JPS58151386A - Glazed cement baked body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention relates to a glazed cement fired body, and more specifically,
A glazed cement fired body reinforced with metal wire, characterized in that an inorganic material that reversibly expands and contracts below the melting temperature of the glaze is used as at least part of the aggregate to prevent cracks during firing. It is related to.

Conventionally, glazed cement products reinforced with metal wires are well known (see Japanese Patent Application No. 55-60396), and glazed cement products are usually made from a raw material composition consisting of cement and various additives and fillers, and metals. It is obtained by molding the metal wires by casting or extrusion to form a molded body with the metal wires embedded inside, which is then glazed, fired, and then subjected to rewatering treatment.

However, conventional glazed cement products reinforced with metal wires are not always satisfactory, as cracks often occur in any of the above molded products when firing the molded products obtained by pour molding or extrusion molding. It's not possible.

In view of these circumstances, the inventors of the present invention have conducted extensive research in order to obtain a glazed cement fired product that does not cause cracks during firing, and have found that when cement products are fired with metal wires embedded, the expansion coefficient and the Cracks occur due to an inappropriate balance between the bonding force of the mortar and the strength of the mortar itself.On the other hand, certain inorganic substances, such as silica-1-zirconia and aluminum phosphate, expand when heated at temperatures below the melting temperature of the glaze. However, they focused on the fact that there is a reversible phenomenon of shrinkage when cooled, and discovered that if cement contains a predetermined amount of the inorganic substance as an aggregate, the above-mentioned balance could be brought about and the object of the present invention could be achieved. The present invention was completed based on the findings. In particular, silica as the inorganic substance is added at 50% by weight per 100 parts by weight of cement.
It was found that those containing ~150 parts by weight were most effective in preventing the occurrence of cracks.

That is, the present invention is characterized in that at least part of the aggregate contains an inorganic substance that reversibly expands and contracts below the melting temperature of the glaze, and in particular contains 950 to 150 parts by weight of silica per 100 parts by weight of cement. The present invention provides a glazed cement fired body reinforced with metal wire.

The cement used in the present invention can be arbitrarily selected from commonly used cements such as Portland cement, alumina cement, blast furnace slag cement, and mixed cement.

In the present invention, other inorganic substances capable of reversibly expanding and contracting used as at least a part of the aggregate include silica, zirconia, aluminum phosphate, etc. Any inorganic material can be used as long as it is an inorganic material that expands when heated to a predetermined temperature below the melting temperature and contracts when cooled. A suitable material is one that has approximately the same thermal expansion as the metal wire used in combination and has the particle size of an aggregate. Among these materials, the most common is silica sand, which is mainly composed of silica. It is.

Such inorganic substances are contained in an amount of 50% per 100 parts by weight of cement.
It is necessary to mix in a range of 150 parts by weight. If this amount is less than 50 parts by weight, the desired effect of the present invention will not be achieved, and if it exceeds 150 parts by weight, the strength of the obtained fired product will decrease.

Taking silica as an example, the α-Jβ type crystal dislocation point is 573°C, while the firing temperature is usually 650°C.
~900°C, so during firing the α-type to β-type
Crystal dislocation occurs in the mold and expands. Therefore, by incorporating silica into cement as an aggregate, it alleviates the shrinkage of mortar during firing, and stabilizes the expansion rate, the bonding force between metal wire and mortar, and the strength of the mortar itself. Therefore, no cracks occur in the obtained fired body. Further, a suitable particle size of the silica used in the present invention is about 100 μm to 2 trm.

In the present invention, additives and other fillers commonly used in raw material compositions, such as thickeners and inorganic fibers, can be used, and if desired, for example, water reducing agents, curing accelerators, curing Retarders, colorants, etc. can also be used.

