JPH01176256A - Slump loss-diminishing type admixture and composition using same - Google Patents

Abstract

PURPOSE:To obtain the admixture useful as an additive to cement, mortar and concrete, capable of giving high initial fluidity and fluidity of little change with time, by combining each specific two kinds of reaction product salt. CONSTITUTION:(A) An aromatic hydrocarbon-contg. oil consisting mainly of naphthalene and/or alkylnaphthalene produced by e.g. distillation of coal tar is sulfonated with sulfuric acid followed by condensation with formalin and the elimination of the sulfuric acid left unreacted. Along with this, the resultant condensate is converted into its alkali (alkaline earth) metal salt, ammonium salt or amine salt. (B) (i) a light soil fraction with a boiling point of 150-250 deg.C produced by e.g. fractionation of coal tar, containing >=25wt.% of indene as the chief component and (ii) a unsaturated dicarboxylic anhydride having olefinic double bond (e.g. maleic anhydride) are copolymerized in the presence of an initiator to produce a copolymer mixture, which is converted into its alkali (alkaline earth) salt, ammonium salt or amine salt. Thence, 90pts.wt. of at least one kind of the group A and >=10pts.wt. of one kind of the group B are combined to obtain the title admixture.

Description

Detailed Description of the Invention <Field of Industrial Application> The present invention relates to an admixture for cement that hardens under the influence of water, and in particular to an admixture for fluidizing cement, mortar or concrete and reducing slump loss. This invention relates to a composition using the same.

<Prior Art> In order to improve the workability of cement, mortar, or concrete, it is necessary that the initial fluidity of the mixture of cement, water, and other substances is high, and that the fluidity does not change significantly over time.

It is known that changes in fluidity over time occur mainly due to hydration reactions between cement and water and physical aggregation between mixtures.

In cement, mortar, or concrete, due to the hydration reaction between cement and water, physical and chemical agglomeration of cement particles progresses over time after mixing, reducing fluidity and reducing workability and construction properties over time. decreases to This phenomenon is generally referred to as mortar flow reduction or concrete slump loss, and limits the pot life.

In the case of ready-mixed 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, changes over time in the fluidity of cement compounds such as cement, mortar, and concrete, that is, slump loss, is an important problem to be solved.

For this reason, several methods have been considered to prevent concrete slump loss.

(1) Japanese Patent Publication No. 51-15856 describes a concrete admixture 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 .Although this method is somewhat effective, it is laborious to add and not only does it have poor workability, but it is also economically unsatisfactory. It is disadvantageous.

(2) The method of adding a setting retarder such as oxycarboxylic acid causes a decrease in strength and poor curing. Also, although this method can delay the hydration reaction of cement, it is difficult to prevent physical agglomeration.

(3) JP-A No. 54-139929 discloses that a concrete admixture such as a naphthalene sulfonic acid formalin condensate is made into granules and added to concrete, etc., and the granular admixture is gradually dissolved. A method to prevent losses is shown.

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

(4) Furthermore, JP-A-60-11256 discloses an additive made of a saponified copolymer of styrene and maleic acid as a cement additive for preventing slump loss, but the amount When the amount is small, the effect of improving the fluidity of the cement composition is low, and it is also economically disadvantageous because it is manufactured from expensive raw materials.

As described above, conventional methods for preventing slump loss cannot be said to be practically sufficient.

<Objective of the Invention> An object of the present invention is to provide a novel slump loss-reducing admixture and a composition using the same, in order to solve the problems of conventional cement formulations as described above.

<Configuration of the Invention> That is, the first aspect of the present invention is an admixture for reducing slump loss of a cement mixture, which contains an aromatic hydrocarbon-containing oil containing naphthalene and/or alkylnaphthalene as a main component. At least one compound selected from the group consisting of alkali metal salts, alkaline earth metal salts, ammonium salts, and amine salts of a compound obtained by sulfonation and then condensation with formalin, a light oil containing indene as a main component, and an olefinic dihydride. and at least one selected from the group consisting of alkali metal salts, alkaline earth metal salts, ammonium salts, and amine salts of a copolymer mixture obtained by reaction with an unsaturated dicarboxylic acid anhydride having a double bond. A slump loss reducing admixture is provided.

A second aspect of the present invention provides a cement composition characterized by containing the following components.

