JPS63144158A - Xonotlite base calcium silicate formed 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] <Industrial Application Field> The present invention relates to a xonotlite-based calcium silicate molded body used as a building material, and more specifically to a xonotlite-based calcium silicate molded body that has excellent strength and heat resistance. Regarding.

<Conventional technology and its problems> Zonotlite-based calcium silicate molded bodies containing xonotlite crystals as a main component have particularly excellent heat resistance. It is widely used in applications such as coatings.

The following four methods are mainly known as methods for producing xonotrite-based calcium silicate molded bodies.

■ Siliceous raw materials and calcareous raw materials, as well as additives to be added as necessary, are placed in powder form in a mold and molded, and then hydrothermally reacted in an autoclave to obtain a molded body (fF Publication No. 1983-25672). ).

■ After molding a raw material slurry consisting of a siliceous raw material, a calcareous raw material, water, and additives added as necessary, a molded body is obtained by a hydrothermal reaction in an autoclave (%
Comparative Example 2 of Publication No. 61-25672).

(2) A raw material slurry similar to (2) is heated to perform a preliminary reaction to produce a gel, and after the gel is molded, a hydrothermal reaction is performed in an autoclave to obtain a molded body.

■ A raw material slurry similar to ■ is subjected to a hydrothermal reaction while stirring in an autoclave to generate xonotlite crystals.
It is molded and dried to obtain a molded body (Special Publication Publication No. 45-257
Publication No. 71).

However, in the manufacturing method shown in (1) above, since the raw materials cannot be packed so densely, the bulk specific gravity of the obtained molded product is about 0.48 (%Koshō 61-256
(Refer to Experimental Example 2 in Japanese Patent No. 72), a molded article having a large bulk specific gravity cannot be obtained. Therefore, it is difficult to obtain a molded product with high performance in terms of strength. In addition, with the manufacturing methods shown in ■ and ■, molded bodies with high bulk specific gravity can be obtained, but the shrinkage rate of the resulting molded bodies when heated to a high temperature is greater than that of conventional xonotrite-based calcium silicate molded bodies. Become.

In other words, the heat resistance, which is a major feature of the xonotrite-based calcium silicate molded product, is reduced. Furthermore, in the production method shown in ■, the aggregate of xonotrite crystals produced by the hydrothermal reaction is extremely bulky (see Ceramics Association Journal 82 (3) 171 (1974)),
Similarly to the manufacturing method shown in , a molded article having a large bulk specific gravity cannot be obtained. Therefore, even with this manufacturing method, it is difficult to obtain a molded article with high performance in terms of strength.

For the reasons mentioned above, a xonotrite-based calcium silicate molded body that can be used in applications that require strength such as wall materials and flooring materials and has excellent heat resistance has not been obtained so far.

Means for Solving the Problems The present invention aims to obtain a xonotrite-based calcium silicate molded product that has the strength required for architectural wall materials and flooring materials and has excellent heat resistance. It is something.

That is, the present invention is made of xonotrite calcium silicate and an inorganic material, and has a bulk specific gravity of 0.80 or more,
The xonotrite-based calcium silicate molded article is characterized in that the residual linear shrinkage rate after heating is 1.0% or less.

The xonotrite calcium silicate referred to in the present invention is usually produced from a silicic acid raw material and a calcareous raw material by a hydrothermal reaction, and is composed of xonotrite crystals and an amorphous substance called C8H gel. The physical properties of the molded article vary depending on the proportions of the xonotlite crystals and C3H gel.

@Ic When heat resistance is required, it is necessary to have a large amount of xonotrite crystals.

