JP2520913B2 - Calcium silicate compact and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention is lightweight, has excellent bending strength, is excellent in inferiority, heat resistance, and water resistance, and is suitable for building materials such as synthetic wood. The present invention relates to a calcium silicate compact and a method for producing the same.

<Prior art> Since conventional synthetic wood is mainly made of synthetic resins such as polystyrene, polyethylene, polypropylene, and polyurethane, it easily deforms when heated to high temperatures, causing smoke or burning. have.

In order to improve such a defect, various ideas and proposals have been conventionally made. For example, synthetic resin, calcium carbonate, when adding an inorganic filler such as gypsum, a method of increasing the addition ratio, a method of filling the synthetic resin with calcium silicate hydrate, calcium silicate as the main raw material,
Reinforcing fibers are added and dispersed in this, and after pressure dehydration molding,
A method of drying, a method of impregnating the calcium silicate molded plate with a resin, or a method of adding and dispersing a styrene-butadiene copolymer latex containing calcium silicate as a main raw material and containing a carboxyl group, a cationic polymer flocculant and a reinforcing fiber. A method of forming and drying (Japanese Patent Laid-Open No. 60-246251) is known.

<Problems to be Solved by the Invention> However, in the method of adding an inorganic filler such as potassium carbonate or calcium silicate hydrate to the synthetic resin, the bulk specific gravity of the obtained molded article becomes large, and further, If the bulk specific gravity of natural materials is attempted, the strength of the molded product will be significantly reduced, and in the method of adding and dispersing reinforcing fibers in calcium silicate and performing pressure dehydration molding, calcium silicate Due to its fine porous structure, it absorbs a large amount of water and does not have the same processability as natural wood. Furthermore, the process of impregnating a calcium silicate molded plate with a resin improves the processability but requires a large amount of resin. However, it has a drawback that the heat resistance is significantly reduced.

On the other hand, although the molded article disclosed in JP-A-60-246251 has improved these drawbacks, the flexural strength of the molded article is significantly lower than that of natural wood and its use is extremely limited. Had inconvenience.

<Means for Solving Problems> The inventors of the present invention have made extensive studies in view of the above problems, and as a result, in a calcium silicate compact formed by stacking matrix layers containing reinforcing short fibers in multiple stages. Therefore, they have found that these problems can be solved by stacking in multiple stages and integrally molding while maintaining the interfaces of the raw material slurries having different fiber contents, and arrived at the present invention.

That is, an object of the present invention is to provide a calcium silicate compact and a method for producing the same, which is lightweight, has excellent flexural strength, and is excellent in inferiority, heat resistance and water resistance. The purpose is a calcium silicate compact having a multilayer structure in which a matrix layer containing reinforcing short fibers and calcium silicate hydrate is laminated in multiple stages,
A matrix layer having a high fiber content and a matrix layer having a low fiber content are alternately laminated and integrally molded,
The fiber content of the matrix layer having a high fiber content is 3 to 20 parts by weight based on 100 parts by weight of the solid content of calcium silicate hydrate, and the fiber content of the matrix layer having a low fiber content is calcium silicate. 1 to 10 parts by weight based on 100 parts by weight of the solid content of the hydrate, and the fiber content of the matrix layer having a high fiber content is at least twice the fiber content of the matrix layer having a low fiber content. And a method for producing the same. More easily achieved.

 Hereinafter, the present invention will be described in detail.

The calcium silicate hydrate used in the present invention is obtained by hydrothermally synthesizing a calcareous raw material such as quicklime and a siliceous raw material such as silica stone. Usually, from crystalline substances called xonotlite and tobermorite, CSH
I, CSH II, and even amorphous ones can be used in a wide range.

As its manufacturing method, calcareous raw material and siliceous raw material are Ca
A method is employed in which an aqueous slurry adjusted so that the molar ratio of O and SiO ₂ is almost equal is heated to 160 ° C. or more under pressure and reacted. In the present invention, this slurry can be used as it is, but can also be used by adding water to a powder obtained by drying. The solid content concentration of the calcium silicate hydrate in the slurry is not particularly limited, but is preferably 10% or less.
8% is preferable.

Next, the reinforcing fiber used in the present invention may be any organic or inorganic fiber. For example, as the organic fiber, nylon, polyester vinylon, lelan, aramid, etc. are used, and as the inorganic fiber, steel, glass fiber, carbon fiber, SiC fiber, alumina fiber, etc. are used, of which tensile strength 150 kg / mm ² or more, Young's modulus 5
Those having a ton / mm ² or more are preferable.

