JPH0133506B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to a water-soluble paint composition for tatami mats for coating and coloring old tatami mats. Traditionally, tatami mats installed indoors, etc. have been subject to wear and tear due to movement of people, dirt, or discoloration due to sunlight, etc. over time, and tatami mats or tatami mats stored in warehouses etc. have also had the problem of gradually discoloring. Ta. These are not only extremely unsightly in appearance, but also undesirable from a sanitary standpoint. When the above-mentioned defects become serious, the tatami mats are generally turned over or replaced with new tatami mats, but such work is not only extremely time-consuming, but cannot be done by the average person and requires special care. This had to be done by a skilled craftsman, which required a large amount of money. Recently, it has become common practice to apply a certain kind of paint to tatami mats before use or after long-term use. For example, there is a method in which a small amount of a composition consisting of a synthetic or natural resin emulsion and a coloring agent is sprayed onto the tatami surface before use (Japanese Patent Publication No. 56588/1988), or various methods are used to paint or finish the tatami surface after use. Those using emulsion and coloring agent (JP-A-48-31234, JP-A-Sho
50-101430, Japanese Patent Publication No. 47-44012, and Japanese Patent Publication No. 58-44434) are known. As mentioned above, most of the conventional compositions for tatami mats use natural or synthetic resin emulsions as color vehicles. Therefore, when these known compositions are applied to a tatami surface, the emulsion particles do not penetrate into the rush, and a film is formed by the emulsion particles coalescing on the surface of the rush during the drying process. As a result, a fairly thick continuous film is formed on the tatami surface. The surface of the rushes used for tatami mats has a fine uneven linear pattern, and the rushes are woven in a delicate and precise manner, giving people a three-dimensional feel and a unique feel. However, if the tatami mat is covered with a thick film as described above, it becomes completely impossible to obtain the original appearance and feel of the tatami mat, and the air permeability and hygroscopicity of the tatami mat are significantly reduced. Furthermore, conventional emulsion-type compositions have extremely poor storage stability (freezing stability), poor coating workability such as uneven coating, and poor abrasion resistance, water resistance, etc. of the resulting film. Its performance was poor, and there was still room for improvement in practical terms. The present inventors have arrived at the present invention as a result of intensive research aimed at solving the problems of conventional compositions as described above. The purpose of the present invention is to apply it to discolored or dirty tatami surfaces to give them a beautiful finish.
A water-soluble paint for tatami surfaces that not only has good freezing stability but also good application workability and drying properties, and the resulting film has excellent performance such as appearance, abrasion resistance, water resistance, and adhesion. A composition is provided. That is, the present invention provides (a) an alkyl ester of acrylic acid or methacrylic acid (however, the number of carbon atoms in the alkyl group is 1 to 8)...70 to 95% by weight, (b) α,β-monoethylene unsaturated carboxylic acid
...5 to 12% by weight, and (c) α,β-monoethylenically unsaturated monomer other than the above (a) and (b) ...0 to 25% by weight, acid value 30 to 120, Glass transition temperature 5-20
℃ and has a weight average molecular weight of 5,000 to 60,000, a water-soluble paint composition for tatami surfaces comprising a neutralizing agent for the copolymer, a coloring agent, and water. Examples of the alkyl ester of acrylic acid or methacrylic acid (provided that the alkyl group has 1 to 8 carbon atoms) forming the copolymer used in the composition of the present invention include, for example, methyl acrylate, Ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, methacrylic acid Isobutyl, t-butyl methacrylate,
Examples include 2-ethylhexyl methacrylate and hydroxyalkyl esters, such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate, which may be used alone or as a mixture of two or more. . Further, (b) α,β-monoethylenically unsaturated carboxylic acids forming the copolymer include acrylic acid, methacrylic acid, maleic anhydride, itaconic acid, etc., and these may be one or more types. used as a mixture of Further, (c) α,β-monoethylenically unsaturated monomers other than the above that form the copolymer include sterene, vinyltoluene, acrylonitrile, glycidyl methacrylate, lauryl methacrylate, vinyl acetate, etc. These may be used singly or as a mixture of two or more, if necessary. In the copolymer used in the present invention, the component (a) is 70 to 95% by weight, preferably 80 to 90% by weight, and the component (b) is 5 to 12% by weight, preferably 6 to 10% by weight.
