JPS6011255A - 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 a cement mixture, and prevents the fluidity from decreasing over time, thereby improving 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, it is necessary to increase the unit amount of water. However, increasing the unit amount of water leads to a decrease in strength, so in order to obtain the same strength, it is necessary to increase the unit amount of cement. However, when the unit amount of cement is increased, the curing calorific value increases, which causes the problem that cracks are more likely to occur. Furthermore, after mixing the various materials, cement mixtures are often transported to the pouring site by mixer trucks, etc., but the time required for transportation is subject to change depending on the distance of transportation and the degree of traffic congestion. 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 mixture in the piping has decreased, so the pumping pressure after restarting is There were problems such as having to raise the pipe or partially blocking the pipe.

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

Conventionally, a formalin condensate of sodium naphthalene sulfonate has been known as such an additive, but although this additive can impart fluidity to cement mixtures, it cannot maintain that fluidity for a long period of time. Therefore, the above requirements were not fully met.

Therefore, the present inventors conducted intensive research on cement additives that solved the above problems, and surprisingly found that a specific compound, In other words, the mixture containing the polyoxyethylene compound has a better effect of improving cement particle dispersibility and fluidity than could be achieved with the formalin condensate of naphthalene sulfonic acid metal salt alone, and also prevents the fluidity from decreasing over time. This led to the completion of the present invention.

That is, the present invention is a cement additive comprising a formalin condensate of a naphthalene sulfonic acid metal salt and a polyoxyethylene compound.

In the present invention, the formalin condensate of naphthalene sulfonic acid metal salt is defined by the following general formula (where M is any one of Na, Ca, and n
is an integer from 1 to 20. ), for example, by reacting naphthalene with sulfuric acid and formalin, and then adding the resulting reaction product to sodium hydroxide.

It can be obtained by saponification with calcium hydroxide, potassium hydroxide, etc. In the present invention, M in the above general formula is particularly preferably IJum.

Next, the polyoxyethylene compound is fcH2cH2q
Any compound may be used as long as it has a component of 'k (in the formula, n represents a real number from 1 to 40). Specifically, polyoxyethylene alkylphenyl ether (e.g. ethyloxyethylene nonylphenyl ether).

polyoxyethylene polyaralkyl phenyl ether,
Polyoxyethylene bisphenol A ether, polyoxyethylene alkyl ether (such as polyoxyethylene lauryl ether).

Polyoxyethylene polyoxypropylene block polymer (e.g. polyoxyethylene polyoxypropylene condensate, etc.), polyoxyethylene secondary alcohol ether, polyoxyethylene glycerin fatty acid ester,
Examples include polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene alkyl amine, etc. Among these, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ether, and polyoxyethylene polyoxypropylene block polymer is suitable.

The cement additive of the present invention can be obtained by mixing the above-mentioned formalin condensate of naphthalene sulfonic acid metal salt and a polyoxyethylene compound in a conventional manner. Here, the mixing ratio (weight ratio) of formalin condensate of naphthalene sulfonic acid metal salt and polyoxyethylene compound is usually former/latter = 0.1/99.9 to 90/
range of 10, preferably 0.5/99.5 to 40/60
It is.

The cement additive of the invention thus obtained can be added to cement formulations such as cement pastes of cement and water, mortars of cement, sand and water, concretes of cement, sand, pebbles and water. , its blending amount is 0.05 in terms of solid content based on cement.
~10 parts by weight, preferably 0.1 to 5 parts by weight are suitable. If the blending ratio of the cement additive is less than 0.05% by weight, it is not possible to expect a sufficient effect of improving the dispersibility of cement particles, water reduction effect, and imparting fluidity to the cement mixture. On the other hand, if the weight exceeds 10, the cement will separate to an extreme extent, causing a so-called separation phenomenon, making it impossible to obtain the desired strength. Furthermore, when concrete that has separated is pumped and poured, pipes often become clogged.

