JP2012241052A - Heat-resistant resin composition and aluminum base material using this - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide-imide heat-resistant resin composition forming a coating film which is excellent in heat resistance, chemical resistance and solvent resistance, and has excellent adhesive properties without performing a surface treatment for improving adhesive properties to an aluminum base material, and an aluminum base material using this composition.SOLUTION: The heat-resistant resin composition includes: 100 mass pts. polyamide-imide resin with a number average molecular weight of 10,000-50,000; 0.1-10 mass pts. polybutadiene; and 0.01-1 mass pt. triazine thiol derivative. It is preferable that an epoxy resin is furthermore included. The aluminum base material prepared by forming the heat-resistant resin composition on the aluminum base material, is provided.

Description

  The present invention relates to a heat resistant resin composition for forming a coating film having excellent adhesion to an aluminum substrate, and more specifically, a heat resistant resin composition suitable for an insulating film, a protective coat and the like of an aluminum substrate and the composition. The present invention relates to an aluminum substrate using

Polyamideimide resins have excellent heat resistance, chemical resistance, and solvent resistance, and are therefore widely used as varnishes for enameled wires, heat resistant paints, and the like as coating agents for various substrates. On the other hand, an example in which an aluminum base material that is lightweight and excellent in heat dissipation is used for automobile parts, food-related appliances, and the like is increasing. When heat-resistant paints based on polyamide-imide resin are applied to aluminum substrates, there is difficulty in adhesion between the coating film and the aluminum substrate, and in general the aluminum substrate is physically (polished, etc.) and chemicals to improve adhesion. Surface treatment is performed by a method (etching with acid, alkali, etc.) to form unevenness on the surface of the base material, or a phosphate treatment or a chromate treatment is applied to form a chemical conversion film and then coated.
In addition, the surface treatment of the triazine thiol derivative by electrolytic polymerization (see Patent Document 1), or the polycarbonate resin or ABS resin mixed with an epoxy-based, polystyrene-based rubber component or triazine thiol and injection-molded to form a composite of the resin and aluminum (See Patent Document 2).
These have problems such as complication of the painting process, cost increase, and pollution measures related to the treatment of waste materials, and there is an increasing need to omit the surface treatment of the aluminum base material.

JP 2005-109363 A Japanese Patent Laid-Open No. 08-025409

  The present invention is a polyamide-imide that is excellent in heat resistance, chemical resistance, and solvent resistance, and forms a coating film having excellent adhesion without performing a surface treatment for improving adhesion to an aluminum substrate. The present invention provides a heat resistant resin composition and an aluminum substrate using the composition.

The present invention includes 100 parts by mass of a polyamideimide resin having a number average molecular weight of 10,000 to 50,000, 0.1 to 10 parts by mass of polybutadiene, and 0.01 to 1 part by mass of a triazine thiol derivative. The present invention relates to a resin composition.
Moreover, it is preferable that the heat resistant resin composition of the present invention further contains an epoxy resin.
Furthermore, this invention relates to the aluminum base material in which the said heat resistant resin composition was formed.

  According to the heat resistant resin composition of the present invention, a coating film having excellent heat resistance, chemical resistance and solvent resistance and having excellent adhesion without performing surface treatment on an aluminum substrate can be prepared. It is useful for heat resistant paint applications.

The present invention includes 100 parts by mass of a polyamideimide resin having a number average molecular weight of 10,000 to 50,000, 0.1 to 10 parts by mass of polybutadiene, and 0.01 to 1 part by mass of a triazine thiol derivative. It is a resin composition. Below, each component used by this invention is demonstrated.
The polyamideimide resin used in the present invention has a structure represented by the general formula (I).

（一般式（Ｉ）中、Ｒ_３は、ポリイミド樹脂の製造に用いられるジアミンの残基である。なお、残基とは、原料成分から結合に供された官能基を除いた部分の構造をいう。ｎは、正の整数を示す。）

(In general formula (I), R ₃ is a residue of a diamine used in the production of a polyimide resin. The residue is the structure of a portion excluding the functional group provided for bonding from the raw material component. (N represents a positive integer.)

  The production method of the polyamideimide resin used in the present invention is not particularly limited, but typical production methods include (1) a method of reacting diisocyanate and tribasic acid anhydride, and (2) diamine and tribasic acid. There are a method of reacting an anhydride and a method of reacting (3) a diamine and a tribasic acid anhydride chloride.