% by weight, and the component (iii) is used in a proportion of 0 to 25% by weight, preferably 0 to 14% by weight. In the above range, if component (a) is less than 70% by weight and component (b) is less than 5% by weight, the other component (c) will inevitably be in a large amount and the copolymer will not be water-soluble. Therefore, the abrasion resistance of the resulting film and the permeability of the paint are reduced, as with conventional emulsion type compositions, and when the component (a) is less than 70% by weight, the component (b) is less than 12% by weight. % or more, the water resistance, hot water resistance, etc. of the resulting film decreases, which is not preferable. Furthermore, if the amount of component (a) exceeds 95% by weight, the copolymer will not become water-soluble, resulting in the same drawbacks as mentioned above. The acid value (copolymer solid content) of the copolymer obtained from the above component ratios is 30-120, preferably 40-120.
100, the glass transition temperature is 5 to 20°C, and the weight average molecular weight is 5,000 to 60,000, preferably 10,000 to 40,000. If the acid value is less than 30, the copolymer cannot be made water-soluble, so the above-mentioned drawbacks of the emulsion type composition cannot be improved; on the other hand, if the acid value exceeds 120, the water resistance of the film will decrease significantly. However, neither is preferable. Furthermore, if the glass transition temperature is less than 5°C, the film will remain sticky and prone to blocking, whereas if it exceeds 20°C, the film will become hard and brittle, reducing wear resistance, both of which are undesirable. . Further, if the weight average molecular weight is less than 5,000, drying becomes slow and the water resistance of the film decreases, while if it exceeds 60,000, it becomes difficult to dissolve in water, which is not preferable. The copolymer used in the present invention can be prepared by conventional polymerization methods, such as solution polymerization in a solvent followed by solvent replacement and neutralization, solution polymerization in a water-soluble solvent,
It is produced by neutralizing and diluting with water, or by emulsion polymerization and then neutralizing to make it water-soluble. A neutralizing agent is used in the coating composition of the present invention. Examples of the neutralizing agent include ammonia and organic amines, and these neutralizing agents are used to neutralize the copolymer and make it water-soluble. As the organic amine, those commonly used as neutralizing agents for water-soluble coating compositions, such as dimethylamine, diethylamine, monoethanolamine, diethanolamine, etc., can be used without any problem. The neutralizing agent such as ammonia or organic amine is preferably used in an amount of 1 to 20 parts by weight per 100 parts by weight of the copolymer. If the amount of neutralizing agent such as ammonia or organic amine used is less than 1 part by weight, it will be difficult to make the copolymer water-soluble, and if it is used in excess of 20 parts by weight, odor etc. Disadvantages such as unfavorable hygiene are likely to occur. A coloring agent is used in the coating composition of the present invention. The colorant has a particle size of 10 μm or less, preferably 5 μm or less, in an amount of 40 to 40 μm per 100 parts by weight of the copolymer.
It is preferable to use it in a proportion of about 200 parts by weight.