Although a cement composition having sufficiently satisfactory properties can be obtained by adding the cement additive of the present invention, other auxiliary ingredients can be added as necessary. However, there is no particular restriction on the timing of adding the cement additive of the present invention, and it can be added at any time from the preparation stage of the cement mixture to just before construction.

By adding the cement additive of the present invention, it is possible to improve the dispersibility of cement particles in a cement mixture, impart fluidity, and extend the duration of the fluidity, thereby improving workability during construction. Improve. Furthermore, this cement additive has a water-reducing effect, and it is possible to obtain mortar and concrete that have sufficient strength without causing cracks or cracks. 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, examples of the present invention will be shown.

Examples 1 to 24 and Comparative Examples 1 to 8 Predetermined amounts of each of cement, sand, and water were placed in a forced stirring type mortar mixer with a capacity of 10 mm, and stirred for 2 minutes. after that,
A mortar was prepared by stirring for an additional 30 seconds with or without the addition of specified additives. About this composition JIS
A flow test with R 5 2 0 4 was conducted. The results and experimental conditions are shown in Table 1.

FIG. 1 shows the results of changes in fluidity over time for the mortar compositions obtained in Example 1 and Comparative Example 2.

-...Ordinary Portland cement (manufactured by Tokuyama Soda Co., Ltd.) I2...Toyoura standard sand -3...Amount added is 0.2% by weight based on cement (solid content equivalent) I4...Naphthalene sulfonate / 40% by weight aqueous solution of polymeric metal condensate (Idemitsu Petrochemical ■, IPC-1000) of sodium acid Aqueous solution 117...Polyoxyethylene polyaralkyl phenyl ether aqueous solution umbrella 8...Polyoxyethylene lauryl ether (C
12 H25 0(C2 H40) 4 H) 40% by weight aqueous solution -9...40% by weight aqueous solution of polyoxyethylene bisphenol A ether H3 I10... Polyoxyethylene polyoxypropylene condensate (H(OC2H4) 13 (C3HgO)an (C
40% by weight aqueous solution of 2H40) + 3H)...Value when 15 minutes have passed after preparing the mortar composition'

[Brief explanation of drawings]

FIG. 1 is a graph showing the change in 7O-value of a mortar composition over time. In the figure, A shows the results of Example 1, and B shows the results of Comparative Example 2. Figure 1 饅逼 (dark c minutes) Procedural amendment (voluntary) August 1, 1980 Commissioner of the Japan Patent Office Kazuo Wakasugi 1. Indication of the case Patent application 114062/1982 2. Name of the invention Cement additive & Make amendments Patent applicant Idemitsu Petrochemical Co., Ltd. 4, agent 1-1-10 Kyobashi, Chuo-ku, Tokyo 104 ) Correct "former/latter" on the bottom line of page 6 of the specification to "latter/former". Procedural amendment (voluntary) June 12, 1980 Commissioner of the Japan Patent Office Kazuo Wakasugi 1. Indication of the case Patent application 1982-114062 2. Name of the invention Cement additive 3. Person making the amendment Relationship to the case Patent application Hitodemitsu Petrochemical Co., Ltd. 4, Agent 104 Address 5 Kyo@1-1-1o, Chuo-ku, Tokyo Subject of amendment 6 "Polyoxyethylene" on page 6, lines 8-9 of the statement of contents of the amendment Examples include alkyl amines, etc., and ``in addition to polyoxyethylene alkyl amines, polyoxyethylene alkyl ethers or alkyl ethers of oxyethylene oxypropylene broth polymers, sodium, ammonia, and alcohol amines, and sulfuric acid. This is corrected to ``reaction products, etc.''. (that's all)

Claims (3)

[Claims] (1) A cement additive consisting of a formalin condensate of naphthalene sulfonic acid metal salt and a polyoxyethylene compound. (2) The cement additive according to claim 1, which is a formalin condensate of sodium naphthalene sulfonate. (3) The polyoxyethylene compound is selected from polyoxyethylene polyoxypropylene condensate, polyoxyethylene polyaralkyl phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene bisphenol A ether, and polyoxyethylene polyoxypropylene condensate. A cement additive according to claim 1, which is one or more of the following.