JPH06122573A - Forming agent composition for lightweight cellular concrete - Google Patents

Abstract

PURPOSE:To suppress the initial foaming without deteriorating the foaming efficiency of a mortar slurry for lightweight cellular concrete. CONSTITUTION:The objective composition comprises 100 pts.wt. aluminum powder, 0.5-15 pts.wt. organic phosphoric acid ester compound having >=30 deg.C melting point and 1 or 2 acidic OH groups, 1-15 pts.wt. nonionic surfactant, 5-70 pts.wt. solvent having alcoholic OH group and 0-70 pts.wt. hydrocarbon- based solvent.

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 particularly, it is possible to control the expansion reaction of a raw material mortar slurry without lowering the foaming efficiency and to stabilize the storage stability. 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 adding aluminum powder to mortar slurry containing water and other materials, pour it into a molding form and use hydrogen gas produced by the reaction between calcium hydroxide and aluminum powder generated by hydrolysis of calcareous material to produce the mortar slurry. 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-hardened body. Next, this is autoclaved and cured to obtain a product.

[0004]

In the above manufacturing process, the starting time and rate of hydrogen gas generation are strongly influenced by the external conditions of the mortar slurry, particularly the temperature and the firing conditions of the raw quicklime. That is, when the temperature of the mortar slurry increases, the reaction thereof becomes abrupt, and in general, the reaction of mortar slurry using quick lime burned with heavy oil is more rapid than that of the one using quick lime burnt with lime. Therefore, for example, in summer when the temperature is high, hydrogen gas is generated immediately when aluminum powder is mixed in the mortar slurry, and expansion starts before it is poured into the molding form, and the expansion becomes rapid, so that hydrogen gas is discharged outside the system. Occurs, not only the desired foamed solidified body is not obtained, but also the expansion and solidification reaction of the mortar slurry progresses in the transport pipe to the molding form, causing various troubles in the manufacturing process such as clogging the pipe. . The same trouble occurs when quick digestion speed, for example, quick lime of heavy oil firing is used at room temperature. this is,
This is based on the fact that the heat generated by digestion of quicklime promotes the reaction between aluminum powder and calcium hydroxide.

Further, if a rapid expansion reaction is started before the mortar slurry is poured 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. So, instead of conventional ordinary Portland cement,
It has been attempted to accelerate the hardening rate of the mortar slurry by using early-strength Portland cement such as alumina cement. In this case, it becomes necessary to accelerate the hydrogen gas generation due to the reaction between the aluminum powder and the mortar slurry in accordance with such a curing speed. However, the 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 is subjected to further heat treatment of dry-ground aluminum powder using a fatty acid such as stearic acid as a grinding aid to remove the fatty acid which impairs 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 hydrogen gas generation before injection into the mold cannot be sufficiently controlled. Further, in the above method, there is a risk of ignition and explosion of aluminum powder during heat treatment, which is a handling problem. In order to improve the productivity of lightweight cellular 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, the aluminum powder produced by the wet pulverization method in which a fatty acid or its derivative is produced as a pulverization aid in a petroleum solvent can be made into fine particles more safely than the production method which goes through the above heat treatment step. Even if a surfactant is added to impart water dispersibility, there is a problem in sufficient water dispersibility and storage stability because it contains a large amount of petroleum solvent.

Further, for the purpose of suppressing 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 generally a problem that even the expansion reaction after the mold injection is 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 the aluminum powder and the mortar slurry, is excellent in water dispersibility and storage stability, and is manufactured. It is an object of the present invention to provide a foaming agent composition which does not cause any trouble in the process.

[0009]

In order to achieve the above-mentioned object of the present invention, a surface treatment agent which is strongly adsorbed on the surface of aluminum powder, does not desorb even when dispersed in water, and has hydrophobicity is used as a foaming agent composition. The aluminum powder in a coated state, and the wettability of the hydrophobic surface is ensured so that the individual aluminum powder particles can be uniformly dispersed without adversely affecting the dispersion medium water. Two points are required to improve and provide water dispersibility.

As a result of intensive studies conducted by the present inventors in order to overcome the above-mentioned requirements, the surface of aluminum powder was treated with an organic phosphate compound having a melting point of 30 ° C. or higher and containing at least one or two acidic OH groups. Used as a treatment agent, nonionic surfactant and alcoholic OH
It has been found that it is most effective to use a solvent containing a group together, 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 higher and at least one or two acidic OH groups per 100 parts by weight of the aluminum powder. Contains 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 40 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 usual pulverizing method (wet and dry pulverizing method) and has been conventionally used as a foaming agent for lightweight cellular concrete. Aluminum powder produced by a wet grinding method, which is ground in a solvent, is suitable. Regarding 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 phosphoric acid ester compound used in the present invention has a melting point of 30 ° C. or higher and has one or two acidic OH groups. When the temperature is lower than 30 ° C., the organic phosphate ester compound is easily desorbed at the time of dispersing the foaming agent composition in water or mixing with the mortar slurry, and suppresses the reaction between the aluminum powder and the mortar slurry before injecting the mold (generation of hydrogen gas). Control) is insufficient and the quality of the final product is adversely affected. The melting point is more preferably 40 ° C. or higher in consideration of the summer temperature.

