JPS6312105B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a coating composition that can be rapidly cured even at room temperature to -20°C. In recent years, epoxy resin paints using polyamine hardeners have been widely used for the purpose of waterproofing and corrosion resistance. However, epoxy resin coatings using such polyamine curing agents have the disadvantage that curing hardly progresses and no coating film is formed in winter, especially when the outside air temperature drops below 0°C. On the other hand, as curing agents for epoxy resins, isocyanate-based curing agents are known in addition to polyamine-based curing agents. This isocyanate curing agent is
Although it is superior to polyamine curing agents in terms of low-temperature drying properties, it has the disadvantage that it is easily affected by moisture in the atmosphere during curing, and the waterproof and corrosion resistance of the formed coating film is impaired. In addition, as a modified version of epoxy resin paint, a composition consisting of epoxy resin, oligoester acrylate, and polyamine (Japanese Unexamined Patent Application Publication No. 51-197) is available.
101100), a composition containing as a component a reaction product of an epoxy compound and an α,β-unsaturated carboxylic acid to which a polyamine is added (Japanese Patent Laid-Open Publication No. 1973-
No. 95919) and the like have been proposed, but all of them produce cloudy coatings when cured at low temperatures, and are not satisfactory. The present inventors have conducted extensive research with the aim of eliminating the drawbacks of conventional epoxy resin coating compositions, and as a result, have completed the present invention. That is, the present invention provides (A) an epoxy equivalent of 100 to
1500 epoxy resin, (B) epoxy equivalent 100-1500
Epoxy acrylate obtained by the reaction of epoxy resin with acrylic acid, (C) Epoxy equivalent
Epoxy acrylate obtained by reacting an epoxy resin with an epoxy equivalent weight of 100 to 1500 and/or an epoxy resin with an epoxy equivalent weight of 100 to 1500 with acrylic acid, and a fat having at least two primary amino groups in one molecule. This is a low-temperature curable coating composition comprising a modified polyamine obtained by reacting with at least one type of polyamine, alicyclic polyamine, or aromatic polyamine. The epoxy resin used as the component (A), component (B), and component (C) of the present invention is, for example,
Published in 1969, written by Kuniyuki Hashimoto, “Epoxy Resin” No. 2
Among the known epoxy resins as described in Chapter
100-1500. Preferably 150-1000
belongs to. Examples of such epoxy resins include condensates of epichlorohydrin or methylepichlorohydrin and phenolic compounds. Examples of phenolic compounds in this case include 2,2'-bis(4,4'-hydroxyphenyl)propane (commonly known as bisphenol A), halogenated bisphenol A, and 2,2'-bis(4,4'-hydroxyphenyl)propane (commonly known as bisphenol A). ，
Examples include bisphenols such as 4'-hydroxyphenyl)methane (commonly known as bisphenol F), novolak-type polyfunctional phenols obtained by condensing formalin with phenol or cresol, and tetrahydroxyphenol. Other aromatic or alicyclic compounds such as diglycidyl ether of polyalkylene glycol such as polypropylene glycol, hexahydrophthalic acid diglycidyl ester, phthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, methylhexahydrophthalic acid diglycidyl ester, etc. Examples include glycidyl esters, dimer acid glycidyl esters, and glycidyl amines obtained from hydantoin, which is a mononuclear nitrogen-containing heterocyclic compound having an internal cyclic imino group. This epoxy resin needs to have an epoxy equivalent of 100 to 1,500, preferably 150 to 1,000. If it is less than 100 epoxy equivalent, it is not suitable because it has poor compatibility with other components and the corrosion resistance of the obtained coating film is poor, and if it is more than 1500 epoxy equivalent, the strength of the coating film is constant. It takes a long time to reach this point, which is inappropriate. Preferably,