The inorganic material that is one of the components of the molded article of the present invention needs to have heat resistance. It also has the effect of improving the strength of the molded product, and in particular, it is necessary to have the effect of suppressing a decrease in the strength of the molded product when the molded product is heated to a high temperature. However, as described below, these inorganic materials are mixed with the raw materials for making xonotrite calcium silicate and water and placed under hydrothermal conditions, but at this time a chemical reaction occurs and components with poor heat resistance are produced. I don't like things like that. For example, some types of chamotte react during hydrothermal reactions to produce tobermorite crystals that have poor heat resistance, which is not preferred. Examples of inorganic materials preferable as a component of the molded article of the present invention include rod-shaped wollastonite, plate-shaped mica, and fibrous asbestos/ceramic fiber. Further, the content of the inorganic material cannot be absolutely limited because the effects vary depending on the type of inorganic material. Inorganic materials not only need to improve strength, but also have the effect of reducing residual linear shrinkage after heating, which is the problem of the present invention, so it is preferable to take this point into account when determining the content. . As a tentative guideline for the content, it should be at least 5% of the total amount of solid raw materials for making xonotrite calcium silicate.
By weight, preferably from 10 to 50% by weight.

The bulk specific gravity of the bottom body of the present invention must be 0.80 or more, preferably 1.00 to 1.70. Bulk specific gravity is 0
．． This is because if it is less than 80, it is difficult to obtain the strength required for a wall material without reinforcement with reinforcing bars or the like. Further, in order to maintain the strength of the molded product after being heated to a high temperature, it is necessary to have a bulk specific gravity greater than O or SO.

Further, the molded article of the present invention needs to have a residual linear shrinkage rate of 1.0 or less after heating measured under the conditions shown below.

If it is less than 1.0 cm, the decrease in strength of the molded product can be kept to a small value even if it is heat-treated at 1000°C, which is the maximum operating temperature for xonotrite-based calcium silicate molded products. It is. The method for measuring the residual linear shrinkage after heating is as shown below.

Measuring equipment: Rigaku Denki thermomechanical analyzer high-temperature compression TM
A8141H Load on sample...so, 9af/d (height direction temperature increase rate (room temperature → 1000'C)...20℃/min Holding temperature...1000℃ Holding time...5 minutes cooling down Speed (1000°C→room temperature door...10°C/min) The residual linear shrinkage rate was calculated by measuring the amount of shrinkage in the height direction and using the following formula (I).

The method for developing a xonotlite-based calcium silicate molded body of the present invention uses particle size Zo as a silicic acid raw material.

μ or less, and the weight loss rate in NaOH aqueous solution measured under the conditions shown later is 1.0 to 10.0 μ, preferably 2.0
Using slaked lime as the calcareous raw material, silica stone with a CaO/SiO□ (molar ratio) of ~5.0- is 1. Mix until OK. After adding an inorganic material and, if necessary, a water reducing agent, the mixture is mixed with water to form a uniform slurry. This slurry is molded and the water content just before the hydrothermal reaction is adjusted so that the water/solid content (IIT ratio) is 1.0 or less. A calcium acid molded body can be obtained.

The weight loss rate of silica stone in NaOH aqueous solution is measured as follows:
It is as shown below.

NaOH aqueous solution concentration・・・・・・・・・・・・・・・
・・・・・・10wt% NaOH aqueous solution temperature・・・・・・
・・・・・・・・・・・・・・・100℃silica/NaO
H aqueous solution (weight ratio)...1150 Immersion time...
・・・・・・・・・・・・・・・・・・・・・・・・
......The weight loss rate for 4 hours (standing still) was calculated by measuring the xi of the remaining silica stone and using (If) 2 below.

<Example> Hereinafter, the present invention will be specifically explained using examples.

Here, various physical property values were measured by the following methods.

Bulk specific gravity: Determined from the weight and volume of a 4×4×16 cm specimen after drying it in an electric dryer at 110° C. until it reached a constant weight.

Bending strength: 4x4x16ffi specimen at 20℃
After being left in a room with a relative humidity of 65% for 7 days or more, measurements were taken under the conditions of a span of 10 exe and a loading rate of 0.5 cm/sequence.

Residual linear shrinkage rate after heating: Measured according to the method for measuring the residual linear shrinkage rate after heating described above.

