JPH0240632B2 - SEMENTOSHITSUHYOMENNOHIFUKUHOHO - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for coating cement surfaces, and particularly to a method suitable for coloring and protecting cement surfaces such as roof tiles, slate boards, concrete decorative boards, and the like.

Conventionally, for example, when coloring the surface of thick slate, it is cured for about three weeks after press molding, and then the surface is baked with solvent-based or emulsion-based acrylic resin, or two-component acrylic-urethane resin paint. Alternatively, immediately after press molding, a slurry containing synthetic resin emulsion, cement, and aggregate was sprayed for curing, and the next day the surface was spray-painted with solvent-based synthetic resin paint or emulsion resin paint. However, in the former case, the color vehicle of the paint is an organic polymeric material, which has the disadvantage of long-term weather resistance, and the manufacturing process involves separating molding and painting, resulting in high product costs.

In the latter method, the slurry is spray-painted immediately after molding, and then a top coat is applied to the surface after curing.During curing, discoloration occurs due to the formation of voids due to water evaporation inside the slurry material and the whitening phenomenon caused by alkali in the cementum. It turned white and required many manufacturing steps, making it expensive. In this way, conventionally, even if you apply a solvent-based top coat on top of water,
It was common knowledge that adhesion was difficult and a complete coating could not be formed. Next, in JP-A-56-46712, in an inorganic slurry formulation, the ratio of water to cement was too high, such as 1:1, and the acrylic emulsion resin sprayed next contained 60% water. An example is shown. In the case of a thick slate base material with low water absorption, such a method using a large amount of water requires evaporation of water from the surface, and the voids in the slurry where water has evaporated cause effroescence (whitening phenomenon). Maneki,
Then sprayed acrylic emulsion resin (40%
Solution), the film forming temperature is a problem, and during curing, it is difficult to set the temperature and humidity conditions and the curing start time due to the relationship with the base material, which requires a large amount of cost, and it is difficult to produce a good product. It was difficult.

The present invention was made in order to overcome the deficiencies of known technologies, and in the production of thick slate, etc., press compression molding is performed to dehydrate the slurry in such a way that the moisture in the slurry transfers to the slate base material, and the water is immediately removed. , coating the cementitious surface with a reduced cement ratio,
Immediately after, apply solvent-based resin paint and cure.
It was discovered that a thick slate with a high-quality surface coating can be made, and the present invention was developed.

That is, in the present invention, mortar is pressure-molded to form a base material, a slurry is applied to the surface of the base material, a solvent-based synthetic resin paint is applied immediately after that, and the surface of the cementitious product is coated by curing. In doing so, the slurry contains 3 to 15 parts by weight of a resin solid content of synthetic resin emulsion or emulsion powder, 0.1 to 5 parts by weight of a cement dispersant, and, if necessary, up to 10 parts by weight of a pigment, based on 100 parts by weight of cement. The base material is kneaded with enough water to form a flowable slurry, and the base material is molded to such an extent that it can absorb at least part of the water in the slurry when it is applied. The coating thickness of the slurry is 100~
1000 microns, and the curing is 15~15 μm for the first stage.
2-4 hours at 30℃, second stage at 40-50℃, humidity 80-80℃
It is characterized by being carried out in two stages of 10 to 30 hours at 95RH.

According to the present invention, since the surface finish can be completed immediately after molding the base material, it is possible to provide a method for manufacturing thick slate of good quality under extremely easy conditions both in the process and in curing. can do.

Hereinafter, the present invention will be specifically explained with reference to Examples.

First, mix mortar with a sand/cement ratio of 2.5:1 to 1.7:1 and mix it with an appropriate amount of water, then put it inside the mold of a high-pressure press and apply a pressure of 50 to 100 kg/ ^cm2 over the entire surface of the product to dehydrate it. , molded into a state capable of absorbing water to form a base material. On the surface of the base material coming out of the molding machine,
Resin solid content of synthetic resin emulsion or emulsion powder is 3 to 100 parts by weight of cement.
15 parts by weight, 0.1 to 5 parts by weight of cement dispersant, if required, add up to 10 parts by weight of pigment, add coatable water and knead to make a slurry with a thickness of 100 to 5 parts by weight.
Paint to 1000 microns. Immediately after that, a solvent-based acrylic resin paint is sprayed to a thickness of 10 to 50 microns, and the moisture inside the slurry is absorbed into the slate base material, and at the same time the acrylic resin topcoat adheres to it. After manufacturing, keep at a temperature of 15° to 30°C for 2 to 4 hours, wait for the solvent of the acrylic resin top coat to evaporate and the coating film to stabilize, and then store at a temperature of 40° to 50°C and humidity of 80% to 95°C.
After curing for 10 to 30 hours at a low temperature of 100%, we were able to produce thick decorative slate with a high gloss and good quality.

