JPH038672B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel metal corrosion-preventing coating. More specifically, the present invention relates to a coating resin composition containing a specific chelate-reactive resin as an active ingredient, and to a lacquer-type anticorrosive paint that has film-forming properties by itself. A coating resin composition that has excellent adhesion and corrosion resistance to not only rust-free steel plates and rust-free steel plates, but also rusted steel plates or poorly prepared steel plates, galvanized steel plates, aluminum, stainless steel, etc. It is about things. Conventional lacquer-type paints have permeability to rust-prone steel plates and the like, and their applications are limited because of their poor adhesion and particularly poor corrosion resistance. The present inventors conducted intensive research to improve the drawbacks of conventional lacquer-type paints, and as a result, a composition containing an epoxy resin-based resin with a high molecular weight and the ability to form chelates with metals as an active ingredient was developed. The present inventors have discovered that this coating has excellent adhesion to metals and particularly excellent corrosion resistance compared to Lutzker type coatings, and has thus arrived at the present invention. That is, the coating resin composition of the present invention has the following general formula () as an essential component. (However, R ₁ ; H or CH ₃ , R ₂ ; -CH ₂ - or

[Manufacturing example 1]

Add 100 parts of bisphenol A diglycidyl ether (epoxy equivalent = 2300), 10 parts of a formalin condensate of catechol (molecular weight = 450), 110 parts of cyclohexanone, and 0.1 part of triethylamine as a catalyst, and heat to 120°C to 130°C with stirring. The reaction continued for 15 hours. The average molecular weight of the reaction product () thus obtained was 12,000. [Production Example 2] 100 parts of bisphenol F diglycidyl ether (epoxy equivalent = 3000) and 8 parts of glycerin protocatechuic acid triester (Mw = 500),
70 parts of ethyl cellosolve and 0.15 parts of dimethylbenzylamine as a catalyst were added, and the reaction was continued at 130°C for 16 hours. The average molecular weight of the reaction product (2) thus obtained was 25,000. [Production Example 3] 100 parts of bisphenol A diglycidyl ether (epoxy equivalent = 3500), 5 parts of glucose m-di-gallic acid ester, 60 parts of methyl isobutyl ketone and 0.2 parts of triethylamine as a catalyst were added and heated at 120°C. The reaction continued for 10 hours. The average molecular weight of the reaction product [] obtained in this way is
It was 13500. [Production Example 4] 100 parts of bisphenol A diglycidyl ether (epoxy equivalent = 2300) and bisphenol A15
110 parts of cyclohexane and 0.1 part of triethylamine as a catalyst and heated at 130°C with stirring for 15 minutes.
The reaction continued for hours. The average molecular weight of the reaction product () thus obtained was 14,000. [Production Example 5] 100 parts of bisphenol F diglycidyl ether (epoxy equivalent = 3000) and bisphenol F6.5
70 parts of ethyl cellosolve and 0.15 parts of dimethybenzylamine as a catalyst were added, and the reaction was continued at 130°C for 10 hours. The average molecular weight of the reaction product () thus obtained was 21,000. [Production Example 6] 100 parts of bisphenol A diglycidyl ether (epoxy equivalent = 3500) and bisphenol A6
1 part, 60 parts of methyl isobutyl ketone and 0.2 part of triethylamine as a catalyst were added, and the reaction was continued at 120°C for 10 hours. The average molecular weight of the reaction product () thus obtained was 14,000. [Production Example 7] Bisphenol F/methyl epichlorohydrin diglycidyl ether (epoxy equivalent = 5500)
100 parts of a formalin condensate of pyrogallol (molecular weight = 390), 120 parts of cyclohexanone, and 2 parts of triethanolamine as a catalyst were added, and the reaction was continued at 120 to 130°C for 10 hours with stirring. The average molecular weight of the reaction product () thus obtained was 14,500. [Production Example 8] Bisphenol F. Methyl epichlorohydrin diglycidyl ether (epoxy equivalent = 3000)
100 parts, 3.5 parts of bisphenol A, 150 parts of cyclohexanone, and 2 parts of triethanolamine as a catalyst.
The reaction was continued at 120 to 130°C for 15 hours with stirring. The average molecular weight of the reaction product (2) thus obtained was 25,000. Examples 1-4, Comparative Examples 1-4 Reaction products obtained in Production Examples 1-8 above []
~ [] Paint test applied to a rusted steel plate (steel plate that has been exposed outdoors for one year to remove loose rust), film thickness 60 to 65μ
After drying at room temperature for one week, the physical properties of the coating films were compared. The results are shown in Table 1. As is clear from Table 1, the Examples of the present invention were significantly superior to the Comparative Examples in both adhesion and corrosion resistance.

[Table] Comparative Example 5 100 parts of bisphenol A diglycidyl ether (epoxy equivalent = 450), 18 parts of formalin condensate of catechol (molecular weight = 450), 50 parts of xylene,
50 parts of methyl isobutyl ketone were mixed, 0.2 parts of triethanolamine was added as a catalyst, the reaction was stirred at 110°C for 8 hours, and the molecular weight was 4500 (epoxy equivalent =
2250) was obtained. This condensate was applied to a rusted steel plate to a film thickness of 60 μm, and after drying at room temperature for one week, the same physical property tests as in Example 1 were conducted. The results were as follows.

【table】

Claims (1)

[Claims] 1. As an essential component, the following general formula (However, R ₁ ; H or CH ₃ , R ₂ ; -CH ₂ - or [Formula] n; 5 to 30) An epoxy resin represented by the following and a polyhydric phenolcarboxylic acid polyhydric alcohol ester having adjacent hydroxyl groups and/or A coating resin composition containing as an active ingredient a reaction product having a molecular weight of 10,000 or more obtained by reacting a polynuclear polyhydric phenol having adjacent hydroxyl groups in a solvent.