JPS59203742A - Self levelling gypsum aqueous composition - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to self-leveling gypsum aqueous compositions.

A technology that forms a highly smooth floor surface by pouring a gypsum-based or cement-based slurry onto the floor surface of a building that has self-smoothness, that is, the property of forming a smooth surface under the action of gravity. Also known as the Naganebe Beni method,
Already known.

This flow-on beni method does not require any special skill,
It has been widely used in recent years because it makes it possible to form a highly smooth floor surface.

The present invention relates to the improvement of a gypsum-based slurry having self-leveling properties (hereinafter referred to as a self-leveling gypsum aqueous composition).

The self-leveling gypsum aqueous composition is generally used to form a highly smooth floor by pouring it onto the floor of a building, as described above. However, since this floor surface is usually formed on a base made of concrete or the like, the requirements for strength are not very strict. Rather, the gypsum aqueous composition is required to have characteristics that allow it to easily form a highly smooth floor surface without requiring special skill.

Therefore, in order to form a highly smooth floor surface using a gypsum aqueous composition without requiring any skill, (1) the gypsum aqueous composition must have high fluidity, that is, a high flow value; (2) The high flow value of the mixed and prepared gypsum aqueous composition remains at a high level without decreasing much even after a certain period of time (assuming the time required for construction operations), that is, the self-leveling property is high. (3) After being poured onto the floor, it is particularly required that the water and solids be separated, that is, that the water floating phenomenon is unlikely to occur.

Generally, the above characteristics are imparted by incorporating a gypsum dispersant into the composition.

Conventional dispersants for gypsum include, for example, ligninsulfonic acid n, salts of gluconic acid and glucoheptonic acid, naphthalenesulfonic acid/formalin condensate salt, melamine φ formalin condensate sulfonate, polysaccharide/calcium chloride/ Many types are known, including triethanolamine, and each is used for a variety of purposes depending on its characteristics. However, when these known gypsum dispersants are used in gypsum aqueous compositions for the casting method, in general, if high fluidity is to be imparted, curing tends to be delayed, and mixing and preparation is difficult. The flow value of the aqueous gypsum composition tends to decrease rapidly over time.

The present invention uses a novel gypsum dispersant to provide a self-leveling gypsum aqueous composition that has various required properties at a high level.

Conventionally, one of the typical compositions of self-leveling gypsum aqueous compositions is gypsum as a hardening component, aggregate, antifoaming agent, gypsum dispersant, and if necessary, cement and viscosity modifier. Aqueous gypsum compositions are known, in which a suitable amount of water is added. The present invention utilizes a composition system obtained by blending a new gypsum dispersant in a specific ratio in such a composition system, thereby achieving the high flow value and excellent properties required for a self-leveling gypsum aqueous composition. The present invention provides an aqueous gypsum composition that has excellent self-leveling properties and eliminates the phenomenon of water floating.

That is, the present invention is a gypsum aqueous composition containing gypsum, aggregate, a gypsum dispersant, an antifoaming agent, and water, wherein the gypsum dispersant is polyalkylene glycol mono(meth).
It is a (meth)acrylic acid copolymer containing a structural unit derived from an acrylic acid ester monomer and a structural unit derived from a (meth)acrylic acid monomer, and the amount of the gypsum dispersant is determined by the following formula: % formula %) () () n: Content (parts by weight) of structural units derived from (meth)acrylic acid monomers in the gypsum dispersant m: Polyalkylene glycol mono(meth)acrylic in the gypsum dispersant The content (parts by weight) of structural units derived from acid ester monomers is such that the content (parts by weight) of gypsum and aggregate is such that the ratio of aggregate to 100 parts by weight of gypsum is 10 to 10 parts by weight. 300 parts by weight, and the amount of water blended is 20 to 80% by weight based on the amount of gypsum (however, as gypsum, α
When using type hemihydrate gypsum, β type hemihydrate gypsum, or ■ type anhydrite, the amount of water added should be 20 to 50% by weight, 35 to 80% by weight, or 25 to 55% by weight, respectively. (preferably), and the amount of antifoaming agent added is 0.0 based on the total amount of gypsum and aggregate.
1 to 1.0% by weight, and a self-leveling gypsum aqueous composition characterized in that the flow value of the gypsum aqueous composition is 150 mm or more.

