JPH028789B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a coating method for forming an anticorrosive coating on plants, ships, etc. [Prior art] An epoxy resin undercoat film is formed on a base material such as metal, and then a solvent-type oil-modified alkyd resin paint or an air-drying solvent-free oil-modified alkyd resin paint that is capable of radical polymerization and oxidative polymerization is applied. It is known that a heavy anticorrosion coating film can be formed by coating and drying at room temperature (Japanese Patent Application Laid-open Nos. 59-123572 and 59-123573,
(See Publication No. 59-13270). The latter solvent-free oil-modified alkyd resin paint has the advantage of providing a thick film with excellent bending resistance and corrosion resistance compared to solvent-based paints. [Problems with the prior art] This painting method using epoxy resin undercoat paint does not cause any problems from spring to autumn, but when painting is carried out during the severe cold period of winter (temperature is 5 degrees Celsius or less),
It was observed that peeling occurred between the epoxy resin base coat film and the oil-modified alkyd resin film, and a lifting (so-called lifting) phenomenon occurred. The cause of such lifting is that when an oil-modified alkyd resin paint that cures at room temperature through radical polymerization is applied directly onto an epoxy resin undercoat film containing an amine-based hardener, unreacted amines, which are the epoxy resin hardener in the undercoat, are applied. It is assumed that this is caused by the sudden decomposition of peroxide, which is a radical polymerization initiator in oil-modified alkyd resin paints, resulting in poor curing of oil-modified alkyd paints (Japanese Patent Publication No. 13270/1983). There is a theory that According to our tests, even if the undercoat epoxy resin film is insufficiently cured, when an oil-modified alkyd resin topcoat is applied on top of this undercoat, no lifting is observed in the topcoat. However, when applying the top coat many times to obtain a thick coating film, if the first coat applied is not sufficiently cured (it feels dry to the touch), the second coat is applied. It was found that lifting occurs when topcoating is applied. In order to prevent this, even if the amount of cobalt naphthenate, which is a drying agent, is increased, the drying properties of the surface coating film are excellent, but the inside of the coating film is uncured.
It has been found that lifting cannot be prevented when the second top coat is applied. [Specific measures to solve the problem] The problem of lifting during thick coating in winter can be solved by blending a specific metal dryer mixture into the oil-modified alkyd resin paint to balance the hardening of the inside and surface of the paint film. It can be solved by doing it well. [Structure of the Invention] The present invention applies an epoxy resin undercoat containing an amino curing agent to a metal base material such as a plant or ship, dries it to form an undercoat film, and then applies the following metal The undercoat film is coated with a top coat in which a desiccant mixture is blended in an amount of 0.3 to 3 parts by weight based on 100 parts by weight of a room-temperature curable, solvent-free oil-modified alkyd resin coating composition capable of radical polymerization and oxidative polymerization. The present invention provides a method for forming an anticorrosive coating film, which is characterized by coating the coating material on the surface of the anticorrosion coating and drying it to form a cured coating film. Metal desiccant mixtures: (a) cobalt salts of organic carboxylic acids;
0.01 to 1 part by weight (metal content) (b) Lead salt of organic carboxylic acid
0.01 to 1 part by weight (metal content) (c) Organic carboxylate of a metal selected from manganese, calcium, zirconium, and iron
0.0001 to 1 part by weight (metal content). [Oil-modified alkyd resin] The oil-modified alkyd resin as a component of the oil-modified alkyd resin composition according to the present invention is essentially the same as oil-modified alkyd resins that are conventional or will be provided in the future (α, β- It also includes those further modified with unsaturated monocarboxylic acids.The method of modification with α,β-unsaturated monocarboxylic acids is the same as the method of modifying ordinary alkyd resins with fatty acids). Therefore, the polybasic acid components of the alkyd resin include phthalic anhydride, isophthalic acid, tetrahydrophthalic anhydride, adipic acid, sebacic acid, azelaic acid, various conjugated double bond-containing isoprene dimers, and maleic anhydride. 1,2,3, having a side chain obtained by the Diels-Alder addition reaction of
6-tetrahydrophthalic anhydride derivatives such as myrcene maleic anhydride, alloocimene maleic anhydride, ocimene maleic anhydride, 3-(β
-methyl-2-butenyl)-5-methyl-1,
2,3,6-tetrahydrophthalic acid, hexahydrophthalic anhydride, 4-methyl-1,2,3,6-
Aromatic, aliphatic or alicyclic saturated or unsaturated polybasic acids such as tetrahydrophthalic anhydride and trimellitic acid are used alone or in combination. As long as gelation does not occur, part of the saturated polybasic acid may be replaced with an α,β-unsaturated polybasic acid such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, etc.
