KR101459806B1 - Self-leveling composition - Google Patents

Abstract

The present invention is a self-leveling composition comprising a high-viscosity cellulose ether and a low-viscosity cellulose ether in combination with a self-leveling composition containing gypsum as a main ingredient and no aggregate. According to the present invention, it is possible to provide a self-leveling composition having a long pot life at the time of forming a horizontal plane, excellent fluidity and surface smoothness (little wrinkles or cracks), and high surface strength.

Description

Self-leveling composition {SELF-LEVELING COMPOSITION}

The present invention relates to a self-leveling composition used as a flooring flooring or the like.

The self-leveling material (SL material) is widely used as a flooring finishing material because it naturally flows only by kneading with water and flowing to the floor, forming a horizontal surface and curing. Gypsum-based, cement-based, and the like are currently supplied to the SL material. Prior art documents related to such SL materials include the following.

Patent Document 1 discloses a cement and / or gypsum fine aggregate, a water reducing agent (fluidizing agent or dispersant), a defoaming agent, a condensation retarder, a condensation promoter, ), A water-soluble cellulose ether having a residual amount of 5 mass% or less, and water as essential components. However, this self-leveling composition needs to increase the viscosity in order to prevent the aggregate from being separated, which causes the fluidity of the slurry to deteriorate and the workability to deteriorate. Further, when the thickness is 5 mm or less at the time of shedding, the surface smoothness of the formed horizontal surface tends to be easily affected by the unevenness under the floor, and even when the thickness is made to be as thick as 50 mm, there is a risk of sedimentation of aggregate. Thus, this self-leveling composition is undesirable.

In addition, when the aggregate is not blended with the self-leveling material, flow loss (decrease in flow value due to aging) due to hydration and aggregation of reactants (such as cement or gypsum) is accelerated, There is a problem in that it can not be taken sufficiently.

Patent Document 1: JP-A-2006-56763

Problems to be solved by the invention

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a self-leveling composition which has a long mid-viscosity time when forming a horizontal plane, excellent fluidity and surface smoothness (without wrinkles or cracks) do.

[MEANS FOR SOLVING THE PROBLEMS]

The inventors of the present invention have conducted intensive studies in order to achieve the above object. As a result, it has been found that, by blending a cellulose ether having a high viscosity and a low viscosity into a specific self-leveling composition, a self-leveling composition having a long working time and excellent fluidity and surface smoothness and a horizontal surface having a high surface hardness can be obtained. The present invention has been accomplished on the basis of this finding.

That is, the present invention provides a self-leveling composition comprising a high-viscosity cellulose ether and a low-viscosity cellulose ether blended with a self-leveling composition based on gypsum and free of aggregates. The self-leveling composition preferably further comprises a chelating agent. By including the chelating agent, it becomes a self-leveling composition which gives a horizontal surface with further improved surface smoothness.

[Effects of the Invention]

According to the present invention, by mixing a high viscosity cellulose ether and a low viscosity cellulose ether in a gypsum-based self-leveling composition containing no aggregate, it is possible to obtain an excellent flowability at the time of forming a horizontal plane, It is possible to provide a self-leveling composition which is excellent in the surface smoothness of the formed horizontal surface and gives a high surface hardness to the obtained horizontal surface. In addition, by further compounding the chelating agent, it is possible to provide a self-leveling composition which can prevent the occurrence of cracks on the surface and give a horizontal surface with further improved surface smoothness.

BEST MODE FOR CARRYING OUT THE INVENTION [

The present invention will now be described in more detail.

In the self-leveling composition of the present invention, powdery gypsum is used as a main component. Examples of the gypsum include α-type half gypsum, II-type anhydrous gypsum, and β-type semi-gypsum.

The self-leveling composition of the present invention does not include aggregates. If the self-leveling composition contains aggregates, it is necessary to make the slurry have a certain viscosity or more above a certain level in order to prevent settling of aggregates. When water is mixed with the self-leveling composition at the time of forming a floor level, And has a reduced fluidity. Therefore, when the slurry flows down to 5 mm or less in particular, the slurry tends to be affected by the unevenness under the floor, and the surface smoothness deteriorates, and even if the slurry flows thickly to about 50 mm, the aggregate may settle.

