JPH05339041A - Aqueous composition for self-leveling type cement - Google Patents

Abstract

PURPOSE:To obtain the above compsn. having a long pot life and early solidification curing time by compounding a specific graft copolymer as a dispersant with a cement compd. CONSTITUTION:The aq. compsn. for self-leveling type cement is obtd. by compounding 1 to 20 pts.wt. (hereafter pts.), <=7 pts. water retaining agent, <=2 pts. defoaming agent, 30 to 300 pts. aggregate, 25 to 100 pts. water and 0.05 to 2.0 pts. dispersant with 100 pts. cement. The graft copolymer formed by copolymerizing the constituting units expressed by general formulas 1 to 4 (R<1> to R<4> denote H, methyl; R denotes 1 to 3C alkyl; M<1>, M<2> denote an alkali (alkaline earth) metal, org. amine; X denotes oxyethylene, oxyisopropylene, methylene; Y denotes a polymer block formed by radical polymn. of alpha,beta-unsatd. monomers having an amide group; m denotes 0 to 10; n denotes 0 to 30) at ratios of 40 to 80mol% formula I, 1 to 30mol% formula II, 1 to 20mol% formula III and 5 to 30mol% formula IV is used.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a self-leveling cement aqueous composition (hereinafter, simply referred to as SL material).
The SL material is widely used for the purpose of forming a smooth and horizontal floor surface by casting by utilizing the effect of gravity. The present invention relates to improvement of such SL material.

[0002]

2. Description of the Related Art Conventionally, SL materials have been supplied in powder form and used by mixing water immediately before pouring at a pouring site. However, the SL material becomes soft when the amount of kneading water is increased and the fluidity is increased, but on the other hand, the strength is deteriorated and the floating water amount is increased to impair the workability. In case of using, it is necessary to finely adjust the amount of water at the construction site, and it is really difficult to finely adjust the amount of water. Therefore, in recent years, a method has been adopted in which a plant dedicated to SL materials is installed, powder materials and water are consistently managed, SL materials in slurry form are manufactured in advance, and the SL materials are transported to the setting site and used as they are. Came to be. In this case, the SL material must have high fluidity until it is used from the SL material dedicated plant to the casting site, and it is necessary to secure a working time that can maintain stable fluidity for at least 5 to 6 hours. It is necessary, and it is desirable that light work can be performed on the floor the day after the SL material is placed in the working process. Therefore, the setting time is within 20 hours at the end of the setting time, and preferably within 15 hours. It is necessary.

As SL materials having high fluidity and ability to retain the fluidity, Japanese Patent Publication No. Sho 64-1425 and Japanese Examined Patent Publication No. 1-53.
There are proposals such as 226. However, the former conventional proposal has a drawback in that the fluidity and its retention ability are excellent, but the setting delay is large, and the latter conventional proposal has a small setting delay, but the fluidity and its It has the drawback of insufficient retention. In addition, these conventional proposals also have a drawback that many so-called initial cracks that cause cracks occur on the surface of the material during setting and hardening after the SL material is cast.

[0004]

The problem to be solved by the present invention is that, in the conventional SL material, both high fluidity and excellent retaining ability of the fluidity and small setting retardation property can be achieved. It is not possible and many initial cracks occur.

[0005]

However, the present inventors have
By solving the above problems, it has a high fluidity and its excellent holding ability, and therefore has a long pot life of about 5 to 6 hours in consideration of the actual situation, and at the same time has a small setting delay property. Therefore, in consideration of the actual situation, as a result of earnest research to obtain an SL material having a fast setting hardening time of about 10 to 15 hours and having very few initial cracks,
As a cement dispersant, α having an amide group in the molecule,
Using a specific graft copolymer obtained by grafting a polymer block obtained by radically polymerizing a β-unsaturated monomer, and using this in combination with other materials in an appropriate ratio is correct and suitable. I found it.

