substituting an electron-pushing group and/or an electron-withdrawing group, Substituting benzyl, cyano and nitro for electron-pushing and/or electron-withdrawing groups.

Among the compounds represented by the above formula (B2), compounds represented by the following formula (B3) are preferred, (In formula (B3), R ¹ , R ² and R ³ are synonymous with formula (B1) and (B2). R ^b1 -R ^b6 are synonymous with formula (B2). ^{R b8} represents a hydrogen atom or an organic group. R ^b3 and R ^b4 do not become hydroxyl groups. Two or more of ^{R b3} , R ^b4 , R ^b5 , and R ^b6 may be bonded to form a ring structure, which may include a heteroatom bond).

Since the compound represented by the formula (B3) has a substituent -OR ^b8 , it has excellent solubility in the solvent (S).

In formula (B3), R ^b8 is a hydrogen atom or an organic group. When R ^b8 is an organic group, examples of the organic group include those exemplified for R ¹ , R ² and R ³ . The organic group may contain heteroatoms in the organic group. Moreover, this organic group may be linear, branched, or cyclic. R ^b8 is preferably a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, more preferably a methyl group.

Among the compounds represented by the formula (B1), specific examples of compounds that are particularly suitable as the thermal base generator (B) are shown below.

Moreover, the imidazole compound represented by following formula (B4) is also suitable as a thermal base generator (B). (In formula (B4), R ¹ , R ² and R ³ are the same as those in formula (B1), R ^b9 represents a hydrogen atom or a monovalent organic group, R ^b10 represents an aromatic group that may have a substituent , R ^b9 can be bonded with another R ^b9 or R ^b10 to form a ring structure).

In formula (B4), R ^b9 is a hydrogen atom or a monovalent organic group. It does not specifically limit as a monovalent organic group, For example, the alkyl group which may have a substituent, the aromatic group which may have a substituent, etc. may be sufficient. When R ^b9 is an alkyl group, the alkyl group may have an ester bond or the like in the chain.

As an alkyl group, the same as R ^b11 etc. in the formula (B4a) mentioned later can be mentioned, for example. The number of carbon atoms in the alkyl group is preferably from 1 to 40, more preferably from 1 to 30, particularly preferably from 1 to 20, most preferably from 1 to 10. As a substituent which this alkyl group may have, it may be the same as the substituent which R ^b11 in formula (B4a) mentioned later may have, that is, an alkylene group, for example.

The aromatic group which may have a substituent is the same as R ^b10 in formula (B4a) described later, preferably an aryl group, more preferably a phenyl group. The aromatic group which may have a substituent as R ^b9 may be the same as R ^b10 , or may be different. In formula (B4), R ^b9 on one side is preferably a hydrogen atom, more preferably R ^b9 on one side is a hydrogen atom, and R ^b9 on the other side is an alkyl group that may have a substituent or an alkyl group that may have a substituent. Aromatic base. In formula (B4), R ^b9 may be bonded to another R ^b9 or R ^b10 to form a ring structure. For example, when at least one R ^b9 is an optionally substituted alkyl group, R ^b9 may be bonded to another R ^b9 or R ^b10 to form a ring structure.

The imidazole compound represented by the formula (B4) may also be a compound represented by the following formula (B4a).

(In formula (B4a), R ¹ , R ² and R ³ are the same as those in formula (B1), R ^b11 is a hydrogen atom or an alkyl group, R ^b10 is an aromatic group that may have a substituent, R ^b12 It is an alkylene group which may have a substituent, and R ^b12 may be bonded to R ^b10 to form a ring structure).

In formula (B4a), R ^b11 is a hydrogen atom or an alkyl group. When R ^b11 is an alkyl group, the alkyl group may be a straight-chain alkyl group or a branched-chain alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably from 1 to 20, more preferably from 1 to 10, and still more preferably from 1 to 5.

Specific examples of alkyl groups suitable as R ^b11 include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n- Pentyl, isopentyl, tert-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethyl-n-hexyl, n-nonyl, n-decyl, n-undecyl base, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl , n-nonadecyl and n-eicosyl.

In formula (B4a), R ^b10 is an aromatic group which may have a substituent. The aromatic group which may have a substituent may be an aromatic hydrocarbon group which may have a substituent, or may be an aromatic heterocyclic group which may have a substituent.

