JPH03290345A - Cement dispersant composition - Google Patents

Abstract

PURPOSE:To improve dispersing ability of cement slurry, etc., by further hydrolyzing a sulfonated substance of a copolymer comprising a styrene monomer, etc., to give e carboxyl group-containing water soluble copolymer and forming a dispersant composed of this copolymer and another compound. CONSTITUTION:This dispersant comprises a carboxyl group-containing water-soluble copolymer (A) prepared by hydrolyzing a sulfonated substance of a specific copolymer (c) and a specific compound (B). The specific copolymer (c) consists of styrene units (a) and (meth)acrylic acid units (b). The specific compound (B) is selected from a condensate of naphthalenesulfonate and formalin, lignin sulfonate, sulfonated melamine resin and sulfonate of creosote oil.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to cement dispersant compositions.

[Prior Art] As cement dispersants, formalin condensates of naphthalene sulfonates, lignin sulfonates, sulfonated melamine resins, and the like are known.

[Problems to be Solved by the Invention] These have excellent cement dispersion ability and exhibit excellent fluidity immediately after being kneaded with water.

However, after kneading, the problem is that the fluidity rapidly decreases over time.

[Means for Solving the Problems] The present inventors have arrived at the present invention as a result of studying a dispersant composition suitable for cement that does not have such problems.

That is, the present invention provides a copolymer (c) consisting of a styrene unit (a) and a (meth)acrylate unit (b).
This is a cement dispersant composition comprising a carboxyl group-containing water-soluble copolymer (A) obtained by further hydrolyzing a sulfonated product of the above formula and another dispersant.

Preferably, a formalin condensate of the water-soluble copolymer (A) and naphthalene sulfonate, a lignin sulfonate, a sulfonated melamine resin, a creosote oil sulfonate, a polystyrene sulfonate, and an α-olefin sulfone. A cement dispersant composition comprising a compound (B) selected from the group consisting of acid salts.

The present invention will be explained in more detail below.

The copolymer (c) used in the present invention will be explained.

The copolymer (c) is composed of styrene units (a) and (meth)acrylate units (b).

(a) Monomeric styrene constituting the styrene unit, α-
such as methylstyrene.

(b) Monomers constituting the (meth)acrylate unit: methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate ,(
2-ethylhexyl meth)acrylate, octyl (meth)acrylate, isodecyl (meth)acrylate,
(meth)acrylic acid alkyl esters such as lauryl (meth)acrylate, tridecyl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, preferably methyl acrylate, and methyl methacrylate. be.

Moreover, the copolymer (c) in the present invention can contain other monomer units if necessary.

For example, water-soluble vinyl monomers include unsaturated (di)carboxylic acids or their acid anhydrides [(meth)acrylic acid, (
anhydride) maleic acid, fumaric acid, itaconic acid, etc., amide group-containing vinyl monomers [(meth)acrylamide, N-
Methyl (meth)acrylamide, N, N, -dimethylacrylamide, etc.], hydroxyl bases are substituted with vinyl monomers [hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, triethyleneglyfur (meth)acrylate, (meth)acrylate, etc.], ) Allyl alcohol, N-vinylpyrrolidone, etc. Examples of poorly water-soluble vinyl monomers include fatty acid vinyl monomers (vinyl acetate, vinyl propionate, etc.) and nitrile group-containing vinyl monomers ((meth)acrylonitrile, etc.). Preferred are maleic anhydride, maleic acid, methacrylic acid, and acrylic acid, and more preferred is maleic anhydride.

The content of styrene monomer units (a) and (meth)acrylic acid ester monomer units (b) is usually 3G-90 mol%
and 10 to 70 mol%, preferably 40 to 70 mol%
and 3O-80 mol%.

The average molecular weight of the copolymer (c) is usually 1 (100 to 1
0,000,000, preferably 2,000 to 100,000.

The sulfonation of the copolymer (c) is carried out using a conventional sulfonating agent in a solvent by a known method. That is, as the sulfonating agent, sulfuric anhydride (hereinafter referred to as Sob), chlorosulfonic acid, etc. are used. In particular, S.O.
s is 50m of liquid, inert gas such as nitrogen or dry air, and carbon number 1 such as 1,2-dichloroethane or ethyl chloride.
-2 diluted with an aliphatic halogenated hydrocarbon, etc. can be used.

The amount of the sulfonating agent used is usually 0.5 to 2 moles, preferably 0.8 to 1.5 moles, per mole of styrene units in the copolymer (c). If the molar amount used is small, the degree of sulfonation will be insufficient and insoluble matter will increase, while if the molar amount used is large, by-products such as sulfate will increase.

