Composition and metal insulating cover material

Abstract

To provide a composition with enhanced heat resistance, bending durability, electrical insulation, wear resistance, processability, and adhesion.SOLUTION: A composition includes a solvent, a compound represented by Formula (0) and / or Formula (0'), and a compound including a functional group that reacts with a terminally cyclized product thereof.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a composition having high insulation properties, high heat resistance, flexibility and abrasion resistance, as well as excellent processability and adhesion, a metal insulating coating material using the composition, and a method for producing the same. [Background technology]

[0002] 2. Description of the Related Art Polyimides, which are excellent in heat resistance, electrical insulation properties, abrasion resistance, chemical resistance, mechanical properties, and the like, have been widely used in the fields of electrical and electronic parts, transportation equipment, spacecraft, aircraft, and the like. In insulating coatings, a typical application of polyimide, higher performance is required of insulating resins as the performance of final products becomes higher.

[0003] For example, insulating coating materials for the various electric wires used in automobiles require high heat resistance to accompany the increasing power output of automobiles, as well as high flexibility and mechanical strength to accommodate the increased bending of electric wires and the friction between the electric wires that accompanies higher wiring density.

[0004] On the other hand, flexible printed circuits (FPCs) require high flexibility to fit into the device housing as devices become smaller. For this reason, the insulating coating must have the mechanical strength to achieve sufficient durability and flexibility to prevent breakage when bent. Furthermore, FPCs go through a solder reflow process when mounting electronic components, so they must also be heat resistant to the heat of the solder reflow process.

[0005] If the molecular weight of polyimide is increased to meet these demands for higher performance, the viscosity of the polyimide solution used to form the insulating coating increases, causing problems such as uneven coating thickness and residual solvent in the coating. If the polyimide concentration is reduced to achieve a viscosity that provides excellent coatability, a thick film cannot be obtained in a single coating. To increase the film thickness, multiple coatings are required, reducing productivity.

[0006] In response to these issues, development is being conducted to reduce the viscosity while maintaining the mechanical properties by adding isocyanate to a polyimide resin solution (Patent Document 1).In addition, enameled wires are being developed that use polyimide resin, which has better heat resistance than polyamide-imide resin, as a coating material (Patent Document 2). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 9-137118 [Patent Document 2] JP 2011-29100 A

[0008] In Patent Document 1, when isocyanate reacts with something other than an acid anhydride, a bond other than an imide bond is formed, which reduces the rigidity of the molecular chain and decreases the mechanical properties. In Patent Document 2, the heat resistance of polyimide resins is usually improved by making the molecular skeleton a rigid structure. Therefore, the rigidification of the molecular skeleton increases the abrasion resistance (resulting in a high elastic modulus), but on the other hand, it causes a decrease in molecular mobility and flexibility, resulting in poor bending resistance. Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to provide a composition which has excellent electrical insulation properties, as well as high heat resistance, flexibility, abrasion resistance, processability and adhesion, and a metal insulating coating material which uses said composition. [Means for solving the problem]

[0010] The present inventors have found that by using a polyimide resin and / or a precursor thereof (hereinafter, the polyimide resin and / or the precursor thereof may be collectively referred to as "polyimide resins") containing a compound represented by the following formula (0) and / or a compound represented by the following formula (0'), and a compound having a functional group that reacts with a terminal ring-closed product of the compound represented by the following formula (0) and / or the compound represented by the following formula (0'), an insulating composition having excellent processability and adhesion while maintaining heat resistance, flex resistance, and abrasion resistance can be obtained, and have arrived at the present invention.

[0011] The present invention relates to the following items [1] to

[11] .

[0012] [1] A composition comprising a solvent and a polyimide resin precursor and / or a polyimide resin, the polyimide resin precursor and / or the polyimide resin comprising a compound represented by the following formula (0) and / or a compound represented by the following formula (0'), and a compound having a functional group that reacts with a terminal cyclic product of the compound represented by the following formula (0) and / or the compound represented by the following formula (0'):

[0013] [ka]

[0014] In the above formula (0) and formula (0'), R' each independently represents a hydrogen atom or an alkyl group. a R represents a tetracarboxylic acid residue. b R represents a diamine residue. a and / or R b In the formula, p and q each represent an arbitrary integer, and p and q each represent an arbitrary integer, and / or 1 to 4 substituents each having an active hydrogen atom.

[0015] [2] The composition described in [1], wherein the boiling point of the solvent is 120°C or higher.

[0016] [3] The composition according to [1] or [2], wherein the concentration of the polyimide resin precursor and / or the polyimide resin in the composition is 15% by weight or more and 40% by weight or less.

[0017] [4] The composition according to any one of [1] to [3], wherein the polyimide resin precursor and / or the polyimide resin has at least one of a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2):

[0018] [ka]

[0019] [5] The composition according to any one of [1] to [4], wherein the polyimide resin precursor and / or the polyimide resin has a structural unit represented by the following formula (3):

[0020] [ka]

[0021] In the above formula (3), R 1 ~R 8 may be the same or different and are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, or a hydroxyl group. X is a direct bond, an oxygen atom, a sulfur atom, an alkylene group having 1 to 4 carbon atoms, a sulfonyl group, a sulfinyl group, a sulfide group, a carbonyl group, an amide group, an ester group, or a secondary amino group. n is an integer of 0 to 4.

[0022] [6] The linking group having an active hydrogen or the substituent having an active hydrogen is -NH-, ═NH, -C(O)NH-, -NHC(O)O-, -NHC(O)NH-, -NHC(S)NH-, -NH 2 The composition according to any one of [1] to [5], wherein the structure is selected from the group consisting of -OH, -C(O)OH, -SH, -C(O)N(OH)- and -C(O)SH.

[0023] [7] The composition according to [6], wherein the linking group having an active hydrogen or the substituent having an active hydrogen has a structure selected from the group consisting of -C(O)NH-, -NHC(O)NH- and -OH.

[0024] [8] The composition according to any one of [1] to [7], wherein a fired film of the composition has a glass transition temperature (Tg) of 250° C. or higher and 400° C. or lower.

[0025] [9] The composition according to any one of [1] to [8], wherein the viscosity of the composition is 10,000 cP or less.

[0026]

[10] A metal insulating coating material having a resin layer made of the composition according to any one of [1] to [9].

[0027]

[11] A method for producing a metal insulating coating material, comprising a step of coating a metal with the composition according to any one of [1] to [9].

[0028] The present invention also relates to the following <1> ~ <8> The gist of this paper is as follows.

[0029] <1> A composition comprising a solvent, a polyimide resin precursor and / or a polyimide resin, the polyimide resin precursor and / or polyimide resin comprises a compound represented by the following formula (0) and / or a compound represented by the following formula (0'), and a compound having a functional group that reacts with a terminal ring-closed product of the compound represented by the following formula (0) and / or the compound represented by the following formula (0'), the concentration of the polyimide resin precursor and / or polyimide resin in the composition is 15% by weight or more and less than 30% by weight, and the viscosity of the composition is 10,000 cP or less.

[0030] [ka]

[0031] In the above formula (0) and formula (0'), R' each independently represents a hydrogen atom or an alkyl group.a R represents a tetracarboxylic acid residue. b represents a diamine residue, and p and q each represent any integer.

[0032] <2> The polyimide resin precursor and / or the polyimide resin has at least one of a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2): <1> The insulating coating resin composition according to claim 1 .

[0033] [ka]

[0034] <3> The glass transition temperature (Tg) of the fired film of the polyimide resin precursor and / or the polyimide resin is 250° C. or higher and 400° C. or lower. <1> or <2> The resin composition for insulating coating material according to claim 1.

[0035] <4> The polyimide resin precursor and / or polyimide resin has a structural unit represented by the following formula (3): <1> ~ <3> The resin composition for insulating coating material according to any one of claims 1 to 4.

[0036] [ka]

[0037] In the above formula (3), R 1 ~R 8 may be the same or different and are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, or a hydroxyl group. X is a direct bond, an oxygen atom, a sulfur atom, an alkylene group having 1 to 4 carbon atoms, a sulfonyl group, a sulfinyl group, a sulfide group, a carbonyl group, an amide group, an ester group, or a secondary amino group. n is an integer of 0 to 4.

[0038] <5> The polyimide resin precursor and / or the polyimide resin is selected from the group consisting of -NH-, ═NH, -C(O)NH-, -NHC(O)O-, -NHC(O)NH-, -NHC(S)NH-, -NH 2 -OH, -C(O)OH, -SH, -C(O)N(OH)-, -(O)S(O)-, -C(O)-, and -C(O)SH; <1> ~ <4> The resin composition for insulating coating material according to any one of claims 1 to 4.

[0039] <6> the polyimide resin precursor and / or the polyimide resin has a repeating unit containing a -C(O)NH- structure; <5> The resin composition for insulating coating material according to claim 1.

[0040] <7> The -C(O)NH- structure is a structure derived from 4,4'-diaminobenzanilide. <6> The resin composition for insulating coating material according to claim 1.

[0041] <8> <1> ~ <7> 2. A metal coating material having at least a resin layer comprising the resin composition for insulating coating material according to claim 1. Effect of the Invention

[0042] According to the present invention, there are provided a composition which has high insulation properties, high heat resistance, flexibility and abrasion resistance, and further has excellent processability and adhesion, and a metal insulating coating material using said composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] The following is a detailed description of an embodiment of the present invention. The following description is an example of an embodiment of the present invention, and the present invention is not limited to the following description as long as it does not deviate from the gist of the present invention. In this specification, when the expression "~" is used, it is used as an expression including the numerical values ​​or physical property values ​​before and after it.

[0044] [Composition] The composition of the present invention is a composition containing a solvent and a polyimide resin precursor and / or a polyimide resin, and is characterized in that the polyimide resin precursor and / or the polyimide resin contains a compound represented by the following formula (0) and / or a compound represented by the following formula (0') (hereinafter, these may be referred to as "compounds (0) and (0')"), and a compound having a functional group that reacts with a terminal cyclic product of the compound represented by the following formula (0) and / or the compound represented by the following formula (0').