The type of aromatic hydrocarbon group is not particularly limited within the range that does not hinder the object of the present invention. The aromatic hydrocarbon group may be a monocyclic aromatic group, a group formed by condensing two or more aromatic hydrocarbon groups, or a group formed by bonding two or more aromatic hydrocarbon groups with a single bond. The aromatic hydrocarbon group is preferably phenyl, naphthyl, biphenyl, anthracenyl, or phenanthrenyl.

The type of aromatic heterocyclic group is not particularly limited insofar as it does not hinder the object of the present invention. The aromatic heterocyclic group may be a monocyclic group or a polycyclic group. The aromatic heterocyclic group is preferably pyridyl, furyl, thienyl, imidazolyl, pyrazolyl, oxazolyl, thiazolyl, isoxazolyl, isothiazolyl, benzoxazolyl, benzo Thiazolyl and benzimidazolyl.

Examples of substituents that a phenyl group, a polycyclic aromatic hydrocarbon group or an aromatic heterocyclic group may have include a halogen atom, a hydroxyl group, a silyl group, a silanol group, a nitro group, a nitroso group, a sulfinic acid group, a sulfo group, Sulfonate, phosphino, phosphinoxide, phosphono, phosphonate, amine, ammonium and organic groups. When a phenyl group, a polycyclic aromatic hydrocarbon group, or an aromatic heterocyclic group has a plurality of substituents, the plurality of substituents may be the same or different.

When the substituent which the aromatic group has is an organic group, an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, an aralkyl group etc. are mentioned as this organic group. This organic group may contain a bond or a substituent other than a hydrocarbon group such as a hetero atom in the organic group. In addition, this organic group may be any of a straight chain, a branched chain, a ring, and a combination of these structures. This organic group is usually monovalent, but it may be a divalent or higher organic group when forming a ring structure.

When there is a substituent on the carbon atom adjacent to the aromatic group, two substituents bonded to the adjacent carbon atom may bond to form a ring structure. As a cyclic structure, an aliphatic hydrocarbon ring or an aliphatic ring containing a heteroatom is mentioned.

When the substituent of the aromatic group is an organic group, the bond included in the organic group is not particularly limited as long as it does not impair the effect of the present invention, and the organic group may contain oxygen atoms, nitrogen atoms, silicon atoms, etc. Contains linkages of heteroatoms. Specific examples of bonds containing heteroatoms include ether bonds, carbonyl bonds, thiocarbonyl bonds, ester bonds, amide bonds, urethane bonds, and imide bonds (-N=C(-R) -, -C(=NR)-: R represents a hydrogen atom or an organic group), a carbonate bond, a sulfonyl bond, an azo bond, etc.

Bonds including heteroatoms that the organic group may have are preferably ether bonds, carbonyl bonds, thiocarbonyl bonds, or ester bonds from the viewpoint of heat resistance of the imidazole compound represented by formula (B4) or formula (B4a). , amide bond, amine bond (-NR-: R represents a hydrogen atom or a 1-valent organic group) urethane bond, imide bond (-N=C(-R)-, -C(= NR)-: R represents a hydrogen atom or a monovalent organic group), a carbonate bond, or a sulfonyl bond.

When the organic group is a substituent other than a hydrocarbon group, the type of the substituent other than a hydrocarbon group is not particularly limited insofar as it does not hinder the object of the present invention. Specific examples of substituents other than hydrocarbon groups include halogen atoms, hydroxyl groups, mercapto groups, sulfide groups, cyano groups, isocyano groups, cyanoxy groups, isocyanato groups, thiocyano groups, isothiocyano groups, and silyl groups. , silanol, alkoxy, alkoxycarbonyl, amino, monoalkylamino, dialkylaluminum, monoarylamino, diarylamine, aminoformyl, thioamine Formyl group, nitro group, nitroso group, carboxylate group, acyl group, acyloxy group, sulfinate group, sulfonate group, phosphine group, phosphine oxide group, phosphonate group, alkyl ether group, Alkenyl ether group, aryl ether group, etc. Hydrogen atoms contained in the above-mentioned substituents may also be substituted by hydrocarbon groups. Moreover, the hydrocarbon group contained in the said substituent may be any of linear, branched and cyclic.

