JP3281651B2 - Foaming agent composition for lightweight cellular concrete - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foaming agent composition for lightweight cellular concrete containing aluminum powder, and more particularly, it can control the expansion reaction of a raw material mortar slurry without lowering the foaming efficiency, and is stable in storage. The present invention relates to a foaming agent composition for lightweight cellular concrete having excellent properties.

[0002]

2. Description of the Related Art Conventionally, lightweight cellular concrete is manufactured as follows. First, calcareous material powder such as quicklime and Portland cement, and siliceous material powder such as silica stone,
After aluminum powder is added to the mortar slurry to which water and other materials are added, the aluminum powder is poured into a mold, and the mortar slurry is subjected to hydrogen gas generated by a reaction between calcium hydroxide and aluminum powder generated by hydrolysis of calcareous material. Inflate.

Then, the expanded mortar slurry gradually solidifies as the hydration reaction of the siliceous material progresses, and becomes a multi-cellular solidified body having discontinuous cells inside, that is, a semi-cured body. Next, this is autoclaved and cured to obtain a product.

[0004]

In the above-mentioned production process, the starting time and the rate of hydrogen gas generation are strongly affected by external conditions of the mortar slurry, particularly the temperature and the firing conditions of the raw quicklime. That is, as the temperature of the mortar slurry increases, the reaction becomes more aggressive. In general, the reaction of mortar slurry using calcined lime fired with heavy oil is more rapid than that using lime calcined with lime. Therefore, for example, in summer when the temperature is high, hydrogen gas is generated immediately when the aluminum powder is mixed into the mortar slurry, and the expansion starts before flowing into the mold, and the expansion becomes rapid. Not only do not obtain the desired foamed coagulated body, but also the expansion and coagulation reaction of the mortar slurry proceeds in the transport pipe to the mold, causing various troubles in the manufacturing process such as clogging the pipe. . A similar trouble also occurs when quick lime, which has a fast digestion rate, for example, burned with heavy oil is used at normal temperature. this is,
The heat generated by the digestion of quicklime promotes the reaction between the aluminum powder and calcium hydroxide.

[0005] Further, if a sudden expansion reaction starts before the mortar slurry is injected into the mold, there is a problem that the appearance quality of the final product is deteriorated. The cause of these troubles is that the hydrogen gas generation start time due to the reaction between the aluminum powder and the mortar slurry is too short. On the other hand, in order to improve the productivity of lightweight cellular concrete, it is necessary to accelerate the expansion and solidification reaction of the mortar slurry. Therefore, instead of conventional ordinary Portland cement,
Attempts have been made to increase the hardening rate of the mortar slurry by using high-strength Portland cement of alumina cement or the like. In this case, it is necessary to promote the generation of hydrogen gas by the reaction between the aluminum powder and the mortar slurry in accordance with such a curing speed. However, at present, conventional aluminum powder cannot be put to practical use because the generation rate of hydrogen gas is too slow.

Conventionally, aluminum powder used as a foaming agent for lightweight cellular concrete has been subjected to further heat treatment of dry-ground aluminum powder using fatty acids such as stearic acid as a grinding aid to remove fatty acids which inhibit water dispersibility. It is manufactured by. However, in the aluminum powder produced by this method, the reaction between the aluminum powder and the mortar slurry (calcium hydroxide) is too rapid, so that the generation of hydrogen gas before injection into the mold cannot be sufficiently controlled. Further, there is a danger of ignition or explosion of the aluminum powder during the heat treatment in the above method, and there is a problem in handling. In order to improve the productivity of lightweight aerated concrete, it is necessary to atomize the aluminum powder so as to increase the hydrogen gas generation rate by the reaction between the aluminum powder and the mortar slurry. The law limits its use in terms of danger.

On the other hand, aluminum powder produced by a wet grinding method in which a fatty acid or a derivative thereof is produced as a grinding aid in a petroleum-based solvent can be finely divided into particles more safely than the production method involving the above-mentioned heat treatment step. Even when a surfactant is added to impart water dispersibility, there is a problem in sufficient water dispersibility and stability during storage due to a large amount of a petroleum solvent.

Further, in order to suppress unnecessary reaction between the aluminum powder and the mortar slurry before pouring the mold,
It is known to add various reaction inhibitors to aluminum powder. However, if the reaction is suppressed by such a method, there is a problem that the expansion reaction after injection of the mold is generally suppressed and a satisfactory final product cannot be obtained. Therefore, the present invention solves such problems in the conventional foaming agent composition for lightweight cellular concrete, can control the reaction between aluminum powder and mortar slurry, is excellent in water dispersibility and storage stability, and is manufactured. An object of the present invention is to provide a foaming agent composition that does not cause any trouble in the process.

