JPS5855103B2 - Manufacturing method of cement composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a novel cement composition.

More specifically, a cement composition is prepared by blending a hard granular material that is more suitable for cement than silicate minerals or carbonate minerals, artificial inorganic fibers such as glass fiber ore, and a synthetic resin emulsion that is miscible with cement. This relates to the manufacturing method, and by adding water and stirring and mixing, this yA product can exhibit excellent performance as a building material such as slate boards.

Asbestos slate boards, which have been widely used as building materials, are mainly composed of cement and asbestos, and their composition is mainly 85 parts cement to 15 parts asbestos.

(JIS A3403 Asbestos Slate Board Slate is widely used due to its practically acceptable performance and reasonable price, but there is a need for improvement in terms of strength and workability.

In other words, when used as a roofing material, it is strong enough to support the weight of workers to ensure safety, does not crack when cut, nailed, etc., and has a nail repellent effect. If a slate plate with good workability can be obtained, it is expected that its uses will further increase.

Traditionally, high-quality asbestos for building materials such as asbestos slate has been heavily dependent on foreign production, but these high-quality resources have recently been depleted, and there is a need to improve the sanitary aspects of the working environment in which this material is handled. , the price required to obtain it has a marked tendency to rise.

Research has been carried out on the use of glass fibers, fibers, and other artificial fiber materials for slate boards as a substitute for asbestos.

Industrially produced glass fibers are more homogeneous and have much greater tensile strength than asbestos, so there is a possibility that a large reinforcing effect can be achieved with a small amount of addition.

For example, it is known that the strength of plastic materials can be significantly increased by incorporating glass fibers.

However, when glass fiber is mixed into cement, it has the following drawbacks and has not been put to practical use.

Firstly, even if glass fiber and rock wool are mixed into cement,
Unlike asbestos, it is difficult to disperse and mix evenly, and it tends to harden into lumps, so it does not have a sufficient reinforcing effect.

Second, since glass fibers and rock wool are obtained by melt spinning, their surfaces are smooth and have poor adhesion to cement, making them ineffective as reinforcing materials.

Thirdly, glass fibers generally have poor resistance to the alkalinity of the matrix, resulting in a lack of durability.

The present invention not only overcomes these drawbacks of cement molded products containing artificial inorganic fibers, but also succeeds in providing superior strength and workability over conventional molded products containing asbestos.

That is, the present invention uses 100 parts by weight of cement, 1 to 20 parts by weight of artificial inorganic fibers, 10 to 50 parts by weight of hard granules that have passed through 30 meshes and contains silicate minerals or carbonate minerals, and polymerizable In preparing a cement composition by blending with 0.2 to 20 parts by weight of a synthetic resin emulsion obtained by emulsion polymerization of a hexamer having an unsaturated group, artificial inorganic fibers and hard granules are added in advance. The present invention relates to a method for producing a cement assembly hψ, which is characterized in that the mixture is sufficiently and uniformly stirred and mixed together with the above-mentioned synthetic resin emulsion and mixed into cement.

The key point in carrying out the present invention is that when adding artificial inorganic fibers to cement powder, the hard granules that are stronger than silicate minerals or carbonate minerals, which are to be the aggregate of cement, and the artificial inorganic fibers are stirred and mixed so that the artificial inorganic fibers are sufficiently uniform. The process involves adding a synthetic resin emulsion that can be mixed with cement, stirring and mixing with water, and molding.

The term "cement" as used herein means an inorganic binding agent that hardens in the presence of water, such as Portland cement, pozzolan cement, slag cement, and alumina cement.

Japanese Patent No. 316,896 shows that artificial inorganic fibers can be uniformly dispersed in cement by mixing hard granules such as crushed stone, gravel, and sand with artificial inorganic fibers.

The present inventors have found that talc-containing peridotite,
When silicate minerals or carbonate minerals such as serpentine and silicate clay are used as granules, preferably 30 meshes or more (passing 30 meshes), in addition to the above-mentioned dispersion effect of artificial inorganic and organic fibers, synthetic resin emulsions described below can be obtained. It has been found that when using these, the mutual compatibility becomes good and a cement molded product with excellent physical properties can be obtained.

On the other hand, it is well known that adding a synthetic resin emulsion to cement can increase the strength, prevent cracks, and improve water and chemical resistance of molded products (for example, Japanese Patent Publication No. 35-17
669).

There are many commercially available synthetic resins for mixing cement that can be used for this purpose, such as rubber latex, acrylic ester emulsion, vinyl acetate emulsion, and vinyl chloride emulsion.

