JPH029064B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a coating resin composition. More specifically, the present invention relates to a corrosion-resistant coating composition containing a specific chelate-reactive polyol resin, an isocyanate curing agent, and a bituminous material or a substitute thereof. In particular, the present invention provides a coating material that has excellent adhesion and corrosion resistance to not only rust-free steel plates and derusted steel plates, but also rusted steel plates or poorly prepared steel plates, aluminum, galvanized steel plates, stainless steel, etc. The present invention relates to a composition. Conventional polyol resin paints are used as metal protective paints in a wide range of fields because of their excellent corrosion resistance. However, in order to maintain its excellent corrosion resistance, it is necessary to carefully remove rust from the surface of the steel plate and thoroughly prepare the surface. If the coating is applied with insufficient surface treatment, poor adhesion will occur and the anticorrosion performance will be significantly reduced. The purpose of the present invention is to provide not only rust-free steel plates, but also coating resin compositions that simplify the surface treatment of steel plates, or coating resin compositions that have excellent adhesion and corrosion resistance even when directly applied to rusted steel plates. It's about providing things. The coating resin composition of the present invention has as essential components:
phosphorous acid having at least one P-OH bond;
A polyol resin (A-3) obtained by reacting a precondensate obtained from its ester or salt (A-2) and an epoxy resin (A-1) with a compound (A-3) containing an amino group reactive with an epoxy group. A) and a compound (B) containing more than one isocyanate group or a group that converts to isocyanate under curing conditions.
and bituminous substances and/or their substitutes (C). The precondensate, which is an essential component of the composition of the present invention, is a mixture of an epoxy resin (A-1) and a phosphoric acid, a hydroxyl group-containing phosphate ester, or a salt thereof (A-2). It can be obtained by heat treatment in the presence or absence of a solvent in such a proportion that it remains. The heating temperature is not particularly limited, but it is preferably 50 to 130°C in order to prevent decomposition of the epoxy resin and to complete the reaction in an appropriate time. The epoxy resin (A-1) used here has the formula (Z is H, CH ₃ , C ₂ H ₅ group) Various types can be used, such as those having more than one substituted or unsubstituted glycidyl ether group in the molecule, and the epoxy equivalent is particularly There is no limit, but preferably epoxy equivalent is 200 to 1000
Something of a certain degree is good. At least one P—OH used in the present invention
Examples of the phosphorus acid having a bond include orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, phosphorous acid, polyphosphoric acid, phosphonic acid, and phosphinic acid, with orthophosphoric acid being particularly preferred. Examples of phosphorus acid esters include the above-mentioned phosphorus acid esters, preferably alkyl esters having up to about 8 carbon atoms (those having one or more hydroxyl groups) and hydroxyalkyl esters, such as:
Examples include those having groups such as ethyl, n-butyl, 2-ethylhexyl, hydroxyethyl, hydroxybutyl, hydroxypropyl, and hydroxypentyl, with mono- or diphosphoric acid esters of n-butyl or 2-ethylhexyl being particularly preferred. Examples of phosphorus acid salts include the above-mentioned phosphorus acid salts, such as potassium, sodium, lithium, calcium, zinc, aluminum, tin, barium, etc. salts, particularly potassium, sodium, or calcium salts. Secondary phosphates are preferred. Epoxy resin (A-1) and phosphoric acids (A-2)
The reaction with the epoxy resin is preferably carried out at a ratio such that the hydroxyl group of the phosphoric acid is 0.05 to 0.9 equivalent, preferably 0.05 to 0.4 equivalent, per equivalent of the epoxy group in the epoxy resin, and the resulting modified epoxy resin (precondensate) The epoxy equivalent of is preferably 3000 or less. The polyol resin (A) of the present invention is obtained by reacting such a precondensate with a compound (A-3) containing an amino group, such as a primary amine or a secondary amine; Particularly preferred as 3) is hydroxylamine containing a hydroxyl group. Examples of primary amines include methylamine, ethylamine, propylamine, etc.; examples of secondary amines include dibutylamine, etc.