Among these, particularly preferred polybasic acids are phthalic acid and 3-(β-methyl-2-butenyl)-5
-Methyl-1,2,3,6-tetrahydrophthalic anhydride (hereinafter abbreviated as MBTHP). When MBTHP is used as part of the polybasic acid, it has a remarkable effect on reducing the viscosity of alkyd resins. Polyhydric alcohol components include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, neopentyl glycol, glycerin, pentaerythritol, trimethylolpropane, trimethylolethane, and tris(2-hydroxyethyl). Isocyanurate etc. are used alone or in combination. Generally, dihydric to tetrahydric alcohols having about 2 to 12 carbon atoms are common. The oil or fatty acid forming the oil-modified alkyd resin includes those having air-drying properties, such as oils and fats such as linseed oil, soybean oil, tall oil, and safflower oil, or fatty acids separated therefrom. In the present invention, it is preferable to further modify the oil-modified alkyd resin consisting of the three essential components with an α,β-unsaturated monocarboxylic acid. α used here,
β-unsaturated monocarboxylic acids are crotonic acid, sorbic acid or 2-(β-furyl)acrylic acid. Particularly preferred among these is sorbic acid. These α,β-unsaturated monocarboxylic acids introduced into the oil-modified alkyd resin are thought to react in the same way as oil-modified fatty acids and exist as side chains in the alkyd resin, but these acids are When a polymerizable monomer is used as component (B) in the composition of the invention, it radically copolymerizes with it and contributes to curing, resulting in a significant effect on improving the hardness and corrosion resistance of the resulting coating film. Oil-modified alkyd resins are produced from these three essential components or four components by conventional methods. Specifically, for example, α,β-unsaturated monocarboxylic acid,
There is a method in which a fatty acid, a polybasic acid, and a polyhydric alcohol are simultaneously charged and reacted, or a method in which a fatty acid, a polybasic acid, and a polyhydric alcohol are first reacted, and then an α,β-unsaturated monocarboxylic acid is reacted therewith. The latter is preferred from the viewpoint of preventing gelation during production. These components can be subjected to the reaction in the form of their functional derivatives, such as esters such as fats and oils themselves. When using fats and oils, it is common to carry out transesterification by reacting only the polyhydric alcohol with the fats and oils in advance. Furthermore, in any method, it is desirable to add an antigelation agent such as hydroquinone to avoid gelation during the reaction. The oil-modified alkyd resin used in the present invention has an oil length of 30 to 70%, preferably 55 to 65%. Aburanaga
If it is less than 30%, it causes a decrease in the water resistance etc. of the resulting coating film, while if it is more than 70%, undesirable phenomena such as a decrease in the initial drying hardness of the resulting coating film and a decrease in surface smoothness occur. Note that the oil length in the present invention is the weight percent of the monobasic acid triglyceride derived from the oil or fatty acid separated from the oil or fat in the oil-modified alkyd resin after modification with an α,β-unsaturated monocarboxylic acid. The α,β-unsaturated monocarboxylic acid content in the α,β-unsaturated monocarboxylic acid-modified oil-modified alkyd resin used in the present invention is 0.5 to 30% by weight, preferably 2 to 15% by weight. . If it is less than 0.5%, no effect of improving the water resistance and hardness of the resulting coating film can be expected; on the other hand, if it exceeds 30%, the alkyd will be extremely prone to gelation during production, making its production difficult. The acid value of the oil-modified alkyd resin or α,β-unsaturated monocarboxylic acid-modified oil-modified alkyd resin used in the present invention is usually about 5 to 40. [Diluent] The oil-modified alkyd resin of component (A) has a high viscosity and is difficult to coat as it is, so it is used after being diluted with a polymerizable monomer that dissolves component (A). If necessary, a small amount of non-reactive organic solvent may be added. As the polymerizable monomer, any monomer having at least one ethylenically unsaturated bond capable of radical polymerization and capable of dissolving the oil-modified alkyd resin at a required concentration (details described later) can be used. However, since the resin composition of the present invention is intended to be cured at room temperature or by heating, its boiling point is 200°C.
