JPH04209737A - Self-leveling cement water base composition - Google Patents

Abstract

PURPOSE:To provide the title composition capable of retaining high fluidity for a long time, also short in setting time, containing, as dispersant, a specific water-soluble vinyl copolymer having sulfonic acid group at the terminal of the main chain. CONSTITUTION:First, a dispersant consisting of a water-soluble vinyl copolymer having sulfonic acid group at the terminal of the main chain is prepared by the following process: a copolymerization is made in the presence of a radical initiator between (l) a vinyl monomer of formula I and (2) a second vinyl monomer of formula II at the molar ratio I/II=(50:50) to (95:5); a radical initiator is then added to the resulting two-component copolymer to effect radical activation followed by radical addition of a third vinyl monomer of formula (in the formulas I-III, R<1>-R<5> and R<7> are each H or CH3; R<6> is 1-3C alkyl; X and Y are each alkali metal, ammonium or organic amine; (n) is 5-25). Then, (A) 100 pts.wt. of cement is incorporated with (B) 0.05-2 pts.wt. of the above dispersant, (C) 1-20 pts.wt. of an expanding material, (D) 0.01-7 pts.wt. of a water-holding agent, (E) 0.01-2 pts.wt. of a defoaming agent, (F) 30-300 pts.wt. of aggregates, and (G) 25-100 pts.wt. of water, thus obtaining the objective composition.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a self-leveling cement aqueous composition (hereinafter referred to as SL material), and more particularly to a cement-based self-leveling flooring material.

<Prior art and its problems> The use of SL material has already been widely practiced in order to form a flat floor surface.

Previously, self-leveling materials were supplied in powder form and mixed with water at the pouring site. However, it is difficult to adjust the amount of water required to obtain uniform fluidity, and a higher quality slurry is desired.In order to supply SL material with a higher quality slurry,
Powder materials and water must be managed appropriately. 1. Therefore, we have set up a manufacturing facility exclusively for SL materials, and are able to produce powder materials and wood in a consistent manner. management is required.

If manufacturing equipment is set up specifically for SL materials and slurry is manufactured, it must maintain high fluidity from the time it is manufactured until it is used on site, and the fluidity must remain stable for at least 5 to 6 hours. is desired.

In addition, due to the work process, it is desirable to be able to perform light work on the floor the day after pouring the SL material, so the setting time for the SL material should be within 20 hours, preferably within 15 hours. This is required.

Generally, various types of cement dispersants are commercially available, but the dispersants used for SL#Ii preparation are carboxylate-based ones and sulfonate-based ones such as lignin-based and naphthalene-based ones. It is broadly divided into.

Examples of carboxylic acid salts include, for example, Japanese Patent Publication No. 64-1
425, which has the advantage of being able to maintain high fluidity for a long time, but has the disadvantage of delaying setting, and when used in SL agents, setting time is 20
Transcend time.

Normally, setting time can be shortened by limiting the use of water and water retention agents, but when using carvone salt-resistant dispersants, the setting delay effect of the dispersant itself is large, so water, The use of water retention agents is kept to the minimum necessary.

Furthermore, if the setting time is adjusted to be short by limiting the use of water and water retention agents, a phenomenon occurs in which the floor surface becomes crumbly due to drying under high temperature or dry conditions.

On the other hand, as sulfonate-based compounds, for example, Japanese Patent Publication No. 1
-53226, and when only the dispersant itself is used, it is not possible to maintain high fluidity for a long time, so a setting retarder is usually used in combination. However, although it is possible to maintain high fluidity for a long time by using a setting retarder in combination, the setting time is much slower than that of carboxylic acid salts. Here, it is possible to promote coagulation by using an alkali metal #1 (for example, alkali carbonate, alkali bicarbonate, etc.) as a curing accelerator, but it becomes difficult to control the time to maintain high fluidity. In addition, S with a high fluidity time of about 6 hours
When making L material, it is not economical because a large amount of retardant is used.Also, when using a curing accelerator such as alkali carbonate, the strength of the cured product as a member decreases as the amount used increases. There are other problems.

Thus, an SL material that can simultaneously satisfy the two requirements of a long pot life of 5 to 6 hours and a relatively quick setting and hardening of 12 to 15 hours has not yet been developed.

<Problems to be Solved by the Invention and Means for Solving the Problems> The present invention provides an SL material that solves the conventional problems as described above and satisfies two demands at the same time.

However, as a result of intensive research to develop an SL material with a pot life of 5 to 6 hours and a setting time of 12 to 15 hours, the present inventors found that it has a sulfonic acid group at the end of the main chain as a cement dispersant. By using a water-soluble vinyl copolymer with a controlled structure and using this in combination with other materials in appropriate proportions, we have created an SL that maintains high fluidity for a long time and has a short setting time.
The present invention was completed based on the discovery that a material can be obtained.

