JPS6350374A - Manufacture of lightweight ceramic formed body - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a lightweight ceramic molded body suitable as a heat-insulating and fire-resistant material.

[Prior art] Inorganic foams, especially glass foams and calcium silicate molded bodies, contain independent or continuous fine pores and are lightweight, nonflammable,
Because it has excellent properties such as fire resistance, heat insulation, sound absorption, and workability, it is widely used as a noncombustible heat insulating material in building materials, such as ceiling panels, side walls, and partition walls, and also as a steam vibrator.

It is also used as a heat insulator for ducts, refrigerators, etc. Glass foam is made by mixing glass powder and blowing agent powder, firing the mixture, and incorporating gas generated by the blowing agent into the softened glass to reduce the weight. The glass powder used is one having a relatively low softening temperature, such as plate glass or pin glass.The blowing agent used is one that generates carbon dioxide, such as a carbonaceous substance or a carbonated substance.

Calcium silicate molded bodies are produced by subjecting calcareous substances and silicic materials to a hydrothermal reaction in an autoclave. In this case, there are two methods: curing a molded body in an autoclave and dehydrating and molding a slurry cured in an autoclave.

However, foamed glass has essentially low strength and is difficult to use as a self-supporting building material, and its use as a heat insulating material or sound absorbing material is limited.Furthermore, the finished raw material does not have self-supporting properties. Then, it is necessary to take the troublesome measure of packing this into a mold and performing low-temperature firing, and then removing the mold when loading it into a lehr. Moreover, it is therefore difficult to manufacture large-sized members. In addition, foam generation is unstable and it is very difficult to obtain a uniform foam.

In addition, calcium silicate molded bodies have low strength. Due to its lack of toughness, it is usually reinforced with reinforcing fibers. However, reinforcement with asbestos m-fibers is subject to legal regulation due to the risk of workers contracting diseases such as silicosis and lung cancer, and organic fibers also have drawbacks in terms of fire resistance. . Although reinforcement with glass fibers does not have the above-mentioned drawbacks, it cannot be said that it has overcome the drawback of lack of toughness, and problems such as corner defects in the product remain. Furthermore, since it is difficult to homogeneously mix any reinforcing fibers with calcium silicate hydrate, there is a limit to the proportion of reinforcing fibers that can be mixed into the molded body, and therefore the strength cannot exceed a certain limit.

Furthermore, since both the glass foam and the calcium silicate molded body contain many open pores as well as closed cells, the glass foam and the calcium silicate molded body may absorb water and deteriorate their heat insulation properties.

[Problems to be Solved by the Invention] The present invention was developed as a result of intensive research to solve the above-mentioned problems of inorganic foams such as glass foams and calcium silicate molded bodies. We have discovered that by fixing objects with molten glass, it is possible to produce lightweight, strong, non-combustible, and fire-resistant ceramic molded bodies.

Therefore, it is an object of the present invention to provide a ceramic molded body that is lightweight, has a certain degree of strength, is self-supporting, and has no corner chips. Another object of the present invention is to provide a method for economically producing the above-mentioned ceramic molded bodies useful as heat insulating materials and sound absorbing materials. A further object of the present invention is to provide a method for easily manufacturing a lightweight ceramic molded body that is tough, has a certain degree of strength without using fibers such as asbestos, and has homogeneity. .

[Means for Solving the Problems] The present invention involves dehydrating and molding a slurry consisting of 5 to 60 parts by weight of glass powder, 40 to 95 parts by weight of calcium silicate hydrate, and drying the slurry to form a slurry of the glass powder. This is a method for producing a lightweight ceramic molded body, which is characterized by firing at a temperature higher than the softening point and then cooling and solidifying it.

[Function] According to the present invention, a slurry consisting of glass powder, calcium silicate hydrate, and water is dehydrated and molded to produce a solid body,
This is fired at a temperature higher than the softening point of the glass powder to melt the glass powder, and the molten glass fixes and solidifies the calcium silicate hydrate to form a strong molded body.

