JPS632918B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention uses a stretchy rubber or rubber-asphalt based aqueous emulsion that is compatible with concrete and has waterproof properties, in order to prevent not only erosion caused by water penetrating from the surface of concrete, but also erosion and deterioration caused by acids, salts, etc. An anti-corrosion/water-proof laminate with a two-layer structure in which a primer layer is formed on the concrete surface using the above primer layer, and a corrosion-resistant layer of unsaturated polyester resin or epoxy resin containing a scale-like filler with excellent corrosion resistance is provided in this primer layer. Regarding. Until now, emulsions based on synthetic resins such as ethylene-vinyl acetate copolymer resins and acrylic esters, rubbers such as styrene-butadiene rubber, or rubber-asphalt emulsions have been used to protect concrete surfaces, mainly to provide waterproof properties. It is being used. These waterproofing materials generally have poor resistance to acids such as hydrochloric acid, sulfuric acid, and nitric acid, and when the acids that permeate through the waterproofing material reach the concrete, they significantly erode and destroy the concrete, creating a major problem in terms of corrosion protection. It was becoming. Preventing concrete erosion is a particular issue in workplaces that handle acids, such as pickling processes in the steel industry, textile dyeing and bleaching processes, paper and pulp processing processes, fertilizer processes such as ammonium sulfate, and salt electrolysis processes. Moreover, when a material with anticorrosion performance against acids and salts is destroyed on the concrete surface, the adhesion between the anticorrosion material and the concrete is relatively poor, especially when the surface of the concrete is wet. The coating material inhibits interfacial adhesion due to its hydrophobic nature. In actual applications, this is a problem because the concrete is often wet. In order to solve these problems all at once, the present invention coats the concrete surface with a rubber or rubber-asphalt water-based emulsion that has an elongation of 100% or more as measured by JIS K6301, and then coats the concrete surface with a water-based emulsion of rubber or rubber-asphalt. A corrosion-resistant layer made of unsaturated polyester resin or epoxy resin whose corrosion resistance has been improved by a scale-like filler is provided on top, so that the characteristics of the upper and lower layers can complement each other and exhibit a mutually beneficial effect. If the elongation is less than 100%, the effectiveness of covering cracks in concrete over time is low. The scaly fillers used in the present invention include glass flakes and graphite flakes, and the thickness ranges from several microns to more than ten microns and the size ranges from 10 to 10 microns.
325 mesh is suitable. Further, the amount added is relatively preferably 10 to 70 parts by weight per 100 parts by weight of the synthetic resin. By containing the scale-like filler, the gas and liquid permeability is suppressed to about 1/20 of that without the filler, and the anticorrosion performance is significantly improved. Examples of the present invention are as follows: Example 1 A water-based chloroprene rubber emulsion was applied to the surface of concrete to form a waterproof coating film of approximately 100μ, and then an anticorrosion material having the composition shown in Table 1 was applied using a spray machine. Apply to a thickness of 200μ, leave for 3 hours, then spray paint to a thickness of 200μ. The elongation of the coating film was 750%.

[Table] Compared to conventional products, the products of the present invention have excellent chemical resistance as shown in Table 2, and as shown in Table 3, they also have excellent adhesion to the two-layer concrete of the present invention.

【table】

[Table] Example 2 A water-based emulsion containing 30% styrene-butadiene rubber was applied as a primer to the surface of a concrete mortar measuring 50 mm (height) x 300 mm (length) x 300 mm (width) and left for 7 days. and dry it.
A dry film of 100μ was formed. Next, on the same concrete mortar surface,
Two-component polyurethane resin paint (reacted with polypropylene glycol and TDI, and 1,4-butanediol with a ratio of isocyanate to hydroxyl groups)
It was prepared by adding it to 1.0. ) and 30℃, 7
It was left to dry for several days to form a dry film of 100 μm.
Regarding the above sample (coating film), ASTM C-290
-67, freeze-thaw tests were conducted. The test machine was Yashima Seisakusho, model CH-P413-3, -
Hair racks were generated on the concrete asphalt for 2 hours from 1 cycle to 400 cycles at 18 DEG C. to +20 DEG C./cycle, and the state of cracks in the coating film on the surface of the concrete asphalt at that time is shown in Table 4.

[Table] The elongation was measured.
As shown in Table 4, the coating film of the present invention, which has a high elongation, follows cracks in the concrete substrate well over time, and the coating protection effect is remarkable. As described above, the corrosion-resistant material of the present invention has a high usability effect against highly corrosive acids and salts for concrete, and
It facilitates the maintenance and management of tanks, floors, etc., and provides a protective coating that protects against cracks in concrete over time, greatly contributing to extending the life of the concrete.

Claims (1)

[Claims] 1 Form a primer layer on the concrete surface using rubber or rubber-asphalt water-based emulsion that has an elongation of 100% or more as measured by JIS K6301, and add glass flakes or graphite flakes alone as a scaly filler on top of the primer layer. Or an anticorrosive/waterproof laminate having a two-layer structure coated with a corrosion-resistant material made by blending 10 to 70 parts by weight of a mixture thereof with 100 parts by weight of an unsaturated polyester resin or epoxy resin.