That is, in the present invention, 1 to 20 parts by weight of an expanding agent is added to 100 parts by weight of cement,
0.01 to 7 parts by weight of water retention agent, 0.01 to 2 parts by weight of antifoaming agent, 30 to 300 parts by weight of aggregate, 25 to 20 parts by weight of water,
and dispersant 0.05-2! SL containing i part of
The dispersant comprises a vinyl monomer represented by the following formula (1) and a vinyl monomer represented by the following formula (2). After copolymerizing the vinyl monomer represented by (2) in the presence of a radical initiator at a ratio of 50,150 to 9,515 (mole ratio), radical termination is performed to obtain a binary copolymer, and then the binary After adding a radical initiator to the original copolymer to form a radically activated binary copolymer, a vinyl monomer represented by the following formula (3) is added to the radically activated binary copolymer. A water-soluble vinyl copolymer having a sulfonic acid group at the end of the main chain produced by radical addition of one or more of
Concerning L material.

Formula (1): Formula (2) Near CH2C-CH2SO3Y [In Formulas (1) to (3), R1, -R5, 1177 are simultaneously the same or different, H
Or CH3@R6 is an alkyl group having 1 to 3 carbon atoms.

X, Y are alkali metals, alkaline earth metals, ammonium, or organic amines n is an integer of 5 to 25. ] The dispersant is used to obtain high fluidity of the SL material slurry, and the dispersant used in the present invention is expressed by formula (1)
A regulated structure having a sulfonic acid group as a polar group at the end of the main chain of a vinyl copolymer obtained by copolymerizing the vinyl monomer represented by and the vinyl monomer represented by formula (2). It is made of water-soluble vinyl copolymer. The water-soluble vinyl copolymer can be produced by a specific method as described below. This production method is roughly divided into the N41 step, the second step, and the third step.

The first step is to radically copolymerize the vinyl monomer represented by the formula (1) and the vinyl monomer represented by the formula (2) at a predetermined ratio, and then radically terminate the vinyl monomer represented by the formula (2). (1)
This is a step of obtaining a binary copolymer consisting of a vinyl monomer represented by the formula (2) and a vinyl monomer represented by the formula (2).

Examples of the vinyl monomer represented by formula (1) include alkali metal salts, alkaline earth metal salts, and alkanolamine salts of acrylic acid, methacrylic acid, and crotonic acid. In addition, examples of the vinyl monomer represented by formula (2) include methoxypolyethylene glycol, ethoxypolyethylene glycol, propoxypolyethylene glycol 5, impropoxypolyethylene glycol, methoxypolyethylenepolypropylene glycol, or ethoxypolyethylenepolypropylene glycol with one terminal end-blocked with an alkyl group. There is an esterified product of polyalkylene glycol and acrylic acid, methacrylic acid, or crotonic acid, in which the number of added moles of polyalkylene glycol is 5 to 25.

In the first step of the sea bream production method, vinyl monomer represented by formula (1)/vinyl monomer represented by formula (2) = 50150
~9515 (molar ratio), preferably 55/45 ~ 85/
Both are copolymerized at a ratio of 15 (molar ratio).

The copolymerization reaction between the vinyl monomer represented by formula (1) and the vinyl monomer represented by formula (2) is as follows.

As the radical initiator used in the copolymerization reaction, which is preferably carried out by aqueous solution polymerization using water or a mixed solvent of water and a water-soluble organic solvent, it is advantageous to use a water-soluble radical initiator.

In the first step of the production method, in the radical copolymerization of the two types of vinyl monomers described above, the reaction system is radically terminated in a timely manner to obtain a binary copolymer. There are roughly two types of methods. The first method is to continue the reaction until the radicals completely disappear from the reaction system and the radical copolymerization reaction substantially stops. The second method is to add to the reaction system a radical terminator that forcibly decomposes and eliminates radicals.

Conventionally known compounds can be used as such radical terminators. Radical terminators that can be used advantageously include 3-mercapto-1,2-propanediol, dithioerythritol, 2-mercaptoethanol, 1.
There are compounds such as 2-ethanedithiol that have at least 2 (1) active hydrogen groups such as hydroxyl groups or thiol groups in the molecule. Other radical terminators that can be advantageously used include thiol groups and α, β -, β-hydrocarbon groups.More specifically, such compounds include α,β-unsaturated monocarboxylic acid solcapto, such as mercaptoethyl (meth)acrylate, mercaptoethyl crotonic acid ester, etc. Alkyl ester.

The second step of the production method is a step of adding a radical initiator to the binary copolymer obtained in the first step to obtain a binary copolymer in which the terminal of the main chain is radically activated.

The radical initiator used in the second step may be the same as the radical initiator used in the first step.

For the binary copolymer obtained by radical termination without using a radical terminator in the first step, the radical of the vinyl monomer represented by the formula (3) used in the next third step In order to add efficiently and selectively,
It is preferable to add an azobis-based compound having a hydroxyl group in the molecule as a radical initiator. Examples of azobis-based compounds having hydroxyl groups in nine molecules, which do not limit the application thereof, include 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2° -azobis[2-methyl-N-(
1,1-bis(hydroxymethyl)ethylnoprobionamidoco, 2,2'-azobis[2-methyl-N-(1
.

l-bis(hydroxymethyl)-2-hydroxyethyl)propionamide] and the like.

In the third step of the production method, a vinyl monomer represented by formula (3) is radically added to the binary copolymer obtained in the second step, in which the end of the main chain is radically activated. This is a process for obtaining a water-soluble vinyl copolymer having a sulfonic acid group at the end.

