JPH1121454A - Polyamideimide resin composition, nonaqueous electrolyte secondary cell and circuit board each using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition useful for a bonding agent excellent in solvent solubility, etc., optical member utilizing its colorless transparency, and e.g. electrode binder for nonaqueous electrolyte secondary cells by copolymerizing dimer acid and also by setting the resultant logarithmic viscosity no less than a specific value. SOLUTION: This objective composition with a logarithmic viscosity of >=0.1 dl/g is obtained by dissolving into a polymerization solvent, trimellitic anhydride containing pref. cyclohexane dicarboxylic acid as part of an acid component, dimer acid of >=1 wt.%, diamine or diisocyanate containing pref. dicyclohexylmethane residue and/or isophorone residue as an amine residue, and, if the case may be, at least one selected from the group of epoxy resin, melamine compound and isocyanate compound, and by heating the resultant solution at 50 to 220 deg.C under stirring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel polyamide-imide resin composition. In more detail, coatings and adhesives with excellent solvent solubility, flexibility and heat resistance,
In addition, optical members such as liquid crystal displays utilizing colorless transparency,
The present invention relates to a polyamideimide resin composition useful for injection molding materials, fibers, films and the like. In particular, the present invention relates to a polyamideimide resin composition useful for an electrode binder of a non-aqueous electrolyte secondary battery utilizing chemical resistance and a circuit board adhesive utilizing high temperature adhesiveness.

[0002]

2. Description of the Related Art Polyamide-imide resins are originally excellent in heat resistance, chemical resistance, abrasion resistance, etc., and can be injection molded.
Although it is special, such as N-methyl-2-pyrrolidone, it can be dissolved in a solvent, so solution processing is possible, and it is applied to molding materials and heat-resistant insulating paints. However,
Conventional aromatic polyamide-imide resins are colored, and have properties such as being hard, brittle, and insoluble in solvents other than amide-based resins having a high boiling point, and their uses have been limited.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the state of the prior art, and has as its object to provide a novel polyamideimide resin having excellent solvent solubility, flexibility, and heat resistance, and a novel polyamideimide resin. And a non-aqueous electrolyte secondary battery and a circuit board using the same.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a polyamideimide obtained by copolymerizing dimer acid is useful.
The present invention has been completed. That is, the present invention comprises a copolymer of dimer acid and a logarithmic viscosity of 0.1 dl / g.
A polyamide-imide resin composition characterized by the above. In a preferred embodiment of the present invention, in the polyamideimide resin composition, 1% by weight or more of dimer acid is copolymerized, and cyclohexanedicarboxylic acid as a part of an acid component, dicyclohexylmethane residue and / or isophorone residue as an amine residue. A group is introduced. In a preferred aspect of the present invention, at least one compound selected from the group consisting of an epoxy compound, a melamine compound and an isocyanate compound is blended in the polyamideimide resin composition.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The polyamideimide resin composition of the present invention can be easily produced by dissolving trimellitic anhydride (acid chloride) and diamine or diisocyanate and dimer acid in a polymerization solvent and stirring with heating. can do.

[0006] In the present invention, the polymerization temperature of the polyamideimide is usually from 50 ° C to 220 ° C, more preferably from 80 ° C to 200 ° C.

In the case of synthesis by the diisocyanate method, for example, triethylamine, lutidine, picoline,
Amines such as triethylenediamine, lithium methoxide, sodium methoxide, potassium butoxide, potassium fluoride, alkali metal such as sodium fluoride, alkaline earth metal compounds, or metals such as cobalt, titanium, tin and zinc; The reaction may be performed in the presence of a metalloid compound catalyst.

As the acid component used for synthesizing the polyamideimide resin of the present invention, trimellitic anhydride and dimer acid are used. Further, a part thereof can be replaced with other polycarboxylic anhydrides, aliphatic and alicyclic dicarboxylic acids, aromatic dicarboxylic acids, tricarboxylic acids, and tetracarboxylic acids.

