JP5176071B2 - Heat resistant resin composition and paint - Google Patents

Description

  The present invention relates to a heat-resistant resin composition suitably used particularly for a sliding member and a paint including various protective coating applications.

  Paints using polyamide-imide resins are widely used as electrical insulation paints, coating materials for various substrates, and binder resins for sliding parts because of their good heat resistance, solvent resistance and chemical resistance. In order to accelerate the curing of the polyamideimide resin, a method using an epoxy resin or a melamine resin has been known. Although the film is cured by using these epoxy resins and melamine resins, there is a drawback that the elongation rate of the mechanical properties and the glass transition temperature of the polyamideimide resin are lowered.

  In general, polyamide-imide resin is excellent in heat resistance, chemical resistance and solvent resistance, so it is especially heat-resistant for forming protective coatings on various substrates as coating film components for enameled wire varnish and various paints. It has been widely used to form coatings.

As a conventional polyamideimide resin, for example, a polyamideimide resin obtained by reaction of 4,4′-diphenylmethane diisocyanate and trimellitic anhydride (see, for example, Patent Document 1 and Patent Document 2) is known.
Japanese Patent Publication No. 44-19274 Japanese Patent Publication No. 45-27611

  The present invention relates to a heat-resistant resin composition and a paint suitable for applications such as improvement in hardness, wear resistance at high temperature and elongation at high temperature, and relaxation of the stress of the coating film to impart slipperiness. The purpose is to provide.

The present invention is a technique for improving the elongation of thermal characteristics and mechanical characteristics by adding a biphenyl type epoxy resin to a polyamideimide resin, compared to the conventional addition of a bisphenol A type epoxy resin.
The present invention relates to the following.

1. A heat resistant resin comprising a polyamideimide resin having a repeating unit represented by the general formula (I) and a structure represented by the general formula (III) and a polyfunctional biphenyl type epoxy resin having a structure represented by the general formula (II) It is a composition, The number average molecular weight of the said polyamideimide resin is 10,000-50,000, The compounding quantity of polyfunctional biphenyl type epoxy resin is 3-30 weight part with respect to 100 weight part of polyamideimide resin. A heat resistant resin composition.

（式中、Ｙ^１は、ジイソシアネート又はジアミンに由来する２価の有機基である。）

(In the formula, Y ¹ is a divalent organic group derived from diisocyanate or diamine.)

（式中、Ｒ^１及びＲ^２は、各々独立に、水素、アルキル基、水酸基、アルコキシ基のいずれかである。）

(In the formula, R ¹ and R ² are each independently hydrogen, an alkyl group, a hydroxyl group, or an alkoxy group.)

（式中、Ｙ²は２価の脂肪族基、またはカルボキシル基末端ゴムのジカルボン酸に由来する２価の有機基である。）

(In the formula, Y ² is a divalent aliphatic group or a divalent organic group derived from the dicarboxylic acid of the carboxyl group-terminated rubber .)

2 . Moles proportion of the general formula (III) to the sum of the moles of the structure of the moles of the general formula of the repeating unit (III) of general formula (I) is 10 to 50 mol%, claim 1 according Heat resistant resin composition.
3 . Item 3. A paint containing the heat resistant resin composition according to Item 1 or 2 .

  According to the present invention, there is provided a heat resistant resin composition and a paint suitable for applications such as improvement of hardness, wear resistance at high temperature and elongation at high temperature, relaxation of coating film stress, and application of slipperiness. It became possible to provide.

First, the polyamide imide (hereinafter referred to as PAI resin) will be described.
Although there is no restriction | limiting in particular in the manufacturing method of PAI resin used for this invention, Usually, it can manufacture by reaction of a tricarboxylic anhydride component, and diisocyanate or diamine. Accordingly, Y ¹ in the general formula (I) is an amidimidation residue of diisocyanate or diamine. In the present invention, the trimellitic anhydride component is preferably trimellitic anhydride in terms of flexibility, storage stability, and cost. Further, the trimellitic anhydride and a tricarboxylic anhydride that reacts with other isocyanate groups or amino groups can be used in combination. As the tricarboxylic acid anhydride, for example, a compound represented by the following formula (IV) can be preferably used.

