JP4596130B2 - Self-leveling composition - Google Patents

Description

  The present invention is a hydraulic composition having excellent self-smoothness used for the surface finish of concrete structures and the upper part of fabric foundations, and more specifically, excellent in fluidity and self-smoothness, and particularly excellent in the surface condition after curing. The present invention relates to a self-leveling composition (hereinafter abbreviated as “SL material”).

The SL material has been popularized mainly by the plastering flooring method for construction and the leveler of the upper part of the fabric foundation in order to save labor and improve the efficiency of the surface finishing work of concrete structures using its self-smoothness. In recent years, the use of SL material has been proposed as an alternative to plastering work for surface finishing in precast concrete production. As SL materials used for these underfloor construction methods and other construction methods, gypsum, cement and the like are known. For example, as a cement-based SL material, JP-A-56-84358 (Patent Document 1), JP-A-58-120554 (Patent Document 2), JP-A-60-86065 (Patent Document 3). ), JP-A- 62-138349 (Patent Document 4), JP-A- 9-268046 (Patent Document 5), JP-A-6-136922 (Patent Document 6), JP-A-2002-356357 ( JP-A-52-66527 (Patent Document 8), JP-A-53-14733 (Patent Document 9), and JP-A-2003-174527 have been proposed in Patent Document 7) and the like. No. 53-124534 (Patent Document 10), Japanese Patent Laid-Open No. 53-124535 (Patent Document 11), and the like. Among these, although there is a description about the surface property after curing as intended by the present invention, it is possible to suppress foaming by removing the entrained air at the time of kneading with an antifoaming agent, and it is excellent. It is to obtain a good surface property. However, such a method alone still does not prevent the generation of pinholes on the surface after curing, and blistering occurs due to bubbles in the pinholes both in appearance and in the case of construction thereon. However, a satisfactory quality SL material has not been obtained.

JP-A-56-84358 JP 58-120554 A JP-A-60-86065 JP-A-62-138349 Japanese Patent Laid-Open No. 9-268046 JP-A-6-136922 JP 2002-356357 A JP 52-66527 A JP-A-53-14733 JP-A-53-124534 Japanese Patent Laid-Open No. 53-124535

  The present invention provides an SL material suitable as a surface finishing SL material that prevents the occurrence of pinholes after curing derived from those that cannot be removed with this antifoaming agent, and is excellent in appearance and construction. With the goal.

  As a result of intensive studies to achieve the above object, the present inventors have found that the remaining amount of sieve having a sieve number 100 (mesh size 150 μm) described in the 14th revised Japanese Pharmacopoeia B1061 as cellulose ether is 5% by mass or less. It has been found that by using a self-leveling composition using a certain water-soluble cellulose ether, the generation of pinholes on the surface after curing caused by factors other than bubbles that can be removed by an antifoaming agent can be suppressed.

  That is, the self-leveling composition contains cement and / or gypsum, fine aggregate, water reducing agent (fluidizer or dispersant), antifoaming agent, setting retarder, setting accelerator, and Water-soluble cellulose ether is blended for the purpose of preventing material separation such as bleeding.

  However, unlike other water-soluble polymers, water-soluble cellulose ether has a particle structure in which fibrous substances are intertwined. Dissolves and becomes gel-like particles. Once gelled, water does not penetrate well into the interior and slows dissolution. In the case of a normal mortar composition, a water reducing agent (fluidizing agent or dispersant) is not required, and the amount of water is about 25% by mass or less of the entire system, so that the kneaded product itself is relatively hard, Dissolution proceeds rapidly by rubbing particles such as aggregates with water-soluble cellulose ether once in a gel state. However, in the case of the SL material, the amount of water is 20 to 45% by mass, but since the water reducing agent (fluidizing agent or dispersing agent) is used in a relatively large amount, the viscosity of the kneaded material becomes very low, The effect of promoting dissolution due to friction between the water-soluble cellulose ether in the form of gel and aggregate particles cannot be expected, and the gel remains even after kneading. Furthermore, the gel-like water-soluble cellulose ether particles having air bubbles float near the surface due to the low viscosity of the SL material, and dry with hardening, and the portion where the gel-like water-soluble cellulose is present becomes a film. Causes the generation of holes.