That is, the present invention is based on 100 parts by weight of cement, 1 to 20 parts by weight of a swelling agent, 7 parts by weight or less of a water retention agent, 2 parts by weight or less of a defoaming agent, and 30 to 300 parts by weight of an aggregate. Water is 25-100 parts by weight and dispersant is 0.05-
An SL material compounded at a ratio of 2.0 parts by weight, in which the dispersant is a structural unit represented by the following formula 1, a structural unit represented by the following formula 2, and a structural unit represented by the following formula 3. And a SL material which is a graft copolymer composed of structural units represented by the following formula 4.

[0007]

[Formula 1]

[0008]

[Formula 2]

[0009]

[Formula 3]

[0010]

[Formula 4]

[In the formulas 1 to 4, R ^{1 to} R ^{4 are the} same or different at the same time, H or CH ₃ R ^{5 is} an alkyl group having 1 to ⁵ carbon atoms, M ¹ and M ² are alkali metals and alkaline earth metals. Or organic amine X: CH ₂ CH ₂ O, CH ₂ CH (CH ₃ ) O or CH ₂ Y: a polymer block obtained by radically polymerizing an α, β-unsaturated monomer having an amide group in the molecule m: integer of 0 to 10 n: integer of 0 to 30]

Each constituent unit of the graft copolymer used for the SL material of the present invention represents a unit of a monomer which forms each of them. Examples of the monomer that forms the structural unit represented by Formula 1 (hereinafter referred to as structural unit A) are 1) alkali metal salts such as lithium salt, sodium salt, and potassium salt of (meth) acrylic acid, 2) ( Examples thereof include alkaline earth metal salts such as calcium salts and magnesium salts of (meth) acrylic acid, and 3) organic amine salts such as diethanolamine salts and triethanolamine salts of (meth) acrylic acid.

Monomers that form the structural unit represented by Formula 2 (hereinafter referred to as structural unit B) include alkanediol mono (meth) acrylate and polyalkylene glycol mono (meth), each having a polymer block Y. ) Acrylate is included. Examples of the alkanediol mono (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 1,4-butanediol mono (meth) acrylate, and 1,6-hexanediol mono (meth) acrylate. ) Acrylate and the like, and as the polyalkylene glycol mono (meth) acrylate,
Examples thereof include polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, and poly (ethylene / propylene) glycol mono (meth) acrylate. Among them, 2-hydroxyethyl methacrylate, polyethylene glycol (ethylene oxide addition moles). Number n = 2 to 10) Monomethacrylate is preferred.

The α, β-unsaturated monomer having an amide group in the molecule necessary for forming the polymer block Y of the structural unit B is 1) (meth) acrylamide, 2) N.
-N-alkyl-substituted (meth) acrylamides such as -methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, Nt-butyl (meth) acrylamide, 3) N-methoxymethyl (meth) acrylamide,
N-ethoxyethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N-methylol (meth)
N-substituted (meth) acrylamides such as acrylamide,
4) (meth) acrylamide sulfonate such as (meth) acrylamide methanesulfonic acid or a salt thereof, (meth) acrylamideethanesulfonic acid or a salt thereof, 2- (meth) acrylamide-2-methylpropanesulfonic acid or a salt thereof, 5) N-vinylformamide, N-methyl,
N-vinylformamide, N-vinylacetamide, N
N-vinyl amides such as -methyl, N-vinyl acetamide, 6) N-vinyl-2-pyrrolidone, N-vinyl-5
-Methylpyrrolidone, N-vinyl-5-butylpyrrolidone, N-ethyl-3-vinylpyrrolidone, N-ethyl-
Examples thereof include vinyl-substituted lactams such as 5-vinylpyrrolidone. Among them, (meth) acrylamide, 2-
(Meth) acrylamido-2-methylpropanesulfonic acid or a salt thereof is preferable.

The monomer that forms the constitutional unit represented by the formula 3 (hereinafter referred to as constitutional unit C) is
1) Alkali metal salts such as lithium salt, sodium salt and potassium salt of methallyl sulfonic acid, 2) Alkaline earth metal salts such as calcium salt and magnesium salt of methallyl sulfonic acid, 3) Diethanolamine salt of methallyl sulfonic acid And organic amine salts such as triethanolamine salt.