Polymerizable monomers that are higher than above, for example,
Acrylates or methacrylates having a temperature of 200° C. or higher are particularly preferred. Specific examples of polymerizable monomers that can be used are as follows. These can be used together. (1) Relatively low boiling points: styrene, methyl methacrylate, divinylbenzene. (2) High boiling point seno(meth)acrylate There are monoacrylates and monomethacrylates of monohydric or polyhydric alcohols, preferably monohydric to dihydric alcohols, having 2 to 20 carbon atoms, preferably 2 to 18 carbon atoms. In this alcohol, the group to which the hydroxyl group is bonded does not necessarily have to be a hydrocarbon, and may have an ether bond, for example. Some specific examples of such monoacrylates and monomethacrylates are as follows. In the following, the expression "(meth)acrylate" means acrylate and methacrylate. 2-hydroxyethyl (meth)acrylate,
2-hydroxypropyl (meth)acrylate,
2-hydroxyethoxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, neopentyl glycol mono(meth)acrylate, 3-butoxy- 2-hydroxypropyl (meth)acrylate, 2-hydroxy-1 or 2-phenylethyl (meth)acrylate, polypropylene glycol monomethacrylate, glycerin mono(meth)acrylate monohalf maleate, diethylene glycol mono(meth)acrylate, cyclohexyl (meth)acrylate Acrylate, benzyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate. (3) High boiling point di- or tetra(meth)acrylate having at least two hydroxyl groups and having 2 to 20 carbon atoms;
Preferably there are di, tri or tetraesters of 2 to 6 alcohols, preferably dihydric to tetrahydric alcohols, with acrylic acid or methacrylic acid. In this alcohol, the group to which the hydroxyl group is bonded does not necessarily have to be a hydrocarbon, and may have, for example, an ether bond. In addition, in the case of trihydric or higher alcohol, at least two hydroxyl groups thereof need only be esterified with acrylic acid or methacrylic acid. Specific examples of such di-, tri-, and tetraacrylates and methacrylates are as follows. ethylene glycol di(meth)acrylate,
diethylene glycol di(meth)acrylate,
1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate
Acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, glycerin monoacrylate monomethacrylate. Particularly preferred polymerizable monomers as diluents include tetrahydrofurfuryl acrylate, 2-hydroxypropyl acrylate, and 3-butoxy-2-
These are hydroxypropyl acrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, and trimethylolpropane tri(meth)acrylate. Examples of non-reactive organic solvents include toluene, xylene, mineral spirits, methyl ethyl ketone, petroleum ether, and ethyl cellosolve. [Polymerization initiator] Examples of the polymerization initiator that initiates radical polymerization include methyl ethyl ketone peroxide, benzoyl peroxide, and cyclohexane peroxide. [Accelerator] In the present invention, the metal desiccant that is the accelerator is
At least three types are used in combination. Namely, (a) cobalt salts of organic carboxylic acids, (b) lead salts of organic carboxylic acids, and (c) organic carboxylates of metals selected from manganese, calcium, zirconium, and iron. The use of two or more types of metal desiccants in combination is described in Japanese Patent Publication No. 51-47726, which uses a zirconium compound having an alkoxy group and a cobalt carboxylic acid salt in combination to achieve internal drying properties and surface drying properties comparable to lead metal soaps. A technique for preparing a solvent-type oil-modified alkyd resin paint with excellent properties is described in U.S. Patent No. 2,739,902, which describes a paint with excellent air-drying properties using a combination of zirconium soap and cobalt soap or manganese soap. . However, even if both techniques are used, when an epoxy resin is used as an undercoat paint, lifting cannot be prevented in winter when an oil-modified alkyd resin topcoat paint is applied directly. In the present invention, metal soaps of the following components (a), (b), and (c) are used in combination in a specific ratio to provide a coating film that is excellent in air-drying properties and excellent in preventing lifting. (a) Cobalt salt of organic carboxylic acid
