JPS6046068B2 - inorganic board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inorganic board, and its object is to provide an inorganic board that is lightweight, has a high specific strength (strength/density), and is nonflammable.

Fiber plate-like bodies made of inorganic fibers as a main raw material have been provided in the past, but they generally have a limited specific strength.

In other words, as the density is increased, the absolute strength increases, but the specific strength does not increase, and if the amount of binder is increased, the nonflammability of the inorganic fiber board will be lost, so the The specific strength was not what I expected. Furthermore, even if it is possible to increase the absolute temperature by increasing the density, pressing the plate-like material will cause the inorganic fibers to break or buckle at a certain limit, so it is difficult to increase the absolute strength. I've reached my limit. The present invention aims to overcome these conventional drawbacks and will be described in detail below.

The present invention uses a combination of two types of small hollow spheres made of inorganic fibers L-7, Mountain Luna I, and IY, and in particular, micro hollow spheres with greatly different particle sizes, and a small amount of binder is added thereto. It is characterized by obtaining a plate-shaped body by heating and pressing in a dry state. Here, a glass balloon or a glass balloon is used as the micro hollow sphere, and examples of the binder include phenol resin, resorcinol resin, area resin, area-melamine cocondensation resin, and the like. Here, the particle size of the micro hollow spheres is preferably 600 μm or less, and within this range, the particle size distribution has two peaks. In this case, it is desirable that the width of the particle size distribution for each of the two peaks be as narrow and sharp as possible, and if the average particle size of the large diameter micro hollow spheres is D and the average particle size of the small diameter micro hollow spheres is d, then
The ratio of the average particle diameters of the two peaks [d/D] is preferably 1/2 to 1/1 week. 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 0. 2/1 is possible in a wide range. For example, when using micro hollow spheres with a density of 0.3 Da/cTIl, the mass mixing ratio (fiber mass/hollow sphere mass) is in the range of 20/1 to 0.8/1, preferably 1.
The range of 5/1 to 2/1 is good, and when using micro hollow spheres with a density of O, 7y/d, the mass mixing ratio is 517/1.
The range is preferably from 10/1 to 1/1, preferably from 10/1 to 1/1. Although the binder is not particularly limited, when a phenol resin is used, the fiberboard has high elasticity and excellent strength. The mixing ratio of the binder is the mass ratio (
Binder mass/fiber + hollow sphere mass) 2/10
Approximately 0 to 15/1 (1) is appropriate, but it is necessary to adjust the amount of binder mixed depending on the mixing ratio of inorganic fibers and inorganic minute hollow spheres, as well as the fiber diameter and hollow sphere diameter. . In producing the inorganic fiberboard according to the present invention, inorganic long fibers or short fibers (wool) having a fiber diameter of about 3 to 20 μm and the two kinds of inorganic micro hollow spheres having different particle diameters are used within the above range. Mix and spray or scatter a water-soluble or powdered resin binder in an amount within the above range.

If a water-soluble binder is used here, the binder may be applied to the fibers and hollow spheres by spraying them separately in advance and then mixing them 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.
As mentioned above, the present invention has inorganic fibers mixed with inorganic microscopic hollow spheres and bonded with a binder.
It can be easily obtained using a dry process method, and high pressure can be easily applied during compression molding! becomes possible.

In other words, in the case of conventional inorganic fiberboards, if the load pressure during molding is increased, the fibers break or buckle, so there is a limit to the load pressure itself, but in the case of the present invention, the By providing a two-peak particle size distribution, the filling state of the hollow spheres, that is, the contact area between the hollow spheres increases, and as a result, the pressure that can be applied during hot pressing can be increased, so the This makes it possible to obtain a plate-like body with great strength. In addition to this, both of the two types of fillers are hollow spheres, and the hollow spheres themselves have low density, so even if relatively high pressure is applied during molding, the density of the fiberboard will increase unnecessarily. It has the advantage of greatly improving strength without sacrificing lightness.
In addition, since the two types of inorganic micro hollow spheres with different diameters are the glass balloon and the glass balloon, the above features are further enhanced by the low cost of the glass balloon and the high pressure resistance of the glass balloon. be able to. That is, by using a glass balloon, the load pressure during molding can be further increased than when only a glass balloon is used. The present invention will be specifically described below based on examples.

〔Example〕

Rock wool 40 with a fiber diameter of 4 to 12μ (average diameter 7μ)
Wt%, the diameter of the hollow sphere is 150 to 400μ (average diameter 21
0p) Shirasu Balloon 38Wt. %, glass balloon 14W with a hollow sphere diameter of 20 to 61μ (average diameter 44μ)
t% was mixed, and 8 wt% of phenolic resin was added thereto by spraying.

The material was put into a frame and formed by applying a pressure of 30 kg/d using a hot platen heated to 180'C. The density of the plate thus obtained was 0.40, and the bending strength was measured to be 36k9/c.

Claims (1)

[Claims] 1. It is made by bonding inorganic fibers and two types of inorganic micro hollow spheres with different diameters with a binder, and the two types of inorganic micro hollow spheres with different diameters are a glass balloon and a glass balloon. Characteristic inorganic board.