Next, the present invention will be explained in detail.

The present invention provides polyalkylene glycol (
A gypsum dispersant whose main component is a (meth)acrylic acid copolymer containing a structural unit derived from a meth)acrylic acid ester monomer and a structural unit derived from a (meth)acrylic acid monomer is used. However, the (meth)acrylic acid copolymer has the general formula: % formula % [However, R1 represents hydrogen or a methyl group, R2 represents an alkylene group having 2 to 4 carbon atoms, and R3 represents hydrogen or a carbon number represents 1 to 5 alkyl groups, and p represents an integer of 1 to ioo] Structural unit (a) derived from a polyalkylene gelicol mono(meth)acrylic acid ester monomer represented by the general formula : % formula % [However, R4 represents hydrogen or a methyl group, X is hydrogen,
・Represents a valent metal, a divalent metal, an ammonium group or an organic amine group] Constituent units (b) derived from (meth)acrylic acid monomers, and copolymerizable with these units The structural unit (c) derived from nanatsuma is composed of 10 to 95% by weight of (a), 90 to 5% by weight of (b), and 0 to 50% by weight of (c) (however, ), (b) and 1 (c), the total of which is 100% by weight.

More preferably, the polyalkylene gellicol mono(
50 to 80% by weight of the structural unit (a) derived from a meth)acrylic acid ester monomer, and 2% of the structural unit (b) derived from the (meth)acrylic acid monomer.
It is a (meth)acrylic acid copolymer containing 0 to 50% by weight (however, the total amount of both is 100% by weight).

The above (meth)acrylic acid copolymer can be produced by the following method.

That is, a polyalkylene gelicol mono(meth)acrylic acid ester monomer (hereinafter referred to as monomer (I)) represented by the general formula (1): 4 CH2= CCOOX (IF
) (hereinafter referred to as monomer (II)), [However, in general formula (I) and general formula (II), R
I, R2, R3, R4, X, and p have the same meanings as above.

In addition, in the above-mentioned copolymerization, the amount of less than 50 double stars based on the superposition of all the monomers used, and -1- (
As long as it does not interfere with the water solubility of the meth)acrylic acid copolymer, a monomer capable of copolymerizing with F+f (hereinafter referred to as monomer (III)) can be used in combination with the monomers listed below.

In addition, when the copolymer obtained by the copolymerization described in I- contains an acid, (), it can be used after being suitably neutralized with an alkali.

! Monomer (I) used to obtain the (meth)acrylic acid copolymer described in - can be obtained by a known method. Examples of monomer (II) include polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, polybutylene glycol mono(meth)acrylate, methoxypolyethylene glycol mono(meth)acrylate, and methoxypolypropylene glycol mono(meth)acrylate. Examples include meth)acrylate, methoxypolybutylene glycol mono(meth)acrylate, ethoxypolyethylene glycol mono(meth)acrylate, ethoxypolypropylene glycol mono(meth)acrylate, and ethoxypolybutylene glycol mono(meth)acrylate. One type or two or more types can be used.

Further, examples of 7-mer (n) include acrylic acid, methacrylic acid, and their -valent metal salts, divalent metal salts, ammonium salts, and organic amine salts, and one or two of these More than one species can be used.

The monomer (Iff) is a monomer that can be copolymerized with the monomer (I) and the monomer (II), and examples of this monomer (Iff) include aliphatic alcohols having 1 to 20 carbon atoms and Esters with (meth)acrylic acid - (meth)
Acrylamide; 71/yne alcohol, fumaric acid, or these acids and an aliphatic alcohol having 1 to 20 carbon atoms, a glycol having 2 to 4 carbon atoms, or a polyalkylene glycol having an addition mole of 2 to 100 of these glycols. monoesters or diesters; acetic acid alkenyl esters such as vinyl acetate and propenyl acetate; styrene,
Aromatic vinyls such as p-methylstyrene and styrene sulfonic acid; vinyl chloride;
A species or two or more species-1- can be used.