  Pinholes generated in this way cannot be removed by a method that removes bubbles entrained during SL material kneading with an antifoaming agent, and is difficult unless water-soluble cellulose ether that fundamentally dissolves in a short time is used. I came to the conclusion that

  Therefore, as a result of various studies, the inventor uses a water-soluble cellulose ether having a sieve remaining amount of sieve number 100 (mesh size 150 μm) described in the 14th revised Japanese Pharmacopoeia B1061 of 5% by mass or less. It has been found that the dissolution of the gel-like water-soluble cellulose ether generated during kneading is accelerated, the water is drawn on the surface of the SL material, and the dissolution is completed before the drying starts, and these problems can be solved. The present invention has been completed.

Therefore, the present invention provides the following SL materials.
[I] Cement and / or gypsum, fine aggregate, inorganic filler, water reducing agent (fluidizer or dispersant), antifoaming agent, setting retarder, setting accelerator, water-soluble cellulose ether, and water are essential components A self-leveling composition, wherein the amount of cement and / or gypsum used is 15 to 85 parts by mass with respect to a total amount of 100 parts by mass of cement, gypsum, fine aggregate and inorganic filler, The amount of fine aggregate and inorganic filler used is 15 to 85 parts by mass, the amount of water-soluble cellulose ether used is 0.02 to 0.5% by mass, and the amount of water reducing agent used is 0.01 to 5% by mass. The amount of antifoaming agent used is 0.1 to 5% by mass, the amount of setting retarder used is 0.001 to 5% by mass, the amount of setting accelerator used is 0.005 to 3% by mass, the addition amount is 20 to 45% by weight of the total composition, as the cellulose ethers, the 4 amendments sieve remaining Japanese Pharmacopoeia B1061 sieve No. 100 according (eye open 150 [mu] m) is, self-leveling compositions, characterized in that using a surface-treated non water-soluble cellulose ether is not more than 5 wt% .
[II] The self-leveling composition according to [I], which exhibits a viscosity of 0.1 to 30 Pa · s when measured at 20 rpm at 10 rpm.
[III] The self-leveling composition according to [I] or [II], wherein the water-soluble cellulose ether is selected from methylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and hydroxyethylethylcellulose.

  According to the present invention, it is possible to suppress the generation of pinholes derived from undissolved cellulose ether other than air bubbles that can be removed with an antifoaming agent that is involved during kneading, and not only is aesthetically pleasing, but also has a finishing process thereon. It is possible to obtain a cured body of a self-leveling composition that does not cause blistering or the like even when it is subjected to.

  Specific examples of the water-soluble cellulose ether used in the self-leveling composition of the present invention include methylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and hydroxyethylethylcellulose. Among them, the remaining amount of sieve No. 100 (mesh size 150 μm) described in the 14th revised Japanese Pharmacopoeia B1061 is 5 mass% or less, preferably 3.5 mass% or less, more preferably 1.5 mass% or less. Use things. In this case, such a water-soluble cellulose ether having a sieve remaining amount of 5% by mass or less is passed through a pulverizer such as a ball mill or a vibration mill, for example, with a sieve number 100 (mesh size 150 μm) described in the 14th revised Japanese Pharmacopoeia B1061. It is obtained by, for example, sieving for 10 minutes with a sieving machine which simultaneously gives vibration and rotational motion of 130 to 165 per minute with an equivalent sieve.

  The viscosity of the water-soluble cellulose ether is usually 5 ° C., 100,000 mPa · s at 20 rpm, preferably 10 to 90,000 mPa · s at 20 ° C., when a 2 mass% aqueous solution is obtained at 20 ° C. More preferably 15 to 80,000 mPa · s is used. If the viscosity is lower than 5 mPa · s, the material separation resistance may be insufficient. If the viscosity is higher than 100,000 mPa · s, the SL material is too viscous and the required self-leveling property cannot be obtained. Or the surface may be wrinkled, the appearance may be impaired, or the viscosity may be excessively increased so that defoaming with the antifoaming agent cannot be performed.

