JPS5918425B2 - UV curing emulsion paint - Google Patents

Description

Detailed description of the invention: Allyl ether of polyhydric alcohol, unsaturated polyester obtained by reacting polybasic acid and polyhydric alcohol, vinyl monomer, photopolymerization initiator, and pigments and various additives as necessary. UV-curable unsaturated polyester paints with additives have been known for a long time, and with the advent of such paints, the paint film can be cured in a short time, and it is superior to conventional paints in terms of adhesion, surface hardness, smoothness, etc. It has become possible to obtain painted products of even higher quality.

However, since the UV-curable unsaturated polyester resin paint contains a fairly large amount of vinyl monomer as a crosslinking component, these vinyl monomers evaporate during painting and during curing and drying after painting, resulting in odor, toxicity, fire, etc. This causes various harmful effects. Furthermore, when cleaning paint manufacturing equipment and painting equipment, it is necessary to use organic solvents, which not only increases costs due to the use of solvents, but also poses problems such as fire danger and inhalation into the human body. As a result of various studies, the present inventors have found that an emulsion can be easily obtained when a conventionally known ultraviolet curable unsaturated polyester resin is dispersed together with a crosslinkable vinyl monomer in water in the presence of an emulsifier. He discovered this and filed an application as Japanese Patent Application No. 130443/1983.

The above emulsion paint has the following properties. That is, 1
Evaporation of the vinyl monomer is almost completely suppressed, greatly reducing odor, toxicity and fire hazards.

2. The stability of the emulsion is extremely good even when left at high temperatures for a long period of time.

3. Even if it is an aqueous emulsion, the curing speed hardly decreases.

It also has a much faster curing speed than regular water-based paints. 4
The resulting coating film has good adhesion to the substrate, high surface hardness, and rich smoothness.

5. Paint manufacturing equipment and painting equipment can be easily cleaned with water, making them extremely workable, and there are no problems or disadvantages such as fire, inhalation, high cost, etc. caused by the use of organic solvents.

However, as a result of further investigation by the present inventors,
It is possible to obtain an emulsion paint having the performance listed above without using a vinyl monomer when emulsifying an ultraviolet curable unsaturated polyester resin, and since the emulsion paint thus obtained does not use a vinyl monomer, there is no odor or toxicity. They discovered that it is possible to completely eliminate pollution in terms of fire, and have completed the present invention.

Allyl ethers of polyhydric alcohols used in the production of the unsaturated polyester used in the present invention include mono- or diallyl ethers of glycerin, trimethylolpropane, trimethylolethane, mono-, di- or triallyl ethers of pentaerythritol, and allylglycidyl ethers. , allyloxydicyclopentadiene, partially allyl etherified products of the initial condensate of funinol-formaldehyde, and also partially allyl etherified products of the initial condensate of urea or melamine and formaldehyde.

Next, as polybasic acids, maleic anhydride, fumaric acid,
Examples include itaconic acid, tetrahydrophthalic anhydride, phthalic anhydride, adipic acid, sebacic acid, and trimellitic acid.

Polyhydric alcohols include ethylene glycol, propylene glycol, glycerin, diglycerin, 1,3
-Butylene glycol, diethylene glycol, triethylene glycol, neopentyl glycol, polyethylene glycol, polypropylene glycol, trimethylolethane, trimethylolpropane, pentaerythritol, and the like. In addition to the above-mentioned modifiers, oils such as tung oil, linseed oil, dehydrated castor oil, and soybean oil, or their fatty acids may be used as modifiers when preparing unsaturated polyesters. The unsaturated polyester can be obtained as a viscous liquid by heating and condensing it at 180 to 210C in accordance with a conventional method with these allyl ethers, polybasic acids, polyhydric alcohols, and if necessary a modifier. be.

Although the molecular weight of such unsaturated polyester is not particularly limited, it usually has an average molecular weight of 1000 to 2000.
A range of 0 is used. As a photopolymerization initiator, benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin phenyl ether, 2-
Phenylthioacetophenone, benzyl, anthraquinone, naphthoquinone, azopisisobutyronitrile, 2,
2'-azobis-2,4-dimethylvaleronitrile, benzoyl peroxide, di-t-butyl peroxide, diphenyl disulfide, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram monosulfide , tetraethylthiuram disulfide, benzophenone, pivaloin ethyl ether, dipendyl disulfide, cinnamoyl chloride, dimethyldiphenylene disulfide, dibenzothiazole disulfide, etc., but are not limited to these. It's not a thing.

Emulsifiers for emulsifying resins and photopolymerization initiators in water include polyvinyl alcohol, polyvinyl alcohol derivatives, anionic surfactants, cationic surfactants, nonionic surfactants, carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, etc. These may be used alone or in combination of two or more.

Emulsification is usually carried out by forcibly stirring and mixing an unsaturated polyester resin liquid to which a photopolymerization initiator has been added with water in the presence of an emulsifier.