In the self-leveling composition of the present invention, at least two kinds of cellulose ethers are blended. Specific examples of the cellulose ether include methylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and hydroxyethylethylcellulose.

Examples of the cellulose ether include a high viscosity and a low viscosity. In the present invention, a high viscosity cellulose ether and a low viscosity cellulose ether are used in combination. The high-viscosity cellulose ether preferably has a viscosity of 40,000 to 100,000 mPa · s as measured by a Brookfield viscometer at 20 ° C and 20 rpm, when the solution is a 2% by mass aqueous solution. In terms of the molecular weight, it has a weight average molecular weight (molar molecular weight) of 5 × 10 ⁵ to 7 × 10 ⁵ (g / mol). One of the low-viscosity cellulose ethers preferably has a viscosity of 200 to 1,000 mPa · s as measured by a Brookfield viscometer at 20 ° C. and 20 rpm when the solution is a 2% by mass aqueous solution. In terms of molecular weight, it has a weight average molecular weight (molar molecular weight) of 1 × 10 ⁵ to 2 × 10 ⁵ (g / mol).

The sum (A + B) of the blending amount (A) of the high viscosity cellulose ether and the blending amount (B) of the low viscosity cellulose ether per 100 parts by mass of the gypsum is preferably 0.02 to 0.7 part by mass. The blending amounts (A, B) of the high-viscosity cellulose ether and low-viscosity cellulose ether are preferably 0.01 to 0.6 parts by mass per 100 parts by mass of gypsum, respectively. When the amount of the cellulose ether combined with the high viscosity and the low viscosity is less than 0.02 parts by mass per 100 parts by mass of gypsum, sufficient self-leveling composition can not be obtained and sufficient bleeding occurs, The strength of the horizontal surface after curing of the composition is not uniform. Further, the bleeding may cause bleeding (efflorescene) or cracks. On the other hand, if the amount of the gypsum used per 100 parts by mass of the gypsum is more than 0.7 part by mass, the viscosity of the obtained slurry is too high, and the fluidity of the slurry becomes insufficient and the self-leveling property which is an important characteristic of the self-leveling composition is impaired. The too high viscosity may cause wrinkles on the resulting horizontal surface, which may damage the appearance or cause the strength to be lowered. (A) to the blending amount (A) of the low viscosity cellulose ether to the blending amount (B) of the low viscosity cellulose ether is preferably 1: 0.02 to 1:50, more preferably 1: 0.1 to 1:10.

In the self-leveling composition of the present invention, it is possible to reduce the generation of a film on the surface when the floor surface is formed. In order to prevent the occurrence of cracks, it is preferable to further formulate a chelating agent. Specific examples of the chelating agent include ethylenediamine tetraacetic acid, diethylenetriamine 5-acetic acid, hydroxyethylethylenediamine 3-acetic acid, nitrilo triacetic acid, and dihydroxyethylglycine. Among these, diethylenetriamine 5-acetic acid, which is effective for retarding the coagulation of the aqueous slurry of the self-leveling composition of the present invention, is preferred.

The blending amount of the chelating agent is preferably 0.02 to 0.5 parts by mass per 100 parts by mass of gypsum. When the blending amount of the chelating agent is less than 0.02 parts by mass, the effect of preventing the formation of a film on the surface can not be sufficiently exhibited. On the other hand, if the blending amount is more than 0.5 parts by mass, the production cost is increased by using a large amount of the chelating agent, which is not preferable.

In the self-leveling composition of the present invention, one or more of cement, a water reducing agent (fluidizing agent or dispersing agent), a defoaming agent, a coagulation retarder, a condensation promoter, an inorganic growth agent, a synthetic resin and the like may be appropriately added.

Examples of the cement include ordinary Portland cement, HIGH-EARLY-STRENGTH CEMENT, MODERATE HEAT PORTLAND CEMENT, PORTLAND BLAST-FURNACE Cement, Cement, silica cement, fly ash cement, alumina cement, and jet cement (REGULATED SET CEMENT). The cement is blended for improving the water resistance of the flooring flooring material to be formed, but the blending amount thereof is preferably 5 to 50 parts by mass per 100 parts by mass of gypsum.

