JPH01289875A - Coating composition - Google Patents

Abstract

PURPOSE:To obtain a coating composition which can absorb moisture and water formed by condensation in good efficiency and can prevent dew condensation from occurring on the surface of a coating film under conditions of dew condensation by mixing a specified synthetic resin emulsion with a water-soluble complex compound and a porous inorganic substance. CONSTITUTION:A porous inorganic substance (e.g., zeolite or silica gel) is added to a mixture formed by dispersing a water-soluble complex compound comprising a bivalent or higher valent metal salt and a volatile complexing agent [e.g., one formed by adding ZnO and (NH4)2CO3 in water and adding ammonia water thereto so that the pH is 7 or above and agitating the mixture] and a synthetic emulsion comprising 0.1-30wt.% ethylenically unsaturated carboxylic acid [e.g., (meth)acrylic acid or maleic acid (anhydride)] and 99.9-70wt.% monomer copolymerizable therewith (e.g., methyl (meth)acrylate). A coating composition which can absorb moisture or water formed by condensation in good efficiency under conditions of dew condensation and can prevent dew condensation from occurring on the surface of a coating film can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a coating composition that prevents dew condensation on areas where condensation is likely to occur, such as walls, ceilings, and piping of buildings.

(Prior art) Various methods have been proposed to prevent dew condensation.
A paint as disclosed in Publication No. 2-15108, that is, a paint containing a porous inorganic material such as zeolite, diatomaceous earth, or silica gel as a filler is applied to the film-forming element of a synthetic resin emulsion. There is a method to prevent condensation in the form of droplets by adding moisture or condensation water to the surface.

(Problem to be Solved by the Invention) However, since synthetic resin emulsions are essentially hydrophilic, they may contain a large amount of condensed water in the coating film for a long period of time, or may be exposed to water in the bathroom etc. However, there was a problem in that the hydrophilic component part was washed away, the ability to bind the porous filler, that is, the performance as a binder was weakened, and the coating film was lost.

An object of the present invention is to provide a coating composition that prevents dew condensation and does not cause loss of the coating film even if a large amount of dew water is contained in the coating film for a long period of time or water is splashed onto the coated surface.

(Means for solving the problem) As a result of studying synthetic resin emulsions that provide a paint film with a long pot life and good water resistance, we found that 0:1 to 30% by weight of ethylenically unsaturated carboxylic acid and ethylenic A mixture of a synthetic resin emulsion consisting of an unsaturated carboxylic acid and 99.9 to 70% by weight of a copolymerizable monomer, and a water-soluble complex consisting of a divalent or higher valent metal salt and a volatile complexing agent. After learning that the paint film was stable for a long time and had good water resistance, he discovered that by adding a porous inorganic substance to the above mixture, a water-resistant anti-condensation paint could be obtained, and thus completed the present invention. Na.

The ethylenically unsaturated carboxylic acids used in the present invention include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, and maleic anhydride.

The amount of ethylenically unsaturated carboxylic acid used is 0.1
-30% by weight, preferably 1.5-5% by weight.

If it is less than 0.1% by weight, crosslinking with the water-soluble complex will be insufficient, resulting in poor water resistance and film-forming properties.

Moreover, if it exceeds 30% by weight, the water resistance decreases and it is not suitable for practical use.

Monomers copolymerizable with ethylenically unsaturated carboxylic acids used in the present invention include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, butyl methacrylate,
Alkyl esters of ethylenically unsaturated carboxylic acids such as 2-ethylhexyl methacrylate and stearyl methacrylate, hydroxyalkyl esters of ethylenically unsaturated carboxylic acids such as 2-hydroxyethyl methacrylate, and ethylenically unsaturated carboxylic acids such as glycidyl methacrylate. Glycidyl esters of acids, amide compounds of ethylenically unsaturated carboxylic acids such as acrylamide, N-methylolacrylamide, N-butyrolacrylamide, vinyl esters such as vinyl acetate, allyl esters such as allyl acetate,
Examples include vinyl ethers such as vinyl methyl ether, vinylidene chloride, vinyl chloride, acrylonitrile, and ethylene.

The synthetic resin emulsion used in the present invention can be produced by a known emulsion polymerization method using an ethylenically unsaturated carboxylic acid and a monomer copolymerizable with the ethylenically unsaturated carboxylic acid. The resin concentration in the emulsion is usually 20
It is used in the range of ~65%.

