JPS6112873B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an inorganic fiberboard,
The purpose is to provide an inorganic fiberboard that is lightweight and strong, and that can be easily and inexpensively obtained by a dry manufacturing method. Fibreboard, which is made by bonding inorganic fibers with binders, has been commercially available as a building material and is in practical use.There are two methods for producing it: wet and dry.The wet method involves a waste liquid treatment process. , a drying process is required, which increases costs, and in the dry method, high pressure cannot be applied during molding due to fiber breakage and buckling, resulting in insufficient adhesion and the need to increase the amount of binder. There were drawbacks such as the occurrence of The present invention aims to overcome these conventional drawbacks and will be described in detail below. The present invention blends inorganic micro hollow spheres into inorganic fibers in a desired ratio,
It is molded into a plate shape using a binder. Examples of inorganic fibers include long glass fibers, glass wool, rock wool, etc., and examples of inorganic microscopic hollow spheres include glass or ceramic microscopic hollow spheres. Further, the binder includes water-soluble or powdered phenol resin, resorcinol resin, urea resin, urea melamine cocondensation resin, etc., but other appropriate binders can be used without particular limitation. Furthermore, the mixing ratio of inorganic fibers and inorganic microscopic hollow spheres varies greatly depending on the density of the microscopic hollow spheres used, but generally the mass mixing ratio (fiber mass/hollow sphere mass) is 20/1 to 20/1.
A wide range of up to 0.2/1 is possible. For example, the density
When using micro hollow spheres of 0.3 g/ ^cm3 , the mass mixing ratio (fiber mass/hollow sphere mass) is 20/1 ~
The mass mixing ratio is preferably in the range of 0.8/1, preferably in the range of 15/1 to 2/1, and when using micro hollow spheres with a density of 0.7 g/cm ³ , the mass mixing ratio is in the range of 17/1 to 0.2/1. It is preferably in the range of 10/1 to 1/1. Although the binder is not particularly limited, when a phenolic resin is used, the fiberboard has high elasticity and excellent strength. The mixing ratio of the binder is approximately 2/100 to 15/100 in terms of mass ratio (binder mass/fiber + hollow sphere mass), but the mixing ratio of inorganic fibers and inorganic fine hollow spheres, and even the fiber diameter It is also necessary to adjust the amount of binder mixed depending on the diameter of the hollow sphere. In producing the inorganic fiberboard according to the present invention, inorganic long fibers or short fibers (wool) with a fiber diameter of about 3 to 20 μm and spherical diameter of 5 to 600 μm, preferably
Inorganic minute hollow spheres of about 10 to 250 microns are mixed in the above range, and a water-soluble or powdered resin binder is sprayed or dispersed in the above range. If you use a water-soluble binder here,
The binder may be applied to the fibers and the hollow spheres by spraying them separately in advance and then mixed in a desired ratio. Then, the mixture is put into a frame having a desired area and thickness, and compression molded by applying heat and pressure to obtain a fiberboard. Here, the ratio of inorganic fibers and the ratio of micro hollow spheres in the surface layer and inner layer of the inorganic fiberboard are changed, and the ratio of inorganic fibers in the surface layer is higher than that in the inner layer, and the ratio of inorganic fibers in the inner layer is higher than that in the surface layer. It contains a large proportion of micro hollow spheres.
Therefore, in manufacturing the above-mentioned fiberboard, two types of compound materials with different blending ratios of inorganic fibers and micro hollow spheres are prepared, and a binder is mixed with each compound material by spraying to form a surface layer. The material for the center layer and the material for the center layer are prepared, and the material for the center layer is sandwiched with the materials for both surface layers and then molded. Alternatively, an aqueous solution of a water-soluble binder is separately sprayed on the fibers and the hollow spheres in advance to adhere the binder, and the materials are mixed in different proportions to prepare the surface layer material and the center layer material. Also good. As described above, the present invention is made by blending inorganic microscopic hollow spheres with inorganic fibers and bonding them together with a binder, so it can be easily obtained using a dry method, and it can be easily obtained at high pressure during compression molding. It becomes possible to apply. In other words, in the case of conventional inorganic fiberboards, in order to avoid fiber breakage and buckling, the load pressure during molding can only be a few kg/ ^cm2 at most, so there are few contact areas between the fibers and the binder does not flow. Compared to the fiberboard of the present invention, the fiberboard is bonded and shaped with far fewer bonding points, and therefore has its own limitations in strength. In this case, even if molding is carried out in a low load pressure range that avoids fiber breakage and buckling, the density increases as the pressure increases, so there is no merit in terms of specific strength. However, in the case of the present invention, since inorganic minute hollow spheres are mixed, the load pressure during molding can be reduced to 10~10.
It is possible to raise the weight up to about 30Kg/cm ² smoothly and without difficulty, and the contact points between the fibers and the hollow spheres are increased, and the binder also flows under pressure, making it possible to bond extremely efficiently with a small amount. The fiberboard has much higher strength than conventional fiberboard. In addition, since the hollow sphere itself has a low density, even if relatively high pressure is applied during molding, the density of the fiberboard will not increase unnecessarily, allowing for greater strength without sacrificing lightness. There are advantages that can be improved. In addition, the surface layer has a higher proportion of inorganic fibers than the inner layer, and the inner layer has a higher proportion of micro hollow spheres than the surface layer, so the surface layer is made of inorganic fibers like conventional fiberboards. It contains a high proportion of hollow spheres, giving it a beautiful surface and is highly cosmetic.The center contains a large proportion of hollow spheres, making it lightweight, and has the advantage of being highly insulating. It has the advantage of having a sandwich structure between the surface layer and the inner layer, so it is not inferior in strength. The present invention will be specifically described below based on comparative examples and examples. [Comparative Example 1] Rock wool with a fiber diameter of 5 to 11μ and an average particle diameter of
Glass balloons with a diameter of 60 μ (10 to 200 μ) and a density of 0.33 g/cm ³ are mixed at the mixing ratio shown in Table 1 below, and a water-soluble phenol resin solution is added to the mass ratio [resin solid mass/(rock wool + glass balloon)]. )mass〕
It was mixed uniformly by spraying at 8/100.