（ただし、式中、Ｙは−ＣＨ_２−、−ＣＯ−、−ＳＯ_２−又は−Ｏ−を示す。）

(In the formula, Y represents —CH ₂ —, —CO—, —SO ₂ — or —O—).

The diisocyanate or diamine used as an essential component for the production of the PAI resin used in the present invention is represented by the following general formula.
OCN-Y ¹ -NCO
H ₂ N—Y ¹ —NH ₂
In the above general formula, Y ¹ is a divalent organic group such as a divalent aromatic group or a divalent aliphatic group, preferably a divalent aromatic group, and in particular, substituted or unsubstituted diphenylmethanediyl. A polycyclic aromatic group such as a group, a substituted or unsubstituted biphenylylene group, or a condensed cyclic aromatic group such as a substituted or unsubstituted naphthylylene group is preferable. By using diisocyanate or diamine of a diphenylmethane structure derivative, a biphenyl structure derivative, or a naphthalene structure derivative as an essential component, the effect of improving the strength and elastic modulus of dimensional stability, mechanical properties, and the like can be achieved. For example, particularly preferred diisocyanates include 4,4'-diphenylmethane diisocyanate, 2,4-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-diisocyanate biphenyl, naphthalene-1,5-diisocyanate, naphthalene-2, Examples of other diisocyanate components include xylylene diisocyanate, 3,3′-diphenylmethane diisocyanate, and paraphenylene diisocyanate. Particularly preferred diamines include 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, xylylenediamine, phenylenediamine, 2,2'-dimethyl-4, 4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminodiphenylmethane, 3,4-diaminodiphenyl, 2,4-diaminobiphenyl, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene and the like can be mentioned, and other diamines include 2,4-tolylenediamine, 2,6-tolylenediamine, m-xylylenediamine, 3,3′-hydroxyl-4,4 ′. -Diaminobiphenyl and the like.

  Further, as the diisocyanate, those obtained by stabilizing an isocyanate group with a blocking agent may be used. The blocking agent includes alcohol, phenol, oxime, etc., but there is no particular limitation.

  The blending ratio of the diisocyanate or diamine and the acid component having the tricarboxylic acid anhydride component as an essential component is the isocyanate group or the total number of carboxyl groups and acid anhydride groups of the acid component having the tricarboxylic acid anhydride component as an essential component, or The total number ratio of amino groups is preferably 0.6 to 1.4, more preferably 0.7 to 1.3, and more preferably 0.8 to 1.2. It is particularly preferable that If it is less than 0.6 or exceeds 1.4, it tends to be difficult to increase the molecular weight of the resin. In the case of using diamine, it can be obtained by the same production method as in the case of using the diisocyanate shown above, but in addition, diamine and tribasic acid anhydride monochloride as a tricarboxylic acid anhydride component are reacted at low temperature for several hours. Can also be obtained.

（一般式（Ｖ）中、Ｙ¹はジイソシアネート又はジアミンから誘導される２価の有機基であり、Ｙ²は２価の脂肪族基、またはカルボキシル基末端ゴムのジカルボン酸に由来する２価の有機基である。）
ただし、上記一般式（Ｖ）においては、Ｙ¹はジイソシアネート又はジアミンのジアミド化残基である。 Polyamideimide resin used in the present invention further have the structure of general formula (III) above. Y ² in the general formula (III) is a diamide of residues of dicarboxylic acids, a divalent aliphatic group or a divalent organic group derived from a carboxyl group-terminated rubber. In order to introduce the repeating unit of the general formula (III), a dicarboxylic acid component is further used in addition to the diisocyanate or diamine and the tricarboxylic anhydride component. The structure of the dicarboxylic acid component, fat aliphatic dicarboxylic acids (succinic acid, glutaric acid, adipic acid, azelaic acid, suberic acid, sebacic acid, decanoic acid, dodecanedioic acid, and dimer acid), also acrylic modified A modified carboxylic acid such as a terminal carboxylic acid, for example, a carboxyl group terminal acrylonitrile-butadiene rubber can be used in combination. When the dicarboxylic acid (the former) is used in combination as the acid component for the introduction of the structure of the general formula (III), the ratio of the diisocyanate component or the diamine component (the latter) to the former is 10-50 / 100 (moles). Ratio), and the former / the latter is most preferably 10 to 30/100 (molar ratio). In this case, examples of the repeating unit having the structure of the general formula (III) include those represented by the following general formula (V).