The water-soluble complexes consisting of divalent or higher metal salts and volatile amines used in the present invention include carbonates, phosphates, etc. of zinc, nickel, copper, titanium, molybdenum, cobalt, iron, etc.
Salts of inorganic substances such as phosphites, or salts of organic substances such as phenol carboxylic acids, sorbic acids, and humic acids, and volatile complexes such as ammonia or volatile amines such as trimethylamine, diethylamine, triethylamine, triethanolamine, and morpholine. It is a water-soluble complex with 1 drug. Although not particularly limited, an example of a method for producing a water-soluble complex is to disperse zinc oxide and ammonium carbonate in water, and add aqueous ammonia to this so that the pH becomes 7 or more. By stirring, an aqueous solution of the water-soluble compound can be obtained. Regarding the water-soluble complexes mentioned above, JP-A No. 4
It is also disclosed in Japanese Patent Application Laid-open No. 9-96033 and Japanese Patent Application Laid-Open No. 62-257972.

The above-mentioned water-soluble complex has a carboxyl group derived from ethylenically unsaturated carboxylic acid contained in the synthetic resin emulsion.
It is preferable to use the water-soluble complex in a proportion of 0.2 to 1.5 moles per mole; if the proportion of the water-soluble complex is less than 0.2 mole, the degree of crosslinking with the water-soluble complex is insufficient; Water resistance is poor, and if the amount exceeds 1.5 mol, more hydrophilic components than necessary will be present in the coating film, resulting in decreased water resistance and may not be suitable for practical use.

Porous inorganic substances used in the present invention include zeolite,
diatomaceous earth, silica gel, perlite, etc., and the porous inorganic material is 100 to 600 parts by weight, preferably 150 to 400 parts by weight, per 100 parts by weight of the solid content of the synthetic resin emulsion.
If the amount of porous hot Ti material is less than 100 parts by weight, the amount of synthetic resin emulsion will be relatively large, and most of the surface of the porous hot Ti material will be covered. Water absorption capacity decreases, resulting in poor dew condensation prevention. Moreover, if it exceeds 600 parts by weight, the amount of synthetic resin emulsion will be relatively small, and the binding strength will be poor.
The water resistance of the paint film deteriorates.

The coating composition of the present invention may contain various additives used in general water-based coatings as long as the purpose of the present invention is not impaired. These additives include dispersants, antifoaming agents,
Wetting agents, emulsifiers, antistatic agents, coating aids, freeze stabilizers,
Examples include reversible agents, thickeners, preservatives, pigments, dyes, and aggregates.

(Effects of the invention) The coating composition of the present invention has
Under conditions where condensation occurs, moisture or condensed water can be efficiently absorbed, and dew condensation can be prevented from occurring on the coating surface. Furthermore, the carboxyl group contained in the synthetic resin emulsion and the divalent or higher valent metal form a strong ionic bond,
It forms a coating film with excellent water resistance, so even if this coating film absorbs a large amount of condensed water, or if it is painted in a bathroom or other area and gets wet with water, the coating film will not be damaged. have. Furthermore, since the coating composition of the present invention is water-based, there is little risk of fire, and there is no air pollution due to transpiration of large amounts of organic solvents.

(Example) Next, the present invention will be further explained with reference to Examples. In Examples, Comparative Examples, and Synthesis Examples, parts and % indicate parts by weight and % by weight, respectively.

Synthesis Example 1 35.6 parts of water and 2.8 parts of sodium nonylphenyl ether polyoxyethylene sulfate were charged into a polymerization vessel equipped with a stirrer, a reflux condenser, a dropping device, and a thermometer.
Raise the temperature to ℃. In a nitrogen stream, a monomer mixture of 19.8 parts of styrene, 32.2 parts of 2-ethylhexyl acrylate, 4.7 parts of methyl methacrylate, and 2.3 parts of acrylic acid, 5 parts of a 5% ammonium persulfate aqueous solution, and 5% hydrogen sulfite. 5 parts of aqueous sodium solution are added dropwise over 5 hours each.

Thereafter, a polymerization reaction is carried out at 75° C. for 2 hours, and after cooling to room temperature, the pH is adjusted to 8 using 25% aqueous ammonia.

Thus, the concentration is 49.6% and the viscosity is 80 cps (30°
An emulsion C) was obtained.

