JPS6183662A - Cement additive - 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 cement additives, in particular cement formulations (cement paste, mortar and concrete).
The present invention relates to a cement additive that improves the dispersibility of cement particles, improves the fluidity of cement mixtures, prevents the fluidity from decreasing over time, and improves workability.

In cement mixtures such as cement paste, mortar, and concrete, the cohesive force of cement particles is strong, so that a cement mixture with good workability cannot be obtained with the unit amount of water required for hardening the cement. Therefore, in order to improve the workability of cement mixtures, the amount of water at the 11th place was reduced to 1
It is necessary to add 19. However, increasing the unit mercury causes a decrease in strength, so in order to obtain the same strength, it is necessary to increase the unit cement amount. However, when the cement amount per unit was increased by 11, the curing heat generation increased, which caused the problem that cracks were more likely to occur. In addition, after mixing the various materials, cement mixtures are often transported to the pouring site using mixer trucks, etc., but the time required for transportation varies depending on the transportation distance and the degree of traffic congestion. Cheap. For this reason, the fluidity of the cement mixture varies at the pouring site, making it difficult to obtain consistent workability. Furthermore, when pumping a cement mixture using a pump, if the pumping is interrupted for some reason and then restarted, the fluidity of the cement I/mixture in the piping is reduced, so after restarting, There were problems such as the need to increase the pumping pressure or partial blockage of piping.

As mentioned above, the simplest means to improve the fluidity of a concrete mixture is to increase the amount of water in the mixture, but increasing the amount of mercury causes cracks and flaking after construction. Therefore, there is a need for an additive that has a water-reducing effect, improves the viscosity of cement particles, provides suitable fluidity, and is capable of maintaining this fluidity.

Conventionally, salts of formalin condensate of sodium naphthalene sulfonate, salts of formalin 116 compound of alkylnaphthalene sulfonic acid, etc. have been known as such talking power agents, and the addition of these agents has increased the degree of increase in cement composition. Although it can provide a good amount of liquidity, it is still not sufficient.
Moreover, it was not possible to maintain the flow+J+ property for a long period of time.

Therefore, the present inventors conducted intensive research to develop a cement additive that provides sufficient fluidity to concrete mixtures and prevents the fluidity from decreasing over time. It was discovered that the cement additive described above can achieve the above object, and based on this knowledge, the present invention was completed.

That is, the present invention is a cement additive comprising two or more types of fluidizing agents, one of which is a saponified product of a styrene-maleic acid copolymer.

In the present invention, the saponified product of styrene-maleic acid copolymer is represented by the following general formula.

(In the formula,
It is an integer of 10. ) The saponified product of styrene-maleic acid copolymer is styrene-
Sodium hydroxide maleic acid copolymer.

It can be obtained by saponifying potassium hydroxide, calcium hydroxide, )F:, ammonium ffZ, and the like. Here, the snalene-maleic acid copolymer may be either a random copolymer or a flock copolymer (a combination), and the number average molecular weight is 1000 to 90.
00, preferably 1500 to 3000.

The cement additive of the present invention consists of a saponified styrene-maleic acid copolymer and one or more other fluidizing agents. There are no particular limitations on other fluidizing agents, and known ones can be used, such as salts of formalin condensates of naphthalenesulfonic acids, salts of formalin condensates of alkylnaphthalenesulfonic acids, naphthalenesulfone iU, and alkylnaphthalenesulfonic acids. Salt of formalin condensate, naphthalene sulfonic acid and lignin, formalin 11 compound of sulfonic acid Nano 4-'J
Kuninsulfonic acid salt, sulfonated product of formalin condensate of melamine, saponified product of sulfonated styrene-maleic acid copolymer, salt of formalin condensate of sulfonated creosote oil, city quality Wakazoku dehydrogenated oil Various fluidizing agents may be mentioned, such as salts of formalin condensates of sulfonated products. In addition, salts of these substances include 1-lium salt and potassium salt.

Calcium salts, ammonium salts, etc. are preferred.

The present invention is a cement additive comprising one or more of the above-mentioned fluidizing agents. There is no particular restriction on the blending ratio of each of these components, and they can be blended in various ratios. Usually, the total amount of other fluidizing agents is 5 to 900 parts by weight, preferably 25 to 400 parts by weight, based on 100 parts by weight of the saponified styrene-maleic acid copolymer.

The cement additive of the present invention is a cement paste consisting of cement and water; a mortar consisting of cement, sand and water;
It is added to cement mixtures such as concrete consisting of cement, sand, pebbles, and water, but it is also possible to mix and knead each of the above-mentioned components and add it to these, or to add a predetermined amount of each component to the cement mixture. It may be added to.