0.01 to 1 part by weight (metal content) (b) Lead salt of organic carboxylic acid
0.01 to 1 part by weight (metal content) (c) Organic carboxylate of a metal selected from manganese, calcium, zirconium, and iron
0.0001 to 1 part by weight (metal content). [The above blending amount is the blending ratio with respect to 100 parts by weight of the oil-modified alkyd resin. However, when the diluent is a polymerizable monomer, the proportion is based on 100 parts by weight of the oil-modified alkyd resin and the polymerizable monomer. ] The cobalt salt of the organic carboxylic acid as the component (a) greatly contributes to the surface drying properties of the coating film, and the lead salt of the organic carboxylic acid as the component (b) greatly contributes to the internal drying properties of the coating film. Also,
The organic carboxylate salt of component (c) works together with components (a) and (b) to contribute to prevention of lifting. However, depending on the type of amino curing agent in the epoxy resin in the undercoat, it may differ from the cobalt soap in (a).
Lifting can sometimes be prevented even in the coldest season by using lead soap (b) in combination, but metallic soap (c) is also used in combination to improve the lifting prevention effect. Component (c), manganese, calcium, iron, or zirconium metal soap, is inferior to the above-mentioned cobalt soap and lead soap in terms of drying properties. In particular, when calcium soap is used alone, it has poor room-drying properties. Further, when cobalt soap and manganese soap are used alone, the color difference is larger than that of a coating film obtained from a composition that does not contain these metal soaps. Note that even if component (c) calcium soap, manganese soap, iron soap, or zirconium soap is used in combination with cobalt soap (a) or lead soap (b), the effect of preventing lifting is small. Among these components (c), organic carboxylates of calcium are the most effective for internal curing of paints, so the order of metal reduction potential, namely Ca, Ca,
It is presumed that Mn, Zr, Fe, Pb, and Co have the effect of suppressing the reaction between the amine curing agent and the polymerization initiator in that order. However, since the top coat cannot be applied unless the surface of the paint film is dry, it is assumed that the combination of metal soaps (a) and (b) is also essential. These metal soaps (a), (b), and (c) are naphthenic acid,
It is obtained by reacting a monocarboxylic acid such as octenoic acid, isononanoic acid, 2-ethylhexanoic acid, cycloheptanoic acid, or 2,2-dimethyloctanoic acid with the desired metal in a solvent such as alcohol or acetone. In addition to (a), (b), and (c), iron soaps and rare earth (lanthanide, cerium, etc.) soaps may be used in combination with these metal soaps. Particularly preferred combinations of metal soaps are as follows (amounts relative to 100 parts by weight of oil-modified alkyd resin). Cobalt salt of organic carboxylic acid
0.01-0.1 parts by weight (metal content) Lead salt of organic carboxylic acid
0.01-0.1 parts by weight (metal content) Manganese salt of organic carboxylic acid
0.005-0.5 parts by weight (metal content) Calcium salt of organic carboxylic acid
0.01 to 1 part by weight (metal content) Zirconium salt of organic carboxylic acid
0.0003-0.003 parts by weight (metal content) Iron salt of organic carboxylate
0 to 0.001 parts by weight (metal content). These metal soaps are usually used after being dissolved in alcohol, acetone, mineral spirits, etc. [Composition] The oil-modified alkyd resin composition used in the present invention is (A) 30-70% by weight of oil-modified alkyd resin (B) 70-30% by weight of a diluent that dissolves the above component (A) (C) Polymerization initiation Agent 0.01 to 5% by weight of the sum of components (A) and (B) above (D) Accelerator containing the metal soaps of (a), (b), and (c) 0.3 parts by weight per 100 parts by weight of alkyd resin ~3 parts by weight. Component (A) accounts for 30 to 70% by weight, preferably 40 to 60% by weight of the total amount of components in the oil-modified alkyd resin composition. If it exceeds 70%, the resin composition becomes extremely viscous, making it difficult to prepare or use it, such as coating it. On the other hand, if it is less than 30%, when a polymerizable monomer is used as component (B), the corrosion resistance, impact resistance, or bending resistance of the resulting coating film will decrease. Component (B) is 70-30% by weight, preferably 60-40%
