JPH0637044B2 - Method for producing inorganic extrudate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an inorganic extrusion-molded article, and more particularly, to a good surface property when an inorganic material mixed with synthetic resin particles is extrusion-molded and cured by curing. The present invention relates to a novel method capable of obtaining a molded product having.

<Prior art> A kneaded product obtained by mixing inorganic synthetic materials such as cement and gypsum with light-weight synthetic resin particles such as styrofoam fine particles is extruded and then cured by autoclave to obtain a cured molded article. It is known. The weight reduction of the molded body is achieved by mixing the synthetic resin particles, and the synthetic resin particles are melted by the high heat during autoclave curing and the inside of the molded body is made porous, so that the heat insulating property and the sound insulating property are improved. Be improved. Further, since the molten synthetic resin is adhered and impregnated on the inner surface of the closed cells inside the molded body, the adhesion with the base material is improved, the strength is enhanced, and the waterproof property is improved.

<Problems to be Solved by the Invention> Although the extruded product obtained by mixing the lightweight synthetic resin particles in this way exhibits generally satisfactory properties, it still has a problem in practice. there were. That is, generally, the molded body immediately after being discharged from the extruder is released from the molding pressure and expands. However, in particular, when synthetic resin particles having large compressive deformability such as foam are mixed,
What was compressed and made flat during molding is restored as a result of release from the molding pressure, and the surface of the molded body is raised to form an irregular uneven surface. In addition, even when synthetic resin particles such as solid beads that are relatively hard to compress and deform are used, a so-called springback phenomenon appears immediately around the beads immediately after discharge from the molding machine, and beads near the surface rise up on the surface. Then, an irregular uneven surface is similarly formed. As a result, as shown in FIG. 5, the surface of the molded body A has irregular irregularities and the synthetic resin particles B are scattered inside the molded body, but the surface layer C _{1 of the} base material C ₁ which is extremely thin near the surface is formed. And scattered as a relatively thick surface layer C ₂ . When the molded body is put into the autoclave in this state, the synthetic resin particles are melted by high heat and become porous, but in the process, the extremely thin surface layer C ₁ is destroyed due to the contraction of the synthetic resin particles. As a result, a crater-shaped concave portion D is formed, while the relatively thick surface layer C ₂ is cured as it is to form a convex portion E, resulting in a molded body having extremely poor surface smoothness. Surface treatment after obtaining such a molded body not only makes the process complicated and complicated, but also
There was a drawback that a large amount of mortar had to be applied with an unnecessarily large coating thickness in order to make the uneven uneven surface smooth. Further, it is difficult to eliminate the irregular asperity surface when the resin coating is applied, and the designability cannot be improved. Furthermore, the adhesiveness with these coating materials could not be expected so much.

<Means for Solving Problems> The present invention, which was devised to solve the above problems, is based on an inorganic material as a main component. A kneaded product prepared by mixing a large number of synthetic resin particles therein is prepared by an extruder. Then, the obtained molded body is put into an autoclave to cure and cure the inorganic material, and the synthetic resin particles are melted to form a large number of voids in the cured body as melting marks of the synthetic resin particles. A method for producing an inorganic extruded body, characterized by forming the voids present on the ground surface as concave portions on the surface of the cured body by grinding the surface of the cured body thus obtained to a predetermined thickness. Is.

<Detailed Description of the Invention> A kneaded product is prepared by mixing an inorganic material as a main component with synthetic resin particles.

Inorganic materials are hydraulic materials such as cement and gypsum, and siliceous and calcareous raw materials that react with calcium silicate hydrate to form the base material of the extruded product that is cured by subsequent autoclave curing. It is a raw material of eggplant.

Synthetic resin particles can be appropriately selected and used from synthetic resin foams such as polyethylene, polystyrene, polypropylene, acryl, vinyl, and the like, unfoamed products, solid beads, etc. It is preferable to use finely crushed polystyrene foam particles as waste.

If necessary, the kneaded product may further contain asbestos, synthetic fibers, carbon fibers, wood fibers, reinforcing fiber materials such as alkali-resistant glass fibers, molding aids such as methylcellulose, air entraining agents and the like. .

The kneaded product obtained by adding an appropriate amount of water to the above raw materials is put into an extruder and molded. When discharged from the extrusion molding machine, as a result of being released from the molding pressure, the synthetic resin particles cause the surface of the molded body to rise irregularly, resulting in an uneven surface.

Such shaped bodies are then placed in an autoclave. At this time, the inorganic material is hardened to form a molding base material, and the synthetic resin particles dispersed and mixed inside the base material are melted by the high heat, and the molding body having many spherical cavities is made porous. To do.

Then, the surface of the obtained cured molded product is ground to a predetermined thickness by an appropriate means such as a grinder, a sander, or a sandblast. That is, as shown in FIG. 1, the molded body 1 cured by curing in an autoclave is that shown in FIG. 5 (right side).
The surface is in a non-uniformly roughened state, but by grinding it to a virtual line XX, an extruded body according to the method of the present invention as shown in FIG. 2 can be obtained. .