As a substituent of a phenyl group, a polycyclic aromatic hydrocarbon group, or an aromatic heterocyclic group, an alkyl group having 1 to 12 carbon atoms, an aryl group having 1 to 12 carbon atoms, and an aryl group having 1 to 12 carbon atoms are preferable. An alkoxy group having 12 or less carbon atoms, an aryloxy group having 1 or more carbon atoms but not more than 12, an arylamino group having 1 or more carbon atoms and not more than 12, and a halogen atom.

As R ^b10 , since the imidazole compound represented by formula (B4) or formula (B4a) can be synthesized cheaply and easily, and has good solubility in water or organic solvents of the imidazole compound, benzene which may have a substituent is preferred. base, furyl, thienyl.

In formula (B4a), R ^b12 is an alkylene group which may have a substituent. The substitution which an alkylene group may have is not specifically limited in the range which does not hinder the object of this invention. Specific examples of the substituent that the alkylene group may have include a hydroxyl group, an alkoxy group, an amino group, a cyano group, and a halogen atom. The alkylene group may also be a straight-chain alkylene group or a branched-chain alkylene group, preferably a straight-chain alkylene group. The number of carbon atoms in the alkylene group is not particularly limited, but is preferably from 1 to 20, more preferably from 1 to 10, particularly preferably from 1 to 5. Also, the number of carbon atoms in the alkylene group does not include the carbon atoms of the substituent bonded to the alkylene group.

The alkoxy group as a substituent bonded to an alkylene group may be a straight-chain alkoxy group or a branched-chain alkoxy group. The number of carbon atoms of the alkoxy group as a substituent is not particularly limited, but is preferably from 1 to 10, more preferably from 1 to 6, and particularly preferably from 1 to 3.

The amine group as a substituent bonded to an alkylene group may be a monoalkylamine group or a dialkylamine group. The alkyl group contained in the monoalkylamine group or the dialkylamine group may also be a straight-chain alkyl group or a branched-chain alkyl group. The number of carbon atoms of the alkyl group contained in the monoalkylamine group or the dialkylamine group is not particularly limited, but is preferably from 1 to 10, more preferably from 1 to 6, particularly preferably from 1 to 3.

Specific examples of the alkylene group suitable as R ^b12 include methylene, ethane-1,2-diyl, n-propane-1,3-diyl, n-propane-2,2-diyl , n-butane-1,4-diyl, n-pentane-1,5-diyl, n-hexane-1,6-diyl, n-heptane-1,7-diyl, n -octane-1,8-diyl, n-nonane-1,9-diyl, n-decane-1,10-diyl, n-undecane-1,11-diyl, n- Dodecane-1,12-diyl, n-tridecane-1,13-diyl, n-tetradecane-1,14-diyl, n-pentadecane-1,15-diyl, n-hexadecane-1,16-diyl, n-heptadecane-1,17-diyl, n-octadecane-1,18-diyl, n-nonadecane-1,19-diyl and n-eicosane-1,20-diyl.

Among the imidazole compounds represented by the above formula (B4), a compound represented by the following formula (B4-1a) is preferable in view of being inexpensive and easily synthesized.

(In formula (B4-1a), R ¹ , R ² and ^R3 are the same as those in formula (B1), R ^b9 is the same as formula (B4), R ^b13 , R ^b14 , R ^b15 , R ^b16 and R ^b17 are independently a hydrogen atom, a halogen atom, a hydroxyl group, a silyl group, a silanol group, a nitro group, a nitroso group, a sulfinic acid group, a sulfo group, a sulfonate group, a phosphino group, a phosphinyl group, a phosphono group, Phosphonic acid group, amine group, ammonium group or organic group. Among ^{R b13} , R ^b14 , R ^b15 , R ^b16 and R ^b17 , at least two can be bonded to form a ring structure. R ^b9 can be bonded to R ^b15 to form a circular structure). Furthermore, in formula (B4-1a), R ^b13 , R ^b14 , R ^b15 , R ^b16 and R ^b17 may all be hydrogen atoms. Also, from the viewpoint of the solubility of the compound represented by the formula (B4-1) in the solvent (S), at least one of R ^b13 , R ^b14 , R ^b15 , R ^b16 and R ^b17 is preferably a hydrogen atom outside the base.

R ^b13 , R ^b14 , R ^b15 , R ^b16 and R ^b17 are the same as those in formula (B4-1) described later. In the formula (B4-1a), R ^b9 may be bonded to R ^b15 to form a ring structure. For example, when R ^b9 is an alkyl group which may have a substituent, R ^b9 may be bonded to R ^b15 to form a ring structure.