[0045] [ka]

[0046] In the above formula (0) and formula (0'), Each R' independently represents a hydrogen atom or an alkyl group. R a represents a tetracarboxylic acid residue. R b represents a diamine residue. R a and / or R b It has one linking group having active hydrogen and / or 1 to 4 substituents having active hydrogen. p and q each represent any integer.

[0047] In the following, the term "polyimide resin coating" refers to a polyimide coating obtained by baking the composition of the present invention.

[0048] [Mechanism of action] The reason why the insulating coating material obtained from the composition of the present invention has improved processability and adhesion while maintaining heat resistance and mechanical properties is not clear, but is presumed to be as follows.

[0049] During baking of the coating film of the composition of the present invention, water and / or alcohol are eliminated from the ring-opened tetracarboxylic acid terminal of compound (0) or (0'), and the ring-closed acid anhydride reacts with a functional group (reactive group) that reacts with the acid anhydride in the composition to form a polymer. Therefore, although the composition has a low viscosity, the coating film after baking becomes a polymer, and it is presumed that the heat resistance and mechanical properties are good. In the case of the polyimide resin precursor, not only the reactive groups present in the composition but also an exchange reaction occurs during baking, and the cleaved molecules react partially with compound (0) or (0'). In addition, since the composition has a low viscosity, it is possible to process it at a high concentration, and it is considered that the coatability is good.

[0050] Also, R a and / or R b By having one linking group having active hydrogen and / or one to four substituents having active hydrogen, the polymer has an appropriate elastic modulus due to intermolecular interactions, and can achieve both abrasion resistance and bending resistance.

[0051] Furthermore, when the polymer has many polar groups, such as functional groups having active hydrogen in the molecular chain, it can interact with electrically charged substrates, particularly metals, and improve adhesion to conductors.

[0052] [Polyimide resins] <expression(0),(0')> The polyimide resin according to the present invention contains a compound represented by the following formula (0) and / or a compound represented by the following formula (0').

[0053] [ka]

[0054] In the above formula (0) and formula (0'), Each R' independently represents a hydrogen atom or an alkyl group. R a represents a tetracarboxylic acid residue. R b represents a diamine residue. Ra and / or R b It has one linking group having active hydrogen and / or 1 to 4 substituents having active hydrogen. p and q each represent any integer.

[0055] (R') Each R' independently represents a hydrogen atom or an alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 10 or less, more preferably 5 or less, and even more preferably 2 or less. When the number of carbon atoms is less than the above upper limit, alcohol tends to be easily eliminated and vaporized by closing the ring at the end during baking. The alkyl group may be linear or branched, or may form a ring. The alkyl group may have a substituent. Each R' in formula (0) and (0') may be the same or different.

[0056] (p, q) p and q each represent an arbitrary integer. Although not particularly limited, the range can be, for example, the number of repetitions of each formula corresponding to the suitable weight average molecular weight (Mw) of the polyimide resin precursor and polyimide resin described below.

[0057] (Linking group having active hydrogen / Substituent having active hydrogen) R a and / or R b It has one linking group having active hydrogen and / or 1 to 4 substituents having active hydrogen.

[0058] In the present invention, the linking group or substituent having an active hydrogen refers to a group containing a hydrogen atom bonded to O, N, or S, which has a high electronegativity, and which can form a hydrogen bond between identical structures.

[0059] In the repeating units of formulas (0) and (0'), R in at least one repeating unit a and / or R bHowever, it is sufficient for each repeating unit to have one linking group having an active hydrogen and / or from 1 to 4 substituents having active hydrogen, and all repeating units may have one linking group having an active hydrogen and / or from 1 to 4 substituents having active hydrogen.

[0060] It is generally known that the elastic modulus increases when molecular chains are linked by chemical bonds. Chemical bonds can be covalent or non-covalent, and when molecular chains are linked by covalent bonds, the elastic modulus increases (i.e., wear resistance improves), but mechanical flexibility (elongation) decreases. In other words, bending resistance decreases. Normally, when polyimide resins are baked at a certain temperature or higher, the ends of the molecules react with other molecules or specific sites within the molecules to form covalent bonds, reducing their flexibility. However, when the molecules have repeating units that include a structure that forms non-covalent bonds, non-covalent bonds (hereinafter sometimes simply referred to as "non-covalent bonds") are formed between molecules and / or with specific sites within the molecules, and the intermolecular interactions provide a moderate elastic modulus, allowing both wear resistance and bending resistance to be achieved.

[0061] Examples of non-covalent bonds include ionic bonds, π-π stacking, and hydrogen bonds. Hydrogen bonds are preferred because they increase the heat resistance of the polyimide resin coating and also provide excellent mechanical properties. In the present invention, the above-mentioned linking group and / or substituent having active hydrogen, which is particularly effective in forming hydrogen bonds, is used as the structure for forming hydrogen bonds. a and / or R b Introduce it into.

[0062] The linking group having active hydrogen and the substituent having active hydrogen are not particularly limited, and only the linking group having active hydrogen or the substituent having active hydrogen may be used, or these may be used in combination. In particular, since the twist of the molecular chain is small, the interaction between molecules becomes large, and the heat resistance and elastic modulus tend to be improved, it is preferable to have a linking group having active hydrogen, and more preferably to have only a linking group having active hydrogen.

[0063] R a and / or Rb If R has two or more linking groups having active hydrogen, the intermolecular interaction becomes strong and the bending resistance tends to be poor. a and / or R b There is one linking group having an active hydrogen atom in the compound. Also, R a and / or R b The number of substituents having active hydrogen in the monomer is from 1 to 4, but is preferably 1 or 2 in order to obtain an appropriate relationship for the twisting of the molecular chain. The electronegativity of the substituents having active hydrogen depends on the size of the substituent and the distance between the substituents, and when the electronegativity is large and the substituents are far apart, it is preferable to have a large number of substituents.

[0064] The linking group having an active hydrogen atom and / or the substituent having an active hydrogen atom are R a and / or R b However, from the viewpoints of ease of polymerization and manufacturing stability, b In addition, it is preferable that R of the linking group and / or the substituent is a and / or R b The linking or substituting position within is not particularly limited.

[0065] Specific examples of linking groups having active hydrogen and substituents having active hydrogen include -NH- (imino bond; also referred to as imino group), =NH (imino group), -C(O)NH- (amide bond; also referred to as amide group), -NHC(O)O- (urethane bond; also referred to as urethane group), -NHC(O)NH- (urea bond; also referred to as urea group), -NHC(S)NH- (thiourea bond; also referred to as thiourea group), -NH 2 (amino group), -OH (hydroxyl group), -C(O)OH (carboxy group), -SH (thiol group), -C(O)N(OH)- (hydroxyamide group), -SH (thiol group), -C(O)N(OH)- (hydroxyamide group), -C(O)SH (thiocarboxy group), etc. The above-mentioned linking groups having active hydrogen and substituents having active hydrogen are preferred from the viewpoints of heat resistance, abrasion resistance, and bending resistance in particular.

[0066] Among the above-mentioned linking groups having active hydrogen and substituents having active hydrogen, -C(O)NH- (amide bond), -NHC(O)NH- (urea bond) and -OH (hydroxyl group) are particularly preferred, with -C(O)NH- (amide bond) being particularly preferred from the viewpoint of the above-mentioned excellent introduction effect.

[0067] The content of the linking group having active hydrogen and the content of the substituent having active hydrogen in the polyimide resin molecule are not particularly limited, but are preferably as follows.

[0068] In the case of a polyimide resin precursor, assuming that all repeating units in the polyimide resin precursor contain one linking group having active hydrogen or one substituent having active hydrogen as 100%, the proportion is usually greater than 0%, preferably 1% or more, more preferably 2% or more, and even more preferably 5% or more, and is preferably less than 200%, more preferably 100% or less, and even more preferably 50% or less. In the case of polyimide resins, assuming that the case in which all repeating units contain one linking group having active hydrogen or one substituent having active hydrogen is 100%, the percentage is usually greater than 0%, preferably 1% or more, more preferably 2% or more, and even more preferably 5% or more, and is preferably less than 200%, more preferably 100% or less, and even more preferably 50% or less. When the content of the linking group having active hydrogen or the substituent having active hydrogen is within the above range, a polyimide resin coating having better mechanical properties such as tensile modulus and elongation can be obtained.

[0069] The content of the linking group having active hydrogen or the substituent having active hydrogen in the molecule of the polyimide resin can usually be determined by NMR, IR, Raman, titration, mass spectrometry or the like.

[0070] A linking group having an active hydrogen atom or a substituent having an active hydrogen atom is R a and / or R bExamples of the method for introducing hydrogen into the polyimide resin include a method for polymerizing a monomer having one linking group having active hydrogen and / or from 1 to 4 substituents having active hydrogen (hereinafter sometimes referred to as a "hydrogen bond-forming monomer") when producing a polyimide resin, and a method for forming one linking group having active hydrogen and / or from 1 to 4 substituents having active hydrogen by a polymerization reaction. In particular, a method for polymerizing a hydrogen bond-forming monomer using the hydrogen bond-forming monomer as a raw material for producing a polyimide resin is preferred.

[0071] Examples of the hydrogen bond forming monomer include tetracarboxylic dianhydrides and diamine compounds having one linking group having active hydrogen and / or 1 to 4 substituents having active hydrogen.

[0072] Specifically, examples of the diamine compound include 4,4'-diaminobenzanilide, 4,4'-bis(4-aminobenzamide)-3,3'-dihydroxybiphenyl, 2,2'-bis(3-amino-4-hydroxyphenyl)sulfone, 2,2'-bis(3-amino-4-hydroxyphenyl)propane, 4,4'-diamino-3,3'-dihydroxybiphenyl(3,3'-dihydroxybenzidine), bis(4-amino-3-carboxyphenyl)methane, etc. These hydrogen bond forming monomers may be used alone or in any combination and ratio. Among these, it is particularly preferable to use 4,4'-diaminobenzanilide, since it has an excellent introduction effect.