The paint of the present invention may contain fillers, colorants, pigments, and other paint additives as required. The additive may be added to the resin liquid or to the emulsion after preparing the emulsion. The coating method is not particularly limited, and may include spraying, brush coating, curtain flow coating, and roll coating. , spatula attachment method, etc. are all adopted.

The most common base materials for painting are wood-based materials such as precious wood plywood, decorative paper plywood, and particle board, but other materials such as plastic materials, metal materials, and inorganic materials (slate board,
(pulp cement board, calcium silicate board, gypsum board, etc.) are also used. In this case, the coating composition of the present invention may not be directly applied to the substrate, but the substrate may be first coated with a urethane-based lacquer, cellulose-based lacquer, etc., and then the coating composition of the present invention may be topcoated as appropriate. It will be done. In ultraviolet irradiation, ultraviolet light has a wavelength of 300 to 400 mμ.

Next, the coating material of the present invention will be further explained by giving an example.

Hereinafter, "parts" refer to parts by weight. Example 1 In a four-bottle flask, 1.0 mole of maleic anhydride, 0.5 mole of propylene glycol, and 0.5 mole of triethylene glycol.
4 mol, trimethylolpropane diallyl ether 0.
35 mol and 109 mol of linseed oil fatty acid were charged and reacted at 180° C. for 8 hours with stirring, and when the acid value reached 32 ηKOH/9, the pressure was reduced to remove unreacted substances.

Next, the temperature of the reaction solution was lowered to 130°C, 5 parts of benzoin isopropyl ether was added, and a nonionic activator (Epan 785 manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was heated to 80°C in advance.
It was gradually poured into a 3% aqueous solution 1109 while stirring with a homomixer, and after the flow was finished, stirring was continued for an additional 15 minutes. As a result, an emulsion with a concentration of 60%, a viscosity of 560 cps (20°C), and an average particle size of 800 mμ was obtained. . The emulsion has extremely good stability and does not cause problems such as gelation or separation even if it is left at room temperature for 6 months or more. Next, apply the above emulsion to decorative paper plywood at a ratio of 909/I using a natural roll coater, and immediately apply 1KW
20Cf height with far infrared light! A uniform transparent coating film was obtained by irradiating infrared rays for 2 minutes from a distance of L, and then irradiating ultraviolet rays for 30 seconds from a distance of 150 fIL using a high-pressure mercury lamp.

This coating film had excellent adhesion and flexibility, and the equipment required for coating could be easily cleaned with water.

Furthermore, emulsions were prepared according to Example 1 with various types of polybasic acids, polyhydric alcohols, and allyl ethers and applied for coating, and the same good results as in Example 1 were obtained.

Example 2 Maleic anhydride 68.59, phthalic anhydride 44.49
, 729 g of 1,3-butylene glycol, 134 g of dipropylene glycol, and 0.03 g of hydroquinone were placed in a four-necked flask, and reacted with stirring at 200° C. for 8 hours in a nitrogen atmosphere.

Then, the reaction temperature was lowered to 80° C., tolylene diisocyanate 1109 was added dropwise over 1 hour, and after further stirring for 3 hours, bentaerythritol triallyl ether 1039 was added dropwise over 2 hours at that temperature, and the reaction was continued for another 2 hours. continued. The acid value of the reaction solution is 8.6 to KOH/9,
The hydroxyl value was 16.5 to KOH/9. 15 g of penzoin ethyl ether was added to the reaction solution. water 100
A solution in which polyvinyl alcohol 109 and a nonionic anionic emulsifier (Levenol WZ manufactured by Kao Atlas Co., Ltd.) 59 were dissolved in 9 was heated to 80°C, and the above benzoin ethyl ether was added to this while stirring with a homomixer to obtain a reaction solution 1009. The solution heated to 100° C. was gradually allowed to flow down, and after the end of the flowing down, the solution was further stirred for 15 minutes. As a result, an emulsion with a concentration of 50%, a viscosity of 880 cps (at 20° C.), and an average particle size of 500 mμ was obtained.

50 parts of calcium carbonate and 70 parts of talc were added to 100 parts by weight of this emulsion and mixed in a second oven for 1 hour to prepare an ultraviolet curable paint. The coating was applied using a reverse roll coater at a ratio of 1209/A, irradiated with a 1KW far-infrared lamp for 30 seconds from a distance of 15cm in height, and then with a high-pressure mercury lamp at a height of 8cm. Ultraviolet rays were irradiated for 20 seconds from a distance of .

When the cured coating film was polished with #240 sandpaper and an enamel lacquer was applied thereon, a high-quality coated board with excellent smoothness, water resistance, weather resistance, and heat resistance test was obtained.

Claims (1)

[Claims] 1. An ultraviolet curable emulsion paint made by emulsifying an allyl ether of a polyhydric alcohol, a vinyl monomer-free unsaturated polyester containing a polybasic acid and a polyhydric alcohol, and a photopolymerization initiator together with water and an emulsifier.