Among the imidazole compounds represented by the above formula (B4a) or formula (B4-1a), the following formula (B4-1) is preferable in terms of being cheap and easy to synthesize, and having excellent solubility in water or organic solvents The compound represented by is more preferably represented by the formula (B4-1), wherein R ^b12 is a methylene group.

(In formula (B4-1), R ¹ , R ² and ^R3 are the same as those in formula (B1), R ^b11 and R ^b12 are the same as those in formula (B4a), R ^b13 , R ^b14 , R ^b15 , R ^b16 and R ^b17 are independently a hydrogen atom, a halogen atom, a hydroxyl group, a silyl group, a silanol group, a nitro group, a nitroso group, a sulfinate group, a sulfo group, a sulfonate group, a phosphino group, Phosphinyl group, phosphonyl group, phosphonate group, amine group, ammonium group or organic group. Among ^{R b13} , R ^b14 , R ^b15 , R ^b16 and R ^b17 , at least two may be bonded to form a ring structure. R ^b12 may be bonded to R ^b15 to form a ring structure). Furthermore, in formula (B4-1), R ^b13 , R ^b14 , R ^b15 , R ^b16 and R ^b17 may all be hydrogen atoms. Also, from the viewpoint of the solubility of the compound represented by the formula (B4-1) in the solvent (S), at least one of R ^b13 , R ^b14 , R ^b15 , R ^b16 and R ^b17 is preferably a hydrogen atom outside the base.

When R ^b13 , R ^b14 , R ^b15 , R ^b16 and R ^b17 are organic groups, the organic group is the same as the organic group that R ^b10 of the formula (B4a) has as a substituent. R ^b13 , R ^b14 , R ^b15 and R ^b16 are preferably hydrogen atoms from the viewpoint of solubility in the solvent (S) of the imidazole compound.

Among them, at least one of R ^b13 , R ^b14 , R ^b15 , R ^b16 and R ^b17 is preferably the following substituent, and it is particularly preferred that R ^b17 is the following substituent. When R ^b17 is the following substituent, R ^b13 , R ^b14 , R ^b15 and R ^b16 are preferably hydrogen atoms. -OR ^b18 (R ^b18 is a hydrogen atom or an organic group).

When R ^b18 is an organic group, the organic group is the same as the organic group that R ^b10 of the formula (B4a) has as a substituent. R ^b18 is preferably an alkyl group, more preferably an alkyl group having 1 to 8 carbon atoms, particularly preferably an alkyl group having 1 to 3 carbon atoms, most preferably a methyl group.

Among the compounds represented by the above formula (B4-1), compounds represented by the following formula (B4-1-1) are preferred. (In formula (B4-1-1), R ¹ , R ² and ^R3 are the same as those in formula (B1), R ^b11 is the same as formula (B4a), R ^b19 , R ^b20 , R ^b21 , R ^b22 and R ^b23 are independently hydrogen atom, hydroxyl group, silyl group, silanol group, nitro group, nitroso group, sulfinic acid group, sulfo group, sulfonate group, phosphino group, phosphinyl group, phosphono group, phosphine group acid group, amine group, ammonium group or organic group. However, at least one of R ^b19 , R ^b20 , R ^b21 , R ^b22 and R ^b23 is a group other than a hydrogen atom).

Among the compounds represented by the formula (B4-1-1), preferably at least one of R ^b19 , R ^b20 , R ^b21 , R ^b22 and R ^b23 is the group represented by the aforementioned -OR ^b18 , particularly preferably R ^b23 is The base represented by -OR ^b18 . When R ^b23 is a group represented by -OR ^b18 , R ^b19 , R ^b20 , R ^b21 and R ^b22 are preferably hydrogen atoms.

Suitable specific examples of the imidazole compound represented by formula (B4) or formula (B4a) include the following compounds.

The content of the thermal base generator (B) in the paint composition is preferably from 1 to 20 parts by mass, more preferably from 2 to 10 parts by mass, based on 100 parts by mass of the total solid content. By using the thermal base generator (B) in the amount within this range, it is not accompanied by excessive volatilization or sublimation of the thermal decomposition product of the thermal base generator (B), and the thermal base generator (B) from polyamic acid (A) can be effectively promoted The generation of polyamide resin.