  In the present invention, the water-soluble cellulose ether as a thickener is excellent in material separation resistance with a small amount of addition, since it suppresses material separation to a sufficient level while maintaining high fluidity.

  The amount of water-soluble cellulose ether used is 0.02 to 0.5% by mass, preferably 0.03 to 0.45, based on 100 parts by mass of the total mass of cement, gypsum, fine aggregate, and inorganic extender described later. % By mass, more preferably 0.04 to 0.4% by mass. When the amount used is less than 0.02% by mass, sufficient material separation resistance is not recognized, bleeding occurs, aggregates settle and the strength after hardening does not become uniform, and white May cause glare and cracks. On the other hand, if the amount added is too high, the viscosity is too strong, so that the fluidity is poor and the self-leveling property, which is an important characteristic of the SL material, is not only impaired, but the surface is wrinkled and the appearance is deteriorated or the viscosity is increased. If the amount is too large, defoaming by the antifoaming agent cannot be performed, and there may be a case where bubble blowing occurs or strength is reduced.

  The SL material of the present invention additionally contains cement and / or gypsum, fine aggregate, water reducing agent (fluidizer or dispersant), antifoaming agent, setting retarder, setting accelerator, water, and further if necessary. Inorganic fillers, polymer emulsions and the like can be blended.

  As the cement, various types of cement such as ordinary Portland cement, early-strength Portland cement, medium-heated Portland cement, blast furnace cement, silica cement, fly ash cement, alumina cement, jet cement and the like can be used. The total mass of cement, gypsum, fine aggregate, and inorganic extender is expressed as 100 parts by mass, and other admixtures are expressed as mass% based on 100 parts by mass).

  The amount of the cement used is 15 to 85 parts by mass, preferably 20 to 80 parts by mass, and more preferably 25 to 75 parts by mass. When the amount used is less than 15 parts by mass, there may be a problem that curing is significantly delayed or not cured. On the other hand, if the amount used is more than 85 parts by mass, drying shrinkage or self-shrinkage may occur, resulting in inconveniences such as occurrence of cracks on the cured surface.

  In addition, a part or all of the amount may be replaced with gypsum instead of cement, and as gypsum, anhydrous gypsum, hemihydrate gypsum, or the like is preferably used, and dihydrate gypsum or the like is also used in some cases.

  As the fine aggregate, river sand, mountain sand, sea sand, crushed sand, etc., which are used for general ready-mixed concrete production or plastering fine aggregate, are suitable. The particle size is 5 mm or less, preferably 2 mm or less, more preferably 1 mm or less. The amount of fine aggregate used is 15 to 85 parts by mass, preferably 20 to 80 parts by mass, and more preferably 25 to 75 parts by mass. When the amount of fine aggregate used is more than 85 parts by mass, there are few hydraulic substances, and curing may be significantly delayed or may not be cured. On the other hand, when the amount used is less than 15 parts by mass, the amount of the hydraulic substance is excessive, and cracks due to drying shrinkage may occur.

  A part of the fine aggregate may be replaced with an inorganic filler, and as the inorganic filler, fly ash, blast furnace slag, talc, calcium carbonate, marble powder (limestone powder) or the like is used.

  The water reducing agent (fluidizer or dispersant) is not particularly limited as long as it is generally commercially available. Usually, polycarboxylic acid-based, melamine-based, naphthalene-based water reducing agents and the like are used. The amount used is preferably about 0.01 to 5% by mass, and the optimum amount is determined depending on the type and brand. In the case of SL material, it is used because it is necessary to obtain excellent fluidity with as little water as possible. However, if the amount used is too small, the effect cannot be obtained, and conversely if it is too much, materials such as bleeding and aggregate sedimentation are used. This may cause separation, leading to a decrease in strength, and may cause white bloom.