Component (A), component (B), and component (C) are all epoxy resins obtained by condensation of bisphenol A and epichlorohydrin, each having an epoxy equivalent weight of 180 to 500. The epoxy acrylate used as component (B) of the present invention is obtained by reacting at least one epoxy group in one molecule of the epoxy resin with acrylic acid, and is an epoxy acrylate similar to the component (A). A resin and acrylic acid are combined in the presence of at least one polymerization inhibitor selected from monovalent or polyvalent phenols and quinones and an esterification catalyst such as lithium halide or tertiary amine. , can be obtained by heating reaction without causing gelation. The ratio of the epoxy resin and acrylic acid in this case is about 0.2 to 1.0 equivalents of carboxyl groups in acrylic acid to 1 equivalent of epoxy groups in the epoxy resin. The modified polyamine used as component (C) of the present invention has at least two or more primary amino groups in one molecule together with the epoxy resin as the component (A) and/or the epoxy acrylate as the component (B). It is obtained by reacting with at least one type of aliphatic, alicyclic, and aromatic polyamine. The above polyamine has at least two or more primary amino groups in one molecule,
For example, aliphatic polyamines such as ethylenediamine, diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine, hexaethyleneheptamine, hexamethylenediamine, dipropylenetriamine,
Aromatic amines such as xylylene diamine, diaminodiphenylmethane, diaminodiphenyl sulfone, and phenylene diamine, and alicyclic polyamines such as cyclohexylaminopropylamine, isophorone diamine, menthanediamine, and N-aminoethylpiperazine. Can be done. Preferred are polyalkylene polyamines, and particularly preferred are diethylenetriamine and triethylenetetramine. In component (C), the ratio of epoxy resin to epoxy acrylate is 100:0 to 20:80 by weight.
is preferred. Usually, the epoxy resin as the component (A) and the epoxy acrylate as the component (B) are used in an equal weight ratio. In component (C), the reaction between the epoxy resin and/or epoxy acrylate and the polyamine is
For each equivalent of the epoxy group alone in the epoxy resin, the acryloyl group alone in the epoxy acrylate, and the total of the epoxy group in the epoxy resin and the acryloyl group in the epoxy acrylate, the primary Amino group 1.0~
It can be obtained by reacting in a range of 5.0 equivalents, preferably in a range of 1.5 to 3.0 equivalents. If the primary amino group in the polyamine is less than 1.0 equivalents, it will take a long time for the strength of the coating film to reach a certain level, making it impossible to achieve the objective of the present invention, and if it is more than 5.0 equivalents, the coating film cured at low temperatures may It tends to become cloudy and causes a decrease in corrosion resistance. This reaction can be easily produced, for example, by mixing and stirring an epoxy resin and an epoxy acrylate while simultaneously or sequentially dropping them into a polyamine solution. In the present invention, the mixing ratio of the epoxy resin as the component (A) and the epoxy acrylate as the component (B) is
per 100 parts by weight, the latter is 10 to 1000 parts by weight,
Preferably it is 50 to 200 parts by weight. When component (B) is less than 10 parts by weight, it takes a long time to reach a certain level of strength at low temperatures below 0°C, and when it is more than 1000 parts by weight, the corrosion resistance of the resulting coating film is significantly impaired. The modified polyamine of the component (C) of the present invention is the same as the component (A).
