JP2003138134A - Heat-resistant resin composition, coating and aluminum substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-resistant resin composition which has a reduced organic solvent content, does not cause environmental pollution and working environment deterioration, is excellent in safety and hygiene, gives good coating characteristics and good film characteristics, and forms coated films having excellent adhesiveness without carrying out a surface treatment for improving adhesiveness to aluminum substrates, to provide a coating containing the heat- resistant resin composition as a coating film component and to provide an aluminum substrate using the composition. SOLUTION: This heat-resistant resin composition contains a water-soluble polyamideimide resin and an aluminum chelate and/or an aluminum alkoxide. The coating contains the heat-resistant resin composition as a coating film component. An aluminum substrate uses the composition.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a heat-resistant resin composition and a coating material for forming a coating film having excellent adhesion on an aluminum substrate.

[0002]

2. Description of the Related Art Polyamide-imide resin has excellent heat resistance,
It is well known that it has chemical resistance and mechanical properties, and is widely put to practical use as a paint for heat-resistant wires, a metal surface protective paint, and the like. A general method for producing a polyamide-imide resin is also known (for example, Japanese Patent Publication No. 44-19274), but since this resin is insoluble in general solvents, N-methyl-2-pyrrolidone and dimethylacetamide have been conventionally used. , Dimethylformamide, dimethylsulfoxide, and the like, which have been dissolved in expensive polar type organic solvents, have been put to practical use as an organic solvent type resin solution.

However, since these organic solvent type resin solutions release a large amount of solvent in the heating and drying processes, environmental pollution such as air pollution and water pollution, and safety such as harmfulness to human body and deterioration of working environment, etc. It is a big problem in terms of hygiene.

Further, since these organic solvents are expensive, there is a problem of economy in that the resin solution becomes expensive due to the large amount of the organic solvent used. Further, since these polar solvents are hydrophilic, there is a problem that they absorb moisture during the coating work and partially deposit the resin, or in some cases, they gel to impair the coating workability.

In recent years, interest in environmental protection has increased, and an aqueous resin solution using water as a medium instead of an organic solvent has attracted attention. Using harmless and cheap water for the medium
It is very effective not only for environmental pollution and health and safety, but also for economic efficiency. Further, if a part or all of the hydrophilic solvent is replaced with water, the composition will contain water from the beginning, so that the problem of moisture absorption can be avoided, and therefore, as described above due to moisture absorption. The drawbacks of the existing polyamide-imide composition can be eliminated.

In response to these, the development of a water-soluble polyamide-imide resin was examined and a stable manufacturing method was established (Japanese Patent Application No. 2001-138302).

At present, an example in which an aluminum base material which is lightweight and has excellent heat dissipation is used for applications such as automobile parts and food-related appliances is increasing. However, when a polyamide-imide resin heat-resistant paint is applied to an aluminum base material, the adhesion between the coating film and the aluminum base material is difficult, and the aluminum base material is generally physically (such as polished) to improve the adhesion. , Chemical (etching with acid, alkali, etc.)
The surface treatment is performed by various methods to form irregularities on the surface of the base material, or phosphate treatment or chromate treatment is applied to form a chemical conversion film for coating. For this reason, there are problems such as a complicated coating process, an increase in cost, and pollution control regarding the treatment of waste materials, and there is an increasing need to omit the surface treatment of the aluminum base material.

[0008]

The object of the present invention is to reduce the content of organic solvent, to prevent environmental pollution and deterioration of working environment, to be advantageous in terms of safety and hygiene, and to improve the characteristics of paint and coating film. A heat-resistant resin composition that is good and that forms a coating film having excellent adhesion without surface treatment for improving adhesion to an aluminum base material, and a coating composition using this as a coating film component And to provide an aluminum substrate using this composition.

