JPH03199148A - Cement dispersion composition - Google Patents

Abstract

PURPOSE:To obtain the composition which is high in initial fluidity and small in lowering with the lapse of time in fluidity by blending the respectively specified formalin condensate salt, the copolymer salt of olefin and unsaturated dicarboxylic acid anhydride and inorganic salt. CONSTITUTION:Cement dispersion composition is obtained which incorporates (A) at least one kind selected from among alkali metallic salt, alkaline earth metallic salt, ammonium salt and amine salt of a compd. which is obtained by sulfonating aromatic hydrocarbon oil contg. naphthalene and/or alkyl naphthalene as a main component and then condensing the sulfonated substance with formalin, (B) at least one kind selected from among alkali metallic salt, alkaline earth metallic salt, ammonium salt and amine salt of the copolymer of 2-10C olefin and unsaturated dicarboxylic acid anhydride having an ethylenic double bond and (C) at least one kind selected from among nitrite, thiosulfate, thiocyanate and sulfate.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a cement dispersion composition, and more specifically, to fluidize cement paste, mortar, or concrete that is a cement mixture, and to improve the fluidity over time. This invention relates to a cement dispersion composition that exhibits small deterioration.

<Prior art> In order to improve the workability of cement mixtures such as cement paste, mortar, or concrete, it is necessary that the initial fluidity of the cement mixture is high and that the change in fluidity over time is small. .

It is known that fluidity decreases over time mainly due to hydration reaction between cement and water and physical aggregation between the mixture.

Cement mixtures such as cement paste, mortar, and concrete undergo physical and
Chemical aggregation progresses, fluidity decreases, and workability and construction efficiency decrease over time. This phenomenon is generally called mortar flow reduction or concrete slump loss, and limits the pot life of the concrete.

In the case of fresh concrete, concrete slump loss causes problems such as limited transportation time, waiting time at the pouring site, quality deterioration due to temporary interruption of pump pressure, and poor workability.

Furthermore, in the case of secondary concrete products, slump loss of concrete causes limitations in molding time and poor centrifugal compaction.

Therefore, cement paste, which is a cement formulation,
Slump loss, the decline in fluidity of mortar or concrete over time, is an important problem to be solved.

<Problems to be Solved by the Invention> For this reason, several methods have been conventionally considered as measures to prevent slump loss in concrete.

(1) Japanese Patent Publication No. 51-15856 discloses concrete admixtures selected from conventionally known water-soluble salts of sulfonated aromatic compounds or water-soluble salts of formalin condensates of sulfonated aromatic compounds. A method has been disclosed in which fluidity is maintained for a long period of time by repeatedly adding an agent. Although this method is effective to some extent, it is time-consuming to add, not only does it have poor workability, but also is not economical. It is also disadvantageous.

(2) The method of adding a setting retarder such as oxycarboxylic acid can prevent slump loss to some extent, but it causes a delay in curing time and a decrease in initial strength.

(3) JP-A-54-139929 discloses that a concrete admixture such as naphthalene sulfonic acid formalin condensate is granulated and added to concrete, etc., and the granular admixture is gradually dissolved. A method for preventing slump loss is shown.

Although this method can prevent slump loss to some extent, it is difficult to control the dissolution rate of the admixture;
If some parts remain in the concrete, the strength and durability of the concrete will decrease.

(4) JP-A-60-16850 discloses a water-soluble salt of a copolymer of C2-C4 olefin and ethylenically unsaturated dicarboxylic acid, and JP-A-63-10107 discloses styrene and maleic anhydride. An additive made of a saponified copolymer of Furthermore, if the amount added to a cement mixture is increased in order to maintain fluidity for a long time, the curing time will be significantly delayed and the initial strength will be reduced.

As described above, none of the conventional methods for preventing slump loss is practically sufficient.

The present invention solves the above-mentioned problems of the prior art, and provides a new cement dispersion composition that has high initial fluidity of the cement mixture, and has a small decline in fluidity over time without slowing hardening or decreasing initial strength. is intended to provide.

Means for Solving the Problems> As a result of intensive studies, the present inventors have found that the above problems can be solved.
It has been found that by using a specific curing accelerator, a cement dispersion composition can be obtained that has high initial fluidity of the cement formulation, and has a small decline in fluidity over time without slowing curing or decreasing initial strength. .

That is, according to the present invention, in order to achieve the above object,
A cement dispersion composition containing the following components (A), (B) and (C) is provided.

(A) Alkali metal salts, alkaline earth metal salts, ammonium salts and ayone of compounds obtained by sulfonating aromatic hydrocarbon oil containing naphthalene and/or alkylnaphthalene as main components and then condensing with formalin. At least one selected from the group consisting of salts (B) charcoal i number 2
an alkali metal salt of a copolymer of ~10 olefins and an unsaturated dicarboxylic acid anhydride having an ethylenic double bond,
at least one (C) nitrite selected from the group consisting of alkaline earth metal salts, ammonium salts, and amine salts;
One or more compounds selected from the group consisting of thiosulfates, thiocyanates, and sulfates.The component (B) is 10 parts by weight or more based on 100 parts by weight of the component (A). is preferable.