To produce the (meth)acrylic acid copolymer,
The above monomer components may be copolymerized using a polymerization initiator by a known method. Copolymerization can be carried out by methods such as polymerization in a solvent or bulk polymerization.

5 Polymerization in a solvent can be carried out either batchwise or continuously, and the solvents used include water; lower alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; benzene, toluene, xylene, cyclohexane, Examples include aromatic or aliphatic hydrocarbons such as n-hexane; ethyl acetate; and ketone compounds such as acetone and methyl ethyl ketone. In view of the solubility of the raw material monomer and the obtained (meth)acrylic acid copolymer, and the ease of use of the copolymer, at least one selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms should be used. is preferred. Among the lower alcohols having 1 to 4 carbon atoms, methyl alcohol, ethyl alcohol, and isopropyl alcohol are particularly advantageous.

When polymerization is carried out in an aqueous medium, a water-soluble polymerization initiator such as ammonium or alkali metal persulfate or hydrogen peroxide is used as the polymerization initiator. At this time, an accelerator such as sodium hydrogen sulfite can also be used in combination. In addition, for polymerization using lower alcohols, aromatic hydrocarbons, aliphatic hydrocarbons, ethyl acetate, or ketone compounds as solvents, peroxides such as benzoyl peroxide and lauroyl peroxide; hydroperoxides such as cumene hydroperoxide, etc. Oxide: Aliphatic azo compounds such as azobisisobutyronitrile are used as polymerization initiators. At this time, a promoter such as an amine compound can also be used in combination. Furthermore, when a water-lower alcohol mixed solvent is used, it can be appropriately selected from among the various types of polymerization initiators or combinations of polymerization initiators and accelerators mentioned above. The polymerization temperature is appropriately determined depending on the solvent and polymerization initiator used, but is usually 0-
It is carried out within a range of 120°C.

In bulk polymerization, peroxides such as benzoyl peroxide and lauroyl peroxide; hydroperoxides such as cumene hydroperoxide; and aliphatic azo compounds such as azobisisobutyronitrile are used as polymerization initiators.
It is carried out in a chamber at a temperature of 50-150°C.

The (meth)acrylic acid-based copolymer thus obtained can be used as the main component of a gypsum dispersant as it is, but if necessary, it can be further neutralized with an alkaline substance and then used as a gypsum dispersant. It may also be used as a main component. Preferred examples of such alkaline substances include hydroxides, chlorides, and carbonate salts of -valent metals and divalent metals; ammonia; and organic amines.

Further, the molecular weight of the (meth)acrylic acid copolymer can be in a wide range, but it is preferably in the range of 500 to 50,000.

(Meth)acrylic acid copolymers can be used alone or as a mixture of copolymers having various structures as a gypsum dispersant.

As mentioned above, the gypsum dispersant of the (meth)acrylic acid copolymer is added to the gypsum aqueous composition of the present invention according to the following formula: Blend amount (parts by weight) n: Content (parts by weight) of structural units derived from (meth)acrylic acid derivatives in the gypsum dispersant m: Polyalkylene glycol mono(meth)acrylic in the gypsum dispersant The content (parts by weight) of structural units derived from acid ester-based hexamers is blended in an amount that satisfies the following.

In other words, when the amount of the gypsum dispersant is in a relationship that satisfies the above formula, the self-leveling gypsum aqueous composition has the high flow value and excellent self-leveling properties required for a self-leveling gypsum aqueous composition. , and exhibits excellent properties such as eliminating the water floating phenomenon. In addition, it is more preferable that the second limit value of the above formula is 0.6 or less.

There are no particular restrictions on the gypsum that can be used in the composition of the present invention, and for example, various types of gypsum such as α-type hemihydrate gypsum, β-type hemihydrate gypsum, and 9-type anhydrite can be used.

Further, the self-leveling gypsum aqueous composition of the present invention may further contain cement in an amount of 40% by weight or less based on the gypsum.