Thickeners include methylcellulose, ethylcellulose,
Carboxymethyl cellulose, polyoxy7ethylene oxide, and polyvinyl alcohol are used, but methyl cellulose is particularly preferred. The thickener is preferably used in an amount of 1 to 3 parts by weight per 100 parts by weight of cement. If the amount is less than this amount, the plasticity will be insufficient, and if it is more than this amount, expansion or sagging will occur after extrusion, which is unsuitable especially in extrusion molding.

Next, as the inorganic fiber, inorganic fibers commonly used as reinforcing optical fibers such as asbestos, carbon fiber, and glass fiber can be used. This material imparts appropriate lubricity to the raw material composition, and plays the role of facilitating extrusion, particularly in extrusion molding, and suppressing sagging after extrusion. The amount of inorganic fiber used varies depending on the molding method, but in extrusion molding, it is preferably used at a ratio of 4 to 6 parts by weight per 100 parts by weight of cement. If the amount is less than this amount, sagging will occur after extrusion molding, and if it is more than this amount, the composition will become too hard and extrusion will not be carried out smoothly.

The raw material composition used in the present invention is prepared by adding water to a mixture of the above-mentioned components and thoroughly kneading the mixture. The amount of water depends on the additives used in combination, but is preferably in the range of 25 to 40 parts by weight per 100 parts by weight of cement. If it exceeds this amount, it will cause sauce, which is not preferable.

Next, in the present invention, the metal wire embedded in the fired cement body for reinforcement is iron wire, stainless steel wire, galvanized iron wire, or other corrosion-resistant metal wire with a diameter of 0.5 to 3111.
111 is preferably used. Although a commercially available metal wire may be used as it is, it is advantageous to use the metal wire after surface roughening treatment in order to improve its adhesion to cement. This surface roughening treatment may be carried out by chemical treatment to corrode the surface, or it may cause scratches or scratches on the surface.
Physical means such as spirals, protrusions, etc. may also be used.

In order to obtain the metal wire-reinforced glazed cement fired body of the present invention, the raw material composition and the metal wire are molded by a method such as pouring, pressing, or extrusion, and the molding is performed such that the metal wire is embedded inside. The method is to form a body, then glaze it, fire it, and then rewater it. in this case,
It is preferable to form the molded body by extrusion molding, and this extrusion molding is carried out by simultaneously extruding the metal wire and the raw material composition using, for example, a continuous extrusion molding apparatus having the structure shown in FIG.

That is, this molding device is composed of two extruders 1 and 1', a Y-shaped press-fit tube 2, and a molding die 3.
' are each equipped with a supply screw, a cutter vacuum chamber, and a delivery screw. The raw material composition is
It is simultaneously supplied from the supply ports of two extruders, fed by a supply screw, compressed and cut into chips by a cutter, enters a vacuum chamber, and falls while being degassed. The fallen raw materials are fed by a delivery screw and merge into the Y-shaped press-fit tube 2, where they are gradually compressed and compacted, and the metal wire B inserted from the branch of the Y-shaped press-fit tube 2 is pinched at the tip of the die. The molded product C is then extruded into a die 3 to obtain a cement molded product C in which metal wires are embedded.

The extrusion pressure at this time depends on the composition of the raw materials, the shape of the die, and the capacity of the extruder, and is not necessarily constant, but it is usually 5.
~ I 00 K4 f /cr/l.

The molded body thus obtained is then glazed. As the glaze, for example, a base consisting of glass powder and frit, to which commonly used auxiliary agents such as zinc white and zircon are added, and further, if desired, an inorganic pigment can be used can be used. This glaze is applied to the surface of the cement molded body by any method such as spray painting, dipping, or screening.

The cement molded body thus glazed is then fired. The firing temperature and firing time at this time depend on the type of metal wire and glaze, but are usually selected at a temperature in the range of 650 to 900°C for a time of 5 to 180 minutes.

This fired product then needs to be rewatered.

This rewatering can be done by either underwater curing or steam curing.
In the case of underwater curing, the temperature is immersed in water for several days to several tens of days at room temperature, and in the case of steam curing, the temperature is 40 to 60°C.
This can be done for several hours to several days, or by holding it in an autoclave for several hours under pressure.