[0073] The amount of these hydrogen bond-forming monomers to be introduced is not particularly limited, but is preferably as follows. In the case of a polyimide resin precursor, the amount of the aryl group is preferably 0.5 mol % or more, more preferably 5 mol % or more, and even more preferably 10 mol % or more of all repeating units of the polyimide resin precursor, and is preferably 50 mol % or less, more preferably 40 mol % or less, and even more preferably 35 mol % or less of all repeating units of the polyimide resin precursor. In the case of a polyimide resin, the content of the aryl group is preferably 0.5 mol % or more, more preferably 5 mol % or more, and even more preferably 10 mol % or more of all repeating units of the polyimide resin, and is preferably 50 mol % or less, preferably 40 mol % or less, and even more preferably 35 mol % or less of all repeating units of the polyimide resin. When the amount of hydrogen bond-forming monomer introduced into the polyimide resin precursor and the polyimide resin is within the above range, a polyimide resin coating that has both high elasticity and high elongation tends to be obtained. Hereinafter, the amount of hydrogen bond-forming monomer introduced into all repeating units is referred to as the "amount of hydrogen bond-forming monomer introduced."

[0074] (R a ) R in formulas (0) and (0') a represents a structure derived from a tetracarboxylic dianhydride, and each R in formula (0) and (0') a may be the same or different.

[0075] R a Examples of the tetracarboxylic dianhydride constituting the copolymer include linear aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides, etc. These compounds may be used alone or in any combination of two or more kinds in any ratio.

[0076] Examples of the chain aliphatic tetracarboxylic dianhydride include ethylene tetracarboxylic dianhydride, butane tetracarboxylic dianhydride, and meso-butane-1,2,3,4-tetracarboxylic dianhydride.

[0077] Examples of the alicyclic tetracarboxylic dianhydride include 3,3',4,4'-biscyclohexanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-11,2-dicarboxylic anhydride, tricyclo[6.4.0.0]dianhydride, and the like. 2,7 ]dodecane-1,8:2,7-tetracarboxylic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, 1,1'-bicyclohexane-3,3',4,4'-tetracarboxylic dianhydride, and the like.

[0078] Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 4,4'-(p-phenylenedioxy)diphthalic dianhydride, 4,4-(m ... oxy)diphthalic dianhydride, 2,2',6,6'-biphenyltetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2'-bis(trifluoromethyl)-4,4',5,5'-biphenyltetracarboxylic dianhydride, 4,4'-(hexafluorotrimethylene)-diphthalic Acid dianhydrides, 4,4'-(octafluorotetramethylene)-diphthalic dianhydride, 4,4'-oxydiphthalic anhydride, 1,2,5,6-naphthalenedicarboxylic dianhydride, 1,4,5,8-naphthalenedicarboxylic dianhydride, 2,3,6,7-naphthalenedicarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, and the like.

[0079] (R b ) R in formulas (0) and (0') b represents a structure derived from a diamine compound, and each R in formula (0) and (0')b may be the same or different.

[0080] R b Examples of the diamine compound constituting the copolymer include aromatic diamine compounds, chain aliphatic diamine compounds, alicyclic diamine compounds, etc. These compounds may be used alone or in any combination of two or more kinds in any ratio.

[0081] Examples of the aromatic diamine compound include 1,4-phenylenediamine, 1,2-phenylenediamine, 1,3-phenylenediamine, 4,4'-(biphenyl-2,5-diylbisoxy)bisaniline, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, bis(4-(4-aminophenoxy) phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, 1,3-bis(4-aminophenoxy)neopentane, 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diamino-2,2'-dimethylbiphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-diamino-3,3'-dihydroxybiphenyl, bis(4-amino-3-carboxyphenyl)methane, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone , 4,4'-diaminodiphenyl sulfide, N-(4-aminophenoxy)-4-aminobenzamine, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, bis(3-aminophenyl)sulfone, norbornanediamine, 4,4'-diamino-2-(trifluoromethyl)diphenyl ether, 5-trifluoromethyl-1,3-benzenediamine, 2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane, 4,4'-diamino-2,2'-bis (trifluoromethyl)biphenyl, 2,2-bis[4-{4-amino-2-(trifluoromethyl)phenoxy}phenyl]hexafluoropropane, 2-trifluoromethyl-p-phenylenediamine, 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane, 4,4'-(9-fluorenylidene)dianiline, 2,7-diaminofluorene, 1,5-diaminonaphthalene, and 3,7-diamino-2,8-dimethyldibenzothiophene 5,5-dioxide.

[0082] Examples of the chain aliphatic diamine compound include 1,2-ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-hexamethylenediamine, 1,5-diaminopentane, 1,10-diaminodecane, 1,2-diamino-2-methylpropane, 2,3-diamino-2,3-butanediamine, and 2-methyl-1,5-diaminopentane.

[0083] Examples of the alicyclic diamine compound include 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), and 4,4'-methylenebis(2-methylcyclohexylamine).

[0084] Of the polyimide resins contained in the composition of the present invention, the amount of compounds (0) and (0') is preferably 10% by weight or more, more preferably 20% by weight or more, and particularly preferably 30% by weight or more. Also, it is preferably 90% by weight or less, more preferably 80% by weight or less, and particularly preferably 70% by weight or less. When the amount of compounds (0) and (0') is within the above range, the polyimide resin molecules tend to elongate, and a coating film having excellent heat resistance and mechanical properties tends to be obtained.

[0085] <Compounds having functional groups capable of reacting with the terminal ring-closed products of compounds (0) and (0')> The polyimide resins according to the present invention contain a compound having a functional group reactive with the terminal cyclic product of the compounds (0) and (0') (hereinafter, sometimes referred to as "a compound having a functional group reactive with the terminal cyclic product").

[0086] The functional group that reacts with the terminal ring-closed product of compound (0) or (0') is not particularly limited, and examples thereof include an amino group, an isocyanate group, a hydroxyl group, a thiol group, a glycidyl group, etc. In particular, an amino group and an isocyanate group are preferred in terms of heat resistance and mechanical properties, since they form an imide bond after baking and molding.

[0087] The compound having a functional group that reacts with the terminal ring-closed product is not particularly limited as long as it has the functional group, and examples of the compound include polyvalent compounds.

[0088] Of the polyimide resins contained in the composition of the present invention, the amount of the compound having a functional group that reacts with the closed-end ring product is preferably 10% by weight or more, more preferably 20% by weight or more, and particularly preferably 30% by weight or more. Also, it is preferably 90% by weight or less, more preferably 80% by weight or less, and particularly preferably 70% by weight or less. When the amount of the compound having a functional group that reacts with the closed-end ring product is within the above range, the polyimide resin molecules tend to elongate, and a coating film with excellent heat resistance and mechanical properties tends to be obtained.

[0089] In the polyimide resins according to the present invention, the content ratio of the compounds (0), (0') and the compound having a functional group reactive with a closed-chain terminal product is not particularly limited. However, from the viewpoint of molecular weight elongation, it is preferable that the compound having a functional group reactive with a closed-chain terminal product and the compounds (0) and (0') are present in approximately equal amounts, since this makes it difficult for molecular cleavage to occur due to an exchange reaction.

[0090] (Compounds having an amino group) As the compound having a functional group that reacts with the terminal ring-closed product, a compound having an amino group is preferable, and in particular, a compound having an amine terminal structure (amine-terminated compound) is preferable. The amine-terminated compound is a polyimide resin, and both terminal structures are amines.

[0091] The structure of the amine-terminated compound is not particularly limited, but examples thereof include structures represented by the following formulas (5) and (6).

[0092] [ka]

[0093] In the above formula (5) and formula (6), R c represents a tetracarboxylic acid residue, R d represents a diamine residue. Each of t and u represents an arbitrary integer.

[0094] (t, u) Each of t and u represents an arbitrary integer. Although there is no particular limitation, the range can be, for example, the number of repetitions of each formula when it corresponds to a suitable weight average molecular weight (Mw) of polyimide resins described later.

[0095] (R c ) R in Equations (5) and (6) c represents a structure derived from a tetracarboxylic dianhydride, and each R in formulas (5) and (6) c may be the same or different. Specifically, each R in the above formulas (0) and (0′) a The preferred ranges are also the same. a and R c may be the same or different.

[0096] (R d ) R in Equations (5) and (6) d represents a structure derived from a diamine compound, and each R in formulas (5) and (6) d may be the same or different. Specifically, each R in the above formulas (0) and (0′) b The preferred ranges are also the same. b and R d may be the same or different.

[0097] R c ,R d R in (0),(0') a ,R b When R in at least one repeating unit in the above formulas (5) and (6) is the same as R c and / or R d However, it is sufficient that each repeating unit has one linking group having an active hydrogen and / or from 1 to 4 substituents having active hydrogen, and all repeating units may have one linking group having an active hydrogen and / or from 1 to 4 substituents having active hydrogen.

[0098] <Other polyimide resins> The composition of the present invention may contain polyimide resins having other structures in addition to the compounds (0) and (0') and the compounds having functional groups reactive with the terminal ring-closed products. The polyimide resins having other structures are not particularly limited, but examples thereof include compounds represented by the following formulas (a) and (b).

[0099] [ka]

[0100] In the above formulas (a) and (b), R a ,R b is R in formulas (0) and (0'). a ,R b is synonymous with. Each of r and s represents an arbitrary integer and has the same meaning as p and q in formulas (0) and (0').

[0101] In the repeating units in the above formulas (a) and (b), R in at least one repeating unit a and / or R b However, it is sufficient that each repeating unit has one linking group having an active hydrogen and / or from 1 to 4 substituents having active hydrogen, and all repeating units may have one linking group having an active hydrogen and / or from 1 to 4 substituents having active hydrogen.

