JP2010215785A - Heat-resistant polyamideimide resin and seamless tubular body, coating film, coating film plate, and heat-resistant coating material using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-resistant polyamideimide resin which may form a coating film and seamless tubular body excellent in elongation, and to provide a seamless tubular body, coating film, coating film plate and heat-resistant coating material using the same. <P>SOLUTION: The heat-resistant polyamideimide resin is obtained by reacting (a) a polycarboxylic acid anhydride of trivalent or more and having an acid anhydride group and a carboxyl group, (b) 4,4'-(m-phenylene diisopropylidene) imido dicarboxylic acid expressed by formula (I) and (c) an aromatic polyisocyanate in a basic polar solvent. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a heat-resistant polyamide-imide resin that is a polyamide-imide copolymer.
The present invention also relates to a seamless tubular body, a coating film, a coating plate, and a heat-resistant coating material suitable for use in the transmission of rotational motion in various precision devices such as electric / electronic devices and electronic copying machines using the same.

  For example, pyromellitic dianhydride and 4,4'-diaminodiphenyl ether are used as a polyimide resin for seamless tubular bodies for the purpose of transmitting rotational motion in various precision equipment such as electrical / electronic equipment and electronic copying machines. Polyimide resin obtained from Tell, polyimide resin obtained from 3,3'-4,4'-biphenyltetracarboxylic dianhydride and p-phenylene cyamine, especially excellent mechanical properties (tear strength / elasticity) Rate / elongation rate), it is applied as the mainstream. However, in recent years, needs for cost reduction are increasing, and polyamide imide resin has been attracting attention from the viewpoint of low cost and the same imide resin.

  In general, polyamideimide resin is excellent in heat resistance, chemical resistance, and solvent resistance. Therefore, it is especially heat resistant as a coating film component of various varnish coatings for enameled wires and for forming protective coating films on various substrates. It has been widely used to form protective coatings. As a conventional polyamideimide resin, for example, a polyamideimide resin obtained by reaction of diphenylmethane-4,4′-diisocyanate and trimellitic anhydride (see, for example, Patent Document 1 and Patent Document 2) is known. .

Japanese Patent Publication No. 44-019274 Japanese Patent Publication No. 45-027611

  However, the conventional polyamide-imide resin is difficult to apply because the elongation rate of the coating film, which greatly affects the life of the seamless tubular body, is significantly inferior to that of the polyimide resin. Not reached.

  In view of the above, the present invention provides a heat-resistant polyamide-imide resin that can form a coating film and a seamless tubular body excellent in elongation. In addition, the present invention provides a seamless tubular body, a coating film, a coating film plate, and a heat-resistant paint that are molded using this heat-resistant polyamideimide resin.

The present invention relates to the following.
The present invention relates to [1] (a) a trivalent or higher polycarboxylic acid anhydride having an acid anhydride group and a carboxyl group, and (b) 4,4 ′-(m-phenylenediisopropylate represented by the formula (I). The present invention relates to a heat-resistant polyamide-imide resin obtained by reacting (redene) imidodicarboxylic acid and (c) an aromatic polyisocyanate in a basic polar solvent.

また、本発明は、［２］前記（ａ）成分及び前記（ｂ）成分の配合量が、当量比で（ｂ）成分／（ａ）成分＝０．０１／０．９９〜０．６０／０．４０である上記［１］に記載の耐熱性ポリアミドイミド系樹脂に関する。
また、本発明は、［３］（ｃ）芳香族ポリイソシアネートと、（ａ）ポリカルボン酸無水物及び（ｂ）式（Ｉ）で示される４，４′-（ｍ-フェニレンジイソプロピリデン）イミドジカルボン酸とのイソシアネート基とカルボキシル基との配合量が、当量比で全イソシアネート基／全カルボキシル基＝０．８〜１．４で、数平均分子量が１００００〜５００００である上記［１］又は［２］に記載の耐熱性ポリアミドイミド系樹脂に関する。
また、本発明は、［４］耐熱性ポリアミドイミド系樹脂により形成された塗膜の伸び率が、９０％以上、引張強度が、１００ＭＰａ以上（２５℃）である上記［１］ないし［３］のいずれかに記載の耐熱性ポリアミドイミド系樹脂に関する。