[0009]

In order to achieve the above object of the present invention, a foaming agent composition is used which comprises a surface treatment agent which is firmly adsorbed on the surface of aluminum powder, does not desorb even when dispersed in water, and has hydrophobicity. To the aluminum powder, thereby making the aluminum powder a coated state, and at the same time, wetting the hydrophobic surface so that the individual aluminum powder particles can be uniformly dispersed without adversely affecting the water as a dispersion medium. There are two points of improvement and imparting water dispersibility.

The present inventors have conducted intensive studies to overcome the above-mentioned requirements, and as a result, have found that an organophosphate compound having a melting point of 30 ° C. or more and containing at least one or two acidic OH groups is added to the surface of aluminum powder. Used as a treating agent, and a nonionic surfactant and alcoholic OH
It has been found that the combined use of a solvent containing a group is most effective, and the present invention has been completed.

That is, the foaming agent composition for lightweight cellular concrete of the present invention has a melting point of 30 ° C. or more and at least one or two acidic OH groups per 100 parts by weight of aluminum powder and the aluminum powder. Containing 0.5 to 15 parts by weight of an organic phosphate compound having 1 to 15 parts by weight of a nonionic surfactant, 5 to 70 parts by weight of a solvent containing an alcoholic OH group, and 0 to 70 parts by weight of a hydrocarbon solvent It is characterized by doing.

The aluminum powder used in the present invention is pulverized by a conventional pulverization method (wet and dry pulverization methods) and is conventionally used as a foaming agent for lightweight cellular concrete. Aluminum powder produced by a wet grinding method, which is crushed in a solvent, is suitable. As the particle size of such aluminum powder, it is preferable that the average particle size is 40 μm or less and the maximum particle size is 150 μm or less.

The organic phosphate compound used in the present invention has a melting point of 30 ° C. or more and has one or two acidic OH groups. When the temperature is lower than 30 ° C., the organophosphate compound is easily desorbed when the foaming agent composition is dispersed in water or mixed with the mortar slurry, and the reaction between the aluminum powder and the mortar slurry before the injection of the mold (hydrogen gas generation) Control) is insufficient, which adversely affects the quality of the final product. The melting point is more preferably 40 ° C. or higher in consideration of the summer temperature.

Although the number of acidic OH groups is one or two as described above, a mixture of compounds having one or two may be used. When the acidic OH group has three (phosphoric acid), the hydrophobicity is insufficient and the effect of suppressing the reaction is poor. On the other hand, acidic OH
When it does not have a group, strong adsorption is not performed on the surface of the aluminum powder, and there is almost no effect of suppressing the reaction. As such an organic phosphate compound, for example, a compound having 14 carbon atoms
To 24, preferably an ester of a saturated alkyl alcohol having 18 to 24 carbon atoms. Specific examples include organic phosphate compounds such as tetradecyl, cetyl, octadecyl, aralkyl, behenyl, and carnaubavir. These may be used alone or in a mixture thereof.

Further, an alkylene oxide may be added to these organic phosphate compounds, for example, 0 to 10 mol per molecule of the organic phosphate compound.
To which ethylene oxide or propylenoxide is added. The amount of the organic phosphoric acid ester compound to be added is 0.1 to 100 parts by weight of the aluminum powder.
It is preferably 5 to 15 parts by weight, more preferably 2 to 10 parts by weight.
Parts by weight are good. If the amount is less than 0.5 part by weight, the surface of the aluminum powder cannot be sufficiently covered, and the reaction suppressing effect is poor,
When the amount exceeds 15 parts by weight, there is an effect of suppressing the reaction, but the reaction is suppressed more than necessary even after injection of the mold, so that the expansion reaction is slowed down, and the mortar slurry solidifies before sufficient hydrogen gas is generated. It is not preferable because the quality of the product is reduced.

The mechanism of action of the organophosphate compound in the composition of the present invention is not clear, but according to the study of the present inventors, it is estimated as follows. That is, the organic phosphate compound is adsorbed on the surface of the aluminum powder to form a protective film having high hydrophobicity. At this time, the acidic OH group contributes to the adsorption on the surface of the aluminum powder. The aluminum powder forming the protective film having high hydrophobicity temporarily suppresses the reaction with calcium hydroxide dissolved in the mortar slurry. However, as time passes, the calcium ion concentration in the liquid phase increases due to hydrolysis of the calcareous material, and the temperature of the mortar slurry rises due to the heat of hydration. I do. As a result, the exposed aluminum powder reacts with calcium hydroxide to generate hydrogen gas. Thus, although the reaction with calcium hydroxide of time only aluminum powder and mortar slurry until desorption dissolved hydrophobic protective film of an organic phosphoric acid ester compound is inhibited, then to transition to a good response < br />