■ Water ■ Cement ■ An admixture for reducing slump loss in cement formulations, which is obtained by sulfonating an aromatic hydrocarbon-containing 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 alkali metal salts, alkaline earth metal salts, ammonium salts, and amine salts of the compound;
Consists of alkali metal salts, alkaline earth metal salts, ammonium salts, and amine salts of a copolymer mixture obtained by the reaction of a light oil component mainly composed of indene and an unsaturated dicarboxylic acid anhydride having an olefinic double bond. At least one selected from the group.

A third aspect of the present invention provides a mortar composition characterized by containing the following components.

■Fine aggregate ■Water ■Cement ■An admixture for reducing slump loss in cement formulations, which is made by sulfonating an aromatic hydrocarbon-containing oil containing naphthalene and/or alkylnaphthalene as a main component, and then adding it to formalin. At least one selected from the group consisting of alkali metal salts, alkaline earth metal salts, ammonium salts, and amine salts of compounds obtained by condensation,
Consists of alkali metal salts, alkaline earth metal salts, ammonium salts, and amine salts of a copolymer mixture obtained by the reaction of a light oil component mainly composed of indene and an unsaturated dicarboxylic acid anhydride having an olefinic double bond. At least one selected from the group A fourth aspect of the present invention provides a concrete composition characterized by containing the following components:

■Fine aggregate ■Coarse aggregate ■Water ■Cement ■An admixture for reducing slump loss in cement formulations, which includes aromatic hydrocarbon-containing oils containing naphthalene and/or alkylnaphthalene as main components. at least one selected from the group consisting of alkali metal salts, alkaline earth metal salts, ammonium salts, and amine salts of the compound obtained by condensation with formalin, a light oil mainly composed of indene, and an olefinic compound. At least one selected from the group consisting of alkali metal salts, alkaline earth metal salts, ammonium salts, and amine salts of a copolymer mixture obtained by reaction with an unsaturated dicarboxylic acid anhydride having a bond.

The present invention will be explained in detail below. - (1) Admixture of the first embodiment The aromatic hydrocarbon-containing oil containing naphthalene and/or alkylnaphthalene as a main component used as one of the raw materials for the admixture of the present invention is an aromatic hydrocarbon-containing oil such as naphthalene, methylnaphthalene, etc. Although hydrogen may be used alone or in combination, from the viewpoint of cost, it is preferable to use a naphthalene oil fraction and a methylnaphthalene oil fraction obtained in a coal tar distillation process. The oil obtained by distilling these coal tars may be used as is or after various pretreatments.

These aromatic hydrocarbon-containing oils are sulfonated by conventional methods and then condensed with formalin.

The light oil containing indene as a main component used as the other raw material for the admixture of the present invention is heavy gas oil (hereinafter referred to as coal tar naphtha) with a boiling point range of about 150 to 250°C obtained in the distillation/fractionation process of coal tar. (commonly known as CN oil)
, a distillate obtained by removing benzene, toluene, xylene, etc. from coke oven gas light oil (commonly known as C9+ oil) and petroleum-based 09
The + fraction can be exemplified, and 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 contain coumaron, dicyclopentadiene, styrene, methylindene, and the like.
It may also 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.

Any method may be used to produce the copolymer mixture of the above-mentioned light oil containing indene as a main component and an unsaturated dicarboxylic acid anhydride having an olefinic double bond, but for example, coal tar naphtha fraction and maleic anhydride may be produced. is reacted under radical polymerization conditions in the presence or absence of a radical polymerization initiator to form a copolymer, which is neutralized using sodium hydroxide (NaO) to form the sodium salt of the copolymer mixture. is preferred.

The admixture of the present invention does not directly use the compound and copolymer mixture obtained by sulfonating the aromatic hydrocarbon-containing oil and then condensing it with formalin, but in order to quickly exhibit a dispersing effect and make it water-soluble, Each is used as a salt (hereinafter, the former salt will be referred to as component A and the latter salt as component B). That is, alkali metals, alkaline earth metals,
It is used as an ammonium or amine salt or a mixture of two or more thereof.

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

The blending ratio of component A and component B is 90 parts by weight of component A and B.
Preferably, the amount of the component is 10 parts by weight or more.

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.

(2) Cement Composition of Second Embodiment Examples of the cement used in the present invention include various hydraulic cements such as various Portland cements, mixed cements, and special cements.

The cement composition is obtained by adding water and the admixture described in (1) to the above cement.

