JPS61274773A - Method for applying high-concentration rubber asphalt emulsion - Google Patents

Abstract

PURPOSE:To enhance the working stability of an applicator by preventing the coagulation and gluing of a paint, in applying a high-concn. rubber asphalt emulsion by a brush or roller, by immersing the applicator in a specific dispersion prior to coating. CONSTITUTION:A dispersion is latex containing a rubber component such as styrene/butadiene rubber or natural rubber as a solid or an emulsion containing a synthetic resin such as an acrylic ester polymer, a vinyl acetate polymer or a copolymer of acrylic ester and vinyl acetate as a solid and generally has not only an O/W type composition with solid content of 35-55% but also property temporarily dispersing along with a high-concn. rubber asphalt emulsion to each other. After an applicator such as a brush or a roll has been immersed in said dispersion, said applicator is impregnated with the high-concn. rubber asphalt emulsion to make it possible to prevent the coagulation and gluing of said emulsion to the brush or the like due to the collapse of the emulsified state of said emulsion.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of coating a high-concentration rubber asphalt emulsion using a bristle or porous coating tool such as a brush, bristle roller, or felt roller. High-concentration rubber asphalt emulsion is an emulsion made by mixing bituminous material or a mixture of it with oil, etc., and latex, and is used as a waterproofing material for civil engineering and construction.

(Prior art) The composition of a high-concentration rubber asphalt emulsion has a composite form in which the latex portion is oil-in-water (0/W) type and the bituminous substance portion is water-in-oil type.
Generally, the solid content is 70-80% by weight,
Recently, those with a ratio of around 85% have been widely used. Rubber asphalt emulsions with a content of less than 80% have a relatively stable emulsification state, and there are almost no restrictions on coating.
In the case of 05 or more, phase inversion between the dispersed phase of the 07W type or W2O type and the dispersion medium is likely to occur, and especially at around 85%, the emulsified state can only be maintained within an extremely narrow range.

Therefore, the emulsification balance is sensitively affected by even a slight decrease in water content, resulting in instability and rapid coagulation.

(Problems to be Solved by the Invention) When applying a high-concentration rubber asphalt emulsion with a solid content of 80% or more using a painting tool such as a brush, bristle roller, or felt roller, a high-density comb is applied to the painting tool. When asphalt emulsion is impregnated, water, which is the dispersion medium, is adsorbed into the holes or holes of the coating tool.
In the impregnated area, the balance between the dispersed phase and the dispersion medium is locally disrupted, resulting in rapid solidification and adhesion to the surface, resulting in the performance required for brushes, including the content of the coating material, the surface area, and the flow within the pores. The adhesion due to the average rheological effect on the painted surface is lost, and these paint tools become unusable. When painting a low-concentration rubber asphalt emulsion, it is possible to prevent coagulation by soaking the painting tool in water before use to improve its adhesion, but in the case of a high-concentration rubber asphalt emulsion, it becomes bituminous when it comes into contact with moisture. A certain part of the oil phase separates and disperses into fine particles, which then aggregate and stick together again to form an agglomerate.

In this way, high 11 degree rubber asphalt emulsion can be painted using brushes, bristle rollers, and Fell! - Although impregnation-based painting tools such as rollers could not be used in the same way as with ordinary paints, ``high-density rubberized asphalt'' by the present applicant in Patent Application No. 16177.0 and Patent Registration No. 1280018 filed in 1982, ``Emulsion painting method'' was invented,
The basic problem mentioned above has been resolved. When applying a paint for aesthetic purposes, ultraviolet protection, etc. to a waterproof coating surface using the coating method described below, the solvents used in the above patented method are applied locally to the waterproof coating film at the initial stage of film formation. Taking into consideration the possibility that the remaining components may have some effect on the finish coating film, we have conducted various studies and found that the dispersion described in the claims of the present invention meets the above-mentioned objective.