Generally, dispersants having carboxyl groups strongly adsorb onto gypsum particles, thereby effectively dispersing these particles in water. However, due to their strong adsorption properties, they tend to impede the hydration reaction and, as a result, significantly retard curing.

On the other hand, in the gypsum dispersant used in the present invention, the main component (meth)acrylic acid copolymer has in one molecule a nonionic parent wood group called an ethylene oxide compound and an anionic carboxyl group. The hydrophilicity and steric hindrance of the former suppresses the adsorption of the latter to gypsum particles, and as a result, compared to conventional dispersants with carboxyl groups, it has less setting retardation effect and exhibits excellent dispersion performance. considered to be a thing. However, this explanation is hypothetical, and composition 0 of the present invention is not limited thereby.

Aggregate, which is an essential component of the present invention, is a component necessary for imparting strength to the formed gypsum hardened body.

Aggregates are well known as gypsum compounding agents or cement compounding agents, and include, for example, river sand, mountain sand, standard sand, silicic acid, silica powder, slag, calcium carbonate, etc. In some cases, wood flour, perlite, whitebait balloons, fly ash, etc. are used alone or in combination with the above-mentioned sand.

The antifoaming agent contained in the composition of the present invention is effective in suppressing and destroying air bubbles that are likely to be formed by air mixed in during the mixing and preparation of the aqueous composition of the present invention. It is a practical and essential component for the self-leveling gypsum aqueous composition of the present invention which requires a high degree of smoothness. Various antifoaming agents are known, such as alcohol-based, fatty acid ester-based, surfactant-based, and silicone-based antifoaming agents, and in the present invention, an appropriate selection from these antifoaming agents can be used. The blending amount of the antifoaming agent is 0.01 to 1.0% by weight based on the total amount of gypsum and aggregate.

The self-leveling gypsum aqueous composition of the present invention preferably further contains a viscosity modifier, an expansion inhibitor, a setting modifier, and the like.

As the viscosity modifier, known methylcellulose, carboxymethylcellulose, hydroxyethylcellulose,
Natural rubber, polyvinyl alcohol, various polymer emulsions, etc. can be used. The amount of viscosity modifier used varies widely depending on the material used and the desired viscosity. Therefore, it is difficult to specify the amount to be used, but the viscosity of the self-leveling gypsum aqueous composition of the present invention is 600 to 2000.
It is desirable to use the amount in centipoise (measured value using a B-type viscometer).

The expansion inhibitor has the function of suppressing the expansion that occurs when gypsum hardens, and for example, borax or an alkali metal sulfate such as potassium sulfate or sodium sulfate is used. In addition, various phosphates,
Various carboxylic acids, proteins, etc. are used.

Furthermore, other common gypsum aqueous composition formulation materials can be blended as long as they do not interfere with the properties of the self-leveling gypsum aqueous composition of the present invention.

The self-leveling gypsum aqueous composition of the present invention has the above-mentioned properties necessary for forming a highly smooth floor surface without requiring any skill, namely, high flow value, excellent self-leveling property, and water floating. Shows excellent properties in eliminating phenomena. For example, when considering practical performance as a self-leveling gypsum aqueous composition, the required 150 m
Flow values of less than m-1- can be easily obtained, and 180 m
An aqueous M1 composition with a high flow value of 1-1 m or even 200 mm or more can be easily obtained, while the water floating phenomenon hardly appears. Note that the “flow<
"a" means placing a flow cone (vinyl chloride pipe: capacity approximately 100 m, inner diameter 5.1 cm x height 4.75 cm) on -1- of a horizontal vinyl chloride board, pouring the measurement sample into it, and immediately Flow 3 refers to the value obtained by removing the cone and measuring the diameter (two points on the diagonal) 3 minutes later.

In addition, the aqueous gypsum composition of the present invention has a high flow value at the time of mixing and preparation, and remains high even after a certain period of time (assuming the time required for construction operations, usually 30 minutes) does not decrease much. A major feature is that it has high self-leveling properties. That is,
A gypsum aqueous composition with low self-leveling properties loses fluidity within a short time after mixing and preparation, making it difficult to perform the smooth casting method, and even if casting is possible, it is difficult to obtain. It is difficult to provide sufficient smoothness to the floor surface.

