JPH05295338A - Aqueous emulsion adhesive - Google Patents

Abstract

PURPOSE:To provide an aqueous emulsion adhesive to increase the adhesion of a vinyl chloride-based foam applied on the inner surface of a pottery tank for storing water for water closet. CONSTITUTION:This adhesive is prepared by mixing an aminated silane compound and an antifoaming agent with an aqueous emulsion of vinyl acetate polymer known in the prior art. Thereby, the water resistance is enhanced and the adhesiveness between the pottery surface of a water storage tank and a vinyl chloride foam is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ceramics, and more particularly to an adhesive used when a vinyl chloride foam is applied to the inner surface of a cistern.

[0002]

[Problems of the prior art] As a measure for preventing dew condensation on a ceramic water storage tank (cistern) for flush toilets, a vinyl chloride foam layer has been provided. The means for forming the vinyl chloride foam layer includes a method of adhering a preformed vinyl chloride foam layer to the inner surface of the cistern and a method of applying the vinyl chloride foam sol to the inner surface of the cistern and heating it. Methods of forming a foamed layer are known. In recent years, however, as the trend toward higher-grade housing has increased, the cistern was also box-shaped, but the shape has diversified and it is becoming more and more preferred that there be no corners. In the case of a cistern having such a shape, it is required to improve the technique of providing a vinyl chloride foam layer on the inner surface.

On the other hand, the inner surface of the cistern and the vinyl chloride foam layer are adhered to each other using an aqueous emulsion adhesive of vinyl acetate polymer type. However, since vinyl acetate polymer-based aqueous emulsion adhesives have the drawback of poor water resistance, vinyl chloride-based foaming sol is applied to the inner surface of the cistern to form a foam layer. Peeling of the foam layer tends to occur.

[0004]

Therefore, in the present invention, it has been found that by adding a small amount of an amino group-containing silane compound to an aqueous emulsion of the vinyl acetate polymer, the adhesiveness in the normal state can be improved and the water resistance can be remarkably improved. ..

[0005]

DETAILED DESCRIPTION OF THE INVENTION An adhesive, an aqueous emulsion of vinyl acetate polymer, is applied to the inner surface of a cistern before application of a vinyl chloride foamable sol. Aqueous emulsions of vinyl acetate polymer include vinyl acetate-
Aqueous emulsions of ethylene copolymers have also been used. As a coating method, it is convenient to use a spray method in addition to a brush coating method, but to use a spray method if the shape of the stan is not a simple box type. Once the aqueous emulsion has been applied, it is dried by holding it at a temperature of about 150 ° C. for about 30 minutes in a drying oven. Next, a vinyl chloride foaming sol is applied to a thickness of about 2 mm, and it is usually heated at about 150 ° C. for 10 minutes in a hot air circulation oven.
Then, the temperature is raised to about 210 ° C. for about 7 minutes for foaming.

The vinyl acetate polymer aqueous emulsion used in the present invention is Esdyne 6040 (Sekisui Chemical Co., Ltd.), SP-210 (Konishi Co., Ltd.) or BE.
It is commercially available under the names such as -800 (Chuo Rika Kogyo Co., Ltd.). This has a solid content of about 50-60%,
It is convenient to use by diluting with about 7 to 12 times water. In the present invention, an amino group-containing silane compound is added thereto in an amount of 0.2 to 5% by weight based on the total composition. Since the amino group-containing compound is basic (about pH 10.5), and the pH of the vinyl acetate polymer-based aqueous emulsion is 4 to 6, most of which is 5 to 5.5, the stability of the aqueous emulsion is improved by adding the silane compound. May decrease, which may make application, particularly spray application, difficult. In such a case, a small amount of surfactant may be added. As the surfactant, it is preferable to add a nonionic surfactant having a large HLB value, for example, a polyoxyethylene sorbitan fatty acid ester, a polyoxyethylene alkyl ether, or a polyoxyethylene alkyl aryl ether having an HLB value of about 15 or more.
The amount of surfactant used is 100% solid content of the aqueous emulsion.
It is 0.5 to 2 parts by weight per part by weight, and it is not preferable to use a large amount because the water resistance is lowered.