The method for adding the organic phosphate compound to the aluminum powder is not particularly limited. In general, in the method for producing aluminum powder, a raw material atomized powder or aluminum foil powder is fed into a pulverizer such as a ball mill or an attritor, and a pulverization auxiliary agent for increasing the pulverization efficiency is added, for example, in an organic solvent. Wet grinding method,
Alternatively, a dry pulverization method in a nitrogen atmosphere is used. Preferred grinding aids at this time include stearic acid, palmitic acid, aliphatic carboxylic acids such as oleic acid, stearylamine, aliphatic amines such as oleylamine, stearyl alcohol, aliphatic alcohols such as lauryl alcohol, oleic acid amide, Aliphatic amides such as stearylamide and lauric amide;

When an aliphatic carboxylic acid, an aliphatic amine, an aliphatic alcohol, an aliphatic amide and the like are added and pulverized in this way, aluminum powder surface-treated with them is obtained. The organic phosphate compound can be added later and further mixed by a mixer or the like to form a protective film of the organic phosphate compound on the surface of the aluminum powder. However, it is also possible to pulverize aluminum powder by simultaneously adding an aliphatic amide or the like and an organic phosphoric acid compound.

In the present invention, as a surfactant for measuring water dispersibility, a nonionic surfactant is used from the viewpoint of storage stability, and specific examples thereof include polyoxyethylene alkyl ether and polyoxyethylene alkyl phenol ether. And polyethylene glycol fatty acid esters. These may be added together with the organic phosphate compound in the mixing step, or may be added and mixed after the treatment with the organic phosphate compound.

The addition amount of the nonionic surfactant is 1 to 15
Parts by weight, preferably 2 to 10 parts by weight. If the amount is less than 1 part by weight, desired water dispersibility cannot be obtained. On the other hand, when the amount exceeds 15 parts by weight, hydrogen gas pools are easily generated in the mold during the expansion reaction of the mortar slurry, which is not preferable because the appearance of the final product is deteriorated. The HLB of a preferred nonionic surfactant is from 6 to 16, more preferably from 8 to 13. If it is less than 6, the lipophilicity of the surfactant increases, and the water dispersibility of the composition decreases.
On the other hand, if it exceeds 16, the water solubility of the surfactant becomes too high, and the water dispersibility of the composition similarly decreases.

As the solvent containing an alcoholic OH group used in the present invention, a solvent having the property of dissolving or dispersing in an appropriate ratio with a hydrocarbon solvent and water and not dissolving an organic phosphate compound is used. Is preferred. Its content is 5 to 7 parts per 100 parts by weight of aluminum powder.
0 parts by weight, preferably 20 to 55 parts by weight. If the amount is less than 5 parts by weight, the water dispersibility and the stability over time of the water dispersibility are poor, and if it exceeds 70 parts by weight, the expansion reaction of the mortar slurry is hindered and the final product is adversely affected. In addition, the solvent odor becomes strong, leaving a problem in the working environment.

Specific examples of the solvent containing an alcoholic OH group include polyoxyethylene glycol, polyoxypropylene glycol, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether,
Examples thereof include diethylene glycol / monobutyl ether, tripropylene glycol / monomethyl ether, ethoxypropanol, isopropanol, isobutanol, isoamyl alcohol, ethanol, and methyl isobutyl carbinol, and these can be used in combination.

The hydrocarbon solvent in the present invention may be used as desired. For example, mineral spirits, solvent naphtha, LAWS, and the like generally used for wet milling are used.
Aliphatic Keia Rui such HAWS can be appropriately used hydrocarbons such aromatic. The used amount is 0 to 70 parts by weight, preferably 0 to 100 parts by weight of aluminum powder.
４０40 parts by weight. If it exceeds 70 parts by weight, the water dispersibility of the composition and the stability over time of the water dispersibility become too poor, which is not preferable. The content of the hydrocarbon-based solvent depends on the content of the solvent containing an alcoholic OH group,
By the ratio of both solvents, the water dispersibility of the composition and the temporal stability of the water dispersibility are maintained. When the weight of the solvent containing the alcoholic OH group is A and the weight of the hydrocarbon solvent is B, the ratio of the two solvents is preferably B / A of 4 or less, more preferably B / A of 2 or less. To be. When B / A exceeds 4, the hydrophilicity of the composition decreases, and as a result, the water dispersibility deteriorates and the temporal stability of the water dispersibility also deteriorates.