Examples of the vinyl monomer represented by formula (3) include alkali metal salts, alkaline earth metal salts, and alkanolamine salts of allylsulfonic acid and methallylsulfonic acid.

The reaction ratio between the binary copolymer whose main chain end is radically activated obtained in the second step and the vinyl monomer represented by formula (3) is usually The amount is 1 to 10 mol, preferably 1.5 to 5 mol, per 1 mol of the combined compound. The radical addition reaction itself between the binary copolymer whose main chain end is radically activated obtained in the second step and the vinyl monomer represented by formula (3) is carried out in accordance with the known radical solution polymerization method. It can be done.

According to the production method described above, in the radical addition reaction between the binary copolymer whose main chain terminal is radically activated and the vinyl monomer represented by formula (3), the terminal of the main chain is radically activated. 1 per terminal radical active site of binary copolymer
A (meth)allylsulfonate addition of the molecule is obtained. When radically adding one molecule of sulfonic acid vinyl monomer per terminal radical active site, the formula (3
) has extremely high reaction selectivity compared to other sulfonic acid-based vinyl monomers; A vinyl copolymer is obtained.

The water-soluble vinyl copolymer having a sulfonic acid group at the end of the main chain thus obtained has a number average molecular weight of 20 in terms of polyethylene glycol measured by GPC method.
00 to 15,000 is preferable, and 3,000 to 1oo
oo is more preferable.

The amount of the dispersant made of the water-soluble vinyl copolymer used is 0.05 to 2.0 parts by weight, preferably 0.2 parts by weight in terms of solid content.
~1.0 parts by weight (all parts by weight relative to 100 parts by weight of cement, the same applies hereinafter). If the amount used is less than the above, high fluidity cannot be obtained, and even if it is used in a larger amount than the above, the effect will not change.

Cement includes ordinary cement, early-strength cement, ultra-early-strength cement, medium-heat cement, sulfate-resistant cement, etc. as Portland cement, and blast furnace cement as mixed cement.
Ply ash cement, silica cement, etc. can be used.

The expansion material is used to prevent cracks caused by shrinkage that occurs when cement hardens and dries. Examples of the No. 11 tension material include those containing lime as a main component and those containing calcium sulfoaluminate as a main component, and any of these materials can be used. Examples of commercially available expanding materials include Onoda Expan (manufactured by Onoda Cement Co., Ltd.) for lime-based materials, and Denka C5A (manufactured by Denki Kagaku Kogyo Co., Ltd.) for calcium sulfoaluminate-based materials.

The amount of expansion material used is 1 to 20 parts by weight, preferably 4 to 12 parts by weight.
Parts by weight. If the amount used is less than the above, cracks will occur on the surface of the flooring material due to drying shrinkage, and if it exceeds the above amount, the floor surface will bulge or break due to expansion.

Water retention agents are used to prevent the floor surface from becoming crumbly due to drying, especially under high temperature and dry conditions.In the present invention, commonly used water retention agents, thickeners, Viscosity modifiers and the like can be used. Commercially available water retention agents include cellulose-based ones, acrylic acid-based ones, polyvinyl alcohol, polyethylene oxide, vinyl-based ones, rubber, latex-based ones, etc. In the present invention, cellulose-based ones are particularly used. The amount of water retention agent used is preferably 0.01 to 7 parts by weight, preferably 0.06 to 3 parts by weight. If the amount used is less than the above, phenomena such as dry out and the floor surface becoming crumbly will become noticeable, and if it exceeds the above, the amount of water required to obtain high fluidity will be significantly large, resulting in a decrease in strength etc. A problem arises.

The antifoaming agent is used to prevent blistering and denting of the floor surface due to foaming.The antifoaming agent used in the present invention includes commonly used silicone-based and nonionic surfactants. Defoamers can be used. The amount of antifoaming agent used is 0
．． 01 to 2 parts by weight, preferably 0.1 to 0.5 parts by weight. If the amount used is less than the above amount, there will be no antifoaming effect, and even if the amount used is more than the above amount, the effect will not change.

As the aggregate, river sand, sea sand, land sand, crushed sand, silica sand, etc. can be used, and for the purpose of weight reduction, perlite, fly ash, etc. can be used alone or in combination with the above sand, etc. The amount of aggregate used is preferably 30 to 300 parts by weight, preferably 60 to 150 parts by weight, although dry sand is preferably used, but wet sand is also acceptable. If the amount used is less than the above, the fluidity will not be maintained for a long time, and if the above is satisfied,
The strength is low and the fluidity is poor.9 The water used is tap water, industrial water, etc. The amount used depends on the composition of other materials and the properties of the target slurry, but 2
It is 5 to 100 parts by weight. If the amount used is less than the above,
High fluidity cannot be obtained, and if it exceeds the above, efflorescence and breathing tend to occur, and strength also decreases.

In the SL material of the present invention, other materials that are generally mixed in cement aqueous compositions, such as shrinkage reducing agents and bulking nails, can be used as long as they do not adversely affect the physical properties. Examples of shrinkage reducing agents include alcohol alkylene oxides and glycol esters. In addition, calcium carbonate, gypsum, fine silica powder, fly ash, etc. can be used as fillers.