[0102] <Other ingredients> In producing polyimide resins, compounds having ethynyl groups, vinyl groups, allyl groups, cyano groups, isocyanate groups, etc. that serve as crosslinking points (hereinafter sometimes referred to as "other monomers") may be used depending on the purpose.

[0103] From the viewpoint of heat resistance and productivity, the polyimide resins used in the present invention preferably have at least one of a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2). In particular, the structural units represented by the following formulas (1) and (2) are preferably present in formulas (0), (0'), (a) and (b). By including the structural units represented by the following formulas (1) and (2), both the reactivity during polymerization and the solubility of the polyimide resins in solvents become good, and a polyimide resin coating having a rigid skeleton and excellent heat resistance can be obtained.

[0104] [ka]

[0105] The structural units represented by the above formulae (1) and (2) may be derived from a tetracarboxylic dianhydride or a diamine compound, but are usually introduced into polyimide resins by a tetracarboxylic dianhydride. Therefore, the polyimide resins used in the present invention are preferably produced using at least pyromellitic dianhydride and / or 3,3',4,4'-biphenyltetracarboxylic dianhydride as the raw material tetracarboxylic dianhydride.

[0106] Moreover, the polyimide resin used in the present invention preferably has a structural unit represented by the following formula (3) from the viewpoints of improving heat resistance and productivity.

[0107] [ka]

[0108] In the above formula (3), R 1 ~R 8 may be the same or different and are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, or a hydroxyl group. Among these, a hydrogen atom or a methyl group is preferred because it improves both the reactivity during polymerization and the solubility of polyimide resins in solvents.

[0109] In the above formula (3), X is a direct bond, an oxygen atom, a sulfur atom, an alkylene group having from 1 to 4 carbon atoms, a sulfonyl group, a sulfinyl group, a sulfide group, a carbonyl group, an amide group, an ester group, or a secondary amino group. Among these, a direct bond, an oxygen atom, a sulfur atom, an alkylene group having from 1 to 4 carbon atoms, a sulfonyl group, or an amide group is preferred, with an oxygen atom being particularly preferred, because the polyimide resin coating obtained by heating and baking has good mechanical properties and heat resistance.

[0110] In the above formula (3), n is an integer of 0 to 4. n is preferably an integer of 1 to 4.

[0111] In the structural unit represented by formula (3) in the entire molecule of polyimide resin, R 1 ~R 8 , X, and n do not necessarily have to all be the same. In particular, when n is an integer of 2 or more, X may have a different structure.

[0112] Among the structural units represented by formula (3), those represented by any of the structural units represented by the following formulae (3-1) to (3-6) are preferred because they provide a polyimide resin coating obtained by heating and baking with good mechanical properties and heat resistance. One molecule of polyimide resins may contain only one type of these structural units, or a combination of multiple types.

[0113] [ka]

[0114] The structural unit represented by the above formula (3) may be derived from a tetracarboxylic dianhydride or a diamine compound, but is usually introduced into polyimide resins by a diamine compound.

[0115] Therefore, the polyimide resins used in the present invention are preferably produced using at least a diamine compound represented by the following formula (4) as the diamine compound.

[0116] [ka]

[0117] In the above formula (4), R 1 '~R 8 ' is R in formula (3) 1 ~R 8 X' is synonymous with X. n' is synonymous with n.

[0118] Examples of the diamine compound represented by the above formula (4) include 4,4'-diaminodiphenyl ether, 2,2'-dimethyl-4,4'-diaminobiphenyl, 1,4-bis(4-aminophenoxy)benzene, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-bis(4-aminophenoxy)biphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 4,4'-diaminobenzoylanilide, 4-aminophenyl-4-aminobenzoate, bis(4-aminophenyl)terephthalate, bis(4-(4-aminophenoxy)phenyl)sulfone, and bis(4-amino-3-carboxyphenyl)methane. Among these, 4,4'-diaminodiphenyl ether, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, and the like are preferable.

[0119] The polyimide resins used in the present invention may have structural units other than the structural unit represented by the formula (1) or (2) and the structural unit represented by the formula (3). However, in order to effectively obtain the above-mentioned effects due to the structural unit represented by the formula (1) or (2) and the structural unit represented by the formula (3), it is preferable that the structural units represented by the formula (1) and / or (2) account for 80 mol % or more, particularly 90 to 100 mol %, of all structural units derived from the tetracarboxylic dianhydride constituting the polyimide resin, and that the structural units represented by the formula (3) account for 80 mol % or more, particularly 90 to 100 mol %, of all structural units derived from the diamine compound constituting the polyimide resin.

[0120] <Manufacturing method> There is no particular limitation on the method for producing polyimide resins, and a conventionally known imidization method can be used. For example, a method of performing an imidization reaction of the above-mentioned tetracarboxylic dianhydride and diamine compound by heating and dehydration or a dehydration reagent in the presence of a reaction solvent, a method of obtaining a polyimide resin precursor by amidation reaction of the tetracarboxylic dianhydride and diamine compound in the presence of a reaction solvent, and then performing an imidization reaction of the precursor by heating and dehydration or a dehydration reagent, etc. can be mentioned. By having a necessary amount of the above-mentioned hydrogen bond forming monomer present in this reaction system, an insulating coating material having a repeating unit containing a hydrogen bond forming structure can be produced. Furthermore, the above-mentioned other monomers may be present in this reaction system to perform the reaction. Furthermore, the compounds (0) and (0') and the compound having a functional group reactive with the terminal ring-closed product may be produced simultaneously in the reaction system, or may be produced separately and then mixed. By the reaction in the presence of a reaction solvent, a polyimide resin is obtained as a polyimide resin composition.

[0121] Hereinafter, the tetracarboxylic dianhydride, the diamine compound, the hydrogen bond-forming monomer, and other monomers are collectively referred to as "raw materials such as the tetracarboxylic dianhydride and the diamine compound."

[0122] As the dehydrating reagent, a conventionally known reagent can be used, for example, acid anhydrides such as acetic anhydride, propionic anhydride, benzoic anhydride, trifluoroacetic anhydride, and chloroacetic anhydride.

[0123] The method of reacting raw materials such as tetracarboxylic dianhydride and diamine compound in a solvent is not particularly limited. The order and method of adding raw materials such as tetracarboxylic dianhydride and diamine compound are also not particularly limited. For example, there is a method of obtaining a polyimide resin precursor such as a compound represented by the formula (0) and a compound having a functional group that reacts with a terminal ring-closed product (such as a compound represented by the formula (5)) by ring-opening the terminal of tetracarboxylic dianhydride with water or alcohol and then reacting with a diamine compound. The amount of these compounds can be appropriately adjusted by the ratio of tetracarboxylic dianhydride and diamine compound, the amount of alcohol, etc.

[0124] Examples of the alcohol include monohydric aliphatic alcohols such as methanol, ethanol, 1-propanol, 2-propanol, tert-butyl alcohol, 1-butanol, 2-methylpropanol, 1-pentanol, 1-hexanol, 1-heptanol, 2-ethyl-1-hexanol, 1-octanol, 1-decanol, and diacetone alcohol; dihydric aliphatic alcohols such as ethylene glycol, propylene glycol, trimethylene glycol, butanediol, hexamethylene glycol, 1,5-pentanediol, 2-butene-1,4-diol, and 2-methyl-2,4-pentanediol; and trihydric aliphatic alcohols such as glycerol and 1,2,6-hexanetriol. In particular, methyl alcohol and ethyl alcohol are preferred from the viewpoint of elimination during firing. These alcohols may be used alone or in any ratio and combination of two or more types of water and alcohol.

[0125] In order to enhance the reactivity of the tetracarboxylic dianhydride with water, alcohol, etc., a catalyst may be used as necessary, as described later. Examples of the catalyst include pyridine, isoquinoline, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, 4-phenoxypyridine, 2,6-dimethylpyridine, N,N-dimethylethanolamine, dimethylaminopyridine, triethanolamine, etc. Among these, those having a substituent are preferred, and N,N-dimethylethanolamine, dimethylaminopyridine, and triethanolamine having an amine as the substituent are particularly preferred.

[0126] The amount of the diamine compound used in the reaction is usually 0.7 mol or more, preferably 0.8 mol or more, more preferably 0.9 mol or more, and usually 1.3 mol or less, preferably 1.2 mol or less, more preferably 1.1 mol or less, relative to 1 mol of the tetracarboxylic dianhydride. By setting the amount of the diamine compound within such a range, polyimide resins with a high polymerization degree can be obtained, and film-forming properties and film-forming properties tend to be improved.

[0127] The concentrations of the raw materials, such as the tetracarboxylic dianhydride and the diamine compound, in the solvent can be appropriately set depending on the reaction conditions and the viscosity of the resulting polyimide resin composition.

[0128] The total concentration of the raw materials such as tetracarboxylic dianhydride and diamine compound is not particularly limited, but is usually 1% by weight or more, preferably 5% by weight or more, and usually 70% by weight or less, preferably 50% by weight or less, based on the total amount of the solution containing the raw materials such as tetracarboxylic dianhydride and diamine compound and the solvent. By carrying out the polymerization in this concentration range, it is possible to obtain a uniform polyimide resin with a high degree of polymerization. By carrying out the polymerization at a total concentration of 1% by weight or more of the raw materials such as tetracarboxylic dianhydride and diamine compound, the degree of polymerization of the polyimide resin becomes sufficiently high, and the strength of the finally obtained polyimide resin coating tends to be obtained. On the other hand, by having the total concentration of the raw materials such as tetracarboxylic dianhydride and diamine compound be 70% by weight or less, the increase in the solution viscosity is suppressed, and stirring tends to be easy.