When added to a mixture of component (B), the active hydrogen atom of component (C) is 0.5 to 2.0, preferably 0.8 per equivalent of the total of epoxy groups and acryloyl groups in component (A) and component (B). Must be added to ~1.2 equivalents. If the active hydrogen equivalent of component (C) is less than 0.5 equivalent, low temperature curability is insufficient and it takes a long time for the strength to reach a certain level. If the amount is more than 2.0 equivalents, the resulting coating film will remain sticky, impairing its anticorrosion properties. Component (C) of the present invention is preferably added at the time of use of the coating composition; if mixed several hours or more before use, low-temperature curability and low-temperature compatibility will be impaired, resulting in a poor coating film. Difficult to form. In addition to the above-described components (A), (B), and (C), accelerators, diluents, fillers, reinforcing agents, fillers, pigments, etc. may be added to the present invention as necessary. Can be done. Examples of accelerators that can be added include compounds with a tertiary amino group such as dimethylbenzylamine, 2,4,6-tridimethylaminomethylphenol, and triethylenediamine, or compounds with a hydroxyl group such as phenol, cresol, and furfuryl alcohol. Compounds with It is desirable to add these at the time of use of the coating composition. Further, as the diluent, aromatic hydrocarbons such as xylene and toluene, ketones such as methyl ethyl ketone and methyl isobutyl ketone, and esters such as ethyl acetate and ethyl propionate are used. Examples of other additives include glass fiber,
Asbestos fibers, boron fibers, carbon fibers, cellulose, polyethylene powder, quartz powder, mineral silicates such as mica, asbestos powder and slate powder,
Kaolin, aluminum oxide, aluminum hydroxide, clay, antimony trioxide, silica, barite, zeolite, titanium dioxide, talc, carbon black, graphite, oxide color pigments (e.g. iron oxide), or metal powders (e.g. iron powder). , aluminum powder), bituminous materials such as asphalt, pitch oil, and swollen coal tar can be added as appropriate and necessary. The composition of the present invention is useful for civil engineering, including pavement coatings for roads or airport runways, anti-slip coatings for concrete, asphalt, wood, steel, etc., building materials, steel pipes, transportation equipment including ships and automobiles. , protective paints such as Hashiyo, etc. The composition of the present invention cures quickly even at a low temperature of -20°C, and provides a coating film with an arbitrary thickness of 10 μm to 1 cm.
Its curing is not inhibited by the presence of moisture, and its salt spray resistance is also very good. The present invention will be explained in more detail below using examples. All numbers in Examples and Comparative Examples represent parts by weight. Production of epoxy acrylate 190 parts of bisphenol A diglycidyl ether (manufactured by Asahi Kasei Corporation, trade name AER-331) (hereinafter referred to as epoxy resin A) having an epoxy equivalent of 190, a molecular weight of 380, and a viscosity of 140 poise (25°C) is mixed with 190 parts of acrylic acid
70 parts were reacted to obtain epoxy acrylate (hereinafter referred to as epoxy acrylate A) having an acid value of 1.0 mgKOH/g. Production of epoxy acrylate 475 parts of bisphenol A diglycidyl ether (manufactured by Asahi Kasei Corporation, trade name: AER-661) (hereinafter referred to as epoxy resin B) having an epoxy equivalent of 475, a molecular weight of 950, and a softening temperature of 68°C is added to 475 parts of acrylic acid. 70 parts were reacted to produce a compound having an acid value of 0.5 mgKOH/g, and then 185 parts of toluene was added thereto to obtain epoxy acrylate (hereinafter referred to as epoxy acrylate B). Production of modified polyamine: 154 parts of triethylenetetramine and epoxy resin
A190 part is reacted with modified polyamine (hereinafter referred to as
A modified polyamine A) was obtained. (Theoretical active hydrogen equivalent: 68.8) Production of modified polyamine 103 parts of diethylenetriamine and epoxy resin
287 parts of B and 65 parts of butyl glycidyl ether were reacted to form a modified polyamine (hereinafter referred to as modified polyamine B).
). (Theoretical active hydrogen equivalent: 102) Production of modified polyamine Add 103 parts of diethylenetriamine to epoxy resin
Modified polyamine (hereinafter referred to as modified polyamine C) is produced by reacting 95 parts of A with 131 parts of epoxy acrylate A.
). (Theoretical active hydrogen equivalent: 82.3) Production of modified polyamine 136 parts of xylylene diamine and epoxy resin B164
224 parts of epoxy acrylate A were reacted to obtain a modified polyamine (hereinafter referred to as modified polyamine D). (Theoretical active hydrogen equivalent: 152) Example 1 20 parts of epoxy acrylate A was mixed with 20 parts of epoxy resin A, and the mixture was diluted with 10 parts of toluene. Next, this mixture was added with modified polyamine A13.5.
10 parts and 10 parts of toluene were added to dissolve and mix uniformly.