Typical materials include diisocyanates, and aromatic diisocyanates include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, xylylene diisocyanate, 3,3'-diphenylmethane diisocyanate, 3, 3'-dimethyl-4,4'-diisocyanatobiphenyl, naphthalene-1,5-diisocyanate, paraphenylene diisocyanate, and the like. Aliphatic diisocyanates such as 1,6-hexamethylene diisocyanate and isophorone diisocyanate, alicyclic rings Diisocyanates and their trimers, isocyanurate ring-containing polyisocyanates obtained by the above trimerization reaction of aromatic diisocyanates, polyphenylmethyl polyisocyanates Sulfonates, for example, a condensate of aniline and full ol formaldehyde may be used in combination such as those Fuosugen of.
Examples of the diamine include 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfone, 3,3′-diaminodiphenyl sulfone, xylylenediamine, phenylenediamine, and the like.
Examples of tribasic acid anhydrides include trivalent or higher polycarboxylic acids having acid anhydride groups or derivatives thereof, and trivalent or higher polycarboxylic acids having acid anhydride groups that react with isocyanate groups or amino groups or the like. There is no particular limitation as long as it is a derivative, but for example, it can be represented by general formula (II) or general formula (III)

（一般式（ＩＩ）、（III）中、Ｒは水素、アルキル基、フェニル基又はハロゲンを示し、Ｙは−ＣＨ₂−、−ＣＯ−、−ＳＯ₂−又は−Ｏ−を示す。）
で表される化合物を使用することができる。耐熱性、コスト面等を考慮すれば、トリメリット酸無水物が特に好ましい。

(In general formulas (II) and (III), R represents hydrogen, an alkyl group, a phenyl group or halogen, and Y represents —CH ₂ —, —CO—, —SO ₂ — or —O—).
The compound represented by these can be used. In view of heat resistance, cost, etc., trimellitic anhydride is particularly preferable.

Trimellitic anhydride as tribasic acid anhydride, trimellitic acid chloride as tribasic acid chloride, and trimesic acid, tris (2-carboxyethyl) isocyanurate as tribasic acid .
Examples of materials that can be used in combination include terephthalic acid, isophthalic acid, adipic acid, succinic acid, sebacic acid, and dodecanedicarboxylic acid as dicarboxylic acids, and pyromellitic dianhydride and benzophenone as tetracarboxylic dianhydrides. Tetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, ethylene glycol bistri Melitte dianhydride, 2,2'-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2 ', 3,3'-diphenyltetracarboxylic dianhydride, perylene-3, Aromatic four such as 4,9,10-tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride Basic acids, 1,2,3,4-butanetetracarboxylic acid, cyclopentanetetracarboxylic acid, ethylenetetracarboxylic acid, bicyclo- [2,2,2] -oct- (7) -en-2: 3,5 : Tetrabasic acid dianhydrides such as aliphatic and alicyclic tetrabasic acids such as 6-tetracarboxylic acid.

The above-mentioned synthesis conditions are various and cannot be generally specified. For example, the most typical method of reacting diisocyanate and tribasic acid anhydride is exemplified in JP-A-4-39323.
The number average molecular weight of the polyamideimide resin is in the range of 10,000 to 50,000. When the number average molecular weight is less than 10,000, the film-forming property is lowered. When the number average molecular weight is more than 50,000, the viscosity of the finally obtained heat-resistant resin composition is increased and the workability at the time of coating is inferior. The number average molecular weight of the polyamideimide resin is measured by sampling the resin at the time of resin synthesis and using an analytical instrument such as a gel permeation chromatograph (GPC) and continuing the synthesis until the desired number average molecular weight is reached. It is managed in the above range.

As the polybutadiene used in the present invention, natural rubber or the like can be used, and the reactivity increases when 0.01% by mass of stearic acid is added.
Polybutadiene includes compounds having “1,4-repeat units” or “1,2-repeat units”. Here, in the polybutadiene, “1,4-repeating unit” is a repeating unit represented by the following chemical formula (1t) or (1c), and “1,2-repeating unit” is the following chemical formula. It is a repeating unit represented by (1d).