The present invention also provides [2] the blending amount of the component (a) and the component (b) in an equivalent ratio of (b) component / (a) component = 0.01 / 0.99 to 0.60 / The heat-resistant polyamide-imide resin according to [1], which is 0.40.
The present invention also provides [3] (c) aromatic polyisocyanate, (a) polycarboxylic acid anhydride, and (b) 4,4 ′-(m-phenylenediisopropylidene) represented by the formula (I). [1] or [1] above, wherein the amount of the isocyanate group and carboxyl group in the imidodicarboxylic acid is equal to the total isocyanate group / total carboxyl group = 0.8 to 1.4 in an equivalent ratio, and the number average molecular weight is 10,000 to 50,000. The heat-resistant polyamide-imide resin according to [2].
The present invention also provides [4] the above [1] to [3], wherein the coating film formed of the heat-resistant polyamide-imide resin has an elongation percentage of 90% or more and a tensile strength of 100 MPa or more (25 ° C.). The heat-resistant polyamide-imide resin according to any one of the above.

The present invention also relates to [5] a seamless tubular body formed using the heat-resistant polyamideimide resin according to any one of [1] to [4].
The present invention also relates to [6] a coating film formed by applying and heating the heat-resistant polyamideimide resin according to any one of [1] to [4].
The present invention also relates to [7] a coated plate having a coated film formed by applying and heating the heat-resistant polyamideimide resin according to any one of [1] to [4] on the surface.
The present invention also relates to [8] a heat resistant paint containing the heat resistant polyamide-imide resin according to any one of [1] to [4] and an organic solvent.

  According to the heat-resistant polyamide-imide resin of the present invention, it becomes possible to produce a coating film having excellent tensile strength and elongation (breaking elongation), and rotational motion in precision equipment such as electrical / electronic equipment and electronic copying machines. Not only the seamless tubular body for transmission, but also high functionality of various heat-resistant coatings such as coatings, coatings, and heat-resistant coatings is possible, which is useful for improving reliability.

The polycarboxylic acid component (a) used in the production of the heat-resistant polyamideimide resin in the present invention contains, in one molecule, [an acid anhydride group that reacts with an isocyanate group to form an imide bond] and / or “isocyanate”. There is no particular limitation as long as it is a compound having a total of two or more carboxyl groups that react with a -to group to form an amide bond], or a mixture thereof, and an acid anhydride as an essential component. Examples of the trivalent or higher polycarboxylic acid anhydride having an acid anhydride group and a carboxyl group include aromatic tricarboxylic acid anhydrides represented by the general formulas (II) and (III).
In view of heat resistance, cost, etc., trimellitic anhydride is particularly preferable.

