JPH08301675A - Production of glazed cement product - Google Patents

Abstract

PURPOSE: To suppress a glaze trouble phenomenon such as glaze peeling and produce a glazed cement excellent in quality and performances. CONSTITUTION: The substrate treatment of the surface of a cement molding is carried out with a glaze having a lower melting point than that of a glaze used for forming a glaze layer. A mixture prepared by mixing an organic emulsion in a sliplike glaze is used as a glaze to form the glaze layer on the surface. The cement molding having the glaze layer is baked to form a glaze finish layer and the cement molding having the glaze finish layer is then cured and hardened to produce the glazed cement product having the glaze surface on the surface thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a glazed cement product, and more specifically, to a cement product such as a concrete panel used for the interior surface or exterior surface of a building, the surface of which is made of glass material. The present invention relates to a method for producing a glazed cement product having a glazed surface.

[0002]

2. Description of the Related Art Glazed cement products are glass products that have a glassy glaze surface, such as the surface of ceramics, on the surface of cement products such as concrete panels, and are much more beautiful and smooth than conventional cement products. It has a nice appearance. Further, it has the advantage that it is hard to get dirty and is not easily scratched, and it has come to be used as an interior finish surface or an exterior finish surface of various buildings.

To produce a glazed cement product, first,
Ordinary Portland cement is mixed with sand and other aggregates and water and other materials, and this is subjected to aging by a mold of a predetermined shape, then demolded, and dried to form a semi-dry cement compact. The surface of the cement molded body (bottom surface of the mold) is coated with a mud-like glaze such as boric acid frit as used in the manufacture of ceramics. This work is called glazed. As a specific operation for applying the glaze, a liquid glaze is applied to the surface of the cement molded product by using a spray gun or a roll used for coating or the like to form a glaze layer having a predetermined thickness.
After firing the cement molded body with this glaze layer formed,
When the cement molded product is cured and cured, a glazed cement product having the above-mentioned glassy glaze surface can be obtained.

[0004]

In the glazed cement product manufactured by such a method, by forming various patterns on the bottom surface of the mold, any pattern can be transferred to the glaze surface to further enhance the design. be able to. However, in the above conventional manufacturing method, cracks may occur on the glaze surface at around 700 ° C. due to the difference in thermal expansion coefficient between the glaze surface formed by melting the glaze and the cement molded body. When such cracks occur on the glaze surface, the glaze bald phenomenon in which the glaze surface is turned up by carbon dioxide gas (CO ₂ ) generated at around 800 ° C. due to the decomposition of water vapor and calcium carbonate (CaCO ₃ ) components by the water in the cement. The glaze defect phenomenon may occur.

In addition, when baking after forming the glaze layer, water in the glaze layer evaporates before the glaze melts at a temperature near 300 ° C., and cracks due to drying shrinkage of the glaze layer occur. There is. If such a crack occurs in the glaze layer, even if the glaze melts and a glaze surface is formed, the glaze does not stay in the crack occurrence portion and the glaze surface is not formed there.

Further, unless the cement compact is cured in a mold and demolded and then dried for a certain period of time (about 3 to 5 hours) to bring the cement compact into a semi-dried state, steam is generated from the cement compact during firing. May occur in a large amount to deteriorate the adhesion between the glaze surface and the surface of the cement molded body, and the glaze failure phenomenon as described above may occur. Therefore, there is a problem that it takes a long time to dry after removing the mold.

Therefore, an object of the present invention is to provide a method for producing a glaze cement excellent in quality performance by suppressing the occurrence of glaze defect phenomena such as glaze baldness in the above-mentioned method for producing a glazed cement product. is there. Another object of the present invention is to provide a method for producing a glazed cement product capable of suppressing the occurrence of cracks in the glaze layer due to evaporation of water in the glaze layer.

Yet another object of the present invention is to provide a method for producing a glazed cement product which can shorten the time until the glazed cement molded article is demolded.

[0009]

According to a first aspect of the present invention, there is provided a method for producing a glazed cement product, wherein a glaze layer is formed on the surface of the cement molded product, and the cement molded product having the glaze layer is fired to form a glaze finish layer. After forming, in the method of curing the cement molded article having this glaze finish layer to produce a glazed cement product having a glaze surface on the surface, in the glaze-like glaze to form a glaze layer organic to glaze-like glaze It is characterized by using a mixture of emulsions.

In the method for producing a glazed cement product according to a second aspect, a glaze layer is formed on the surface of the cement molded product, the cement molded product having the glaze layer is fired to form a glaze finishing layer, and then the glaze layer is formed. In the method of producing a glaze cement product having a glaze surface by curing and curing a cement molded article having a finishing layer, a glaze having a lower melting temperature than the glaze used for forming the glaze layer is used before forming the glaze layer. It is characterized in that the surface treatment is performed.

In the method for producing a glazed cement product according to a third aspect of the present invention, a glaze layer is formed on the surface of the cement molded product, the cement molded product having the glaze layer is fired to form a glaze finish layer, and then the glaze layer is formed. In the method of producing a glaze cement product having a glaze surface by curing and curing a cement molded article having a finishing layer, a glaze having a lower melting temperature than the glaze used for forming the glaze layer is used before forming the glaze layer. It is characterized in that a glaze layer is formed by using a mixture of sludge-shaped glaze mixed with an organic emulsion as a glaze.

A method for producing a glazed cement product according to a fourth aspect is the method according to the first or third aspect, wherein the organic emulsion comprises an acrylic resin emulsion. The method for producing a glazed cement product according to claim 5 is the method according to any one of claims 1, 3 and 4, wherein the mixing ratio of the organic emulsion is 2.5 to 15 weight relative to the sludge-like glaze. % Range.

[0013]

According to the method for producing a glazed cement product according to claim 1, a glaze layer is formed on the surface of a cement molded article by using a mixture of sludge-shaped glaze and an organic emulsion, and the cement molding having the glaze layer is provided. After the product is fired to form a glaze finish layer, the cement molded product having this glaze finish layer is cured and cured to produce a glazed cement product having a glaze surface.

Here, since the organic emulsion is mixed in the glaze-like glaze, even if the water in the glaze layer evaporates at around 300 ° C., the organic emulsion remains in the glaze layer and the strength of the glaze layer. Is higher and cracks are less likely to occur in the glaze layer. In the method for producing a glazed cement product according to claim 2, after the base treatment is performed using a glaze having a melting point lower than that of the glaze used for forming the glaze layer on the surface of the cement molded article,
A glaze layer is formed on the surface that has been subjected to the base treatment, the cement molded product having this glaze layer is baked to form a glaze finish layer, and then the cement molded product having this glaze finish layer is cured and cured to obtain a glaze surface. Manufacture glazed cement products with.

Here, since the base treatment is performed with a glaze having a lower melting temperature than that of the glaze used before forming the glaze layer, the adhesion between the glaze surface and the cement molded product is increased, and cracks are generated even if the coefficient of thermal expansion is different. It is difficult to do so, and the occurrence of glaze defects such as glaze baldness due to the generation of carbon dioxide and water vapor is suppressed. Further, even if steam is generated, glaze failure is unlikely to occur, so that a drying step in manufacturing a cement molded product can be omitted, and the time from demolding to glaze can be shortened.

In the method for producing a glazed cement product according to claim 3, after the ground treatment is performed using a glaze having a melting temperature lower than that of the glaze used for forming the glaze layer on the surface of the cement molded product,
A glaze layer is formed on the ground-treated surface by mixing an organic emulsion with a glaze-like glaze, and the cement molded article with this glaze layer is baked to form a glaze finish layer, and then this glaze finish A cement molded product having a layer is cured and cured to produce a glazed cement product having a glaze surface.

Here, before the glaze layer is formed, the glaze has a lower melting temperature than the glaze used for the base treatment, so that the adhesiveness between the glaze surface and the cement compact is high and cracks are generated even if the coefficient of thermal expansion is different. Even if carbon dioxide gas or water vapor is generated near 800 ° C., the glaze defect phenomenon such as glaze baldness is suppressed from occurring. Further, even if steam is generated, glaze failure is unlikely to occur, so that a drying step in manufacturing a cement molded product can be omitted, and the time from demolding to glaze can be shortened. Furthermore, since the organic emulsion is mixed in the glaze-like glaze, even if the water in the glaze layer evaporates at around 300 ° C, the organic emulsion remains in the glaze layer and the strength of the glaze layer becomes high. The layer is less likely to crack.

In the method for producing a glazed cement product according to a fourth aspect, a glaze obtained by mixing an organic emulsion containing an acrylic resin emulsion into a mud-like glaze is used. In the method for producing a glazed cement product according to claim 5, the mixing ratio of the organic emulsion is 2.
Since the amount is in the range of 5 to 15% by weight, it is possible to suppress the occurrence of the foaming phenomenon due to the mixing type and the generation of cracks due to the insufficient mixing.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a flowchart showing a manufacturing process of an embodiment of a method for manufacturing a glazed cement product according to the present invention. In FIG. 1, a glazed cement panel, which is a glazed cement product, includes a step of kneading cement, aggregate and water to obtain a cement material, a step of placing the cement material in a mold, and a semi-curing in the mold. , The step of pretreating the surface of the cement compact after demolding, the step of glazeing the surface of the cement compact that has been pretreated, the step of firing the glazed cement compact, and the rehydration of the cement compact after cooling. It consists of a curing process. In this ground treatment process, a glaze that has a lower melting temperature than the glaze used in the glaze process is used as the glaze, and in the glaze process, a mud-like glaze such as a frit or leaded frit is used for the glaze, such as an acrylic resin emulsion. The fact that an organic emulsion is mixed is a feature of the embodiment of the present invention.

Hereinafter, a method for manufacturing a glazed cement panel of the embodiment will be described in the order of steps. First, Portland cement, aggregate, water, and a high-performance water reducing agent are put in a mixer and well mixed to prepare a cement material such as mortar or concrete. As aggregate, shale aggregate, magnetic chamotte,
Mine firestones or the like which are normally used may be used. An appropriate admixture or admixture may be used depending on the properties such as strength and water resistance required for the glazed cement panel. Further, when reinforcing the glazed cement panel, a reinforcing material such as a reinforcing bar or a net may be embedded in the formwork in advance.

Subsequently, the obtained cement material is placed in a mold. After placing on the mold, the curing conditions are controlled and curing is performed for a predetermined time and a half. The curing time is preferably 4 to 12 hours in consideration of the moving time of water and productivity. This curing can be performed by warm air curing, natural curing, infrared heating curing, high frequency heating curing, or the like. After curing, demolding is performed, and the glaze that has a lower melting temperature than glazes such as raw glaze, boric acid-based frit glaze, and lead-based glaze, specifically 10 ° C to 100 ° C lower The surface is subjected to a surface treatment using a mud-like glaze. The coating amount in this case is about 50g / m ² ~150g / m ² is preferred. Then, the glaze, boric acid-based frit glaze, lead-based glaze, and other mud-like glaze mixed with an acrylic resin emulsion are used as glazes on the surface of the cement molded body that has been subjected to the base treatment.
Apply this. The acrylic resin emulsion at this time is an emulsion having a solid content of about 60% by weight. The mixing ratio of the glaze-like glaze and the acrylic resin emulsion is not particularly limited, but 2.5 to 15 parts by weight of the acrylic resin emulsion is preferable for 100 parts by weight of the glaze emulsion. If the amount of the acrylic resin emulsion is less than 2.5 parts by weight, the action of the resin component during evaporation of water in the glaze cannot be sufficiently exerted. If it exceeds 15 parts by weight, a bubbling phenomenon occurs and many pinholes are generated on the glaze surface. Further, the coating amount of the glaze is not particularly limited, but is generally 0.3 to ² kg / m ² , and is applied by brush coating, spray coating, flow coating or the like.

The glazed cement compact is fired in a firing furnace such as a roller hearth kiln. The firing conditions vary depending on the type of glaze, etc., but are within the range of 800 to 900 ° C.
Baking is performed for about an hour. During this firing, water in the glaze layer evaporates at around 300 ° C. and cracks are likely to occur in the glaze layer. However, since the acrylic resin is mixed in the glaze, the strength of the glaze layer before melting after the acrylic resin is hardened and water is removed is increased, and cracks at low temperatures are less likely to occur. It should be noted that the mixed acrylic resin is decomposed and vaporized when the temperature becomes higher than that, so that it does not remain on the glaze surface.

Further, during firing, water in the cement compact evaporates at around 800 ° C., or calcium carbonate is decomposed to generate carbon dioxide gas. However, by forming the glaze layer after the base treatment, the base layer 13 is formed between the surface of the cement molded body 12 and the glaze layer 11, as shown in FIG. Adhesion between the glaze layer and the cement molded product surface before melting is enhanced by the action of the molten underlayer, and the occurrence of cracks at around 800 ° C. is suppressed. Therefore, even if carbon dioxide is generated due to water vapor in the cement or thermal decomposition of calcium carbonate, glaze baldness and the like are less likely to occur. Therefore, when a cement molded product is obtained, a drying step after demolding is unnecessary, and the time required for it can be shortened.

The fired cement compact is immersed in water for about 30 to 60 minutes for rehydration, and then 50 to 50
It is cured at 60 ° C and 90 to 98% RH for about 3 days. Next, specific examples of the examples of the present invention will be described. First, 30.5% by weight of cement, 36.7% of expanded shale aggregate with a small particle size, and 32.8% of expanded shale aggregate with a large particle size were mixed. As the cement, ordinary Portland cement was used. 2% by weight of high-performance water reducing agent is added to this cement material.
50% by weight of water to the cement (W /
C ratio 50) and mixed well with a mixer.

The cement material thus obtained is
It was poured into a mold of 00 width × 300 length × 30 depth, half-cured at a curing temperature of 20 ° C. and a curing time of 12 hours, and demolded to prepare 60 cement compacts. A boric acid frit glaze having a melting temperature of about 510 to 610 ° C. is applied to the surface of the obtained cement molded product to form an underlayer, and then a boric acid frit glaze having a melting temperature of about 620 ° C. and an acrylic resin Ten glazes were applied to each of the six types of glazes having different mixing ratios, and firing was performed at 850 ° C. for about 1 hour. After firing, cool and soak in water for 30 minutes for rehydration treatment, 60 ℃
Cured under 98% RH for 3 days, and 10 glazed cement panels with 6 types of glaze with different mixing ratio of acrylic resin
It was manufactured individually.

Table 1 shows the mixing ratio of the sludge-like borate frit glaze and the acrylic resin emulsion during glaze application. Table 1 shows the presence / absence of glaze baldness when the mixing ratio of the acrylic resin emulsion to 100 parts by weight of the glaze-like glaze was changed. Here, ◯ indicates no glaze bald, and × indicates glaze bald.

[0027]

[Table 1]

As a result, as shown in Table 1, when the mixing ratio is less than 2.5%, glaze baldness occurs, and the mixing ratio is 1
It was found that even when the content exceeds 5% and becomes 20%, foaming occurs and pinholes are generated to cause glaze baldness.

[0029]

In the method for producing a glazed cement product according to the present invention, since the organic emulsion is mixed in the glaze-like glaze, even if the water in the glaze layer evaporates at around 300 ° C., the organic emulsion becomes It remains in the glaze layer, the strength of the glaze layer increases, and cracks are less likely to occur in the glaze layer.

Further, before the glaze layer is formed, the base treatment is performed with a glaze having a lower melting temperature than that of the glaze used for the glaze layer, so that the adhesiveness between the glaze surface and the cement molded article becomes high and cracks are generated even if the thermal expansion coefficient is different. It becomes difficult, and the occurrence of glaze defects such as glaze baldness due to the generation of carbon dioxide and water vapor is suppressed.
Also, since glaze trouble is unlikely to occur even if steam is generated,
It eliminates the need for a drying process when manufacturing cement molded products,
The time from demolding to glaze can be shortened.

[Brief description of drawings]

FIG. 1 is a flowchart showing a manufacturing process of an embodiment of a glazed cement product of the present invention.

FIG. 2 is a schematic sectional view of a glazed concrete panel before firing.

[Explanation of symbols]

 11 Glaze Layer 12 Cement Molded Body 13 Underlayer

Claims (5)

[Claims] 1. A glaze layer is formed on the surface of a cement molded article,
After forming a glaze finish layer by firing the cement molded article having this glaze layer, in the method of producing a glaze cement product having a glaze surface on the surface by curing and curing the cement molded article having this glaze finish layer, A method for producing a glazed cement product, wherein a glaze-like glaze mixed with an organic emulsion is used as the glaze for forming the glaze layer. 2. A glaze layer is formed on the surface of the cement molded article,
After forming a glaze finish layer by firing the cement molded article having this glaze layer, in the method of producing a glaze cement product having a glaze surface on the surface by curing and curing the cement molded article having this glaze finish layer, A method for producing a glazed cement product, which comprises performing a base treatment using a glaze having a melting temperature lower than that of the glaze used for forming the glaze layer before forming the glaze layer. 3. A glaze layer is formed on the surface of the cement molded article,
After forming a glaze finish layer by firing the cement molded article having this glaze layer, in the method of producing a glaze cement product having a glaze surface on the surface by curing and curing the cement molded article having this glaze finish layer, Prior to forming the glaze layer, the glaze layer having a lower melting temperature than the glaze used for forming the glaze layer is subjected to a base treatment, and then the glaze layer is mixed with an organic emulsion as a glaze-like glaze to form the glaze layer. A method for producing a glazed cement product, which comprises forming the glazed cement product. 4. The method for producing a glazed cement product according to claim 1, wherein the organic emulsion includes an acrylic resin emulsion. 5. The glazed cement product according to any one of claims 1, 3 and 4, wherein the mixing ratio of the organic emulsion is in the range of 2.5 to 15% by weight with respect to the mud-like glaze. Production method.