Specifically regarding the self-leveling property of the self-leveling gypsum aqueous composition of the present invention, the ratio (F 30 / F.

: hereinafter referred to as SL value) is 0.65 or more, and furthermore, by adjusting the blending amount, 0.8 or more can be easily obtained. An aqueous gypsum composition having such a high SL value is very preferable for practical use because it facilitates the pouring operation and the formed floor surface exhibits high smoothness. Note that ff used in the present invention
5L value" means a value measured by the following method.

A long box-shaped container (length 650 mm) with a rectangular cross section (width 25 mm x length 27 mm) with a "weir (-1-lower movable partition)" located 150 mm from one end. Prepare an SL measuring device arranged as follows, and put 100 ml of a measurement sample into one side (short side) of each container. - Immediately remove the weir of the wooden container and measure the length of the sample flowing. This value is taken as the flow characteristic (FO) at the time of mixing and preparation. The weir of the other wooden container is removed after 30 minutes, and the length of the sample that has flowed is also measured. This value is taken as the flow characteristic (F2O) after 30 minutes, and F 30 /Fo is calculated from these values, and this is taken as the SL value.

Next, the present invention utilizes the above-mentioned (meth) which is the main component of the gypsum dispersant.
This will be explained in more detail with reference to production examples of acrylic acid copolymers, examples of gypsum aqueous compositions, and comparative examples. Note that the numbers of each copolymer used as a gypsum dispersant in the Examples and Comparative Examples shown below correspond to the numbers of each Production Example below.

In addition, hereinafter, unless otherwise specified, "r part" means "part by weight" and r%J means "wt%". In addition, n/m is the content ratio (weight ratio) of the structural units derived from the (meth)acrylic acid monomer and the structural units derived from the polyethylene glycol (meth)acrylic acid ester monomer in the copolymer. represent.

[Production Example 1 of (meth)acrylic acid copolymer] 443 parts of water was charged into a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a gas introduction tube, and a reflux condenser, and the inside of the reaction vessel was heated with nitrogen while stirring. It was then heated to 95° C. in a nitrogen atmosphere.

Next, methoxypolyethylene glycol monomethacrylate (average number of added moles of ethylene oxide: 10)
140 parts, 60 parts of sodium methacrylate and 30 parts of water
0 parts of a 7-mer mixed solution and 47.6 parts of a 5% ammonium persulfate aqueous solution were each added over 120 minutes, and after the addition was complete, 9.6 parts of a 5% ammonium persulfate aqueous solution was added over a period of 20 minutes. After completing the addition of the Motsumer mixed solution, the temperature was maintained at 95°C for 120 minutes to complete the polymerization reaction, and the copolymer (1) [n/m=3/7] was converted into (
It's given.

The pH of a 40% aqueous solution of this copolymer (1) was 7.1, and the viscosity (measured with a B-type viscometer, 25° CC 160rp) was 345 cpS.

[Production Example 21 of (meth)acrylic acid copolymer 453 parts of water was charged into a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a gas introduction tube, and a reflux condenser, and the inside of the reaction vessel was replaced with nitrogen while stirring. and heated to 95°C in a nitrogen atmosphere.

Next, 160 parts of methoxypolyethylene glycol monomethacrylate (average addition mole IQIO of ethylene oxide), 40 parts of sodium methacrylate, and 3 parts of water
00 parts of a monomer mixed solution and 38.9 parts of a 5% ammonium persulfate aqueous solution were each added over 120 minutes.
After the addition was completed, 7.8 parts of a 5% ammonium persulfate aqueous solution was further added over 20 minutes. After the addition of the monomer mixture solution was completed, the temperature was maintained at 95° C. for 120 minutes to complete the polymerization reaction to obtain copolymer (2) [n/m=2/8].

The pH of a 40% aqueous solution of this copolymer (2) was 7.2, and the viscosity (measured with a B-type viscometer, 25° CC 160rp) was 227 cps.

