JPH0193304A - Manufacture of light weight extrusion molded building material - Google Patents

Abstract

PURPOSE:To lighten an extrusion molded product by removing the air out of mortar, filling the mortar at the ratio of 5kg/cm<3> or more and the mixing a foaming agent therein, kneading and extruding the same out of a molding die. CONSTITUTION:Mortar constituted at least of a hydraulic bonding material, reinforced fibers and water is processed in a kneader and then a foaming agent is mixed therein after removing the air from the mortar and filling the mortar at the ratio of 5 kg/cm<3> or more, which is further kneaded and then extrusion molded by a molding die. The material can be extruded out of a molding die installed on the end of an extruder without changing the fluidity of the mortar in the kneader and the extruder by this process, and as forming is completed instantly after extrusion, a given shape can be manufactured easily.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing lightweight extruded building materials.

(Prior art and problems) Inorganic extrusion molded building materials obtained by extrusion molding are widely used as building materials mainly for exterior wall materials. A compound containing a hard binder, reinforcing fibers such as asbestos and pulp, and a thickener such as methylcellulose is extruded using an extruder while being shaped, and the product is obtained by steam curing at normal pressure or high temperature and pressure. %) Among these conventionally used raw materials,
In particular, asbestos was an essential component of extrusion mortar from the viewpoint of fluidity and shape retention. However, since asbestos is depleted as a resource and is harmful to the human body, it is desired to develop a composition that does not contain asbestos and can be extruded.

For this reason, extrusion-molded building material compositions (fF Publication No. 59-30664) using siliceous granular materials with a particle size of 50 μm or less, water-soluble polymers, and alkali-resistant glass fibers and inorganic solids with a particle size of 50 A to 0.5 μm have been developed. Particle (4) and particle size 0
．． Compositions etc. prepared by using solid particles of 5 to 100 μm and a surface active dispersant so that the gaps filled with particles A and B are just filled with grooves (% Publication No. 60-59182)
is proposed.

However, the former composition has poor shape retention and it is difficult to manufacture molded products with complex shapes, and the latter composition inevitably has a water/solids ratio of around 0.1. The resulting molded product had a high specific gravity and had difficulty in processing such as cutting.

In addition, regarding the weight reduction of extrusion-molded building materials, conventional methods include ■ Addition of lightweight aggregate to the matrix (Japanese Patent Application Laid-Open No. 49-103
923 Publication), ■ Addition of highly water-containing materials such as cement hydrate (Japanese Patent Publication No. 5B-6706, Japanese Patent Publication No. 59-32
No. 418, (1) Extrusion of pre-foamed mortar (Japanese Patent Application Laid-open No. 178478/1983), etc. have been proposed.

However, these methods have the following manufacturing problems.

■ Addition of lightweight aggregates to the matrix Not only is it difficult to control weight reduction because the lightweight aggregates break in the kneader and extruder, but the addition of lightweight aggregates reduces thixotropy and extrusion moldability. There were problems such as a decrease in

■ Addition of high water content materials such as cement hydrates When the pressure in the mixer and extruder increases, the water content is forced out and the water separates from the mortar, which may cause the mortar to become clogged in the extruder.

Further, there are problems such as the need to add a larger amount of plasticizer (for example, methylcellulose) than usual in order to ensure thixotropy.

(2) Extrusion of pre-foamed mortar It is difficult to obtain a homogeneous overall matrix due to the coalescence of the air bubbles in the extruder. Furthermore, when the material passes through a deaeration zone, air bubbles disappear, making it difficult to reduce the weight.

The present invention is a manufacturing method for reducing the weight of extrusion-molded building materials that solves the above problems.

(Means for Solving the Problems) The present invention provides an extrusion molding mortar composed of at least a hydraulic binder, reinforcing fibers, and water. This is a method for producing lightweight extrusion-molded building materials, which is characterized by mixing a foaming agent after filling, and extruding from a die after mixing.

The present invention will be explained in detail below.

As the hydraulic binder used in the present invention, commercially available ordinary Portland cement, alumina cement, etc. are used.

Further, if necessary, a powdered silicic acid raw material can be used, and in particular, when used in combination with Portland cement or the like, one having a molar ratio of CaO to 5in2 of 0.3 to 1.2 is preferable.

Further, as the reinforcing fiber, the type is not specified as long as it is a reinforcing fiber, but fibers that have been conventionally used for reinforcing cementitious materials can 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 reinforcing fiber used is generally 0.5 to 5% by weight based on the total solid content, but organic fibers,
For example, when fire resistance is required for pulp, rayon, etc., it is not preferable to add 4 or more.