The water reducing agent (fluidizing agent or dispersing agent) is not particularly limited as long as it is generally commercially available. Usually, a water reducing agent such as polycarboxylic acid type, melamine type or naphthalene type can be used. The blending amount of the water reducing agent is preferably 0.01 to 5 parts by mass per 100 parts by mass of gypsum. In the case of the self-leveling composition, a water reducing agent can be added because it is necessary to obtain excellent flowability with as little water (water amount) as possible. However, if the amount is too small, the effect can not be obtained. On the other hand, It may be connected to a decrease in the strength of the horizontal surface to be formed, or may cause whitening.

Examples of the defoaming agent include polyether-based, silicone-based, alcohol-based, mineral oil-based, vegetable oil-based, and nonionic surfactants.

Examples of the coagulation retarder include citrates such as sodium citrate, borates such as acacic acid salt, acetic acid salt, malic acid salt and borax, sucrose, hexametaphosphate, ethylenediamine tetraacetate, starch and proteolytic products. The blending amount of the coagulation retarding agent may be set to such an extent that the coagulation retarding function can be exerted as necessary. Concretely, it is preferable to blend 0.005 to 1 part by mass of a coagulation retarder per 100 parts by mass of gypsum.

Examples of the condensation accelerator include soluble calcium salts such as calcium chloride, calcium nitrite, calcium nitrate, calcium bromide and calcium iodide, chlorides such as iron chloride and magnesium chloride, and sulfates such as potassium sulfate, potassium hydroxide, sodium hydroxide, carbonate, thiosulfate , Formic acid, formic acid salts such as calcium formate, and the like. As the inorganic growth material, talc, calcium carbonate, or the like can be used.

The synthetic resin is preferably in the form of a powder, and is preferably a resin such as a vinyl acetate resin, a versatate vinyl resin, a vinyl acetate-versatate vinyl copolymer, an acrylic resin, a vinyl acetate-acrylic acid copolymer, a vinyl acetate-versatate vinyl- A styrene-butadiene copolymer, and the like. The synthetic resin is compounded in order to increase the surface hardness of the flooring bottom material to be formed, but the blending amount thereof is preferably 0.05 to 1 part by mass per 100 parts by mass of gypsum.

The self-leveling composition of the present invention can be formed into a flooring flooring by adding water and thoroughly mixing it, then pouring the obtained slurry into the bottom of the floor, spreading, leaving, curing and drying have. Examples of the bottom surface of the floor include mortars, cement, wood, tiles made of plastic or metal such as sheet, ceramic and stainless steel.

The blending amount of water is preferably 20 to 50 parts by mass per 100 parts by mass of gypsum. If the blending amount of water is too small, sufficient fluidity can not be obtained, and the obtained slurry may be difficult to lead to leading to deteriorate workability. Conversely, if the amount is too large, the obtained flooring bottom material will have a decreased strength. Therefore, it is not preferable to blend water out of the above range.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

<Materials Used>

Gypsum: α type semi-plaster

Cement: ordinary Portland cement

Water reducing agent: polycarboxylic acid series

Coagulation retardant: Sodium citrate (reagent)

Chelating agent: diethylenetriamine 5-acetic acid (DTPA, reagent)

Condensation accelerators: Sulfates (reagents)

Cellulose ether: High-viscosity cellulose ether (viscosity 50,000 mPa 占 퐏)

                    The intermediate cellulose ether (viscosity: 4,000 mPa 占 퐏)

                    Low viscosity cellulose ether (viscosity 300 mPa s)

(The viscosity is a value measured by the above-mentioned measuring method and measuring conditions).

Antifoaming agent: polyether-based

Synthetic resin: vinyl acetate-acrylic acid copolymer

Aggregate: Silica (particle diameter 0.05 ~ 0.8mm)

[Example 1]

As shown in Table 1, 0.05 parts by mass of high-viscosity cellulose ether per 100 parts by mass of gypsum and 0.12 parts by mass of low-viscosity cellulose ether were combined to prepare a cement, a water reducer, a coagulation retarder, a condensation accelerator, a synthetic resin, (1.0 to 1.5 parts by mass as a total of 100 parts by mass of gypsum) were mixed to obtain a powdery self-leveling composition. Then, 45 parts by mass of water was added per 100 parts by mass of gypsum to a mixing bowl as shown in Table 1, and then the self-leveling composition obtained above was slowly added with stirring. After completion of the addition, Using a testing machine instrument specified in 8.1 of JIS R 5201, kneaded for 3 minutes and mixed to obtain a slurry-like self-leveling composition.