There is no particular restriction on the amount of the cement additive of the present invention added to the cement mixture, but it is 0.000% in terms of solid content relative to cement. O1-1.0%, preferably 0.05-0.5
Weight % is appropriate.

In addition, in addition to the cement additive of the present invention, other known cement additives, ie, water reducing agents, may be used as necessary.

Retarders, curing accelerators, air-entraining agents, air-entraining water-reducing agents, and other auxiliary components may be added as appropriate.

By adding the cement additives of the present invention, it is possible to improve the dispersibility of the cement particles of the cement formulation and to impart suitable flowability, as well as to extend the duration of the flowability. Therefore, the workability of pouring the cement mixture is significantly improved. Furthermore, this cement additive has a water-reducing effect and does not cause cracks, etc.
Mortar and concrete with sufficient strength can be obtained. Therefore, the cement additive of the present invention is extremely useful in fields such as civil engineering and architecture, as well as in fields dealing with secondary concrete products.

Next, the present invention will be explained in detail with reference to examples.

Production Example 1 (Production of saponified product of styrene-maleic acid copolymer) In a 100-mn glass reactor, 1.1% of sulfur and lithium hydroxide were placed.
77 kg and 1.2 kg of water were charged and stirred to prepare an alkaline aqueous solution. Furthermore, a styrene-maleic acid copolymer (manufactured by ARCO Chemica 1, USA, rSMA-1000J, number average molecular weight 1600, styrene:maleic anhydride M=1:1 (mole ratio), acid value 48) was added to this aqueous solution.
0mg-KOH/g) 6.4.5kg was charged and stirred at a reaction temperature of 90°C. After 2 hours of reaction, the aqueous solution became transparent and the reaction was terminated.

The reaction product was a pale yellow viscous solution with a pH of 7.22 and a styrene-maleic acid saponide concentration of 37%. This is designated as the (Z) component.

Production Example 2 (Preparation of sodium salt of formalin condensate of naphthalene sulfonic acid) Add 600 g of 98% sulfur M to 500 g of naphthalene,
Sulfonation was achieved by treatment at 160"C for 1.5 hours.

Next, 310 g of formalin with a concentration of 37% at 100°C
was added dropwise and premixing was carried out for 5 hours.

The resulting condensate was subjected to liming sodation in a conventional manner to obtain a sodium salt of a formalin condensate of naphthalenesulfonic acid. This is called component (A).

Production Example 3 (Production of Natriuno, salt of a polymarin condensate of methylnaphthalene sulfonic acid) 600 g of 98% sulfuric acid was added to 500 g of β-methylnaphthalene, and the mixture was treated at 160° C. for 1.5 hours to perform sulfonation. Next, 310 g of formalin with a concentration of 37% was added dropwise at 100'C, and the mixture was incubated for 5 hours.

The obtained condensate was subjected to liming sodation in a conventional manner to obtain a sodium salt of a formalin condensate of methylnaphthalenesulfonic acid. This is called component (B).

Production Example 4 (Preparation of sodium salt of formalin condensate of naphthalene sulfonic acid and methylnaphthalene sulfonic acid) 600 g of 98% sulfuric acid was added to 100 g of β-methylnaphthalene and 400 g of naphthalene, and treated at 160°C for 1.5 hours. Sulfonated. Then, at 100°C and at a concentration of 37
% formalin was added dropwise, and premixing was carried out for 5 hours. At this time, when the viscosity increased -■-, a small amount of water was added to lower the viscosity and condensation was carried out.

The obtained cocondensate was subjected to a conventional liming sodation method to obtain a sodium salt of a formalin condensate of naphthalenesulfonic acid and methylnaphthalenesulfonic acid. This is called component (C).

Production Example 5 (Production of sodium salt of formalin condensate of naphthalenesulfonic acid and ligninsulfonic acid) Take 100 g of naphthalenesulfone H and geninsulfone d3
Add 00 g of 98% sulfuric acid to a concentration of 37 at 100"C.
% formalin was added dropwise, and condensation was carried out for 5 hours. At this time, when the viscosity increased, a small amount of water was added to lower the viscosity and condensation was performed.

The obtained cocondensate was subjected to liming sodation in a conventional manner to obtain a sodium salt of a formalin condensate of naphthalenesulfonic acid and ligninsulfonic acid. This (D)
It is called an ingredient.