occupies When using a polymerizable monomer as component (B), the component
Among (B), the amount of di-, tri-, or tetra(meth)acrylate is preferably large in order to obtain a highly hard coating film with excellent corrosion resistance and acid-alkali resistance. However, in that case, there is a tendency for the flex resistance and impact resistance of the coating film to decrease. Therefore, the content of di- or tetra(meth)acrylate is determined depending on its intended use. The amount of the polymerization initiator as component (C) is the amount that is usually added to oil-modified alkyd resin paints. Component (D), the accelerator, is also used in the normally used amount or slightly more. The amounts of these components (C) and (D) are determined by the drying properties of the paint,
Determine by taking into account lifting prevention properties. In addition to these components (A), (B), (C), and (D), pigments such as titanium oxide, ultramarine, and red, viscosity modifiers such as silicone oil, methyl cellulose, and polyvinyl alcohol, antifoaming agents, etc. May be blended. [Undercoat paint] The undercoat paint applied to the base material is an epoxy resin paint containing an amino hardening agent. Examples of epoxy resins include the following. As bisphenol type epoxy resins, commercially available products such as Epicote 828, Epicote 834, Epicote 836, Epicote 1001, Epicote 1004, manufactured by Yuka Ciel Epoxy Co., Ltd.
1007; Trade name: Araldite manufactured by Ciba Geigy Co., Ltd.
GY252, GY250, GY260, GY280,
6071, 6084, 6097; trade names DER330, 331, 337, 661, 664, manufactured by Dow Chemical; trade names Epicron 800, manufactured by Dainippon Ink and Chemicals;
1010, 1000, 3010; Examples of phenol novolak type epoxy resins include DEN431, 438, 439 manufactured by Dow Chemical Co., Ltd.; Ciba Geigy
Product name: EPN1138 manufactured by Dainippon Ink and Chemicals Co., Ltd.
Epiklon N-565 and N-577 manufactured by Ciba Geigy Co., Ltd.; products such as Araldite CT-508 manufactured by Ciba Geigy; DER732 and DER732 manufactured by Dow Chemical Co., Ltd. 736, same
741; As an ester type epoxy resin, for example, the trade name Epicron 200 manufactured by Dainippon Ink and Chemicals Co., Ltd.
400, 1400; epoxidized polybutadiene manufactured by Nippon Soda Co., Ltd. under the trade name BF-1000; epoxidized oil manufactured by Adeka Argus Chemical Co. under the trade names ADEKA Sizer O-180 and ADEKA O-130P ; and so on. Furthermore, it should be noted that epoxy compounds and derivatives of the above-mentioned epoxy resins that can be easily inferred from these compositions are also included within the scope of the present invention. Examples include polyol-type epoxy resins, alicyclic epoxy resins, halogen-containing epoxy resins, silicon-modified epoxy resins, and the like. The above-mentioned epoxy resins are either liquid or solid at room temperature, and both can be used satisfactorily by adding a solvent that can dissolve them. Furthermore, there is no problem in using an epoxy resin that is liquid at room temperature and an epoxy resin that is solid at room temperature. Furthermore, in the present invention, a monoepoxy compound having one epoxy group in the molecule can be used in combination, if necessary, in order to improve the workability, coating performance, and coating condition of the epoxy resin. Examples of the monoepoxy compound include allyl glycidyl ether, 2-ethylhexyl glycidyl ether, methyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, styrene oxide, cyclohexene oxide, epichlorohydrin, or those having two or more epoxy groups in the molecule. Examples include compounds having one epoxy group obtained by modifying an epoxy resin with a fatty acid or the like. Furthermore, preferably 20
It is possible to use other resins in a weight percent or less.
