JPH046726B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing an aqueous resin. (Prior Art) Since paints usually use large amounts of organic solvents, the organic solvents are emitted into the atmosphere during painting, causing air pollution and increasing the risk of fire. In recent years, various efforts have been made to reduce the amount of organic solvent volatilization, and high solids paints, powder paints, electron beam, ultraviolet curing paints, water-based paints, and the like have been developed for this purpose. In particular, water-based paints are attracting attention because they use water, which is non-hazardous and highly economical, and can be easily converted from conventional painting equipment. However, conventional water-based paints have drawbacks such as slow drying of the paint and poor water resistance and corrosion resistance. Various methods have been devised to overcome these drawbacks, including methods of incorporating phenolic resins, petroleum resins, epoxy resins, etc. into the resin component of water-based alkyd resin paints, methods of incorporating polymerizable monomers, etc. Examples include a method of polymerizing. One of these is as described in Japanese Patent Publication No. 49-5884 or Japanese Patent Application Laid-open No. 54-30249,
Water-dilutable vinyl-modified resins based on bisphenol-type epoxy resins and fatty acid esters are known. (Problems to be Solved by the Invention) However, although the water-dilutable vinyl modified resin described in the above publication has good corrosion resistance and water resistance,
Poor paint stability and tends to separate into two layers during storage. (Means for Solving the Problems) The present invention comprises (a) 25 to 60 parts by weight of a fatty acid, (b) 70 to 20 parts by weight of a bisphenol type epoxy resin, and (c) 1 to 4 glycidyl groups in one molecule. Fatty acid ester obtained by adding and condensing 2 to 40 parts by weight of an aliphatic epoxy compound having 10 to 90 parts by weight
% by weight of a polymerizable vinyl monomer containing a carboxyl group-containing polymerizable vinyl monomer as an essential component. The fatty acids that are component (a) used in the present invention include fatty acids that can be derived from drying oils or semi-drying oils and synthetic fatty acids, such as tung oil, soybean oil, linseed oil, castor oil, dehydrated castor oil, and safflower oil. Examples include fatty acids obtained from oil, cottonseed oil, etc., and synthetically obtained versatic acid (trade name of Shell Chemical Co., Ltd.). As component (a), it is preferable to use a fatty acid that can be derived from a drying oil or a semi-drying oil because it can impart room-temperature curability, but fatty acids that can be derived from a non-drying oil may also be used. (a) Components may be used alone or in combination. If the amount of component (a) used is too small, the flexibility of the coating film tends to decrease, and if the amount of component (a) used is too small, the hardness and corrosion resistance of the coating film tend to decrease. The bisphenol type epoxy resin, which is the component (b), is an epoxy resin obtained by the reaction of bisphenols such as bisphenol A and bisphenol F with epichlorohydrin, such as Epicote 828, Epicote 1001, Epicote 1004, Commercially available products such as Epicote 1007 and Epicote 1009 (both trade names of Ciel Chemical Co., Ltd.) can be used. One or more types of component (b) may be used, but those having a softening point of 60° C. or higher are particularly preferred from the viewpoint of coating film performance. If the amount of component (b) used is too small, the hardness and corrosion resistance of the coating film will tend to decrease.
If the amount is too large, the flexibility of the coating film tends to decrease. The aliphatic epoxy compounds having 1 to 4 glycidyl groups in one molecule as component (c) include glycidyl ethers of monohydric aliphatic alcohols such as lauryl alcohol and allyl alcohol, ethylene glycol, propylene glycol, butylene Diglycidyl ethers of alkylene glycols such as glycols, dihydric aliphatic alcohols such as diethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, tetramethylene glycol, poly(tetramethylene glycol), 1,6-hexanediol, neopentyl glycol, etc. , trimethylolpropane, glycerin, etc.