[Example of production of (meth)acrylic acid copolymer 3 parts Isopropyl alcohol (hereinafter referred to as IPA)-water azeotropic composition was placed in a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a gas introduction tube, and a reflux condenser. (IPA/water = 87.
4/12.6 (weight ratio) (the same applies hereinafter) was charged, the inside of the reaction vessel was replaced with nitrogen while stirring, and heated to the boiling point in a nitrogen atmosphere. Next, 131 parts of methoxypolyethylene glycol monomethacrylate (average number of added moles of ethylene oxide: 9), 69 parts of methacrylic acid,
A mixture of 4.5 parts of benzoyl peroxide and 300 parts of an IPA-water azeotrope was added over 120 minutes, and after the addition was complete, 0.9 parts of benzoyl peroxide was added to the IPA-water azeotrope. A dispersion in 10 parts of the boiling composition was added in two portions every 30 minutes. After the addition of the seven-mer mixture was completed, the temperature was maintained at the boiling point for 120 minutes to complete the polymerization reaction. Thereafter, complete neutralization was performed with an aqueous sodium hydroxide solution, and IPA was distilled off to obtain copolymer (3) [n/m = 4/6].

The pH of a 40% aqueous solution of this copolymer (3) was 9.5, and the viscosity (measured with a B-type viscometer, 25° CC 160rp) was 426 cps.

[Example of production of (meth)acrylic acid copolymer 4 parts IPA-water azeotropic composition 486 was placed in a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a gas introduction tube, and a reflux condenser.
The inside of the reaction vessel was purged with nitrogen while stirring, and heated to the boiling point in a nitrogen atmosphere. Next, 148 parts of methoxypolyethylene glycol monomethacrylate (average number of added moles of ethylene oxide: 10), 52 parts of methacrylic 8 acid, 3.6 parts of benzoyl peroxide, and IP
A - 1,000 parts mixture of 300 parts of water azeotrope
The mixture was added in 20 minutes, and after the addition was completed, 0.7 parts of benzoyl peroxide dispersed in 10 parts of the IPA-water azeotropic composition was added in two portions every 30 minutes. After the addition of the mixture was completed, the temperature was maintained at the boiling point for 120 minutes to complete the polymerization reaction. After that, calcium hydroxide 22
An aqueous dispersion of calcium hydroxide in which 4 parts of IPA was dispersed in 201.6 parts of water was added, IPA was distilled off, and the copolymer (4 parts of
) [n/m=3/7] was obtained.

The pH of a 40% aqueous solution of this copolymer (4) was 7.0, and the viscosity (measured with a B-type viscometer, 25° CC 160rp) was 458 cps.

[Example of production of (meth)acrylic acid copolymer 5 parts IPA-water azeotropic composition 487 was placed in a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a gas inlet pipe, and a reflux condenser.
The inside of the reaction vessel was purged with nitrogen while stirring, and heated to the boiling point in a nitrogen atmosphere. Next, from 166 parts of methoxypolyethylene glycol monomethacrylate-1 (10 moles of iF homogeneous addition of ethylene oxide), methacrylic M34 m, 2.9 parts of benzoyl peroxide, and 300 parts of IPA-water co-clearing composition. After addition, 0.6 parts of benzoyl peroxide dispersed in 10 parts of IPA-water azeotrope was added in two portions every 30 minutes. added. After the addition of the mixture was completed, the temperature was maintained at the boiling point for 120 minutes to complete the polymerization reaction. Thereafter, an aqueous calcium hydroxide dispersion in which 14.6 parts of calcium hydroxide was dispersed in 131.7 parts of water was added, and IPA was distilled off to form copolymer (5)' [n/m = 2/8] I got it.

The pH of the 40% aqueous solution of this copolymer (5) was 7.0, and the viscosity (measured using a B-type viscometer, 25°C, 160rp) was 338 cps.

[Example 1] A gypsum aqueous composition having the following composition was prepared.