Production Example 6 (Formation of sodium salt of ligninsulfonic acid) After oxidizing sulfite pulp waste liquid with hydrogen peroxide under alkaline conditions, it was subjected to ultrafiltration (molecular weight cut off: 1000) and purified to obtain ligninsulfone 1. Ta.

Lignosulfonic acid sodium salt was obtained from the obtained geninsulfonic acid by a conventional liming sodation method. This is called component (E).

Production Example 7 (Production of sulfonated product of formalin condensate of melamine) In a glass reactor, 76 g of a 37% aqueous formalin solution adjusted to pH 8 with sodium carbonate and 29 g of melamine were added.
g and heated to 70°C. After 5 minutes, the melamine was completely dissolved and the reaction solution became transparent. The reaction mixture was immediately cooled, and 48 g of water and 25 g of sodium sulfite were added while maintaining the temperature of the reaction liquid at 45°C. After that, the temperature was raised to 80℃ and 200℃
A time reaction was carried out to obtain a sulfonated product of formalin condensate of melamine. This is called component (F).

Production Example 8 (Production of saponified product of sulfonated styrene-maleic acid copolymer) 104 g of styrene and 98 g of maleic anhydride were copolymerized at 175°C in the presence of benzoyl peroxide as a catalyst to produce a styrene-maleic copolymer. I got it. Add 200g of 98% sulfuric acid to 100g of this copolymer and heat to 100°C.
The mixture was reacted for 2 hours to effect sulfonation. Then add 50 ml of water
After dilution by adding 0 g, liming sodation was performed at 60°C to obtain sodium salt. This is called component (G).

Production Example 9 (Production of sodium salt of formalin condensate of sulfonated creosote oil) Add 600 g of 98% sulfuric acid to 500 g of creosote oil,
Sulfonation was carried out at 150°C. Then, concentration 37%
310 g of formalin was added dropwise, and condensation was carried out at 100'C for 5 hours.

The obtained cocondensate was subjected to liming sodation in a conventional manner to obtain a sodium salt of a formalin condensate of a sulfonated creosote oil. This is called component (H).

Mold Preparation Example 10 (Production of sodium salt of formalin condensate of sulfonated heavy aromatic hydrocarbon oil) 600 g of 98% sulfuric acid was added to 500 g of heavy aromatic hydrocarbon oil, and sulfonation was carried out at 150°C for 2 ili. I did it.

Next, 310 g of formalin with a concentration of 37% was added dropwise, and 1
Incubation was carried out at 00°C for 5 hours.

The obtained cocondensate was subjected to liming sodation in a conventional manner to obtain a sodium salt of a formalin condensate of a sulfonated heavy aromatic hydrocarbon oil.

This is called component (I).

Examples 1 to 8 and Comparative Examples 1 to 8 Cement,
Predetermined amounts of sand, pebbles, and water were added and stirred for 2 minutes.

After that, add the prescribed force shown in Table 1,
The mixture was further stirred for 30 seconds to prepare a concrete composition. In addition, components (A) to (1) are usually used as a 20 to 40% by weight aqueous solution.

The concrete composition thus obtained was evaluated by measuring air, slump value, and compressive strength. The results are shown in Table 1.

*1... Hiroshi Tokuyama "No! (1 mounting, Tetsutsu Portland cement *2... Made in Shikoku Omishima Nagahama, surface dry specific gravity 252, coarse grain ratio 2.34 *3... Crushed stone from Suohanaoka, surface Dry specific gravity 2.70, *5
・ ・ ・ J I5A-1121H Section 1 *6... Based on JISA-1101 *7... J [Procedure amendment S based on 5A-1108 (voluntary) October 23, 1980

Claims (2)

[Claims] (1) A cement additive comprising two or more types of fluidizing agents, one of which is a saponified product of a styrene-maleic acid copolymer. (2) The fluidizing agent other than the saponified product of styrene-maleic acid copolymer is a salt of a formalin condensate of naphthalenesulfonic acid, a salt of a formalin condensate of alkylnaphthalenesulfonic acid, a salt of a formalin condensate of alkylnaphthalenesulfonic acid, a salt of naphthalenesulfonic acid, and alkylnaphthalenesulfonic acid. Salts of formalin condensates, salts of formalin condensates of naphthalenesulfonic acid and ligninsulfonic acid, salts of ligninsulfonic acids, sulfonated products of formalin condensates of melamine, saponified products of sulfonated styrene-maleic acid copolymers, creosote The cement additive according to claim 1, which is at least one selected from a salt of a formalin condensate of a sulfonated oil and a salt of a formalin condensate of a sulfonated heavy aromatic hydrocarbon oil.