<Examples, etc.> Test category 1 (manufacture of dispersant) Manufacture example 1 (manufacture of dispersant A) 60 parts of methacrylic acid (parts by weight, same hereinafter), methoxypolyethylene glycol (number of moles of ethylene oxide added n = 9) 150 parts of monomethacrylate, 250 parts of wood, and 7 parts of 2-mercaptoethanol were charged into a flask.
48% of sodium hydroxide (jlIIk%, same below)
After adding 58 parts of an aqueous solution to neutralize and dissolve uniformly, the temperature of the reaction system was changed to 65°C in a hot water bath with the atmosphere replaced with nitrogen.
50 parts of a 10% aqueous solution of ammonium persulfate was added to start polymerization, and the polymerization reaction was continued for 4 hours until the vinyl monomer remaining in the reaction system was almost consumed. Then, 50 parts of a 10% aqueous solution of 2-mercaptoethanol was added to terminate radicals. The aqueous solution of the binary copolymer obtained by radical termination was purified by precipitation in an impropat tool and dried to obtain a binary copolymer (molecular weight 3700, sulfur content II 1.6%). Next, 200 parts (0,054 mol) of the obtained binary copolymer and 450 parts of water were charged into another flask, and the atmosphere was replaced with nitrogen.

The temperature of the reaction system was maintained at 70°C in a hot water bath, and 30 parts of a 10% aqueous solution of ammonium persulfate was added to radically activate the binary copolymer, followed by a 20% aqueous solution of sodium methallylsulfonate. 80 parts (equivalent to 0.10 mol as sodium methallylsulfonate) was added, and the reaction was continued for 2 hours to complete the radical addition reaction.

After the obtained product was purified by precipitation as described above, it was analyzed and found that the carboxyl value was 152.4 and the O content was 3.1.
%, number average molecular weight was 4000 (GPC method, polyethylene glycol equivalent, same below). From this result, the product was sodium methacrylate/methoxypolyethylene glycol (n=9) methacrylate-70/30 (
Water-soluble vinyl copolymer (dispersion It was agent A).

Production Example 2 (Production of Dispersant B) 870 parts of methacrylic, 101 parts of methoxypolyethylene glycol (n=9) monomethacrylate, 240 parts of water and 6 parts of 2-mercaptoethanol were placed in a flask, and a 48% aqueous solution of sodium hydroxide was added. After adding 67 parts to neutralize and dissolve uniformly, change the atmosphere to nitrogen! ! I tested it. The temperature of the reaction system was maintained at 65°C in a hot water bath, and 30 parts of a 10% aqueous solution of ammonium persulfate was added to initiate polymerization. Polymerization was continued for 4 hours until the vinyl monomer remaining in the reaction system was almost consumed. The reaction continued. Then, 80 parts of a 5% aqueous solution of 2-mercaptoethyl acrylate was added to terminate radicals. The aqueous solution of the binary copolymer obtained by radical termination was purified by precipitation in Improper Tool and dried to obtain a binary copolymer (molecular weight 5200, sulfur content 1.4
%) was obtained. Next, 150 parts (0
350 parts of water were charged into another flask, and the atmosphere was replaced with nitrogen. The temperature of the reaction system was maintained at 70°C in a hot water bath, and 23 parts of a 10% aqueous solution of ammonium persulfate was added to radically activate the binary copolymer, followed by a 20% aqueous solution of sodium methallylsulfonate. 45 parts (0.0 as sodium methallylsulfonate)
057 mol equivalent) was added, and the reaction was continued for 2 hours to complete the radical addition reaction.

After the obtained product was purified by precipitation as described above, analysis revealed that the carboxyl value was 221 and the sulfur content was 2.5.
%, number average molecular weight was 5,500. From this result, the product was sodium methacrylate/methoxypolyethyleneglyfur (n=9 methacrylate), 80/2
A water-soluble vinyl copolymer with 5.5% (corresponding to 1.8 pieces) of sodium methallylsulfonate per molecule of the binary copolymer copolymerized at a ratio of 0 (molar ratio) to the end of the main chain. (
It was dispersant B).

Production Example 3 (Production of Dispersant C) 50 parts of methacrylic acid, 383 parts of methoxypolyethylene glycol (n=9) monomethacrylate, 750 parts of water, and 4 parts of mercaptoacetic acid were charged into a flask, and 48% of a 48% aqueous solution of sodium hydroxide was added. After neutralizing and uniformly dissolving 10% of ammonium persulfate, the temperature of the reaction system, which had been replaced with nitrogen, was kept at 65°C in a hot water bath.
Polymerization was started by adding 40 parts of the aqueous solution, and the polymerization reaction was continued for 5 hours until the vinyl monomer remaining in the reaction system was almost consumed, and then heated and stirred at 90 to 95°C for 1 hour. This was followed by radical termination.

The aqueous solution of the binary copolymer obtained by radical termination was purified by precipitation in an impropat tool and dried to obtain a zero-dimensional binary copolymer (molecular weight 7800, sulfur content 0.3%). , 400 parts (0,051 mol) of the obtained binary copolymer
and 950 parts of water were placed in another flask, the atmosphere was replaced with nitrogen, and the temperature of the reaction system was maintained at 70°C in a hot water bath.
, 35 parts of a 10% aqueous solution of 2''-azobis[2-methyl-N-(2-and droxyethyl)propionamide] was added to radically activate the binary copolymer, and then methallylsulfonic acid was added. 100 parts of a 20% aqueous sodium solution (equivalent to 0.13 mol as sodium methallylsulfonate) was added, and the reaction was continued for 2 hours to complete the radical addition reaction.

