JPS58113268A - Water-dispersed coating - Google Patents

Abstract

PURPOSE:The titled coating causing no pollution that is made by adding water- insoluble coatings to a resin dispersion prepared by polymerizing vinyl monomers in a solution containing polyalkylene glycol and dispersing the resultant polymer in water, thus showing high storage stability and corrosion resistance and being used in can production. CONSTITUTION:The polymerization of a polymerizable vinyl monomer such as acrylic acid is conducted in a solution of (i) polyalkylene glycol in (ii) a water- soluble solvent such as methanol to form a polymer solution. The resultant resin solution is combined with water to prepare a resin dispersion and a water- insoluble powder coating is dispersed in the dispersion to give the objective coating. USE:Precoated metal, parts for cars and electric appliances for household.

Description

[Detailed Description of the Invention] The present invention! # Concerning water-dispersed paints that are useful as parent materials, E also relates to dispersion of powder paints in specific water-dispersed resins [containing stable materials]◇ Disperse it in a water-soluble 4IiJl11# liquid such as Furukito and use it as a water-dispersed paint. [When the used paint is stored for a month, the powder paint itself settles during storage, and the powder The paint has the disadvantage that it becomes swollen and tl-condensed by the bath agent contained in the system, resulting in a hard cake-like product that can no longer be used as a paint.

However, as a result of intensive research by the present inventors in view of the drawbacks of conventional dispersion coatings as described above, we discovered that, instead of such amine-neutralized type self-alkyd, polymerization was carried out in a solution containing a specific water-soluble compound. The stability of powder coatings relative to resin dispersions can be significantly improved only by using a water-dispersed Isi fat obtained by polymerizing polyvinyl mono-I and then adding water thereto. In addition, the present invention has been completed by discovering that the coating film made from the water-dispersed paint thus obtained has significantly improved corrosion resistance compared to conventional dispersion paints. A polymerizable vinyl monomer (hereinafter abbreviated as vinyl monomer) is polymerized in a solution of a water-soluble solvent in which polyalkylene glycol is dissolved (hereinafter also referred to as polyalkylene glycol solution) to form a single polymer resin. The object of the present invention is to provide a water-dispersed coating material, which comprises dispersing a water-insoluble powdery material in a resin dispersion obtained by adding water to the obtained solution.

Here, the above-mentioned IIji 马 dispersion liquid dispersion is obtained by combining vinyl monomers in a realkylene glycol bath liquid and then adding water, but as a more preferable embodiment, , 600~2G, 00
100 parts by weight of a vinyl monomer is polymerized in a water-soluble solvent as described below containing a polyalkylene glycol as shown below having a number average molecular weight of 0 and dispersed by adding water. There are several methods.

The polyalkylene glycol may be one or more of polyethylene glycol, polypropylene glycol, or a block copolymer of polyethylene glycol and polypropylene glycol.

Further, typical examples of the water-soluble solvents mentioned above include methanol,
Alcohols such as ethanol, globanol or butanol; cellosolve systems such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether or ethylene glycol monomethyl ether; diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol carpitol dl- such as 7noprobyl ethyl or diethylene glycol monomethyl ether, and also # conductors thereof can be used. The amount of violet to be used is preferably 20 to 100 parts by weight per 1 part by weight of JLI electric storage.

The polymerization using the vinyl monomer may be carried out by a conventional solution polymerization reaction method, and there is no particular restriction. The degree of reaction at this time is preferably 90°C or higher from the viewpoint of good grafting efficiency with the vinyl monomer, and any known monomer may be used as long as it has an appropriate amount for use in paints. Representative examples include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, hexamaric acid, phosphoric acid or itaconic acid;
Methyl acrylate, ethyl acrylate, acrylic acid 1-
propyl, isopropyl acrylate, aphrylmi ln-
Acrylic acid esters such as butyl, t-butyl acrylate, isobutyl acrylate or 2-ethylhexyl acrylate; methyl methacrylate, ethyl methacrylate, 1-propyl methacrylate, isoglobil methacrylate, methacrylate! Methacrylic stationary esters such as n-butyl, t-butyl methacrylate, isobutyl methacrylate or 2-ethylhexyl methacrylate; styrenic septamers such as styrene, vinyltoluene or α-methylstyrene; or vinyl acetate, acrylic β-hydroxyethyl methacrylate, β-hydroxyethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, acrylamide, methacrylamide, N,N-dimethylacrylamide, N,N-
Diethyl methacrylamide, acrylonitrile, methacrylonitrile, ethylene, vinyl chloride, dimethylaminoethyl methacrylate or diethylamine ethyl methacrylate, etc. are used, and these may be used in combination or as a mixture of two or more thereof.

The nucleation of these monomers is preferably carried out at 50 to 150°C in the presence of polyalkylene glycol and a radical polymerization initiator. As a radical polymerization initiator, oil-soluble radicals such as azobisisobutyonitrile, azobisvaleronitrile, benzoyl peroxide, or t-butylindrobaroquinide are used.
Synthesis initiators are useful.

The thus obtained solution of the polymer 11i1r in the water-soluble solvent is as follows.

Next, a resin dispersion is obtained by dispersing the resin in water, but the dispersion of this one-unit resin [i11 in water may be carried out by adding a resin solution into the water to disperse the resin]. Conversely, a method of injecting and dispersing water into the resin solution may also be used. In either case, the system is
It is desirable to gradually add and disperse the mixture while stirring and heating the mixture to a temperature in the range of 00°C.