Examples of the polycarboxylic anhydride include pyromellitic anhydride, benzophenonetetracarboxylic anhydride, 3,3 ', 4,4'-diphenylsulfonetetracarboxylic anhydride, 3,3', 4 4,4'-diphenyltetracarboxylic anhydride, 4,4'-oxydiphthalic anhydride, ethylene glycol bisanhydrotrimellitate, propylene glycol bisanhydrotrimellitate, 1,4-butanediol bisanhydrotrimellitate Tate, hexamethylene glycol bisanhydrotrimellitate, polyethylene glycol bisanhydrotrimellitate, polypropylene glycol bisanhydrotrimellitate, etc., of which ethylene glycol bisanhydrotrimellitate is flexible Properties, adhesion, polymerization And preferred from a cost point.

The aliphatic and alicyclic dicarboxylic acids include, for example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, bimeric acid, suberic acid, azelaic acid, sebacic acid, undecandioic acid, dodecandioic acid, Examples include tridecandioic acid, cyclohexanedicarboxylic acid, and acid chlorides thereof. Among them, cyclohexanedicarboxylic acid is preferred from the viewpoint of polymerizability, transparency, heat resistance and chemical resistance.

As the aromatic dicarboxylic acid, for example, isophthalic acid, 5-tert-butyl-1,3-benzenedicarboxylic acid, terephthalic acid, diphenylmethane-4,
4'-dicarboxylic acid, diphenylmethane-2,4-dicarboxylic acid, diphenylmethane-3,4-dicarboxylic acid,
Diphenylmethane-3,3'-dicarboxylic acid, 1,2-
Diphenylethane-4,4'-dicarboxylic acid, diphenylethane-2,4-dicarboxylic acid, diphenylethane-
3,4-dicarboxylic acid, diphenylethane-3,3'-
Dicarboxylic acid, 2,2'-bis- (4-carboxyphenyl) propane, 2- (2-carboxyphenyl) -2
-(4-carboxyphenyl) propane, 2- (3-carboxyphenyl) -2- (4-carboxyphenyl)
Propane, diphenylether-4,4'-dicarboxylic acid, diphenylether-2,4-dicarboxylic acid, diphenylether-3,4-dicarboxylic acid, diphenylether-3,3'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid , Diphenyl sulfone-2,
4-dicarboxylic acid, diphenylsulfone-3,4-dicarboxylic acid, diphenylsulfone-3,3'-dicarboxylic acid, benzophenone-4,4'-dicarboxylic acid, benzophenone-3,3'-dicarboxylic acid, pyridine-2, 6
-Dicarboxylic acid, naphthalenedicarboxylic acid, bis-
[(4-carboxy) phthalimide] -4,4'-diphenyl ether, bis-[(4-carboxy) phthalimide] -α, α'-meta-xylene, and acid chlorides thereof. Among them, isophthalic acid and terephthalic acid are preferred.

As the tricarboxylic acid, for example, butane-
1,2,4-tricarboxylic acid, naphthalene-1,2,4
-Tricarboxylic acids, trimellitic acids and the like.
Moreover, these acid chlorides are mentioned.

Examples of the tetracarboxylic acid include butane-1,2,3,4-tetracarboxylic acid, pyromellitic acid, benzophenone-3,3 ', 4,4'-tetracarboxylic acid and diphenyl ether-3,3'. , 4,4'-tetracarboxylic acid, diphenylether-3,3 ', 4,4
4'-tetracarboxylic acid, biphenyl-3,3 ', 4,
4'-tetracarboxylic acid, naphthalene-2,3,6,7
-Tetracarboxylic acid, naphthalene-1,2,4,5-tetracarboxylic acid, naphthalene-1,4,5,8-tetracarboxylic acid and the like.

These acid components can be used alone or as a mixture of two or more, or together with trimellitic anhydride and dimer acid.