The admixture is used in an amount of 0.01 to 1.0% by weight based on the cement, but 0.1 to 0.5% by weight is particularly preferred. If the amount added is less than 0.1% by weight, the initial slump value will be small, and if it exceeds 0.5% by weight, there will be little change in performance and only the economical efficiency will deteriorate.

The admixture may be added to the kneading water of the cement mixture, or it may be added to the thoroughly kneaded cement mixture.

(3) Mortar composition of the third aspect This is a mortar composition in which fine aggregate is further added to the cement composition described in (2) above.

Any type of fine aggregate may be used, but river sand passed through a 5 mm sieve is typically cited, and round-shaped aggregates are preferred.

(4) Concrete composition of the fourth aspect This is a concrete composition in which concrete aggregate is further added to the mortar composition described in (3) above.

Any type of coarse aggregate may be used, including gravel remaining in a 10 mm sieve.

The compositions (2), (3) and (4) above may contain various cement additives such as an AE agent, an AE water reducing agent, a hardening modifier, etc. in addition to the above components.

<Example> The present invention will be specifically explained below using Examples.

(Example 1) 128.0 g of naphthalene oil fraction obtained by distillation of coal tar (composition is shown in 1 of Table 1) was mixed with 1 part of 98% sulfuric acid.
40.0 g was added, and a sulfonation reaction was carried out at a reaction temperature of 150° C. and a reaction time of 3 hours.

Next, the obtained sulfonated product was diluted with water, 64.9 g of formalin was added, the reaction temperature was 100°C, and the reaction time was 16.
The condensation reaction was carried out for hours. Finally, unreacted sulfuric acid in the condensate was removed as gypsum by a liming sorption method to obtain a sodium salt aqueous solution of a sulfonic acid-formalin condensate of aromatic hydrocarbons (hereinafter referred to as A-1).

Separately, a coal tar naphtha fraction (containing about 50% by weight of polymerization components such as indene, and an indene content of 37.3% by weight) and maleic anhydride were mixed with a polymerization component of the coal tar naphtha fraction and anhydrous. In a molar ratio of 1:1 with maleic acid,
A copolymer mixture (average molecular weight of about 7
00) was neutralized using sodium hydroxide (NaOH) as a neutralizing agent to prepare an aqueous solution of the sodium salt of the copolymer mixture (hereinafter referred to as B-1) containing about 30% by weight.

A-1 and B-1 were mixed at a ratio of 8:2 and 5:5 (weight ratio in terms of solid content) to prepare an admixture of the present invention (Invention Examples 1 and 2).

(Example 2) Instead of the naphthalene oil fraction shown in 1 in Table 1, 2 in Table 1 was used.
The admixture of the present invention (invention example 3 and 4) was prepared.

(Example 3) Instead of the naphthalene oil fraction shown in 1 in Table 1, 3 in Table 1 was used.
The admixture of the present invention (invention example 5 and 6) were prepared.

(Example 4) Instead of the naphthalene oil fraction shown in 1 in Table 1,
The admixture of the present invention (Inventive Example 7 and 8) were prepared.

(Example 5) The sodium salt of naphthalene sulfonic acid formalin condensate, which is known as a commercially available fluidizing agent, was used instead of the sodium salt of sulfonic acid formalin condensate obtained from the naphthalene oil fraction shown in 1 of Table 1. Admixtures of the present invention (Inventive Examples 9 and 10) were prepared in the same manner as in Example 1, except for the following.

(Example 6) Except that the coal tar naphtha fraction was previously debased using sulfuric acid and then reacted with maleic anhydride to obtain an aqueous solution (B-2) of the sodium salt of the copolymer mixture. In the same manner as in Example 3, admixtures of the present invention (Inventive Examples 11 and 12) were prepared.

(Example 7) Admixtures of the present invention (Inventive Examples 13 and 14) were prepared in the same manner as in Example 6, except that A-4 was used instead of A-3.

The above admixtures of the present invention are shown in Table 2.

(Examples 8 to 14) 0.3% by weight of each of the above-mentioned admixtures of Invention Examples 1 to 14 was added to the cement in terms of solid content, and this was dissolved in water to make a total amount of 550 g. , 1000 g of ordinary Portland cement and 2000 g of mountain sand from Kisarazu were added, mixed for 1 minute using a mortar mixer, allowed to stand for 20 seconds, and mixed for another 2 minutes to obtain a mortar composition (
Invention Examples 15 to 28).

(Comparative Examples 1 to 5) Examples 8 to 14 except that the commercial products used in A-1, A-2, A-3, A-4, and Example 5 were used alone as admixtures. A mortar composition was prepared in the same manner as (Comparative Examples 1 to 5).