（但し、一般式（II）、(III)中、Ｒ^１は、水素、炭素数１〜１０のアルキル基又はフェニル基を示し、Ｙは−ＣＨ_２−、−ＣＯ−、−ＳＯ_２−、又は−Ｏ−を示す。）
また、（ａ）成分のポリカルボン酸成分としては、これらの他に必要に応じて、テトラカルボン酸二無水物、脂肪族ジカルボン酸、芳香族ジカルボン酸等を併用することができる。
テトラカルボン酸二無水物として、ピロメリット酸二無水物、３，３'，４，４'−ベンゾフェノンテトラカルボン酸二無水物、３，３′，４，４′-ビフェニルテトラカルボン酸二無水物、２，２′，３，３′-ビフェニルテトラカルボン酸二無水物、２，３，３′，４′-ビフェニルテトラカルボン酸二無水物３，３′，４，４′-ジフェニルスルホンテトラカルボン酸二無水物、エチレングリコールビスアンドヒドロトリメリテ-ト、２，２-ビス（２、５-ジカルボキシフェニル）プロパンニ無水物、１，１-ビス（２，３-ジカルボキシフェニル）エタン酸二無水物、１，１-ビス（３，４-ジカルボキシフェニル）スルホンニ無水物、１，２，５，６-ナフタレンテトラカルボン酸二無水物、２，３，５，６-ピリジンテトラカルボン酸二無水物、１，４，５，８-ナフタレンテトラカルボン酸二無水物、３，４，９，１０-ペリレンテトラカルボン酸二無水物、４，４'-スルホニルジフタル酸二無水物、ｍ-ターフェニル-３，３'，４，４'-テトラカルボン酸二無水物、４，４'-オキシジフタル酸二無水物、１，１，１，３，３，３-ヘキサフルオロ-２，２-ビス（２，３-又は３，４-ジカルボキシフェニル）プロパン二無水物、１，３-ビス（３，４-ジカルボキシルフェニル）-１，１，３，３-テトラメチルジシロキサン二無水物、ブタンテトラカルボン酸二無水物、ビシクロ-［２，２，２］-オクト-７-エン-２：３：５：６-テトラカルボン酸二無水物等が例示される。
脂肪族ジカルボン酸として、コハク酸、グルタル酸、アジピン酸、アゼライン酸、スベリン酸、セバシン酸、デカン二酸、ドデカン二酸、ダイマー酸等が挙げられる。
芳香族ジカルボン酸として、イソフタル酸、テレフタル酸、フタル酸、ナフタレンジカルボン酸、オキシジ安息香酸等が挙げられ、これらは併用することができる。また、これらポリカルボン酸成分の誘導体も使用することができる。
これらの酸や酸無水物の使用量は、全酸成分の５０当量％以下とすることが好ましい。

(In the general formulas (II) and (III), R ¹ represents hydrogen, an alkyl group having 1 to 10 carbon atoms, or a phenyl group, and Y represents —CH ₂ —, —CO—, —SO ₂ —, Or -O- is shown.)
Moreover, as a polycarboxylic acid component of (a) component, tetracarboxylic dianhydride, aliphatic dicarboxylic acid, aromatic dicarboxylic acid, etc. can be used together as needed besides these.
As tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride, 2,3,3', 4'-biphenyltetracarboxylic dianhydride 3,3 ', 4,4'-diphenylsulfonetetracarboxylic Acid dianhydride, ethylene glycol bisandhydrotrimellitate, 2,2-bis (2,5-dicarboxyphenyl) propane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane acid Anhydride, 1,1-bis (3,4-dicarboxyphenyl) sulfone dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,3,5,6-pyridinetetracarboxylic acid Anhydride, 1 4,5,8-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 4,4′-sulfonyldiphthalic dianhydride, m-terphenyl-3, 3 ', 4,4'-tetracarboxylic dianhydride, 4,4'-oxydiphthalic dianhydride, 1,1,1,3,3,3-hexafluoro-2,2-bis (2,3 -Or 3,4-dicarboxyphenyl) propane dianhydride, 1,3-bis (3,4-dicarboxylphenyl) -1,1,3,3-tetramethyldisiloxane dianhydride, butanetetracarboxylic acid Examples of the dianhydride include bicyclo- [2,2,2] -oct-7-ene-2: 3: 5: 6-tetracarboxylic dianhydride.
Examples of the aliphatic dicarboxylic acid include succinic acid, glutaric acid, adipic acid, azelaic acid, suberic acid, sebacic acid, decanedioic acid, dodecanedioic acid, and dimer acid.
Examples of the aromatic dicarboxylic acid include isophthalic acid, terephthalic acid, phthalic acid, naphthalenedicarboxylic acid, and oxydibenzoic acid, and these can be used in combination. In addition, derivatives of these polycarboxylic acid components can also be used.
The amount of these acids and acid anhydrides used is preferably 50 equivalent% or less of the total acid component.