(In general formula (V), Y ¹ is a divalent organic group derived from diisocyanate or diamine, and Y ² is a divalent aliphatic group or a divalent acid derived from a dicarboxylic acid of a carboxyl group-terminated rubber . Organic group.)
However, in the general formula (V), Y ¹ is a diamidated residue of diisocyanate or diamine.

  The ratio of the number of moles of the structure of the general formula (III) to the total number of moles of the repeating unit of the general formula (I) and the number of moles of the structure of the general formula (III) is preferably 0 to 50 mol%. When introducing the structure of the general formula (III), the content is preferably 10 to 50 mol%, more preferably 10 to 30 mol%. The ratio of the number of moles of the structure of the general formula (V) to the sum of the number of moles of the repeating unit of the general formula (I) and the number of moles of the repeating unit represented by the general formula (V) is the same.

  The polyamide-imide resin used in the present invention has a number average molecular weight of 10,000 to 50,000, preferably 17,000 to 30,000. When the number average molecular weight is less than 10,000, the film formability tends to deteriorate and the mechanical properties tend to deteriorate. When it exceeds 50,000, the moldability as a film and the thickness accuracy tend to be inferior. Furthermore, the storage stability tends to be significantly impaired.

The number average molecular weight of PAI resin is sampled during resin synthesis, by gel permeation chromatography (GPC), was measured using a calibration curve of standard poly scan styrene, a synthetic until the number average molecular weight of interest Managed by continuing.

  As the polyfunctional biphenyl type epoxy resin having the structure represented by the general formula (II) in the present invention, a tetramethyl biphenol type epoxy resin, a 4,4′-biphenol type epoxy resin, or the like can be used. These epoxy resins are blended in an amount of 3 to 30 parts by weight, preferably 5 to 20 parts by weight, based on 100 parts by weight of the polyamideimide resin. Here, polyfunctional means having a monovalent or higher-valent epoxy side group. By adding the epoxy resin having the structure of (II), the elongation of the resin during heating is improved.

（式中、Ｒ¹、Ｒ²は上記と同じ意味を有し、ｎは０以上の整数、好ましくは０〜３の整数である。）
Ｒ¹、Ｒ²で示されるアルキル基及びアルコキシ基としては、例えば、炭素数１〜１０のアルキル基及びアルコキシ基が挙げられる。 Examples of the polyfunctional biphenyl type epoxy resin having a structure represented by the general formula (II) include those represented by the following general formula (VI).

(In the formula, R ¹ and R ² have the same meaning as above, and n is an integer of 0 or more, preferably an integer of 0 to ^3. )
Examples of the alkyl group and alkoxy group represented by R ¹ and R ² include an alkyl group having 1 to 10 carbon atoms and an alkoxy group.

  The paint of the present invention contains the above heat-resistant resin composition of the present invention, and further contains a solvent, a lubricant, a pigment, an antifoaming agent, a leveling agent, and the like as necessary. Also good.

  The coating material of the present invention preferably has a viscosity (viscosity at 25 ° C .; the same applies to the examples) of 1 to 30 Pa · s, more preferably 4 to 10 Pa · s, and a non-volatile content of 15 to 45. It is preferable that it is weight%, and it is more preferable that it is 25-35 weight%.