また、これらのポリブタジエンは、両末端に水酸基を有するポリブタジエンジオール、両末端にカルボキシル基を有するポリブタジエンジカルボン酸等を用いることもできる。ポリアミドイミド樹脂との相溶性の観点からは、ポリブタジエンジオール又はポリブタジエンジカルボン酸が好ましい。
１，２−繰り返し単位を主に有するポリブタジエンジオールとしては、下記一般式（１）で表される化合物が例示され、具体的には、Ｇ−１０００、Ｇ−２０００，Ｇ−３０００（日本曹達株式会社製、商品名）が挙げられる。また、１，２−繰り返し単位を主に有するポリブタジエンジカルボン酸としては、例えば、Ｃ−１０００（日本曹達株式会社製、商品名）が挙げられる。
１，４−繰り返し単位を主に有するポリブタジエンジオールとしては、下記一般式（２）で表される化合物が例示され、具体的には、Ｐｏｌｙ ｂｄ Ｒ−４５ＨＴ、Ｐｏｌｙ ｂｄ Ｒ−１５ＨＴ（出光興産株式会社製、商品名）が挙げられる（１，４−繰り返し単位が全体の約８０％）。
また、下記一般式（３）で表されるブタジエンとアクリロニトリルを共重合して得られるブタジエン−アクリロニトリル共重合体をポリブタジエン成分として用いても良い。

In addition, these polybutadienes may be polybutadiene diol having hydroxyl groups at both ends, polybutadiene dicarboxylic acid having carboxyl groups at both ends, or the like. From the viewpoint of compatibility with the polyamideimide resin, polybutadiene diol or polybutadiene dicarboxylic acid is preferable.
Examples of the polybutadiene diol mainly having 1,2-repeating units include compounds represented by the following general formula (1), specifically G-1000, G-2000, G-3000 (Nippon Soda Co., Ltd.) Company name, product name). Moreover, as polybutadiene dicarboxylic acid which has a 1, 2- repeating unit mainly, C-1000 (Nippon Soda Co., Ltd. make, brand name) is mentioned, for example.
Examples of the polybutadiene diol mainly having 1,4-repeating units include compounds represented by the following general formula (2). Specifically, Poly bd R-45HT, Poly bd R-15HT (Idemitsu Kosan Co., Ltd.) Company name, product name) (1,4-repeat unit is about 80% of the total).
Further, a butadiene-acrylonitrile copolymer obtained by copolymerizing butadiene and acrylonitrile represented by the following general formula (3) may be used as a polybutadiene component.

［一般式（１）中、ｎ１は１〜６０の整数を示す。］

[In general formula (1), n1 shows the integer of 1-60. ]

［一般式（２）中、ｎ２は１〜３０の整数を示し、ｘ及びｙはそれぞれ独立に１以上の整数を示す。ｘとｙの比（ｘ／ｙ）は、１／９９〜２５／７５である。］

[In General Formula (2), n2 represents an integer of 1 to 30, and x and y each independently represents an integer of 1 or more. The ratio of x to y (x / y) is 1/99 to 25/75. ]

一般式（３）中、ｍは５〜５０の整数を示し、ａ及びｂはそれぞれ独立に１以上の整数を示す。ａとｂの比（ａ／ｂ）は、９５／５〜５０／５０であることが好ましい。

In general formula (3), m represents an integer of 5 to 50, and a and b each independently represent an integer of 1 or more. The ratio of a to b (a / b) is preferably 95/5 to 50/50.

The number average molecular weight of the polybutadiene used in the present invention is preferably 1,000 to 5,000, more preferably 1,000 to 3,000.
The polybutadiene used in the present invention is more preferably a polybutadiene mainly having 1,4-repeat units from the viewpoint of excellent adhesion to an aluminum substrate.

Examples of the triazine thiol derivative used in the present invention include 2,4,6-trimercapto-s-triazine, 2-dibutylamino-4,6-dimercapto-s-triazine, 2-anilino-4,6-dimercapto- Examples thereof include s-triazine. Commercially available products of these compounds include “DISNET F” (trade name: 2,4,6-trimercapto-s-triazine) and “DISNET DB” (trade name: 2-dibutylamino) manufactured by Sankyo Kasei Co., Ltd. -4,6-dimercapto-s-triazine), "disnet AF" (trade name: 2-anilino-4,6-dimercapto-s-triazine) and the like.
The content of the triazine thiol derivative is in the range of 0.01 to 1 part by mass with respect to 100 parts by mass of the polyamideimide resin, and preferably 0.05 to 0.08 part by mass from the viewpoint of adhesiveness. If it is less than 0.01 part by mass, the curability and the polyamide-imide resin and the polybutadiene are easily separated, and if it exceeds 1 part by mass, the viscosity stability of the solution is lowered.

