JPH10156813A - Manufacture of inorganic cement board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent peeling by the adhesive effect of a fibrous clay substance between green sheets, when they are laminated, by spraying the substance on the surface of the green sheet before lamination. SOLUTION: A fibrous clay material is sprayed on the surface of a green sheet before lamination. Thus enough interlayer contact strength is afforded to the green sheet to improve a take-up property by a making roll and to restrain the generation of delamination. The amount of the substance to be added is preferably 0.1-10wt.% of the solid content of the sheet. If the value is below the range, an enough effect can hardly obtained, while when the value exceeds the range, the layer of the substance is formed between the laminated sheets to deteriorate the interlayer contact strength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a ceramic exterior material,
The present invention relates to a method for producing an inorganic cement board used as a building material such as a tile material or an external structural member.

[0002]

2. Description of the Related Art A green sheet is formed by forming an aqueous slurry containing cement, aggregate, and reinforcing fibers as main components.
In the method for producing an inorganic cement board, which includes a step of press-molding a green laminated sheet formed by laminating a plurality of green sheets with a making roll or the like, a sufficient interlayer is required because the green laminated sheet tends to peel off between the layers. Adhesion strength is required. Conventional inorganic cement boards that used asbestos as a reinforcing fiber provided sufficient interlayer adhesion strength, but in recent years, the mainstream has been to use organic fibers such as pulp and resin fibers instead of asbestos that is harmful to the human body. In the green sheet using the organic fiber, sufficient interlayer adhesion strength was not obtained. For this reason, it causes troubles such as poor winding around the making roll and delamination during transfer. Further, the obtained inorganic cement board was liable to cause cracks between layers due to frost damage.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and in adopting a manufacturing method of laminating and molding a plurality of green sheets, an inorganic material having improved interlayer adhesion of the green sheets is used. A method for producing a cement board is provided.

[0004]

According to a first aspect of the present invention, there is provided a method for manufacturing an inorganic cement board, comprising forming an aqueous slurry containing cement, aggregate and reinforcing fibers as main components to form a green sheet; A method for producing an inorganic cement board including a step of press-molding a green laminated sheet in which a plurality of green sheets are laminated, wherein a fibrous clay material is sprayed on the surface of the green sheet before lamination.

[0005] A method of manufacturing an inorganic cement board according to a second aspect is the method of manufacturing an inorganic cement board according to the first aspect, wherein the green sheets are laminated by a making roll.

According to a third aspect of the present invention, there is provided a method of manufacturing an inorganic cement board according to the first or second aspect, wherein the amount of the fibrous clay material added is based on the solid content of the green sheet. The method for producing an inorganic cement board according to claim 1, wherein the content is in a range of 0.1 to 10% by weight.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

In the method for producing an inorganic cement board according to the present invention, a green sheet is formed by forming an aqueous slurry containing cement, aggregate, and reinforcing fibers as main components, and forming a green sheet. Including a step of press molding, wherein in this step,
It is characterized in that a fibrous clay material is sprayed on the surface of a green sheet before lamination.

First, the aqueous slurry will be described. The aqueous slurry is prepared by putting raw materials mainly composed of cement, aggregate, and reinforcing fibers into a large amount of water and mixing with stirring. The solid content concentration of the aqueous slurry is not particularly limited, and may be appropriately adjusted so as to have optimal fluidity or the like according to the material composition.For example, when pulp is used as a reinforcing fiber, it is usually used. It is customary to prepare up to 20% by weight.

The cement used as a raw material is not particularly limited, and generally used cements such as Portland cement and blast furnace cement can be used. The aggregate is not particularly limited and may be selected according to the intended use of the inorganic cement plate.For example, generally used mineral aggregates, inorganic aggregates, and organic aggregates System-based aggregates can be used, and specific examples include silica powder, fly ash, silica sand, microsilica, gravel, perlite, vermiculite, bentonite, wollastonite, and glass balloon.
The mixing ratio of the cement and the aggregate is not particularly limited, and may be appropriately determined according to the use of the inorganic cement plate. The reinforcing fiber is not particularly limited, and examples thereof include pulp fiber, organic fiber such as polyethylene, polypropylene, and vinylon, mineral fiber such as asbestos, glass fiber, carbon fiber, and metal fiber. In particular, when pulp or organic fiber is used, sufficient interlayer adhesion cannot be obtained, so that the improvement effect is large.

Next, a method for manufacturing a green sheet will be described. The prepared aqueous slurry is formed on a filter cloth such as a felt and formed into a sheet to obtain a green sheet. The green sheet is laminated on a plurality of layers by transferring the green sheet to a rotating making roll to obtain a green laminated sheet. At this time, in the present invention, the fibrous clay material is sprayed on the surface of the green sheet before lamination, thereby giving a sufficient interlayer adhesion strength to the green sheet, improving the winding property with a making roll, and In such a manner that peeling of the film hardly occurs. The timing at which the fibrous clay material is sprayed on the surface is not particularly limited as long as it is before laminating a single-layer green sheet, and may be, for example, immediately before winding with a making roll, and forming an aqueous slurry on felt. It may be during the formation of the cake being raised, or
It may be on an aqueous slurry immediately before being fed onto the felt and before cake formation.

