JP2538928B2 - Extruded building material composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a composition of an inorganic extrusion molding building material.

[Conventional technology]

Inorganic extruded building materials obtained by extrusion molding are widely prized as building materials centering on outer wall materials.The method of manufacturing them is to strengthen cement, slag, etc. hydraulic binders, asbestos, pulp, etc. A product in which a thickening agent such as fiber or methyl cellulose is mixed is extruded while being shaped by an extruder, and a product is obtained by steam curing under normal pressure or high temperature and high pressure. (JP-A-57-77058, JP-A-55-12460
5, see JP-A-57-3755) Among these conventional compositions, asbestos is an essential component in terms of the flow characteristics and shape retention of the mortar for extrusion.

However, since asbestos fibers are depleted in terms of resources and are harmful to the human body, development of a composition that can be extruded without containing asbestos fibers is desired.

Therefore, a composition for extrusion molding building materials (Japanese Patent Publication No. 59-30664) and a particle size of 50Å-0.5μ, which uses a siliceous granular material having a particle size of 50 μm or less, a water-soluble polymer and alkali-resistant glass fiber
m inorganic solid particles (A), solid particles (B) having a particle size of 0.5 to 100 μm, and a surface-active dispersant are used to adjust the composition so as to exactly fill the voids densely filled with the particles A and B ( Tokusho
60-59182) has been proposed.

However, the former composition has poor shape retention and it is difficult to produce a molded product having a complicated shape, and the latter composition inevitably has a water / solid content ratio of around 0.1. Has a high specific gravity and has a difficulty in workability such as cutting.

[Problems to be solved by the invention]

The present invention solves a problem that has not been achieved by the prior art, that is, it can be extruded without containing asbestos, and can manufacture a product having a complicated shape such as a hollow shape or a surface pattern, and can cut a molded product. It is an object of the present invention to provide an extruded building material composition having excellent processability such as.

[Means for solving problems]

That is, the present invention is an extrusion molding mixed material composed of at least a hydraulic binder, a reinforcing fiber and water,
Silica fume, pozzolanic siliceous dust such as diatomaceous earth, calcium carbonate, silica gel, fly ash or at least one ultrafine powder selected from finely ground products of cementitious substances and a set retarder Is a composition for extrusion molded building materials.

 Hereinafter, the details of the present invention will be described.

In the present invention, as the hydraulic binder, commercially available ordinary Portland cement, alumina cement or the like is used. These hydraulic binders generally have a weight average particle size of 20-30.
μm.

The type of reinforcing fiber is not specified as long as it is a reinforcing fiber, but fibers conventionally used for reinforcing cementitious materials can be used, and asbestos may not be used.
That is, inorganic fibers such as alkali resistant glass fibers and carbon fibers, and organic fibers such as various natural fibers and synthetic fibers can be used. The amount of the reinforcing fiber used is generally 0.5 to 5% by weight based on the total solid content, but it is not preferable to add 4% or more of organic fiber such as pulp and rayon when fire resistance is required. .

The ultrafine powder preferably has a weight average particle size of less than 3 μm, and particularly preferably less than 0.3 μm from the viewpoint of the flow characteristics of the kneaded product. A material having a weight average particle diameter of 3 μm or more is not an ultrafine powder and is inferior in the flow characteristics of the kneaded product and the shape retention of the green sheet after extrusion molding.

As ultra-fine powder, silicon, silicon-containing alloys, and silica fume by-produced when producing zirconia, siliceous dust having pozzolanic properties such as diatomaceous earth is particularly preferable, calcium carbonate, silica gel, fly ash or cementitious material. Finely pulverized products can also be used.

Further, the addition amount of the ultrafine powder is preferably 5 to 40% by weight of the total solid content, and if it is less than 5%, the effects of adding the ultrafine powder such as the fluidity of the kneaded product and the shape retention of the green sheet are hardly exhibited.
%, If added in a large amount, the thixotropy of the kneaded product becomes large and the flow characteristics in extrusion molding deteriorate.