Evaluation Using the compositions of Examples 15 to 28 of the present invention and Comparative Examples 1 to 5 described above, fluidity and the effect of preventing changes in fluidity over time were examined.

The fluidity was evaluated by a small slump test (mortar) based on the slump test of JIS A 1101.

Compact slump test A mortar composition was tested in accordance with JIS A 1101 using a slump cone with a height of 15 cm.

The small slump test method is a suitable method for easily evaluating the fluidity etc. of various cement additives, and as shown in FIG. 1, it corresponds well to the results of the slump test according to JIS A 1101. Figure 1 shows J
It is a graph showing the correlation between the values of the IS A 1101 slump test and the small slump test.

For the change in slump over time, mortar-based compact slump test method was used because it shows the difference more clearly.

The evaluation results are shown in Table 3. In addition, 0 minutes after and 60 minutes in Table 3 are the slump values measured immediately after forming the mortar composition, and after that, leaving it to stand for 60 minutes and kneading it again for 1 minute. Further, the slump residual rate (%) is a value calculated using the following formula.

Table 1 Naphthalene oil fraction and methylnaphthalene oil fraction Table 2 Admixtures <Effects of the invention> The novel admixtures of the present invention have high initial fluidity when used in cement formulations, and show no change in fluidity over time. Because it is small, it is useful as an additive to cement formulations such as ready-mixed concrete.

Since the cement compositions, mortar compositions, and concrete compositions of the present invention use the above-mentioned admixtures, they have the advantage of having high initial fluidity and little change in fluidity over time.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the correlation between the values of the JIS slump test and the values of the small slump test.

Claims (4)

[Claims] (1) An admixture for reducing slump loss in cement formulations, which is a compound obtained by sulfonating an aromatic hydrocarbon-containing oil whose main component is naphthalene and/or alkylnaphthalene, and then condensing it with formalin. at least one selected from the group consisting of alkali metal salts, alkaline earth metal salts, ammonium salts and amine salts, and an unsaturated dicarboxylic acid anhydride having a light oil component mainly composed of indene and an olefinic double bond. A slump loss reducing admixture comprising at least one selected from the group consisting of alkali metal salts, alkaline earth metal salts, ammonium salts and amine salts of a copolymer mixture obtained by reaction. (2) A cement composition characterized by containing the following components. [1] Water [2] Cement [3] An admixture for reducing slump loss in cement formulations, which comprises sulfonating an aromatic hydrocarbon-containing oil containing naphthalene and/or alkylnaphthalene as a main component, and then At least one selected from the group consisting of alkali metal salts, alkaline earth metal salts, ammonium salts, and amine salts of compounds obtained by condensation with formalin, a light oil component mainly composed of indene, and an olefinic double bond. At least one selected from the group consisting of alkali metal salts, alkaline earth metal salts, ammonium salts, and amine salts of a copolymer mixture obtained by reaction with an unsaturated dicarboxylic acid anhydride. (3) A mortar composition characterized by containing the following components. [1] Fine aggregate [2] Water [3] Cement [4] An admixture for reducing slump loss of cement mixtures, containing aromatic hydrocarbons mainly consisting of naphthalene and/or alkylnaphthalene. At least one selected from the group consisting of alkali metal salts, alkaline earth metal salts, ammonium salts, and amine salts of compounds obtained by sulfonating oil and then condensing it with formalin, a light oil containing indene as a main component, and olefins. At least one selected from the group consisting of alkali metal salts, alkaline earth metal salts, ammonium salts, and amine salts of a copolymer mixture obtained by reaction with an unsaturated dicarboxylic acid anhydride having a polyvalent double bond. (4) A concrete composition characterized by containing the following components. [1] Fine aggregate [2] Coarse aggregate [3] Water [4] Cement [5] An admixture for reducing the slump loss of cement mixtures, which mainly contains naphthalene and/or alkylnaphthalene. The main components are at least one selected from the group consisting of alkali metal salts, alkaline earth metal salts, ammonium salts and amine salts of compounds obtained by sulfonating aromatic hydrocarbon-containing oil and then condensing with formalin, and indene. selected from the group consisting of alkali metal salts, alkaline earth metal salts, ammonium salts and amine salts of a copolymer mixture obtained by the reaction of a light oil component with an unsaturated dicarboxylic acid anhydride having an olefinic double bond. at least one