The usage-amount of polybutadiene shall be the range of 0.1-10 mass parts with respect to 100 mass parts of polyamide-imide resins, Preferably it shall be 1-5 mass parts. If the amount of polybutadiene used is less than 0.1 parts by mass, flexibility cannot be obtained, the adhesion of the coating film and the followability to the substrate are lowered, and if it exceeds 10 parts by mass, the heat resistance is inferior.
Although there is no restriction | limiting in particular about the addition method to the polyamidoimide resin of polybutadiene, For example, there exist the method of adding polybutadiene to the solution of a polyamidoimide resin, and the method of adding before a synthesis | combination.
The heat-resistant resin composition according to the present invention includes polar solvents such as N-methyl-2-pyrrolidone and N, N′-dimethylformamide, aromatic hydrocarbons such as xylene and toluene, methyl ethyl ketone, methyl isobutyl ketone, and γ-butyrolactone. It is diluted with a solvent such as ketones and the like and adjusted to an appropriate viscosity. The heat resistant resin composition according to the present invention is applied and cured on an aluminum-based substrate.

In this invention, it can be set as the heat resistant resin composition which contains an epoxy resin further in said heat resistant resin composition.
The epoxy resin is not particularly limited as long as it is an epoxy resin having two or more epoxy groups in one curable molecule, and an epoxy resin generally used in a resin composition for electronic parts can be used. For example, an epoxy resin having a naphthalene skeleton, a glycidyl ether type epoxy resin or an orthocresol novolak type epoxy resin obtained by reaction of bisphenol A, bisphenol F, bisphenol AD, bisphenol S, naphthalene diol, hydrogenated bisphenol A, etc. with epichlorohydrin Novolak type epoxy resin obtained by epoxidizing novolak resin obtained by condensation or cocondensation of phenols and aldehydes such as glycidyl ester type epoxy obtained by reaction of polybasic acids such as phthalic acid and dimer acid and epichlorohydrin Resin, diaminodiphenylmethane, isocyanuric acid and other polyamines and epichlorohydrin obtained by the reaction of epichlorohydrin, olefinic bonds such as peracetic acid In obtained by oxidizing the linear aliphatic epoxy resins, and the like alicyclic epoxy resins may be used in combination of two or more even with these alone.

When using an epoxy resin, what is generally used as a hardening | curing agent of an epoxy resin can be used as the hardening | curing agent.
For example, phenols such as phenol, cresol, resorcin, catechol, bisphenol A, bisphenol F, phenylphenol, thiodiphenol, aminophenol, α-naphthol, β-naphthol, and dihydroxynaphthalene, and aldehydes such as formaldehyde, benzaldehyde, and salicylaldehyde Novolak-type phenolic resin obtained by condensation or cocondensation of a group-containing compound with an acidic catalyst, phenol / aralkyl resin, naphthol / aralkyl resin, etc. synthesized from phenol and dimethoxyparaxylene or bis (methoxymethyl) biphenyl Aralkyl-type phenolic resin, a phenolic aralkyl structure in which a phenol novolac structure and a phenol-aralkyl structure are randomly, block, or alternately repeated Examples include alkyl resins, paraxylylene and / or metaxylylene modified phenol resins, melamine modified phenol resins, terpene modified phenol resins, dicyclopentadiene modified phenol resins, cyclopentadiene modified phenol resins, polycyclic aromatic ring modified phenol resins, etc. Or may be used in combination of two or more.

  When using an epoxy resin, you may contain a hardening accelerator. The curing accelerator is not particularly limited as it is generally used for epoxy resins. For example, 1,8-diazabicyclo [5.4.0] undecene-7,1,5-diazabicyclo [4.3.0] nonene-5,5,6-dibutylamino-1,8-diazabicyclo [5.4 0.0] cycloamidine compounds such as undecene-7, and the like may be used alone or in combination of two or more.

  The ratio of the epoxy resin and the polyamide-imide resin is 5/95 to 90/10 (parts by mass), preferably 10/90 to 90/10 (parts by mass), and more preferably 10/90 to 85/15. (Part by mass). If the ratio of the epoxy resin and the polyamideimide resin is outside this range, the heat resistance tends to be inferior.

  In addition, the heat-resistant resin composition of the present invention includes dyes, pigments, plasticizers, and fillers such as titanium dioxide, silica, alumina, talc, calcium carbonate, and barium sulfate, antifoaming agents, and stability as necessary. An agent, an adhesion-imparting agent, a leveling agent, a coupling agent (such as silane, titanate, aluminum, or zirconium), an antioxidant, a fragrance, or an imaging agent can be contained. These components are each preferably contained in an amount of about 0.01 to 20% by mass as the content in the heat resistant resin composition. Moreover, said component can be used individually by 1 type or in combination of 2 or more types.