According to the present invention, a slurry is first made of 5 to 60 fi (i parts) of glass powder, 40 to 95 parts by weight of silicate hydrate, and water, and then the slurry is dehydrated to form a molded body. is dried and fired at a temperature higher than the softening point of the glass powder.Then, the glass powder in the dehydrated molded body melts and solidifies, and when cooled and solidified, a lightweight ceramic molded body is obtained. It will be done.

The glass powder used in the present invention is not limited,
Any glassy substance can be used. In particular, glass powders such as plate glass and pin glass, which have a relatively low softening point and are readily available at low cost, are suitable.

It is also possible to use glaze frit, and it is also possible to use crushed natural glass and industrial waste glass. When using glass with a high softening point, compounds such as Na and Li can be added to lower the softening point.

Calcium silicate hydrate is a hydrothermal reaction product of a substance consisting of a calcareous substance, a silicic substance, and water.
Mix in a 1:1 ratio.

For this calcium silicate hydrate, xonotlite is most suitable, which is obtained by adding water in an amount of 7 to 20 times the weight of solid 1, mixing the mixture, and subjecting the mixture to a hydrothermal reaction in an autoclave at a temperature of about 200°C. It is preferable to add powdered glass, adjust the amount of water if necessary to make the mixture uniform, and then dehydrate and mold.

The dehydration molding method may be press molding, 2-extrusion molding, 8' molding, or the like. when molding.

In order to prevent molded products from losing their shape in subsequent processes,
Glass fiber and asbestos are added to the blended raw materials.

Reinforcing a-fibers such as organic fibers, inorganic arsenic materials such as water glass, polyvinyl alcohol, vinyl acetate emulsion, carboxymeglucoselose, starch aqueous solution, and organic compounds can be used as binders.

After dehydration molding, the mold is removed and dried. The drying method temperature is preferably 100 to 120°C, 1.a degree, but is not limited to this, and drying and firing can be performed in the same furnace. It can also be carried out in a separate furnace. Furthermore, it is also possible to perform drying and firing without demolding.

The present invention creates a strong molded body by fixing the silicate hydrate phase with the molten glass phase.1 The firing process according to the present invention involves raising the temperature of the solid body above the softening point of the powdered glass. need to rise.

The softening point of powdered glass is determined by the chemical composition of the glass, so the firing temperature varies depending on the powdered glass used and cannot be specified. death,
It is something that must be decided.

Furthermore, in the present invention, in order to fix the glass phase between the calcium silicate phases, it is necessary to melt the glass to an appropriate state, and the firing temperature or firing time must be appropriately selected.

If a glass with a high softening point is used, it is necessary to lower the firing temperature to tS, but if it exceeds 810°C, the hydrated silicate changes to wollastonite, and the volume of the molded body changes. Therefore, it is desirable to perform firing at a temperature below this temperature.

If glass with a low softening point is used, the firing temperature may be low, but on the other hand, the softening temperature of the lightweight ceramic molded article of the present invention will also be low, resulting in a decrease in fire resistance.

The amount of powdered glass used for fixing according to the present invention is set to 5% by weight for 11 small pieces because if it is small, the strength will not be sufficient and self-supporting properties will not be obtained. Furthermore, if the amount of powdered glass is too large, the bulk specific gravity becomes large, making it impossible to reduce the weight. The maximum amount of powdered glass was 60% by weight due to the reduced insulation effect. Therefore, the ratio of the powdered glass and calcium silicate hydrate is preferably such that 40 to 95% by weight of calcium silicate is mixed with 5 to 60% by weight of one glass powder.

Furthermore, in order to provide two colors, that is, when used as a building material, interior material, or exterior material, it is also possible to use an inorganic pigment or the like in combination with powdered glass to provide a desired color appearance.

The lightweight ceramic molded body manufactured by the manufacturing method of the present invention can be used as a building material, a building component, and as a heat insulating material.
It is also useful as a sound absorbing material.