On the other hand, examples of the amine component include diamine and diisocyanate. Specifically, for example, m-phenylenediamine, p-phenylenediamine, oxydianiline, methylenediamine, hexafluoroisopropylidenediamine, diamino-m-xylylene, diamino-p-xylylene, 1,4-naphthalenediamine, 2,5-naphthalenediamine, 2,6-naphthalenediamine, 2,7-naphthalenediamine, 2,
2'-bis- (4-aminophenyl) propane, 2,
2'-bis- (4-aminophenyl) hexafluoropropane, 4,4'-diaminodiphenylsulfone, 4,
4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl ether, 3,4-diaminobiphenyl, 4,4'-diaminobenzophenone, 3,4-diaminodiphenyl ether, isopropylidene dianiline, 3,3'-diaminobenzophenone, o-tolidine, 2,4-tolylenediamine, 1,3-bis- (3-aminophenoxy) benzene, 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, 4,4′-bis-
Aromas such as (4-aminophenoxy) biphenyl, 2,2'-bis- [4- (4-aminophenoxy) phenyl] hexafluoropropane, 4,4'-diaminodiphenyl sulfide, and 3,3'-diaminodiphenyl sulfide Aliphatic diamines such as aliphatic diamines, ethylenediamine, propylenediamine, tetramethylenediamine, hexamethylenediamine, isophoronediamine, 4,4'-
Examples thereof include alicyclic diamines such as diaminodicyclohexylmethane, but are not particularly limited thereto.

Further, the amino group of the above diamine is represented by -N = C
= Isocyanates substituted with an O group. Among these, 4,4'-diaminodiphenylmethane (4,4
4'-diphenylmethane diisocyanate) and 4,4 '
A mixture of -diaminodicyclohexylmethane (4,4'-dicyclohexylmethane diisocyanate) and / or isophoronediamine (isophorone diisocyanate) is preferred in view of reactivity, cost, solubility, and flexibility. The above amine components may be used alone or as a mixture of two or more.

The above-mentioned acid component and amine component are usually synthesized in an equimolar mixture, but if necessary, one component may be slightly increased or decreased.

The present invention is characterized in that a dimer acid is copolymerized with a part of the acid component in order to further improve the flexibility and adhesiveness of the polyamide-imide resin composition.

Dimer acid is a compound represented by the following formula [1] and is usually a mixture containing a small amount of monomers and trimers, and contains an unsaturated group in the structure. It is also possible to use so-called hydrogenated dimer acid. In the polyamide resin composition of the present invention,
The copolymerization amount of the dimer acid is preferably at least 1% by weight, more preferably at least 5% by weight. If the copolymerization amount is less than 1% by weight, the flexibility and adhesiveness which are the objects of the present invention are not sufficiently improved.

[0020]

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Examples of the solvent used for the polymerization of the polyamideimide resin of the present invention include N-methyl-2-pyrrolidone, dimethylacetamide, dimethylformamide,
Amide solvents such as dimethylimidazolidinone; sulfur solvents such as dimethyl sulfoxide and sulfolane; nitro solvents such as nitromethane and nitroethane; ether solvents such as diglyme and tetrahydrofuran; ketone solvents such as cyclohexanone and methyl ethyl ketone; acetonitrile; In addition to nitrile solvents such as pionitrile, γ-
Solvents having a relatively high dielectric constant such as butyrolactone and tetramethylurea are exemplified. Among these, N-methyl-2-pyrrolidone, dimethylimidazolidinone, and γ-butyrolactone are preferred from the viewpoint of polymerizability. These may be used alone or as a mixed solvent, and may be mixed with a solvent having a relatively low dielectric constant such as xylene or toluene.

The logarithmic viscosity of the polyamideimide resin composition of the present invention is at least 0.1 dl / g, preferably at least 0.2 dl / g, from the viewpoint of toughness, flexibility and the like. If the logarithmic viscosity is less than 0.1 dl / g, the resin becomes brittle even though it has flexibility, which is not preferable. In the present invention, the logarithmic viscosity was measured by measuring 0.5 g of the polymer to 100 m.
Dissolve in 1 N-methyl-2-pyrrolidone and measure by Ubbelohde viscosity tube.