The l1w dispersion obtained here can of course be used as it is or as a chemical *W for #i, a lubricant, a bath agent, or a wide range of water-bathable or water-dispersed materials such as polyester resins or acrylic resins. It is also possible to incorporate synthetic resins.

Next, the powder coating material can be easily dispersed into this resin dispersion using a conventional stirrer or kneader such as a roll mill, sand mill, or ball mill.

The mixing ratio of these resin dispersions and powder coating is i:t
o.

-100:1, preferably 5:95-7010.

Prior to dispersing the powder coating into such a resin dispersion,
When manufacturing powder coating W4, it is possible to mix conventional curing agent components, skin coloring agent components, and other additive components in advance with powder coating resin. This is a common practice, of course.

The thus obtained book @ Ming's Moisture Exchange is a gold I14 paint that can be used in a wide range of applications such as can manufacturing, pre-coated metal, automobiles, and home appliances. The invention will be explained in detail with reference to Reference Examples, Examples, and Comparative Examples, where all parts and volumes are based on 1 quantity unless otherwise specified.

Reference example 1 (Water dispersion I1M shield liquid 0llllll example) Stirrer, temperature needle, Rf! 2 with /L cooler, subordinate rate, and inert gas inlet! Ethyl Seltsurpro 00I, polyethylene glycol Luna 4000 70Ii in the flask.
Prepare it and 1 under the ill accumulated gas flow! Raise the temperature to IO°C. Separately, methyl methacrylate 47 as a beer monomer
6g% Otori-butyl acrylate) 210/, methacrylic acid 14. 14Ii of t-butyl hydroperoxide was weighed and mixed in advance, and 14Ii of t-butyl hydroperoxide was added to the mixture, and the mixture was injected from separate dropping ports to uniformly drop 1 cup over 5 hours. The temperature was further maintained at 160° C. for 2 hours to complete the polymerization.

Next, the mixture was cooled to 80°C, and 876 g of water was added dropwise at the same temperature for 2 hours to achieve dispersion, and then cooled to 25°C.

The resin dispersion thus obtained had a nonvolatile content of 40%, a viscosity of 250 cps, a pH of 5.4, and an average particle size of 0.2 μm.
It was below.

Reference Example 2 (Same as above) Using the same apparatus as in Example 1, ethylene glycol monoisoglobyl ether 5 Ll 017. Pour polyethylene glycol ÷ 6000 100.9 and raise the temperature to 100°C in a gas atmosphere. Separately, as vinyl monomers, 441 g of methyl methacrylate, 224 L of 2-ethylhexyl methacrylate, and 35 y of dimethylaminoethyl methacrylate were mixed in advance on a scale.
At the same time, 5 g of t-bunalboxy-2-ethylhexanoate was added to the mixture and injected from separate injection ports to uniformly dropwise polymerize over 5 hours.

Further, the temperature was maintained at 100° C. for 2 hours to complete the polymerization.

Next, the mixture was cooled to 90°C, water 907Ii was added dropwise at the same temperature over 2 hours to divide the mixture, and the mixture was cooled to 25°C.

The resin dispersion thus obtained had a nonvolatile content of 40-1, a viscosity of 110 cps%, a pH of &1, and an average particle diameter of α2 μm or less.

Reference Example 5 (Genuine example of powder coating) “FINDIC M-s1osJ (Carboxyl group-containing polyester lf* manufactured by Dainippon Ink & Chemicals) 5
001S.

500 parts of "Evicron 30so" (epoxy resin manufactured by LJJL Kamisha), 500 parts of titanium oxide, "Acronal 4"
FJ ($!! 7 bus companies in Germany ll4rILIjk agent)
5 parts and 1i1t of 2-methylimidazole, mixed;
After melting and kneading in an extruder, it was pulverized in a jet mill to obtain a powder coating with a particle size of 1 to 30 μm. ) 900g, Dodecanni rice 1
00 parts, 400 parts of titanium oxide and "Achronal 4F
After mixing 5 parts, they were melted and kneaded in an extruder, and then pulverized to form 4 grains! ! A powder powder having a diameter of 1 to 20 μm was obtained.

Example 1 In a ball mill, 1 of the water dispersion *&& obtained in Reference Example 1
00g, add 100s of water and 100g of the powder coating prepared in Reference Example 3, and knead for 10 minutes to obtain a water-dispersed coating.

Example 2 In a ball mill, 60 parts of the powder coating obtained in Reference Example 4 was added to 100 parts of the moisture #X resin liquid obtained in Reference Example 2, and dispersed for 5 minutes to obtain a water-dispersed coating. Ta. Hereinafter, this will be referred to as "moisture 1-1".

Comparison? I11 Water dispersion area Instead of WI liquid, use the same amount of "Watersol 5-727J (water-based acrylic resin at Prl Kamisha Exhibition;
[
It is called water dispersion paint A.

Claims (1)

[Claims] A water-insoluble powder coating is dispersed in a *ti' dispersion in which a polymer resin obtained by polymerizing polymerizable vinyl mono i- is dispersed in water in a solution of a water-soluble solvent in which polyalkylene glycol is dissolved. A water-dispersed paint made of at least