The particle size of 10μ or less refers to particles with a maximum particle size of 10μ or less. It is not preferable to use a coloring agent with a particle size of more than 10 μm because the permeability into the tatami surface, which is a characteristic of the composition of the present invention, decreases. If the amount of coloring agent used is less than 40 parts by weight, the effect of coloring the old tatami surface will not be sufficient, and conversely, if more than 200 parts by weight is used, uneven coating will occur. Both of these are not very preferable because they tend to deteriorate the appearance very easily and also tend to reduce the permeability. As the coloring agent, one type or a mixture of two or more types of pigments such as titanium oxide, iron oxide yellow, copper phthalocyanine, halogenated copper phthalocyanine, and other dyes can be used. Furthermore, water is used as a diluent in the coating composition of the present invention. It is preferable to use water in a proportion of about 250 to 400 parts by weight per 100 parts by weight of the copolymer. In addition, in order to further improve the permeability of the coating composition into the tatami surface and to assist in the production and water solubility of the copolymer, methyl alcohol, ethyl alcohol, isopropyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, and diethylene glycol are added. Water-soluble solvents such as monomethyl ether, dioxane, acetone, etc. may be used to replace up to 50% by weight of the water used. In particular, when using a copolymer with an acid value of 30 to 50, it is preferable to use the water-soluble solvent described above in order to improve its water solubility. Furthermore, in the coating composition of the present invention, when the glass transition temperature of the copolymer used is relatively high (5°C or higher), diacetone alcohol, diethylene glycol monobutyl ether, 2,2,4-
It is preferable to use a film forming aid such as trimethyl-1,3-pentanediol monoisobutyrate in an amount of 25% by weight or less, preferably about 5 to 20% by weight, based on the copolymer. In the thus obtained water-soluble paint composition for tatami surfaces of the present invention, other ingredients such as extender pigments, plasticizers, antifoaming agents, surfactants, fragrances, and other additives may be added and mixed as necessary. It can be used as The coating composition of the present invention is made into a coating by mixing the respective components and then kneading them using a common kneading method such as a sand grinder. The water-soluble paint composition for tatami surfaces of the present invention obtained as described above is diluted with water if necessary at the time of painting, and applied to old tatami surfaces by a conventional method such as a brush, roller or spray, and dried to finish. . Rush, which is normally used for tatami mats, has fine linear irregularities, and the tatami mat made from woven rush grass has minute gaps, so when conventional emulsion-type compositions are applied, they cannot penetrate into the inside. It doesn't seep through. This is because the emulsion resin system has high thixotropy and low fluidity, and the emulsion particles form a film by agglomeration and adhesion of particles on the surface layer. In such surface film formation systems, films with excellent adhesion can be obtained when the glass transition temperature is 35°C or lower, but on the other hand, transferability to clothing, stain resistance, and abrasion resistance are significantly reduced. The problem arises that the amount of energy decreases. Furthermore, rush is slightly alkaline (PH
7.6 to 8.0), it is difficult to obtain a uniform film with good adhesion using an emulsion resin with a low acid value. On the other hand, the water-soluble paint composition of the present invention easily permeates into the minute gaps of rush and tatami surfaces, exerts an internal reinforcing effect, and even when the glass transition temperature is low (5 to 20°C), After drying, the film does not transfer to clothing, and it is possible to form a film with excellent adhesion and excellent stain resistance and abrasion resistance. Furthermore, since the copolymer used in the composition of the present invention becomes weakly acidic during coating, a coating with good adhesion can be obtained. Therefore, the water-soluble coating composition of the present invention has great practical value in this industry. Hereinafter, the details of the present invention will be explained with reference to Examples. Note that "parts" or "%" indicate "parts by weight" or "% by weight." Example 1 200 parts of water, 1.5 parts of nonionic surfactant, 0.1 part of sodium bicarbonate, and 0.03 parts of potassium persulfate were placed in a reaction vessel, while 50 parts of butyl methacrylate and 10 parts of methyl methacrylate were placed in a dropping funnel. After charging 24 parts of ethyl acrylate, 7 parts of 2-ethylhexyl methacrylate, and 9 parts of acrylic acid, the temperature of the container was raised to 80°C, and the monomer mixture in the dropping funnel was added dropwise at the same temperature while stirring. After 2 hours, the temperature was raised to 85°C, and the reaction was continued at the same temperature for an additional 3 hours. Next, a mixed solution of 100 parts of water and 10 parts of aqueous ammonia (28% aqueous solution) was gradually added under stirring to obtain a water-soluble copolymer resin solution () with a non-volatile content of 24%. Ta. The copolymer resin (solid content) obtained as described above had an acid value of 70.1, a glass transition temperature of 16.7°C, a weight average molecular weight of about 32,000, and a resin solution ().