The form of the reinforcing fiber is preferably a short fiber, and the fiber length thereof is 1 to 50 mm, preferably 5 to 30 mm.

In the present invention, slurries having different contents of reinforcing short fibers are used, and the number of slurries is 2 to 4, preferably two kinds of slurries. For example, one type uses a slurry having a high content of reinforcing fibers, and the other type uses a slurry having a low content. At this time, the amount of the reinforcing fiber added is such that when the content of the slurry is high, the calcium silicate solid content is increased.
3 to 20 parts by weight with respect to 100 parts by weight, on the other hand, in the case of a slurry having a low content, 1 to 10 parts by weight can be added and used. The fiber content ratio of each slurry is preferably twice or more the fiber content based on the slurry having a low content.

These slurries are laminated in multiple stages and integrally molded to obtain the calcium silicate molded body of the present invention, but the total content of the reinforcing short fibers to the molded body is usually 30% by weight or less, aqueous, molded Considering the properties, it is preferably 10% by weight or less.

Furthermore, carboxylated SBR latex may be added when the reinforcing short fibers are added to the calcium silicate slurry. By adding the latex, it is possible to improve the bending strength and toughness of the molded product and further the processability. The amount of latex added is 2 to 2 in terms of solid content based on 100 parts by weight of dry solid content of calcium silicate hydrate.
It is preferable to add 5 parts by weight. While increasing the amount of addition improves the strength of the obtained molded product, it causes problems such as a decrease in incombustibility, an increase in bulk specific gravity, and an increase in cost.

Further, when the latex is added, in order to promote the fixing of the latex particles and the crystal particles of calcium silicate,
A polymer flocculant may be used, or an antifoaming agent may be added to prevent foaming due to the emulsifier in the latex.

Further, when adding the latex, a coupling agent may be used in order to promote fixation with the reinforcing fiber.

These additives may be added in a very small amount, and are usually used in an amount of 0.1 to 1 part by weight based on 100 parts by weight of the solid content of the latex.

The slurry thus obtained is subjected to dehydration molding by a method such as pressurization. At this time, after the slurry is fed into the mold of the molding machine, the interface is not disturbed on the upper part of the slurry. Further, it is preferable to supply other slurries having different fiber contents, pressurize and dehydrate as they are, and integrally mold them. By using the molding method, 2
A molded product having a multi-layered structure of more than one layer can be obtained, but a three-layered structure is preferable from the viewpoint of physical properties and productivity of the molded product.

More preferably, they are integrally molded so that a matrix layer having a high fiber content is laminated on both surfaces of a matrix layer of calcium silicate having a low fiber content.

The drying temperature after molding is usually 100 to 180 ° C, preferably 105 to 150 ° C, and the drying time is usually 5 to 15 hours. If the drying temperature is too low or the drying time is too short, water remains, which lowers the bending strength and increases the shrinkage rate of the molded product. On the other hand, if the drying temperature is too high or the drying time is too long, the molded product becomes hard and the toughness of the molded product is impaired.

<Examples> The present invention will be described in more detail with reference to Examples and Comparative Examples.

(Example 1) Quicklime (CaO: 96.2%) 49.6 warm water was added to the parts by weight hydrated consumption, and slaked lime slurry, silica in the slurry (SiO ₂ 9
6.4%) 50.4 parts by weight are added, and the total amount of water is 27.5 based on the solid content.
Water was added to make the weight twice, and this slurry was added at 15 kg / cm ²
The reaction was carried out under water vapor pressure for 4 hours to obtain zonotolite calcium silicate hydrate.

For 100 parts by weight of the dry solid of this calcium silicate hydrate, carbon fiber (tensile strength 310 kg / mm) was used as reinforcing short fiber.
² , Young's modulus of 23 ton / mm ² ) was added and mixed at a ratio shown in Table 1 to obtain slurry A. Similarly, a slurry B shown in Table-1 was prepared.

These slurries are supplied in order of A, B, A into the mold of the molding machine so as not to disturb the interface of the upper part of each slurry, pressurize and dehydrate as they are, and integrally mold, then at 1
It was dried for 0 hours.