The number of acidic OH groups is one or two as described above, but a mixture of compounds having the one or two acidic OH groups may be used. When the number of acidic OH groups is 3 (phosphoric acid), the hydrophobicity is insufficient and the reaction suppressing effect is poor. On the other hand, acidic OH
When it does not have a group, it is not strongly adsorbed on the surface of the aluminum powder, and there is almost no reaction suppressing effect. Examples of such an organic phosphate compound include, for example, 14 carbon atoms.
-24, preferably an organic phosphate ester compound which is an ester of a saturated alkyl alcohol having 18 to 24 carbon atoms can be used. Specific examples thereof include organic phosphate compounds such as tetradecyl, cetyl, octadecyl, aralkyl, behenyl, and carnavir. These may be used alone or as a mixture thereof.

Further, an alkylene oxide can be added to these organic phosphoric acid ester compounds, for example, 0 to 10 mol per molecule of the organic phosphoric acid ester compound.
Ethylene oxide or propylenoxide is added. The addition amount of the organic phosphoric acid ester compound was 0.
5 to 15 parts by weight is preferable, and more preferably 2 to 10 parts.
Good parts by weight. If it is less than 0.5 parts by weight, the surface of the aluminum powder cannot be sufficiently covered and the reaction suppressing effect is poor.
If it exceeds 15 parts by weight, the reaction is suppressed, but the expansion reaction is delayed because the reaction is suppressed more than necessary even after the mold is injected, and the mortar slurry solidifies before hydrogen gas is sufficiently generated. This is not preferable because the quality of the product deteriorates.

The mechanism of action of the organophosphate compound in the composition of the present invention is not clear, but it is presumed as follows according to the studies by the present inventors. That is, the organic phosphoric acid ester compound is adsorbed on the surface of the aluminum powder to form a highly hydrophobic protective film, and at that time, the acidic OH group contributes to the adsorption on the surface of the aluminum powder. Thus, the aluminum powder forming the highly hydrophobic protective film temporarily suppresses the reaction with the calcium hydroxide dissolved in the mortar slurry. However, when the calcium ion concentration in the liquid phase increases due to the hydrolysis of the calcareous material with the passage of time and the temperature of the mortar slurry rises due to the heat of hydration, the protective film gradually dissolves and finally completely destroys. To do. As a result, the exposed aluminum powder reacts with calcium hydroxide to generate hydrogen gas. Therefore, the reaction between the aluminum powder and the calcium hydroxide in the mortar slurry is suppressed only for the time until the hydrophobic protective film of the organic phosphate ester compound is dissolved and desorbed, but thereafter, it shifts to a good reaction.

The method for adding the organophosphate compound to the aluminum powder is not particularly limited. In general, the method for producing aluminum powder is such that, in a pulverizer such as a ball mill or an attritor, a raw material atomized powder or aluminum foil powder is added, and a pulverizing auxiliary agent for increasing the pulverization efficiency is added, for example, in an organic solvent. Wet grinding method,
Alternatively, a dry grinding method or the like in a nitrogen atmosphere is used. As a preferable grinding aid at this time, stearic acid, palmitic acid, aliphatic carboxylic acid such as oleic acid, stearylamine, aliphatic amine such as oleylamine, stearyl alcohol, aliphatic alcohol such as lauryl alcohol, oleic acid amide, Examples include aliphatic amides such as stearyl acid amide and lauric acid amide.

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

In the present invention, a nonionic surfactant is used as a surfactant for achieving water dispersibility from the viewpoint of storage stability. Specifically, polyoxyethylene alkyl ether and polyoxyethylene alkylphenol ether are used. , Polyethylene glycol fatty acid ester, etc. These may be added together with the organic phosphate ester compound in the mixing step, or may be added and mixed after the treatment with the organic phosphate ester compound.

The amount of the nonionic surfactant added is 1 to 15
Parts by weight, preferably 2 to 10 parts by weight. If it is less than 1 part by weight, desired water dispersibility cannot be obtained. On the other hand, if the amount exceeds 15 parts by weight, hydrogen gas is likely to be accumulated in the mold during the expansion reaction of the mortar slurry, which deteriorates the appearance of the final product, which is not preferable. The preferred nonionic surfactant has an HLB of 6 to 16, and more preferably 8 to 13. When it is less than 6, the lipophilicity of the surfactant is increased and the water dispersibility of the composition is lowered.
On the other hand, if it exceeds 16, the water solubility of the surfactant becomes too high, so that the water dispersibility of the composition similarly decreases.

The alcoholic OH group-containing solvent used in the present invention has the ability to dissolve or disperse in a suitable ratio with a hydrocarbon solvent and water, and does not dissolve the organic phosphate compound. Is preferred. The content is 5 to 7 with respect to 100 parts by weight of aluminum powder.
It is 0 part by weight, preferably 20 to 55 parts by weight. If it is less than 5 parts by weight, the water dispersibility and the stability of water dispersibility with time are inferior, 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 work 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,
Diethylene glycol / monobutyl ether, tripropylene glycol / monomethyl ether, ethoxypropanol, isopropanol, isobutanol, isoamyl alcohol, ethanol, methylisobutylcarbinol and the like can be mentioned, and these can also be used as a mixture.