  As the component (b) used in the present invention, 4,4 ′-(m-phenylenediisopropylidene) imide dicarboxylic acid, which is the dicarboxylic acid component represented by the formula (I), is represented by the following formula (IV). 4,4 '-(m-phenylenediisopropylidene) dianiline and the polycarboxylic acid component are reacted in a solvent-free or organic solvent.

  The mixing ratio of the carboxylic acid component represented by the general formulas (II) and (III) and the 4,4 ′-(m-phenylenediisopropylidene) dianiline component represented by the formula (IV) is an acid anhydride in an equivalent ratio. It is preferable that the physical group (acid group) / amine group is 1.01 or more, more preferably 1.5 to 2.5, and 1.9 to 2.1. More preferably.

The reaction can be easily performed without solvent or in the presence of an organic solvent. The reaction temperature is preferably 60 to 100 ° C., and the reaction time can be appropriately selected depending on the scale of the batch, the reaction conditions employed, and the like.
Examples of organic solvents that can be used include ketone solvents (methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ester solvents (ethyl acetate, butyl acetate, γ-butyrolactone, etc.), ether solvents (diethylene glycol dimethyl ether, triethylene glycol dimethyl ether). Etc.), cellosolve solvents (butyl cellosolve acetate, ethyl cellosolve acetate, methyl cellosolve acetate, etc.), aromatic hydrocarbon solvents (toluene, xylene, p-cymene, etc.), tetrahydrofuran, dioxane, N-methyl-2-pyrrolidone, N , N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide and the like.

  There is no restriction | limiting in particular as an aromatic polyisocyanate compound of (c) component in this invention, What is represented by the following general formula (V) can be used.

[一般式（Ｖ）中、Ｘは、炭素数１〜１８のアルキレン基又はフェニレン基等のアリーレン基（これはメチル基等の低級アルキル基を置換基として有していてもよい）を示す]

[In general formula (V), X represents an arylene group such as an alkylene group having 1 to 18 carbon atoms or a phenylene group (which may have a lower alkyl group such as a methyl group as a substituent)]

  Examples of the diisocyanates represented by the general formula (V) include diphenylmethane-2,4′-diisocyanate, 3,2′- or 3,3′- or 4,2′- or 4,3′- or 5,2'- or 5,3'- or 6,2'- or 6,3'-dimethyldiphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- Or 4,3'- or 5,2'- or 5,3'- or 6,2'- or 6,3'-diethyldiphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3 ' -Or 4,2'- or 4,3'- or 5,2'- or 5,3'- or 6,2'- or 6,3'-dimethoxydiphenylmethane-2,4'-diisocyanate, diphenylmethane-4 , 4'-diisocyanate, benzophenone-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, diphenylsulfone-4,4 '-Diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, naphthalene-2,6-diisocyanate, 4,4'-{2,2- Various conventionally known diisocyanate compounds such as bis (4-phenoxyphenyl) propane} diisocyanate can be mentioned. These may be used alone or in admixture of two or more. Among the above polyisocyanate compounds, diphenylmethane-4,4′-diisocyanate is most preferably used in the present invention in terms of heat resistance and mechanical properties of the coating film.

  In addition to (c) aromatic polyisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, transcyclohexane-1,4-diisocyanate, hydrogenated Aliphatic or cycloaliphatic isocyanates such as m-xylylene diisocyanate and lysine diisocyanate, and tri- or higher functional polyisocyanates may be used, and those stabilized with blocking agents necessary to avoid changes over time are used. Also good.

The blending ratio of the carboxylic acid component represented by formula (I) of the component (b) and the polycarboxylic acid component of the component (a) in the present invention is an equivalent ratio of (b) component / (a) component = 0.01. /0.99-0.60/0.40, more preferably 0.1 / 0.9-0.5 / 0.5, and 0.2 / 0.8-0. A ratio of 8 / 0.2 is particularly preferable.
If the equivalent ratio is less than 0.01 / 0.99, it is difficult to increase the elongation rate of the resulting heat-resistant polyamideimide resin, and if it exceeds 0.60 / 0.40, the heat resistance of the coating film is reduced. It will drop significantly.