  A normal polyamideimide resin composition or paint is preferably heat-treated for drying and curing and heated at least at 150 ° C. for 10 minutes. This is because the solvent remains when cured at a low temperature, and the coating film properties that protect the substrate may be inferior. Moreover, in the case of curing at less than 150 ° C., the coating film is not sufficiently cured and may be dissolved or swollen in a polar solvent. The heat resistant resin composition or paint of the present invention can be dried and cured at 150 to 380 ° C. for 10 to 60 minutes. When the heating time is less than 10 minutes, the residual solvent remains on the coating film, and the characteristics of the coating film applied to the substrate may be inferior. When the heating time exceeds 60 minutes, it is solid as a paint by applying heat for a long time. When a lubricant or the like is added, a side reaction may occur and the properties of the coating film may be deteriorated.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
Synthesis example 1
Trimellitic anhydride 153.7 g (0.8 mol) and sebacic acid 40.4 g (0.2 mol) as acid components in a 2 liter four-necked flask equipped with a stirrer, condenser, nitrogen inlet tube and thermometer As an isocyanate component, 250.3 g (1.0 mol) of 4,4′-diphenylmethane diisocyanate and 945.5 g of N-methyl-2-pyrrolidone were charged, heated to 130 ° C., reacted for about 7 hours, and number averaged. A PAI resin solution having a molecular weight of 27,000 was obtained. This PAI resin solution was diluted with N-methyl-2-pyrrolidone to obtain a PAI resin solution having a viscosity of 7.3 Pa · s and a nonvolatile content of 23.5% by weight. This PAI resin solution is designated as Resin 1.

Synthesis example 2
Trimellitic anhydride 134.5 g (0.7 mol) and sebacic acid 60.3 g (0.3 mol) as acid components in a 2 liter four-necked flask equipped with a stirrer, cooling tube, nitrogen inlet tube and thermometer And 3,3'-dimethyl-4,4'-diisocyanate biphenyl 105.7 g (0.40 mol), 4,4'-diphenylmethane diisocyanate 75.1 g (0.3 mol), naphthalene-1,5 -63.1 g (0.30 mol) of diisocyanate and 785.2 g of N-methyl-2-pyrrolidone were charged, heated to 130 ° C., and reacted for about 6 hours to obtain PAI having a number average molecular weight of 31,000. This PAI resin solution was diluted with N-methyl-2-pyrrolidone to obtain a PAI resin solution having a viscosity of 6.9 Pa · s and a non-volatile content of 23.1% by weight. This PAI resin solution is designated as Resin 2.

Synthesis example 3
Trimellitic anhydride 188.3 g (0.98 mol), CTBN 1300 × 9; 70 g (0.02 mol) as an acid component in a 2 liter four-necked flask equipped with a stirrer, condenser, nitrogen inlet tube and thermometer And 4,4′-diphenylmethane diisocyanate 250.3 g (1.0 mol) and N-methyl-2-pyrrolidone 983.7 g as an isocyanate component, heated to 140 ° C. and reacted for about 4 hours to give a number average molecular weight A 27,000 PAI resin solution was obtained. This PAI resin solution was diluted with N-methyl-2-pyrrolidone to obtain a PAI resin solution having a viscosity of 8.0 Pa · s and a nonvolatile content of 23.9% by weight. This PAI resin solution is designated as Resin 3.

Synthesis example 4
In a 2 liter four-necked flask equipped with a stirrer, a cooling tube, a nitrogen inlet tube and a thermometer, 192.0 g (1.0 mol) of trimellitic anhydride as an acid component and naphthalene-1,5-diisocyanate as an isocyanate component 210.2 g (1.0 mol) and N-methyl-2-pyrrolidone 938.5 g were charged, heated to 130 ° C. and reacted for 7 hours to obtain a PAI resin solution having a number average molecular weight of 21,000. This PAI resin solution was diluted with N-methyl-2-pyrrolidone to obtain a PAI resin solution having a viscosity of 4.6 Pa · s and a nonvolatile content of 23.0% by weight. This PAI resin solution is referred to as Resin 4.