[0129] When obtaining a polyimide resin in a solvent, the temperature at which raw materials such as a tetracarboxylic dianhydride and a diamine compound are reacted in the solvent is not particularly limited as long as the reaction proceeds at the temperature, but is usually 20° C. or higher, preferably 40° C. or higher, and usually 240° C. or lower, preferably 220° C. or lower. The reaction time is usually 1 hour or more, preferably 2 hours or more, and usually 100 hours or less, preferably 42 hours or less. By carrying out the reaction under such conditions, it tends to be possible to obtain a polyimide resin in good yield at low cost. The pressure during the reaction may be normal pressure, elevated pressure, or reduced pressure. The atmosphere may be air or an inert atmosphere, but an inert atmosphere is preferred from the viewpoint of the bending conformability of the resulting polyimide resin and, ultimately, the metal insulating coating material of the present invention.

[0130] When obtaining a polyimide resin precursor in a solvent, the temperature at which raw materials such as a tetracarboxylic dianhydride and a diamine compound are reacted in the solvent is not particularly limited as long as the reaction proceeds at the temperature, but is usually 0° C. or higher, preferably 20° C. or higher, and usually 120° C. or lower, preferably 100° C. or lower. The reaction time is usually 1 hour or more, preferably 2 hours or more, and usually 100 hours or less, preferably 42 hours or less. By carrying out the reaction under such conditions, it tends to be possible to obtain a polyimide resin precursor at low cost and in good yield. The pressure during the reaction may be normal pressure, elevated pressure, or reduced pressure. The atmosphere may be air or an inert atmosphere, but an inert atmosphere is preferred from the viewpoint of the bending conformability of the resulting polyimide resin, and therefore of the metal insulating coating material of the present invention.

[0131] The solvent used in reacting the raw materials such as the tetracarboxylic dianhydride and the diamine compound is not particularly limited, and examples thereof include hydrocarbon solvents such as hexane, cyclohexane, heptane, benzene, naphtha, toluene, xylene, mesitylene, anisole, etc.; halogenated hydrocarbon solvents such as carbon tetrachloride, methylene chloride, chloroform, 1,2-dichloroethane, chlorobenzene, dichlorobenzene, fluorobenzene, etc.; ether solvents such as diethyl ether, tetrahydrofuran, 1,4-dioxane, methoxybenzene, etc.; ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone, etc.; ethylene glycol, etc. Examples of suitable solvents include glycol solvents such as glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and propylene glycol monomethyl ether acetate; amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfone solvents such as dimethyl sulfoxide; heterocyclic solvents such as pyridine, picoline, lutidine, quinoline, and isoquinoline; phenol solvents such as phenol and cresol; and lactone solvents such as γ-butyrolactone, γ-valerolactone, and δ-valerolactone. Among these, glycol solvents, amide solvents, and lactone solvents are preferred because they have high solubility for polyimide resins and the composition viscosity tends to be easy to handle in normal production equipment. These solvents may be used alone or in any combination of two or more kinds in any ratio.

[0132] In order to increase the reactivity of raw materials such as tetracarboxylic dianhydride and diamine compound, an organic amine compound may be used as a catalyst. Examples of the organic amine compound include tertiary alkylamines such as trimethylamine, triethylamine, tripropylamine, and tributylamine; alkanolamines such as triethanolamine, N,N-dimethylethanolamine, and N,N-diethylethanolamine; alkylenediamines such as triethylenediamine; pyridines such as pyridine; pyrrolidines such as N-methylpyrrolidine and N-ethylpyrrolidine; piperidines such as N-methylpiperidine and N-ethylpiperidine; imidazoles such as imidazole; quinolines such as quinoline and isoquinoline. These may be used alone or in any ratio and combination of two or more.

[0133] The obtained polyimide resins can also be recovered by adding them to a poor solvent to precipitate them in a solid state. In this case, the poor solvent to be used is not particularly limited and can be appropriately selected depending on the type of polyimide resin. Examples of the poor solvent include ether solvents such as diethyl ether or diisopropyl ether; ketone solvents such as acetone, methyl ethyl ketone, isobutyl ketone, methyl isobutyl ketone; and alcohol solvents such as methanol, ethanol, and isopropyl alcohol. Among them, alcohol solvents such as methanol and isopropyl alcohol are preferred because they tend to efficiently obtain precipitates and have low boiling points and are easy to dry. These poor solvents may be used alone or in any ratio and combination of two or more.

[0134] The polyimide resin obtained by precipitation in a poor solvent can also be redissolved in a solvent and used as a composition.

[0135] <Weight average molecular weight> The weight average molecular weight (Mw) of the polyimide resins used in the present invention is not particularly limited, but is usually 1,000 or more, preferably 3,000 or more, more preferably 5,000 or more in terms of polystyrene. Also, it is usually 200,000 or less, preferably 150,000 or less, more preferably 100,000 or less. By setting Mw within this range, the composition viscosity tends to be easy to handle in the production equipment, which is preferable. The weight average molecular weight of polyimide resins in terms of polystyrene can be determined by gel permeation chromatography (GPC).

[0136] <Imidization rate> In the case where the polyimide resin in the composition of the present invention becomes insoluble in a solvent as a result of imidization, 1 The imidization rate calculated by H-NMR is preferably 1 mol% or more, more preferably 3 mol% or more, even more preferably 5 mol% or more, particularly preferably 8 mol% or more, and preferably 35 mol% or less, more preferably 30 mol% or less, even more preferably 25 mol% or less, particularly preferably 20 mol% or less. By controlling the imidization rate within the above preferred range, a polyimide resin with a good balance between elastic modulus and elongation at break can be obtained. On the other hand, when the imidization does not result in insolubilization in a solvent, the imidization rate is not particularly limited, but is, for example, 90 mol% or more.

[0137] <Polyimide resin concentration> The concentration of the polyimide resin precursor and / or polyimide resin in the composition of the present invention, i.e., the polyimide resins, is preferably 15% by weight or more and 40% by weight or less. This concentration is preferably 16% by weight or more, more preferably 18% by weight or more, and preferably 35% by weight or less, more preferably less than 30% by weight, and even more preferably 28% by weight or less. By setting the concentration of the polyimide resins in the above range, the productivity tends to improve while maintaining the film formability.

[0138] The concentration of the polyimide resins in the composition of the present invention can be appropriately confirmed by a conventionally known method. For example, the concentration can be determined by distilling off the solvent and other components in the composition using a method such as drying under reduced pressure, and then determining the concentration from the weight ratio before and after the distillation. Alternatively, the concentration can be determined from the charged weight of the composition.

[0139] [solvent] The solvent contained in the composition of the present invention is usually a solvent used as a reaction solvent in the above-mentioned method for producing a polyimide resin according to the present invention, or a solvent used to redissolve a polyimide resin precipitated in a solid state with a poor solvent after the production of the polyimide resin to prepare a composition, and examples of the solvents included in the composition include the solvents exemplified as reaction solvents used in the production of polyimide resins.

[0140] The solvent contained in the composition of the present invention is preferably a solvent having a boiling point of 80° C. or higher from the viewpoint of the solubility of polyimide resins and residual solvent after baking, and from this viewpoint, the boiling point of the solvent is more preferably 100° C. or higher, and further preferably 120° C. or higher. On the other hand, if the boiling point of the solvent is excessively high, the solvent is likely to remain after baking, so the boiling point of the solvent is preferably 250° C. or lower, particularly preferably 210° C. or lower.

[0141] Examples of the solvent that satisfies the above boiling point condition include, among the solvents mentioned above as the reaction solvent, glycol solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and propylene glycol monomethyl ether acetate; amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfone solvents such as dimethyl sulfoxide; heterocyclic solvents such as picoline, lutidine, quinoline, and isoquinoline; phenol solvents such as phenol and cresol; lactone solvents such as γ-butyrolactone, γ-valerolactone, and δ-valerolactone; etc. Among them, glycol solvents, amide solvents, and lactone solvents are preferred because they have high solubility for polyimide resins and the composition viscosity tends to be easy to handle in normal production equipment. These solvents may be used alone or in any combination of two or more kinds in any ratio.

[0142] [Polymers with heterocycles in the side chains] The composition of the present invention may contain the following polymer having a heterocycle in the side chain. When the composition of the present invention contains a polymer having a heterocycle in the side chain, the flex resistance of the obtained polyimide resin coating can be improved.

[0143] The polymer having a heterocycle in the side chain used in this case is usually a polymer of a heterocyclic compound having a vinyl group, and may be either a homopolymer (single polymer) or a copolymer.

[0144] Examples of heterocyclic compounds having a vinyl group, which are monomer components constituting a polymer having a heterocycle in a side chain, include vinylpyrrolidone, vinylpyridine, vinylpyrrole, vinylporphyrin, vinylindole, vinylphthalimide, and vinylthiophene. Among these, heterocyclic compounds containing nitrogen atoms are preferred because they have excellent compatibility with polyimide resins. In addition, heterocyclic compounds having 5-membered rings and / or 6-membered rings are preferred from the viewpoint of solubility in solvents.

[0145] Examples of homopolymers made of these heterocyclic compounds include polyvinylpyrrolidone, polyvinylpyridine, polyvinylpyrrole, polyvinylporphyrin, polyvinylindole, polyvinylphthalimide, and polyvinylthiophene.

[0146] The polymer having a heterocycle in the side chain may be a copolymer of two or more of these heterocyclic compounds having a vinyl group, or a copolymer of one or more of the heterocyclic compounds having a vinyl group and one or more of other vinyl monomers. Examples of the copolymer of the heterocyclic compound having a vinyl group and other vinyl monomers include polyvinylpyridine-polystyrene copolymer and polyvinylpyrrolidone-polyvinyl alcohol copolymer.

[0147] As the polymer having a heterocycle in a side chain, a heterocycle composed of a nitrogen atom and a carbon atom is preferable, and polyvinylpyrrolidone, polyvinylpyridine, or a copolymer containing vinylpyrrolidone and / or vinylpyridine as a copolymerization component is preferable, and polyvinylpyrrolidone and polyvinylpyridine are particularly preferable. The copolymer containing vinylpyrrolidone and / or vinylpyridine as a copolymerization component preferably contains 50 mol % or more of structural units derived from vinylpyrrolidone and / or vinylpyridine with respect to all structural units derived from the monomers constituting the copolymer.