In addition, the isocyanate group of (c) aromatic polyisocyanate, (a) polycarboxylic acid anhydride, and (4) 4,4 '-(m-phenylenediisopropylidene) imide dicarboxylic acid represented by the formula (I) And the amount of the carboxyl group is preferably set to an equivalent ratio of all isocyanate groups / total carboxyl groups = 0.8 to 1.4, more preferably 0.9 to 1.3, It is particularly preferable that the ratio is 0.9 to 1.2.
If this ratio is less than 0.8, it is difficult to increase the molecular weight of the polyamideimide resin, and if it exceeds 1.4, the elongation at break is significantly reduced.

  The heat-resistant polyamideimide resin of the present invention is synthesized in a basic polar solvent, and N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylformamide, N, N-diethylformamide, dimethyl sulfoxide, hexamethylphosphoramide, tetramethylene sulfone and the like. From the viewpoint of economy and ease of polymerization, N-methyl-2-pyrrolidone or N, N-dimethylacetamide is preferably used. The amount used is not particularly limited, but the total amount of (a) polycarboxylic acid, (b) 4,4 ′-(m-phenylenediisopropylidene) imide dicarboxylic acid, and (c) aromatic polyisocyanate is 100 mass. The amount is preferably 100 to 900 parts by mass, more preferably 125 to 600 parts by mass, and particularly preferably 150 to 400 parts by mass.

The number average molecular weight of the heat-resistant polyamideimide resin thus obtained is preferably 10,000 to 50,000, more preferably 15,000 to 40,000, and 20,000 to 35,000 is particularly preferred.
When the number average molecular weight is less than 10,000, various properties such as the heat resistance and mechanical properties of the coating film tend to be reduced. When the number average molecular weight exceeds 50,000, the coating composition is suitable as a coating material. When dissolved in a solvent so as to have a concentration, the viscosity increases, and the workability during coating tends to be inferior.

  The number average molecular weight of the heat-resistant polyamide-imide resin is measured by sampling a reaction solution during synthesis and using a standard polystyrene calibration curve by gel permeation chromatography (GPC) to obtain the target number average molecular weight. By continuing the synthesis until the desired range can be adjusted.

  The heat-resistant polyamide-imide resin of the present invention can form a coating film having excellent tear strength, elongation rate, heat resistance, chemical resistance and solvent resistance by coating and heating. It can be used as a seamless tubular body for the purpose of transmitting rotational motion in various precision equipment such as electrical / electronic equipment and electronic copying machines, films, fibers, and other raw materials for electrical and electronic parts and mechanical parts. . For example, by applying and heating the heat-resistant polyamide-imide resin of the present invention, a coating film having an elongation (25 ° C.) of 90% or more and a tensile strength (25 ° C.) of 100 MPa or more is formed. In particular, it is preferably used for forming a seamless tubular body.

  When forming a coating film, it is normally used as a heat resistant coating containing 10 to 50% by mass, preferably 20 to 40% by mass, as the solid content of the heat resistant polyamide-imide resin of the present invention. Examples of the organic solvent that can be used in the heat resistant coating include ketone solvents (methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ester solvents (ethyl acetate, butyl acetate, γ-butyrolactone, etc.), ether solvents (diethylene glycol dimethyl ether, Triethylene glycol dimethyl ether, etc.), cellosolve solvents (butyl cellosolve acetate, ethyl cellosolve acetate, methyl cellosolve acetate, etc.), aromatic hydrocarbon solvents (toluene, xylene, p-cymene, etc.), tetrahydrofuran, dioxane, N-methyl-2 -Pyrrolidone, N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, dimethyl sulfoxide, hexamethyl Phosphoramides, such as tetramethylene sulfone.

