JPS59174552A - Inorganic hardened 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 [Technical Field] The present invention relates to an inorganic hardened fiber containing reinforcing polyvinyl alcohol fiber (also referred to as vinylon, hereinafter abbreviated as PVA fiber) that has excellent adhesion to an inorganic binder such as cement. Regarding the body.

[Background technology]

Conventionally, when building materials and products are made using hydraulic raw materials (inorganic binders) such as cement, gypsum, and calcium silicate, asbestos has been typically used as a reinforcing material for fibers and the like. In recent years, inorganic fibers such as steel fibers, glass fibers, and carbon fibers have been used as substitutes for asbestos due to problems such as the negative effects of asbestos on the human body from the standpoint of pollution and hygiene, and the difficulty in obtaining resources because it is a natural product. The use of organic fibers such as J-polypropylene, polyamide, and PVA, alone or in combination, as reinforcing fibers is being considered.

All of the above-mentioned alternative reinforcing fibers have advantages and disadvantages, and it cannot be said that the technology to completely replace asbestos has been completed. Among these, PVA' fibers have hydroxyl groups at the ends, so they are compatible with the matrix, and are superior in terms of reinforcing effect and economical efficiency. However, by simply mixing PVA fibers with cement as in the past, the high Young's modulus of PVA fibers cannot be fully utilized. In other words, the adhesion between cement and PVA&& fiber is still not sufficient.
It can be inferred that by improving this point, materials and products with even better performance can be obtained. In view of these points, a patent has been disclosed in which an attempt was made to improve the adhesion of cement by providing recesses in PVA fibers (Japanese Unexamined Patent Publication No. 1983-1999).
-149374, JP-A-56-140113. Japanese Patent Application Publication No. 5
6125270, JP-A-56-140112, etc.).

However, all of the disclosed techniques are based on PVAI.
This is a Jli fiber with a recessed part, and there is no part that is thicker than the original fiber diameter, and the diameter of the recessed part is smaller than the original fiber diameter. Therefore, there is a problem that the tensile strength of the fibers is reduced, and the effect is not so good from the viewpoint of increasing the adhesive strength with cement. That is, once pulled out from the matrix, there was a drawback that the PVA fibers easily pulled out because there was no hooking part.

[Purpose of the invention]

This invention was made in view of the above circumstances, and an object thereof is to provide an inorganic cured product with excellent strength by improving the adhesive strength with a matrix of PVA fibers as reinforcing fibers. [Disclosure] As a result of intensive study on the shape and structure of reinforcing fibers when reinforcing an inorganic cured product, the inventors found that if PVA fibers with enlarged width or diameter portions are used here and there, the above-mentioned Confirm that the purpose can be achieved,
This invention was completed.

Therefore, the gist of the present invention is an inorganic cured product characterized in that PVA fibers having enlarged width or diameter portions are used here and there as reinforcing fibers. This will be explained in detail below.

As raw materials for producing the inorganic cured product according to the present invention, an inorganic binder and reinforcing fibers are essential.

The inorganic binder used in this invention refers to a hydraulic substance in a broad sense, and refers to cement 11 in a narrow sense. That is, hydraulic substances include cements, slags, gypsums, limes, magnesium carbonates, and the like. Cement refers to ordinary Portland cement, alumina cement, early strength cement, jet cement, blast furnace cement, fly ash cement, etc. Further, as the reinforcing fibers, hydrophilic PVA fibers are used. PVA fibers are spun by a wet spinning method, a dry spinning method, etc., and are shaped during heat treatment so that the width or diameter becomes larger in some places.