The resin used in particular is the epoxy group in the epoxy resin,
Although it is not necessary to react with the amino groups in the curing agent described below, it can be added and used in combination to improve the coating workability of the composition, the coating film performance, the surface condition of the coating film, etc. For example, amino resin, phenolic resin, alkyd resin, polyester resin, urethanized oil,
Examples include coal tar, asphalt, xylene resin, polyvinyl formal, and polyvinyl acetal. On the other hand, examples of the amino curing agent include amino compounds such as amine adduct resins, polyamide resins, and polyamines, which are usually used as curing agents for epoxy resins. The polyamide resin is a condensation of dimer acid (general industrial products contain about 3% monomer acid, about 85% dimer acid, and about 12% trimer acid) and polyamines such as ethylenediamine, diethylenetriamine, or metaphenylenediamine. It is a product. For example, commonly available commercially available Fuji Kasei Kogyo Co., Ltd. product names Tomide Y-25, Tomide 210, Tomide 215,
Same 215-X, Same 225, Same 225-X, Same 235S, Same
235A, 245, 2400, 2500; Daiichi General Co., Ltd.
Product name: Zenamide 2000, Versamide 115, Versamide 125,
Same 100, Same 140, Same 230, Same 280, Same 400, Same 401, Same
415, DSX-1280; trade names Sanmide 320 and 330, manufactured by Sanwa Kagaku Co., Ltd.; and Epicure 4255, manufactured by Ciel Chemical Co., Ltd., and the like. The amine adduct resin is an addition product of the above-mentioned epoxy resin such as a bisphenol type epoxy resin and a polyamine such as ethylenediamine, diethylenetriamine or metaphenylenediamine. For example, commonly available products such as Tomide 238, Fujikiure 202, and 110 manufactured by Fuji Kasei Kogyo Co., Ltd. and ADEKA Hardener EH-531, 101, 532, and 551 manufactured by Asahi Denka Co., Ltd. are commonly available. . Furthermore, the amine adducts include addition products of butyl glycidyl ether, glycidyl ester of versatate acid, bisphenol type epoxy resins, etc., and heterocyclic diamines represented by the following formula, for example. For example, Epomate B-002, Epomate B-001, Epomate C-002, manufactured by Ajinomoto Co., Inc., which are generally commercially available;
Same S005, Same S002, Same LX-1, Same RX-2, Same RX
-3, N-001; These curing agents may be used alone or as a mixture of two or more depending on the purpose. The curing agent needs to have at least two or more nitrogen atoms and an active hydrogen bonded to the nitrogen atoms in one molecule in order to perform a crosslinking reaction with the epoxy resin. The curing agent is not particularly limited, but preferably has an amine value of 50 or more. However, if the amine value of the curing agent becomes extremely high, there will be a restriction that the pot life after mixing with the epoxy resin as the main ingredient will be shortened. [Painting method] For painting, the above-mentioned epoxy resin undercoat paint is applied on the base material of plants, ships, bridges, etc., and after drying, oil-modified alkyd resin paint is applied in 2 to 5 times. Repeat drying to obtain a coating of desired thickness. Painting is performed by brushing, air spray painting, airless painting, etc. so that the dry coating film has a thickness of 30 to 500 microns. On top of this oil-modified alkyd resin coating, another paint such as polyester paint, alkyd paint, etc.
A vinyl chloride paint may be further applied. The present invention will be explained below with reference to Examples. All "parts" in the following Examples and Comparative Examples mean parts by weight. [Production of oil-modified alkyd resin] Production example 1 Dehydrated castor oil fatty acids were placed in a reactor equipped with a stirrer, thermometer, cooler, water separator, and nitrogen inlet pipe.
62.0 parts, 12.6 parts of phthalic anhydride, 9.9 parts of MBTHP, 1.5 parts of glycerin, and 17.8 parts of pentaerythritol, and a hydroquinone component concentration of 3.0%.
An oil-modified alkyd resin (resin-A) with an oil length of 64.8% was obtained. Production example 2 Dehydrated castor oil fatty acid 53.4 parts, phthalic anhydride 13.5 parts
part, MBTHP 10.7 parts, pentaerythritol 21.7 parts
part, and 10.7 parts of sorbic acid to determine the final acid value.