[Example 2]

As shown in Table 1, a self-leveling composition was obtained in the same manner as in Example 1, except that 0.08 part by mass of a chelating agent was added per 100 parts by mass of gypsum.

[Example 3]

As shown in Table 1, a self-leveling composition was obtained in the same manner as in Example 1, except that the blending amount of the high-viscosity cellulose ether was set to 0.1 parts by mass and the blending amount of the low-viscosity cellulose ether was set to 0.03 parts by mass.

[Example 4]

As shown in Table 1, a self-leveling composition was obtained in the same manner as in Example 2 except that the blending amount of the high-viscosity cellulose ether was 0.04 parts by mass and the blending amount of the low-viscosity cellulose ether was 0.3 parts by mass.

[Comparative Example 1]

As shown in Table 2, a self-leveling composition was obtained in the same manner as in Example 1, except that the blending amount of the high-viscosity cellulose ether was 0.11 parts by mass and the low-viscosity cellulose ether was not blended.

[Comparative Example 2]

As shown in Table 2, a self-leveling composition was obtained in the same manner as in Example 1, except that fresh starch cellulose ether was blended in an amount of 0.18 parts by mass per 100 parts by mass of gypsum, and high-viscosity cellulose ether and low-viscosity cellulose ether were not blended .

[Comparative Example 3]

As shown in Table 2, a self-leveling composition was obtained in the same manner as in Example 1, except that the blending amount of the low viscosity cellulose ether was 0.5 part by mass and the high viscosity cellulose ether was not blended.

[Comparative Example 4]

As shown in Table 2, in Example 1 (1), except that 0.08 parts by mass of fresh cellulose ether was added per 100 parts by mass of gypsum, the content of the high-viscosity cellulose ether was changed to 0.03 parts by mass, and low viscosity cellulose ether was not blended, A self-leveling composition was obtained.

[Comparative Example 5]

As shown in Table 2, in the same manner as in Example 1 except that the high-viscosity cellulose ether was not blended with 0.1 part by mass of 100 parts by mass of gypsum and the low-viscosity cellulose ether was added in an amount of 0.1 part by mass, A self-leveling composition was obtained.

[Comparative Example 6]

As shown in Table 2, 50 parts by mass of fresh aggregate was added to 100 parts by mass of gypsum, the amount of the high-viscosity cellulose ether was changed to 0.1 part by mass, the amount of low-viscosity cellulose ether was changed to 0.1 part by mass, A self-leveling composition was obtained in the same manner as in Example 1, except that the amount thereof was 0.09 parts by mass.

The slurry-like self-leveling compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 6 were evaluated by performing each of the following tests. The results of the tests for each of the self-leveling compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 6 and their evaluation criteria (appropriate values) are also shown in Table 1 and Table 2, respectively.

[Flow value]

It was measured according to the JASS 15M-103 standard specification of the Japanese architectural building construction.

[Viscosity]

The viscosity of each slurry was measured with a specified amount of slurry in a special cup of the measuring instrument by using a viscometer BISCO Tester VT-04E {(trade name, manufactured by RON Corporation, shear rate: 4 sec-1) Respectively.

[Flow velocity]

Each slurry was poured into a slurry feeding portion (100 mm in height × 50 mm in length × 100 mm in width) of an acrylic measuring instrument having a horizontal height of 100 mm × a total length of 500 mm × a width of 100 mm. After a lapse of 7 minutes from the start of the injection, the door made of an acrylic plate forming one side of the slurry inlet was instantaneously lifted and the time until the slurry reached the end of the measuring instrument was measured to calculate the flow rate by the following equation .

Flow rate (mm / s) = slurry moving distance (450 mm) / measuring time (s)

[Working time]

The housekeeping time was measured in the same manner as the above flow measurement according to JASS 15M-103. A predetermined amount of each slurry was poured into a vertical pipe made of vinyl chloride and allowed to stand. After the elapse of the predetermined time, the pipe was pulled up to measure the diameters of the slurry spreading in the horizontal direction in two orthogonal directions after the spread of the slurry was stopped, and the average value was obtained by calculation. And the time that the average value can be secured at 190 mm or more was defined as pot life time.