  Furthermore, the heat-resistant resin composition of the present invention can be prepared by using a solvent such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylformamide, propylene glycol monomethyl ether, or the like as necessary. It can melt | dissolve in a mixed solvent and can apply | coat as a solution of solid content about 30-70 mass%.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.
Example 1
While stirring 257.5 g (1.03 mol) of 4,4'-diphenylmethane diisocyanate, 192.0 g (1.00 mol) of trimellitic anhydride and 660 g of N-methyl-2-pyrrolidone, the mixture was stirred. The temperature was raised to 130 ° C. in about 3 hours, and the temperature was kept at this temperature for 6 hours to obtain a polyamideimide resin solution having a number average molecular weight of 20,000. Next, the polyamidoimide resin solution 100 parts by mass (resin content concentration 30% by mass), polybutadienediol (Poly bd, manufactured by Idemitsu Kosan Co., Ltd.) 18 g parts by mass, 2,4,6-trimercapto-s-triazine 0.02 g (0.05 parts by mass) (manufactured by Sankyo Kasei Co., Ltd.) was blended to obtain a heat resistant resin composition.

(Example 2)
257.5 g (1.03 mol) of 4,4′-diphenylmethane diisocyanate, 192.1 g (1.00 mol) of trimellitic anhydride, 904 g of N-methyl-2-pyrrolidone and polybutadiene diol (Poly bd, Idemitsu Kosan Co., Ltd.) 40.0 g parts by mass) was charged into a 2 liter flask, the temperature was raised to 130 ° C. in about 2 hours with stirring, and the mixture was kept at this temperature for 6 hours to obtain a polyamideimide resin solution. The number average molecular weight of the obtained polyamideimide resin was 23,000. Next, 0.02 g (0.05 mass) of 2,4,6-trimercapto-s-triazine (manufactured by Sankyo Kasei Co., Ltd.) was added to 100 mass parts (resin concentration 25 mass%) of the obtained polyamideimide resin solution. Part) to obtain a heat resistant resin composition.

(Comparative Example 1)
While stirring 257.5 g (1.03 mol) of 4,4'-diphenylmethane diisocyanate, 192.0 g (1.00 mol) of trimellitic anhydride and 660 g of N-methyl-2-pyrrolidone, the mixture was stirred. The temperature was raised to 130 ° C. in about 3 hours, and the temperature was kept at this temperature for 4 hours to obtain a polyamideimide resin solution (polyamideimide resin composition). The number average molecular weight of the obtained polyamideimide resin was 18,000.

[Test example]
After applying the heat-resistant resin composition or the polyamide-imide resin composition obtained in Examples 1 and 2 and Comparative Example 1 to a substrate (aluminum plate JIS H 4000, thickness 1 mm, unpolished), baking was performed at 270 ° C. for 30 minutes. Thus, a coating plate having a film thickness of about 13 μm was prepared, and the initial adhesion was measured.
(1) Adhesion was measured according to the old JIS K 5400 (%, crosscut residual rate).
(2) The followability of the coating film was measured by bending the aluminum plate and peeling or cracking.
(3) Mechanical properties (measurement of tensile breaking strength and breaking elongation) A heat-resistant resin composition or a polyamide-imide resin composition is cured by heating at 200 ° C. for 30 minutes, and has a film thickness of about 20 μm, a width of 10 mm, and a length. A 60 mm coating film was formed. 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.
(4) Thermal characteristic coating film curing conditions: Cured for 30 minutes on a hot plate at 80 ° C., and cured for 30 minutes at 240 ° C. in a hot air box dryer to obtain a coating film having a film thickness of about 35 μm. A 5 mass% mass reduction temperature was raised at 10 ° C./min in an air stream using a TG-DTA measuring device (SII Nano Technology Co., Ltd.), and the temperature at which the mass was reduced by 5% from the beginning was measured. The measurement results are summarized in Table 1.

  From Table 1, the coating film obtained from the heat-resistant resin composition obtained in Examples 1 and 2 is remarkably superior in flexibility as compared with the coating film obtained from the polyamideimide resin solution of Comparative Example 1. Indicated.

Claims (3)

  A heat-resistant resin composition comprising 0.1 to 10 parts by mass of polybutadiene and 0.01 to 1 part by mass of a triazine thiol derivative in 100 parts by mass of a polyamideimide resin having a number average molecular weight of 10,000 to 50,000.   The heat resistant resin composition according to claim 1, further comprising an epoxy resin.   The aluminum base material which formed the heat resistant resin composition of Claim 1 or 2 on the aluminum base material.