The amount of component (C) is preferably 50 to 500 parts by weight based on 100 parts by weight of component (B).

The olefin having 2 to 10 carbon atoms is preferably a light oil containing indene as a main component.

The present invention will be explained in more detail below.

As the aromatic hydrocarbon oil containing naphthalene and/or alkylnaphthalene as a main component, aromatic hydrocarbons such as naphthalene and methylnaphthalene may be used alone or in combination.

Furthermore, naphthalene oil fractions and methylnaphthalene oil fractions obtained in the coal tar distillation process can also be used. The oil obtained by distilling these coal tars may be used as is, or may be used after various pretreatments.

The compounds obtained by sulfonating these aromatic hydrocarbon-containing oils by a conventional method and then condensing them with formalin are used as alkali metal salts, alkaline earth metal salts, ammonium salts and amine salts.

Specific examples of olefins having 2 to 10 carbon atoms include ethylene, propylene, 1-butene, 2-butene, isobutyne, 1-pentene, 2-pentene, 2-methyl-1-butene, cyclopentene, 1-hexene, 2 -methyl-1-
Pentene, 3-methyl-1-pentene, 4-methyl-1
-pentene, 2-ethyl-1-butene, diisobutylene, cyclohexene, styrene, alpha-methylstyrene, indene, methylindene, dicyclopentadiene and mixtures thereof.

Light oil containing indene as a main component has a boiling point range of about 150 to 2
Examples include heavy gas oil at 50°C (hereinafter referred to as coal tar naphtha fraction, commonly known as CN oil), a fraction obtained by removing benzene, toluene, xylene, etc. from coke oven gas light oil (commonly known as 09 oil), and a petroleum-based 09+ fraction. It is desirable to contain indene in an amount of 25% by weight or more, but if this content is small, it can be increased to 25% by weight or more by a simple distillation operation.

These light oils may include coumaron, dicyclopentadiene, styrene, methylindene, and the like. Further, it may be used after various pre-treatments.

Examples of the unsaturated dicarboxylic anhydride include those having an olefinic double bond, such as maleic anhydride and itaconic anhydride, with maleic anhydride being preferred.

In the copolymer of the olefin and the unsaturated dicarboxylic anhydride, the molar ratio of the olefin having 2 to 10 carbon atoms to the unsaturated dicarboxylic anhydride is preferably in the range of 2/1 to 2/3. This is because when the molar ratio exceeds 2/1 and the amount of unsaturated dicarboxylic acid anhydride is small, no significant effect is obtained in reducing changes in fluidity over time, and the molar ratio is 2/3.
This is because even if an excess amount of unsaturated dicarboxylic acid anhydride is used, no special effect can be obtained and it is not economical.

The above-mentioned copolymer is not used as it is, but is used as a salt of the copolymer in order to quickly exhibit a dispersion effect and to make it water-soluble. That is, they are used as alkali metal, alkaline earth metal, ammonium salts and amine salts.

The acid anhydride may be completely neutralized by these salts, but
It does not matter if it remains partially as an acid anhydride.

Any method may be used for producing the above copolymer, but
For example, an olefin having 2 to 10 carbon atoms and maleic anhydride are reacted under radical polymerization conditions in the presence or absence of a radical initiator to form a copolymer, which is then neutralized using sodium hydroxide to form a copolymer. The sodium salt is preferred.

Specific examples of compounds consisting of nitrite, thiosulfate, thiocyanate and sulfate include sodium nitrite, potassium nitrite, calcium nitrite, sodium thiosulfate, potassium thiosulfate, calcium thiosulfate, sodium thiocyanate, thiocyanate. Examples include potassium acid, calcium thiocyanate, sodium sulfate, potassium sulfate, calcium sulfate, and the like. Even when used alone, these
Further, two or more types may be mixed and used.

Further, as a mixture of these, desulfurization waste liquid obtained by treating carbonized coal gas by the Fumax-Rodax method can be used. The desulfurization waste liquid is a mixture of ammonium thiocyanate, ammonium thiosulfate and ammonium sulfate.

These are known as hardening accelerators for cement formulations, and various hardening accelerators other than those mentioned above are also known. However, if a hardening accelerator other than the one according to the present invention is used, either no significant effect on reducing the change in fluidity of the cement mixture over time is obtained, or no hardening accelerating effect is observed.

Sulfonation of aromatic hydrocarbon oils - Formalin condensate salts (
The blending ratio of component (A) and the salt of the copolymer (component (B)) is preferably 10 parts by weight or more of component B) per 100 parts by weight of component (A). If the amount of component (B) is less than 10 parts by weight, no significant effect on reducing changes in fluidity over time will be obtained.