[Surface hardness]

Each slurry was poured into a box-shaped container having a height of 20 mm, a length of 100 mm and a width of 100 mm, and allowed to stand at room temperature for 48 hours to be cured. The cured product was placed in a drier at 40 ° C, dried until constant weight, The cured product was taken out from the drier, and the surface hardness was measured by pressing a rubber hardness meter (TYPE D ', trade name, manufactured by TECLOCK) on the surface of the cured product.

[Surface smoothness (surface condition: presence or absence of wrinkles or cracks)]

Each slurry was poured into a plastic container having a length of 30 cm x 50 cm width so that the slurry had a thickness of 10 mm. After 30 minutes had elapsed, about 250 cc of slurry was further flowed into the center of the container. The surface smoothness of the cured product was checked periodically until after 4 weeks of tactile and visual sighting.

Surface smoothness (wrinkles and cracks) was judged according to the following evaluation criteria.

<Wrinkles>

A: 1,500 cm ² , 0.5 mm or more in width, 5 mm or more in length, and the number of wrinkles is 0

B: per 1,500 cm ² , number of wrinkles of 0.5 mm or more in length and 5 mm or more in length

C: 1,500 cm ² or more, a width of 0.5 mm or more, and a length of 5 mm or more, 2 to 5 wrinkles

D: 1,500 cm ² or more, a width of 0.5 mm or more, a number of wrinkles of 5 mm or more in length, 6 or more

A is particularly good, B is good, C is poor and D is very poor.

<Crack>

A: 1,500 cm ² , the number of cracks is 0

B: 1,500 per ² cm, number of cracks 1

C: per 1,500 cm ² , number of cracks ² to 5

D: More than 6 cracks per 1,500 cm ²

A is particularly good, B is good, C is poor and D is very poor.

In the self-leveling compositions of Examples 1 to 4, the evaluation results on all of the above test items were particularly good or good. That is, as shown in Examples 1 to 4, when the high-viscosity cellulose ether and the low-viscosity cellulose ether are blended in the gypsum and the aggregate is not blended, the fluidity at the time of forming the horizontal plane is excellent, It is possible to obtain a self-leveling composition which is excellent in surface smoothness and can provide a horizontal surface with a high surface hardness.

In addition, the self-leveling compositions of Examples 2 and 4 are better than those of the self-leveling compositions of Examples 1 and 3 (as evidenced by the absence of cracks). That is, the self-leveling compositions of Examples 2 and 4 are improved in surface smoothness by incorporating a chelating agent. On the other hand, in the self-leveling compositions of Comparative Examples 1 and 2, the flow rate was low, the pave time was short and the surface smoothness was bad, the self-leveling composition of Comparative Example 3 had low surface hardness, 4, the self-leveling composition of Comparative Example 5 had poor surface smoothness, and the self-leveling composition of Comparative Example 6 had a low flow rate, short pot life, and poor surface smoothness, , Low flow rate, low surface hardness, and poor surface smoothness.

[Table 1]

[Table 2]

According to the present invention, it is possible to provide a self-leveling composition which has a long usable time for forming a horizontal plane, excellent fluidity and surface smoothness (almost no wrinkles or cracks), and gives a horizontal plane with high surface strength.

Claims (5)

The present invention provides a gypsum-based self-leveling composition containing no aggregate, wherein the high-viscosity cellulose ether and the low-viscosity cellulose ether are blended with a Brookfield viscometer at 20 ° C Viscosity of 40,000 to 100,000 mPa · s as measured at 20 rpm and the low viscosity cellulose ether as a 2% by mass aqueous solution has a viscosity of 200 to 1,000 mPa · s as measured by a Brookfield viscometer at 20 ° C. and 20 rpm Of the self-leveling composition. delete The cellulose acylate film according to claim 1, wherein the sum (A + B) of the blending amount (A) of the high viscosity cellulose ether and the blending amount (B) of the low viscosity cellulose ether per 100 parts by mass of the gypsum is 0.02 to 0.7 part by mass, Wherein the ratio of the blend amount (A) of the high-viscosity cellulose ether to the blend amount (B) of the ether is A: B = 1: 0.02 to 1: 50. The self-leveling composition according to any one of claims 1 to 3, further comprising a chelating agent. The self-leveling composition according to claim 4, wherein the amount of the chelating agent is 0.02 to 0.5 parts by mass per 100 parts by mass of gypsum.