The bending test results of the obtained molded body are shown in Table-2. still,
The bending test was carried out by using the central one-line loaded three-point bending test method, and the dimensions of the test piece were 30 cm in length, 5 cm in width, 3 cm in thickness, and 22 cm in bending span.

(Example 2) Using the same carbon fiber as in Example 1, a carboxylated SBR latex (“NiPol” 2570 × 5: manufactured by Zeon Corporation) was added to a calcium silicate slurry to obtain a calcium silicate solid content of 100. 7 parts by weight in terms of solid content was added to parts by weight to obtain slurries C and D shown in Table 1. Table 2 shows the test results of the molded product obtained in the same manner as in Example 1 except that the order of supply to the molding machine mold was C, D, and C.

(Example 3) Test results of a molded body obtained in the same manner as in Example 1 except that slurry E and F shown in Table 1 were used and E, F, and E were supplied in this order to a molding machine die. It shows in Table-2.

(Example 4) A table showing the test results of a molded body obtained in the same manner as in Example 1 except that the slurries G and H shown in Table 1 were used and G, H, and G were supplied in this order to the molding machine mold. -2.

Example 5 Using the same slurries A and B as in Example 1, A, B, A,
B and A are supplied in this order to the molding machine die, and five layers are formed,
Table 1 shows the test results of the molded body obtained in the same manner as in Example 1.
It is shown in FIG.

(Comparative Example 1) Table 2 shows the test results of a molded body obtained in the same manner as in Example 1 except that the slurry I shown in Table 1 was used and supplied to the molding machine die as it was.

(Comparative Example 2) Table-2 shows the test results of the molded product obtained in the same manner as in Comparative Example 1 except that the slurry J shown in Table-1 was used.

(Comparative Example 3) The slurries A and B shown in Table 1 were separately supplied to a mold of a molding machine, pressurized and dehydrated to obtain a molded body having a bulk specific gravity of about 0.1 A2.
I made one sheet, B1 sheet.

These molded bodies were laminated in the order of A, B, A, and again pressurized and dehydrated by a molding machine to obtain the molded body obtained in Example 1,
A molded product having the same bulk specific gravity was obtained.

Hereinafter, the test results of the molded body obtained in the same manner as in Example 1 are shown in Table-2.

<Effects of the Invention> According to the present invention, it is possible to obtain a calcium silicate molded product having an unprecedentedly excellent bending strength without impairing the original advantages of excellent incombustibility, heat resistance and water resistance. Also, since it has the advantage that the physical properties can be adjusted freely without changing the total fiber content, it can be used in various applications and is effective in improving productivity.

Claims (4)

(57) [Claims] 1. A calcium silicate compact having a multi-layer structure in which matrix layers containing reinforcing short fibers and calcium silicate hydrate are laminated in multiple stages, and a matrix layer having a high fiber content, A matrix layer having a low fiber content is alternately laminated and integrally molded, and the fiber content of the matrix layer having a high fiber content is 3 to 20 parts by weight based on 100 parts by weight of the solid content of calcium silicate hydrate. The fiber content of the matrix layer having a low fiber content is 1 to 1 with respect to 100 parts by weight of the solid content of calcium silicate hydrate.
A calcium silicate compact, which is 0 parts by weight and has a fiber content of a matrix layer having a high fiber content that is at least twice the fiber content of a matrix layer having a low fiber content. 2. The calcium silicate compact according to claim 1, wherein the surface layer having a multi-layer structure formed by stacking in multiple stages is a matrix layer having a high fiber content. 3. A method for producing a calcium silicate compact having a multi-layer structure in which a matrix layer having a high fiber content and a matrix layer having a low fiber content are laminated and integrally molded, the reinforcing short fiber and the calcium silicate. A slurry containing a hydrate and having a high fiber content of 3 to 20 parts by weight with respect to 100 parts by weight of the solid content of calcium silicate hydrate, and a solid content of calcium silicate hydrate of 100 The fiber content is 1 to 10 parts by weight with respect to parts by weight. The slurry having a low fiber content (and the fiber content of the slurry having a high fiber content is twice or more the fiber content of the slurry having a low fiber content. ) Are laminated in multiple stages in a mold, and while pressurizing and dehydrating while substantially maintaining the slurry interface, integrally molding, and then drying, a method for producing a calcium silicate compact. . 4. The method for producing a calcium silicate compact according to claim 3, wherein the raw material slurry contains a carboxylated SBR latex.