＜Other ingredients＞ The paint composition may contain various additives as necessary. Examples of additives include coloring agents, dispersants, sensitizers, adhesion promoters, antioxidants, ultraviolet absorbers, anti-aggregating agents, antifoaming agents, and surfactants. Also, the paint composition may contain various fillers or reinforcing materials as necessary. The usage-amount of various additives is not specifically limited in the range which does not hinder the objective of this invention. The mass of the solid content of the paint composition may be appropriately adjusted, for example, within a range of 0.001 mass % to 60 mass %, preferably 0.05 mass % to 5 mass %. The usage-amount of a filler or a reinforcing material is not specifically limited in the range which does not hinder the object of this invention. The amount of the filler or reinforcing material used is usually preferably from 1% by mass to 300% by mass, more preferably from 5% by mass to 200% by mass, and more preferably with respect to the mass of the polyamic acid (A). Preferably, it is not less than 10% by mass and not more than 100% by mass.

As described above, according to the above-mentioned coating composition, it is possible to form a polyimide resin that is less colored and has excellent mechanical properties such as elongation at break and low thermal expansion.

≪Manufacturing method of paint composition≫ As suitable manufacturing method of coating composition, can enumerate: comprise Polymerize tetracarboxylic dianhydride (A1) and aromatic diamine compound (A2) in solvent (S) to generate polyamic acid (A) or A method of mixing tetracarboxylic dianhydride (A1) and aromatic diamine compound (A2) to produce polyamic acid (A) and then mixing the isolated polyamic acid (A) with solvent (S) . As mentioned above, tetracarboxylic dianhydride (A1) consists only of alicyclic tetracarboxylic dianhydride (A1-1) and alicyclic tetracarboxylic dianhydride (A1-2). The ratio of the mass of alicyclic tetracarboxylic dianhydride (A1-2) to the number of moles of tetracarboxylic dianhydride (A1) is 0.1 mol % or more and 6 mol % or less.

The method for polymerizing tetracarboxylic dianhydride (A1) and aromatic diamine compound (A2) is as described above. Also, when producing a coating composition, when isolating polyamic acid from a polymerization reaction solution containing polyamic acid (A), it can be used in conjunction with the isolated polyamic acid (A) in the polymerization. solvent or unreacted monomer.

≪Manufacturing method of polyimide resin≫ It can be formed by the forming step including forming the above-described coating composition, and A method of imidizing the formed coating composition by heating and imidizing it to produce a polyimide resin.

The shape of the paint composition to be molded when molding the paint composition is not particularly limited. The method for forming the coating composition is not particularly limited. For example, a method of injecting a coating composition into a mold having a desired shape, a method of filling a mold with a coating composition using a squeegee, or a method of coating a coating composition on a substrate may be mentioned. Among these methods, since the polyimide resin film is in great demand, or it is easy to remove the solvent (S) from the coating composition well when the polyimide resin is produced, it is preferable to coat the coating on the substrate. Method of composition. After the coating composition is applied, it is placed in a heating and/or vacuum or reduced pressure environment to dry the coating film and form a dry film.

The temperature for heating the paint composition or the paint composition after the drying step is not particularly limited as long as it is a temperature at which the polyimide resin with desired properties can be obtained. The temperature for heating polyamic acid is preferably from 120°C to 450°C, more preferably from 150°C to 435°C. By heating the paint composition at a temperature in such a range, thermal deterioration or thermal decomposition of the produced polyimide resin can be suppressed, the solvent (S) can be removed, and the polyimide resin can be produced. Also, since it is easy to form a polyimide resin with a high glass transition temperature, good elongation at break, low thermal expansion, and less coloring, the polyimide resin is kept at a temperature of 70°C or higher and 120°C or lower for 10 minutes to 2 hours. Furthermore, it is also preferable to produce polyimide resin by heating at 150° C. to 435° C. for 5 minutes to 2 hours while gradually increasing the temperature.

According to the method for producing a polyimide resin described above, it is possible to produce a polyimide resin that is less colored and has excellent mechanical properties such as elongation at break and low thermal expansion. [Example]

Hereinafter, although the present invention will be described in detail through examples, the scope of the present invention is not limited to these examples.

In Examples and Comparative Examples, Compound 1-1 of the following formula was used as alicyclic tetracarboxylic dianhydride (A1-1).

