JPS6146504B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an improved composition of a vinyl polymer emulsion obtained by radical polymerization of an unsaturated vinyl monomer using an oxidation-curing polymeric water-soluble resin as an emulsion stabilizer. More specifically, the present invention relates to an aqueous coating-forming composition that has been improved so that a hard and tough coating film can be obtained by impregnating the emulsion with an esterified product of a drying oil fatty acid or a semi-drying oil fatty acid. The present inventors have conducted various studies on emulsions using polymeric oxidation-curable water-soluble resins as emulsion stabilizers. These emulsions have characteristics not found in ordinary emulsions due to oxidative curing, but when actually used as resins for low-pollution coatings, they have a sufficient minimum film-forming temperature. The drawback was that it was not possible to achieve both low hardness and sufficient coating hardness. The present invention was completed as a result of intensive research into solving the above-mentioned drawbacks. That is, the present invention provides a maleated polydiene,
An emulsion obtained by radical polymerization of an unsaturated vinyl monomer using at least one polymeric oxidation-curable water-soluble resin selected from maleated alkyd and maleated fatty acid modified styrene-allyl alcohol copolymer resin as an emulsion stabilizer. After solubilizing an oily ester of relatively low molecular weight drying oil fatty acid or semi-drying oil fatty acid and glycidyl acrylate or glycidyl methacrylate (hereinafter simply referred to as "oil-based compound") with a fatty acid-modified water-soluble acrylic resin, The present invention relates to an aqueous coating-forming composition that can lower the minimum film-forming temperature and obtain sufficient hardness by mixing 0.1 to 150 PHR with respect to the solid content of the emulsion. The vinyl polymer emulsion used in the present invention must be an emulsion containing a high molecular weight oxidation-curable water-soluble resin as an emulsifier. Emulsions that use such emulsifiers as dispersion stabilizers have a high molecular weight, and a graft reaction occurs during emulsion polymerization, which further polymerizes and binds strongly to the emulsion surface. Can withstand shock when impregnated with Furthermore, during curing, since there is already a high-molecular oxidation-curable resin, the gel effect accelerates the curing of the oil-based compound, and the gel network easily spreads over the entire surface, creating a strong coating film. is obtained. Examples of the polymeric oxidation-curable water-soluble resins that can be used in the present invention include maleated polydienes, maleated alkyds, maleated fatty acid-modified styrene-allyl alcohol copolymer resins, maleated fatty acid-modified epoxy resins, maleated oils, and maleated fatty acid-modified epoxy resins. Emulsion itself is easier to form when the structure of the part that comes into contact with water is oily, such as stand oil, maleated boiled oil, maleated fatty acid-modified acrylic resin, fatty acid-modified acrylic resin, etc. It is preferred because it is suitable for impregnation. Other usable water-soluble resins include water-soluble alkyd resins and oil-modified water-soluble epoxy resins. The number average molecular weight of these water-soluble resins is 500~
50,000, preferably in the range of 800 to 15,000, and the acid value is in the range of 20 to 350, preferably 50 to 200. The maleated polydiene has 4 to 8 carbon atoms.
Polymers of diene compounds and copolymers thereof are maleated by conventional methods. Maleated polybutadiene and copolymers thereof are preferred, and those containing 20% or more of a 1,2-vinyl structure are particularly preferred because they are easy to graft during polymerization, stable, and have good weather resistance. In resins such as maleated alkyd resins, maleated fatty acid-modified epoxy resins, and maleated fatty acid-modified acrylic resins, the fatty acid groups are dry oil fatty acids or semi-dry fatty acids due to the necessity of maleation and oxidative curing. The oil length needs to be 20 or more, preferably 40 or more. Among maleated oils, maleated stand oils, and maleated boiled oils, stand oils and boiled oils with high molecular weights are preferred. Fatty acid-modified water-soluble acrylic resin is made by copolymerizing acid monomers such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, hydrous acid group-containing monomers, or epoxy group-containing monomers, and other general monomers.
It is a polymer that is ultimately in the form of a drying oil or semi-drying oil with fatty acids bound to it. In this case, in order to produce oxidative hardening and good emulsion, the oil length should be 5 or more, preferably
Must be 20 or more. The above resins may be modified by epoxidation, esterification, amidation, grafting, etc. if necessary.
It may be modified with isocyanate, melamine, urea, etc. These resins are preferably neutralized with volatile amines, ammonia, etc. and, if necessary, made water-soluble with the aid of water-soluble organic solvents. An emulsion of a vinyl polymer is obtained by radically polymerizing an unsaturated vinyl monomer in the above aqueous solution. The preferred unsaturated vinyl monomer used is one that is not strongly hydrophilic and generates a relatively inactive radical with a Q value of 0.1 or more in Qe theory. If the hydrophilicity is too strong, emulsion synthesis becomes difficult and at the same time impregnation of oily compounds is hindered.
On the other hand, if the radical activity is too strong, it will react with the oxidative reactive group of the water-soluble resin for dispersion stabilizer, causing the oxidative curing surface activity to be lost and at the same time, polymerization will be inhibited. Examples of preferred monomers include styrene, α-methylstyrene, vinyltoluene, esters of acrylic acid and methacrylic acid with alcohols having 1 to 26 carbon atoms, and condensates of glycidyl acrylate and glycidyl methacrylate with carboxylic acids having 1 to 26 carbon atoms. , methoxybutyl acrylate, methoxybutyl methacrylate, methoxyethyl acrylate, methoxyethyl methacrylate, ethoxybutyl acrylate, ethoxybutyl methacrylate, allyl acrylate, allyl methacrylate, butadiene, isoprene, chloroprene, and the like. These unsaturated vinyl monomers may be used alone or in combination of two or more. It can also be used in combination with the following monomers, but they must be contained in a total amount of 50% or more, preferably 70% or more. Monomers that can be used in combination with the above unsaturated vinyl monomers include 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate,
-Hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, acrylonitrile, methacrylonitrile, acrylic acid, methacrylic acid,
These include glycidyl acrylate, glycidyl methacrylate, vinyl acetate, Beopa monomer (manufactured by Schiel Chemical Co., Ltd., trade name), N-n-butoxymethylacrylamide, acrylamide, vinylpyridine, and other general radically polymerizable monomers. Of course, it is also possible to use a mixture of two or more of these monomers. The overall Tg point of the monomers used is preferably 60° C. or lower because this facilitates the penetration of the oily compound. The amount of water-soluble resin used as a dispersion stabilizer is such that the acid value in the total solid content, including unsaturated vinyl monomers, is 3 to 3.
150, preferably 10 to 50. The oily compound used in combination with the vinyl polymer emulsion is preferably one that has a low molecular weight, is easily impregnated, and hardens quickly. The oily compound that can be used in the present invention is an esterified product of a drying oil fatty acid or a semi-drying oil fatty acid. Fatty acids include tung oil, linseed oil, oiticica oil, poppy seed oil, eno oil, safflower oil, soybean oil, sesame oil, hempseed oil, grape kernel oil, corn oil, tall oil, sunflower oil, cottonseed oil, walnut oil, and rubber. These are fatty acids such as seed oil, fish oil, dehydrated castor oil, and high diene fatty acids. As a partner to be esterified, a saturated or unsaturated alcohol having 1 to 26 carbon atoms, an epoxy compound,
These include glycidyl acrylate and glycidyl methacrylate. In particular, glycidyl acrylate,
Adducts with glycidyl methacrylate are preferred because they cure quickly. The mixing ratio of the above low molecular weight oxidation-curing oil compound is 0.1 to 150 PHR based on the emulsion solid content.
It is. Preferably it is 30-50 PHR. The impregnation method can be carried out by stirring and mixing as is, but it is preferable to add after emulsifying or solubilizing with a water-soluble resin or a common emulsifier.
This is desirable as a method to avoid problems such as the occurrence of bumps. As the water-soluble resin, it is desirable to use an oxidation-curable water-soluble resin that is used as an emulsion stabilizer for the emulsion of the present invention. The emulsion according to the present invention has a high quality as a cold-curable coating resin, but of course it can also be cured by heating, and in this case, melamine or the like can also be added. In addition, it can be widely used in resin processing agents, adhesives, etc. Next, the present invention will be explained in detail with reference to examples, but the present invention is not limited to the examples. Reference row 1 Method for producing emulsion A 1,2-vinyl polybutadiene with a number average molecular weight of 3000 was maleated to obtain maleated polybutadiene with an acid value of 100. This is neutralized with 0.95 equivalents of ammonia, 35 PHR of butyl cellosolve is added and dissolved in water, 129 PHR of n-butyl methacrylate and 129 PHR of styrene are added and stirred well to form an emulsion. In addition, for monomer
Add 0.25PHR ammonium peroxide,
Heat to 80℃ and keep for 2 hours. In this way, a fine emulsion A with a solid content of 40% was obtained. Reference Example 2 Manufacturing method for emulsion B Add linseed oil fatty acids (RJ-101/linseed oil fatty acids = approx. 16/20) to all hydroxyl groups of RJ-101 (styrene-allyl alcohol copolymer manufactured by Monsanto, number average molecular weight 1150). After esterification, maleation was performed to obtain a resin with an oxidation rate of 100. A product neutralized in the same manner as in Reference Example 1 was used in place of the maleated polybutadiene in Reference Example 1, and the monomers were i-butyl methacrylate of 259 PHR and 1.6-hexanediol diacrylate corresponding to 2.4% of this. A fine emulsion B with a solids content of 40% was obtained using a mixture of the following. Reference Example 3 Production method of auxiliary water-soluble resin C that helps mix in oily compounds