The monomer that will form the structural unit represented by Formula 4 (hereinafter referred to as structural unit D) includes an alkoxypolyethylene glycol (meth) acrylate having an alkoxy group having 1 to 5 carbon atoms and 1 to 1 carbon atom. Alkyl (meth) acrylates having 5 alkyl groups are included. Examples of such alkoxy polyethylene glycol (meth) acrylate include esters of alkoxy polyethylene glycol such as methoxy polyethylene glycol, ethoxy polyethylene glycol, (iso) propoxy polyethylene glycol, butoxy polyethylene glycol and (meth) acrylic acid, and alkyl ( Examples of the (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, (iso) propyl (meth) acrylate, and butyl (meth) acrylate. Among them, methoxypolyethylene glycol methacrylate and methyl acrylate are preferable. preferable.

The graft copolymer in the present invention is composed of the structural units A to D as described above, and the respective proportions of the structural units A to D in the graft copolymer are the structural units A to D. / Structural unit B / Structural unit C / Structural unit D = 40 to 80/1 to 30/1 to 20/5 to 30 (mol%), and preferably 50 to 75/3 to
It is more preferable to set it to 25/3 to 20/5 to 30 (mol%). Among the structural units A to D, the structural unit B is particularly important. This is because by introducing the structural unit B having the polymer block Y into the graft copolymer, the desired effect of the present invention is exhibited, and in view of the effect, the polymer block Y / graft polymerization is performed. It is preferable that the former copolymer = 1/100 to 100/100 (weight ratio).

Next, the method for producing the graft copolymer in the present invention will be described. The graft copolymer can be obtained by a known copolymerization reaction using the above-mentioned monomers that will form the structural units A to D, and the method is not particularly limited, but the polymer is previously described. Block Y
To obtain a copolymer, and then add an α, β-unsaturated monomer having an amide group in the molecule to form the polymer block Y to the copolymer. The method obtained by the graft polymerization reaction of is preferable. The polymerization method is preferably aqueous solution polymerization using water or a mixed solvent of water and a water-soluble organic solvent.

As the radical initiator used in the copolymerization reaction and the graft polymerization reaction to the copolymer, the type of radical initiator is limited as long as it decomposes at the temperature of the copolymerization reaction and the graft polymerization reaction to generate a radical. Although it is not a thing, it is preferable to use a water-soluble radical initiator. Examples of such water-soluble radical initiators include persulfates such as potassium persulfate and ammonium persulfate, hydrogen peroxide, and 2,2-azobis (2-amidinopropane) dihydrochloride. These can also be used as a redox initiator in combination with a reducing substance such as sulfite or L-ascorbic acid, as well as an amine. In addition, a ceric ammonium salt such as ceric ammonium nitrate or ceric ammonium sulfate can be used as a strong oxidant, but particularly in a graft polymerization reaction in which the polymer block Y is bonded to the copolymer, It is advantageous to use a ceric salt catalyst as the oxidizing agent in order to obtain a high yield of the graft polymerization reaction.

An example of a specific method for producing the graft copolymer in the present invention is shown below. First, each monomer except the polymer block Y is dissolved in water to prepare an aqueous solution containing the monomer in a total amount of 10 to 45% by weight. Add a radical initiator to this and add 50 to 70 in a nitrogen gas atmosphere.
Copolymerization reaction is performed at 4 ° C. for 4 to 6 hours to obtain a copolymer. Next, an aqueous solution prepared by dissolving the obtained copolymer and an α, β-unsaturated monomer having an amide group in the molecule in water is prepared,
After replacing the reaction solution with nitrogen, add a radical initiator to
The graft copolymerization reaction is carried out at ˜70 ° C. for 3 to 6 hours to obtain a graft copolymer. The number average molecular weight of the copolymer, excluding the polymer block Y, corresponding to the precursor of the graft copolymer is preferably in the range of 2000 to 20000 (GPC method, pullulan conversion). Further, the graft copolymer in which the polymer block Y is bound by the graft polymerization reaction has a reduced viscosity (20 ° C.) at a concentration of 1% using 1N saline as a solvent and is within a range of 0.05 to 1.0. Those having a range of 0.10 to 0.8 are more preferable.