[0148] The molecular weight of the polymer having a heterocycle in the side chain used in the present invention is preferably 5,000 to 2,000,000, more preferably 10,000 to 2,000,000, further preferably 20,000 to 1,800,000, and particularly preferably 30,000 to 1,500,000. When the molecular weight of the polymer having a heterocycle in the side chain is within the above range, when the polymer is coordinated between the molecules of the polyimide resin, the function of weakening the intermolecular force of the polyimide tends to be sufficiently obtained. The "molecular weight" referred to here is the weight average molecular weight (Mw) and is a value calculated in terms of polystyrene measured by gel permeation chromatography (GPC).

[0149] The polymer having a heterocycle in the side chain may be used alone or in any combination of two or more kinds in any ratio.

[0150] When the composition of the present invention contains a polymer having a heterocycle in the side chain, the content of the polymer having a heterocycle in the side chain is preferably 0.1 to 7 parts by weight per 100 parts by weight of polyimide resins. When the content of the polymer having a heterocycle in the side chain is 0.1 parts by weight or more per 100 parts by weight of polyimide resins, the effect of improving the flex resistance by blending the polymer having a heterocycle in the side chain tends to be sufficiently obtained. When the content of the polymer having a heterocycle in the side chain is 7 parts by weight or less per 100 parts by weight of polyimide resins, molecular scission of the polymer having a heterocycle in the side chain due to heat during polyimide resin coating molding is suppressed, and the desired flex resistance is easily obtained. The content of the polymer having a heterocycle in a side chain in the composition of the present invention is more preferably 0.5 to 5 parts by weight based on 100 parts by weight of polyimide resins.

[0151] The composition of the present invention containing the polymer having a heterocycle in a side chain in the above-mentioned ratio is produced by mixing the polymer having a heterocycle in a side chain with the polyimide resin composition produced by the above-mentioned method or the like.

[0152] [Other ingredients] From the viewpoint of imparting coatability, processing properties, various functions, etc., the composition of the present invention may contain surfactants, defoamers, colorants such as organic pigments, antioxidants, ultraviolet absorbers, stabilizers such as hindered amine light stabilizers, antistatic agents, lubricants, antistatic agents, flame retardants, plasticizers, release agents, leveling agents, etc. The composition of the present invention may contain resins other than polyimide resins, inorganic fillers, or organic fillers within the scope not impairing the object of the present invention.

[0153] Examples of inorganic fillers include inorganic oxides such as silica, diatomaceous earth, beryllium oxide, pumice, and pumice balloons; hydroxides such as aluminum hydroxide and magnesium hydroxide; metal carbonates such as calcium carbonate, magnesium carbonate, basic magnesium carbonate, dolomite, and dawsonite; metal sulfates and sulfites such as calcium sulfate, barium sulfate, ammonium sulfate, and calcium sulfite; silicates such as talc, clay, mica, asbestos, glass fibers, glass balloons, glass beads, calcium silicate, montmorillonite, and bentonite; powdered, granular, plate-like, or fibrous inorganic fillers such as molybdenum sulfide, zinc borate, barium metaborate, calcium borate, sodium borate, and boron fibers; and powdered, granular, fibrous, or whisker-like ceramic fillers such as silicon carbide, silicon nitride, zirconia, aluminum nitride, titanium carbide, and potassium titanate.

[0154] Examples of organic fillers include husk fibers such as rice husks, wood flour, cotton, jute, paper strips, cellophane strips, aromatic polyamide fibers, cellulose fibers, nylon fibers, polyester fibers, polypropylene fibers, thermosetting resin powders, and rubber. The filler may be a nonwoven fabric or the like processed into a flat plate shape, or a mixture of a plurality of materials may be used.

[0155] These various fillers and additional ingredients may be added at any stage during any process for producing the composition of the present invention.

[0156] Among other components, it is preferable to include a leveling agent, since the smoothness of the polyimide resin coating formed tends to improve. As the leveling agent, for example, a silicone-based compound can be mentioned. There is no particular limitation on the silicone-based compound, but for example, polyether-modified siloxane, polyether-modified polydimethylsiloxane, polyether-modified hydroxyl-containing polydimethylsiloxane, polyether-modified polymethylalkylsiloxane, polyester-modified polydimethylsiloxane, polyester-modified hydroxyl-containing polydimethylsiloxane, polyester-modified polymethylalkylsiloxane, aralkyl-modified polymethylalkylsiloxane, high-polymer silicone, amino-modified silicone, amino derivative silicone, phenyl-modified silicone, and polyether-modified silicone can be mentioned.

[0157] [viscosity] The viscosity of the composition of the present invention is preferably 10,000 cP or less. This viscosity is more preferably 8,000 cP or less, and even more preferably 6,000 cP or less. There is no particular lower limit to the viscosity, but it is, for example, 10 cP or more. By setting the viscosity of the composition of the present invention to 10,000 cP or less, unevenness in the coating film formed by the composition of the present invention is reduced, and the coating property tends to be improved. In particular, when applying to a linear or rod-shaped body such as an electric wire, unevenness in the coating film thickness is likely to occur, and the above-mentioned viscosity is preferable.

[0158] There is no particular limitation on the method for measuring the viscosity of the composition of the present invention, but the viscosity here is the rotational viscosity measured at 30° C. using an E-type viscometer.

[0159] [Glass transition temperature (Tg)] The fired film of the composition of the present invention has a glass transition temperature (Tg) measured by a DMS method (dynamic thermomechanical analyzer) of preferably 250° C. or higher, more preferably 260° C. or higher, even more preferably 270° C. or higher, and particularly preferably 280° C. or higher. From the viewpoint of heat resistance, it is preferable that the glass transition temperature is equal to or higher than the above lower limit. On the other hand, the upper limit of the glass transition temperature (Tg) of the fired film of the composition of the present invention is not particularly limited, but is usually 400° C. or lower, and some films do not have a Tg. The glass transition temperature (Tg) as determined by the DMS method can be measured by the method described in the Examples below.

[0160] [Application] The composition of the present invention can be used for applications such as display substrates, FPCs, electric wire coatings, thin-film solar cell substrates, organic optical semiconductor lighting, LED mounting substrates, sensor substrates, and switch substrates. Due to its high heat resistance, flex resistance, wear resistance and adhesion properties, the composition of the present invention can be used for insulating coating materials other than those mentioned above, metal coating materials such as metal wires and metal plates, polyimide films, polyimide laminates, etc. Note that insulation refers to blocking current from flowing to peripheral parts or conductors in electric machines and circuits.

[0161] In any of the applications, the composition of the present invention is usually formed into a film on a substrate and then used for various applications.

[0162] There are no particular limitations on the method for forming a film using the composition of the present invention, and examples of the method include a method of coating the composition on a substrate or the like. Examples of the coating method include die coating, spin coating, dip coating, screen printing, spraying, casting, a method using a coater, a coating method by spraying, a dipping method, a calendar method, a dripping method, etc. These methods can be appropriately selected depending on the area to be coated and the shape of the surface to be coated.

[0163] There is no particular limitation on the method for volatilizing the solvent contained in the film formed by coating or the like. Usually, the carrier substrate on which the composition is applied is heated to volatilize the solvent. There is no particular limitation on the heating method, and examples thereof include hot air heating, vacuum heating, infrared heating, microwave heating, and heating by contact using a hot plate, hot roll, or the like.

[0164] In the above case, the heating temperature can be a suitable temperature depending on the type of solvent. The heating temperature is usually 40°C or higher, preferably 100°C or higher, more preferably 200°C or higher, particularly preferably 300°C or higher, and usually 1000°C or lower, preferably 700°C or lower, more preferably 600°C or lower, particularly preferably 500°C or lower. When the heating temperature is 40°C or higher, it is preferable in that the solvent is sufficiently volatilized. When the heating temperature is 300°C or higher, the imidization reaction proceeds quickly, making it possible to perform baking in a short time. The heating atmosphere may be air or an inert atmosphere, and is not particularly limited. When the film to be formed is required to be colorless and transparent, it is preferable to heat the film in an inert atmosphere such as nitrogen in order to suppress coloration.

[0165] <Polyimide film> When the composition of the present invention is used to form a polyimide film, the thickness of the polyimide film is usually 1 μm or more, preferably 2 μm or more, and usually 300 μm or less, preferably 200 μm or less. When the thickness is 1 μm or more, the polyimide film becomes an autonomous film with sufficient strength, and the handling property tends to be improved. When the thickness is 300 μm or less, the uniformity of the film tends to be easily ensured.

[0166] The performance required of the polyimide film depends on the application, but it is preferable that the polyimide film has the following mechanical strength.

[0167] The tensile modulus of the polyimide film is not particularly limited, but from the viewpoint of abrasion resistance, it is preferably 2000 MPa or more, more preferably 2500 MPa or more, even more preferably 3000 MPa or more, and particularly preferably 3500 MPa or more, while from the viewpoint of bending resistance, it is preferably 10 GPa or less, more preferably 5000 MPa or less. The tensile elongation of the polyimide film is not particularly limited, but from the viewpoint of bending resistance, it is preferably 20% or more, more preferably 30% or more, and even more preferably 50% or more. From the viewpoint of bending followability, there is no particular upper limit, and a higher elongation is preferable.

[0168] By providing the polyimide film with such a tensile modulus and tensile elongation, both high modulus and high elongation are achieved, and the film is suitable for use in various applications such as surface protection layers, device substrates, insulating films, wiring films, etc. If the polyimide film satisfies such tensile modulus and tensile elongation when formed into a film, it is also suitable for use as a metal coating material described below. For example, the film satisfies the bending resistance and wear resistance required for the recent demand for small size and high output of motors.

[0169] The tensile modulus and tensile elongation of the polyimide film are measured by the method described in the Examples section below.