Synthesis Example 2 0.8 parts of sodium alkyl ether phosphate and 1.2 parts of alkyl phenyl ether polyoxyethylene were dissolved in 16 parts of water, and 16 parts of methyl methacrylate, 22 parts of ethyl acrylate, and 1 part of acrylic acid were dissolved in this solution. .7
of water and disperse thoroughly. 10% of this dispersion, 31 parts of water, 0 sodium alkyl ether phosphate
．． 8 parts and 1.2 parts of alkylphenyl ether polyoxyethylene are charged into a polymerization vessel equipped with a stirrer, a reflux condenser, a dropping device and a thermometer, and the temperature is raised to 80°C in a nitrogen stream. 0.5 parts of 5% ammonium persulfate aqueous solution and 5%
Add 0.5 parts of sodium bisulfite and conduct polymerization for 1 hour. Next, add 3 parts each of the 90% dispersion prepared above, 4.5 parts of 5% ammonium persulfate aqueous solution, and 4.5 parts of 5% sodium bisulfite aqueous solution. Drip over time. Thereafter, the temperature was raised to 85° C. and a polymerization reaction was carried out for 3 hours. After cooling to room temperature, the pH of the obtained emulsion was adjusted to 8.5 using 25% aqueous ammonia. The concentration of the emulsion at this time was 40.1%, and the viscosity was 460 cps (30
℃).

Example 1 104 parts of the emulsion of Synthesis Example 1, 16 parts of 20% ammonium carbonate aqueous solution, 6 parts of butyl cellosolve acetate, 1 part of dispersant, 1 part of wetting agent, 10 parts of titanium oxide, 120 parts of diatomaceous earth, 6 parts of 5% hydroxyethylcellulose aqueous solution , 1 part of antifoaming agent is thoroughly mixed using a disper mill. This paint was applied to the ceiling of the bathroom where dew condensation was frequently observed using a roller bagger, and the state of dew condensation was observed for 1fJ months, but no condensation was observed, and there were no abnormalities such as cracks or cracks on the painted surface. was not seen at all. Also, 7511
After applying the above paint to a 1x150nn iron plate with a roller to a thickness of 0°5nn, heat it at 20°C165.
%RH atmosphere for 7 days. Regarding this sample (1), the condition of the painted surface and water resistance and water absorption were observed.

The results are shown in Table 2.

<Examples 2 to 4> Paints were manufactured in the same manner as in Example 1 according to the compounding ratios shown in Table 1, and tested in the same manner as in Example 1. The results are shown in Table 2.

(Comparative Examples 1 and 2) Paints were manufactured in the same manner as in Example 1 according to the compounding ratios shown in Table 1, and tested in the same manner as in Example 1. The results are shown in Table 2.

(Evaluation method) 1. Occurrence of dew condensation in the bathroom Paint the ceiling of the bathroom where condensation was frequently observed with a roller bag and observe the occurrence of condensation for one month. Those in which no dew condensation was observed and those in which O1 condensation was observed are indicated by an x.

2. Condition of the painted surface The condition of the painted surface after the paint had dried was observed with the naked eye. Items with no cracks at all are ◎, items with some cracks are ○
, Those in which cracks were observed over the entire surface are indicated by an x.

3. Water resistance (20°C) The test piece was immersed in water at 20°C for 7 days, and the state of the coating film was observed with the naked eye. A case where no abnormality was observed is indicated by ◎, a case where the coating film was only softened is indicated by ○, and a case where the coating film began to dissolve into water is indicated by X.

4. Water resistance (80°C) The test piece was immersed in water at 80°C for 1 hour, and the condition of the coating film was observed with the naked eye. A case where no abnormality was observed is indicated by ◎, a case where the coating film was only softened is indicated by ○, and a case where the coating film began to dissolve into water is indicated by X.

5. A water absorption test piece was immersed in water at 20° C. for 3 hours, the amount of water absorbed was measured, and the evaluation was made by converting it into the amount of water absorbed when the paint was applied to an illumination thickness of 1M. The amount of water absorbed is 3009
If it is above, there is dew condensation prevention ability, and it is indicated by ○, and if the amount of water absorbed is less than 30, there is no dew condensation prevention ability, and ×
Indicated by

Claims (1)

[Claims] 0.1 to 30% by weight of ethylenically unsaturated carboxylic acid and 99.9% of a monomer copolymerizable with ethylenically unsaturated carboxylic acid.
A coating composition comprising a synthetic resin emulsion comprising ~70% by weight, a water-soluble complex comprising a divalent or higher metal salt and a volatile complexing agent, and a porous inorganic substance.