Among these synthetic resins, the present inventors mainly emulsified monomers having polymerizable unsaturated groups such as vinyl acetate, methyl methacrylate, ethyl acrylate, butyl acrylate, vinyl chloride, styrene, ethylene, and propylene. It has been found that when a synthetic resin emulsion obtained by polymerization is mixed with artificial inorganic fibers and cement and used, in addition to the above-mentioned crack prevention effect and strength increasing effect, it is also effective in improving the adhesion between the cement and the fibers.

That is, the gist of the present invention is that it has been discovered that the artificial inorganic fiber acts as an effective reinforcing material in cement molded products due to the synergistic effect of the combined use of hard granular material and synthetic resin.

In addition, hard granules made of silicate minerals or carbonate minerals,
When the above synthetic resin emulsion is used in combination, the durability of the glass fibers mixed in the cement is also positively affected.

To obtain excellent effects by adding the above-mentioned artificial inorganic fibers, hard granules, and synthetic resin emulsions to cement, the appropriate amount is 1 to 20 parts by weight of artificial inorganic fibers per 100 parts by weight of cement. , 10 to 50 parts by weight of hard granules, and 0.2 to 20 parts by weight of synthetic resin emulsion (in terms of resin content).

Furthermore, Japanese Patent No. 316896 describes an artificial inorganic fiber mixture material characterized in that artificial inorganic fibers pulverized in the presence of hard granules are added to cement.

In contrast, in the present invention, it is sufficient to stir and mix the artificial inorganic fibers and hard granules so that they are sufficiently uniform before mixing with cement, and even if the fibers are actually pulverized, they are not pulverized. There is no need to intentionally mix them.

The present invention will be explained in more detail with reference to Examples below.

Example 1 Glass fibers and hard granules in the amounts shown in Table 1 were thoroughly mixed using a rotary grinding mixer, and then cement, synthetic resin emulsion, and water were added and mixed with stirring.

For comparison, we also prepared samples containing asbestos.

These cement mixtures are made into plate shapes using wire mesh,
It was squeezed at a pressure of 2 kg/- and then pressed and molded at a pressure of 30 ky/min.

The molded product was kept moist for 7 days and then air-dried for 1 month.

The impact strength and bending strength of the slate plate obtained by the above manufacturing method were measured.

The results are shown in Table 2.

The materials and test conditions used are as follows.

Cement; Portland cement hard granular material; talc-containing peridotite (produced in Koyo-cho, Hiki-gun, Saitama Prefecture) approximately 200 mesh glass fiber; Asahi Glass Fiber Glass Long Chop Strand 830A (fiber length 25λ) C synthetic resin emulsion; a-Sevian A-4500 (manufactured by Daicel)
Acrylic copolymer emulsion resin content: 40 b-Sepian A-387 (manufactured by Daicel) Modified vinyl acetate emulsion, resin content: 55φ Bending strength: Test piece Length 127 mm x Width 127 mm x Thickness 8.5 ± 0.5 mm Point: Apply this load and bending speed 3m
m/min impact strength; test piece length 64rn1rL x width 12.7m
m×thickness 8.5±0.5 mm phizont impact strength, no non-chip The numerical values in Table 2 are the average values of the values measured for five samples.

Samples ml, A2, and A3 can be nailed,
The nails that were driven in were firmly fixed.

Example 2 Glass fibers and hard granules in the amounts shown in Table 3 were thoroughly mixed using a rotary grinding mixer, then cement, aggregate, synthetic resin emulsion, and water were added, and after stirring and mixing, the cement molding surface was mixed. was prepared, and its bending strength and compressive strength were measured.

The results are shown in Table 4. The materials and test methods used are as follows.

Cement, glass fiber, synthetic resin emulsion; same hard granular material as in Example 1; crushed tuff (produced in Arashiyama-cho, Hiki-gun, Saitama Prefecture) approximately 2
00 mesh aggregate: River sand (saitama prefecture rough sand) 2.5 mm sieve molding and test method: Mortar molding surface, preparation conditions and strength test method shown in JIS R5201 (Physical test method for cement) .

The numerical values in Table 3 are average values for three samples each released 7 days and 28 days after molding.

Claims (1)

[Claims] 1 1 to 2 artificial inorganic fibers per 100 parts by weight of cement
0 parts by weight, 10 to 50 parts by weight of hard granules that have passed through 30 meshes and contain silicate minerals or carbonate minerals, and a monomer having a heavy unsaturated group. When blending 0.2 to 20 parts by weight in terms of resin content to obtain a cement composition, artificial inorganic fibers and hard granules are thoroughly stirred and mixed in advance and added to the cement together with the above synthetic resin emulsion. A method for producing a cement composition characterized by mixing.