  As a base material which forms a coating film, plate-shaped base materials, such as a glass plate, are mentioned, for example. For example, the heat-resistant polyamide-imide resin of the present invention is applied as a heat-resistant paint as described above to a plate-like surface such as a commercially available glass plate, and heated to obtain tensile strength, elongation at break, heat resistance, resistance to heat. It is possible to obtain a coated plate having a coated film excellent in chemical properties and solvent resistance on the surface. In the case of forming a seamless tubular body, the heat-resistant polyamideimide resin of the present invention or a solution thereof is poured into a stainless steel cylindrical mold, and a resin film is formed at 150 to 300 ° C. to form a resin film on the cylindrical inner surface or outer cylindrical surface. After drying with hot air for 30 to 120 minutes, a seamless tubular body can be obtained by demolding. At this time, a filler such as a conductive filler such as carbon may be further kneaded and used in the heat-resistant polyamide-imide resin.

  The heating for forming the coating film is usually performed at 150 to 300 ° C. for 30 to 120 minutes, and the heat resistant polyamide-imide resin is cured by this heating. Although the thickness of a coating film changes with uses of a coating film and there is no restriction | limiting in particular, Usually, it is 20-120 micrometers, Preferably it is 50-80 micrometers.

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

Example 1
As the synthesis of component (b), 34.5 g (0.1 mol) of 4,4 ′-(m-phenylenediisopropylidene) dianiline [trade name: Bisanline M] (manufactured by Mitsui Chemicals) and trimellitic anhydride 38.4 g (0.2 mol) and 109.4 g of N-methyl-2-pyrrolidone were charged into a flask equipped with a thermometer, stirrer and condenser, and the mixture was dried in a nitrogen stream for about 1 hour. The temperature was gradually raised to 80 ° C. and kept at 80 ° C. for 1 hour to obtain 4,4 ′-(m-phenylenediisopropylidene) imide dicarboxylic acid (0.1 mol) as component (b).
Further, in this reaction solution, 172.9 g (0.90) of trimellitic anhydride as component (a) and 254.0 g (1.015 mol) of diphenylmethane-4,4′-diisocyanate as component (c) and basic polarity N-methyl-2-pyrrolidone (640.3 g) was added as a solvent, and the temperature was raised gradually to 140 ° C. over about 4 hours, paying attention to the sudden bubbling of carbon dioxide gas generated by the reaction, followed by reaction for 7 hours. Thus, a solution of a heat-resistant polyamideimide resin having a number average molecular weight of 27,300 was obtained.
The blending ratios of component (a), component (b), and component (c) used in this reaction are as follows in terms of equivalent ratio.
(B) / (a) = 0.10 / 0.90
(C) / {(b) + (a)} = 1.015
The obtained solution was diluted with N-methyl-2-pyrrolidone to obtain a heat-resistant paint (resin concentration: 30% by mass).

(Example 2)
As the synthesis of the component (b), 4,4 ′-(m-phenylenediisopropylidene) dianiline [trade name: Bisanline M (manufactured by Mitsui Chemicals)] 103.4 g (0.3 mol) and trimellitic anhydride 115.3 g (0.6 mol) and 328.1 g of N-methyl-2-pyrrolidone were charged into a flask equipped with a thermometer, stirrer and condenser, and the mixture was dried in a nitrogen stream for about 1 hour. The temperature was gradually raised to 90 ° C. and kept at 90 ° C. for 2 hours to obtain imidodicarboxylic acid (0.3 mol) as component (b).
Further, 134.5 g (0.7 mol) of trimellitic anhydride as component (a) and 256.5 g (1.025 mol) of diphenylmethane-4,4′-diisocyanate as component (c) and N − Methyl-2-pyrrolidone (804.2 g) was charged, and the temperature was raised gradually to 145 ° C. over about 2 hours, paying attention to the sudden foaming of carbon dioxide gas generated by the reaction. A solution of heat-resistant polyamideimide resin having an average molecular weight of 32,000 was obtained.
The blending ratios of component (a), component (b), and component (c) used in this reaction are as follows in terms of equivalent ratio.
(B) / (a) = 0.30 / 0.70
(C) / {(b) + (a)} = 1.025
The obtained solution was diluted with N-methyl-2-pyrrolidone to obtain a heat-resistant paint (resin concentration: 25% by mass).