[0170] A polyimide film made from the composition of the present invention can be obtained, for example, by applying the composition of the present invention to a substrate that serves as a support, as described above, followed by heating and peeling the film from the support. The method for peeling the polyimide film from the support is not particularly limited, but a physical peeling method or a laser peeling method is preferred because it allows peeling without impairing the performance of the film.

[0171] Examples of the physical peeling method include a method in which the periphery of a laminate consisting of a polyimide film / support is cut off to obtain a polyimide film, a method in which the periphery is sucked to obtain a polyimide film, and a method in which the periphery is fixed and the support is moved to obtain a polyimide film.

[0172] <Polyimide laminate> As described above, the composition of the present invention is applied to a substrate and then heated to form a polyimide film on the substrate. This film can be integrated with the substrate without being peeled off to form a polyimide laminate.

[0173] The substrate is preferably hard and heat resistant. In other words, it is preferable to use a material that does not deform under the temperature conditions required in the manufacturing process. Specifically, it is preferable that the substrate is made of a material that has a glass transition temperature of usually 200° C. or higher, preferably 250° C. or higher. Examples of such substrates include glass, ceramics, metals, and silicon wafers.

[0174] When glass is used as the substrate, the glass to be used is not particularly limited, but examples thereof include blue plate glass (alkali glass), high silicate glass, soda-lime glass, lead glass, aluminoborosilicate glass, alkali-free glass (borosilicate glass, Corning Eagle XG, etc.), and aluminosilicate glass. When a metal is used as the substrate, the metal to be used is not particularly limited, but examples thereof include gold, silver, copper, aluminum, iron, etc. Various alloys of these metals may also be used.

[0175] The shape of the substrate is not particularly limited, and may be a film, a sheet, or a plate, in which case the substrate may be flat, curved, or have steps. The substrate may also be linear or rod-shaped.

[0176] The form of the polyimide resin coating on these substrates is not particularly limited, and can be appropriately formed according to the shape and use of the substrate. For example, the substrate can be coated on the entire surface, one side, both sides, end faces, etc., and the substrate can be coated on the entire surface or only a part of it. The polyimide resin coating may be a single layer or a multilayer.

[0177] <Metal insulating coating material> The metal insulating coating material of the present invention has a resin layer made of the above-mentioned composition of the present invention, and because of its excellent adhesion, high heat resistance, bending resistance, and abrasion resistance in particular, it can be suitably used as an insulating coating material for electric wires and cables, low-temperature storage tanks, space insulation materials, enamel coating materials for integrated circuits, etc.

[0178] There are no particular limitations on the type of metal to be coated with the composition of the present invention, but examples include gold, silver, copper, aluminum, iron, and alloys containing one or more of these metals.

[0179] The resin coating layer made of the composition of the present invention can be formed in the same manner as the above-mentioned method for forming a polyimide film, and is usually formed to a thickness of about 1 to 200 μm. EXAMPLES

[0180] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as it does not deviate from the gist of the invention. The values ​​of various production conditions and evaluation results in the following examples are meant as preferred upper or lower limit values ​​in the embodiments of the present invention, and the preferred range may be a range defined by a combination of the above-mentioned upper or lower limit values ​​and the values ​​of the following examples or values ​​of the examples.

[0181] [Evaluation method] The polyimide resins, compositions and polyimide films obtained in the following Examples and Comparative Examples were evaluated by the following methods.

[0182] [Imidization rate of polyimide resins] Polyimide resin precursor 1 The imidization rate was calculated by quantifying the amide protons in the amic acid portion and the aromatic protons in the main chain from H-NMR measurements. 6 The imidization rate was calculated using the following formula with TMS as the reference peak (0 ppm). Imidization rate (mol%) = (B / 2) / A x 100 In the above formula, A is the peak integral value of aromatic protons (7-8 ppm) divided by the number of aromatic protons contained in the repeating unit of polyamic acid, and B is the peak integral value of amide protons (10-11 ppm) in the amic acid structure.

[0183] [Viscosity of composition] The rotational viscosity at 30°C was measured using a Brookfield E-type viscometer, DV-I+.

[0184] [Flexibility (tensile elongation) and abrasion resistance (tensile modulus) of polyimide film] In accordance with JIS K6301, a tensile test was carried out on a strip-shaped polyimide film specimen measuring 9 mm in width, 80 mm in length, and approximately 15 μm in thickness using a tensile testing machine (manufactured by Orientec Co., Ltd., product name "Tensilon STB-1225L") with a chuck distance of 30 mm and a tensile speed of 10 mm / min. A stress-strain curve was created to determine the tensile modulus (MPa), and the elongation at the time the specimen broke was measured, which was recorded as the tensile elongation (%). The higher the tensile modulus, the more excellent the abrasion resistance is evaluated to be. The greater the tensile elongation, the more excellent the flexibility and bending resistance (flexibility).

[0185] [Heat resistance of polyimide film (glass transition temperature)] Using a dynamic thermomechanical measuring device (DMS / SS6100, manufactured by SII Nano Technology Co., Ltd.), the storage modulus and loss modulus of the sample were measured under the following measurement conditions in response to a vibration load, and the glass transition temperature (Tg) was calculated from the loss tangent. That is, the peak top of the loss tangent (tan δ) obtained by dividing the storage modulus (E') of a polyimide film test piece by the loss modulus (E") was defined as the glass transition temperature (Tg). This glass transition temperature (Tg) corresponds to the glass transition temperature (Tg) of a polyimide resin, and the higher the Tg, the more excellent the heat resistance is evaluated to be. (DMS measurement conditions) Measurement temperature range: 30℃~500℃ (heating rate: 5℃ / min) Tensile load: 5g Test piece shape: 6mm x 20mm

[0186] [Adhesion of polyimide film] A polyimide film (baked film) was created on a copper plate measuring 50 mm x 50 mm x 0.3 mm thick, and 25 squares (5 x 5) were cut into the polyimide film in a checkerboard pattern with a width of 2 mm. The adhesion between the copper plate and the polyimide film was confirmed using a cupping tester (KT-SP4305, manufactured by Cortec Co., Ltd.) under the following measurement conditions. The test was performed four times, and if at least one square of the polyimide film had completely peeled off from the copper plate after the test, the adhesion was judged to be poor (NG), and otherwise the adhesion was judged to be good (good). (Cupping test measurement conditions) Measurement speed: 0.2mm / s Push-in distance: 9mm Test piece shape: 50mm x 50mm

[0187] [Raw materials used] The raw materials used in the production of the compositions in the examples and comparative examples are as follows. 3,3',4,4'-Biphenyltetracarboxylic dianhydride (BPDA): Mitsubishi Chemical Corporation 3,3',4,4'-Benzophenonetetracarboxylic dianhydride (BTDA): Tokyo Chemical Industry Co., Ltd. 4,4'-Diaminodiphenyl ether (ODA): Wakayama Seika Kogyo Co., Ltd. 4,4'-Diaminobenzanilide (DABA): Wakayama Seika Kogyo Co., Ltd. 3,3'-Dihydroxybenzidine (DHB): Wakayama Seika Kogyo Co., Ltd. N,N'-bis-(4-aminophenyl)terephthalamide (DATA): Wakayama Seika Kogyo Co., Ltd. 4,4´-Diaminodiphenylsulfone (ASN): Wakayama Seika Kogyo Co., Ltd. N,N-Dimethylacetamide (DMAc) (boiling point: 165°C): Mitsubishi Gas Chemical Company, Inc. Polyvinylpyrrolidone K-30 (PVP K-30, molecular weight 45,000): manufactured by Daiichi Kogyo Seiyaku Co., Ltd. N,N-Dimethylethanolamine (DMEA): Tokyo Chemical Industry Co., Ltd. Methanol: Wako Pure Chemical Industries, Ltd.

[0188] [Synthesis Examples, Examples and Comparative Examples] [Synthesis of polyimide resins]

[0189] <Synthesis Example 1> 57.6 parts by weight of BPDA, 0.37 parts by weight of methanol, 0.03 parts by weight of DMEA, and 243 parts by weight of DMAc were added to a four-neck flask equipped with a nitrogen gas inlet tube, a condenser, and a stirrer, and the mixture was reacted for 2 hours at 70° C. with stirring. 35.3 parts by weight of ODA, 4.4 parts by weight of DABA, and 190 parts by weight of DMAc were further added, and the mixture was reacted for 4 hours at 80° C. to obtain polyimide resins 1 with a solid content concentration of 18% by weight. The solid content concentration here corresponds to the concentration of polyimide resins, and is a value calculated from the charged amount. The same applies to the following synthesis examples.

[0190] <Synthesis Example 2> 57.9 parts by weight of BPDA, 0.18 parts by weight of methanol, 0.016 parts by weight of DMEA, and 257 parts by weight of DMAc were added to a four-neck flask equipped with a nitrogen gas inlet tube, a condenser, and a stirrer, and the mixture was reacted for 2 hours at 70° C. with stirring. 29.6 parts by weight of ODA, 11.2 parts by weight of DABA, and 186 parts by weight of DMAc were further added, and the mixture was reacted for 4 hours at 80° C. to obtain polyimide resins 2 with a solid content concentration of 18% by weight.

[0191] <Synthesis Example 3> A reaction was carried out in the same manner as in Synthesis Example 2, except that the amount of methanol used was changed to 0.37 parts by weight and the amount of DMEA used was changed to 0.032 parts by weight, to obtain a polyimide resin 3 having a solid content concentration of 18% by weight.

[0192] <Synthesis Example 4> 57.0 parts by weight of BPDA, 0.37 parts by weight of methanol, 0.03 parts by weight of DMEA, and 257 parts by weight of DMAc were added to a four-neck flask equipped with a nitrogen gas inlet tube, a condenser, and a stirrer, and the mixture was reacted for 2 hours at 70° C. with stirring. 27.2 parts by weight of ODA, 13.2 parts by weight of DABA, and 187 parts by weight of DMAc were further added, and the mixture was reacted for 4 hours at 80° C. to obtain polyimide resin 4 having a solid content concentration of 18% by weight.