Weight loss rate of silica stone in NaOH aqueous solution: Measured under the conditions for measuring the weight loss rate of silica stone in NaOH aqueous solution.

Example 1 Kokuji silica with a particle size of 20 to 44μ (total reduction rate of 2.3% in NaOH aqueous solution) and slaked lime were mixed into Cab/5t02 (
5 was mixed so that the molar ratio 2 was 1.0, and wollastonite (manufactured by Nippon Creates σD, trade name: Ken Moritsu N) was added to this by 50 weight by dividing the total amount of Kokuji silica and slaked lime. % added. Furthermore, add 60% by weight of water to the total solid content, and add a water reducing agent (manufactured by Hamano Industries, product name:
HP-100) was added in an amount of 2% by weight based on the total solid content, and thoroughly mixed to form a uniform slurry. After pouring this slurry into a mold and molding, the mold was placed in an autoclave and subjected to a hydrothermal reaction at 210° C. for 15 hours to obtain a molded product. The X-ray diffraction pattern of the obtained molded product is shown in FIG.

The crystals constituting the bottom body were xonotrite crystals and wollastonite crystals. Various physical properties of this molded body are shown in Table 1.

Example 2 Asbestos (manufactured by Lake Co., Ltd.,
Product name: Lake 6D-4) 30% by weight, 60% by weight of water
A whole molded body was obtained in the same manner as in Example 1, except that the amount of the molded product was reduced to 65% by weight. The X-ray diffraction pattern of the obtained molded product is shown in FIG. The crystals constituting the molded body were xonotrite crystals and chrysotile crystals, which are a constituent of asbestos. Table 1 shows various physical property values of this molded article.

Comparative Example 1 Kokuji silica with a particle size of 20 to 44 μm (weight loss rate in NaOH aqueous solution: 2.3 μm) and slaked lime were blended with CaO/SiO□ (mole ratio was 1.0). Water was added in an amount of 60% by weight based on the total solid content, and a water reducing agent (manufactured by Hamano Kogyo ■, trade name: HP-100) was added in an amount of 2% by weight based on the total solid content and mixed. This slurry was poured into a mold and molded, and the mold was subjected to a hydrothermal reaction at 210°C for 15 hours in an autoclave to obtain a molded product. X-ray diffraction of the molded product obtained A diagram is shown in Fig. 3. The crystals constituting the molded body were xonotrite crystals. The various physical property values of this molded body are shown in Table 1.

Comparative Example 2 A molded article was obtained in the same manner as in Example 1, except that wollastonite was changed to porcelain chamotte and 60% by weight of water was changed to 35% by weight. The X-ray diffraction pattern of the obtained molded product is shown in FIG. The crystals forming compact 1-* were tobermorite crystals and α-quartz. Table 1 shows various physical property values of this molded article.

Table 1 1) Heating at 1000℃ for 5 minutes 2) No measurements were taken because the specimen was severely damaged.

<Effects of the Invention> The present invention is a xonotrite-based calcium silicate molded product that has the strength required for architectural wall materials and flooring materials and has excellent heat resistance. Furthermore, by applying a glaze to the surface of this molded body and firing it at a high temperature, a ceramic coated plate having the strength required as a wall material or flooring material can be obtained.

[Brief explanation of the drawing]

Figure 1 is an X-ray diffraction diagram of the molded product obtained in Example 1,
The figure shows an X-ray diffraction diagram of the molded body obtained in Example 2, Figure 3 is an X-ray diffraction diagram of the molded body obtained in Comparative Example 1, and Figure 4 shows the X-ray diffraction diagram of the molded body obtained in Comparative Example 2. It is an X-ray diffraction diagram. Patent applicant: Asahi Kasei Industries, Ltd. Figure 1 e Figure 2

Claims (1)

[Claims] A xonotrite calcium silicate molded body made of xonotrite calcium silicate and an inorganic material, having a bulk specific gravity of 0.80 or more and a residual linear shrinkage rate of 1.0% or less after heating.