JP2001335381A - Production method of lightweight cellular material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently bake a lightweight cellular material. SOLUTION: Glass powder is mixed with an alkali solution, foaming agent and water, shaped, heated in the presence of water (steam curing), baked at 850-1,200 deg.C and expanded to obtain the objective lightweight cellular material having a unit volume mass of 0.15 to 0.5 kg/L.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a lightweight foam, and more particularly, to a lightweight aggregate for a building material board, a lightweight aggregate for a mortar, a soil conditioner, a heat insulating material for heat and cold insulation, an oil absorbing material, and the like. Manufacturing method of lightweight foam.

[0002]

2. Description of the Related Art Lightweight foams using natural glassy minerals such as perlite as raw materials have been reported in the past. For example, JP-B-36-6670 and JP-B-62
-12186. Further, a material using glass powder as a raw material is reported in Japanese Patent Publication No. 1-51451.

[0003] However, when a lightweight foam is produced by treating these natural vitreous minerals or glass powder as raw materials with an alkali such as sodium hydroxide, the alkali is water-soluble, and the moisture is evaporated. During the firing or firing, the alkali moves to the surface of the lightweight foam together with the moisture, so that the concentration of the alkali therein decreases. Therefore, when foaming, the inside remains powdery and a sufficient foam cannot be obtained,
There is also a problem that the obtained lightweight foam has a large unit volume mass.

[0004]

SUMMARY OF THE INVENTION The present inventor prevents the alkali from migrating to the surface of the lightweight foam by steam-curing the granulated material before firing, and allows the internal reaction to be sufficiently performed. As a result, the present inventors have found that a lightweight foam excellent in lightness can be efficiently produced, and have reached the present invention. In addition,
Steam curing refers to heating in the presence of water.

[0005]

Therefore, according to the present invention, a glass powder is mixed with an alkali solution, a foaming agent, and water, molded, steam-cured, and fired at 850 to 1200 ° C.
A method for producing a lightweight foam, which comprises expanding to produce a lightweight foam having a unit volume mass of 0.15 to 0.5 kg / L. Further, there is provided the method for producing a lightweight foam according to the above, wherein steam curing is performed at 80 to 300 ° C. for 10 seconds or more. The method for producing a lightweight foam according to the above-mentioned, wherein the molded article is covered with an anti-fusing agent at least once at any time after molding, after steam curing, or during firing. Further, it is the above-mentioned method for producing a lightweight foam, wherein the glass powder is expanded pearlite fine powder. Further, there is provided the method for producing a lightweight foam according to the above, wherein the alkaline solution is caustic soda. Further, there is provided the above-described method for producing a lightweight foam, wherein the anti-fusing agent is a high-melting substance such as kaolin or alumina. Further, there is provided the above-mentioned method for producing a lightweight foam, wherein iron oxide (trivalent) is added as a foaming aid.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The glass powder used as a raw material in the present invention is not limited, but expanded pearlite fine powder is particularly preferably used. The expanded pearlite fine powder is obtained by crushing the expanded pearlite powder, and the particle size is 1 μm.
m to 1 mm. Expanded pearlite powder that does not break may be used, but in this case, bubbles inside the foam shrink during firing, and a sufficiently lightweight foam cannot be obtained. The steam curing temperature is preferably from 80 to 300 ° C., and at a temperature of 80 ° C. or less, the reaction becomes slow, and there is no effect of the steam curing.
Above ℃, the cost increases. As a method of steam curing, besides the method described below, heating in a closed container or curing with the steam of the raw material itself in a semi-closed container may be used.

In the present invention, the expanded pearlite fine powder is mixed with an alkaline solution such as caustic soda, a foaming agent such as silicon carbide, and a foaming assistant such as iron oxide (trivalent).
Molded to about 5 mm, put it in a steamer and steam cured, then baked at 850 to 1200 ° C. and expanded to obtain a lightweight foam, but after molding, after steam curing or during firing At least one time, the molded article is dusted with a high melting substance such as kaolin or alumina as an anti-fusing agent. If the firing temperature is 850 ° C. or lower, a sufficiently lightweight foam cannot be obtained. On the other hand, at 1200 ° C. or higher, the cost increases.

[0008]

EXAMPLE 1 250 g of fine powder obtained by crushing expanded perlite was mixed with 100 ml of a sodium hydroxide solution (concentration: 20%), 2.5 g of silicon carbide as a foaming agent, and 2.5 g of iron oxide (trivalent) as a foaming aid. , Molded into a diameter of 6.5 mm, steam cured at 110 ° C. for 1 minute, and then baked at 1000 ° C. in an electric furnace.
The foam was expanded to obtain a lightweight foam. When the unit volume mass of the obtained lightweight foam was measured, it was 0.25 kg / L.

Example 2 2 kg of a caustic soda solution (concentration: 20%), 5 kg of fine powder obtained by crushing expanded perlite, 50 g of silicon carbide as a foaming agent,
Mix with 50 g of iron oxide (trivalent) as a foaming aid,
mm, steam cured at 300 ° C. for 30 seconds, and then dried. Then, 1 kg of kaolin is used as an anti-fusing material.
At the same time, it was fired at 1050 ° C. in a firing furnace and expanded to obtain a lightweight foam. When the unit volume mass of the obtained lightweight foam was measured, it was 0.23 kg / L.

Comparative Example 1 250 g of fine powder obtained by crushing expanded perlite was mixed with 100 ml of a caustic soda solution (20% concentration), 2.5 g of silicon carbide as a foaming agent, and 2.5 g of iron oxide (trivalent) as a foaming aid. Formed to 6.5mm in diameter, 110 ° C for 1 minute,
After drying in a drier, firing at 1000 ° C. and expansion were performed to obtain a lightweight foam. When the unit volume mass of the obtained lightweight foam was measured, it was 0.32 kg / L.

Comparative Example 2 250 g of fine powder obtained by crushing expanded perlite was mixed with 100 ml of a caustic soda solution (20% concentration), 2.5 g of silicon carbide as a foaming agent, and 2.5 g of iron oxide (trivalent) as a foaming aid. Formed to 6.5 mm in diameter, 1000 without drying
C. and swelled to obtain a lightweight foam. When the unit volume mass of the obtained lightweight foam was measured, it was 0.31 kg /
L.

[0012]

According to the present invention, a lightweight foam is efficiently produced.

Claims (7)

[Claims] 1. A glass powder is mixed with an alkali solution, a foaming agent, and water, molded, heated (steam-cured) in the presence of water, fired at 850 ° C. to 1200 ° C., expanded, and expanded to a unit volume. A method for producing a lightweight foam, comprising producing a lightweight foam having a mass of 0.15 to 0.5 kg / L. 2. The method for producing a lightweight foam according to claim 1, wherein steam curing is performed at 80 to 300 ° C. for 10 seconds or more. 3. The method for producing a lightweight foam according to claim 1, wherein the molded article is covered with an anti-fusing agent at least once after molding, after steam curing, or during firing. . 4. The method according to claim 1, wherein the glass powder is expanded perlite fine powder. 5. The method according to claim 1, wherein the alkaline solution is caustic soda.
A method for producing the lightweight foam according to the above. 6. The method for producing a lightweight foam according to claim 3, wherein the anti-fusing agent is a high-melting substance such as kaolin or alumina. 7. The method for producing a lightweight foam according to claim 1, wherein iron oxide (trivalent) is added as a foaming aid.