Further, as the blowing agent, an evaporative blowing agent is preferable, and representative examples include aliphatic hydrocarbons (low-boiling components of Ca-C7, such as n-propane and n-pentane), chlorinated aliphatic hydrocarbons, etc. (methyl chloride, methylene dichloride, etc.),
Fluorinated aliphatic hydrocarbons (Freon 11. Freon 11
4 etc.) t- can be used. The amount used is 0.0
It is 1 to 0.1% by weight.

Furthermore, the molding moisture is 15% based on the total solid content.
~40% by weight is preferred. If it is less than 15 inches, not only will the mortar be easily clogged in the extruder, but there will also be problems such as generation of debris on the mortar surface during foaming.
If it is larger, shape retention after extrusion will be obtained.

It is preferable to add a plasticizer to the mortar in the present invention as a method of improving shape retention. As the plasticizer used, in addition to cellulose derivatives such as methylcellulose, organic additives such as polyvinyl alcohol and polyethylene oxide can be used. The amount used is O.1 to 2 iits based on the total solid content.

Moreover, a synthetic resin emulsion can be used as a plasticizing aid. Synthetic resin used
Synthetic resin emulsions such as polyester, styrene-butadiene, synthetic boxy, acrylic, vinyl acetate, ethylene-vinyl acetate, urethane, vinyl chloride, and vinylidene chloride are relatively stable even when cement is added. Preferably.

When used, one or more of these can be used, and the amount added is preferably 0.1 to 20% by weight based on the total solids of the extrusion molding composition. 0.5~ considering productivity, nonflammability, etc.
The content is preferably 5% by weight.

If it is added before the air is removed, gas will be generated in the degassing zone of the extruder and the gas will be degassed, making it impossible to incorporate air bubbles and making it impossible to reduce the weight.

Further, if the filling pressure of the mortar is lower than 5 Kq/-, not only the shape retention of the mortar after extrusion cannot be ensured but also the blowing agent cannot be mixed uniformly, which is not preferable.

The method of the present invention allows extrusion through a die attached to the tip of the extruder without changing the flow characteristics of the mortar in the mixer or extruder, and foaming ends instantly after extrusion, making it easy to obtain a predetermined shape. It becomes easier. The molded product thus obtained is, if necessary, subjected to primary curing at 40 to 80° C. under saturated steam pressure to obtain 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 110
~200°C is preferred.

(Examples) The present invention will be described below with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Examples 1-3 and Comparative Examples 1-3 ゛It was carried out using the composition and blending ratio shown in Table 1.

The raw materials and extrusion molding equipment used on each side were boiled as follows.

Cement: Union As for each raw material, powders such as cement, crushed Toyane silica, asbestos, acrylic fiber, and pulp fiber were thoroughly stirred and mixed according to Table 1, and then water and SBR latex were added and mixed. Finally, methylcellulose was added to this and thoroughly mixed and kneaded.

In Examples 1 to 3 and Comparative Example 2, these mortars were passed through a mixing machine, then air in the mortar was removed using an extruder, a blowing agent was added thereto, and the mortar was extruded from a die after mixing. On the other hand, in Comparative Example 1, a blowing agent was mixed in before removing air from the mortar, and in Comparative Example 3, extrusion molding was carried out without adding a blowing agent. .

This molded article was cured for 6 hours at 60 DEG C. under saturated steam pressure, and then autoclaved at a saturated steam pressure temperature of 145 DEG C. for a holding time of 5 hours and at a rate of 80 C/h each for increasing and decreasing the temperature. The results are shown in Table 2.

As a result, in Comparative Example 1, since the foaming agent was mixed before removing air from the mortar, it was foamed and degassed in the degassing zone, so air bubbles could not be introduced and weight reduction could not be achieved.

In Comparative Example 2, the mortar filling pressure was 39/d and 5Kql-
Because of this, not only is there a problem with the molding properties of the hollow top plate sagging, but there are also problems with the surface properties, such as blisters and cracks.

(Effects of the Invention) The manufacturing method of the present invention makes it possible to reduce the weight of an extrusion molded product while maintaining all moldability and surface properties regardless of the use of asbestos.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an extruded molded product, showing the shape of a die used in molding with an extrusion molding apparatus in order to evaluate various performances of the extrusion molded product according to the present invention. Patent applicant: Asahi Kasei Industries, Ltd. Figure 1

Claims (1)

[Claims] In an extrusion mortar composed of at least a hydraulic binder, reinforcing fibers, and water, the air in the mortar is removed and the mortar is filled to 5 kg/cm^3 or more, then a blowing agent is mixed in, and after kneading, a die is used. Method for producing lightweight extruded building materials characterized by extrusion