JPS5856590B2 - Paint for cement structures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Various paints are applied to cement structures such as GRC boards (glass fiber reinforced concrete boards), concrete, mortar, and asbestos boards for the purpose of protection and decoration.

Paints are rarely used in a single layer; they are usually used in multiple layers, such as primers, intermediate coats, and finishing materials.

One of the roles of the primer is to suppress the alkalinity of the concrete and to ensure that the overlying layer adheres to the concrete.

Conventionally, as such primers, -liquid temperature curing urethane paints and epoxy resin paints are known.

However, it has been found that GRC boards that have recently appeared have a high cement density and a dense surface, so these primers do not provide sufficient adhesion.

In particular, water resistance and humidity resistance were problematic, and the coating film blistered and blistered when exposed to moisture or moisture for a long period of time.

In addition, as a rooftop waterproofing method using paint films, urethane coatings and acrylic rubber emulsions are applied to the rooftops of buildings, but even though these paint films have perfect physical performance as waterproofing materials, The moisture inside the concrete slab may push it up and cause it to peel, causing blisters.

Once such blisters occur, they expand and contract repeatedly due to cycles of temperature rise and fall, and eventually the physical strength of the paint film deteriorates due to fatigue.

According to the present invention, these drawbacks are overcome by incorporating Portland cement and short fibers into conventional moisture-curing urethane or epoxy resin primers.

Therefore, when the paint of the present invention is used as a primer for cement structures, it improves water resistance and moisture resistance, and also fills pinholes in the base of cement structures, providing a sealing effect and preventing paint from being absorbed into the base. Improve unevenness.

Furthermore, the paint of the present invention has excellent adhesion to cement structures, especially GRC boards, and therefore, if the paint of the present invention is applied as a primer during rooftop waterproofing methods such as urethane distomer and acrylic rubber emulsion, it can be applied to the interior of concrete as described above. It is possible to effectively prevent blistering of the waterproof coating film due to the vapor pressure of water.

This was also confirmed by laboratory experiments.

That is, a conventional primer or the primer of the present invention is applied to a concrete panel, and then a Herarethane elastomer waterproofing material is applied and dried to create a test piece.This is fitted along the inner wall of a container containing water, and the outer periphery is When we sealed the gap with epoxy resin, heated the water inside to evaporate it, applied a coating film through the concrete spring, and applied steam pressure, the urethane elastomer waterproofing material using a conventional urethane primer did not swell after 5 minutes. (However, the primer of the paint of the present invention did not cause blistering even after 30 minutes.

The paint of the present invention can be used not only as a primer, but also as a base coat material and a base material for multilayer pattern spraying materials.

Normally, the construction of multilayer patterned spray material requires three steps, but if the paint of the present invention is used in the form of mastic, only two steps are required, which not only saves materials and labor, but also significantly shortens the construction period.

In that case, it is sufficient to simply form various patterns usually obtained with multi-layer pattern spray materials using a mastic roller, spray tile gun, mortar gun, etc. in a conventional manner, and then apply color coating thereon.

In this case, the thickness of the paint film can be made relatively thin, which prevents the internal stress (shrinkage strain, etc.) of the paint film from exceeding the adhesive strength and causing peeling, etc., which was observed in conventional Yuzu skin coating materials. .

As is well known, the liquid moisture-curing urethane primer is composed of a polyisocyanate component and a polyol component.
Its main component is a urethane prepolymer having a free incyanate group at the end, which is obtained by reacting the H ratio to an equivalent level or higher.

This urethane prepolymer absorbs moisture from the air, and the free incyanate groups react with the water to generate carbon dioxide gas, form urea bonds, and harden.

On the other hand, epoxy resins are obtained by condensation polymerization of epichlorohydrin and polyhydric phenol such as bisphenol A.

For curing, a curing agent such as an amine or an acid anhydride is used.

All of these are used after being diluted with an appropriate solvent to an appropriate viscosity.

The coating material of the present invention is a one-component moisture-curing urethane resin composition or an epoxy resin composition, as described above, mixed with Portland cement and short fibers.

For use as a primer, portland cement is not limited to white portland cement.

The short fibers can be organic fibers such as bulbs, inorganic fibers such as glass fibers, asbestos, rock wool, carbon fibers, etc., and the length may be as long as it does not interfere with spraying, but is preferably several nanometers or less. be.

The blending ratio of these depends on the type and concentration of the resin, and the type and shape of the short fibers, but generally 15 to 180 parts of Portland cement, preferably 20 to 100 parts, and 1 to 40 parts of the short fibers are added to 100 parts of the resin composition. parts, preferably 2 to 20 parts.

The coating material of the present invention may also appropriately contain inorganic fillers such as calcium carbonate and silica, and organic fillers such as cellulose derivatives and synthetic resin emulsion powder.

It is preferable that the Portland cement and the short fibers are mixed together with other powdered fillers in a predetermined proportion as necessary and supplied as a premix.

This premix and liquid resin composition are packaged separately,
At the time of construction, the resin liquid and filler premix may be mixed at a predetermined ratio and used on site.

Next, the present invention will be explained in detail by way of examples.

The middle part of the example is based on the weight.

Example 1 One-component moisture curing primer (Product name: Meiko Polo U Primer,
100 parts (manufactured by Isamu Paint ■), 40 parts of ordinary Portland cement, short pulp fibers (product name: KC Flock W-50)
) 8 parts, methylcellulose (trade name Tylose NH#40
00) and 50 parts of silica sand No. 8 were mixed therein and thoroughly stirred to obtain a slurry primer.

Example 2 One-component moisture-curing primer (trade name: Meiko Polo U Primer)
100 parts, 87 parts of ordinary Portland cement, 2 parts of asbestos short fibers (trade name: Resin Grade #244), 2 parts of ethyl cellulose (trade name: Cellosize QP4400H)
10.8 parts of special powder of silica sand were mixed therein and thoroughly stirred to obtain a slurry primer.

Example 3 Epoxy resin primer (Product name: Meiko Polo E Primer,
Made by Isamu Paint ■) 100 copies, Portland Seven Men) 6
0 parts, asbestos short fiber (trade name Chrysotile 7RF,
John Manville Co., Ltd.), 8 parts of polyvinyl acetate emulsion powder (trade name: Movinyl Powder MI, manufactured by Hoechst Synthesis), and 28 parts of calcium carbonate were mixed and stirred well to obtain a slurry primer.

The slurry primers of Examples 1 to 3 were applied to the GRC board and mortar board, respectively. /lri' spray, and then apply 300 f of acrylic urethane resin paint (product name: High Art #10 o o, manufactured by Isamu Paint ■) on top of it.
1/772” to prepare a test plate.

As Comparative Example 1, the Eporo E primer used in Example 3 alone was sprayed, and as Comparative Example 2, the Eporo U primer used in Example 1 alone was sprayed on a GRC board and a mortar board according to the example, and then sprayed on the mainland. Bayer) #100
A test plate was prepared by spraying 0 in the same manner.

Various tests were conducted on these test plates, and the results shown in the following table were obtained.

Test Results As is clear from the above test results, blisters occur in the coating film in the water resistance and moisture resistance tests in Comparative Examples 1 and 2 of the conventional primers, but no blisters are observed in Examples 1 to 3 of the primers of the present invention. .

Improvements were also seen in the ability to cover pinholes and the unevenness of paint suction onto the substrate, as well as improved adhesion.

Claims (1)

[Claims] 1- A paint for undercoating cement structures, which is made by blending Portland cement and short fibers with a liquid temperature air-curing urethane primer or an epoxy resin primer.