The molded body 1 includes a base material 2 made of a cured inorganic material.
A large number of closed-cell pores 3 that are melting marks of synthetic resin particles are scattered therein. In addition, the surface of the base material 2 is made substantially flat by the above-mentioned grinding process, and the concave portion 4 is partially exposed on the surface. The concave portion 4 is formed by cutting off a part of the substantially spherical synthetic resin melting mark by grinding, and a large number of various large and small concave portions can be present on the surface of the base material, giving a novel design property. At the same time, when the mortar or paint is applied to the surface of the molded body, the anchoring effect on these coating materials can be improved and the adhesion strength can be increased.

A molded body 1'shown in FIG. 3 is obtained by the above-mentioned process, and a surface layer composition mainly composed of cement slurry is applied to the surface of the molded body 1 shown in FIG. 2 and then cured by natural curing or heat curing. Thus, the surface layer 5 having a smooth surface without irregularities is formed. Also in this case, the surface layer composition enters the concave portion 4 formed on the surface of the base material 2 to enhance the adhesion strength.

A urethane-based, acrylic-based, epoxy-based, or other suitable resin can be added to the surface layer composition, and the surface layer 5 thus formed by adding the resin also functions as a waterproof layer.
Further, it can be used as a decorative plate as it is by adding a pigment, a dye or the like to the surface layer composition for coloring,
Alternatively, if the surface layer is colored white, the subsequent coloring can be performed arbitrarily and easily.

In order to further enhance the adhesion strength with the coating material such as mortar or the surface layer composition applied to the surface of the molded body, a large number of recesses 4 are formed by surface grinding of the cured molded body, especially only the upper portion of the spherical synthetic resin melting trace. It is preferable to scrape off the surface to form a large number of recesses 4'having a shape as shown in FIG. Such a surface shape cannot be formed by the embossing process, and also provides extremely novel designability.

To this end, ultrafine vibrations such as ultrasonic waves or high frequencies are applied to the taper pipe portion of the extruder to cause the kneaded product in the pipe portion to vibrate. As a result, the kneaded product was densified, and at the same time, the synthetic resin particles, which had a larger particle size and were lighter than inorganic materials such as cement, floated upward inside the tapered pipe and were extruded from the die to obtain an arbitrary shape. The molded body is configured so that the density of the synthetic resin particles on the surface side is high. By subjecting the molded body thus obtained to autoclave curing and surface grinding in the same manner as described above, a large number of recesses 4 can be formed uniformly on the surface,
Moreover, by adjusting the amount of grinding, it is possible to relatively easily and efficiently form the recess 4'having the shape shown in FIG. Thus, designability, yield, and productivity are remarkably improved.

<Effects of the Invention> According to the present invention, it is possible to obtain a molded article having excellent surface properties even when a kneaded product obtained by mixing synthetic resin particles in an inorganic material is extrusion-molded, and the design and coating material can be obtained. It is possible to manufacture a building material for interior and exterior, which has excellent adhesion with.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing an extruded body obtained through an intermediate step of the method of the present invention, FIG. 2 is a sectional view schematically showing a final product obtained by the method of the present invention, and FIG. A cross-sectional view schematically showing an extrusion molded body obtained by another embodiment of the method of the invention, FIG. 4 is a cross-sectional view showing a preferable shape of a recess formed on the surface of the molded body substrate by the method of the invention, and FIG. It is sectional drawing which shows the surface texture of the extrusion molded body manufactured by the conventional method. Explanation of reference numerals 1 ... Molded body, 2 ... Substrate, 3 ... Independent cell hole, 4,
4 '... concave portion, 5 ... cement surface layer

Claims (4)

[Claims] 1. A kneaded material prepared by mixing a large number of synthetic resin particles into an inorganic material as a main component and charging the kneaded material into an extrusion molding machine to perform extrusion molding. The molded body thus obtained is then charged into an autoclave. By curing the inorganic material and curing the synthetic resin particles so that a large number of voids are present in the cured body as melting marks of the synthetic resin particles, and the surface of the thus obtained cured body is ground by a predetermined thickness. A method for producing an inorganic extrusion-molded product, characterized in that the voids present on the ground surface are formed as recesses on the surface of the cured product. 2. A surface layer composition comprising cement slurry as a main component is applied to the surface of the molded body obtained by the grinding, and this is then cured and cured to further form a surface layer having a smooth surface. The method for producing an inorganic extrusion-molded product according to claim 1. 3. A method for producing an inorganic extrusion-molded article according to claim 2, wherein a synthetic resin is added and mixed into the surface layer composition. 4. The synthetic resin particles are floated above the kneaded material by vibrating the kneaded material in the extruder to obtain a molded article having a high density of the synthetic resin particles on the surface side. The method for producing an inorganic extrusion-molded article according to claim 1 or 2.