The glazed cement fired body reinforced with metal wires of the present invention maintains the strength of the metal wire-reinforced cement itself, has excellent surface strength and durability, and has no cracks and a beautiful surface. Suitable as a building material and Efsteria material. It is especially suitable for use in areas that come into contact with water.

Next, the present invention will be explained in more detail with reference to Examples.

Example Ordinary Portland cement [manufactured by Onoda Cement ■] 10
0 parts by weight, No. 6 silica sand [manufactured by Katsuno Ceramics Raw Materials, particle size 250μ]
m-500pm) 50 to 150 parts by weight, asbestos (Australian commercial product 56D-20) 5 parts by weight, methylcellulose [manufactured by Shin-Etsu Chemical Co., Ltd., Metrose 90SH4]
000] 2.4 parts by weight and 32 to 39 parts by weight of water are mixed,
After thorough kneading, an extrusion molding machine as shown in Figure 1 [
Made by Miyazaki Iron Works, MV-FM improved type] using 2 units, diameter 2
It is co-extruded with 4 rust-free hard steel wires or annealed wires or galvanized ordinary iron wires of RAN, and the cross section shown in Fig. 2 (dimensions 12 x 25 non, hollow part 4 x 9
A long molded body having the following properties (wn) was manufactured.

This molded product was left covered with a damp cloth for one day, and then cured at room temperature for another one day, and then cut into a length of about 15 crn.

Next, a glaze consisting of 70 parts by weight of glass powder, 30 parts by weight of frit, 3 parts by weight of zinc white, 2 parts by weight of zircon, and 5 parts by weight of black pigment was applied to the surface of this molded body, and it was placed in an electric furnace and heated to 850 parts by weight. C. for 20 minutes. As a result of this firing, a beautiful black glassy film with no water permeability was formed on the surface of the cement compact.

After rehydrating this fired product by immersing it in water at 20°C for 3 weeks, it was placed in a constant temperature and humidity bath (20°C, 95% R,
H,) for 3 days.

Regarding the glazed cement fired body obtained in this way,
The presence or absence of cracks was examined. The results are shown in Table 1 along with the mixing ratio of silica sand and water and the type of metal wire.

The test was conducted twice under the same conditions, and crack generation was determined according to the following criteria.

Judgment criteria for crack occurrence: ○: No cracks occurred ×: Cracks occurred
A glazed cement fired body was obtained in exactly the same manner as in the example except that crushed sanitary ware, particle size of 590 μm or less was used, and the presence or absence of cracks was examined on this body. The results are shown in Table 2 along with the mixing ratio of Shelben and water and the type of metal wire.

The test was conducted twice under the same conditions, and the determination of crack occurrence was made according to the same criteria as in the Examples.

Table 2

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an example of a continuous extrusion molding apparatus for obtaining the glazed cement fired body of the present invention, and FIG. 2 is an explanatory diagram of an elongated molded body obtained by the continuous extrusion molding apparatus in Examples and Comparative Examples. FIG. In Fig. 1, numerals 1 and 1' are extruders, 2 is a Y-shaped press-fit tube, 3 is a molding die, A is a raw material composition, B is a metal wire, and C
In FIG. 2, reference numeral 4 indicates a through hole, and 5 indicates a metal wire. Patent applicant: Director of the Agency of Industrial Science and Technology and one other agent: Akira Agata

Claims (1)

[Scope of Claims] 1. A glazed cement fired body reinforced with metal wire, characterized in that an inorganic substance that reversibly expands and contracts below the melting temperature of the glaze is used as at least a part of the aggregate. 2 As an inorganic substance, 100 parts by weight of cement, 50~
A glazed cement fired body reinforced with metal wire according to claim 1, characterized in that 150 parts by weight of silica is used. 3. A glazed cement fired body reinforced with metal wires according to claim 2, characterized in that silica sand is used as the silica.