After the obtained product was purified by precipitation as described above, analysis revealed that the carboxyl value was 123 and the sulfur content was 0.9.
% and number average molecular weight was 8,000. From this result, the product is sodium methacrylate/methoxypolyethylene glycol (n=9 methacrylate)=80740
A water-soluble vinyl copolymer with 3.1% (corresponding to 1.6 pieces) of sodium methallylsulfonate per molecule of the copolymerized binary copolymer (mole ratio) added to the end of the main chain ( It was dispersant C).

Hereinafter, dispersant D-H was prepared in the same manner as in Production Examples 1 to 3.
The manufacturing conditions of the obtained zero dispersants A-H are summarized in Table 1, and the analytical values are summarized in Table 2.

Table 1 (Manufacturing conditions of dispersant) Note: In Table 1, Type 2 Dispersant type Condition 1: Radical terminator used Condition 2 2 Radical initiator used to radically activate the binary copolymer Agent condition 3: Type and formula of vinyl monomer corresponding to formula (1) (
2) Type of vinyl monomer equivalent and molar ratio of both vinyl monomers (values in the relevant column in Table 1) Condition 4: Formula (3) Type of vinyl monomer equivalent and molar ratio of both vinyl monomers Charge ratio (mol%) to the original copolymer: 1: 2-mercaptoethanol 2: 2-mercaptoethyl acrylate 3: 1.2
-Ethanediol book 4: 3-mercapto-1,2-propanediol book 5: ammonium persulfate zero 6: 2.2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide book 7: methallyl Sodium sulfonate salt Book 8: Allyl sulfonate sodium salt a: Sodium methacrylate salt b = Niacrylic sodium salt C: Sodium crotonate salt d: Metquin polyethylene glycol (n = 9) Methacrylate e: Methoxypolyethylene glycol (n = 23) Methacrylate f: methoxypoly(n=12) ethylene/poly(n=
3) Propylene glycol methacrylate Table 2 (analytical values) Note) In Table 2, 5 types 7. Zero 8: Same analysis value as in Table 1 1: (
Reaction ratio of vinyl monomer corresponding to formula (1)/vinyl monomer corresponding to formula (2): J (mole ratio) Analysis value 2 Formula added to the terminal per molecule of binary copolymer (
3) Percentage and moles of equivalent vinyl monomer Production Comparative Example 1 (Dispersant R-1: 60 parts of methacrylic acid, 150 parts of methoxypolyethylene glycol (n=9) monomethacrylate, 250 parts of water, and 2 -Pour 7 parts of mercaptoethanol into a flask,
After adding 58 parts of a 48% aqueous solution of sodium hydroxide to neutralize it and uniformly dissolving it, the temperature of the reaction system whose atmosphere was replaced with nitrogen was maintained at 65°C in a hot water bath, and 58 parts of a 10% aqueous solution of ammonium persulfate was added. The polymerization reaction was continued for 5 hours to complete the polymerization.

The obtained product was precipitated and purified in Improper Tool, and then analyzed. It was found that the carboxyl value was 175, the number average molecular weight was 4300, and the sodium methacrylate/methoxypolyethylene glycol (n=9) monomethacrylate = 73727 (molar ratio ) A water-soluble vinyl copolymer (dispersant R-1) was obtained.

Comparative Production Example 2 (Synthesis of Dispersant R-2) 52 parts of methacrylic acid, 129 parts of methoxypolyethylene glycol (n=9) monomethacrylate, 48 parts of styrene sulfonic acid sodium salt, 390 parts of water and 7 parts of 2-mercaptoethanol. After charging the flask and adding 50 parts of a 48% aqueous solution of sodium hydroxide to neutralize it and dissolve it uniformly, the temperature of the reaction system in which the atmosphere was replaced with nitrogen was maintained at 60°C in a hot water bath, and the ammonium persulfate solution was added. Polymerization was started by adding 55 parts of a 10% aqueous solution, and the polymerization reaction was continued for 5 hours to complete the polymerization.

The obtained product was precipitated and purified in isopropanol, and then analyzed and found to have a carboxyl value of 140 and a number average molecular weight of 4100, and a copolymerization rate of 18% (copolymer) of sodium styrene sulfonate by UV absorption. A water-soluble vinyl copolymer (dispersant R-2) in which each vinyl monomer was randomly bonded was obtained, with a concentration of 3.5 standard equivalents per molecule.

Comparative Production Example 3 (Synthesis of Dispersant R-3) 60 parts of methacrylic acid, 150 parts of methoxypolyethylene glycol (n=9) monomethacrylate, and 250 parts of water were placed in a flask, and 58 parts of a 48% aqueous solution of sodium hydroxide was added. After neutralizing and uniformly dissolving the atmosphere, the temperature of the reaction system was maintained at 65°C in a hot water bath, and 40 parts of a 10% aqueous solution of ammonium persulfate was added to start polymerization. 20% of methallylsulfonic acid sodium salt was added to the reaction system in which the polymerization reaction continued for an hour without performing any operation for radical termination.
80 parts of an aqueous solution (equivalent to 0.10 mol as methallylsulfonic acid sodium salt) was added, and the reaction was continued for 3 hours.