Here, the above-mentioned fibrous clay material is a material having a very large specific surface area and a high adsorptivity.
For example, attapulgite, sepiolite and the like are exemplified. The fibrous clay material exerts an adhesive effect between the layers of the laminated green sheets by its adsorption action to prevent peeling. The amount of the fibrous clay material to be added is preferably in the range of 0.1 to 10% by weight based on the solid content of the green sheet. That is, if the amount is less than this range, a sufficient effect cannot be obtained. This is because, if the ratio exceeds the above, a layer of the fibrous clay material is formed between the layers of the laminated green sheets, and the interlayer adhesion is conversely reduced.

The green laminate sheet obtained as described above can be adjusted to a desired thickness by press molding or the like, and can be given a desired pattern on the surface, and further cured and cured to obtain an inorganic cement board. Can be
The curing method at this time is not particularly limited, and may be, for example, a method generally performed such as wet heat curing or autoclave curing. The inorganic cement board thus obtained is less likely to crack between layers and has improved frost damage resistance.

[0014]

EXAMPLES Hereinafter, the present invention has been concretely carried out as examples, and the effects thereof have been confirmed.

Example 1 Portland cement and silica powder were mixed at a ratio of 4: 3, and a large amount of water was added to a raw material obtained by adding pulp to 6% by weight, and a solid content of about 10% by weight was added. % Aqueous slurry was prepared. This was subjected to papermaking by a small test papermaking machine. This small test paper machine has a configuration in which a flow box for supplying an aqueous slurry is installed above an automatically conveyed felt, and a suction box for vacuum dehydration is installed below the felt. And
The aqueous slurry was poured out of the flow box onto the conveyed felt, and immediately thereafter, the sepiolite slurry was sprayed on the aqueous slurry, and further, dehydration was performed under reduced pressure using a suction box to produce a green sheet. This green sheet was transferred to a felt or a making roll and wound up, and a plurality of layers were laminated to evaluate the windability at that time. At this time, the addition amount of sepiolite was adjusted so that the amount based on the solid content of the green sheet was changed between 0.1 and 10% by weight.

Example 2 A green sheet was prepared in the same manner as in Example 1 except that the timing of spraying the sepiolite slurry was changed to a cake forming process in which the aqueous slurry on the felt was dewatered under reduced pressure by a suction box. Transfer this green sheet to a felt or making roll and wind it up.
A plurality of layers were laminated and the winding property at that time was evaluated.

Example 1 Example 1 was repeated except that the timing of spraying the sepiolite slurry was changed on the green sheet after the cake was formed.
This green sheet was transferred to a felt or a making roll and wound up in the same manner as described above, and a plurality of layers were laminated to evaluate the winding property.

Example 4 A green sheet was prepared in the same manner as in Example 1 except that the sepiolite slurry was changed to attapulgite.
This green sheet was transferred to a felt or a making roll and wound up, and a plurality of layers were laminated to evaluate the windability at that time.

Example 5 A green sheet was prepared in the same manner as in Example 2 except that the sepiolite slurry was changed to attapulgite.
This green sheet was transferred to a felt or a making roll and wound up, and a plurality of layers were laminated to evaluate the windability at that time.

Example 6 A green sheet was prepared in the same manner as in Example 3, except that the sepiolite slurry was changed to attapulgite.
This green sheet was transferred to a felt or a making roll and wound up, and a plurality of layers were laminated to evaluate the windability at that time.

Comparative Example 1 A green sheet was prepared in the same manner as in Example 1 except that the fibrous clay material was not sprayed, and the green sheet was transferred to a felt or a making roll and wound up, and a plurality of layers were laminated. Then, the winding property at that time was evaluated.

The evaluation results of Examples 1 to 6 and Comparative Example 1 are shown in Table 1.

[0023]

[Table 1]

As shown in Table 1, it was found that the sprinkling of the fibrous clay materials sepiolite and attapulgite improved the winding property of the making roll. The effect is exhibited with a small amount when sprayed after the cake is formed. However, when the amount is excessively added, a sepiolite or attapulgite layer is formed, and conversely, the interlayer adhesion strength is reduced. On the other hand, when sprayed on the slurry surface before cake formation or on the cake formation process, a certain amount of addition is required for the effect to appear, but unless the addition amount is excessively large, a layer of sepiolite or attapulgite is formed between the layers. It was not formed.

[0025]

As described above, according to the method for manufacturing an inorganic cement board of the present invention, when a green sheet is laminated by spraying a fibrous clay material on the green sheet before lamination. Since the fibrous clay material has an adhesive effect between the layers and prevents peeling, the interlayer adhesion of the green sheet is improved. That is, the winding property when the green sheet is wound up by the making roll is improved, and cracks and the like hardly occur between the layers even in the inorganic cement board.

Claims (3)

[Claims] A green sheet is formed by forming an aqueous slurry containing cement, aggregate, and reinforcing fibers as main components.
A method for producing an inorganic cement board, comprising a step of press-molding a green laminated sheet obtained by laminating a plurality of green sheets, wherein a fibrous clay material is surface-spread on the green sheet before lamination. . 2. The method for producing an inorganic cement board according to claim 1, wherein said green sheets are laminated by a making roll. 3. The inorganic cement board according to claim 1, wherein the amount of the fibrous clay material is in the range of 0.1 to 10% by weight based on the solid content of the green sheet. Manufacturing method.