It was applied to a thickness of 1 mm on a mild steel plate under conditions of ℃. The applied composition was dry to the touch in about 5 hours. The obtained coating film had a good surface condition without cloudiness or unevenness, and the physical properties of the coating film measured one week later were as follows. Pencil hardness H Erichsen 8 mm or more Salt water spray resistance 500 hours No abnormality Comparative example 1 Epoxy acrylate in 20 parts of epoxy resin A
20 parts of A were mixed and diluted with 10 parts of toluene. Next, 4 parts of triethylenetetramine and 10 parts of toluene were added as a hardening agent to this mixture, and the mixture was uniformly dissolved.
The mixture was mixed and applied to a thickness of 1 mm on a mild steel plate at 0°C. The applied composition cured after 5 hours, but the surface was cloudy and remained sticky even after one week had passed. Salt water spray test measured after one week
Blistering occurred after 100 hours. Comparative Example 2 Epoxy resin A, epoxy acrylate A, and modified polyamine A were blended as shown in Table 1, and coated in the same manner as in Example 1. As a result, it was not possible to obtain a good coating film in any case.

[Table] Example 2 Using epoxy resin B, epoxy acrylate B, and modified polyamine B, a two-component paint containing a main agent and a curing agent was prepared with the formulation shown in Table 2, and -
After mixing at 10°C, the mixture was applied onto a mild steel plate to a dry film thickness of 500μ, and the drying time of the film and the performance of the film after one week were examined. Both are 5
The resulting coating film was dry to the touch in about 10 hours, had a good surface condition without cloudiness or unevenness, and had excellent coating performance.

[Table] Comparative Example 3 In Experiment No. 3 of Example 2, epoxy
Acrylate B and modified polyamine B were mixed at -5°C. After one day, add epoxy resin B to the mixture.
When mixed, it did not harden and remained sticky even after one week. Example 3 A paint was prepared with the formulation shown in Table 3, and after mixing the main agent and curing agent at 0°C, it was sprayed onto a mild steel plate to a dry film thickness of 500μ. The coating film cured quickly, and the surface condition and performance of the coating film after one week were also excellent.

【table】

Claims (1)

[Claims] 1. (A) An epoxy resin having an epoxy equivalent of 100 to 1,500, (B) An epoxy resin obtained by reacting an epoxy resin with an epoxy equivalent of 100 to 1,500 with acrylic acid.
Acrylate, (C) Epoxy acrylate obtained by reacting an epoxy resin with an epoxy equivalent of 100 to 1,500 and/or an epoxy resin with an epoxy equivalent of 100 to 1,500 with acrylic acid, and a primary amino group in one molecule. It consists of a modified polyamine obtained by reacting with at least one type of aliphatic, alicyclic or aromatic polyamine having at least two or more polyamines, and the weight of component (B) per 100 parts by weight of component (A) is 10 to 1000 parts by weight, and active hydrogen in component (C) is 0.5 to 2.0 equivalents per equivalent of the total of epoxy groups and acryloyl groups in components (A) and (B). A low temperature curable coating composition. 2 Claims in which the epoxy resin used for component (A), component (B), and component (C) is a condensate of 2,2'-bis(4,4'-hydroxyphenol)propane and epichlorohydrin. The composition according to item 1. 3 Component (C) is an epoxy resin having an epoxy equivalent of 100 to 1,500, an epoxy acrylate obtained by reacting an epoxy resin with an epoxy equivalent of 100 to 1,500, and acrylic acid, and the weight ratio is 100:0 to 20:80. It is characterized by being obtained by reacting a mixed resin with at least one type of aliphatic, alicyclic, or aromatic polyamine having at least two or more primary amino groups in one molecule. Claim 1
Compositions as described in Section. 4. Component (C) is reacted in a range of 1.0 to 5.0 equivalents of primary amino groups in the polyamine with respect to 1 equivalent of the epoxy group in the epoxy resin and the acryloyl group in the epoxy acrylate. 3. The composition according to claim 3 obtained in this manner.