After the obtained product was purified by precipitation in Improper Tool, it was analyzed and found to have a carboxyl value of 171, a number average molecular weight of 9000, a sulfur content of 0.2% or less, and a copolymerization rate of methallylsulfonic acid sodium salt. A water-soluble vinyl copolymer (dispersant R-3) having a dispersion content of 0.2% (equivalent to 0.1 per molecule of copolymer) was obtained.

Comparative Production Example 4 (Synthesis of Dispersant R-4) 55 parts of methacrylic acid, 160 parts of methoxypolyethylene glycol (n=9) monomethacrylate, 270 parts of water, and 6.5 parts of 2-mercaptoethanol were charged into a flask, and hydroxylated. After adding 53 parts of a 48% aqueous solution of sodium to neutralize it and dissolving it uniformly, the temperature of the reaction system in which the atmosphere was replaced with nitrogen was maintained at 65°C in a hot water bath, and 50 parts of a 10% aqueous solution of ammonium persulfate was added. and start polymerization, 4
The polymerization reaction was continued for hours. Then, 50 parts of a 10% aqueous solution of 2-mercaptoethanol was added to terminate radicals. The obtained aqueous solution of the binary copolymer was purified by precipitation in isopropanol, dried, and analyzed, and the sulfur content was 1.4% and the number average molecular weight was 4800.
Next, 150 parts of the obtained binary copolymer and 350 parts of water were charged into another flask, and the temperature of the reaction system in which the atmosphere was replaced with nitrogen was maintained at 70°C in a hot water bath, and a 10% aqueous solution of ammonium persulfate was added. After adding 30 parts to radically activate the binary copolymer, 100 parts of a 20% aqueous solution of sodium 2-sulfoethyl methacrylate was added, and the reaction was continued for 2 hours to complete the radical addition reaction. .

The obtained product was purified by precipitation in Improper Tool and analyzed, and it was found to have a carboxyl value of 155, a sulfur content of 1.5%, a number average molecular weight of 4800, and a sodium content of 2-2 per molecule of the binary copolymer. A water-soluble vinyl copolymer (dispersant R-4) in which 0.6% of sulfoethyl methacrylate (equivalent to 0.2 sulfoethyl methacrylate per molecule of the binary copolymer) was added to the end of the main chain was obtained.

Comparative Production Example 5 (Synthesis of Dispersant R-5) 15 parts of methacrylic acid, 327 parts of methoxypolyethylene glycol (n=9) monomethacrylate, 550 parts of water, and 9 parts of 2-mercaptoethanol were charged into a flask.
After adding 15 parts of a 48% aqueous solution of sodium hydroxide to neutralize and dissolve uniformly, the temperature of the reaction system was kept at 65°C in a hot water bath with the atmosphere replaced with nitrogen, and a 10% aqueous solution of ammonium persulfate was added. 60 parts were added to start polymerization, and the polymerization reaction was continued for 4 hours. Then, 50 parts of a 10% aqueous solution of 2-mercaptoethanol was added to terminate radicals. The obtained aqueous solution of the binary copolymer was precipitated in isopropanol, dried and analyzed. It was found that the sulfur content was 0.9% and the number average molecular weight was 4500. 200 parts of the original copolymer and 450 parts of water were placed in another flask, the atmosphere was replaced with nitrogen, the temperature of the reaction system was maintained at 70°C in a hot water bath, and 30 parts of a 10% aqueous solution of ammonium persulfate was added. After radically activating the binary copolymer, 80 parts of a 20% aqueous solution of methallylsulfonic acid sodium salt was added, and the reaction was continued for 2 hours.
The radical addition reaction was completed.

The obtained product was purified by precipitation in Improper Tool, and then analyzed, and found to have a carpogycyl value of 27, a sulfur content of 20%, and a number average molecular weight of 4,800. From this result, the product is sodium methacrylate/methoxypolyethylene glycol (n=9) methacrylate=20/8
0 (molar ratio) of polymerized sodium methallylsulfonate per molecule of the binary copolymer (1.(34[!I phase) per molecule of the binary copolymer). A water-soluble vinyl copolymer (dispersant R-5) in which the main chain was added at the end was obtained.

Test Category 2 (Manufacture of SL material and comparison of physical properties of SL materials due to differences in dispersants) Using the dispersant manufactured in Test Category 1 and conventional lignin-based, naphthalene-based, melamine-based, and carboxylate-based dispersants, SL material was manufactured. Table 3 shows the formulation of each material.

Table 3 (Blending ratio of SL material) In Table 3, the cement used is ordinary Portland cement made by Onoda Cement, the aggregate is Yamagata silica sand (F, M = 2.3), and the 11 tension material is Onoda. Onoda Expan manufactured by Cement Co., Ltd. The water retention agent is Metrose (molecular weight 8000) manufactured by Shin-Etsu Chemical Co., Ltd., and the antifoaming agent is S N manufactured by Sannopco Corporation.
-Tiformer-.