(Means for solving the problem) In other words, dispersions are made of latex, acrylic ester, vinyl acetate, and their co-products, whose solid content is rubber components such as SDR (styrene butadiene rubber), chloroprene rubber, and natural rubber. An emulsion whose solid content is a synthetic resin such as a polymer, generally O/W with a solid content of 35 to 55%.
It has a characteristic of temporarily dispersing with the rubber asphalt emulsion. As emulsifiers for these dispersions, there are various ionic surfactants, namely anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants, and the dispersions used in the present invention include fatty acid salts, Anionic activators such as higher alcohol sulfate ester salts, dibasic fatty acid ester sulfonates, and nonionic activators such as polyoxyethylene alkyl ethers and sorbitan alkyl esters are suitable. The reason for this is that the emulsification mechanism of high-concentration rubber asphalt emulsions is based on anionic surfactants such as fatty acid salts, resinates, higher alcohol sulfate ester salts, alkylbenzene sulfonates, and nonionic surfactants such as polyoxyethylene alkyl ethers. This is because these agents are often used alone or in combination, and belong to the same ionic system as the above-mentioned dispersion.

(Function) For the above reasons, the dispersion applied to the present invention is a brush that applies high concentration comb asphalt emulsion,
It has been found that this method improves the work stability of rollers, etc. That is, when a brush or wool roller is impregnated with the dispersion and immediately impregnated with a high-concentration rubber asphalt emulsion, each emulsion is colloidally dispersed and stabilized without damaging the dispersed phase of the predetermined polymer particles. maintain the rheological effect.

When these dispersions are diluted with water, they still maintain some effectiveness, but when the ratio of water is extremely large, the bituminous component that is the oil phase separates into sticky particles and sticks to the brush, resulting in extremely In a short period of time, the brush loses its impregnation and flowability and becomes unusable.

During application, as the high-concentration rubber asphalt emulsion is repeatedly impregnated and spread, the dispersion contained in the brush is replaced by the rubber asphalt emulsion and soon disappears, but the new rubber asphalt emulsion that is successively incorporated is already The rubber asphalt emulsion contained in the brush in a stable form prevents dryout and provides fluidity through phase dispersion, thereby preventing sticking and coagulation. As mentioned above, the high-concentration rubber asphalt emulsion contained in the pores or in the coating tools such as brushes and rollers by the dispersion is a method following the coating method using a non-polar solvent described in the above-mentioned Patent No. 1280018. Since the coagulation obstruction caused by dryout is removed, continuous coating is possible, and a waterproof coating film of high-concentration rubber asphalt emulsion that meets the purpose of the present invention can be formed.

Example: A varnish brush and a bristle roller for painting are impregnated with styrene-butadiene latex (Chugai Shoko ■Product name: One Coat Mix) as a dispersion, and then immediately mixed with a high-concentration rubber asphalt emulsion (Japan Synthetic Rubber ■Product name: Hull Coat) , solid content 85%), the mixed portion of the dispersion and rubber asphalt emulsion was rubbed off on a wooden board, and the rubber asphalt emulsion was again impregnated and applied to the surface to be coated. No solidification or stagnation was observed during the coating operation, which lasted several hours, and continuous operation was possible. In addition, by the same operation, in addition to the styrene-butadiene latex described in t, an acrylic acid ester emulsion (trade name: Vinacryl 4001, manufactured by Dainippon Ink Chemical Industry Co., Ltd.) and a vinyl acetate emulsion (trade name, Bond C2, manufactured by Conicy) using an anionic or nonionic surfactant were prepared. ), ethylene/vinyl acetate copolymer emulsion (product name 0 manufactured by Kuraray)
M4000) was used as a dispersion, and similar effects were confirmed.

Claims (2)

[Claims] (1) When applying a high-concentration rubber asphalt emulsion with a solid content of 80% or more by weight using a bristle or porous coating tool such as a brush, bristle roller, or felt roller, apply synthetic resin immediately before using the coating tool. Alternatively, the high concentration rubber asphalt emulsion and the dispersion in the impregnated area are temporarily dispersed and assimilated into each other by immersing the synthetic rubber in a dispersion having a solid content and then impregnating it with the high concentration rubber asphalt emulsion. A coating method for high-concentration rubber asphalt emulsion designed to prevent the collapse of the emulsified state due to rapid dehydration and the resulting coagulation and sticking. (2) The coating method according to claim 1, wherein the dispersion is a rubber latex and resin emulsion specified in JISA6203 "Polymer dispersion for mixing with cement".