JPH0465107B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention has a fast curing speed, hardly causes amine brushing phenomenon, and can be made solvent-free.
The present invention relates to an anticorrosive coating composition that also has excellent anticorrosion performance. Epoxy resins are widely used as anticorrosive paints for metals, but currently, paints in which a solid epoxy resin and a hardening agent are dissolved in a solvent are mainly used. However, in recent years, attempts have been made to make it solvent-free for the purpose of making it non-polluting and strengthening anti-corrosion properties through thick coating. Solvent-free use can be achieved by using liquid epoxy resin, but there are dissatisfaction with the curing speed and amine brushing properties, and there is a strong demand for anticorrosive paints that have a faster curing speed and are less likely to cause amine brushing. Ta. The inventors conducted research into a coating composition that has a faster curing speed than when ordinary liquid epoxy resins are used, is less likely to cause amine brushing, and has excellent anticorrosion performance, and has arrived at the present invention. It is something. That is, the present invention provides (A) a terminal containing 0.4 to 0.4 to 0.4 to halogen
An anticorrosive paint characterized by containing a liquid epoxy resin in the range of 2.0% by weight, (B) an amino compound having two or more active hydrogens in one molecule, and (C) an anticorrosive pigment as essential components. It is a composition. Hereinafter, weight % is simply written as %. The liquid epoxy resin (A) used in the present invention includes:
Any material may be used as long as it has two or more epoxy groups in one molecule, is liquid at room temperature, and contains 0.4 to 2.0% by weight of halogen that can be eliminated by hydrolysis. Preferred epoxy resins include, for example, 2,2-bis(4-hydroxyphenyl)
It is a diglycidyl ether produced by the reaction of diphenylloroalkane such as propane or bis(4-hydroxyphenyl)methane and epihalohydrin.
A typical example is diglycidyl ether of 2,2-bis(4-hydroxyphenyl)propane (bisphenol A). In addition, polyglycidyl ethers of aliphatic polyhydroxy compounds, polyglycidyl esters of polyvalent carboxylic acids, polyglycidyl esters of polymers of unsaturated fatty acids, etc. can also be used. Halogens that can be eliminated by hydrolysis are, for example, halogens that can be removed by reacting a compound with a hydroxyl group with epihalohydrin to introduce an epoxy group according to the following formulas (1) and (2). The reaction progresses, but the reaction of formula (2) is not completed and it refers to the halogen that remains in the form of formula (1), and is eliminated as shown in formula (2) by hydrolysis with an alkali. . Hereinafter, this halogen will be referred to as a hydrolyzable halogen. Since epichlorohydrin is generally used as epihalohydrin, the halogen is often chlorine. X: Halogen The amount of hydrolyzable halogen can be controlled by the amount of alkali added during the reaction of formula (2). The following method is exemplified as a method for measuring the amount of hydrolyzable halogen. (1) Precisely weigh 6 to 8 g of the sample into a 300 ml Erlenmeyer flask, add 50 ml of a solution of 6 g of potassium hydroxide dissolved in 15 ml of toluene and 1000 ml of ethanol, and heat and stir with a condenser attached. (2) Heat under reflux for 10 minutes and cool to room temperature. (3) Titrate with 1/10 N hydrochloric acid aqueous solution using phenolphthalein as an indicator. (4) Calculate the amount of hydrolyzable halogen according to the following formula. Amount of hydrolyzable halogen (%) = 0.1 x f x (Q-S) x M/10W W: Weight of sample (g) f: Potency of 1/10 normal hydrochloric acid aqueous solution Q: 1/10 normal in blank test Titration amount of hydrochloric acid aqueous solution (ml) S: Titration amount of 1/10 normal hydrochloric acid aqueous solution (ml) M: Atomic weight of halogen The above titer is a correction factor for the concentration of the titrant used in volumetric analysis. The true specified concentration of this standard solution can be obtained by multiplying the titer by the tentative specified concentration (in this case, specified as 1/10) displayed on a commercially available standard solution reagent. When the amount of hydrolyzable halogen is less than 0.4%, the curing speed is not much different from that of ordinary liquid epoxy resin, but when it is more than 2.0%, the performance of the cured product decreases, so it is necessary to keep it in the range of 0.4 to 2.0%. . Even if epoxy resins having different amounts of hydrolyzable halogen are mixed and used, there is no problem as long as the amount of hydrolyzable halogen in the mixture is within the above range. As the amino compound B having two or more active hydrogens in one molecule used in the present invention, aliphatic polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine, isophoronediamine, menthanediamine, N-aminomethyl Alicyclic aliphatic polyamines such as piperazine, aromatic amines and heterocycle-containing polyamines such as xylylene diamine, phenylene diamine, diaminodiphenylmethane, diaminodiphenylsulfone, and modified polyamines modified from these amines, natural or synthetic. Examples include polyamide amines synthesized from dicarboxylic acids and polyamines such as ethylenediamine. (B) has active hydrogen equivalents of 0.5 to 2.0 equivalents, preferably 0.6 to 1.5 equivalents, per equivalent of the epoxy group in (A).