The polyamide-imide resin composition of the present invention can be used as a polymerization solution as it is, for example, as an insulating paint or a paint for a chemical can.
Can be used as a binder for electrodes of secondary batteries such as lithium ion secondary batteries, etc., but with solvent substitution, it is relatively versatile, low boiling point solvent solution, transparency, heat resistance, flexibility Also, it can be used as a coating agent for plastics and films, an optical member such as a liquid crystal display or a thermosensitive recording medium, or an adhesive for a circuit board, utilizing the adhesiveness to various substrates.

The method for performing the above solvent substitution is not particularly limited, and a known technique such as dry spinning and wet spinning may be applied. For example, in the case of a wet method, a polyamideimide resin solution is extruded from a nozzle into a coagulation bath composed of a solvent (preferably water) which is a non-solvent of the polyamideimide resin and is miscible with the polymerization solvent, and after coagulation and desolvation, It may be dried and redissolved in a low-boiling general-purpose solvent.

The above-mentioned low-boiling general-purpose solvent is appropriately selected depending on the polymer composition. Examples thereof include ketones such as cyclohexanone, cyclopentanone, methyl ethyl ketone and methyl isobutyl ketone; ethers such as tetrahydrofuran and dioxane; , Isopropyl alcohol, butyl alcohol and other alcohols, and benzene, toluene, xylene and other hydrocarbons, and one or more kinds of mixed solvents. The solvent can be selected depending on the purpose, but the price and solubility, Most preferred from the viewpoint of safety and the like are the above-mentioned mixed solvents of alcohols and hydrocarbons.

The polyamide-imide resin composition of the present invention comprises:
It shows excellent heat resistance, chemical resistance, adhesiveness, transparency, etc. even when used as it is, but in order to impart even higher chemical resistance and high temperature adhesion, polyfunctional epoxy compounds, melamine compounds, isocyanates It is preferable to mix at least one compound selected from the group consisting of compounds.

Examples of the epoxy compound include bisphenol A, bisphenol S, and phenol novolak type epoxy resin. A polyfunctional phenol novolak-type epoxy resin is preferred from the viewpoint of crosslinking density. In this case, a curing agent or a catalyst such as an acid anhydride, an amine, or an imidazole compound can be used.

Examples of the melamine compound include trimethylol melamine, hexamethylol melamine and lower alkyl ethers thereof, and the alkyl ether of hexamethylol melamine is preferred from the viewpoint of crosslinking density and solvent solubility. In this case, acids such as p-toluenesulfonic acid and bases such as amine can be used as the catalyst.

As the isocyanate compound, for example, diphenylmethane diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, their initial condensates, adducts with trimethylolpropane, and those obtained by blocking these with phenol and the like However, when the polyamideimide resin of the present invention is used in an alcohol system, a polyfunctional blocked isocyanate is preferred. In this case, it is also possible to use a catalyst such as dibutyltin dilaurate and amines.

These compounding agents are generally used in an amount of 1 to 50 parts, preferably 3 to 20 parts, per 100 parts of polyamideimide solids.
It is preferable to add a part. If the amount is less than 1 part, the effect of the compounding agent is not sufficiently exhibited. On the other hand, if it exceeds 50 parts, the compatibility with the polyamide-imide resin is impaired, or the inherent performance of the polyamide-imide resin is impaired, which is not preferable.

The polyamide-imide resin composition of the present invention may be, depending on the intended use, other resins such as acrylic resins and polyester resins, carbon particles, inorganic fillers such as titanium oxide, silicon oxide, and calcium carbonate, dyes, pigments, and surfactants. It is also possible to add an antistatic agent such as an agent within a range that does not impair the intrinsic performance of the polyamide-imide resin of the present invention.

[0032]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. The properties of the polymers in the examples were measured by the following methods.

Logarithmic viscosity 0.5 g of the polymer was dissolved in 100 ml of N-methyl-2-pyrrolidone and measured with an Ubbelohde viscosity tube.

Glass transition temperature (Tg) A dynamic viscoelasticity measuring device manufactured by Rheology was used. In air atmosphere, heating rate 2 ° C / min, frequency 110H
z.

The elongation at break was measured using Tensilon manufactured by Toyo Baldwin Co., Ltd.
The test was performed at 25 ° C. and 65% RH at a pulling speed of 20 mm / min.