In addition, the method for producing a lightweight ceramic molded body according to the present invention is as follows:
It is advantageous in that it can be applied to large products.

Next, the method for manufacturing a lightweight ceramic/customer molded article according to the present invention will be explained using a specific example, but the present invention is not limited to the first embodiment.

[Example] Materials used in Examples and Comparative Examples are shown below.

Kokei Calunium slurry Mix slaked lime and crystalline silica powder so that the molar ratio of CaO and 5ift is 1, add 4 times the weight of water to form a slurry, and allow to react at 90°C for 1 hour. After the slurry was gelatinized, water three times the weight of the slurry was added, and the mixture was reacted at 210° C. for 4 hours with stirring in an autoclave.

L25 Roku Mei glass powder is Toshiba solder glass powder (softening point 64
0°C).

[Examples 1 to 8] The above materials were blended in the proportions shown in Table 1, the uniform mixture was placed in a press mold, and a press pressure of 50 kg was applied.
f/cm', dried at a temperature of 120°C for 5 hours,
Thereafter, it was heated at a temperature of about 700°C for about 1 hour to produce a plate-shaped molded body.

In addition, the size of the prototype molded plate was 7115 in each example.
0 mm, width 100 mm, and thickness 12 mm.

[Comparative Example] Similar to the Example, the above materials were mixed in the proportions shown in Table 1,
A uniform mixture of this was put into a press mold and molded at a press pressure of 50 kgf/am'', and at a temperature of 120°C it was
This is a plate-shaped molded product manufactured by drying for a long time.

Molded objects manufactured in each example and comparative example P! , :J, The results of the experiment are further shown in Table 1.

[Effects of the Invention] The method for producing a lightweight ceramic molded body of the present invention provides, firstly, a heat insulating material having a certain degree of strength and self-supporting properties;
Second, it has become possible to manufacture lightweight ceramic molded bodies useful as sound absorbing materials.

Thirdly, it has a homogeneous structure and is tough.

Fourth, it is possible to provide a lightweight ceramic molded body that has a certain degree of strength without mFa reinforcement such as asbestos.
Firstly, it is possible to provide a method for easily producing a lightweight ceramic molded body with significantly improved strength and physical properties at low cost.Fifth, it is possible to provide a lightweight ceramic molded body with improved water absorption rate. Technical effects such as:

Patent applicant Mitsubishi Mining Cement Co., Ltd. Agent Patent attorney Hiroshi Kuramochi (one other person) Procedural amendment (voluntary) January 21, 1985? Date and time Commissioner Akio Kuroda1, Indication of the case, 1985 Patent Application No. 192732, 2゜Name of the invention, Process for producing lightweight ceramic molded bodies 3, Person making the amendmentRelationship with the case Applicant Tm Marunouchi, Chiyoda-ku, Tokyo- Chome 5-1 Name: Mitsubishi Mining and Cement Co., Ltd. Presenter Masaya Fujimura” 6 Agent Tm 707-7 Kojimachi Nagatani Mansion, 11-1 Ichibancho, Chiyoda-ku, Tokyo 102 Contents of amendment (1) Statement On page 2, lines 15 and 16, [silicic material] is corrected to [silicic material].

(2> Correct [Slow Cooling Furnace] to [Slow Cooling Furnace] on page 3, line 4 of the specification.

(3) Delete [Asbestos] on page 7, line 12 of the specification.

(4) In the eighth line from the bottom of page 10 of the specification, [the molar ratio is 1] is corrected to [the molar ratio is 1:1].

Claims (2)

[Claims] (1) A slurry consisting of 5 to 60 parts by weight of glass powder, 40 to 95 parts by weight of calcium silicate hydrate, and water is dehydrated, dried, fired at a temperature higher than the softening point of the glass powder, and then cooled. A method for producing a lightweight ceramic molded body characterized by solidification. (2) The method for producing a lightweight ceramic molded body according to claim 1, wherein the calcium silicate hydrate is a hydrothermal reaction product of a substance consisting of a calcareous substance, a silicate substance, and water.