Copolymer salt (component (B)), nitrite, thiosulfate,
One or 2f of compounds selected from the group consisting of thiocyanates and sulfates! The blending ratio of the above mixture (component (C)) is preferably 50 to 500 parts by weight of component C) per 100 parts by weight of component (B). (C) component is 5
If the amount is less than 0 parts by weight, the curing time will be delayed and the initial strength will be lowered, and if it is more than 500 parts by weight, no significant effect will be obtained in reducing changes in fluidity over time.

The cement dispersion composition of the present invention is 0.01% relative to cement.
It is used in the range of ~1.0% by weight, but 0.1~0.5
% by weight is particularly preferred.

If the amount added is less than 0.1% by weight, the initial fluidity will be low;
Even if it exceeds 5% by weight, there is almost no change in performance and only the economical efficiency deteriorates.

The cement dispersion composition of the present invention may be added to kneading water of a cement mixture, or may be added to a thoroughly kneaded cement mixture.

<Examples> The present invention will be specifically described below based on Examples, but the present invention is not limited thereto.

(Example 1) As the (A) component, a commercially available sodium salt of naphthalene sulfonic acid-formalin condensate was used, and as the (B) component, it contained 50% by weight of polymeric components such as indene and coumaron, and contained indene. The amount is 37.3% by weight
The coal tar naphtha fraction and maleic anhydride are set at a molar ratio of the polymerization component and maleic anhydride to 1:1,
Azobisisobutyronitrile (1
A copolymer (number average molecular weight 6,400) obtained by reacting with 00 mol% maleic anhydride) was neutralized with sodium hydroxide to make an aqueous sodium salt solution of the copolymer, and (C) Sodium thiocyanate was used as a component.

70 parts by weight of the component (A) (in terms of solid content), 30 parts by weight of the component (B) (in terms of solid content), and 100 parts by weight of the component (C) (
(in terms of solid content) to obtain a cement dispersion composition.

A mortar test was conducted and evaluated using this cement dispersion composition.

Table 1 shows the composition of the mortar.

Add water, cement, and the above-mentioned cement dispersion composition (0.4% by weight to cement in terms of solid content) to a cement mixing bowl and mix for 30 seconds, then mix for 30 seconds while mixing sand.
Added in seconds and continued mixing for 600 minutes. The mixture was allowed to stand for 20 seconds, the mortar adhering to the mixing bee and paddle was scraped off, and then mixed again for 120 seconds.

After filling the obtained mortar into a mini-slump cone with a height of 15 cm, the mini-slump cone was removed and the slump was measured. Furthermore, after leaving the mortar for 60 minutes,
After mixing for a minute, the slump was measured in the same manner, and the residual slump rate (%) was determined from the following formula: 68.6%.

× 100 Also, the mortar hardening time (starting time) is 5 hours 50 minutes, 1
The daily strength was 82 Kg7cm2 and the 28 day strength after water curing was 418 Kg/cm2.

(Examples 2 to 5) A mortar test was conducted in the same manner as in Example 1 except for the component (C), and the results are shown in Table 2.

(Comparative Example 1) A mortar test was conducted in the same manner as in Example 1 except that component (C) was not used, and the results are shown in Table 2.

(Comparative Example 2) Example 1 except that component (B) and component (C) were not used.
A mortar test was conducted in the same manner as above, and the results are shown in Table 2.

(Comparative Example 3) A mortar test was conducted in the same manner as in Example 1 using triethanol as the main component (C), and the results are shown in Table 2.

<Effects of the Invention> Since the present invention is configured as described above, the cement dispersion composition of the present invention has high initial fluidity when used in a cement mixture, and has a low hardening delay and low initial strength. It is useful as an additive to cement mixtures such as ready-mixed concrete because it exhibits a small decrease in fluidity over time.

Claims (4)

[Claims] (1) A cement dispersion composition containing the following components (A), (B) and (C). (A) From alkali metal salts, alkaline earth metal salts, ammonium salts, and amine salts of compounds obtained by sulfonating an aromatic hydrocarbon oil containing naphthalene and/or alkylnaphthalene as a main component and then condensing it with formalin. At least one selected from the group consisting of (B) an alkali metal salt, alkaline earth metal salt, or ammonium salt of a copolymer of an olefin having 2 to 10 carbon atoms and an unsaturated dicarboxylic acid anhydride having an ethylenic double bond; and at least one compound selected from the group consisting of amine salts (C) one type or a mixture of two or more compounds selected from the group consisting of nitrites, thiosulfates, thiocyanates, and sulfates. (2) The cement dispersion composition according to claim 1, wherein the component (B) is present in an amount of 10 parts by weight or more based on 100 parts by weight of the component (A). (3) The cement dispersion composition according to claim 1, wherein the component (C) is present in an amount of 50 to 500 parts by weight based on 100 parts by weight of the component (B). (4) The cement dispersion composition according to any one of claims 1 to 3, wherein the olefin having 2 to 10 carbon atoms is a light oil containing indene as a main component.