The dispersant composed of the above-mentioned graft copolymer used in the SL material of the present invention is blended at a ratio of 0.05 to 2.0 parts by weight to 100 parts by weight of cement, preferably 0. It is compounded in a ratio of 2 to 1.5 parts by weight. If the blending ratio is less than the above, the fluidity and its retaining ability will be reduced, and the effect of reducing initial cracking will also be reduced. On the other hand, if the blending ratio is higher than the above range, the retardation of setting becomes large, causing curing failure, and material separation, which makes it difficult to obtain a homogeneous cured product.

The effect of reducing initial cracks can be obtained more efficiently by using a polyorganosiloxane together with a dispersant composed of the above graft copolymer. Examples of such polyorganosiloxane include polydimethylsiloxane having a molecular weight of 1,000 to 10,000, and among them, an aqueous dispersion emulsion of the polydimethylsiloxane can be advantageously used. Polydimethylsiloxane is added in an amount of 1 part by weight or less based on 100 parts by weight of cement.

As the cement used in the SL material of the present invention, as Portland cement, ordinary cement, early-strength cement, ultra-early-strength cement, moderate heat cement, sulfate resistant cement, etc., and mixed cement with blast furnace cement, fly ash cement, Silica cement or the like can be used.

The expansive material used for the SL material of the present invention is to prevent cracking due to shrinkage that occurs during hardening and drying of the cement after setting and hardening. Examples of the expansive material include one containing lime as a main component and one containing calcium sulfoaluminate as a main component. Specific commercially available expansive materials include Onoda Expan (made by Onoda Cement Co., Ltd.) containing lime as a main component, and Denka CS containing calcium sulfoaluminate as a main component.
A (manufactured by Denki Kagaku Kogyo Co., Ltd.) and the like. The expansive material is blended at a ratio of 1 to 20 parts by weight with respect to 100 parts by weight of cement,
It is preferably blended in a proportion of 4 to 12 parts by weight. If the blending ratio is less than the above, cracking occurs on the surface of the flooring material due to drying shrinkage. On the contrary, if the blending ratio is more than the above, the floor surface swells or breaks due to expansion.

The water retention agent used in the SL material of the present invention is for preventing the phenomenon that the floor surface becomes fragile due to drying especially under high temperature and drying conditions. As such a water retention agent, a generally known water retention agent can be used, and examples thereof include water-soluble polymers such as cellulose ether, polyvinyl alcohol, and polyether, and latex rubber, but among them, methyl cellulose, hydroxyethyl cellulose, and hydroxy. Cellulose ethers such as propylmethyl cellulose can be used advantageously. The water retention agent is mixed in a ratio of 7 parts by weight or less, preferably 0.06 to 3 parts by weight, relative to 100 parts by weight of cement. If the blending ratio is higher than the above, the amount of water required to obtain fluidity increases remarkably, resulting in a problem such as a decrease in strength.

The antifoaming agent used in the SL material of the present invention is for preventing the floor surface from swelling and denting due to air bubbles. As such an antifoaming agent, a generally used antifoaming agent such as a silicone-based or nonionic surfactant can be used. The defoaming agent is blended in a ratio of 2 parts by weight or less, preferably 0.1 to 0.5 parts by weight, based on 100 parts by weight of cement. The defoaming effect does not change even if the blending ratio is higher than the above.

As the aggregate used for the SL material of the present invention, river sand, sea sand, land sand, crushed sand, silica sand and the like can be used. Dry sand is preferable as these sands, but wet sand does not cause any problem. For the purpose of reducing the weight, perlite, fly ash and the like may be used alone or in combination with the above sand and the like. The aggregate is mixed in an amount of 30 to 300 parts by weight, preferably 60 to 150 parts by weight, based on 100 parts by weight of cement. When the blending ratio is less than the above, the fluidity is not maintained for a long time, and when it is more than the above, the strength is low and the fluidity is poor.