Its pH was 9.0 and its viscosity was 10 poise (20°C). 66 parts of the water-soluble copolymer resin solution (), 23.1 parts of titanium oxide, 0.33 parts of copper phthalocyanine blue,
4.9 parts of iron oxide yellow, 2 parts of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate as a coating aid, 0.4 parts of silicone antifoaming agent, and 4 parts of water.
A water-soluble coating composition of the present invention having a pH of 9.0 and a viscosity of 76 KU (at 20° C.) was obtained by kneading the mixture consisting of the following parts using a sand glider. Example 2 200 parts of water, 2.0 parts of nonionic surfactant, 0.1 part of sodium bicarbonate, and 0.1 part of potassium persulfate were placed in a reaction vessel and the temperature was raised to 80°C, and then 27 parts of methyl methacrylate was added from the dropping funnel. Butyl methacrylate 30 parts, butyl acrylate 30 parts, methacrylic acid 2
- A mixture consisting of 3 parts of ethylhexyl, 10 parts of acrylic acid and 0.5 parts of dodecyl mercaptan was gradually added dropwise, and after the addition was completed, the temperature was raised to 85°C and the reaction was continued for an additional 3 hours. Then, a mixture of 100 parts of water and 11 parts of diethylamine was gradually added with stirring to obtain a water-soluble copolymer resin solution (2) with a nonvolatile content of 26%. The acid value of the copolymer resin (solid content) is 77.9, the glass transition temperature is 17.5°C, and the weight average molecular weight is approximately
25,000, the pH of the resin solution () was 9.5, and the viscosity was 4 poise (20°C). Said water-soluble copolymer resin solution () 80 parts, titanium oxide 10 parts, iron oxide yellow
1.8 parts, polychlor copper phthalocyanine green 0.4
1 part, 3 parts of coating aid (same as Example 1), 0.4 parts of silicone antifoaming agent, and 3 parts of water were mixed in a sand grinder to give a pH of 9.2 and a viscosity of 68 KU.
(20° C.) A water-soluble coating composition of the present invention was obtained. Example 3 60 parts of ethylene glycol monoethyl ether was placed in a reaction vessel, the temperature was raised to 80°C, and then 25 parts of methyl methacrylate, 30 parts of butyl acrylate, 40 parts of butyl methacrylate, and 5 parts of methacrylic acid were added from the dropping funnel. A mixture consisting of 0.8 parts of azobisisobutyronitrile and 0.8 parts of azobisisobutyronitrile was gradually added dropwise over 2 hours, and after the addition was completed, the temperature was raised to 90°C and the reaction was continued at the same temperature for 5 hours. Then, a mixture consisting of 90 parts of water and 5.5 parts of diethylamine was gradually added with stirring to obtain a water-soluble copolymer resin solution (2) with a nonvolatile content of 41%. The acid value of the copolymer resin (solid content) is 32.6, the glass transition temperature is 11.3°C, and the weight average molecular weight is approximately
20,000, and the viscosity of the resin solution () was 15 poise (20°C). 80 parts of the water-soluble copolymer resin solution (), 11.05 parts of titanium oxide, 0.13 parts of copper phthalocyanine blue,
Iron oxide yellow 2.4 parts, film auxiliary agent (same as Example 1) 4
A mixture of 1 part, 0.4 parts of silicone antifoaming agent, and 3 parts of water was kneaded in the same manner as above, and the mixture had a pH of 9.5 and a viscosity of 80 KU.