Although any amino group-containing silane compound may be used in the present invention, N- (βaminoethyl) -γ-aminopropyltrimethoxysilane is the most effective and preferred because it is easily available. Such a silane compound is manufactured by Shin-Etsu Silicone “KBM-60
3 ”or“ TSL-8340 ”manufactured by Toshiba Silicone. When the amount of the amino group-containing silane compound used is 0.2% by weight or less, the adhesiveness is not improved, and when it exceeds 5% by weight, the foaming of the vinyl chloride foaming sol becomes abnormal, which is not preferable. In addition, there is a case where a remarkable foaming phenomenon occurs due to back pressure during spray application, which makes uniform application difficult. In such a case, it is advisable to add about 0.05 to 1% by weight of an antifoaming agent. The defoaming agent of is preferable. Further, it goes without saying that dyes, fragrances and the like can be added if necessary.

Next, the present invention will be described more concretely with reference to Examples and Comparative Examples. Compounding parts by weight of vinyl chloride foaming sol % G-22 (Nippon Zeon) 100 51 DOP 85 43.4 PVC stabilizer, FL-64 (Ba-Zn system, Asahi Denka Co., Ltd.) 42 Cell modifier, KH-300A -10 1 0.5 Foaming agent, AZ-H (Otsuka Chemical) 6 3.1

Preparation of Adhesives The corresponding amounts (parts by weight) of the respective components shown in Table 1 were mixed in the following order with a small stirrer (manufactured by Shinto Kagaku, Three One Motor) (about 30 seconds for each addition). Materials used Amino group-containing silane compound (manufactured by Shin-Etsu Chemical: KBM-60
3, pH 10.5), antifoaming agent (manufactured by Shin-Etsu Chemical: KM-7)
1), surfactant (polyoxyethylene lauryl ether-based nonionic surfactant, manufactured by Kao: Emulgen 120,
HLB 15.3) and vinyl acetate-ethylene copolymer aqueous emulsion (Sekisui Chemical Co., Ltd .: Esdyne 6040,
pH 5.5, solid content concentration 56%) [Order of addition] Water, KBM-603, KM-71, Emulgen 120, Esdyne 6040. However, Emulgen 12
0 is diluted with an equal weight of water before use.

Evaluation method (1) Long-term heating adhesiveness A water-based adhesive is spray-coated on the inner surface (matte surface) of a cistern of arbitrary size, and heated for a long time in a hot air circulation furnace (15
After 0 ° C for 0.5 to 48 hours), a vinyl chloride foaming sol is applied (thickness: about 2 mm). Temporarily, two-stage heating foaming {(150 ° C × 10 minutes) + (210 ° C × 7 minutes)} was applied in a hot air circulation furnace, and long-term heat adhesion was evaluated every 0.5, 1, 24 and 48 hours. did.

(2) Water-resistant adhesiveness The foamed test piece obtained in the above (1) is immersed in water (25 ° C. × 3).
~ 6 months), the water-resistant adhesive property after the elapse was evaluated. However (1)
The long time heating at 150 ° C. for 48 hours was performed.

(3) Stability of adhesive with time The adjusted adhesive is left in a constant temperature and humidity chamber (25 ° C. × 60% R
H × 30 days) The tests (1) and (2) above were performed. However
The long-time heating in (1) was 150 ° C. × 24 hours.
The water immersion in (2) was performed at 25 ° C. for 3 months.

(4) Adhesiveness Evaluation Method The cistern / foam layer of each of the samples obtained in (1), (2) and (3) above is cut with a sharp knife to make the adhesion difficult and easy. It was judged.

(5) Surface state of foamed body The surface foamed state of the Cistern foam obtained under each of the above conditions was visually observed.

(6) Spray coatability Spray gun (made by IWATA: W-61 type, nozzle diameter 1 m
At m and air pressure of 3 kgf / cm ² ), the difficulty and easiness of application when each adhesive listed in Table 1 was applied to the inner surface of the cistern was evaluated. [Evaluation criteria] (1) Uniformity (related to nozzle clogging due to emulsion aggregation, viscosity increase, etc.) (2) foaming

[0016]

[Table 1]

[0017]

[Table 2]

From the results shown in Table 2, the water-resistant adhesiveness was inferior only with the adhesive composed of the vinyl acetate polymer-based aqueous emulsion.
Water infiltrates into the interface between the cistern and the foam, and the original purpose of providing a foam layer on the inside of the cistern to prevent condensation on the surface of the stan is not satisfied, and only the amino group-containing silane compound is used. However, it was found that the adhesiveness against heating by heat for a long time was inferior and it was unsuitable as the above-mentioned measure for preventing dew condensation. However, according to the adhesive of the present invention, it is possible to carry out adhesion having excellent water resistance and long-term heating stability, and spray application is also possible.

Claims (1)

[Claims] 1. An adhesive between a vinyl chloride type foam comprising an aqueous emulsion of a vinyl acetate polymer containing an silane compound having an amino group and an antifoaming agent and a ceramic.