[0024]

EXAMPLES Examples of the present invention and comparative examples are shown below. A mixture of 10 kg of granular aluminum powder and 10 kg of mineral spirit containing 5% by weight of stearic acid is pulverized in a ball mill for 8 hours, and then diluted with 20 kg of mineral spirit and transferred to a slurry tank.
Filter with a filter press. The filter press cake thus obtained had a metal content of 90% by weight and a mineral spirit of 10% by weight, and the sieve residue in a preparation sieve having an opening of 149 μ was less than 0.1%.

The metal content of this filter press cake is 10
As shown in Table 1, a predetermined amount of an organic phosphate compound, a nonionic surfactant, and an alcoholic OH group-containing solvent were added to 0 parts by weight so that the heating residue became 65%. Of the present invention was obtained. For comparison with the present invention, various blowing agent compositions were prepared using the compositions shown in Table 2 in exactly the same manner as the above.

With respect to each of the foaming agent compositions obtained in Examples and Comparative Examples, the water dispersibility, the stability over time of water dispersibility, and the foaming property were examined. The results are shown in Tables 1, 2 and 1. Indicated. In FIG. 1, reference numerals 15, 16 and 17 are respectively
And Comparative Examples 1, 2 and 3 are shown. The test methods performed are as follows. (1) Water dispersibility: 3 kg of a sample is collected in a 50 ml Nessler tube, and a small amount of water is added for preliminary dispersion. After that, 50
Add water up to the ml mark line, shake well, and leave still
It is visually determined from the dispersion state of the aluminum particles after a lapse of minutes.

◎ Uniformly dispersed ○ Almost uniformly dispersed ゝ or ゝ Aggregated × considerably agglomerated (2) Stability with time of water dispersibility: 200 g of sample was 300 m
1 Place in a tin can, seal, and check the water dispersibility after storage at 40 ° C. for one month. (3) Foamability: 140 g of Portland cement, 2 silica stones
A mortar slurry for lightweight cellular concrete composed of 20 g, quick lime 40 g and water 220 g was heated at a predetermined temperature (Table 1).
After the preparation of the mortar slurry, a predetermined amount of a foaming agent composition containing 0.3 g as a metal component is added to and mixed with the mortar slurry as an aqueous dispersion in which a small amount of water is dispersed in advance to start foaming. The rising height of the slurry was measured over time.

The time from when the foaming agent composition was introduced into the mortar slurry to when the mortar slurry started to rise was measured and defined as "foaming start time (min)", which was 30 minutes based on the mortar slurry volume before expansion. The percentage of the subsequent expansion volume was defined as the “expansion rate (%)” of the mortar slurry. "Expansion start time""Expansionrate" ◎ 6 minutes or more ◎ 90% or more ○ 2 or more to less than 6 minutes ○ 80% or more to less than 90% × less than 2 minutes × less than 80% From the results of Table 2 and FIG. When an organic phosphate compound different from the present invention is used, expansion starts immediately after the addition of the foaming agent, and the foaming start time is too short. on the other hand,
By increasing the amount of the organic phosphoric acid ester compound added, the foaming start time is prolonged, but the foaming efficiency of the mortar slurry is significantly reduced and the expansion rate is deteriorated.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

As described above, by adding the blowing agent composition of the present invention to the mortar slurry for lightweight cellular concrete, the initial expansion of the mortar slurry due to the generation of hydrogen gas can be suppressed, and Good foaming properties can be exhibited without lowering the foaming efficiency of the mortar slurry. Furthermore, even at a high temperature, or in the case of using quicklime having different sintering conditions or cement having a different setting speed, it is possible to produce industrially extremely effective lightweight cellular concrete.

In addition, the blowing agent composition of the present invention can be dispersed extremely easily and uniformly in water, which is a main dispersion medium in a mortar slurry, and has excellent storage stability over a long period of time. And the same good water dispersibility and foaming properties as in the initial stage after storage can be obtained.

[Brief description of the drawings]

FIG. 1 is a graph showing expansion coefficient curves of mortar slurries of Examples and Comparative Examples of the present invention.

────────────────────────────────────────────────── (5) References JP-A-55-158202 (JP, A) JP-A-56-166309 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C04B 38/02

Claims (1)

(57) [Claims] 1. An aluminum phosphate and 0.5 to 15 parts by weight of an organic phosphoric ester compound having a melting point of 30 ° C. or more and having one or two acidic OH groups per 100 parts by weight of said aluminum powder, nonionic Surfactant 1-15
A foaming agent composition for lightweight cellular concrete, comprising: 5 parts by weight, 5 to 70 parts by weight of a solvent containing an alcoholic OH group, and 0 to 70 parts by weight of a hydrocarbon solvent.