As the water used for the SL material of the present invention, tap water, industrial water, etc. can be used. Water is mixed in a ratio of 25 to 100 parts by weight with respect to 100 parts by weight of cement. If the blending ratio is less than the above, high fluidity cannot be obtained,
On the other hand, when the amount is larger than the above, white sinter and breathing water are liable to be generated, and the strength is lowered.

For the SL material of the present invention, calcium carbonate, gypsum, siliceous fine powder, fly ash and the like can be used as an extender, for example, as long as they do not adversely affect the desired physical properties. Examples are given below in order to make the constitution and effects of the present invention more specific, but the present invention is not limited to these examples.

[0030]

【Example】

Test Category 1 (Production of Graft Copolymer) Graft copolymers (G-1 to G-7) were produced as follows. The contents are summarized in Tables 1 and 2. -Production of graft copolymer (G-1) 66 parts of methacrylic acid (parts by weight, the same applies hereinafter), 28.5 parts of 2-hydroxyethyl methacrylate, 31 parts of sodium methallyl sulfonate, methoxy polyethylene glycol (moles of ethylene oxide added) (N = 23) 273 parts of monomethacrylate and 500 parts of water are charged into a reaction vessel, and 64 parts of a 48% (wt%, hereinafter the same) aqueous solution of sodium hydroxide is added to neutralize and uniformly dissolve, and then the atmosphere Was replaced with nitrogen. The temperature of the reaction system was kept at 60 ° C. in a warm water bath, and 75 parts of a 15% aqueous solution of ammonium persulfate was added to initiate polymerization, and the polymerization reaction was continued for 5 hours to give a copolymer (number average molecular weight of 5000, GPC method, pullulan conversion, the same hereinafter) was obtained.

370 parts of the copolymer obtained above, 260 water
Part, acrylamide 24 parts and 2-acrylamide-2
12 parts of sodium methyl propane sulfonate was charged into another reaction vessel and dissolved uniformly, and then the atmosphere was replaced with nitrogen. The temperature of the reaction system was maintained at 55 ° C. in a warm water bath, and 12 parts of a ceric ammonium nitrate solution (1/10 mol of cerium ion in 1N nitric acid) was added to carry out a graft polymerization reaction. The product was concentrated with an evaporator, precipitated and purified in a mixed solvent of acetone / ethyl acetate, and dried to obtain a graft copolymer (G-1).

Analysis of the graft copolymer (G-1) revealed that the carboxyl value was 85, the nitrogen content was 2.9%, the sulfur content was 1.7%, and the reduced viscosity (1% concentration, 20 ° C., 1N).
(In NaCl aqueous solution) was 0.27, and the graft copolymer (G-1) was found to be sodium methacrylate / 2-hydroxyethyl methacrylate / sodium methallyl sulfonate according to the measurement results of pyrolysis gas chromatography and NMR. / Methoxy polyethylene glycol (n = 2
3) Methacrylate = 53/15/14/18 (molar ratio) Before the graft polymerization, the copolymer was used as a polymer block, and polyacrylamide / 2-acrylamido-2-methylpropanesulfonic acid sodium salt = 92
The copolymer composed of / 8 (molar ratio) was graft-polymerized, and had a ratio of graft polymer block / copolymer before graft = 21/100 (weight ratio). .. Similarly, the graft copolymer (G
-2-G-7) were obtained.

[0033]

[Table 1]

[0034]

[Table 2]

In Tables 1 and 2, equivalent to constitutional unit B: equivalent to the case where Y is hydrogen in the above-mentioned formula 2 Ratio: graft polymer block Y / copolymer before graft polymerization (weight ratio) * 1 Reduced viscosity (20 ° C.) of a graft copolymer at a concentration of 1% using 1N saline as a solvent a: sodium methacrylate b: sodium acrylate c: 2-hydroxyethyl methacrylate d: polyethylene glycol (n = 9) Monomethacrylate e: sodium methallyl sulfonate f: methoxypolyethylene glycol (n = 23) methacrylate g: methoxypolyethylene glycol (n = 9) methacrylate h: methyl acrylate p: acrylamide q: methacrylamide r: 2-acrylamide-2 -Sodium methyl propane sulfonate

Test Category 2 (Production of SL Material and Comparison of Physical Properties of SL Material) SL materials were prepared at the compounding ratios shown in Tables 3 and 4. In each of the examples, the dispersant was blended at a ratio of 1.0% or less in terms of solid content with respect to the cement so that the target flow value when kneading was in the range of 220 to 230 mm. Then, for each SL material prepared, a flow value by the following measurement method,
The J funnel value, setting time, compressive strength, surface strength, and rate of change in length were measured. The results are summarized in Tables 5 and 6.