[0009]

The present invention relates to the following. (1) A heat-resistant resin composition containing a water-soluble polyamideimide resin and an aluminum chelate and / or an aluminum alkoxide. (2) (A) a polyamideimide resin obtained by reacting a diisocyanate compound or a diamine compound with a tribasic acid anhydride or tribasic acid anhydride chloride in a basic polar solvent; and (B) a basic compound, ( C) Water and (D)
The heat-resistant resin composition according to (1), which comprises an aluminum chelate and / or an aluminum alkoxide. (3) The acid value of the basic compound of the component (B) combined with the carboxyl group contained in the polyamideimide resin of the component (A) and the carboxyl group obtained by ring-opening the acid anhydride group in the polyamideimide resin. The heat-resistant resin composition according to (1) or (2), which is blended in an amount of 1 to 20 equivalents. (4) The heat resistance according to (1) or (2), wherein the water of the component (C) is blended in an amount of 5 to 99% by weight based on the total amount of the components (A), (B) and (C). Resin composition. (5) The number average molecular weight of the polyamide-imide resin is 5,0.
An acid value of 0 to 50,000 and a combined carboxyl group and a carboxyl group obtained by ring-opening an acid anhydride group is 1
The heat resistant resin composition according to any one of (1) to (4), which is 0 to 100. (6) The heat resistant resin composition according to any one of (1) to (4), wherein the basic compound as the component (B) is an alkylamine or an alkanolamine. (7) An aluminum chelate and / or an aluminum alkoxide is contained in an amount of 0.1 to 10% by weight based on 100% by weight of a polyamide-imide resin (1) or (2).
The heat-resistant resin composition as described. (8) A paint comprising the heat resistant resin composition according to any one of (1) to (7) as a coating film component. (9) An aluminum substrate on which the heat resistant resin composition according to any one of (1) to (8) is applied and cured.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The polyamide-imide resin used in the present invention preferably has a repeating structural unit represented by the general formula (I).

[0011]

[Chemical 1] [In the formula, R¹Represents a trivalent organic group, R^TwoIs divalent
Represents a machine base, and n represents an integer. ] R¹Is a trivalent C6-C20 trivalent aromatic ring.
Organic groups are preferred, R ^TwoAs a carbon with an aromatic ring
A divalent organic group of the number 6 to 20 is preferable. n is a repeating structure
R is the number of building units (I)¹And R^TwoBy the structure of
Although different, it is generally preferred to be 10-200.
Such a polyamide-imide resin is used in a basic polar solvent.
With diisocyanate compound or diamine compound and tribasic
By reacting with acid anhydride or tribasic acid chloride
Obtainable. As the basic polar solvent, N-methyl ether is used.
It is preferable to use a high boiling point solvent such as ru-2-pyrrolidone
Yes. The amount of diisocyanate used is not particularly limited.
Total amount of tri- or diamine compound and tribasic acid anhydride 1
It is preferable to set 100 to 500% by weight with respect to 00% by weight.
Good The reaction temperature is usually 80 to 180 ° C.

The diisocyanate compound or diamine compound and the tribasic acid anhydride or tribasic acid anhydride chloride are
Preference is given to using aromatic compounds in each case. Representative compounds used in the above production method are listed below. First, examples of the diisocyanate compound include 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, 3,3′-diphenylmethane diisocyanate, and paraphenylene diisocyanate.
As the diamine, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone,
3,3'-diaminodiphenyl sulfone, xylylenediamine, phenylenediamine and the like can be mentioned.

The tribasic acid anhydride includes trimellitic acid anhydride and the like, and the tribasic acid chloride includes trimellitic acid anhydride chloride and the like. When synthesizing the polyamide-imide resin, dicarboxylic acid, tetracarboxylic dianhydride and the like can be simultaneously reacted within a range that does not impair the characteristics of the polyamide-imide resin. Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, adipic acid and the like, and examples of the tetracarboxylic acid dianhydride include pyromellitic dianhydride, benzophenonetetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride and the like. Is mentioned.

The amount of the diisocyanate compound or diamine compound, tribasic acid anhydride or tribasic acid anhydride chloride, and dicarboxylic acid and tetracarboxylic dianhydride, which are optionally used, depends on the polyamideimide resin to be produced. From the viewpoint of the molecular weight and the degree of cross-linking, the diisocyanate compound or the diamine compound is preferably 0.8 to 1.1 mol based on 1.0 mol of the total amount of the acid component, and 0.95.
To 1.08 mol is more preferable, and especially 1.
It is preferable to use 0 to 1.08 mol. Moreover, it is preferable that the total amount of the dicarboxylic acid and the tetracarboxylic dianhydride in the acid component is used in the range of 0 to 50 mol%.

The number average molecular weight of the polyamide-imide resin is sampled at the time of resin synthesis and measured by gel permeation chromatograph (GPC) using a calibration curve of standard polystyrene. It is controlled within the above range by continuing.