The reaction was carried out in exactly the same manner as in Production Example-1 except that 35 was used to obtain an oil-modified alkyd resin (Resin-B) having a sorbic acid component concentration of 10.7% and an oil length of 55.8%. Production example 3 Soybean oil fatty acid 52.9 parts, phthalic anhydride 14.9 parts,
The reaction was carried out in exactly the same manner as in Production Example-1 except that 11.7 parts of MBTHP, 5.5 parts of glycerin, 15.1 parts of pentaerythritol, and 7.1 parts of sorbic acid were used.
An oil-modified alkyd resin (Resin-C) with a sorbic acid component concentration of 7.1% and an oil length of 55.3% was obtained. Production example 4 Dehydrated castor oil fatty acid 56.5 parts, phthalic anhydride 15.0 parts
11.9 parts of MBTHP, 6.7 parts of glycerin, 13.5 parts of pentaerythritol, and 3.5 parts of crotonic acid, but reacted in exactly the same manner as in Production Example-1 to obtain a modified oil with a crotonic acid component concentration of 3.5% and an oil length of 59.0%. Sho alkyd resin (resin-D) was obtained. Production example 5 Dehydrated castor oil fatty acid 54.6 parts, phthalic anhydride 15.1 parts
part, MBTHP 12.0 parts, glycerin 7.7 parts, pentaerythritol 12.1 parts and 2-(β-furyl)
The reaction was carried out in exactly the same manner as in Production Example-1 except that 5.4 parts of acrylic acid was used to obtain an oil-modified alkyd resin (Resin-E) with a 2-(β-furyl)acrylic acid component concentration of 5.4% and an oil length of 57.1%. . Production Example 6 Dehydrated castor oil fatty acids were placed in a reactor equipped with a stirrer, thermometer, cooler, water separator, and nitric acid inlet tube.
After adding 60.0 parts of phthalic anhydride, 26.9 parts of phthalic anhydride, 14.8 parts of glycerin, and 5.4 parts of pentaerythritol, and further adding 4 parts of xylene, the mixture was heated at 220°C in a nitrogen stream.
The reaction was continued until the acid value reached 20 or less. Water, xylene, etc. were removed to obtain a yellow-brown dehydrated castor oil fatty acid-modified alkyd resin (resin-F) with an oil length of 62.8%. Preparation of epoxy resin undercoat paint Undercoat A Bisphenol type epoxy resin [Product name: Epicoat 1001, manufactured by Yuka Ciel Epoxy Co., Ltd., epoxy equivalent
450-500] was dissolved in 100 parts of ethylene glycol monobutyl ether to obtain a resin solution whose nonvolatile content was adjusted to 50%. To the above resin solution, 50 parts of red iron, 100 parts of talc,
50 parts of precipitated barium sulfate and 100 parts of ethylene glycol monobutyl ether were added and kneaded with a roller to obtain a main ingredient. On the other hand, a polyamide resin (trade name: Tomide 225, manufactured by Fuji Kasei Kogyo Co., Ltd., amine value: 300±20) was dissolved in ethylene glycol monobutyl ether and the nonvolatile content was adjusted to 50% to prepare a curing agent. The mixing ratio of main agent/curing agent is 100/15 (weight ratio). The base paint B was the same as the base paint A. On the other hand, a polyamide resin (trade name Versamide 115, manufactured by Daiichi Vineral Co., Ltd., amine value 230-246) was dissolved in ethylene glycol monobutyl ether and the nonvolatile content was adjusted to 50% to prepare a curing agent. The mixing ratio of main agent/curing agent is 100/20 (weight ratio). The base paint C was the same as the base paint A. On the other hand, amine adduct resin [trade name Fujikure 202 manufactured by Fuji Kasei Kogyo Co., Ltd., active hydrogen equivalent 120] 30
A curing agent was prepared by dissolving 70 parts of a polyamide resin (trade name Tomide 225, manufactured by Fuji Kasei Kogyo Co., Ltd., amine value 300±20) in ethylene glycol monobutyl ether and adjusting the nonvolatile content to 50%. The mixing ratio of main agent/curing agent is 100/15 (weight ratio). Preparation of resin composition and performance evaluation as paint] Examples 1 to 5, Comparative Examples 1 to 13 Oil-modified alkyd resin obtained in Production Example 1 - A55