In the examples, varnishes of Synthesis Examples 1 to 3 were mixed with 50% by weight / 50% by weight of tetramethylbiphenol type epoxy resin and 4,4′-biphenol type epoxy resin (Japan Epoxy Resin Co., Ltd., trade name: Epicoat YL6121H). Was added at each weight% (based on solid content) to obtain a PAI resin composition. In Reference Example 1, a mixture of tetramethylbiphenol type epoxy resin and 4,4′-biphenol type epoxy resin 50% by weight / 50% by weight (made by Japan Epoxy Resin Co., Ltd., trade name: Epicoat YL6121H) is applied to the varnish of Synthesis Example 4. It added by each weight% (solid content basis) and was set as the PAI resin composition. As a comparative example, bisphenol A type epoxy resin (manufactured by Toto Kasei Co., Ltd., trade name: YD-128, epoxy equivalent: 184 to 194) is added to each varnish of Synthesis Examples 1 to 4 in weight percent (solid content basis), A PAI resin composition was obtained.

Scratch strength (pencil method)
The PAI resin composition is applied on an aluminum plate A1050P (dimensions: 1 mm × 50 mm × 150 mm), and then cured by heating at 200 ° C. for 60 minutes to form a coating film having a thickness of about 20 μm. A scratch strength test with a pencil was performed using the obtained coating film plate, and the pencil hardness at which the coating film was not damaged was described.

Adhesion test (cross cut test)
The PAI resin composition is applied on an aluminum plate A1050P (dimensions: 1 mm × 50 mm × 150 mm), and then cured by heating at 200 ° C. for 60 minutes to form a coating film having a thickness of about 20 μm. 100 1-mm grids (10 × 10) were made with a cutter, and the peel test was performed 5 times with a cellophane tape, and the ratio of cross-cut grids (cross cut residual rate:%) was examined.

Mechanical properties (measurement of mechanical strength, elastic modulus and elongation)
The PAI resin composition is heated and cured at 180 ° C. for 30 minutes to form a coating film having a thickness of about 20 μm, a width of 10 mm, and a length of 60 mm. The obtained coating film was subjected to a tensile test using a tensile tester under conditions of a length between chucks of 20 mm and a tensile speed of 5 mm / min to obtain mechanical characteristics. As for the result, the tensile test result in 25 degreeC and 180 degreeC was described.
The results are shown in Table 1.

１）測定温度
２）２５０℃硬化

1) Measurement temperature 2) 250 ° C curing

  From the results shown in Table 1, the PAI resin composition obtained in the examples of the present invention has improved pencil hardness (hardness of the coating film) by using a polyfunctional biphenyl type epoxy resin, It can be seen that the mechanical properties have no change in strength and elastic modulus, but the elongation at 180 ° C. is high. Moreover, the glass transition temperature is rising. Since the heat-resistant resin composition of the present invention is improved in hardness and used in the field of wear resistance at high temperatures and the elongation rate at high temperatures is improved, the stress of the coating film is reduced. Suitable for applications and the like.

Claims (3)

A heat resistant resin comprising a polyamideimide resin having a repeating unit represented by the general formula (I) and a structure represented by the general formula (III) and a polyfunctional biphenyl type epoxy resin having a structure represented by the general formula (II) It is a composition, The number average molecular weight of the said polyamideimide resin is 10,000-50,000, The compounding quantity of polyfunctional biphenyl type epoxy resin is 3-30 weight part with respect to 100 weight part of polyamideimide resin. A heat resistant resin composition.

(In the formula, Y ¹ is a divalent organic group derived from diisocyanate or diamine.)

(In the formula, R ¹ and R ² are any one of hydrogen, an alkyl group, a hydroxyl group, and an alkoxy group.)

(In the formula, Y ² is a divalent aliphatic group or a divalent organic group derived from the dicarboxylic acid of the carboxyl group-terminated rubber.) The ratio of the number of moles of the structure of the general formula (III) to the total number of moles of the repeating unit of the general formula (I) and the number of moles of the structure of the general formula (III) is 10 to 50 mol%. 1. The heat resistant resin composition according to 1 . The coating material containing the heat resistant resin composition of Claim 1 or Claim 2 .