JP2665942B2 - Calcium silicate hydrate compact and method for producing the same - Google Patents

Description

The present invention relates to a calcium silicate hydrate compact and a method for producing the same.

(Prior art) In recent years, a large number of calcium silicate hydrate compacts have been manufactured. These calcium silicate compounds have excellent weather resistance and fire resistance, and are used not only as fillers for plastics, catalysts, adsorbents, etc. as industrial materials, but also as interior and exterior materials, heat insulating materials, sound absorbing materials, and fire-resistant coatings. It is widely used for building materials such as wood and lightweight cellular concrete (ALC).

In the manufacturing methods of calcium silicate hydrate-based industrial materials, interior and exterior materials, heat insulation materials, sound absorbing materials, fireproof coating materials, and ALC, all of the production methods for calcium silicate are performed by reacting siliceous raw materials and calcareous raw materials in an autoclave. Either a method in which the slurry is pressure-formed and dried and hardened after the formation of crystals, or a method in which the slurry is pre-heated, pressure-formed in a gelled state, and dried after autoclaving. However, in order to produce these calcium silicate hydrates and obtain a molded body, it is necessary to apply heat and pressure for a long time, and it is necessary to shorten the process. Also, since the molded body obtained in this way is used for building materials, etc., it is necessary to have high strength,
There is also a demand for improved performance in terms of strength.

(Problems to be Solved by the Invention) An object of the present invention is to provide a method for producing a calcium silicate hydrate compact having excellent strength in a short reaction time, and to provide the obtained calcium silicate hydrate compact. is there.

(Means for Solving the Problems) In the present invention, when a calcareous raw material, a siliceous raw material and water are subjected to a hydrothermal reaction under high-temperature and high-pressure saturated steam, the calcareous raw material and the siliceous raw material are converted into CaO and SiO _2. Silicic acid mainly composed of zonotrite, characterized in that the former is blended at a molar ratio of 0.8 to 1.2 with respect to the former, and potassium titanate is added and molded, followed by a hydrothermal reaction at a reaction temperature of 180 to 220 ° C. The present invention relates to a method for producing a calcium hydrate molded product and a calcium silicate hydrate molded product containing potassium titanate and mainly composed of zonotrite.

The potassium titanate used in the present invention is generally represented by K ₂ O.nTiO ₂ .mH ₂ O (n and m are real numbers of 1 <n ≦ 8 and 0 ≦ m ≦ 4, respectively). The amount of potassium titanate is usually about 3 to 40% of the total of siliceous raw material and calcareous raw material.
(% By weight), preferably about 5 to 30%.

The siliceous raw material used in the present invention may be any raw material used in a conventional hydrothermal reaction, and examples thereof include silica stone, diatomaceous earth, shirasu, clay, silica sand, fly ash, silica flower, and zeolite. Slaked lime, quicklime, Portland cement, slag, and the like can be used as the calcareous raw material. The ratio of these siliceous material and calcareous material are CaO, preferably the latter to 0.8 to 1.2 with respect to the former in a molar ratio in terms of SiO _2. These raw materials are usually prepared in the form of an aqueous slurry. The appropriate slurry concentration is about 3 to 10%. The prepared slurry is heated and reacted in an autoclave. Heating reaction is usually 2
Done in stages. In the first step, a gelled state is created by heating at 90 to 100 ° C. for about 30 minutes to 2 hours, and then filled into a press mold and dewatered under pressure to mold. The molded product is subjected to a heating reaction at 180 to 220 ° C. in an autoclave to obtain a calcium silicate hydrate molded product. However, it may be performed by one-stage heating.

The calcium silicate hydrate produced in the present invention has mainly the crystal structure of zonotolite.

In the present invention, it is possible to use a fiber reinforcing material in addition to these raw materials. In this case, examples of the fiber reinforcing material include alkali-resistant glass fiber, rock wool fiber, carbon fiber, synthetic fiber, pulp, metal fiber, organic fiber, and whiskers. These reinforcing materials are used in a mixture with a calcareous raw material, a siliceous raw material, and the like, and the compounding amount is usually preferably about 1 to 30% based on the total of the calcareous raw material and the siliceous raw material.

(Example) Hereinafter, an example will be described in more detail. “Parts” simply means “parts by weight”.

Example 1 Using slaked lime (Kashino lime) and silica stone (Tokai Kogyo), each was pulverized, and the powder passed through 180 mesh was adjusted to 1.0 with a molar ratio of CaO / SiO ₂ to 100 parts of the adjusted raw material. 5 parts of potassium titanate whiskers (Otsuka Chemical Co., trade name: Teismo D) and 1500 parts of water were added and stirred to obtain a uniform slurry. This slurry is placed in an autoclave at 95 to 100 ° C.
After heating for 2 hours to form a gel, the mixture was filled into a press mold, dewatered under pressure and molded. The molded product was reacted at 200 ° C. for 6 hours in an autoclave, taken out and dried at 110 ° C. overnight. The bulk specific gravity of this molded product was 0.37.

Examples 2 to 4 10 parts each of potassium titanate whiskers, 20 parts,
A molded product was obtained in the same manner as in Example 1 except that 30 parts were added.

Example 5 A molded article was obtained in the same manner as in Example 1 except that the reaction time at 200 ° C. in the autoclave was changed to 3 hours.

Comparative Example 1 A molded body was obtained in the same manner as in Example 1, except that the potassium titanate whisker was not added and the amount of water was changed to 300 parts.

Comparative Example 2 A molded article was obtained in the same manner as in Comparative Example 1, except that the reaction time at 200 ° C. in an autoclave was changed to 12 hours.

Table 1 shows the bending strength (measured by JIS A 1408) of the molded articles obtained in Examples 1 to 5 and Comparative Examples 1 and 2.

(Effect of the Invention) In the present invention, when a calcium silicate hydrate molded article is produced, by adding potassium titanate, a high-strength molded article can be obtained in a short reaction time.

Claims (3)

(57) [Claims] 1. A calcium silicate hydrate compact comprising potassium titanate and mainly consisting of zonotrite. 2. The calcium silicate according to claim 1, further comprising one or more of alkali-resistant glass fiber, rock wool fiber, carbon fiber, synthetic fiber, pulp, metal fiber, organic fiber and whisker as a fiber reinforcing material. Hydrate molded body. 3. A hydrothermal reaction of a calcareous raw material, a siliceous raw material, and water under a high-temperature, high-pressure saturated steam, wherein the lime-chamber raw material and the siliceous raw material are converted into CaO and SiO ₂ in a molar ratio to the former. The latter is blended at a ratio of 0.8 to 1.2, and after adding potassium titanate and molding, a calcium silicate hydrate molded body mainly composed of zonotlite characterized by being subjected to a hydrothermal reaction at a reaction temperature of 180 to 220 ° C. Production method.