The polyamide-imide resin used in the present invention preferably has a number average molecular weight of 5,000 to 50,000. When the number average molecular weight is less than 5,000, various properties such as heat resistance and mechanical properties of the coating film when formed into a coating film tend to be deteriorated. When dissolved in a solvent, the viscosity increases,
Workability during painting tends to be poor. From this, the number average molecular weight is preferably 10,000 to 30,000, and particularly preferably 15,000 to 25,000.

The acid value of the combined carboxyl group obtained by ring-opening the carboxyl group and the acid anhydride group is 10 to 100.
Is preferable, and when it is less than 10, the carboxyl group that reacts with the basic compound is insufficient, so that it becomes difficult to solubilize water, and when it exceeds 100, the heat-resistant resin composition finally obtained is a gel over time. It is easy to convert. From this, it is more preferable that the acid value of the combined carboxyl group obtained by ring-opening the carboxyl group and the acid anhydride group is 20 to 80, particularly preferably 30 to 60.

The acid value obtained by combining the carboxyl group of the polyamideimide resin and the carboxyl group obtained by ring-opening the acid anhydride group can be obtained by the following method. First, take about 0.5g of polyamide-imide resin and add 1,4-
About 0.15 g of diazabicyclo [2,2,2] octane
In addition, about 60 g of N-methyl-2-pyrrolidone and about 1 ml of ion-exchanged water are added, and the mixture is stirred until the polyamideimide resin is completely dissolved. 0.05 mol /
Using an ethanolic potassium hydroxide solution, titration is carried out with a potentiometric titrator to obtain an acid value in which the carboxyl group of the polyamideimide resin and the carboxyl group obtained by ring-opening the acid anhydride group are combined.

In the present invention, examples of the basic compound include triethylamine, tributylamine, triethylenediamine, alkylamines such as N-methylmorpholine, alkylaniline such as methylaniline and dimethylaniline, monoethanolamine, diethanolamine, triethanolamine, Dipropanolamine, tripropanolamine, N-ethylethanolamine, N, N-
Alkanolamines such as dimethylethanolamine, cyclohexanolamine, N-methylcyclohexanolamine and N-benzylethanolamine are suitable, but other basic compounds such as caustic alkalis such as sodium hydroxide and potassium hydroxide. Alternatively, ammonia water or the like may be used without any particular limitation. Preferably,
Triethylamine, N-methylmorpholine, triethylenediamine, N, N-dimethylethanolamine are used.

The basic compound is used in an amount of 1 to 20 equivalents based on the combined acid value of the carboxyl group and the ring-opened acid anhydride group contained in the polyamideimide resin obtained by the reaction in the above organic solvent. Used. If it is less than 1 equivalent, it becomes difficult to make the resin water-soluble, and if it exceeds 20 equivalents, hydrolysis of the resin is accelerated, and viscosity or characteristic deterioration may occur due to long-term storage. From this, it is preferable that the amount is 2 to 10 equivalents based on the combined acid value of the carboxyl group obtained by ring-opening the carboxyl group and the acid anhydride group, and 3 to 8 is preferable.
It is particularly preferable that the amount is equivalent.

The basic compound forms a salt with the carboxyl group at the terminal of the polyamide-imide resin to become a hydrophilic group. The salt formation may be carried out in the presence of water, or the basic compound may be added and then water may be added. The temperature at which the salt is formed is 0 ° C to 200 ° C, preferably 40 ° C to 13 ° C.
It is carried out in the range of 0 ° C.

Depending on the type and amount of the basic compound and the method of adding water, the form of the obtained aqueous resin composition may be an emulsion, a translucent solution, a transparent solution, etc., but the storage stability,
From the viewpoint of coating workability, a semitransparent or transparent solution is preferable. Ion-exchanged water is preferably used as the water, and is preferably 5 to 99% by weight, more preferably 20% by weight based on the total amount of the components (A), (B) and (C).
-60 wt% is compounded. If the blending amount is less than 5% by weight, the amount of water contained is small, so that it is not generally called as a water-soluble polymer, and if it exceeds 99% by weight, it tends to fail as a coating material.

Examples of the aluminum chelate used in the present invention include aluminum acetylacetonate to which acetylacetone is applied, and examples of the aluminum alkoxide include aluminum ethoxide and aluminum isopropoxide (all manufactured by Wako Pure Chemical Industries, Ltd.). The aluminum chelate and the aluminum alkoxide may be used in combination.