Regarding the types of dispersants in Table 3, A is HR-100 manufactured by Dezumi Kokusaku Pulp Co., Ltd. as a lignin-based agent, Mighty 2000WH manufactured by Kao Corporation as a naphthalene-based agent, and SMF-PG manufactured by 8 San Kagaku Co., Ltd. as a melamine-based dispersant. In the second case, Aqualock FC-600 manufactured by Nippon Shokubai Kagaku Co., Ltd. was used as the carboxylic acid salt system.

Each material is rotated at high speed in a Hobart mixer with a capacity of 21M for 2
For the slurry obtained by kneading for minutes, the flow change over time, the J-roath change over time, the setting test, and the compressive strength at 7-day and 28-day ages.

Surface strength tests were conducted on 14-day and 28-day wood samples, and length change tests were conducted on 3-day and 28-day wood samples. All tests were conducted at 20°C using the method described below. The test results are shown in Table 4-1 and Table 4-2.

Test method/Flow test SL material slurry was packed into a flow cone with an inner diameter of 50 m5 and a height of 50°C, the cone was pulled up, and the diameter of the spread was measured when the composition stopped spreading.

Changes over time in the fist flow test In the tests 3.0 hours, 4, 5 hours, and 6.0 hours after kneading, the slurry was stored in a static state until the measurement was taken, and the slurry was collected using a kneading spoon. The mixture was kneaded for about 1 minute and the above flow test was conducted.

・J-Roth test Conducted in accordance with Consistency Test Method (Draft) 17 of the Japan Society of Civil Engineers "Industrial Materials Standards Handbook (Based on the Japan Society of Materials Science)". J
- A funnel with an inner diameter of 10+*m was used.

- Time-dependent change in J-funnel test 3.0 hours, 4.5 hours, and 6.0 hours after kneading, the J-funnel test was conducted in the same manner as the flow test.

・Setation test, compressive strength test, length change test JIS-R-
5201.

A flat steel plate with a surface strength of 40 × 40 layers was attached to the surface of the cured SL material using an epoxy adhesive, and the plate was pulled using a hydraulic jack until it peeled off, and the maximum tensile force was measured.

Table 4-1 (Physical property test results) Table 4-2 (Physical property test results) First, the SL of the present invention using the dispersant produced from the production example
A comparison will be made between the material and the SL material using a dispersant manufactured in a manufacturing comparative example.

Looking at the changes over time in the flow value and J-Roth value, the SL material of the present invention shows better values in both flow value and J-Roth value than the comparative example. Looking at the change in flow over time, the SL material of the present invention has a stable flow value around 220s+s from the time of kneading until 6 hours later. On the other hand, in the comparative example, the flow value decreased from 4.5 hours to 6 hours.

Looking at the change in J-Roth value over time, the SL material of the present invention has
Compared to the J-roth value at the time of kneading, the value after 6 hours is 2.
It has increased by about 0 seconds. On the other hand, the SL material of the comparative example is already about 10 seconds higher at the time of kneading than the SL material of the present invention, and about 30 to 40 seconds higher after 6 hours. As the J-Roth value increases, the viscosity of the slurry increases, resulting in poor workability.

Next, a comparison will be made between the SL material of the present invention and the SL material using a general dispersion material that has been conventionally used for SL materials.

Looking at the change in flow value over time, two types of materials were able to maintain high fluidity up to 6 hours after kneading: the SL material of the present invention and the SL material using a carboxylate-based dispersant.

On the other hand, when looking at the setting time, only the SL material using a carboxylate-based dispersant showed the initial onset.

Both completion times exceeded 20 hours, especially the completion time exceeded 24 hours. Therefore, if an SL material with a carboxylate-based dispersant is used, it is considered difficult to work on the floor the next day. On the other hand, the SL material of the present invention maintains high fluidity for a long time, and both the initial and final setting times are much shorter than 20 hours. It has the advantage of being durable enough to withstand use even after a long period of time, and being reliably cured the next day, allowing for other work to be carried out.

Test Category 3 (Production of SL material and SL material physical properties) Using the dispersant B obtained from Production Example 2 above as the dispersant and using the same materials as in Test Category 2, An SL material was manufactured using the blending ratio. For each SL material, test category 2
The results of physical property tests conducted in the same manner as above are shown in Tables 6-1 and 6-2. All tests were conducted at 20"C.

Table 5 (Blending ratio of SL material) Table 6-1 (Physical property test results) Table 6-2 (Physical property test results Examples 9 to 11 are those in which the amount of dispersant added was changed. The time to maintain possible fluidity increases as the amount added increases.The setting time also increases as the amount added increases.
Since it takes less than 4 hours, it is possible to work on the floor the next day after pouring the SL material.

Example 10.12.13 shows the cement aggregate ratio (hereinafter C/S
). When C/S is high, it becomes difficult to maintain high fluidity for a long time, and C/S
If C/S is low, a high flow value cannot be obtained, but the strength of a member whose fluidity does not change for a long time increases as C/S increases.

In Examples 1O114 and 15, the amount of expansion material in the SL material was changed. Looking at the length change rate, Example 10 is almost 0, Example 14 is less than 10, and Example 15 is +
It is around 10. If the length change rate exceeds +1O, there is a risk of cracking due to expansion, extrusion of partitions, etc., and destruction. If the length change rate is less than -lO, cracks may occur due to drying shrinkage.