or di-, tri- or tetra-glycidyl ethers of tetravalent or higher aliphatic alcohols such as tri-diglycidyl ether, pentaerythritol, sorbitol, glycerin dimer, glycerin polymer, etc., adipic acid, tetramethylene dicarboxylic acid, etc. Examples include diglycidyl esters of aliphatic dicarboxylic acids. (c) Components may be used alone or in combination. If the amount of component (c) used is too small, the hardness of the coating film will decrease, and if it is too large, the stability of the paint will tend to decrease. The fatty acid ester includes component (a), component (b), and (c)
It is obtained by reacting the components, and the reaction method is an addition or condensation reaction using a known method. For example, it may be heated at 180 to 250°C. This reaction may be carried out in an organic solvent such as xylene or toluene that does not react with components (a), (b) and (c). In addition, the reaction may be carried out by simultaneously mixing and reacting component (a), component (b), and component (c), and component (a) and component (b) or
After reacting component (c), component (c) or component (b) may be added and reacted. The product will be a mixture of esters of components (a) and (b) and esters of components (a) and (b), but if these esters are manufactured separately and used as a mixture, the characteristics will change. tends to decrease. Regarding the polymerizable vinyl monomers used in the present invention, those containing carboxyl groups include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, etc. Examples of the polymer include acrylic acid esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, tert-butyl acrylate, isobutyl acrylate, and 2-ethylhexyl acrylate; Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate,
Methacrylic acid esters such as tert-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, styrene, vinyltoluene,
Other examples include styrenic monomers such as α-methylstyrene, vinyl acetate, β-hydroxyethyl acrylate, glycidyl acrylate, glycidyl methacrylate, acrylamide, N,N-diethylmethacrylamide, acrylonitrile, methacrylonitrile, etc. One or more types of these can be used. A carboxyl group-containing polymerizable vinyl monomer is blended into the polymerizable vinyl monomer as an essential component. As a result, carboxyl groups are sufficiently introduced into the resin obtained by the present invention, making it possible to make it water-based. It is preferable that the carboxyl group-containing polymerizable vinyl monomer is adjusted and blended so that the acid value of the resin obtained by the present invention is 20 to 60. When using a polymerizable vinyl monomer having a functional group other than a double bond such as a hydroxyl group in addition to the carboxyl group-containing polymerizable vinyl monomer, this should be used in an amount of 70% by weight or less based on the fatty acid ester. It is preferable to do so. If it is too large, the water resistance of the coating film tends to decrease. The polymerizable vinyl monomer is polymerized in the presence of the fatty acid ester. In this case, the weight ratio of fatty acid ester/polymerizable vinyl monomer is 10/90 to 90/
10, preferably in a ratio of 50/50 to 80/20. If this weight ratio is too small, the water dilutability will be poor, and if it is too large, the drying properties of the coating film will tend to decrease. The polymerization of the polymerizable vinyl monomer can be carried out in the presence of the above fatty acid ester using a radical initiator in an organic solvent, preferably at 80 to 140°C. The organic solvent is preferably a hydrophilic solvent, such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, tert-butyl cellosolve, isopropyl cellosolve, isopropyl alcohol, butyl alcohol, tert-butyl alcohol, isobutyl alcohol, etc. can be used. The acid value of the resin after polymerization of the vinyl monomer is preferably adjusted to be in the range of 20 to 60. If the acid value is less than 20, paint stability tends to be poor;
When the acid value exceeds 60, the water resistance and alkali resistance of the coating film tend to be poor. The acid value can be adjusted by adjusting the amount of the carboxyl group-containing polymerizable monomer used. As the radical polymerization initiator, azobisnitrile type catalysts such as azobisisobutyronitrile and azobisvaleronitrile, benzoyl peroxide,
Peroxides such as butyl perbenzoate are used. After neutralization, the resin thus obtained can be used by dissolving or dispersing it in the above-mentioned mixed solvent of the hydrophilic solvent and water or in water (diluting with water). Neutralization and water dilution can be carried out by continuing to neutralize and further adding water after the polymerization is completed when the above polymerization is carried out in a hydrophilic solvent. After dissolving, it can also be neutralized and diluted with water. The above neutralization is carried out by neutralizing some or all of the carboxyl groups in the resin with a neutralizing agent so that the pH is preferably 7 to 10. As a neutralizing agent, amines such as ammonia, triethylamine, dimethylethanolamine, sodium hydroxide,
Alkali metal hydroxides such as potassium hydroxide, alkali metal carbonates such as sodium carbonate, bicarbonates such as sodium bicarbonate, and the like can be used. The aqueous resin obtained in this way can be used as it is after being diluted with water, but pigments, plasticizers, solvents, colorants, etc. may be added to it, or modified amino resins, epoxy resins, polyester resins, acrylic resins, etc. A wide variety of water-soluble or water-dispersible resins can also be incorporated. For example, modified amino resin,
By combining with epoxy resin etc., it can be used as a baking paint.In particular, among the aqueous resins obtained by the present invention, when a drying oil or semi-drying oil fatty acid is used, a metal drying agent is added. It is useful as a room-temperature curing paint.
These can be made into paints by further using commonly used pigments, surface treatment agents, organic solvents, etc. The paint composition can be applied by dipping, brushing, spraying, roll coating, etc., and can be applied to surfaces such as wood, paper, fiber, plastic, ceramic, iron, and non-ferrous metals. . (Example) Next, the present invention will be explained in detail based on an example.
The present invention is not limited to this. Example 1 (A) In a glass flask equipped with a stirrer, a thermometer, a reflux dehydrator, and a nitrogen gas inlet tube, 10 g of xylene, 300 g of soybean oil fatty acid, and a bisphenol type epoxy resin (Epicote 1001, manufactured by Ciel Chemical Co., Ltd. After reacting at 230°C for 2 hours while blowing nitrogen gas, the mixture was cooled and a mixture of diglycidyl ether of trimethylolpropane and triglycidyl ether of trimethylolpropane ("Denacol EX321", Nagase Co., Ltd.) was added as an epoxy compound. Add 40g of Kasei Kogyo Co., Ltd. (trade name) and heat to 220°C while refluxing to proceed with addition and condensation until the acid value becomes 1 or less. After this, xylene is distilled off to obtain a fatty acid ester. . (B) Place (A) in a glass flask equipped with a stirrer, a thermometer, a reflux dehydrator, and a nitrogen gas inlet tube.