(20° C.) A water-soluble coating composition of the present invention was obtained. Example 4 25 parts of methyl methacrylate, butyl methacrylate
23 parts, butyl acrylate 30 parts, methacrylic acid 2-
A water-soluble copolymer resin solution (2) with a nonvolatile content of 24% was obtained in the same manner as in Example 1 from 10 parts of ethylhexyl and 12 parts of methacrylic acid. The acid value of the copolymer resin (solid content) is 78.2, the glass transition temperature is 11.6°C, and the weight average molecular weight is approximately
30,000, and the viscosity of the resin solution () was 30 poise (20°C). 75 parts of the water-soluble copolymer resin solution (), 12.6 parts of titanium oxide, 0.15 parts of copper phthalocyanine blue,
Iron oxide yellow 2.7 parts, film auxiliary agent (same as Example 1) 3
0.4 parts of silicone antifoaming agent, and 6 parts of water were kneaded in the same manner as above to obtain a pH of 9.0 and a viscosity of 85 KU.
(20° C.) A water-soluble coating composition of the present invention was obtained. Comparative Example 1 100 parts of water and nonionic surfactant in reaction vessel
4.2 parts of sodium bicarbonate, 0.14 parts of sodium hydrogen carbonate, and 0.25 parts of potassium persulfate, while in the dropping funnel were added 26 parts of methyl methacrylate and 24.5 parts of butyl methacrylate.
1 part, 33 parts of 2-ethylhexyl acrylate, 13 parts of styrene, and 3.5 parts of methacrylic acid, and after raising the temperature of the reaction vessel to 75°C, the monomer mixture in the dropping funnel was added dropwise over 4 hours while stirring. After completion of the dropwise addition, the temperature was raised to 80°C and emulsion polymerization was carried out for 3 hours. Next, 6 parts of water and dimethylethanolamine
Gradually add the mixture consisting of 1.46 parts and remove the non-volatile content.
A 48% copolymer emulsion resin liquid was obtained. The acid value of the copolymer emulsion (solid content) is
22.8, the glass transition temperature was 18.7°C, the weight average molecular weight was about 40,000, and the viscosity of the copolymer emulsion resin liquid was 18 poise (20°C). 12.5 parts water,
0.5 parts of nonionic surfactant, 0.15 parts of dimethylethanolamine, 21 parts of titanium oxide, 0.3 parts of copper phthalocyanine blue, 4.5 parts of iron oxide yellow, 0.8 parts of anionic surfactant, and 0.2 parts of silicone antifoaming agent were mixed in advance. 100 parts of the resulting mill base was mixed with 200 parts of the copolymer emulsion resin liquid to obtain an emulsion coating composition of a comparative example. The coating compositions obtained in Examples 1 to 4 and Comparative Example 1 were applied onto old tatami mats using a sponge brush and subjected to comparative tests. The results are shown in the table below.

【table】

[Table] As is clear from the comparative test results table, the water-soluble coating composition of the present invention has excellent storage stability, short drying time, and the resulting film has excellent abrasion resistance, water resistance, and resistance. It was extremely excellent in hot water resistance and accelerated weathering resistance. On the other hand, conventionally known emulsion-type coating compositions have significantly poor storage stability, drying time, and permeability, and the resulting coating film has poor hot water resistance, abrasion resistance, and accelerated weathering resistance. The properties were also several orders of magnitude inferior to those of the present invention.

Claims (1)

[Scope of Claims] 1 (a) Alkyl ester of acrylic acid or methacrylic acid (provided that the number of carbon atoms in the alkyl group is 1 to 1)
(8) ...70-95% by weight, (b) α,β-monoethylenically unsaturated carboxylic acid
...5 to 12% by weight, and (c) α,β-monoethylenically unsaturated monomer other than the above (a) and (b) ...0 to 25% by weight, acid value 30 to 120, Glass transition temperature 5-20
A water-soluble paint composition for tatami surfaces, comprising a copolymer having a weight average molecular weight of 5,000 to 60,000 at a temperature of 0.degree. C., a neutralizing agent for the copolymer, a coloring agent, and water.