Example 3
As a synthesis of the component (b), 4,4 ′-(m-phenylenediisopropylidene) dianiline [trade name: Bisanline M (manufactured by Mitsui Chemicals)] 68.9 g (0.2 mol) and trimellitic anhydride 76 .9 g (0.4 mol) and 218.7 g of N-methyl-2-pyrrolidone were charged into a flask equipped with a thermometer, a stirrer and a condenser, and the mixture was dried in a nitrogen stream for about 1 hour. The temperature was gradually raised to 90 ° C. and kept at 90 ° C. for 2 hours to obtain an imidodicarboxylic acid (0.2 mol) as component (b).
Furthermore, 153.7 g (0.8 mol) of trimellitic anhydride as component (a) and 202.2 g (0.808 mol) of diphenylmethane-4,4′-diisocyanate as component (c) were added to this reaction solution. , 3′-Dimethylbiphenyl-4,4′-diisocyanate [trade name: TODI (manufactured by Nippon Soda Co., Ltd.)] 53.4 g (0.4 mol) and N-methyl-2-pyrrolidone 812.2 g were charged and reacted. Heat-resistant polyamide-imide resin having a number average molecular weight of 33,100 by reacting for 13 hours after gradually raising the temperature to about 145 ° C. over a period of about 2 hours, paying attention to the sudden foaming of carbon dioxide gas generated by Solution was obtained.
The blending ratios of component (a), component (b), and component (c) used in this reaction are as follows in terms of equivalent ratio.
(B) / (a) = 0.20 / 0.80
(C) / {(b) + (a)} = 1.21
The obtained solution was diluted with N-methyl-2-pyrrolidone to obtain a heat-resistant paint (resin concentration: 20% by mass).

(Comparative Example 1)
Add 192.1 g (1.0 mol) of trimellitic anhydride, 262.8 g (1.05 mol) of 4,4'-diphenylmethane diisocyanate, and 682.4 g of N-methyl-2-pyrrolidone to a thermometer, stirrer, and condenser. The mixture was placed in a equipped flask, and the mixture was gradually heated to 140 ° C. over about 5 hours in a dry nitrogen stream while paying attention to sudden foaming of carbon dioxide gas generated by the reaction. The mixture was kept at 140 ° C. for 8 hours to obtain a polyamideimide resin solution having a number average molecular weight of 27,000.
This solution was diluted with N-methyl-2-pyrrolidone to obtain a paint (resin concentration: 31% by mass).

(Comparative Example 2)
60.1 g (0.3 mol) of 4,4'-diaminodiphenyl ether, 115.3 g (0.6 mol) of trimellitic anhydride and 263.1 g of N-methyl-2-pyrrolidone were added to a thermometer, stirrer and condenser. The prepared flask was charged, and the mixture was gradually heated to 80 ° C. over about 1 hour in a dried nitrogen stream, and kept at 80 ° C. for 1 hour, and imidodicarboxylic acid (0.3 mol) was added. Obtained.
Further, in this reaction solution, 134.5 g (0.70 mol) of trimellitic anhydride as component (a) and 255.3 g (1.02 mol) of diphenylmethane-4,4′-diisocyanate as component (c) and N − Methyl-2-pyrrolidone (584.7 g) was charged, gradually increased in temperature over about 7 hours, paying attention to the sudden bubbling of carbon dioxide gas generated by the reaction, heated up to 140 ° C., and reacted for 7 hours. A solution of polyamideimide resin having a molecular weight of 27,300 was obtained.
The obtained solution was diluted with N-methyl-2-pyrrolidone to obtain a heat-resistant paint (resin concentration: 30% by mass).