As the solvent, an aliphatic halogenated hydrocarbon having 1 to 2 carbon atoms is usually used. Specific examples of such halogenated hydrocarbons include 1,2-dichloroethane, methylene dichloride, ethyl chloride, carbon tetrachloride, 1,1-dichloroethane, 1,1.2.2-tetrachloroethane, chloroform, and ethylene. It is inert to sulfonating agents such as difuromide. The amount of solvent used depends on the molecular weight of the copolymer (c), but is usually
The amount is 1 to 30 parts by weight, preferably 2 to 20 parts by weight.

The sulfonation temperature is usually 0 to 80°C.

After sulfonation, it is usually neutralized with hydroxides, carbonates, etc. of alkali metals, alkaline earth metals, etc., and the solvent is separated by filtration, distillation, etc., and the sulfonated product is produced in the form of powder or aqueous solution. Get salt.

The sulfonated product is further heated in acidic or alkaline water at usually BG to 180°C, preferably 100 to 150°C to decompose the ester in the sulfonated product to obtain a water-soluble polymer (A) containing carboxyl groups. The constituent components of this water-soluble polymer (A) include (meth)acrylic acid units, usually 8 to 8 mol%, preferably 30 to 60 mol%, (
Meth)acrylic acid ester units are usually 0 to 40 mol%
, preferably 1 to 20 mol%, sulfonated styrene units typically 1 to 30 mol%, preferably 40 to 70 mol%, styrene units usually 0 to 45 mol%, preferably 1 to 20 mol%. .

Compound (B) according to the present invention is a formalin condensate of naphthalene sulfonate, lignin sulfonate, sulfonated melamine resin, creosote oil sulfonate, polystyrene sulfonate, and α-olefin sulfonate. Choose at least one of them.

Here, the formalin condensate of naphthalene sulfonic acid is
Usually, naphthalene is reacted with sulfuric acid and formalin,
Further, it can be obtained by neutralization treatment with sodium hydroxide, calcium hydroxide, magnesium hydroxide, ammonia water, etc. Lignosulfonate is a product obtained by reacting lignin and lignin derivatives obtained from wood etc. with sulfuric acid, fuming sulfuric acid, etc. The sulfonated melamine resin can be obtained by reacting melamine, formalin, and sulfite using a conventional method. Additionally, conventional cement dispersants such as creosote oil sulfonate, polystyrene sulfonate, and alpha-olefin sulfonate are used. Preferred are formalin condensates of ligninsulfonates and naphthalenesulfonates.

In the dispersion composition of the present invention, component (A) usually has a content of 5 to 70%
Component (B) is usually 3G-95% by weight, preferably 40-90% by weight. When component (A) is less than 5% by weight, the effect of improving slump loss is small, and when it is more than 70% by weight, it is economically disadvantageous.

Other components can also be added to the dispersion composition of the present invention, if necessary. Other ingredients include air entraining agents [alkylbenzene sulfonates, sulfuric ester salts of higher fatty acid alkylene oxide adducts, buinzol, etc.], carboxylic acid cement dispersants [polyacrylates, isobutylene], etc.
hardening accelerators [calcium chloride, sodium carbonate, potassium carbonate, sodium thiosulfate, alkanolamines, saturated or unsaturated carboxylic acids, etc.], hardening retarders [gluconic acid, citric acid, etc.] , tartaric acid, polyphosphoric acid, etc., sizing agents [polyvinyl alcohol, starch, carboxymethylcellulose, hydroxymethylcellulose, sodium alginate, etc.], and rust preventives [sodium nitrite, calcium nitrite, etc.].

Examples of cements that can be used with the cement dispersant composition of the present invention include ordinary Portland cement, special Portland cement (for example, early strength Portland cement, moderate heat Portland cement, etc.), alumina cement, fly ash cement, blast furnace cement, etc. . Among these, preferred is ordinary Portland cement.

A method for dispersing cement using the dispersion composition of the present invention will be explained.

The amount of the dispersant composition of the present invention added can vary depending on the use of the cement and the required performance, but it is usually 0.05 to 5% by weight, preferably 0.05 to 5% by weight, based on the cement. It is 1 to 2% by weight.

The means for adding the dispersant composition of the present invention can be used in the same manner as in the case of conventional cement admixtures.

For example, an appropriate amount of the dispersant composition may be mixed in advance with the kneading water, or it may be added to concrete slurry or the like that has been thoroughly kneaded.

Furthermore, a method may be employed in which a part of the present invention is added at the time of crosstalk, and then the remaining dispersant composition of the present invention is added in one or more portions.