Examples of hydroxylamine include ethanolamine, propanolamine, diethanolamine, and diisopropanolamine. The reaction ratio between the precondensate and the amino group-containing compound (A-3) is such that the ratio of groups that are reactive with epoxy groups in the latter to epoxy groups in the former is 1.1 to 0.7, particularly A ratio of 1.0 to 0.9 is preferable. The reaction between the precondensate and the amino group-containing compound (A-3) can be carried out without a catalyst at a temperature of, for example, 60 to 150°C. Examples of the compound (B) having more than one isocyanate group or a group that converts into isocyanate under curing conditions used in the present invention include toluene diisocyanate, xylylene diisocyanate,
Examples include crude diphenylmethane diisocyanate, hexamethylene diisocyanate, lysine diisocyanate methyl ester, a 3-mole toluene diisocyanate adduct of trimethylolpropane, and high molecular weight polyisocyanates (prepolymers) obtained therefrom. Compounds (B) with more than one isocyanate group or groups that convert to isocyanate under curing conditions
The blending ratio of the hydroxyl group equivalent and isocyanate group equivalent in the polyol resin (A) is 0.4 to 1.2,
The ratio is preferably 0.7 to 1.0. As the bituminous substance used in the composition of the present invention, coal tar, coal tar pitch, various types of cutback tar, swelling charcoal, asphalt, etc. can be used. In addition, there are various alternatives to bituminous substances, such as aromatic oil resins, coumaron resins, petroleum resins, and substances commonly used as diluents.
DOP, DBP, and other high-boiling point neutral oils such as petroleum-based and coal-based oils can be used. The blending ratio of bituminous substance and/or bituminous substance substitute (C) is polyol resin (A)
0.5 to 2 times the weight is appropriate. Incidentally, various curing catalysts, fillers, diluents, dehydrating agents, resins, etc. can be added to the composition of the present invention as necessary. Hereinafter, the present invention will be explained in more detail with reference to Examples.
Note that parts in the examples are based on weight. [Production Example 1] 100 parts of bisphenol A diglycidyl ether (epoxy equivalent = 260) and adeca glycilol
ED = 501 (epoxy equivalent = 300) 25 parts and xylene 33
1 part and 6 parts of orthophosphoric acid were mixed and reacted at 80°C for 5 hours, and the resulting precondensate was designated as [ ]. 22 parts of dibutylamine was added to 100 parts of the precondensate [ ] (solid content = 80%), and the mixture was stirred at 80°C for 2 hours to obtain a polyol resin ( ). The hydroxyl equivalent of the polyol resin (2) was 290. [Production Example 2] 100 parts of bisphenol A diglycidyl ether (epoxy equivalent = 470), 5 parts of monoethyl phosphate, and 35 parts of xylene were mixed and reacted with stirring at 90°C for 4 hours, and the resulting precondensate was []. 14 parts of diethanolamine was added to 100 parts of the precondensate [] (solid content = 75%), and the mixture was stirred at 70°C for 3 hours to obtain a polyol resin (). The hydroxyl equivalent weight of the polyol resin was 350. [Production Example 3] 100 parts of bisphenol F diglycidyl ether (epoxy equivalent = 280), 50 parts of diglycidyl ether of bisphenol A propylene oxide adduct (epoxy equivalent = 340), 70 parts of xylene, and secondary phosphoric acid Mix with 17 parts of potassium and heat at 110°C.
The precondensate obtained by stirring the reaction for a period of time is
shall be. 28 parts of diisopropanolamine was added to 100 parts of the precondensate [] (solid content = 70%), and the mixture was stirred at 80°C for 2 hours to obtain a polyol resin (). The hydroxyl equivalent of the polyol resin was 370. [Production Example 4] 100 parts of bisphenol A diglycidyl ether (epoxy equivalent = 260) and adeca glycilol
25 parts of ED-501 (epoxy equivalent = 300) and 30 parts of xylene
58 parts of dibutylamine were added thereto, and the mixture was stirred at 80°C for 2 hours to obtain a polyol resin (2). The hydroxyl equivalent of the polyol resin (2) was 210. [Production Example 5] 100 parts of bisphenol A diglycidyl ether (epoxy equivalent = 470), 55 parts of xylene and 22 parts of diethanolamine were added and stirred at 70°C for 3 hours to obtain a polyol resin (). The hydroxyl equivalent of the polyol resin (2) was 270. [Production Example 6] 100 parts of bisphenol F diglycidyl ether (epoxy equivalent = 280), 50 parts of glycidyl ether of bisphenol A propylene oxide adduct (epoxy equivalent = 340), 70 parts of xylene, and 67 parts of diisopropanolamine. was added and stirred at 80°C for 2 hours to obtain a polyol resin (). The hydroxyl equivalent of the polyol resin (2) was 190. Examples 1 to 6, Comparative Examples 1 to 6 Using the polyol resins () to () obtained in Production Examples 1 to 6 above, compositions having the compositions shown in Tables 1 and 2 were obtained. The coating film performance test results of such compositions are shown in Tables 1 and 2.

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Claims (1)

[Claims] 1. A precondensate obtained from a phosphorus acid having at least one P-OH bond, its ester or salt, and an epoxy resin contains an amino group reactive with an epoxy group as an essential component. A polyol resin (A) obtained by reacting a compound with a compound (B) containing more than one isocyanate group or a group that converts into isocyanate under curing conditions.
and a bituminous material and/or its substitute (C).