JPH0463910B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a high curing speed, hardly causes amine brushing phenomenon, and can be made solvent-free.
The present invention relates to an anticorrosion coating composition that also has excellent anticorrosion performance. Epoxy resins are widely used as anticorrosion paints for metals, but currently paints in which a unique epoxy resin and a hardening agent are dissolved in a solvent are mainly used. However, in recent years, attempts have been made to use solvent-free materials for the purpose of making them pollution-free and increasing corrosion resistance 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 reaction product in which a monovalent phenol is reacted with a reaction product of a polyhydric phenol and epichlorohydrin, or a reaction product in which a polyhydric phenol, a monovalent phenol, and epichlorohydrin are simultaneously reacted, (B) an amino compound having two or more active hydrogen atoms in one molecule; and (C) an anticorrosive coating composition characterized by containing an anticorrosive pigment as an essential component. (Hereinafter, % by weight is simply referred to as %.) The liquid epoxy resin (A) used in the present invention can be prepared by adding an appropriate monovalent phenol to a reaction product of an appropriate polyhydric phenol and epichlorohydrin, or by further reacting it. It is obtained by simultaneously reacting polyhydric phenol, monohydric phenol, and epichlorohydrin. As the catalyst, sodium hydroxide, lithium salt, calcium salt, tertiary amine, quaternary ammonium salt, etc. can be used. The main component of the resulting resin is a mixture of (1), (2), and (3) below. -O-R-O-: Polyvalent phenol residue O-R': Monovalent phenol residue Polyvalent phenols include resorcinol, hydroquinone, bis(4-hydroxyphenyl)methane,
Contains two or more phenolic hydroxyl groups in the molecule, such as 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), and does not contain any other functional groups that would prevent glycidyl ether formation. It is something. A typical example is bisphenol A. Monovalent phenols contain one phenolic hydroxyl group in the molecule, and may be mononuclear or polynuclear, and may be substituted with other groups. Examples of monovalent phenols include phenol, p-vinylphenol, p-tert-butylphenol, p-tert-octiphenol, 3,5-dimethylphenol, p-
Examples include chlorphenol. The amount of monohydric phenol to be reacted needs to be in the range of 3 to 15% based on the total epoxy resin. When the amount is less than 3%, the curing speed is not much different from that of ordinary epoxy resins, and when it is more than 15%, the performance of the cured product decreases. Even if epoxy resins containing different amounts of monovalent phenol are mixed and used, there is no problem as long as the amount of monovalent phenol 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 comprising the above-mentioned essential components (A) to (C) exhibits the following characteristics in contrast to a composition using a conventional liquid epoxy resin in place of (A). 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. In addition to the above-mentioned essential components (A) to (C), pigments, additives, and other auxiliary paint materials may be appropriately added to the composition of the present invention, as desired. Examples of pigments and additives 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, the present invention will be explained in detail with reference to Examples. In the examples, parts indicate parts by weight. Example 1 100 parts of bisphenol A diglycidyl ether type epoxy resin (Asahi Kasei Corporation, trade name AER 330) with an epoxy equivalent of 185 was heated and stirred, and 0.03 part of a 10% sodium hydroxide aqueous solution was added at 80°C to make it homogeneous. mixed with. Next, 10 parts of p-tert-butylphenol was added, and while stirring, the temperature was raised to 145° C. and maintained for 6 hours to react. The epoxy equivalent weight of the reactant was 232. Add and mix 100 parts of glass flakes to 100 parts of the above reactant, and add 15 parts of xylylene diamine (ratio of 1 equivalent of epoxy group to 1 equivalent of active hydrogen of the amine. Hereinafter, the amount of amine added is the same. ) was added, 59g of it was taken, and the time required for gelation to occur at room temperature was measured, and it was 35 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 2 100 parts of AER330, p-tertiary octylphenol
A reaction product was obtained in the same manner as in Example 1 using 14 parts. The epoxy equivalent was 238. 100 parts of glass flakes were mixed with 100 parts of the reactant, 14 parts of xylylene diamine was added, and the gelation time and brushing state were examined in the same manner as in Example 1. Gel time is 39
However, almost no whitening was observed due to amine brushing. Comparative Example 1 The same procedure as in Example 1 was performed except that AER330 was used instead of AER330 reacted with monovalent phenol, and 18 parts of xylylene diamine was used instead of 15 parts of xylylene diamine. The time was 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, 2, and 3 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. 【table】

Claims (1)

[Scope of Claims] 1 (A) A reaction product obtained by reacting a reaction product of a polyvalent phenol and epichlorohydrin with a monovalent phenol, or a reaction product obtained by simultaneously reacting a polyvalent phenol, a monovalent phenol, and epichlorohydrin, , a liquid polyhydric phenol glycidyl ether type epoxy resin in which the proportion of the monohydric phenol reacted above is 3 to 15% by weight of the entire reactant; (B) an amino compound having two or more active hydrogens in one molecule; , and (C) an anticorrosive coating composition, characterized in that it contains an anticorrosive pigment as an essential component.