High Temperature Adhesion Force A sample placed on a hot plate was measured by 90 ° peeling.

Examples 1 to 4 Trimellitic anhydride (TMA), diphenylmethane diisocyanate (MDI), and dimer acid (DA) were charged into a reaction vessel according to the formulations shown in Table 1, respectively.
Methyl-2-pyrrolidone (NMP) with a polymer concentration of 4
After charging to 0% and reacting at 120 ° C. for about 1 hour, the temperature was raised to 180 ° C. and reacted for 5 hours. While cooling, N-methyl-2-pyrrolidone was further added to obtain each polymer solution having a solid concentration of 20%. Table 1 shows the physical properties of these polymers.

A solution of a mixture of 90 g of a carbon material having an average particle diameter of 25 μm and 60 g of N-methyl-2-pyrrolidone obtained by reacting 50 g of these polymer solutions with furfuryl alcohol and calcining was dried on a copper foil having a thickness of 12 μm. 100 film thickness
A lithium ion secondary battery having a negative electrode was prepared by applying the solution to a thickness of μm, drying and pressing at a pressure of 1 ton / cm ² . In each case, the initial charge / discharge capacity was 300 mAh /
g, and the charge / discharge efficiency after 100 cycles was as good as 85% or more.

Example 5 Polymerization was carried out using the same raw material composition as in Example 4 except that the amount of trimellitic anhydride in Example 4 was increased by 1.2 times. Table 1 shows the physical properties of this polymer. Using this polymer, a negative electrode of a lithium ion secondary battery was prepared and tested in the same manner as in Example 1, and as a result, the initial charge / discharge capacity was 300
With mAh / g or more, the charge / discharge efficiency after 100 cycles is 8
It was as good as 5% or more.

Comparative Example 1 In a reaction vessel, 192 g of trimellitic anhydride, 250 g of diphenylmethane diisocyanate, N-methyl-2-
After charging 531 g of pyrrolidone and reacting under the same conditions as in Example 1, 885 g of N-methyl-2-pyrrolidone was added to obtain a polymer solution having a solid content of 20%. Table 1 shows the physical properties of this polymer. Using this polymer solution, a negative electrode of a lithium ion secondary battery was prepared in the same manner as in Example 1 and a charge / discharge test was performed. As a result, the initial charge / discharge capacity was as low as 210 mAh / g. .

Comparative Example 2 Raw materials were charged into a reaction vessel according to the same recipe as in Example 3, and
C. for about 1 hour, and then a mixed solution of n-butanol / N-methyl-2-pyrrolidone (10/90% by weight) 9
The reaction was stopped by adding 70 g to obtain a polymer solution having a solid content of 20%. Table 1 shows the physical properties of this polymer. Using this polymer solution, an attempt was made to produce a negative electrode for a lithium ion secondary battery in the same manner as in Example 1, but the adhesion and flexibility were poor and easily peeled from the copper foil.

[0042]

[Table 1]

Example 6 A reaction vessel was charged with 58 g of trimellitic anhydride, 52 g of cyclohexanedicarboxylic acid, 229 g of isophorone diisocyanate, 1.16 g of potassium fluoride and 23 of dimer acid.
0 g (40 mol%) together with 481 g of γ-butyrolactone and reacted at 120 ° C. for 1.5 hours.
The temperature was raised to 0 ° C. and reacted for about 3 hours. 64 while cooling
1 g of ethanol was added to obtain a polymer solution having a solid content of 30%.

This polymer solution was poured into a large amount of water to coagulate, sufficiently washed, and dried. The white polymer powder was dried in a mixed solvent of ethanol / toluene (50/50% by weight) to a solid content of 25%. It dissolved so that it might become. Table 2 shows the physical properties of this polymer. 25 μl of this polymer solution
m of polyimide (Kapton manufactured by Toray Industries, Inc.) film to a dry film thickness of 20 μm, and after drying, apply 12 μm
m rolled copper foil was pressed with a press machine at 200 ° C. to obtain a copper-clad laminate. Table 2 shows the adhesion between the copper-clad laminate and the copper foil at 100 ° C. and 150 ° C.