Phosphate gypsum (Brain value: 2000-2200) 70
1 part Ordinary Portland cement 3 parts Aggregate (new special No. 6 silica sand: manufactured by Ube Denki Kagaku ■) 30 parts Borax
0.2 parts gypsum dispersant [copolymer (
1) n/m = 3/7] Quantities shown in Table 1: Viscosity modifier (Himetrose #30000: manufactured by Shin-Etsu Chemical ■) 0.07 parts Antifoaming agent (SN Deformer 14HP: manufactured by Sannopco ■) 0. 05 parts Antifoaming agent (Formaster PC: manufactured by San Ibuco ■) 0.10 parts Potassium sulfate
0.1 part water
The flow value and SL value of the gypsum aqueous composition mixed and prepared according to the formulation shown in "About 23 Parts" were measured and shown in Table 1. In addition, the presence or absence of slag during the work of pouring and spreading the gypsum aqueous composition was investigated, and this is also shown in Table 1.

1 Table 1 Copolymers L value Flow value SL value Slag 0.2
Part 0.12 186 1.0 No 0.4 part 0
．． 25 198 0.94 No 0.6 part 0.37
2230.93 No 0.8 part 0.49 235 0.85 No annotation:
L value = Amount of gypsum dispersant mixed X (n7m)
A gypsum aqueous composition was prepared in the same manner as in Example 1, except that the composition was changed to [n/m = 2/8] and the blending amount was varied by 5, and the same measurements were performed. The results obtained are shown in Table 2.

Margin below 2 Table 2 Copolymer L value Flow value SL value Slag 0.6
Part 0.21 152 1.6 No 0.8 part 0
．． 29 178 1.5 No 1.0 copy 0.36
206 1.2 No 1.2 copies 0.43 2
13 0.9 None [Example 31 In Example 1, the gypsum dispersant was replaced with copolymer (3)
A gypsum aqueous composition was prepared in the same manner as in Example 1, except that the composition was changed to [n/m = 4/6] and the blending amount was varied, and the same measurements were performed. The results obtained are shown in Table 3.

Table 3 with blank space below Copolymer L value Flow value SL value Slag 0.1
Part 0.10 193 0.94 No 0.2 part 0
．． 19 203 1.0 No 0.4 copy 0.39
219 1.0 No 0.6 part 0.57 2
26 0.95 None [Comparative Example 1] A gypsum aqueous composition was prepared in the same manner as in Example 1 except that the amount of the gypsum dispersant was changed to 1.5 parts in Example 3,
Similar measurements were made. The results obtained are shown in Table 4.

Table 4 Polymer L value Flow value SL value Slag 1.5
Part 1.43 238 0.55 Large 5 [Example 4] In Example 1, the gypsum dispersant was replaced with copolymer (4)
A gypsum aqueous composition was prepared in the same manner as in Example 1, except that the composition was changed to [n/m = 3/7] and the blending amount was varied, and the same measurements were performed. The results obtained are shown in Table 5.

Table 5 Copolymers L value Flow value SL value Slag 0.2
Part 0.12 172 1.0 No 0.4 part 0
．． 25 205 0.87 No 0.6 part 0.37
223 0.88 None [Example 5] In Example 1, the gypsum dispersant was replaced with copolymer (5)
A gypsum aqueous composition was prepared in the same manner as in Example 1, except that the composition was changed to [n/m = 2/8] and the blending amount was varied, and the same measurements were performed. The results obtained are shown in Table 6.

6 Table 6 Copolymer Value Flow value SL value Slag 0.6
Part 0.21 215 0.85 No 0.8 part 0
．． 2.9 220 0.92 None 1.0 part 0.3
8 222 0.92 None [Comparative Example 2] Same as Example 1 except that the gypsum dispersant in Example 1 was changed to sodium polyacrylate [homopolymer, molecular weight approximately 5000] and the blending amount was varied. A gypsum aqueous composition was prepared and similar measurements were performed. The results obtained are shown in Table 7.

Table 7 with blank space below Polymer L value Flow value SL value Water slag 2.0
Part Infinity 110 Unmeasurable Anhydrous 3.0 parts
Same as above 155 0.1 Nakamoto 4.0 parts Same as above 208 0.3 Major zero note: Wood = No condensation even after 24 hours.