Figure 1 shows PVA used in the inorganic cured body according to this invention.
FIG. 2 is a side view of FIG. 1 viewed from the arrow A side, and FIG. 3 is a side view of FIG. 1 viewed from the arrow B side. As seen in these figures, PVA
The fiber 1 has portions 2 which are widened here and there in the fiber axis direction. These portions 2 have increased widths as shown in FIG. 2 when viewed from at least one side. In other words, it is normal for the fibers to be twisted in the part 2 where the PVA fibers are pressed and widened by shaping during heating. This is because it looks flat as shown in Figure 3. However, it is not limited to what is shown in this model diagram, and any diameter can be used even if it is viewed from any angle. Figures 4 and 5
The figures show microscopic photographs of PVA fibers, with FIG. 4 being a side view before molding, and FIG. 5 being a side view after heat treatment molding. As can be seen in FIG. 5, after the heat treatment molding, portions 2 with large widths or diameters are formed here and there. The fiber diameter of part 2 (tl) and the original fiber diameter (t2
) has the relationship tl > tt. The portions 2 do not need to be regularly arranged in the fiber axis direction. The diameter of the portion 2 is preferably about 2 to 3 times the original fiber diameter (t2), but is not particularly limited to this. As for the number of parts, preferably one part with a length of about 20 to 100 microns is provided for each fiber length of 50 to 200 microns. This portion functions to improve adhesion at the interface with the cement matrix. Therefore, a cured product obtained by mixing PVA fibers having such portions into a cement matrix has significantly increased strength (flexural strength, impact strength, etc.) compared to the use of ordinary PVA fibers. Although the mechanism of this strength development is not yet clear, in the case of this invention, PVA
This is thought to be because the surface area of the fibers could be increased without decreasing their cross-sectional area, which increased the area of adhesion with the cement matrix and made it difficult for the fibers to come off in some areas. Since the cross-sectional area does not decrease at all, there is no decrease in the strength of the fiber itself. The content of the PVA fiber having the portion 2 is preferably 0.5 to 5% by weight based on the total weight of the raw material solids. If it is less than 0.5% by weight, the reinforcing effect will not be significant, and if it exceeds 5% by weight, it will be difficult to disperse the fibers, which may conversely cause a decrease in strength. The inorganic cured product according to the present invention may contain other additives as necessary, such as inorganic fillers (clay-based, silica powder, calcium carbonate powder, etc.), fibers (rock wool, steel fiber, etc.), and flocculants. , *Resin substances such as water agents can be added.

〔Effect of the invention〕

The inorganic cured body according to the present invention is made of PVA having parts with increased width or diameter in some places as reinforcing fibers.
Since it contains fibers, it is an inorganic cured product with significantly increased strength (flexural strength, impact strength, etc.) compared to those using ordinary PVA@fibers as reinforcing fibers.

Examples will be described below along with comparative examples [Examples 1 to 3] First, as reinforcing fibers, PVA#a fibers obtained by a normal wet spinning method were subjected to the conditions shown in Table 1. Therefore, a mold was prepared while heat-treating, and a portion 2 as shown in FIG. 5 was provided.

[Comparative Example 1] PV as shown in Fig. 4 without heat treatment was used as reinforcing fiber.
A fiber was prepared.

[Comparative Example 2] As reinforcing fibers, PVAt8 fibers with concave portions formed on the surface were prepared using a method similar to JP-A-56-140113.

These Examples 1 to 3. Using the PVA fibers prepared in Comparative Examples 1 and 2, a cement slurry was made with the mixing ratio shown in Table 1, and honeynic papermaking (round net papermaking) was carried out under the papermaking conditions also shown in Table 1. ,moreover,
Curing was performed under the conditions shown in Table 1 to obtain a flat inorganic cured product with a thickness of 7I. Table 2 shows the physical properties of each inorganic cured product.

(Margin below) Table 1 ■ Table 2 Examples 1 to 3 have better bending strength than Comparative Examples 1 to 2.

It was an inorganic cured product with excellent impact strength and glabella adhesion strength.

[Brief explanation of drawings]

Figure 1 shows PVA used in the inorganic cured body according to this invention.
Figure 2 is a side view of Figure 1 viewed from the arrow A side, Figure 3 is a side view of Figure 1 viewed from the arrow B side, Figures 4 and 5 are a perspective view of the fiber morphology model. The figures show microscopic photographs of the PV Yaori fiber, in which Figure 4 is a side view before molding, and Figure 5 is a side view after heat treatment molding. 1... PVA fiber 2... Partial agent with increased width or diameter Patent attorney Takehiko Matsumoto Figure 2 Figure 3

Claims (3)

[Claims] (1) An inorganic cured product characterized by using polyvinyl alcohol fibers having enlarged width or diameter portions here and there as reinforcing fibers. (2) The inorganic cured product according to claim 1, wherein the polyvinyl alcohol fiber is made thicker by being crushed in some places. (3) The inorganic cured product according to claim 1 or 2, wherein the polyvinyl alcohol fiber is contained in an amount of 0.5 to 5% by weight based on the solid weight of the raw material.