Test category 4 (SL material manufacturing and SL material physical properties) Capacity 0.35
The materials used in Example 1 were weighed out in a mortar mixer of m3 according to the formulation shown in Table 7, and kneaded at a rotation speed of 1 t (300 rpm) for 10 minutes to produce a 1 m SL material slurry.

The fluidity at the end of kneading was a J-Roth value of 35 seconds and a flow value of 3701. The temperature at this time was 30℃ and the humidity was about 4
It was 0%.

The obtained slurry was put into a 7 gitator car, and after 5 hours had elapsed from the end of kneading at a drum rotation speed of 0.7 rpm, it was poured on a warehouse floor. The base of the floor is made of mortar, and an acrylic primer is applied to the base to prevent water from entering the floor. The fluidity of the SL material at the time of casting was a J-Roth value of 35 seconds and a flow value of 360 seconds. The temperature at the time of pouring was 32℃
, the humidity was about 40%. Even after curing, a smooth floor surface could be formed without any cracks or the like. In addition, when the slurry was taken and tested immediately after kneading, the compressive strength at 28 days old was 320 Kg/cm', and the surface strength at 14 days old was 17,0 Kg/cs2.

Table 5 (Blending ratio of SL material) <Effects of the invention> According to the present invention, the cement dispersant used in the blend contains carboxyl groups or salts thereof, glycol esters, and especially sulfone at the end of the main chain in the vinyl copolymer. Because it has three types of parent wood groups, acid groups or salts thereof, when compared to dispersants whose main component is carboxylic acid, it has the same or higher performance in maintaining high fluidity for a long time, and Moreover, it is possible to produce an SL material with a significantly shortened setting time. In addition, because the setting time is short, it is possible to use larger amounts of components that delay the setting effect of cement compositions, such as water retention agents, water, and dispersants, than in conventional products. It is possible to avoid a decrease in surface strength due to the phenomenon that the floor surface becomes crumbly under high temperature conditions in summer.
An SL material with stable physical properties even under environmental changes can be obtained.

In addition, according to the present invention, high fluidity can be maintained for a long time, and the setting and hardening after pouring is slow, so long-distance transportation is possible. The work can be done much faster than with conventional methods.

Patent applicant: Onoda Cement Co., Ltd. Takemoto Oil Co., Ltd. Agent: Hiroshi Yama, Patent Attorney

Claims (1)

[Claims] 1. 1 to 20 parts by weight of expansion agent, 0.01 to 7 parts by weight of water retention agent, 0.01 to 2 parts by weight of antifoaming agent, and 30 to 300 parts by weight of aggregate per 100 parts by weight of cement. 25 to 100 parts by weight of water, and 0.05 to 2 parts by weight of a dispersant, the dispersant being a vinyl monomer represented by the following formula (1). mass and the following formula (2
) and vinyl monomer represented by formula (1)/vinyl monomer represented by formula (2) = 50/5.
After copolymerizing in the presence of a radical initiator at a ratio of 0 to 95/5 (molar ratio), a binary copolymer is obtained by radical termination, and then a radical initiator is added to the binary copolymer. In addition, after forming a radically activated binary copolymer, one or more vinyl monomers represented by the following formula (3) are radically added to the radically activated binary copolymer. A self-leveling cement aqueous composition, which is a water-soluble vinyl copolymer having a sulfonic acid group at the end of the main chain, which is produced by adding a sulfonic acid group to the end of the main chain. Formula (1): ▲There are mathematical formulas, chemical formulas, tables, etc.▼ Formula (2): ▲There are mathematical formulas, chemical formulas, tables, etc.▼ Formula (3): ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [Formula (1) ~(3), R^1~R^5, R^7 are simultaneously the same or different, H
Or CH_3. R^6 is an alkyl group having 1 to 3 carbon atoms. X and Y are alkali metals, alkaline earth metals, ammonium or organic amines. n is an integer from 5 to 25. ] 2. The dispersant is the end of the main chain produced by adding a compound having at least two active hydrogen groups such as a hydroxyl group or a thiol group in the molecule to perform radical termination in the production of a water-soluble vinyl copolymer. The self-leveling cement aqueous composition according to claim 1, which is a water-soluble vinyl copolymer having sulfonic acid groups. 3. The dispersant is a main chain produced by adding a compound that shares a thiol group and an α,β-unsaturated hydrocarbon group in the molecule to radically terminate the water-soluble vinyl copolymer. The self-leveling cement aqueous composition according to claim 1, which is a water-soluble vinyl copolymer having a sulfonic acid group at the end. 4. The dispersant contains sulfone at the end of the main chain, which is produced by adding an azobis compound having a hydroxyl group in the molecule to form a radically activated binary copolymer in the production of a water-soluble vinyl copolymer. The self-leveling cement aqueous composition according to claim 1, which is a water-soluble vinyl copolymer having acid groups. 5. The self-leveling cement aqueous composition according to claim 1, 2, 3 or 4, wherein the dispersant is a water-soluble vinyl copolymer having a molecular weight of 2,000 to 15,000 and having a sulfonic acid group at the end of the main chain.