Next, the slurry composition and other reasons for limitations regarding the method of the present invention will be explained in detail.

The resin solid content of synthetic resin emulsion or emulsion powder is 3 parts by weight for 100 parts by weight of cement.
If the amount is less than 1 part by weight, the coating film will not have the necessary strength and cracks will occur. If it exceeds 15 parts by weight, the coating film will be soft and easily scratched due to the high resin content, making it unsuitable for commercialization.

Cement dispersants are expensive, but if the amount is less than 0.1 part by weight, good fluidity of the slurry cannot be obtained and the amount of water required for kneading increases. Moreover, if it exceeds 5 parts by weight, it will take time for the initial stabilization of the slurry coating layer after coating, and curing and other post-treatment steps will be delayed.

Generally, 3 to 5 parts by weight of the pigment is sufficient for coloring, and up to 10 parts by weight is allowed for deepening the color. Therefore, even if it is added in an amount exceeding 10 parts by weight, there is little effect on coloring, and on the contrary, extra water is required for dispersion, which adversely affects the hardening and strength of the slurry. The addition of this pigment is optional; for example, when the base material is white cement, it is not necessary to add it.

Water is added in an amount of 30 to 50 parts by weight, preferably 35 to 42 parts by weight, based on 100 parts by weight of cement. If it is less than 30 parts by weight, uniform fluidity of the slurry cannot be obtained, and if it exceeds 50 parts by weight, "sagging" or floating water may occur in the coating film. In order to be able to carry out the top coating immediately after applying the slurry, the amount is preferably 35 to 42 parts by weight.

Suitably, the thickness of the slurry applied to the base material is 100 to 1000 microns. If the thickness is less than 100 microns, the required strength cannot be obtained, and especially if the base material (rice material) is dry, too much water in the slurry coating will be absorbed into the base material, causing cracks. On the other hand, if the thickness exceeds 1000 microns, the moisture in the coating exceeds the limit that can be absorbed by the base material, it takes time to stabilize, and cracks are more likely to occur as described above.

Products coated with slurry and topcoat are kept at temperatures of 15-30° C. for 2-4 hours after manufacture for a first stage of curing. This is to avoid temperature rise and stabilize the coating state until the initial setting time of the cement in the slurry layer is completed. At this time, if the temperature is lower than 15° C., curing takes time and there is a risk that efflorescence may occur as described above.

Since the first stage of curing stabilizes the solvent evaporation and the coating film of the top coat, the second stage involves normal curing at a temperature of 40 to 50°C and a humidity of 80 to 90% for 10 to 30 hours.

As described above, according to the present invention, the slurry adheres to the mortar base material, and the top coat that adheres to the slurry helps to cure the slurry material over a long period of time, allowing it to completely harden, and after the top coat wears out, it is difficult to apply during spray painting. There is a small amount of moisture inside the slurry,
In addition, since acrylic resin is mixed in, it is waterproof and does not cause whitening, and is abrasion resistant and does not cause discoloration due to whitening of the inorganic pigments used (effroessence). The surface coating material with a thickness of 100 to 1000 microns and the press-molded base material have low water absorption, high strength, and can withstand long-term use compared to conventional products, and reduce costs by streamlining the manufacturing process. be able to.

Claims (1)

[Claims] 1 Pressure mold mortar to form a base material, apply slurry to its surface, immediately apply a solvent-based synthetic resin paint, and then cure to cover the surface of the cementitious product. The slurry is a flowable slurry containing 100 parts by weight of cement, 3 to 15 parts by weight of resin solids of synthetic resin emulsion or emulsion powder, 0.1 to 5 parts by weight of cement dispersant, and 10 parts by weight or less of pigment as necessary. The base material is dehydrated during molding to the extent that it can absorb at least part of the water in the slurry when the slurry is applied. The coating thickness of the slurry is 100 to 1000 microns, and the curing is performed at 15 to 30°C for 2 to 4 hours in the first stage, and at 40 to 50°C and 80 to 95 RH for 10 hours in the second stage. ~30
A method for coating a cementum surface, characterized in that the method is carried out in two time stages.