As alicyclic tetracarboxylic dianhydride (A1-2), the following compound 1-2a, 1-2b, and 1-2c were used.

In Examples and Comparative Examples, a compound of the following formula was used as the thermal base generator (B).

[Examples 1-9 and Comparative Examples 1-4] Heat a three-neck flask with a capacity of 30mL with a heat gun to fully dry it. Next, the environment in the three-necked flask was replaced with nitrogen, and the inside of the three-necked flask was set as a nitrogen environment. In the three-necked flask, add 0.2045 g (0.90 mmol: Nippon Junyo Pharmaceutical Co., Ltd.: DABAN) of 4,4'-diaminobenzylaniline as the aromatic diamine compound (A2), and then add N, N,N',N'-Tetramethylurea (TMU). The contents of the three-necked flask were stirred to obtain a slurry liquid in which aromatic diamine (DABAN) was dispersed in TMU. The amount of TMU is the same mass as the total of the mass of the tetracarboxylic dianhydride (A1) and the mass of the aromatic diamine compound (A2). Next, 0.90 mmol of tetracarboxylic dianhydride (A1) of the kind and quantity listed in Table 1 was added in the three-necked flask. Then, the contents of the flask were stirred at room temperature (25° C.) for 12 hours under a nitrogen atmosphere to obtain a reaction liquid. To the reaction solution containing the polyamic acid obtained in this way, 10% by mass of hot alkali was added to the total mass of the tetracarboxylic dianhydride (A1) and the mass of the aromatic diamine compound (A2) Generator (B). Next, the reaction liquid containing polyamic acid (A) was diluted with TMU so that the concentration of polyamic acid (A) might become 18 mass %, and the coating composition of each Example and each comparative example was obtained.

Using the coating compositions of the various examples and comparative examples obtained as above, according to the following method, film formation of polyimide resin films was carried out, and the yellowness (YI) of the formed polyimide resin films was measured. , Light transmittance, coefficient of thermal expansion (CTE), elongation at break evaluation. Record these evaluation results in Table 1.

＜Film Formation Method of Polyimide Resin Film＞ On a glass substrate (100 mm in length, 100 mm in width, and 1.3 mm in thickness), the coating composition obtained as described above was spin-coated so that the thickness of the coating film after heating and hardening became 13 μm to form a coating film. Next, the glass substrate provided with the coating film was vacuum-dried under the conditions of a temperature of 50° C. and a pressure of 13 Pa to remove the solvent in the coating film. After removal of the solvent, the glass substrate provided with the coating film was put into an inert oven flowing nitrogen at a flow rate of 3 L/min. In an inert oven, under a nitrogen atmosphere, at a temperature of 80°C, let stand for 0.5 hours, then stand at a temperature of 300°C for 0.5 hours, and then heat at a temperature of 435°C (final heating temperature) for 10 minutes, so that The coating film was cured to obtain a polyimide-coated glass coated with a thin film (polyimide film) made of polyimide. The obtained polyimide-coated glass was immersed in hot water at 90°C, and the polyimide film was peeled off from the glass substrate to obtain a polyimide film (100 mm in length, 100 mm in width, and 13 μm in thickness) .

＜Yellowness (YI), light transmittance＞ The values (unit: %) and yellowness (YI) of the light transmittance (unit: %) and the yellowness (YI) of the polyimide film of each embodiment and the comparative example are obtained by using the trade name "haze meter NDH" manufactured by Nippon Denshoku Industries Co., Ltd. -5000" was used as a measuring device, and it was determined in accordance with JIS K7361-1 (issued in 1997). The light transmittance is the value at the wavelength of light from 380nm to 780nm. Regarding the degree of yellowness, the evaluation results are judged according to the following criteria. 〇: YI value is less than 5.0. x: YI value is 5.0 or more.

＜Coefficient of Thermal Expansion (CTE)＞ From the polyimide films of the respective examples and comparative examples, a film for measurement having a size of 20 mm in length and 5 mm in width was formed. Next, by using a thermomechanical analyzer (trade name "TMA-60" manufactured by Shimadzu Corporation) as a measurement device, the obtained thin film for measurement was measured under a nitrogen atmosphere at a temperature increase rate of 10°C/ Changes in the length of the sample at 100°C to 400°C when the temperature is raised from 30°C to 200°C, once cooled to 30°C, and then heated from 30°C to 500°C at a heating rate of 10°C/min. , Obtain the average value of the change in length per 1°C between 100°C and 400°C. Still, the tensile mode was set at 49mN.