[Example 6] A gypsum aqueous composition having the following composition was prepared.

Phosphate gypsum (same as Example 1) 100 parts Ordinary Portland cement 6 parts Aggregate (New Special No. 5 silica sand: manufactured by Ube Electrochemical Co., Ltd.) 70 parts Aggregate (New Special No. 6 silica sand: Ube Electrochemical Paving) 30 parts part borax
0.2 parts gypsum dispersant [copolymer (
1) n/m-3/7] The amount of viscosity modifier shown in Table 8 (Himetrose #30000: Shin-Etsu Chemical ■
) 0.07 parts antifoaming agent (SN Deformer 14HP: manufactured by San Nopco ■) 0.05 parts antifoaming agent (Formaster PC)
, : Manufactured by San Nopco ■) 0.10 parts potassium sulfate
0.1 part water
About 40 parts of the gypsum aqueous composition described in Section 2 was measured in the same manner as in Example 1.

The results obtained are shown in Table 8.

Below margin 9 Table 8 Copolymer L value Flow value SL value Water source 0.8
Part 0.34 175 1.0 No t, o part 0
．． 43 183 0.97 No 1.2 parts 0.52
192 0.92 None 1.4 parts 0.60 1
98 0.85 Unpatented applicant Ube Industries Co., Ltd. - Nippon Shokubai Chemical Co., Ltd. Agent Patent attorney Yasuo Yanagawa 0

Claims (1)

[Claims] ■. A gypsum aqueous composition containing stone, aggregate, a gypsum dispersant, an antifoaming agent, and water, the gypsum dispersant being polyalkylene glycol mono(meth).
It is a (meth)acrylic copolymer containing a structural medium derived from an acrylic acid ester monomer and a structural medium derived from a (meth)acrylic acid monomer, and the blending amount of the gypsum dispersant is as follows. Formula: % Formula %) () () n: Contains the structural unit derived from the (meth)acrylic acid monomer in the gypsum dispersant (1 part) m: Polyalkylene glycol in the gypsum dispersant It is a product that satisfies the content (parts by weight) of structural units derived from mono(meth)acrylic acid ester monomers, and the proportion of gypsum and aggregate is based on 100 parts by weight of gypsum. The amount of aggregate is 10 to 300 parts by weight, the water content M- is 20 to 80% by weight based on the amount of gypsum, and the amount of antifoaming agent is based on the total amount of gypsum and aggregate. 0. O
1. A self-leveling gypsum aqueous composition, characterized in that the aqueous gypsum composition has a flow value of 150 mm or more. 2゜The gypsum dispersant has the general formula: R3 represents hydrogen or an alkyl group having 1 to 5 carbon atoms, p represents an integer of 1 to 100] A structural unit derived from a polyalkylene glycol mono(meth)acrylic acid ester monomer (a) , General formula: %Formula% [However, R4 represents hydrogen or a methyl group, X is hydrogen,
- representing a valent metal, divalent metal, ammonium group or organic amine group] A structural unit (b) derived from a (meth)acrylic acid monomer represented by - 10 to 95% by weight of the structural unit (c) derived from ) and (c) are 100% by weight
The self-leveling gypsum aqueous composition according to claim 1, characterized in that it is a (meth)acrylic acid-based copolymer containing a (meth)acrylic acid copolymer in a ratio of . 3゜The gypsum dispersant contains 50 to 80% by weight of the structural unit (a) derived from the polyalkylene glycol mono(meth)acrylic acid ester monomer, and the gypsum dispersant derived from the (meth)acrylic acid monomer. structural unit (b)
The self-leveling agent according to claim 2, which is a (meth)acrylic acid-based copolymer containing 20 to 50% by weight (however, the total amount of both is 100% by weight). gypsum aqueous composition. 4. The self-leveling gypsum aqueous composition according to claim 1, further comprising cement in an amount of 40% by weight or less based on gypsum. 5. The self-leveling gypsum aqueous composition according to claim 1, further comprising a viscosity modifier, an expansion inhibitor, and a setting modifier.