The amount of the aluminum chelate and / or the aluminum alkoxide used is the polyamide-imide resin 1
The range is 0.1 to 10% by weight with respect to 00% by weight,
It is preferably 1 to 5% by weight. The amount of aluminum chelate and / or aluminum alkoxide used is 0.
If it is less than 1% by weight, the adhesiveness of the coating film will decrease, and 10% by weight
If it exceeds, the heat resistance becomes poor.

There are no particular restrictions on the method of adding the aluminum chelate and / or aluminum alkoxide to the polyamideimide resin. For example, 100% by weight of the aluminum chelate and / or aluminum alkoxide may be added to a base such as dimethylformamide or N-methyl-2-pyrrolidone. There is a method in which the polar solvent is dissolved in 900 to 4000% by weight and the solution is added to the polyamideimide resin solution.

The heat-resistant resin composition thus obtained is diluted to an appropriate concentration as needed when it is used.
As a diluting solvent, in addition to polar solvents such as water, dimethylformamide, dimethylacetamide, dimethylsulfoxide and N-methyl-2-pyrrolidone, as a cosolvent,
Polyols, their lower alkyl ether compounds, acetyl compounds, etc. may be used. For example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, glycerin, trimethylolpropane, isopropyl alcohol, or their monomethyl ether compound, monoethyl ether, monoisopropyl ether compound, monobutyl ether compound,
Dimethyl ether compounds and their monoacetyl compounds are used.

The heat-resistant resin composition obtained by the production method of the present invention is excellent in various properties such as heat resistance, electric insulation, abrasion resistance and chemical resistance, and can be used in coil impregnated varnish, wire enamel, varnish cloth and the like. It can be mixed with an electrical insulating varnish, a pigment, a filler or the like and used for a heat resistant electrical insulating coating material or a surface finish. Particularly, it is preferable as a coating film component of paint.

[0028]

EXAMPLES Next, examples of the present invention will be described, but it is needless to say that the present invention is not limited to these examples and includes many other embodiments based on the gist of the invention. .

Example 1 1106.2 g of trimellitic anhydride, 1455.8 g of 4,4-diphenylmethane diisocyanate and 2562.0 g of N-methyl-2-pyrrolidone were placed in a flask equipped with a thermometer, a stirrer and a condenser, and dried. The temperature was gradually raised to 130 ° C. over about 2 hours while stirring in the nitrogen stream. The temperature was kept at 130 ° C while paying attention to the rapid foaming of carbon dioxide gas generated by the reaction, and the heating was continued for about 6 hours and then the reaction was stopped to obtain a polyamideimide resin solution.

The polyamide-imide resin solution has a nonvolatile content (200 ° C.-2 h) of about 50% by weight and a viscosity (30 ° C.).
Was about 85.0 Pa · s. The number average molecular weight of the polyamide-imide resin was about 17,000, and the acid value of the combined carboxyl group obtained by ring-opening the carboxyl group and the acid anhydride group was about 40. The number average molecular weight was measured under the following conditions. Model: Hitachi L6000 Detector: Hitachi L4000 type UV Wavelength: 270 nm Data processor: ATT 8 Column: Gelpack GL-S300MDT-5 × 2 Column size: 8 mmφ × 300 mm Solvent: DMF / THF = 1/1 (liter) + phosphorus Acid 0.06M
+ Lithium bromide 0.06M Sample concentration: 5 mg / 1 ml Injection volume: 5 μl Pressure: 49 kgf / cm ² (4.8 × 10 ⁶ Pa) Flow rate: 1.0 ml / min

This polyamide-imide resin solution 2,700
g into a flask equipped with a thermometer, stirrer and condenser,
Gradually raise the temperature while stirring in a dry nitrogen stream 5
Raised to 0 ° C. When the temperature reached 50 ° C, 447.1 g (4 equivalents) of triethylamine was added, and after sufficiently stirring while maintaining the temperature at 50 ° C, ion-exchanged water was gradually added while stirring. Finally, deionized water is 1348.8g
(30% by weight), and a transparent and uniform heat resistant resin composition was obtained. 15% by weight of an aluminum isopropoxide solution (Wako Pure Chemical Industries, Ltd., N-methyl-2-pyrrolidone solution, solid content concentration 10% by weight) was added to 100% by weight of the heat-resistant resin composition produced by the above method, A heat resistant resin composition was obtained.