  As the antifoaming agent, polyether-based, silicone-based, alcohol-based, mineral oil-based, vegetable oil-based, nonionic surfactants and the like are used. As for the usage-amount of these antifoamers, 0.1-5 mass% is preferable. If the amount used is less than 0.1% by mass, the entrained air will not be defoamed and the surface properties may be impaired, and the strength may be reduced. On the other hand, even if the amount used exceeds 5% by mass, the defoaming effect may not be improved.

  In most cases, a set retarder and a set accelerator are used in combination. This is to control the setting time of the cement, and after a few tens of minutes of use time, it quickly develops strength and becomes a means for enabling light walking on the next day. As the setting retarder, organic acids such as gluconic acid, citric acid and malic acid or salts thereof such as sodium, potassium, calcium, magnesium, ammonium and triethanolamine, or oxycarboxylic acids such as organic acids, glucose and fructose Saccharides such as galactose, saccharose, xylose, abitose, repose, oligosaccharide, dextran, boric acid and the like. As for the usage-amount, 0.001-5 mass% is preferable normally.

  On the other hand, as a set accelerator, soluble calcium salts such as calcium chloride, calcium nitrite, calcium nitrate, calcium bromide and calcium iodide, chlorides such as iron chloride and magnesium chloride, sulfate, potassium hydroxide, Examples include formic acid salts such as sodium hydroxide, carbonate, thiosulfate, formic acid and calcium formate. These combinations are combinations of cement or gypsum to be used, a set retarder, and a set accelerator, and the optimum range may be determined. Usually, in order to obtain a sufficient set acceleration effect, 0.005 to 3% by mass Used in the range of

  The polymer emulsion may be liquid or re-emulsified powder. Generally, when the SL material is manufactured in a plant, the liquid polymer emulsion is used and kneaded on site etc. Many of the commercially available powder type polymer emulsions are used. Polymer emulsions include vinyl acetate resin, versatic acid vinyl resin, vinyl acetate-vinyl versatic acid copolymer, acrylic resin, vinyl acetate-acrylic acid copolymer, vinyl acetate-vinyl versatic acid-acrylic acid ester copolymer And styrene-butadiene copolymer. These are added to improve the durability and the like of the SL material, and improve the surface hardness and the like. The addition amount of the polymer emulsion is desirably 1 to 15% by mass, and if the addition amount is less than 1% by mass, the required durability may not be obtained. If the addition amount is more than 15% by mass, air is used. There are cases where inconvenience arises because it becomes easy to take, and the appearance of the surface is impaired.

  In addition, natural polymers such as polyvinyl alcohol, polyethylene oxide, polyethylene glycol, polyacrylamide, and other natural polymers such as pectin, gelatin, casein, welan gum, gellan gum, locust bean gum, guar gum, etc., as long as the physical properties of the SL material are not adversely affected. It is possible to use a polymer derived from an object together.

  The amount of water is usually added in the range of 20 to 45% by mass of the entire system (the whole composition), preferably 24 to 40% by mass, more preferably 28 to 38% by mass. If the amount of water added is greater than 45% by mass, material separation may occur or curing may be significantly delayed. If the amount is less than 20% by mass, the necessary self-sufficiency may be achieved even if a water reducing agent is used. Leveling may not be obtained.