(Comparative Example 3)
200.24 g (1.0 mol) of 4,4′-diaminodiphenyl ether and 1673.4 g of N-methyl-2-pyrrolidone as a reaction solvent were charged into a flask equipped with a thermometer, a stirrer and a condenser, and the mixture was dried. In a nitrogen stream, the solution was stirred and dissolved at room temperature (25 ° C.) and pyromellitic dianhydride [trade name: PMDA-M, manufactured by Mitsubishi Gas Chemical Industries, Ltd.] Acid dianhydride 218.12 g (1.0 mol) ) And reacted at 30 ° C. or lower for 5 hours to obtain a polyamic acid solution (solid content concentration: 20 mass%) having a number average molecular weight of 22,700. This was used as a paint.

[Coating film preparation conditions]
The resin solutions obtained in Examples 1 to 3 and Comparative Examples 1 to 3 obtained above were applied to a glass plate and dried to obtain a coating film. The conditions for producing the coating film are shown in Table 1.

（＊）硬化後、市販ガラス板より塗膜を剥離させ各種機械特性を測定した。

(*) After curing, the coating film was peeled off from a commercially available glass plate and various mechanical properties were measured.

[Measurement condition]
The coating film obtained above was subjected to a tensile test under the measurement conditions shown in Table 2, and the breaking elongation (breaking elongation) and tensile strength were measured. The results are summarized in Table 3.

伸び率（引張試験） ：表２に記載の測定条件下にて引張試験を行い、塗膜が破断するまでの伸び率及び引張強度を測定した。

Elongation rate (tensile test): A tensile test was performed under the measurement conditions shown in Table 2, and the elongation rate and tensile strength until the coating film broke were measured.

  From Table 3, the coating film obtained from the heat-resistant polyamide-imide resin using 4,4 ′-(m-phenylenediisopropylidene) imide dicarboxylic acid represented by the formula (I) of Examples 1 to 3, Compared with the coating film obtained from the conventional polyamideimide resin of Comparative Examples 1 and 2, the elongation is remarkably excellent, and the elongation is almost equivalent as compared with the coating film obtained from the polyimide resin of Comparative Example 3. It can be seen that there is a balance between properties of tensile strength and tensile strength.

Claims (8)

(A) a trivalent or higher polycarboxylic acid anhydride having an acid anhydride group and a carboxyl group,
(B) 4,4 ′-(m-phenylenediisopropylidene) imide dicarboxylic acid represented by the formula (I) and

(C) A heat-resistant polyamideimide resin obtained by reacting an aromatic polyisocyanate in a basic polar solvent.   The blending amount of the component (a) and the component (b) is (b) component / (a) component = 0.01 / 0.99 to 0.60 / 0.40 in equivalent ratio. The heat-resistant polyamide-imide resin described.   (C) Isocyanate group and carboxyl of aromatic polyisocyanate, (a) polycarboxylic anhydride and (b) 4,4 '-(m-phenylenediisopropylidene) imide dicarboxylic acid represented by formula (I) The heat-resistant polyamide according to claim 1 or 2, wherein the blending amount with the group is an equivalent ratio of all isocyanate groups / total carboxyl groups = 0.8 to 1.4, and the number average molecular weight is 10,000 to 50,000. Imide resin.   The elongation percentage of a coating film formed of a heat-resistant polyamide-imide resin is 90% or more, and the tensile strength is 100 MPa or more (25 ° C). Resin.   The seamless tubular body shape | molded using the heat resistant polyamide-imide-type resin in any one of Claims 1 thru | or 4.   A coating film formed by applying and heating the heat-resistant polyamide-imide resin according to any one of claims 1 to 4.   A coated plate having a coating film formed by applying and heating the heat-resistant polyamideimide resin according to any one of claims 1 to 4 on a surface.   A heat-resistant paint containing the heat-resistant polyamide-imide resin according to any one of claims 1 to 4 and an organic solvent.