Example 7 A reaction vessel was charged with 4.8 g of trimellitic anhydride, 4.3 g of cyclohexanedicarboxylic acid, 229 g of isophorone diisocyanate, 1.16 g of potassium fluoride, and 547 g of dimer acid together with 697 g of γ-butyrolactone. The reaction, coagulation, washing and drying were performed under the same conditions as in Example 6, and the obtained white polymer powder was redissolved in ethanol / toluene (50/50% by weight) so that the solid content concentration became 25%. Table 2 shows the physical properties of this polymer. Using this polymer solution, a copper-clad laminate was produced in the same manner as in Example 6. 100 ° C of this copper clad laminate,
Table 2 shows the adhesion to the copper foil at 150 ° C.

Examples 8-10 Epoxy resin (Epicoat 152 manufactured by Yuka Shell Co., Ltd.) (Example 8) and melamine resin (Sumimar M40S (80% solution manufactured by Sumitomo Chemical)) were added to the polymer solution prepared in Example 7.
(Example 9), Blocked isocyanate (Coronate 2507 (80% solution) manufactured by Nippon Polyurethane) (Example 1)
10) was added to 100 parts of the solid content of the polyamideimide resin, and a copper-clad laminate was prepared in the same manner as in Example 7, and then heat-treated at 100 ° C. for 20 hours. Table 2 shows the adhesion between the copper-clad laminate and the copper foil at 100 ° C. and 150 ° C.

Comparative Example 3 A reaction vessel was charged with 96 g of trimellitic anhydride, 86 g of cyclohexanedicarboxylic acid, 229 g of isophorone diisocyanate, 1.16 g of potassium fluoride and 323 g of γ-butyrolactone. Was synthesized, coagulated in water, washed, dried, and dissolved in ethanol / toluene (50/50% by weight) to a concentration of 25%. Table 2 shows the physical properties of this polymer.
An attempt was made to produce a copper-clad laminate using the polymer solution under the same conditions as in Example 7, but no adhesion was observed to the copper foil and the polyimide film.

[0048]

[Table 2]

[0049]

As described in detail above, the polyamideimide resin composition of the present invention has improved flexibility, colorability and solvent solubility without impairing the original heat resistance and chemical resistance. It is useful for coatings, adhesives, paints, binders for secondary battery electrodes, liquid crystal displays, thermal recording materials, and the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09J 163/00 C09J 163/00 175/12 175/12 179/08 179/08 B H01M 4/02 H01M 4/02 B 4 / 62 4/62 Z 10/40 10/40 Z H05K 1/03 650 H05K 1/03 650 670 670Z (72) Inventor Hiroki Yamaguchi 2-1-1 Katada, Otsu City, Shiga Prefecture, Toyobo Co., Ltd. 72) Inventor Shiro Hamamoto 2-1-1 Katata, Otsu City, Shiga Prefecture Inside Toyobo Co., Ltd. (72) Inventor Naoshi Nakajima 2-1-1 Katata, Otsu City, Shiga Prefecture Toyobo Co., Ltd.

Claims (7)

[Claims] 1. A polyamide-imide resin composition comprising a copolymer of dimer acid and having a logarithmic viscosity of 0.1 dl / g or more. 2. The polyamide-imide resin composition according to claim 1, wherein 1% by weight or more of dimer acid is copolymerized. 3. The polyamideimide resin composition according to claim 1, wherein cyclohexanedicarboxylic acid is used as a part of the acid component. 4. The polyamide-imide resin composition according to claim 1, which contains a dicyclohexylmethane residue and / or an isophorone residue as an amine residue. 5. The polyamide-imide resin composition according to claim 1, wherein at least one compound selected from the group consisting of an epoxy compound, a melamine compound and an isocyanate compound is blended. Stuff. 6. A non-aqueous electrolyte secondary battery comprising the polyamide-imide resin composition according to claim 1 as a binder for a positive electrode and / or a negative electrode. 7. A circuit board using the polyamide-imide resin composition according to claim 1 as an adhesive.