  The viscosity of the SL material of the present invention is 0.1 to 30 Pa · s, preferably 0.3 to 25 Pa · s, more preferably 0.5 to 20 Pa · s when measured at 10 rpm at 20 ± 3 ° C. is there. The method for measuring the viscosity of the SL material can be measured using, for example, a DPV-1 outer cylinder rotary viscometer manufactured by Kyowa Kagaku with a bob diameter of 30 mm. When the viscosity of the SL material is less than 0.1 Pa · s, material separation occurs, which may cause cracks and the like. On the other hand, if the viscosity is greater than 30 Pa · s, the viscosity is too high, and there may be a problem that sufficient self-leveling properties cannot be obtained.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.
<Materials used>
Cement: Ordinary Portland cement (manufactured by Taiheiyo Material)
Alumina cement: Alumina cement (La Fage)
Gypsum: Hemihydrate gypsum (made by Yoshino gypsum)
Sand: (1) Mineral sand (0.07-0.6mm)
(2) Mineral sand (0.05-0.1mm)
Talc: Talc (made by Nippon Talc)
Setting retarder: Sodium gluconate (reagent)
Setting accelerator: Calcium nitrite (reagent)
Polymer emulsion: RE530Z (Re-emulsification type: manufactured by Wacker)
Water reducing agent: Core Flow NF100 (manufactured by Taiheiyo Material)
Antifoaming agent: SN-14HP (San Nopco)
Water-soluble cellulose ether: shown in Table 1 below.
90SH-30000 (manufactured by Shin-Etsu Chemical Co., Ltd.)
SNB-30T (manufactured by Shin-Etsu Chemical Co., Ltd.)
SNB-15T (manufactured by Shin-Etsu Chemical Co., Ltd.)
MH-6000P6 (SE Tylose GmbH & Co
. Made)

ＨＰＭＣ：ヒドロキシプロピルメチルセルロース
ＨＥＭＣ：ヒドロキシエチルメチルセルロース

HPMC: Hydroxypropyl methylcellulose HEMC: Hydroxyethyl methylcellulose

<Combination>
Table 2 shows the formulation.

<Evaluation method>
A material other than water (powder) was previously blended, a predetermined amount of water was poured into a 5 liter mortar mixer, and the powder was added while stirring.
Kneading was performed for 3 minutes, and then the following measurements were performed.
<Measurement>
1. SL flow test (according to JASS 15M 103)
2. 2. SL material temperature SL material viscosity (Kyowa Kagaku DPV-1 viscometer, Bob diameter 30 mm, measured at 10 rpm)
4). Surface condition (SL material was poured into a plastic bat of 30 cm × 50 cm so as to have a thickness of 10 mm, and the number of pinholes on the surface after curing was confirmed and converted to the number per 10 cm square.)

<Result>
Table 3 shows the results.

As shown in Table 3, when the water-soluble cellulose ether of the present invention is used, the number of pinholes on the surface of the SL material after curing is 0.1 / 100 cm ² , which is a level that hardly generates pinholes. Excellent surface properties could be obtained. On the other hand, when the water-soluble cellulose ether of the comparative example is used, it is judged that the pinhole is generated so many that it does not lead to commercialization.

Claims (3)

Self that contains cement and / or gypsum, fine aggregate, inorganic filler, water reducing agent (fluidizer or dispersant), antifoaming agent, setting retarder, setting accelerator, water-soluble cellulose ether, and water as essential components It is a leveling composition, and the total amount of cement, gypsum, fine aggregate and inorganic filler is 100 parts by mass, and the amount of cement and / or gypsum used is 15 to 85 parts by mass, fine aggregate or fine aggregate The amount of inorganic filler used is 15 to 85 parts by weight, the amount of water-soluble cellulose ether used is 0.02 to 0.5% by weight, the amount of water reducing agent used is 0.01 to 5% by weight, and defoaming The amount of the agent used is 0.1 to 5% by mass, the amount of the setting retarder used is 0.001 to 5% by mass, the amount of the setting accelerator used is 0.005 to 3% by mass, and the amount of water added is a 20 to 45% by weight of the total composition, as the cellulose ethers, 14th revised Sieve remaining amount of the Japanese Pharmacopoeia B1061 sieve No. 100 according (eye open 150 [mu] m) is, self-leveling compositions, characterized in that using a surface-treated non water-soluble cellulose ether is not more than 5 wt%.   The self-leveling composition according to claim 1, which exhibits a viscosity of 0.1 to 30 Pa · s when measured at 20 rpm at 10 rpm.   The self-leveling composition according to claim 1 or 2, wherein the water-soluble cellulose ether is selected from methylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and hydroxyethylethylcellulose.