Add 252 g of the fatty acid ester obtained above and 193 g of butyl cellosolve and heat to 100°C with stirring.
66g styrene, 22g butyl acrylate, 20g methacrylic acid and 9g azobisisobutyronitrile
g was uniformly added dropwise over 2 hours and kept warm for an additional 3 hours. After cooling to 80℃, 23g of triethylamine
Add and stir. Add 280g of water and heat the remaining
A water-based paint with a viscosity of 42.5%, a viscosity of 96 Boas (25), and a pH of 8.9 was obtained. Example 2 In (A) of Example 1, 180 g of bisphenol type epoxy resin ("Epicote 1001", trade name of Ciel Chemical Co., Ltd.) and an epoxy compound ("Denacol
EX321, manufactured by Nagase Chemical Industries, Ltd.) was used in the same manner as in Example 1, and the heating residue was 43.4 g.
%, a viscosity of 101 poise (25°C), and a pH of 9.0. Example 3 In (A) of Example 1, 240 g of soybean oil fatty acid,
Bisphenol type epoxy resin ("Epicote")
1001'', manufactured by Ciel Chemical) 240g, epoxy compound (``Denacol EX321'', manufactured by Nagase Chemical Industries, Ltd.)
The procedure was the same as in Example 1 except that 120 g was used, and the heating residue was 39.8%, the viscosity was 95 poise (25°C), and the pH was
A water-based paint of 8.9 was obtained. Comparative Example 1 (A) 300 g of soybean oil fatty acid and 300 g of Epicote 1001 (manufactured by Ciel Chemical) were placed in a glass flask equipped with a stirrer, thermometer, reflux dehydrator, and nitrogen gas inlet tube, and nitrogen gas was introduced into the flask. 4 while refluxing xylene at 230℃ while blowing.
The reaction was carried out for several hours to obtain a fatty acid ester with an acid value of 10. (B) The same procedure as in Example 1 (B) was used except that 252 g of the fatty acid ester obtained in (A) was used. A water-based paint was obtained. Comparative Example 2 In (A) of Comparative Example 1, 240g of soybean oil fatty acid
and Epicote 1001 (manufactured by Ciel Chemical Co., Ltd.) at 360
A water-based paint having a heating residue of 41.4%, a viscosity of 100 poise (25° C.), and a pH of 9.1 was obtained by operating in the same manner as in Comparative Example 1, except that g was used. The aqueous resin liquids obtained in each of the Examples and Comparative Examples were made into paints as described below and tested. White enamel paint formulation: Titanium white (rutile type) 45g Precipitated barium sulfate 25g Butyl cellosolve 10g Water 10g Aqueous resin liquid of Example or Comparative Example 120g Antifoaming agent (Nopco 8034, San Nopco product name)
0.1g of the above components were dispersed in the presence of glass beads using a sand grinder at 1250 rpm for 60 minutes, and after removing the glass beads to obtain white enamel (),
A white enamel () was obtained by adding the following composition. 〓Aqueous resin liquid of the same example or comparative example above
150 g 6% cobalt naphthenate 0.7 g 12% zirconium naphthenate 0.7 g The white enamel thus obtained () was diluted with an appropriate amount of water and prepared in a #4 food cup for 30-35 seconds. Table 1 shows the stability and film characteristics test results of this paint. Test plate creation conditions Base material: Bonderite #1077 treated steel plate (Japan Test Panel Co., Ltd., thickness 0.8 mm) Painting: Air spray (Iwata Wyda 61, caliber 1.5)
mm), air pressure 4Kg/cm ² Drying: 3 days at 22-24℃.

[Table] (Effects of the Invention) According to the present invention, it is possible to produce a resin for water-based paints that has excellent paint stability and good coating film properties.

Claims (1)

[Claims] 1 (a) Fatty acid 25 to 60 parts by weight (b) Bisphenol type epoxy resin 70 to 20 parts by weight (c) Aliphatic epoxy compound having 1 to 4 glycidyl groups in one molecule Fatty acid ester 10-90 obtained by adding and condensing 2-40 parts by weight
A method for producing an aqueous resin, which comprises polymerizing 90 to 10% by weight of a polymerizable vinyl monomer containing a carboxyl group-containing polymerizable vinyl monomer as an essential component in the presence of 90% to 10% by weight. 2 The polymerizable vinyl monomer is blended with a carboxyl group-containing vinyl monomer as an essential component so that the resulting aqueous resin has an acid value of 20 to 60. Method for producing water-based resin.