【table】

[Comparative example 2]

The same rock wool and glass balloon as in Comparative Example 1 were used, and the mixing ratio of both was the same as in Sample B.
A material was prepared in which a urea melamine cocondensation resin was used as a binder and the amount of the mixed resin was 8/100 in terms of mass ratio. Next, a fiberboard was molded under the same molding conditions as in Comparative Example 1, and the bending strength was measured. Although the strength was slightly lower than that of sample B, it was much lower than that of sample D (when glass balloons were not mixed). It was made of reinforced fiberboard. [Example] The same rock wool and glass balloon as in Comparative Example 1 were used, and the phenol resin solution was uniformly sprayed in the amount shown in Table 2 to two types of compounded materials whose mixing ratios were as shown in Table 2. A material for the surface layer and a material for the center layer were prepared by mixing the materials.

[Front] Using these materials, use the surface layer material so that both the front and back layers are 0.3 mm, and the center layer is 0.4 mm.
Use the center layer material so that the thickness is 200℃, molding temperature 200℃, molding time 5 minutes, molding pressure 9-15Kg/cm ²
Sand German trench fiberboards with dimensions of 300 ^W × 600 ^L × 10 ^H were obtained in the range of . This fiberboard is designated as E sample. However, a sample was taken from this sample E, and the bending strength was measured, and the results are shown in FIG. 2 in comparison with the above samples B and D. Although the strength of sample E was slightly lower than that of sample B, the surface was very beautiful.

[Brief explanation of the drawing]

Figure 1 is a characteristic diagram showing the relationship between density and bending strength of each sample in Comparative Example 1 of the present invention, and Figure 2 is a characteristic diagram showing the relationship between density and bending strength of each sample in the same example. FIG.

Claims (1)

[Claims] 1. Inorganic fibers and inorganic minute hollow spheres are 20/20/
They are blended at a ratio of 1 to 0.2/1 and bonded with a binder, with the surface layer containing a higher proportion of inorganic fibers than the inner layer, and the inner layer containing a higher proportion of micro hollow spheres than the surface layer. An inorganic fiberboard comprising: 2. The inorganic fiberboard according to claim 1, characterized in that a phenolic resin is used as the binder. 3. The inorganic fiberboard according to claim 1 or 2, characterized in that the board is made by compression molding.