Example 2 382.9 g of trimellitic anhydride, 503.9 g of 4,4'-diphenylmethane diisocyanate, N-methyl-
886.8 g of 2-pyrrolidone was placed in a flask equipped with a thermometer, a stirrer, and a condenser, and the temperature was gradually raised to 80 ° C over about 1 hour while stirring in a dry nitrogen stream. The temperature was kept at 80 ° C. while paying attention to the rapid foaming of carbon dioxide gas generated by the reaction, the heating was continued for about 7 hours from the start of heating, and then the reaction was stopped to obtain a polyamideimide resin solution.
The nonvolatile content of this polyamide-imide resin solution (200 ° C-
2h) is about 50% by weight and the viscosity (30 ° C) is about 80.0
It was Pa · s. The number-average molecular weight of the polyamide-imide resin was about 15,000, and the combined acid value of the carboxyl groups obtained by ring-opening the carboxyl group and the acid anhydride group was about 50. 200g of this polyamide-imide resin solution
Was placed in a flask equipped with a thermometer, a stirrer, and a condenser, and the temperature was gradually raised to 90 while stirring in a dry nitrogen stream.
Raised to ℃. When the temperature reached 90 ° C, 70.8 g (8 equivalents) of N-methylmorpholine was added, and the mixture was sufficiently stirred while maintaining the temperature at 90 ° C, and then ion-exchanged water was gradually added while stirring. Finally, 180.5 g (4
0% by weight) to obtain a transparent and uniform heat resistant resin composition. A heat-resistant resin composition was prepared by adding 5% by weight of an aluminum acetylacetonate solution (manufactured by Wako Pure Chemical Industries, dimethylformamide solution, solid content concentration: 5% by weight) to 100% by weight of the heat-resistant resin composition produced by the above method. Got

Example 3 233.8 g of trimellitic anhydride, 98.0 g of benzophenone tetracarboxylic acid anhydride, 384.6 g of 4,4'-diphenylmethane diisocyanate, N-methyl-2-
1671.6 g of pyrrolidone was placed in a flask equipped with a thermometer, a stirrer, and a cooling tube, and the temperature was gradually raised to 120 ° C. over about 1 hour while stirring in a dry nitrogen stream. While paying attention to the rapid bubbling of carbon dioxide gas generated by the reaction, gradually raise the temperature to 150 ° C and start heating 5
After continuing heating for a period of time, the reaction was stopped and a polyamideimide resin solution was obtained. The nonvolatile content (200 ° C-2h) of this polyamide-imide resin solution is about 30% by weight, and the viscosity (30
C.) was about 2.1 Pa.s. Further, the number average molecular weight of the polyamide-imide resin was about 23,000, and the acid value of the combined carboxyl group and acid anhydride group was about 30. 200g of this polyamide-imide resin solution is thermometer,
The mixture was placed in a flask equipped with a stirrer and a condenser, and the temperature was gradually raised to 110 ° C while stirring in a dry nitrogen stream. When the temperature reached 110 ° C, 17.6 g (6 equivalents) of N, N-dimethylethanolamine was added, and the temperature was 110 ° C.
After sufficiently stirring the mixture while keeping it at 1, ion-exchanged water was gradually added while stirring. Finally, the ion-exchanged water was 217.
The amount was 6 g (50% by weight) to obtain a transparent and uniform heat-resistant resin composition. Aluminum acetylacetonate solution (manufactured by Wako Pure Chemical Industries, dimethylformamide solution, 100% by weight of the heat-resistant resin composition prepared by the above method)
A solid content concentration of 10% by weight) was mixed with 50% by weight to obtain a heat resistant resin composition.

Comparative Example 1 876.9 g of trimellitic anhydride, 1153.8 g of 4,4'-diphenylmethane diisocyanate and 4,738.3 g of N-methyl-2-pyrrolidone were used as a thermometer and a stirrer.
Put in a flask equipped with a cooling tube, gradually heat up for about 1 hour while stirring in a dry nitrogen stream, and raise the temperature to 110 ° C.
Raised. The temperature was gradually raised to 120 ° C while paying attention to the rapid foaming of carbon dioxide gas generated by the reaction. After continuing heating for about 8 hours from the start of heating, the reaction was stopped to obtain a polyamideimide resin solution. The nonvolatile content (200 ° C-2h) of this polyamide-imide resin solution is about 30% by weight.
The viscosity (30 ° C.) was about 1.8 Pa · s. The number average molecular weight of the polyamide-imide resin is about 21,0.
At 00, the acid value of the combined carboxyl group obtained by ring-opening the carboxyl group and the acid anhydride group was about 35. 2000 g of this polyamide-imide resin solution was mixed with a thermometer, a stirrer,
The flask was placed in a flask equipped with a cooling tube, and the temperature was gradually raised to 90 ° C. with stirring in a dry nitrogen stream. 90
When the temperature reached ℃, N-methylmorpholine was added to 365.7.
g (7 equivalents) was added, and the mixture was thoroughly stirred while maintaining the temperature at 90 ° C., and then ion-exchanged water was gradually added with stirring. Finally, ion-exchanged water was added to 1577.1 g (40% by weight) to obtain a transparent and uniform heat-resistant resin composition.