[0193] <Synthesis Example 5> Polyimide resin 5 was obtained by carrying out the reaction in the same manner as in Synthesis Example 4, except that the amount of methanol used was changed to 0.43 parts by weight, the amount of DMEA used was changed to 0.037 parts by weight, and the solid content concentration was changed to 25% by weight.

[0194] <Synthesis Example 6> Polyimide resin 6 was obtained by carrying out the reaction in the same manner as in Synthesis Example 4, except that the amount of methanol used was changed to 0.49 parts by weight, the amount of DMEA used was changed to 0.042 parts by weight, and the solid content concentration was changed to 25% by weight.

[0195] <Synthesis Example 7> Polyimide resin 7 was obtained by carrying out the reaction in the same manner as in Synthesis Example 4, except that the amount of methanol used was changed to 0.55 parts by weight, the amount of DMEA used was changed to 0.047 parts by weight, and the solid content concentration was changed to 25% by weight.

[0196] <Synthesis Example 8> 57.0 parts by weight of BPDA, 0.37 parts by weight of methanol, 0.03 parts by weight of DMEA, and 173 parts by weight of DMAc were added to a four-neck flask equipped with a nitrogen gas inlet tube, a condenser, and a stirrer, and the mixture was reacted for 2 hours at 70° C. with stirring. 23.1 parts by weight of ODA, 17.5 parts by weight of DABA, and 106 parts by weight of DMAc were further added, and the mixture was reacted for 4 hours at 80° C. to obtain polyimide resin 8 having a solid content concentration of 25% by weight.

[0197] <Synthesis Example 9> 57.6 parts by weight of BPDA, 0.40 parts by weight of methanol, 0.02 parts by weight of DMEA, and 176 parts by weight of DMAc were added to a four-neck flask equipped with a nitrogen gas inlet tube, a condenser, and a stirrer, and the mixture was reacted for 2 hours at 70° C. with stirring. 35.3 parts by weight of ODA, 4.2 parts by weight of DHB, and 102 parts by weight of DMAc were further added, and the mixture was reacted for 4 hours at 80° C. to obtain polyimide resin 9 with a solid content concentration of 25% by weight.

[0198] <Synthesis Example 10> 58.3 parts by weight of BPDA, 30.3 parts by weight of ODA, 11.5 parts by weight of DABA, and 455 parts by weight of DMAc were added to a four-neck flask equipped with a nitrogen gas inlet tube, a condenser, and a stirrer. The mixture was heated with stirring and reacted at 80° C. for 6 hours to obtain polyimide resins 10 with a solid content of 18% by weight.

[0199] <Synthesis Example 11> 54.0 parts by weight of BPDA, 0.35 parts by weight of methanol, 0.02 parts by weight of DMEA, and 153 parts by weight of DMAc were added to a four-neck flask equipped with a nitrogen gas inlet tube, a condenser, and a stirrer, and the mixture was reacted for 2 hours at 70° C. with stirring. 27.6 parts by weight of ODA, 15.9 parts by weight of DATA, and 127 parts by weight of DMAc were further added, and the mixture was reacted for 4 hours at 80° C. to obtain polyimide resins 11 with a solid content concentration of 25% by weight.

[0200] <Synthesis Example 12> 56.6 parts by weight of BPDA, 0.37 parts by weight of methanol, 0.03 parts by weight of DMAP, and 160 parts by weight of DMAc were added to a four-neck flask equipped with a nitrogen gas inlet tube, a condenser, and a stirrer, and the mixture was reacted for 2 hours at 70° C. with stirring. 28.9 parts by weight of ODA, 11.9 parts by weight of ASN, and 120 parts by weight of DMAc were further added, and the mixture was reacted for 4 hours at 80° C. to obtain polyimide resins 12 with a solid content concentration of 25% by weight.

[0201] <Synthesis Example 13> Into a four-neck flask equipped with a nitrogen gas inlet tube, a condenser, and a stirrer, 42.8 parts by weight of BPDA, 15.6 parts by weight of BTDA, 0.37 parts by weight of methanol, 0.03 parts by weight of DMAP, and 162 parts by weight of DMAc were added and reacted with stirring at 70° C. for 2 hours. 38.9 parts by weight of ODA and 121 parts by weight of DMAc were further added, and the reaction was continued at 80° C. for 4 hours to obtain polyimide resins 13 with a solid content concentration of 25% by weight.

[0202] The synthesis conditions and evaluation results of the polyimide resins 1 to 13 obtained in Synthesis Examples 1 to 13 are shown in Table 1. The amount of hydrogen bond-forming monomer introduced in Table 1 is a value determined from the charged amount.

[0203] [Table 1]

[0204] [Preparation of Composition] Compositions PI-1 to PI-13 were prepared according to the blending ratios shown in Table 2. The amount of each component used shown in Table 2 is shown as parts by weight in terms of solid content. The viscosity of the prepared composition was measured by the method described above, and the results are shown in Table 2. In addition, additives were prepared so that the concentration of polyimide resins in the composition would be the concentration shown in Table 2.

[0205] [Preparation of polyimide film for evaluating bending resistance, abrasion resistance, and heat resistance] The compositions PI-1 to PI-13 were applied to a glass plate using a spin coater and cured by heating on a hot plate at 500°C for 6 minutes, after which the glass plate-polyimide resin coating laminate was removed from the drying oven and cooled to room temperature, after which the laminate was immersed in boiling water at 90°C to peel off the glass and polyimide film.

[0206] The results of evaluation of the bending resistance, abrasion resistance and heat resistance of the obtained polyimide film are shown in Table 2.

[0207] [Preparation of laminate for adhesion evaluation] The compositions of PI-1, PI-3, PI-4, PI-6, PI-9, PI-10, and PI-11 were applied to a copper plate using a spin coater, and then heated on a hot plate at 500°C for 6 minutes to harden the copper plate-polyimide resin coating laminate was removed from the drying oven. The laminate was returned to room temperature and then evaluated for adhesion. The results are shown in Table 2.

[0208] [Table 2]

[0209] As is clear from the above results, the compositions of Examples 1 to 9 provide polyimide resin coatings with high heat resistance and excellent mechanical properties and adhesion. It was also shown that the compositions of Examples 1 to 9 can have a polyimide resin concentration of 15% by weight or more and 40% by weight or less, which provides good processability, and a low viscosity of 10,000 cP or less. In contrast, the composition of polyimide resin 10 of Comparative Example 1, which does not contain alcohol and does not involve a ring-opening reaction of an acid anhydride, has high viscosity and poor processability. The polyimide resin 11 used in Comparative Example 2 has a hydrogen bond-forming monomer introduced therein, but the hydrogen bond-forming monomer used has two linking groups (-C(O)NH-) having active hydrogen, so it does not satisfy the present invention, and this composition has low tensile elongation, insufficient bending resistance, and no adhesion. The polyimide resins 12 and 13 used in Comparative Examples 3 and 4 have low tensile elongation, inferior tensile modulus compared to other compositions, and insufficient mechanical properties, because no hydrogen bond-forming monomer is introduced therein.

[0210] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2019-013345 filed on January 29, 2019, the entirety of which is incorporated by reference.

Claims

1. A composition comprising a solvent and a polyimide resin precursor and / or a polyimide resin, The polyimide resin precursor and / or the polyimide resin is A compound represented by the following formula (0) and a compound represented by the following formula (0'): and A composition comprising a compound represented by the following formula (0) and a compound having a functional group capable of reacting with a terminal cyclic product of a compound represented by the following formula (0'): the functional group reactive with the terminal ring-closed product is a group selected from the group consisting of an amino group and an isocyanate group, The polyimide resin precursor and the polyimide resin have a structural unit represented by the following formula (3), and the imidization rate is 1 to 35 mol %. 【Chemistry 1】 In the above formula (0) and formula (0′), Each R' independently represents a hydrogen atom or an alkyl group. R ａ represents a tetracarboxylic acid residue. R ｂ represents a diamine residue. R ａ and / or R ｂ It has one linking group having active hydrogen and / or from 1 to 4 substituents having active hydrogen therein. p and q each represent any integer. 【Chemistry 2】 In the above formula (3), R １ ~R ８ may be the same or different and are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, or a hydroxyl group. X is a direct bond, an oxygen atom, a sulfur atom, an alkylene group having from 1 to 4 carbon atoms, a sulfonyl group, a sulfinyl group, a sulfide group, a carbonyl group, an amide group, an ester group, or a secondary amino group. n is an integer from 0 to 4.

2. The composition of claim 1 , wherein the solvent has a boiling point of 120° C. or higher.

3. 3. The composition according to claim 1, wherein a concentration of the polyimide resin precursor and / or the polyimide resin in the composition is 15% by weight or more and 40% by weight or less.

4. The composition according to any one of claims 1 to 3, wherein the polyimide resin precursor and / or the polyimide resin has at least one of a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2): 【Chemistry 3】

5. The linking group having active hydrogen or the substituent having active hydrogen is -NH-, ═NH, -C(O)NH-, -NHC(O)O-, -NHC(O)NH-, -NHC(S)NH-, -NH ２ 5. The composition according to claim 1, wherein the structure is selected from the group consisting of -OH, -C(O)OH, -SH, -C(O)N(OH)- and -C(O)SH.

6. The composition according to claim 5, wherein the linking group having an active hydrogen or the substituent having an active hydrogen has a structure selected from the group consisting of -C(O)NH-, -NHC(O)NH-, and -OH.

7. The composition according to any one of claims 1 to 6, wherein the glass transition temperature (Tg) of a fired film of the composition is 250°C or higher and 400°C or lower.

8. The composition according to any one of claims 1 to 7, wherein the viscosity of the composition is 10,000 cP or less.

9. A method for producing a metal insulating coating material, comprising a step of coating a metal with the composition according to any one of claims 1 to 8.

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