-Measurement method All materials were kneaded in a mixing ratio shown in Tables 3 and 4 using a Hobart mixer for 2 minutes to prepare a SL material in a uniform state. Then, the SL material was subjected to each measurement.

.. Flow value The SL material is packed in a flow cone having an inner diameter of 51 mm and a height of 50 mm, the cone is pulled up, and the diameter of the spread width when the spread of the SL material is at rest is measured in two directions at right angles. The average value was calculated.

..Change in flow value with time Hold the prepared SL material in a stationary state, and after 3 hours and 6
After the lapse of time, after kneading with a kneading spoon for about 1 minute, an average value was obtained according to the above measurement of the flow value.

.. J-Rot value The J-Rot value was measured in accordance with the "Construction Material Standard Handbook (edited by the Japan Society for Materials)" consistency test method (draft) 17. J
The funnel used had an inner diameter of the outlet of 10 mm.

.. Change in J funnel value with time Hold the prepared SL material in a stationary state, and after 3 hours and 6
After the time, knead with a kneading spoon for about 1 minute, and then mix with the above J
It was measured according to the measurement of the funnel value.

.. All of the setting time, compressive strength and length change rate were measured according to JIS-R-5201.

..A steel flat plate having a surface strength of 40 mm × 40 mm is attached to the surface of the cured SL material on the 28th day with an epoxy adhesive and pulled by a hydraulic jack until the flat plate is peeled off, and the maximum pulling force at that time Was measured.

[0044]

[Table 3]

In Table 3, * 1: The types and blending amounts of the dispersants are summarized in Table 4. * 2: Polydimethylsiloxane (number average molecular weight 200
Aqueous dispersion of 0) Cement: Ordinary Portland cement manufactured by Onoda Cement Co., Ltd. Aggregate: Yamagata silica sand, F.I. M = 2.3 Expansion material: Onoda Expan made by Onoda Cement Co., Ltd. Water retention agent: Metroses made by Shin-Etsu Chemical Co., Ltd., molecular weight 8000 Defoaming agent: SN-deformer made by San Nopco Water: Gamagori-shi water

[0046]

[Table 4]

In Table 4, M-1 to M-4: Compounding conditions described in Table 3 G-1 to G-7: Graft copolymer produced in Test Category 1 R-1: Sodium methacrylate / 2- Copolymer (number average molecular weight 5000) composed of hydroxyethyl methacrylate / sodium methallyl sulfonate / methoxy polyethylene glycol (n = 23) methacrylate = 53/15/14/18 (molar ratio) R-2: methacrylic acid Sodium / polyethylene glycol (n = 9) monomethacrylate / sodium methallyl sulfonate / methoxy polyethylene glycol (n =
9) Methacrylate = 60/5/10/25 (molar ratio)
(Number average molecular weight 8500) R-3: sodium methacrylate / methoxy polyethylene glycol (n = 10) methacrylate = 64/36
Copolymer composed of (molar ratio) (Japanese Patent Publication No. 64-142)
No. 5) R-4: sodium salt of formalin condensate of naphthalene sulfonic acid R-5: sodium salt of formalin condensate of melamine sulfonic acid Dispersant content: 100 parts by weight of cement

[0048]

[Table 5]

[0049]

[Table 6]

