JPS59146960A - Self levelling floor composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to cementitious self-leveling flooring compositions.

Traditionally, cement mortar, which is a mixture of cement, sand, and water, has been used to finish floors such as concrete slabs and balconies, but in order to obtain the necessary strength, it is necessary to reduce the amount of water added to the cement. There must be. In other words, the water-cement ratio must be reduced.

Therefore, conventional cement mortar has a drawback of poor fluidity. Adding a large amount of water to improve fluidity not only reduces the strength of the cured product but also causes cracks to form.

On the other hand, some gypsum-based flooring acids have self-leveling properties that allow you to create a smooth floor surface just by pouring them, but they have the disadvantage of poor water resistance after hardening, and cement-based cell 7 The advent of lehering floor compositions was desired.

The present inventors focused on the fact that casein is effective in self-leveling properties in this type of composition, and conducted various studies.

However, a composition obtained by simply adding casein, sand, and water to Portland cement and kneading it has good leveling properties, but has the disadvantage that it takes a long time to set. As a result of various studies, it was found that the presence of slaked lime significantly shortened the setting time.

The present inventors believe that this slaked lime also has another effect of increasing the solubility of casein.

And by further using fly ash,
Fluidity was further improved.

However, cracks frequently occurred after curing, and as a result of various studies on this issue, we found that by using a lime-gypsum-based expansive material, sand of a specific particle size, redispersible powdered resin, and a water reducing agent together, fluidity was improved. It was possible to prevent the occurrence of cracks without damaging the surface, and the smoothness of the surface was further improved.

That is, the present invention includes 100 parts by weight of cement, 5 to 60 parts by weight of lime-gypsum-based expansive material, 0.5 to 5 parts by weight of casein, 0.5 to 5 parts by weight of slaked lime, and 2 to 2 parts by weight of fly ash.
The main ingredients are 0 parts by weight, 1 to 60 parts by weight of a redispersible powder resin, 0.1 to 5 parts by weight of a water reducing agent, and 50 to 400 parts by weight of an inorganic filler with a particle size range of 5 to 300 microns. This self-leveling bed composition is characterized in that it contains conventional additives such as antifoaming agents and antifoaming agents.

The cement used in the present invention includes ordinary Portland cement, white Portland cement, early strength Portland cement, and alumina cement.

Casein is 0.5 to 100 parts by weight (cemen)
5 parts by weight is suitable. If it is less than 0.5 parts by weight, the fluidity will be poor, and if it exceeds 5 parts by weight, the setting time will be longer.
Strength decreases.

The amount of slaked lime used is 0.5 per 100 cement layers.
~5 parts by weight is preferred. If it is less than 0.5 parts by weight, shortening of the setting time cannot be expected, and if it exceeds 5 parts by weight, the strength will decrease.

The fly ash used in the present invention has a specific surface area of 2500
A powder of ~4000 om/9 is preferable, and its use i is suitably 2 to 20 parts by weight per 100 parts by weight of cement. Less than 2 layers contributes little to liquidity, and 20%
If the amount exceeds parts by weight, there is a tendency for strength to decrease.

Next, the lime-gypsum expanding material, the redispersible powder resin, the water reducing agent, and the inorganic filler with a particle size range of 5 to 600 microns work synergistically to prevent the occurrence of cracks after curing. It is something.

Onoda Expan (manufactured by Onoda Cement) and Sax (manufactured by Sumitomo Cement) can be used as lime-gypsum-based expansive materials, and the amount used is 5 to 5 parts by weight per 100 parts by weight of cement.
60 parts by weight is suitable. If it is less than 5 parts by weight, the crack prevention effect cannot be exhibited, and if it exceeds 30* parts, the surface smoothness will deteriorate.

Redispersible powder resins include vinyl acetate homopolymer emulsion, ethylene, vinyl chloride, acrylic ester, methacrylic ester, Beoba (vinyl ester of branched saturated carboxylic acid of shell chemical glue), acrylic acid, methacrylic acid. , a copolymer emulsion of vinyl acetate and one or more selected vinyl M monomers such as crotonic acid, acrylamide, acrylonitrile, and styrene; an acrylic acid ester copolymer emulsion;
A redispersible powder resin obtained by spray-drying a methacrylic acid ester copolymer emulsion or a copolymer emulsion of an acrylic acid ester or a methacrylic acid ester and a vinyl monomer can be effectively used.

The advantage of redispersible powder resins for the purpose of the present invention is that when they encounter water, they redisperse back to their original emulsion and are mixed with cement to provide a crack-preventing effect. Another advantage over the emulsion itself is that since it is in powder form, it can be used as a ready-made product by simply adding water and kneading, and even if the redispersible powder resin encounters water, it can be completely removed immediately. It does not return to the original emulsion, but the number 10 in the process
Powder particles of ~100 microns fill the gaps between cement and aggregate, helping to improve strength and waterproofness.