＜Elongation at break＞ For the polyimide films of the respective examples and comparative examples, a product named "SUPER" manufactured by DUMBBEL Co., Ltd. was installed on an SD-type lever type sample cutter (a cutter made by DUMBBEL Co., Ltd. (model SDL-200)). DUMBBELL CUTTER (type: SDMK-1000-D, in accordance with A22 standard of JIS K7139 (issued in 2009))", the size of the polyimide film becomes the overall length: 75mm, the distance between the label parts: 57mm, the length of the parallel part: 30mm, radius of the shoulder: 30mm, width of the end: 10mm, width of the parallel part of the center: 5mm, thickness: 13μm, and the test piece of the DUMBBEL shape (except that the thickness is set to 13μm, according to the A test piece according to JIS K7139 type A22 (reduced scale test piece)) was prepared as a measurement sample. Next, using a tension-type universal testing machine (model "UCT-10T" manufactured by A&D Co., Ltd.), measure the sample so that the width between the grips becomes 57 mm, and the width of the pinched part becomes 10 mm (full width of the end) After the configuration is carried out, the tensile test of the tensile measurement sample is carried out under the conditions of the load full scale: 0.05kN, and the test speed: 1-300mm/min, and the value of the elongation at break is obtained. The above test is based on the test of JIS K7162 (published in 1994). In addition, the value (%) of the elongation at break is defined as the length of the parallel portion of the test piece (=length of the parallel portion: 30mm) as L0, and the length of the parallel portion of the test piece until it breaks (the test piece at the time of fracture) The length of the parallel part: 30mm+α) is defined as L, and the following formula is calculated: [Elongation at break (%)]={(L-L0)/L0}×100 Find out. Regarding the elongation at break, the evaluation results were judged on the basis of the following criteria. ◎: The elongation at break is 12.5% or more. ○: Elongation at break is 10.0% or more and less than 12.5%. ×: Elongation at break is less than 10.0%.

According to Table 1, it is understood that the use of tetracarboxylic dianhydride (A) composed of alicyclic tetracarboxylic dianhydride (A1-1) and alicyclic tetracarboxylic dianhydride (A1-2), and aromatic A polymer of a diamine compound (A2), wherein the mass ratio of the alicyclic tetracarboxylic dianhydride (A1-2) to the number of moles of the tetracarboxylic dianhydride (A1) is 0.1 mol% or more and 6 mol When the coating composition of the embodiment containing the polyamic acid (A) is less than 50 %, a polyimide resin having less coloring and excellent mechanical properties can be formed. On the other hand, according to the comparative examples, it is understood that use: only use alicyclic tetracarboxylic dianhydride (A1-1) as polyamic acid (A) to prepare, or alicyclic tetracarboxylic dianhydride (A1 -2) When the ratio of the mass of the polyamic acid (A) to the molar number of the tetracarboxylic dianhydride (A1) exceeds 6 mol%, it is difficult to have both less coloring and excellent mechanical properties. .

Claims (7)