[Table] The above monomer was polymerized dropwise into a butyl cellosolve solution to obtain a polymer with a peak molecular weight of about 7000 and an acid value of 80. In addition, as a dryer, 0.16 parts of Co (cobalt naphthenate), 0.16 parts of Mn (manganese naphthenate) and 0.45 parts of Pb (namali naphthenate)
was added to obtain auxiliary water-soluble resin C containing 25PHR butyl cellosolve neutralized with ammonia. Reference example 4 Manufacturing method of emulsion D 470 parts of isophthalic acid, 583 parts of pentaerythritol
A mixture of 599 parts of benzoic acid and 1644 parts of linseed oil fatty acid was heated to 240° C. in the presence of a dibutyltin oxide esterification catalyst, and the reaction was carried out for 6 hours until the resin acid number reached 1.3. Continue to adjust the temperature
Lower the temperature to 200℃, add 237 parts of maleic anhydride,
A maleation reaction was carried out at 200° C. for 3 hours to obtain a resin having a resin acid value of 62.6 and a Gardner viscosity (solid content: 60% butyl cellosolve solution) Y. Next, 42 parts of isopropyl alcohol and 16 parts of triethylamine were added to 140 parts of the resin, dissolved in water, and 132 parts of styrene and 1.6 parts of triethylamine were added.
- Add a mixture of 42 parts of hexanediol acrylate and stir well to form an emulsion. to this,
Add 23.2 parts of 4.7% ammonium persulfate aqueous solution,
Keep at 80℃ for 2 hours. In this way, 40% of the individual size
A fine emulsion D was obtained. Example 1 1 part (solid content, same below) of auxiliary water-soluble resin C
and 0.9 parts of a 1:1 adduct of linseed oil fatty acid and glycidyl methacrylate were mixed thoroughly, and then added to 9 parts of Emulsion A and mixed well. The performance test results of the obtained emulsion are shown in Table 1. Example 2 The amount of the linseed oil fatty acid and glycidyl methacrylate adduct of Example 1 was 1.8 parts. The performance test results are shown in Table 1. Example 3 The amount of the linseed oil fatty acid and glycidyl methacrylate adduct of Example 1 was 2.7 parts. The performance test results are shown in Table 1. Example 4 The amount of auxiliary water-soluble resin C in Example 1 was halved.
It was carried out as follows. The performance test results are shown in Table 1. Example 5 One part of auxiliary water-soluble resin C and a 1:1 adduct of safflower oil fatty acid and glycidyl methacrylate
Mix 1.8 parts well, then add to 9 parts of emulsion B and mix well. The performance test results are shown in Table 1. Example 6 Instead of the safflower oil fatty acid in Example 4, soybean oil fatty acid was used. The performance test results are shown in Table 1. Example 7 Instead of the 1:1 adduct of linseed oil fatty acid and glycidyl methacrylate in Example 1, iodine
A methyl ester of 180 fish oil fatty acids was used. The performance test results are shown in Table 1. Example 8 Emulsion D was used in place of Emulsion A in Example 1. The performance test results are shown in Table-1. Comparative Example 1 In Example 1, no oily compound was added. Comparative Example 2 No oily compound was added in Example 5. Comparative Example 3 No oily compound was added in Example 8.
The minimum film formation temperature was 30°C or higher, which resulted in poor results with cracking and peeling of the dried paint film.