Test Example The heat-resistant resin composition described in Examples 1, 2 and 3 and Comparative Example 1 was applied to a substrate (aluminum plate JIS H 4000, thickness 1 mm, unpolished) and then at 250 ° C. for 30 minutes. After baking, a coated film plate with a film thickness of 10 μm was prepared, and the initial and P.
The adhesion after deterioration of CT was measured. Adhesion is JIS K
Measured according to 5400 (%, cross-cut residual rate),
PCT is 50 and 10 under the condition of 121 ° C and 2.2 atm.
The measurement was performed after 0 hours.

The heat resistance of the coating film characteristics was tested by the following method. The heat-resistant resin composition described in Examples 1, 2 and 3 and the polyamideimide resin solution described in Comparative Example 1 were applied on a glass plate and heated at 100 ° C. for 10 minutes, and further 400
The coating was obtained by heating at 15 ° C for 15 minutes to cure and peeling from the glass plate. Thermogravimetric analysis (sample amount 10
mg, temperature rising rate 10 ° C./min, nitrogen 30 ml / min), and the heat resistance of each coating film was compared. The test results are shown in Table 1.

[0037]

[Table 1]

From Table 1, the coating films obtained from the heat-resistant resin compositions obtained in Examples 1, 2 and 3 were compared with the coating films obtained from the heat-resistant resin composition of Comparative Example 1 by P.C. .T. It can be seen that the adhesiveness after deterioration is excellent.

[0039]

EFFECTS OF THE INVENTION The water-soluble polyamideimide resin heat-resistant resin composition of the present invention reduces the amount of organic solvent by containing ion-exchanged water, which is advantageous for safety and hygiene aspects such as environmental pollution and deterioration of working environment. It is also suitable for various heat resistant paint applications such as insulating coatings on various base materials as well as protective coats because it has good paint and coating properties and has excellent adhesion to aluminum base materials. Can be used for.

Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09D 179/08 C09D 179/08 B

Claims (8)

[Claims] 1. A polyamideimide resin obtained by reacting a diisocyanate compound or a diamine compound with a tribasic acid anhydride or a tribasic acid anhydride chloride in (A) a basic polar solvent, and (B) a basic compound. , (C) water and (D) aluminum chelate and / or aluminum alkoxide. 2. An acid value in which the basic compound of the component (B) is a combination of the carboxyl group contained in the polyamideimide resin of the component (A) and the carboxyl group obtained by ring-opening the acid anhydride group in the polyamideimide resin. The heat resistant resin composition according to claim 1, which is blended in an amount of 1 to 20 equivalents. 3. The heat resistant resin according to claim 1, wherein the water as the component (C) is blended in an amount of 5 to 99% by weight based on the total amount of the components (A), (B) and (C). Composition. 4. A polyamideimide resin having a number average molecular weight of 5,000 to 50,000 and an acid value of 10 to 100 inclusive of a carboxyl group and a carboxyl group obtained by ring-opening an acid anhydride group. Item 5. A heat resistant resin composition according to item 1 or 2. 5. The basic compound as the component (B) is an alkylamine or an alkanolamine.
The heat-resistant resin composition as described. 6. The heat-resistant resin composition according to claim 1, wherein the component (D), an aluminum chelate and / or an aluminum alkoxide, is added in an amount of 0.1 to 10% by weight based on 100% by weight of the heat-resistant resin composition. object. 7. A paint comprising the heat resistant resin composition according to claim 1, 2, 3, 4, 5 or 6 as a coating film component. 8. An aluminum substrate on which the heat resistant resin composition according to claim 1, 2, 3, 4, 5, 6 or 7 is applied and cured.