It is more preferable that the ultrafine powder be wet with 20 to 150% by weight of water in advance with respect to the ultrafine powder (hereinafter 20 to 15%).
0% slurry). When the ultrafine powder is used in a dry state, it is advisable to increase the amount of the curing retarder added or shorten the time from kneading to extrusion molding. As the curing retarder, oxycarboxylic acids, sugar alcohols, saccharides, and inorganic retarders can be used, but magnesium silicate having no water-reducing property is preferable.

The amount of the curing retarder used is 0.2 to 5% by weight of the total solid content.
However, if the amount is too small, the effect is weak, and if the amount is too large, the curing time is too long and the strength development of the product becomes difficult. By limiting the amount of the curing retarder in this way, even if ultrafine powder is used in combination, it can be molded with a water / total solids ratio of 0.20 to 0.40, is excellent in workability such as cutting, and even when extruded into a complicated shape. It is possible to obtain a product having a complicated shape without causing problems.

When a thickener is used in the composition of the present invention, a water-soluble polymer such as methyl cellulose or polyvinyl alcohol can be used as the thickener. The amount used thereof is generally 0.1 to 2% by weight based on the total solid content. Molding water is preferably 20 to 40% with respect to the total solid content,
If it is less than 20%, it becomes difficult to make the matrix density of the product 2.0 or less, and the workability such as cutting of the obtained product is poor, and if it exceeds 40%, the strength of the obtained product, for example, the bending strength is lowered. The composition thus blended is extruded and, if necessary, primary cured at 40 to 80 ° C. under saturated vapor pressure to obtain the handling strength of the molded product. Then, if necessary, this is cured at high temperature and high pressure using an autoclave curing kiln. The saturated vapor pressure temperature at this time is preferably 110 to 200 ° C.

〔Example〕

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples.
The present invention is not limited to these.

Examples 1 to 3 and Comparative Examples 1 to 3 were carried out with the compositions and compounding ratios shown in Table 1.

The raw materials and extrusion molding equipment used in each example are as follows.

Each raw material was powdered according to Table 1 and mixed well with stirring, and then water, an ultrafine powder slurry, a curing retarder, etc. were added and kneaded. After passing this kneaded product, it was molded by an extruder. This molded body was subjected to primary curing for 6 hours under a saturated steam pressure of 60 ° C., and then subjected to autoclave curing at a saturated steam pressure temperature of 179 ° C., a holding time of 1 hour, and heating / cooling at 80 ° C./h.

 The results are shown in Table 2.

As a result, in Comparative Example 1, the molding water content was low and the bending strength was strong, but the absolute dry specific gravity was high and the workability was poor. In Comparative Example 2, since the curing retarder was not added, the curing speed was high and the molded product was I couldn't get it. In Comparative Example 3, since the ultrafine powder was not added, the predetermined flow characteristics were not obtained, and the molded body could not be obtained.

On the other hand, in Examples 1 to 3, it is possible to manufacture extrusion molding having a complicated shape that is excellent in workability and bending strength.

(Effects of the invention) By using the composition of the present invention, even without using asbestos fibers, excellent workability such as cutting, and even in a complicated shape, no sagging, etc., and as a building material It can be an extruded product having required strength.

The absolute dry specific gravity was obtained by placing the test body at this time in a 105 ° C. dryer for 48 hours and then determining the weight and volume after that.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an extrusion-molded article showing the shape of a die when it is molded by an extrusion molding apparatus in order to evaluate the composition of the present invention.

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Claims (1)

(57) [Claims] 1. A mixture material for extrusion molding comprising at least a hydraulic binder, a reinforcing fiber and water, wherein silica fume, diatomaceous earth or other pozzolanic silica dust, calcium carbonate, silica gel, An extruded building material composition comprising at least one ultrafine powder selected from fly ash or a finely pulverized product of a cementitious substance and a hardening retarder.