part was dissolved in a polymerizable monomer mixture of 10 parts of hydroxypropyl methacrylate and 35 parts of 1,4-butanediol diacrylate. Cobalt naphthenate (cobalt content 6%), manganese naphthenate (manganese content 5%), lead naphthenate (lead content 15%), calcium naphthenate (calcium content 3%), iron naphthenate (iron content 5%),
Zirconium naphthenate (zirconium content 4
%) and cyclohexanone peroxide to prepare an oil-modified alkyd resin top coat. Primer paint A was applied to a polished mild steel plate (50 mm x 150 mm, wall thickness 0.3 mm, polished with #320 polishing cloth) to obtain a 50 micron film, and then dried in an air bath at 5°C for 2 days. . The top coat shown in Table 1 was applied onto the obtained undercoat film using an applicator so that a first top coat film with a film thickness of 50 microns was obtained, and was dried to the touch in a low temperature dryer at 5°C. The time was measured. The results are shown in the same table. On the other hand, a top coat with the same composition as shown in Table 1 was applied on top of a 50 micron film obtained by applying a top coat and drying it at 5℃ for 2 days, and drying it at 5℃ for 2 days. The presence or absence of lifting of the second top coat film with a wall thickness of 50 microns was investigated. The results are shown in the same table.

【table】

[Table] * Metal content of metal soap

[Table] Example 6 The drying time to the touch, the gloss of the paint film, and the top coat paint prepared in the same manner as in Example 1 except that the undercoat paint was changed as shown in Table 2 using the metal soaps shown in the same table. The presence or absence of lifting was investigated. The results are shown in the same table. The abbreviations in the table are as follows. HPA: Hydroxypropyl methacrylate BDDA: 1,4-butanediol diacrylate Co: Cobalt naphthenate Mn: Manganese naphthenate Pb: Lead naphthenate Zr: Zirconium naphthenate Ca: Calcium naphthenate Mix: Same metal soap as in Example 1 blend

[Table] Example 7 In Example 1, the metal soap of the top coat was not changed, but the types and amounts of the oil-modified alkyd resin, polymerizable monomer, and polymerization initiator were changed as shown in Table 3. Painting was performed and evaluated in the same manner. The results are shown in the same table.

【table】

Claims (1)

[Scope of Claims] 1. After applying an epoxy resin undercoat containing an amino curing agent onto a substrate and drying it to form an undercoat film, the following metal desiccant mixture undergoes radical polymerization and oxidation. Per 100 parts by weight of a polymerizable room temperature curable solvent-free oil-modified alkyd resin coating composition.
A method for forming an anti-corrosion coating film, characterized in that a top coat compounded in a proportion of 0.3 to 3 parts by weight is applied onto the base coat film and dried to form a cured film Metal desiccant mixture: (a) Cobalt salt of organic carboxylic acid
0.01 to 1 part by weight (metal content) (b) Lead salt of organic carboxylic acid
0.01 to 1 part by weight (metal content) (c) Organic carboxylate of a metal selected from manganese, calcium, zirconium, and iron
0.0001 to 1 part by weight (metal content). 2. The oil-modified alkyd resin coating composition contains (A) 30 to 70% of the oil length modified with an α,β-unsaturated monocarboxylic acid selected from sorbic acid, crotonic acid, and 2-(β-furyl)acrylic acid. Oil-modified alkyd resin (however, α,β-unsaturated monocarboxylic acid content is 0.5 to 30% by weight)
30-70% by weight (B) Component Polymerizable monomer that dissolves the above (A)
70 to 30% by weight (C) Radical polymerization initiator Claim 1, characterized in that the radical polymerization initiator is blended in a proportion of 0.01 to 5% by weight of the sum of components (A) and (B). Method described.