It is best to use them in proportions that give equivalent amounts. The antirust pigment (C) used in the present invention includes basic pigments such as red lead, lead zinc oxide, lead cyanamide, basic lead sulfate, calcium leadate, and zinc white, zinc chromate, strontium chromate, and basic chromate. Examples include soluble pigments such as lead and lead phosphate, metal powders such as zinc powder and aluminum powder, metal oxides such as iron oxide, and inorganic powders such as glass flakes and mica powder. The composition of the present invention consisting of the above essential components (A) to (C) has a hydrolyzable halogen content of 0.4% instead of (A).
The following characteristics are exhibited for compositions using less liquid epoxy resin. Curing speed is extremely fast. Absorbs moisture in the air and causes the paint film to whiten.
The so-called amine brushing phenomenon is less likely to occur. The adhesion and corrosion resistance of the paint film are the same. Due to its characteristics, the composition of the present invention can provide a beautiful, solvent-free coating film with excellent anticorrosion performance to metal surfaces in a short time, and is effective in preventing corrosion of steel materials, steel, structures, etc. do. Typical applications include protection of civil engineering and construction materials such as pavement coverings for roads and airport runways, anti-slip coverings of concrete, asphalt, wood, steel, etc., steel pipes, ships, automobiles, structures, bridges, steel frames, etc. Examples include paint and the like. In addition to the above-mentioned essential components (A) to (C), pigments, additives, other paint auxiliary materials, etc. can be appropriately added to the composition of the present invention, as desired. Pigments, additives and examples include glass fiber, asbestos fiber, carbon fiber, cellulose, polyethylene powder, kaolin, aluminum oxide, aluminum hydroxide, silica, barite, zeolite, titanium dioxide, talc, carbon black,
Examples include graphite, organic colored pigments, and various dispersants. In addition, examples of auxiliary materials for paint include asphalt, coal tar, coal tar pitch, various plasticizers, petroleum resins, coumaron resins, xylene resins, ketone resins, and the like. The composition of the present invention can be used without a solvent, but a solvent may be added depending on the use. As the solvent, aromatic hydrocarbons such as xylene and toluene, ketones such as methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate and isobutyl acetate, cellosolves, etc. can be used. Hereinafter, it will be explained in detail using examples. In the examples, parts indicate parts by weight. Example 1 Bisphenol A diglycidyl ether containing 1.6% hydrolysable chlorine (epoxy equivalent 209,
Add 100 parts of glass flakes to 100 parts (viscosity: 17,500 cps) and mix, and to this add 16 parts of xylylene diamine (ratio of 1 equivalent of epoxy group to 1 equivalent of active hydrogen of the amine.The amount of amine added is the same below). ) was added, 50g of it was taken, and the time required for gelation to occur at room temperature was measured, and it was 25 minutes. When this composition was applied to a thickness of 200 μm on a mild steel plate and left to cure at room temperature for 7 days, almost no whitening due to the amine brushing phenomenon was observed in the coating film. Example 2 Bisphenol A diglycidyl ether with epoxy equivalent of 189 (viscosity 14000 cps, hydrolyzable chlorine content 0.05%, manufactured by Asahi Kasei Corporation, trade name AER331) 38
and 62 parts of bisphenol A diglycidyl ether containing 1.6% of hydrolyzable chlorine were mixed to obtain a composition containing 1.0% of hydrolyzable chlorine. 50 parts of zinc powder was added to 100 parts of this composition and mixed, 12 parts of triethylenetetramine was added thereto, and the gelation time was measured in the same manner as in Example 1 and found to be 20 minutes. When this composition was formed into a coating film in the same manner as in Example 1 and left at room temperature for 7 days, almost no whitening due to the amine brushing phenomenon was observed. Comparative Example 1 Instead of 100 parts of bisphenol A diglycidyl ether containing 1.6% of hydrolyzable chlorine
Using 100 parts of AER331, xylylene diamine 16
The same procedure as in Example 1 was carried out except that 18 parts of xylylene diamine was used instead of 1 part, and the gelation time was
It was hot in 85 minutes. Further, the coating film had significant cloudiness due to the amine brushing phenomenon. Example 3 The physical properties of the coating films of Examples 1 and 2 and Comparative Example 1 were measured. The results are shown in Table 1. As for performance, it can be seen that they are all equivalent.

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Claims (1)

[Claims] 1 (A) A halogen X which can be eliminated by a hydrolysis operation represented by the following formula is present at the terminal.
A liquid epoxy resin containing in the range of 0.4 to 2.0% by weight, (B) an amino compound having two or more active hydrogens in one molecule, and (C) a rust preventive pigment as essential components. Anticorrosion paint composition.