A coating composition, characterized by comprising polyamic acid (A) and solvent (S), the aforementioned polyamic acid (A) is the combination of tetracarboxylic dianhydride (A1) and aromatic diamine compound (A2) Polymer, the aforementioned tetracarboxylic dianhydride (A1) is an alicyclic tetracarboxylic dianhydride (A1-1) of a compound represented only by the following formula (a2), and the aforementioned alicyclic tetracarboxylic dianhydride ( Composed of other alicyclic tetracarboxylic dianhydrides (A1-2) other than A1-1), (In formula (a2), R ^a11 , R ^a12 and R ^a13 are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and a fluorine atom, and a is 0 or more An integer of 12 or less) The ratio of the mass of the aforementioned other alicyclic tetracarboxylic dianhydride (A1-2) to the number of moles of the aforementioned tetracarboxylic dianhydride (A1) is 0.1 mol% or more and 6 mol% the following. The coating composition according to claim 1, wherein the other alicyclic tetracarboxylic dianhydride (A1-2) is a compound represented by the following formula (a2-1) or the following formula (a2-2), (In formula (a2-1), R ^a21 , R ^a22 , R ^a23 and R ^a24 are each independently a hydrogen atom, an alkyl group with 1 to 5 carbon atoms, or an alkenyl group with 2 to 5 carbon atoms, R ^a21 or R ^a22 , and R ^a23 or R ^a24 can be bonded to each other to form methylene, ethylidene, propane-2,2-diyl, ethylene-1,2-diyl, in formula (a2-2) , R ^a25 , R ^a26 , R ^a27 , R ^a28 , R ^a29 , R ^a30 , R ^a31 and R ^a32 are each independently a hydrogen atom, an alkyl group with 1 to 5 carbon atoms, or an alkene with 2 to 5 carbon atoms The base, R ^a25 or R ^a26 , and R ^a27 or R ^a28 can be bonded to each other to form methylene, ethylene, propane-2,2-diyl, ethylene-1,2-diyl, R ^a29 or R ^a30 , and R ^a31 or R ^a32 may be bonded to each other to form methylene, ethylidene, propane-2,2-diyl, ethylene-1,2-diyl). The coating composition according to claim 1 or 2, wherein the aromatic diamine compound (A2) is one or more compounds selected from the following formulas (21) to (24), (In the formulas (21) to (24), ^R111 represents a group consisting of a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group with 1 to 4 carbon atoms, and a halogenated alkyl group with 1 to 4 carbon atoms. One of the group, in formula (24), Q represents 9,9'-fenylene, or is selected from the formula: -C ₆ H ₄ -, -CONH-C ₆ H ₄ -NHCO-, -NHCO- C ₆ H ₄ -CONH-, -OC ₆ H ₄ -CO-C ₆ H ₄ -O-, -OCO-C ₆ H ₄ -COO-, -OCO-C ₆ H ₄ -C ₆ H ₄ -COO- , -OCO-, -O-, -S-, -CO-, -CONH-, -SO ₂ -, -C(CF ₃ ) ₂ -, -C(CH ₃ ) ₂ -, -CH ₂ -, - OC ₆ H ₄ -C(CH ₃ ) ₂ -C ₆ H ₄ -O-, -OC ₆ H ₄ -C(CF ₃ ) ₂ -C ₆ H ₄ -O-, -OC ₆ H ₄ -SO ₂ - C ₆ H ₄ -O-, -C(CH ₃ ) ₂ -C ₆ H ₄ -C(CH ₃ ) ₂ -, -OC ₁₀ H ₆ -O-, -OC ₆ H ₄ -C ₆ H ₄ -O - and -OC ₆ H ₄ -O- is one of the group consisting of groups represented by -C ₆ H ₄ - is phenylene, -C ₁₀ H ₆ - is naphthalenediyl). The coating composition according to claim 3, wherein the aforementioned aromatic diamine compound (A2) contains a compound represented by the aforementioned formula (24). The coating composition according to claim 4, wherein the aforementioned aromatic diamine compound (A2) is represented by the aforementioned formula (24), and the aforementioned Q is a compound of -CONH-. A method for producing a paint composition, which comprises polymerizing tetracarboxylic dianhydride (A1) and aromatic diamine compound (A2) in a solvent (S) to generate polyamic acid (A), or to make tetracarboxylic dianhydride (A1) Carboxylic acid dianhydride (A1) and the aforementioned aromatic diamine compound (A2) are polymerized to form the aforementioned polyamic acid (A), and the isolated aforementioned polyamic acid (A) is mixed with the solvent (S) A method for producing a coating composition characterized in that the aforementioned tetracarboxylic dianhydride (A1) is only an alicyclic tetracarboxylic dianhydride (A1-1) of a compound represented by the following formula (a2), and the aforementioned alicyclic Composed of other alicyclic tetracarboxylic dianhydrides (A1-2) other than tetracarboxylic dianhydrides (A1-1), (In formula (a2), R ^a11 , R ^a12 and R ^a13 are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and a fluorine atom, and a is 0 or more An integer of 12 or less) The ratio of the mass of the aforementioned other alicyclic tetracarboxylic dianhydride (A1-2) to the number of moles of the aforementioned tetracarboxylic dianhydride (A1) is 0.1 mol% or more and 6 mol% the following. A method for producing a polyimide resin, comprising a step of forming the aforementioned coating composition according to any one of claims 1 to 5, and An imidization step of heating the shaped coating composition to imidize it.