Test Category 3 (Production of SL Material and Physical Properties of SL Material) Example 12 Each material was weighed in a blending amount shown in Table 7 in a mortar mixer having a volume of 1 m ³ and rotating at 300 rpm for 10 minutes. Kneading was performed to produce about 0.5 m ³ of SL material. The flow value at the time of kneading was 230 mm, and the J funnel value was 32 seconds. The obtained SL material was put into an agitator car having a drum rotation speed of 0.7 rpm, and after about 5.5 hours from the end of kneading, an acrylic primer was sufficiently applied to prepare a mortar structure. Was placed on the floor. The flow rate of the SL material at the time of casting was 226 mm and the J funnel value was 35 seconds, and the decrease in fluidity due to the elapsed time was extremely small.
The setting was completed within about 15 hours after kneading. The surface condition until hardening was observed, but initial cracking due to cracking did not occur. Further, even after curing, a smooth and horizontal floor surface could be formed without cracking due to shrinkage. In addition, when the slurry just after kneading was sampled and the physical properties were measured, the compressive strength was 28
350Kgf / cm ² per day, surface strength is 13.8K after 14 days
It was gf / cm ² , and good strength was obtained.

[0051]

[Table 7]

In Table 7, * 3: Blast furnace cement * 4: Graft copolymer G-1 produced in test category 1 * 5: Material used in test category 2

[0053]

As is apparent from the above, the present invention described above has a high fluidity and an excellent holding ability, and therefore has a long pot life in accordance with the actual situation, and at the same time has a small setting. There is an effect that it is possible to obtain a high-quality cured product which has a delay property and therefore has a fast setting and hardening time in accordance with the actual situation, and has very few initial cracks.

Continuation of the front page (72) Inventor Atsue Kameoka 2-13-14 Minamikasai, Edogawa-ku, Tokyo Onoda Cement Kasai Dormitory (72) Inventor Mitsuo Kinoshita 308 Shiiki, Tomegawa-cho, Toyokawa-shi, Aichi (72) Inventor Miura Yoshimasa 55, Nakayashiki, Ugaike-cho, Nishio-shi, Aichi (72) Inventor Tsuneo Yamamoto 76, 1-cho, Machibata, Toyohashi-shi, Aichi

Claims (4)

[Claims] 1. A swelling agent is 1 to 20 parts by weight, a water retention agent is 7 parts by weight or less, an antifoaming agent is 2 parts by weight or less, an aggregate is 30 to 300 parts by weight, and water is 25 parts by weight with respect to 100 parts by weight of cement. -10
A self-leveling cement aqueous composition in which 0 part by weight and a dispersant are blended in a ratio of 0.05 to 2.0 parts by weight, wherein the dispersant is a constitutional unit represented by the following formula 1 and the following formula: A self-leveling cement aqueous composition, which is a graft copolymer composed of a constitutional unit represented by 2 and a constitutional unit represented by the following formula 3 and a constitutional unit represented by the following formula 4. [Formula 1] [Formula 2] [Formula 3] [Formula 4] [In Formulas 1 to 4, R ^{1 to} R ^{4 are the} same or different at the same time, H or CH ₃ R ^{5 is} an alkyl group having 1 to ⁵ carbon atoms M ¹ and M ² : alkali metal, alkaline earth metal or organic amine X: CH ₂ CH ₂ O, CH ₂ CH (CH ₃ ) O or CH ₂ Y: a polymer block obtained by radical polymerization of an α, β-unsaturated monomer having an amide group in the molecule m: 0 10 to integer n: 0 to 30 integer] 2. Y in formula 2 is (meth) acrylamide, 2
A polymer block obtained by radical polymerization of one or more selected from-(meth) acrylamido-2-methylpropanesulfonic acid and salts thereof.
The self-leveling cement aqueous composition described. 3. The graft copolymer has a structural unit represented by formula 1 of 40 to 80 mol%, a structural unit of formula 2 is 1 to 30 mol%, and a structural unit of formula 3 is 1 to 20. The self-leveling cement aqueous composition according to claim 1 or 2, wherein the constitutional units represented by mol% and the formula 4 are constituted in a proportion of 5 to 30 mol%. 4. The self-leveling cement aqueous composition according to claim 1, wherein the polyorganosiloxane is further mixed in a ratio of 1 part by weight or less with respect to 100 parts by weight of the cement.