The hydrocarbon solvent used in the present invention is optionally used. For example, mineral spirits, solvent naphtha, LAWS, which are generally used for wet grinding,
Aliphatic or aromatic hydrocarbons such as HAWS can be appropriately used. The amount used is 0 to 70 parts by weight, preferably 0 to 40 parts by weight, based on 100 parts by weight of the aluminum powder. If it exceeds 70 parts by weight, the water dispersibility of the composition and the temporal stability of the water dispersibility become too poor, which is not preferable. The content of hydrocarbon solvent is
Depending on the content of the solvent containing an alcoholic OH group, the water dispersibility of the composition and the temporal stability of the water dispersibility are maintained depending on the ratio of both solvents. When the weight of the solvent containing an alcoholic OH group is A and the weight of the hydrocarbon solvent is B, the ratio of both solvents is preferably B.
/ A is 4 or less, and more preferably B / A is 2 or less. When B / A exceeds 4, the hydrophilicity of the composition decreases, and as a result, the water dispersibility deteriorates and the stability of the water dispersibility with time also deteriorates.

[0024]

EXAMPLES Examples and comparative examples of the present invention will be shown below. A mixture of 10 kg of granular aluminum powder and 10 kg of mineral spirit containing 5% by weight of stearic acid was crushed in a ball mill for 8 hours, then 20 kg of mineral spirit was added to dilute, and then 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 on the preparatory sieve having an opening of 149μ was 0.1% or less.

Metal content of this filter press cake 10
As shown in Table 1, various organic phosphoric acid ester compounds, a nonionic surfactant, and an alcoholic OH group-containing solvent were added to 0 parts by weight so that the heating residue became 65%. The foaming agent composition of the present invention was obtained. For the purpose of comparison with the present invention, various foaming agent compositions were prepared in the same manner except that the compositions shown in Table 2 were used.

With respect to the respective foaming agent compositions obtained in Examples and Comparative Examples, water dispersibility, stability of water dispersibility with time, and foamability were examined, and the results are shown in Table 1, Table 2 and FIG. Indicated. The test method used is as follows. (1) Water dispersibility: A sample of 3 kg is sampled in a 50 ml Nessler tube, and a small amount of water is added to carry out preliminary dispersion. After that, 50
Add water up to the ml mark, shake well and let stand 5
It is visually judged from the dispersed state of the aluminum particles after a lapse of minutes.

◎ Disperse uniformly ○ Disperse almost uniformly △ or "Agglomerate" × Aggregate considerably (2) Stability of water dispersibility with time: 300 m of 200 g of sample
1 Place in a tin can, seal, and store for 1 month at 40 ° C., and then check the water dispersibility. (3) Foamability: 140 g of Portland cement, silica stone 2
A mortar slurry for lightweight cellular concrete consisting of 20 g, quick lime 40 g, and water 220 g was prepared at a predetermined temperature (Table 1).
(See the above), a predetermined amount of the foaming agent composition containing 0.3 g as a metal component is added and mixed as a water dispersion liquid in which a small amount of water is previously added to the mortar slurry to start foaming, and mortar is added. The rising foam height of the slurry was measured over time.

The time from when the foaming agent composition was added to the mortar slurry until when the mortar slurry started to rise was defined as "foaming start time (min)", which was 30 minutes with respect to the volume of the mortar slurry before expansion. The percentage of the expanded volume afterward was defined as the "expansion rate (%)" of the mortar slurry. "Bubbling start time""Expansionrate" ◎ 6 minutes or more ◎ 90% or more ○ 2 or more and less than 6 minutes ○ 80% or more and less than 90% × less than 2 minutes × less than 80% From the results of Table 2 and Fig. 1, When an organophosphate compound different from that of the present invention is used, expansion starts immediately when a foaming agent is added, and the foaming start time is too short. on the other hand,
Although the foaming start time is lengthened by increasing the addition amount of the organic phosphate ester compound, the foaming efficiency of the mortar slurry is remarkably lowered and the expansion coefficient is deteriorated.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

As described above, by adding the foaming agent composition of the present invention to the mortar slurry for lightweight cellular concrete, it is possible to suppress the initial expansion of the mortar slurry due to the generation of hydrogen gas, and Good foamability can be exhibited without lowering the foaming efficiency of the mortar slurry. Furthermore, even at high temperatures, even when quick lime under different firing conditions or cement with different hardening rates are used, it is possible to produce a lightweight cellular concrete that is extremely effective industrially.

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

[Brief description of drawings]

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

Claims (1)

[Claims] 1. Aluminum powder, and 0.5 to 15 parts by weight of an organophosphate compound having a melting point of 30 ° C. or more and one or two acidic OH groups, based on 100 parts by weight of the aluminum powder, and nonion. 1 to 15 surfactants
A foaming agent composition for lightweight cellular concrete, characterized by containing 5 parts by weight of a solvent containing an alcoholic OH group and 5 to 70 parts by weight of a hydrocarbon solvent.