【table】

〔Test items〕

For the pencil hardness, use a Mitsubishi Uni Pencil with a hardness code of 6B to 9H.
The hardness symbols for the lower grades are shown in the table. The gel fraction was calculated from the weight before and after extraction with tetrahydrofuran. For adhesion, use a knife to cut out 1 x 1 mm squares.
When 100 pieces are cut and cellophane adhesive tape is applied to these parts and quickly peeled off, the adhesiveness is expressed as n/100, where n is the number of remaining goblets. Impact resistance was measured using a DuPont impact tester using a 500 g weight with a diameter of 0.5 inches (20°C). Erichsen values were measured using an Erichsen tester (20°C). Water resistance was determined by immersing the film in water at 20°C for one day and observing whether or not there were any abnormalities in the paint film. Corrosion resistance is based on JIS Z 2371, and indicates the width of rust generated from the cut part after a one-day test.

Claims (1)

[Claims] 1 Radical polymerization of unsaturated vinyl monomers using at least one polymeric oxidation-curable water-soluble resin selected from maleated polydiene, maleated alkyd resin, and maleated fatty acid-modified styrene-allyl alcohol copolymer as an emulsion stabilizer. An oily ester of drying oil fatty acid or semi-drying oil fatty acid and glycidyl acrylate or glycidyl methacrylate is added to the emulsion obtained by
After solubilization with fatty acid-modified water-soluble acrylic resin, the solid content of the emulsion is 0.1~
An aqueous coating-forming composition prepared by mixing 150 PHR.