The method for constructing mortar and concrete containing the product of the present invention may be the same as conventional methods, and various methods may be used such as troweling, spraying, filling into formwork, and injection using a caulking gun. The curing method may be air dry curing, humid air curing, water curing, or heating accelerated curing.

[Examples] Hereinafter, the present invention will be further explained with reference to Examples, but the present invention is not limited thereto. Parts and percentages in the examples are by weight.

Production Example 1 Styrene-methyl acrylate copolymer (molar ratio 80/4
0, average molecular weight 25,000) was dissolved in ethylene dichloride and sulfonated with anhydrous sulfuric acid according to a conventional method. Add 30% aqueous sodium hydroxide solution,
The pH was adjusted to 8. After heating and distilling the solvent, 30
% sodium hydroxide aqueous solution, and the temperature was 110°C.
The mixture was further heated until methanol no longer distilled out. The amount of methanol distilled out was 12 parts.

After cooling, water was added and the evaporation residue was 33%, 3 acrylic acid units.
An aqueous copolymer solution (A-1) containing 8 mol% of methyl acrylate units, 56 mol% of styrene sulfonic acid units, and 4 mol% of styrene units was obtained.

Production Example 2 Styrene-methyl methacrylate copolymer (molar ratio 50
/5G, average molecular weight 23.000) was dissolved in ethylene dichloride and sulfonated with anhydrous sulfuric acid according to a conventional method. Furthermore, it was hydrolyzed with 65 parts of a 30% aqueous sodium hydroxide solution in the same manner as in Production Example 1, and the evaporation residue was 33%, 48 mol% of methacrylic acid units, 2 mol% of methyl methacrylate units, and 48 styrene sulfonic acid units.
copolymer aqueous solution containing 2 mol% of styrene units (A-
2) was obtained.

Examples 1 to 3, Comparative Examples 1 to 2 Copolymer aqueous solutions of Production Examples 1 and 2 (A-1) (A-2
) A dispersant composition of the present invention and a comparative product were obtained using a formalin condensate of sodium geninsulfonate and sodium naphthalenesulfonate, and according to JAS A 1101,
A slump test was conducted. Parts by weight of the dispersant composition (
Table 1 shows the solid content (solid content), materials used, and blending ratios (Table 1).

Example 1 Aqueous copolymer solution (A-1) 20 parts Sodium lignin sulfonate (Vanirex N1 manufactured by Dezumi Kokusaku Pulp) 80 parts Example 2 Aqueous copolymer solution (A-1) 40 parts Sodium lignin sulfonate ( Vanilex N1 (manufactured by Dezumi Kokusaku Pulp) 60 parts Example 3° Copolymer aqueous solution (A-2) 50 parts Formalin condensate (Sanyo Shibelon, manufactured by Sanyo Kasei) 50 parts Comparative example! .

Sodium lignin sulfonate (Vanirex N1 manufactured by Dezumi Kokusaku Valve) Comparative example 2゜ sodium naphthalene sulfonate Formalin condensate (Sanyo Beron, manufactured by Sanyo Chemical) Materials used Cement: Ordinary Portland cement Fine aggregate: Yoshino river sand Coarse aggregate: Crushed stone from Ako water AE agent: Hozolith No. 303A (Made by Nisso Masters) However, the AE agent was used as necessary.

Table 1 of sodium naphthalene sulfonate Table 1 Preparation ratio table 2 Table 2 shows the amount of the dispersion composition of the present invention added and the change over time in the slump value of the concrete slurry. Note that the amount of air immediately after crosstalk was adjusted within the range of 3.7 to 4.4% using an AE agent in both Examples and Comparative Examples.

1) Weight% of cement (converted to evaporation residue) 2)
Target slump value: 19 cm 3) Loss ratio: The higher the percentage of the slump value 90 minutes after mixing to the slump value immediately after mixing, the better the slump loss is. This material has the effect of having excellent dispersion ability and low slump loss when added to cement slurry in a low amount. In particular, it is useful for ready-mixed concrete used in the framework of buildings.

Claims (1)

[Claims] 1. A carboxyl group-containing water-soluble copolymer obtained by further hydrolyzing a sulfonated copolymer (c) consisting of a styrene unit (a) and a (meth)acrylic acid ester unit (b) A cement dispersant composition comprising (A) and other dispersants. 2. The other dispersant is from the group consisting of formalin condensate of naphthalene sulfonate, lignin sulfonate, sulfonated melamine resin, creosote oil sulfonate, polystyrene sulfonate, and α-olefin sulfonate. The dispersant composition according to claim 1, comprising the selected compound (B).