The amount used is 1 to 60 parts per 100 parts of cement.
Parts by weight are appropriate. If it is less than 1% by weight, the crack prevention effect cannot be exhibited, and if it exceeds 60 parts by weight, it tends to impair leveling properties, which is not preferable.

Examples of water reducing agents include lignin sulfonate, sulfonate of melamine-formalin condensate, and polyoxyethylene alkylphenol ether. The appropriate amount to be used is 0.1 to 5 parts by weight per 100 parts by weight of cement. If the amount is less than 0.1 parts by weight, no water reduction effect will be observed, and if it exceeds 5 parts by weight, no improvement in the effect will be observed.

As an inorganic filler with a particle size range of 5 to 600 microns,
Calcium carbonate silica sand, silica stone powder, dolomite, etc., and those having a particle size range of 5 to 600 microns are preferred.

The amount used is 50 to 4 parts by weight per 100 parts by weight of cement.
00 parts by weight is appropriate; if it is less than 50 parts by weight, the effect of preventing crack generation cannot be improved, and if it exceeds 400 parts by weight, fluidity will be inhibited, so it is not preferable. Ethyl ethyl cellulose and the like can be suitably used.

Antifoaming agents include vegetable oils such as castor oil, mineral oils such as liquid paraffin, fatty acids such as stearic acid, alcohols such as oleyl alcohol, fatty acid esters such as ethylene glycol, amides, amines, phosphate esters,
A carrier made of inorganic powder such as clay or calcium carbonate that absorbs silicone or the like, or a metal soap can be used.

Next, the present invention will be explained by showing examples, comparative examples, and test results.

Example 1 20 parts by weight of alumina cement, 80 parts by weight of ordinary Portland cement, 5 parts by weight of lime-gypsum expansive material (Sakus/manufactured by Sumitomo Cement) 2 parts by weight of casein, 3 parts by weight of slaked lime, 5 parts by weight of fly ash, ethylene - 15 parts by weight of a redispersible powder resin obtained by spray drying a vinyl acetate copolymer emulsion, 0.3 parts by weight of aqueous melamine-formalin resin sulfonate, particle size range from 5 microns to 600 microns.
This is a self-leveling bed composition in which 80 parts by weight of silica sand powder with a particle size distribution close to normal distribution in microns is uniformly mixed.

The composition is as shown in Table 1.0 Example 2 and Example 3 A self-leveling bed composition in which the components of the composition shown in Table 1 were uniformly mixed in the same manner as in Example 1.

Comparative Examples 1 to 6 As shown in Table 1, 100 parts by weight of ordinary Portland cement, lime-gypsum expansive material, casein, slaked lime, fly ash, redispersible powder resin,
These compositions were mixed and prepared without using any water reducing agents.

Comparative Examples 7 to 11 As shown in Table 1, 100 parts by weight of ordinary Portland cement is used for lime-gypsum-based expansive material, casein, slaked lime, fly ash, and redispersible powder resin. This is a composition prepared by mixing using the above amount.

The flow value, presence or absence of cracks, surface smoothness, and compressive strength were measured for the compositions of Comparative Test Examples and Comparative Examples. The results are shown in Table 1.

Test Method Flow Value After placing a hard PVC pipe of 50 mm x 40 mm on a glass plate and pouring the prepared self-leveling material into it, the hard PVC pipe formwork was immediately removed and the spread of the material was examined. According to this method, if it is 150 mm or more, it is determined that the fluidity is excellent.

Cracks: 250 mm x 70 mm x 3 mm: A formwork was prepared by installing a 10 mm high weir at one end of the slate board in the longitudinal direction, and providing side plates connecting the weir and the other end on both longitudinal edges. The formwork was arranged so that the top of the weir of the formwork and the other end of the floor plate were horizontal, and the material was poured into it, and the presence or absence of cracks was examined after -1 week.

Evaluation criteria ◎: No cracks observed at all.

○: Some small cracks (hair cracks) are observed.

Δ: Many fine cracks (hair cracks) are observed.

×: Many large cracks are observed.

Surface Smoothness The material was poured into a 100 mm x 100 mm x 10 mm iron mold, and after - days, the smoothness of the surface was observed with the naked eye.

Evaluation criteria ◎: Very smooth.

○: Slightly lacking in smoothness.

△: There is considerable unevenness.

×: There is a marked unevenness.

After pouring the material into a formwork with a compressive strength of 40 mm x 40 mm x 80 mm and curing it under standard conditions for a predetermined number of days (6 days, 28 days), 1. Measured according to T Engineering SR5201.

Claims (1)

[Claims] 1 Cement: 100 parts by weight Lime, gypsum-based expansive material: 5 to 60 parts by weight Casein 0.5 to 5 parts by weight Slaked lime
0.5-5 parts by weight fly ash
2 to 20 parts by weight powdered resin
1 to 30 parts by weight Water reducing agent 0.1 to 5 parts by weight Particle size range 5 to 600 microns Main ingredient: 50 to 400 parts by weight of inorganic filler, and contains ordinary additives such as water retention agents and antifoaming agents. A self-leveling floor composition characterized by: