JPH0429631B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing lightweight cellular concrete (hereinafter abbreviated as ALC), which is produced by curing with high temperature and high pressure steam. More specifically, when foaming a mixture of silicic raw materials and calcareous raw materials by adding water and metal aluminum powder as a foaming agent, a new foaming agent regulator is added to produce ALC with adjusted pores. The present invention relates to a method for manufacturing. ALC is made by pulverizing silicic raw materials such as silica sand, silica stone, and various granulated slags, and calcareous raw materials such as lime and cement, adding water and a small amount of metallic aluminum powder, stirring, and then allowing it to stand still. Alternatively, air is mixed into the slurry without adding metal aluminum powder, the slurry is made to contain air bubbles, semi-plasticized, and then transferred to an autoclave and subjected to high-temperature, high-pressure steam curing. The ALC produced in this way consists of the main raw materials,
For example, in the case of silica stone, the grade of SiO ₂ and the type and amount of impurities, and in the case of lime, the particle size and reaction rate with water, etc., subtly affect the quality of the product, and the compressive strength and wet/dry shrinkage rate as building materials. It is well known that this has a significant effect on the performance, appearance, etc. of On the other hand, in the foaming process of raw material slurry, the properties of air bubbles that account for about 50% of the slurry volume and voids caused by water and the like that account for about 30% also affect the strength, physical properties, and appearance of the product. It is said that it is preferable that most of the bubbles and voids in this foaming process form a spherical shape with a diameter of 1 to 2 mm so as not to impair the mechanical strength and physical properties of the product. As the cell forming agent for ALC, a mixture of metal aluminum powder and a small amount of cell stabilizer added is most preferable and is widely used. Conventionally, the above-mentioned bubble stabilizers include gelatin and glue, which form a colloidal structure in the walls of the bubbles generated by gas generation to stabilize the bubbles, and stabilizers that lower the surface tension of the raw material mixed slurry and reduce the surface tension of the bubbles. Surfactants such as alkylbenzenesulfonates and alkylnaphthalenesulfonates have been put into practical use in order to improve the toughness of layers and coatings. However, the gelatin and glue described above are ineffective unless used in relatively large amounts, and are effective only in areas where the slurry has a high viscosity. Many have large bubble diameters. In addition, surfactants, on the other hand, are effective only in the region of low slurry viscosity, but when manufacturing regular products with a specific gravity of 0.5, they must be used in relatively large amounts, and if used in large amounts, the water in the raw material It has disadvantages such as inhibiting the sum reaction and preventing the homogeneous production of calcium silicate hydrate having high crystallinity. An object of the present invention is to provide a method for producing ALC with well-organized pores using a foam stabilizer that does not have the above-mentioned drawbacks. In order to achieve this objective, the inventors of the present application have conducted intensive research and found that one or both of morpholine, which is used as a solvent for industrial chemicals such as resins and waxes, and ethanolamine, which is known as a hardening accelerator for cement, and soap. If a very small amount of a mixture of oleic acid and/or an oleic acid derivative used as a raw material is applied to the raw material slurry together with a predetermined amount of metal aluminum powder, suitable bubble formation will be performed during the foaming process, and the bubbles will be It was discovered that this is extremely stable, and the method of the present invention was developed. That is, the method of the present invention involves adding approximately 0.05 to 0.10% by weight of metallic aluminum powder to a mixture of calcareous raw materials such as lime and cement and silicic raw materials such as silica stone, silica sand, and granulated slag. An additive prepared by adding one or both of morpholine and ethanolamine and one or both of oleic acid and oleic acid derivatives in a weight ratio of 1 to 4:1, based on 100 parts by weight of the total solid content of the raw material. After adding 0.005 to 0.05 parts by weight of 0.005 to 0.05 parts by weight, foaming, semi-plasticization, and autoclave curing are carried out according to conventional methods to produce ALC in which pores are arranged in an orderly manner. In the method of the present invention, ethanolamine as a foam stabilizer is not specified, but mono-,
Preferred examples of di- and tri-ethanolamine and oleic acid derivatives include oleic acid methyl ester, oleic propyl ester, oleic acid butyl ester, oleic acid allyl ester, and oleic acid glycerin ester. The reason why the additive is prepared at a ratio of 1 to 4 to 1 to 1 of morpholine and/or ethanolamine and oleic acid and/or oleic acid derivatives is because if the ratio of amine salt is higher than this, the raw material slurry will coagulate. This is because the amine salt ratio is lower than this, the ratio of oleic acid increases, and the hydrophobicity becomes too strong and the dispersion of the metal aluminum powder itself becomes difficult. This is to inhibit the The amount of additives to be added is 0.005 to 0.05% by weight as solids based on the total solid content of raw materials.
If the amount is less than this, the effect of the present invention will hardly be observed, and if the amount is added more than this, not only will the effect not be improved, but it will even disturb normal bubble formation. It is preferable to use this additive after diluting it with water in advance at a ratio of approximately 1:1 from the viewpoint of adding a very small amount to the raw material. According to the method of the present invention, not only is the compressive strength and other physical properties excellent, but also the pore shape of the semi-plasticized material is maintained for a long period of time, as shown in the examples. There is almost no volumetric shrinkage even when left standing, and therefore the ALC of the product
is obtained with uniform pores of about 1 to 2 mm in diameter,
A product with excellent appearance can also be obtained. Examples will be described below. Example: 6 parts by weight of powdered quicklime, 22 parts by weight of Portland cement, 32 parts by weight of silica powder, 0.05 parts by weight of aluminum powder, and 40 parts by weight of water, divided by the total amount of solid content. Morpholine or ethanolamine and oleic acid or its derivatives are mixed in a predetermined ratio (wt%), the mixture is diluted 1:1 with water, and a predetermined amount of the solid content is added and stirred to form a slurry, which is then foamed. , semi-plasticized and then autoclaved, following normal operations.
ALC was manufactured, and the presence or absence of shrinkage of semi-plastic concrete was observed, as well as the compressive strength (JIST5416) and appearance of the ALC product. The results are shown in the table. The appearance indicates the number of pores per square meter that were visually observed to be approximately five times larger than normal pores (1 to ² mm in diameter).

[Table] The compressive strength shown in the table is less than 40Kgf/ ^cm2 ;
The criteria for determining acceptability was whether or not the semi-plasticized product showed shrinkage after being left indoors for 5 hours, but in experiments where the blending ratio of additives was outside the scope of the present invention.
Nos. 1, 11, and 12, and Experiment Nos. 13 and 14, which had a small amount of addition, had weak strength and other properties were poor, but all others had sufficient strength, and the pores were especially adjusted to form an elliptical shape. Almost no large pores were observed. In Experiments No. 1 and Nos. 11 to 14, clear shrinkage was observed when the semi-plasticized materials were left to stand.

Claims (1)

[Claims] 1. A mixture of calcareous raw materials such as lime and cement, silicic raw materials such as silica stone, and metal aluminum powder as a foaming agent, total solid content 100 as the main raw materials.
Add 0.005 to 0.05 parts by weight of an additive prepared by mixing one or both of morpholine and ethanolamine and one or both of oleic acid and oleic acid derivatives in a weight ratio of 1 to 4:1 to each part by weight. 1. A method for producing ALC with controlled pores, characterized by using a raw material consisting of: