JPS6212682A - Manufacture of glazed cement product - 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] [Industrial application field] The present invention relates to a method for manufacturing glazed cement products.

In particular, the present invention relates to a method for manufacturing glazed cement products that can easily and inexpensively manufacture high-strength glazed cement products by applying a pour molding method or a spray molding method.

[Prior Art] Conventionally, when a cement product requires surface finishing, it has generally been painted with an organic paint or sprayed with a non-Jj1 or organic spray material.

However, there are 4 organic paints! ! Organic materials used in sprayed materials have problems with weather resistance, abrasion resistance, or chemical resistance, and inorganic materials may cause cracks to form as the material shrinks, causing the quality of cement products to deteriorate over the course of a year. There is also the problem that the cosmetic surface deteriorates and the beauty of the product is impaired.

In order to solve these problems, glazing has been proposed as a surface finishing method for cement products.

Therefore, as a manufacturing method for glazed cement products,
A method of applying a phosphoric acid-based frit glaze and then firing at a temperature lower than 650°C (“Glazed Concrete J E,
Tauber.

D. N. Crook & M. J. Murray
Hr Architectural Technology” Yang, 238. June 1971 issue, 157
(~161 pages) (1) After preliminary hydration hardening of the cement hardened material obtained by pressure dehydration molding, a normal glaze having a melting point of 650 to 1000°C is applied. The firing method (Special Publication No. 56-48464) is
Previously proposed.

[Problems to be Solved by the Invention] However, among the conventional methods for manufacturing glazed cement products in (1) and (2) above, method (2) uses a phosphoric acid-based glaze, which is difficult to solve compared to commonly used glazes. Not only was it inferior in weather resistance, abrasion resistance, and chemical resistance, but it was also very expensive, and the finish of the product was also poor, making it impractical.

In the method (2), the reason why a glaze having the following drawbacks is used is that the hardened cement body to which the glaze is applied is obtained by casting.

That is, the cement hardened body obtained by pour molding is
Fine bubbles remain in the cured product, the structure is coarse and dense, and the mechanical strength is weak, so if heated at a temperature exceeding 650°C,
Ca(
Cracks occur due to internal stress caused by decomposition and contraction of OH)2, expansion stress of microbubbles in the hardened body, and expansion stress due to vaporization of cement hydration water, resulting in a decrease in strength.
In this method, a phosphoric acid-based glaze that can be fired at a low temperature lower than 650°C is used.

On the other hand, by applying pressure dehydration molding as in method ① above, it is possible to prevent the remaining of substances that cause the formation of fine air bubbles in the resulting hardened cement product. The structure becomes denser and mechanical strength is increased. Therefore, in method (2), high temperature firing of 650°C or higher is possible, and ordinary glazes can be used.

By the way, the greatest advantage of cement materials is that they have a large degree of freedom in shaping. Common methods for molding cement materials include pour molding, pressure dehydration, extrusion, papermaking, and injection molding, each of which has its own advantages and disadvantages. Among these, the pour molding method: ■ does not require complicated molding equipment, ■ does not require any skill in molding and can be easily performed by anyone, ■ has a large degree of freedom regarding the external shape, ■
It has many advantages such as being easy to combine with other parts, and is the basic method for forming cement parts.

Even in the production of glazed cement products, by making the pour molding method possible, all other molding methods can be applied. The method was not industrially advantageous.

[Means for Solving the Problems] The present invention solves the above-mentioned conventional problems by mixing specific amounts of a heat-resistant short fiber material and a hardening accelerator into cement mortar.

The first method of the present invention is to pour and mold a cement mortar containing 100 parts by weight of cement, 1 to 20 parts by weight of a heat-resistant short fiber material, 10 to 30 parts by weight of a hardening accelerator, and 50 to 500 parts by weight of aggregate. After applying a glaze to the surface of the obtained cement molded body, it is fired at a temperature of 650-1000°C,
Next, it is cured.

In the second method of the present invention, a cement mortar containing 100 parts by weight of cement, 10 to 30 parts by weight of a hardening accelerator, and 50 to 200 parts by weight of aggregate is mixed with a heat-resistant short fiber material having a solid content ratio of 1 to 10 parts by weight. After spray molding to a fiber content of parts by weight and applying a glaze to the surface of the obtained cement molding,
It is fired at a temperature of 650 to 1000°C and then cured.

The present invention will be explained in detail below.

First, the production of a molded body in the first method of the present invention will be explained.

In the first method of the present invention, 100 parts by weight of cement, 1 to 20 parts by weight of heat-resistant short fiber material, and 10 to 20 parts by weight of hardening accelerator.
A molded body is produced by pouring and molding a cement mortar which is made by adding 30 to 50 parts by weight of water and thoroughly kneading 30 parts by weight and 50 to 500 parts by weight of aggregate as essential components.

Heat-resistant short fiber materials improve the strength of molded bodies and fired products, and disperse internal stress during firing.
If it is too small, the effect will be low, and if it is too large, the moldability will be poor. A particularly preferable amount of the heat-resistant short fiber material to be mixed is about 2 to 15 parts by weight.

The curing accelerator not only accelerates the curing of the molded body, but also improves the strength of the molded body and its fired product by acting alone and in synergy with the heat-resistant short am material. Therefore, if the amount mixed is too small, the strength improving effect will be low, and if it is too large, it will be difficult to mold.

: Casting of cement mortar in the method of JSl can be carried out under commonly used molding conditions. The obtained molded product preferably has a hardening temperature of 100 to 60
After drying by heating at 0°C, it is subjected to the first glazing process.

The molding method in the second method of the present invention includes cement 10
0 parts by weight, 10 to 30 parts by weight of hardening accelerator, and 50 to 30 parts by weight of aggregate.
A cement mortar made by kneading 200 parts by weight with 30 to 50 parts by weight of water is mixed with heat-resistant short fiber material in a solid content ratio of 1.
- It is spray molded to a TA fiber content of 10 parts by weight, preferably 2 to 8 parts by weight. In this method as well, the effects of the curing accelerator and the heat-resistant short fiber material are the same as in the case of the first casting method, and the molding conditions for spray molding are appropriately determined within the range normally employed.

Note that the raw material cement for the cement mortar in the first and second methods can be arbitrarily selected from hydraulic substances in the broad sense generally referred to as cement, such as Portland cement, alumina cement, and mixed cement. , ordinary Portland cement is preferred. As the aggregate, stable materials that do not undergo rapid expansion or contraction during the firing process, such as porcelain chamotte or andesite, are suitable.

Hardening accelerator refers to a material that has the property of rapidly hardening cement gel, and its components can be arbitrarily selected depending on the type of raw cement, but typical examples include CaO, A203 , Denka QT, which is a mixture of CaSO4, and Denka ES, which is a molten mixture thereof (
In the present invention, the curing time can be adjusted by mixing and using a reaction inhibitor in the cement mortar, if necessary.

In addition, as a heat-resistant short fiber material, aOO~1000℃
Any material can be used as long as it can withstand temperatures up to a temperature range of 100 to 100°C, and ceramic fibers, stainless steel fibers, etc. are suitable. Other materials such as carbon fiber and steel fiber can also be used, but carbon fiber requires special equipment to maintain a non-oxidizing atmosphere in the firing furnace, while steel fiber oxidizes a little more strongly and is slightly less durable. There are other problems such as anxiety. The fiber length of the heat-resistant short am material is preferably about 2 to 60 mm, particularly about 3 to 50 mm.

In addition to the above-mentioned components, admixtures such as a binder, a sizing agent, and bentonite, which are usually added during the production of cement products, may be appropriately added to the cement mortar.

According to the present invention, the molded body obtained by the casting method or the blow molding method is then glazed and then fired.

In the present invention, inexpensive frit glazes used for manufacturing tiles, ceramic roof tiles, novelty items, etc. can be used as they are. Furthermore, this is feldspar.

By appropriately blending raw materials such as clay, the # of the glazed surface can be improved.
It can improve weatherability, abrasion resistance, and chemical resistance.

Other 1: Glazes that can be used in the present invention include raw glaze and volatile glaze. Since various glazes can be used in the present invention, the desired color and gloss of the glazed surface can be obtained. .

In addition, 1. In the present invention, 2. Before or after the glazing step,
The molded body is heated to 100 to 600°C, preferably 300 to 400°C.
It is preferable to heat dry at ℃ for about 30 to 60 minutes. In other words, when cement hydrate is fired, water vapor and carbon dioxide gas are generated, so in order to remove these in advance, such heat drying is Do it. This heating drying may be performed separately from the main firing in the preheating section of the main firing furnace, but the heating drying and main firing are performed continuously in the firing section of the single firing furnace without any time gap between them. It is also possible to do so.

The firing time and firing temperature in the firing process of the present invention is determined depending on the type of glaze, but it is usually fired at 650 to 1000°C for 5 to 60 minutes.

The glazed fired product obtained by firing is cured in order to sufficiently hydrate and harden.Curing should be done in a state where the required amount of water can be sufficiently supplied, and it can be cured in air, humidity, water, etc.
Any method such as steam curing or autoclave curing may be used, and the curing conditions are appropriately determined depending on the properties and size of the glazed fired product.

The glazed cement product obtained by the method of the present invention has extremely high mechanical strength and a significantly high product value C1.

[Function] Due to the reinforcing effect due to the coexistence of the heat resistant short mis and the curing accelerator, the mechanical strength of the molded product obtained by the casting method or the spray molding method is greatly improved.

Ru.

In addition, since the mechanical strength of the compact before firing increases, thermal stress during the firing process and carbon dioxide generated due to hydration of silicate lime
It becomes possible to resist the internal stress caused by the decomposition and contraction of IL(OH)2, the expansion stress of microbubbles in the molded body, and the expansion stress due to vaporization of cement hydration water. Due to its presence, the internal stress is dispersed, so that cracks do not occur during firing, and a decrease in strength can be prevented.

Therefore, since high-temperature firing is possible, ordinary glazes can be used, and the final product obtained is.

Due to the reinforcing effect of heat-resistant short fibers and curing accelerator.

The result is a glazed cement product with extremely high mechanical strength, excellent weather resistance, abrasion resistance, and chemical resistance, and a beautiful glazed surface.

[Examples] The present invention will be explained in more detail by giving Examples and Comparative Examples below, but the present invention is not limited to the following Examples unless it exceeds the gist of the invention. The measured value in is the average value of three test results.

Example 1 100 parts by weight of ordinary Portland cement, curing accelerator (
Denka QT) 20 parts by weight, reaction inhibitor (Denka Setter) by weight, SUS stainless fiber (@0.3×
After kneading 7.5 parts by weight (thickness: 0.3 x length: 15 mm), 200 parts by weight of aggregate (porcelain chamotte 35 mesh under), and 35 parts by weight of water, the mixture was poured into a 1 x 5 x 25 cm mold and molded for 1 hour. I left it alone and left it alone. The obtained molded body was immediately preheated at 450°C and glazed with a boric acid glaze. After glazing, it was fired at a temperature of 860°C for 30 minutes. After that, it was immersed in water to absorb enough water, and then heated to 60°C.
After steam curing at 100% humidity for 3 days, a glazed cement product was obtained.

The obtained products include Tensilon (manufactured by Toyo Baldwin)
A load was applied at a speed of Inn/1m1n, and the bending strength was measured. The results are shown in Table 1.

For reference, the bending strength was also measured in the same manner for those obtained by steam curing at 60°C and 100% humidity for 3 days without firing after glazing, and the results are also listed in Table 1. did.

Example 2 A glazed cement product was manufactured in the same manner as in Example 1 except that SUS stainless fiber was used for the jilsffi needle part, and the bending strength was measured.

The results are shown in Table 1.

In addition, unfired products are steam-cured at 60℃ and humidity Zoo% for 3 days.
The bending strength was also measured for those tested for several days, and the results are shown in Table 1.

Comparative Example 1 A glazed cement product was produced in the same manner as in Example 1 except that no hardening accelerator and SUS stainless fiber were used, and the 1 bending strength was measured.

In addition, unfired products are steam-cured at 60℃ and 100% humidity for 3 times.
The bending strength was also measured for those tested for several days.

The results are shown in Table 1.

Comparative Example 2 A glazed cement product was produced in the same manner as in Example 2 except that no hardening accelerator was used, and the bending strength was measured.

The bending strength was also measured for unfired products that had been steam-cured at 60° C. and 100% humidity for 3 days.

The results are shown in Table 1.

Comparative Example 3 A glazed cement product was manufactured in the same manner as in Example 2 except that SUS fibers were not used, and the bending strength was measured. Further, the bending strength was also measured for unfired products that had been steam-cured at 60° C. and a humidity of 100% for 3 days.

The results are shown in Table 1.

Table 1 *1: Tonicity part *2: kgf/crn' As is clear from Table 1, the strength after firing and curing is higher than that of ordinary cement mortar with 15 parts by weight of stainless fiber alone (Comparative Example 2). ) is 32.9 kg compared to normal cement mortar (Comparative Example 1)
It shows an increase in the strength of f/crn', and the reinforcing effect of the stainless fiber is recognized. In addition, the one to which only a curing accelerator was added in parts at 20°C (Comparative Example 3) showed an increase in strength of 15.4 kgf/cm' compared to the one without the addition (Comparative Example 1), and the unfired curing amount The difference between the amount of curing and the amount of curing by firing, that is, the decrease in strength due to firing, is 23,3 (81,
7-58,4) kg f/crn' to 18
, 5 (112,3-73,8)kg f/c
It is confirmed that resistance to various internal stresses generated during the firing process is developed due to the reduction in rn' and the increase in the strength of the molded body before firing.

For this reason, when 15 parts by weight of stainless fibers and 20 parts by weight of a hardening accelerator are added to ordinary cement mortar, the strength is increased by the sum of the strength improvement due to stainless steel and ivar, and the strength improvement due to the hardening accelerator. That is, 4
8,3 (32,9+ 15.4)kg f/
It is expected that the strength of cr rn' will improve, and the strength will be 106
, 7 (58,4+48.3) kg f/crn'.

However, as is clear from the results of Example 2, which is an example in which 15 parts by weight of stainless fibers and 20 parts by weight of hardening accelerator were added to ordinary cement mortar, the strength was actually 162.4 kg f/c. rn'
This high value was achieved by simultaneously adding stainless fiber and hardening accelerator.

The difference between the actual 1lI4 value and the calculated value, i.e. 55, 7 (162
, 4-108, 7) It is recognized that a synergistic effect of "kg f / cr n" is expressed.Moreover, there is no decrease in strength due to firing, on the contrary, the strength increases, and the The amount of curing shows higher strength.This is due to the synergistic effect of the coexistence of stainless steel fiber and hardening accelerator, in addition to the respective effects of stainless fiber and hardening accelerator.
This proves that the strength of the molded body before firing is increased, its resistance to various internal stresses generated during firing is strengthened, and that this is due to the effective dispersion of internal stress by stainless fibers. It is.

As described above, according to the method of the present invention, the reinforcing effect of heat-resistant short fibers such as stainless steel fibers is efficiently exhibited,
The final glazed cement product is extremely strong.

Example 3 Ordinary Portland cement lOO insect acid part, hardening accelerator (
Denka QT) 20 parts by weight, 11 parts by weight of response agent (Denka Setter), SUS stainless fiber (ll@0.
Using 20 parts by weight of 3× thickness 0.3× length 25 mm), 200 parts by weight of aggregate (porcelain chamotte 35 mesh under) and 35 parts by weight of water, the same treatment as in Example 1 was carried out to produce a glazed cement product. Manufactured. The bending strength of this product was measured and found to be 183.6 kgf/crn''.

Example 4 100 parts by weight of sweat-permeable Portland cement, hardening accelerator (
Thoroughly knead 20 parts by weight of DENKA QT), 2 parts by weight of a retarder (DENKA SETTER), 100 parts by weight of aggregate (porcelain chamotte 35 mesh under), and 40 parts by weight of ice, and mix ceramic fiber (alumina fiber (Sumitomo Chemical) made)) 5
After spray molding to a thickness of 10 mm so as to have a fiber content of parts by weight, a molded product with a size of IX5 x 25 cm was cut out from this molded product, and glazed, fired and cured in the same manner as in Example 1. Manufactured cement products. The bending strength of this item was measured and was 178.9 kgf/cr.
It was n'.

[Effect] As described in detail below, the method for producing a glazed cement product of the present invention includes adding and mixing a specific amount of a hardening accelerator and a heat-resistant short fiber material to a cement mixture as a raw material. The initial mechanical strength of the compact before firing is improved, the mechanical strength of the glazed cement product is improved, and the casting method or the spray molding method is applied to the glazed cement product by rotation. It is.

According to the method of the present invention, (1) a glazed cement product with extremely high strength can be produced;

■ Conventionally, it was considered to be impractical due to a decrease in strength due to firing. Pouring molding and spray molding can be applied.

■ Because it can be fired at high temperatures, ordinary inexpensive glazes that are not phosphoric acid-based can be used, and it has excellent weather resistance, abrasion resistance, and chemical resistance. A beautiful glazed surface can be obtained.

■ The ability to apply the pour molding method increases the degree of freedom in the shape of the resulting glazed cement product.

■ Accelerates curing during the molding process, thereby shortening manufacturing cycles and increasing productivity.

(Φ Large-sized products can be manufactured at low cost because inexpensive molds can be used.

■ It becomes possible to manufacture large-sized glazed cement products that are difficult to mold by machine.

■ Since wooden molds can be used, costs can be reduced and production time can be shortened.

■ Since large amounts of aggregate can be used in pour molding,
Raw material costs can be reduced.

Various effects such as

Patent applicant Representative director of Inax Co., Ltd.
Teruzo Ina

Claims (2)

[Claims] (1) 100 parts by weight of cement, 1 to 2 parts of heat-resistant short fiber material
0 parts by weight, 10 to 30 parts by weight of hardening accelerator, and 50 to 30 parts by weight of aggregate.
After pouring and molding a cement mortar containing 500 parts by weight and applying a glaze to the surface of the obtained cement molded body,
A method for producing a glazed cement product, which comprises firing at a temperature of 650 to 1000°C and then curing. (2) A cement mortar containing 100 parts by weight of cement, 10 to 30 parts by weight of hardening accelerator, and 50 to 200 parts by weight of aggregate is mixed with a heat-resistant short fiber material having a fiber content of 1 to 10 parts by weight in terms of solid content. After applying glaze to the surface of the obtained cement molded body,
A method for producing a glazed cement product, characterized by firing at a temperature of °C and then curing.