JPS6054265B2 - inorganic molding material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inorganic molding material with excellent heat resistance and water resistance.

Existing plastic molding materials have excellent performance and are widely used, but although considerable improvements have been made in terms of heat resistance and nonflammability, they are still far from satisfactory.
In particular, it is difficult to meet the recent problem of gas generated during fires and the demand for heat resistance for safety reasons.

On the other hand, ceramics, glass, cement, silicates, phosphates, etc. are known as inorganic molding materials or molded bodies from the viewpoint of heat resistance and nonflammability, but ceramics shrink due to the need for firing at high temperatures. There are disadvantages such as the large size and poor dimensional accuracy, and the inability to assemble the metal at the same time as molding.

Products using cement, silicates, and phosphates have poor water resistance, so they have the disadvantage that their insulation properties are significantly reduced in high humidity. Furthermore, since glass must be molded at a high temperature of 700 to 800°C, there is a problem with the heat resistance of the mold. For a long time, there is a molding material or molded object called "mica rex" which is made by using lead borate-based low melting point glass as a binder and blending it with mica powder, and which can be molded at 450 to 600 degrees Celsius. It is not preferable to use it from the viewpoint of toxicity. The present invention has been made for the purpose of improving the above-mentioned drawbacks.

That is, the present invention provides a heat-resistant and water-resistant molding material made by using low-melting point glass as a binder, which does not contain toxic substances such as lead, and incorporating an inorganic filler therein. According to the present invention, the J molding material has the characteristic that it is nonflammable because it is mainly composed of inorganic substances. The present invention will be explained in further detail below.
The low melting point glass binder of the present invention has a composition in which the weight of the bean paste excluding water is at least % (hereinafter abbreviated as %) or more.

As O; 7.5-14%, as ZnO 20-50
%,B. 0-35% as 03, 35-35% as P2O5
65% glass composition.

The reason why each numerical limitation was made in the above composition is as follows.

When Na2O is less than 7.5%, the softening temperature of the glass is high;
Therefore, the molding temperature also increases.

If it exceeds 14%, water resistance tends to decrease.

If the ZrlO content is less than 20%, the water resistance decreases significantly, and 50%
%, crystallization tends to occur and the softening temperature increases.
B. O3 tends to lower the softening temperature and make it easier to flow, but if it exceeds 35%, water resistance decreases. P2O5 is 3
If it is less than 5%, the softening temperature becomes high, which is not preferable from the viewpoint of moldability. When it exceeds 65%, water resistance deteriorates significantly.

As a raw material for obtaining the glass binder having the above composition, any compound can be used as long as it contains the elements forming the above oxide and becomes the oxide in the glass binder formulation when fired (melted). .

For example, soda carbonate, sodium phosphate (orthophosphate, condensed phosphate), sodium nitrate, sodium borate (including metaborate), zinc oxide, zinc hydroxide, zinc carbonate, (orthophosphate, condensed phosphate), Acid salts) Zinc borate, phosphoric acid, ammonium phosphate, boric acid, etc. are used. In order to obtain the desired glass binder using each of the above raw materials, the raw materials are blended in a predetermined ratio and thoroughly pulverized and mixed at room temperature and heated if necessary.

This mixture is melted at 800-1300°C for 1-4 hours. Stir in between if necessary. When using carbonate, ammonium salt, or water-containing raw materials as raw materials, it is better to pre-calcine them at 150-500℃ for 1-3 hours after mixing the raw materials to remove volatiles, and then melt them in a crucible! It is safe and convenient, as no boiling over occurs. The molten glass is thrown into water or poured onto a thick iron plate to cool it quickly. The resulting glass is pulverized using a suitable device such as a ball mill or a vibratory mill. The finer the particle size, the more convenient it is to mix with the filler. Although not limited to this, it is preferable to finely pulverize to 150 μm or less. The glass binder thus obtained has a softening temperature of 290-490°C. The inorganic fillers used in the present invention are similar to those used in general plastic molding materials, such as calcium carbonate, alumina, quartz, silica, silica sand, diatomaceous earth, asbestos, glass fiber, glass, etc. Powder, glass balloon,
Whitebait ●Natural products such as balloons, mica, talc, clay, etc.
Compounds, particles, plates, fibers, hollow spheres, and rods can be used, and these may be used alone or in combination of two or more. The amount of these inorganic fillers used is 0.1 to 2.5 times (by weight) the amount of the glass binder. 0.
Even if the amount is less than 1 times the amount, it can be sufficiently molded and the desired properties can be obtained in terms of water resistance and heat resistance, but it is not preferred from a practical point of view because it is brittle in terms of strength.

If the amount exceeds 2 hours, flow becomes poor and a dense molded product cannot be obtained, which is not practical in terms of water resistance and strength.

The glass binder and filler are mixed using suitable equipment such as a ball mill or a mill. The molding material thus obtained is heated to a temperature equal to or higher than the softening temperature of the glass binder and then pressure molded.

The molding method may be compression molding, transfer molding, or injection molding. Molding conditions vary depending on the molding method, shape of the molded product, etc., but in the case of compression molding, for example, 350-500℃, 100-1000k9/Cl
This is a condition of tll to 1 minute. The molded product has good water resistance, heat resistance of 300° C. or more, and good insulation and mechanical strength.

It is also possible to incorporate metal during molding. Since it is mainly composed of inorganic substances, it is natural that it is nonflammable. Therefore, the inorganic molding material according to the present invention can be used as a structural material or an insulating material that requires heat resistance and nonflammability. Examples are shown below.

Example 1 Zinc heavy phosphate [Zn(H2PO4)2.2H20] 33
7g Soda carbonate [Na2cO3] 54.7g 1 Zinc oxide [ZnO] 38.1g were mixed, pre-fired at 350℃ for 1 hour, then melted in an electric furnace at 1100-1200℃ for 1 hour, and then placed on an iron plate. I rinsed it off and cooled it down quickly.

After cooling to room temperature, it was finely pulverized to a 100-mesh powder. The softening temperature of the obtained glass was 340°C. 60g of this glass binder powder and 40g of alumina were mixed in a vibration mill.
The desired molding material was obtained by powder mixing. This molding material 1
Put 6g into a 50WL/7nΦ disc mold, and
Molded under the conditions of 0'C9OOk9/Cltl for 5 minutes to a thickness of 2
．． 40771. /Trl, was obtained.

The specific gravity was 3.37, the boiling water absorption was 0%, there was no change in appearance after boiling, and there was no change at all even after heat treatment at 300°C for 4 m. Insulation resistance is 1014Ω under normal conditions and 1012Ω after boiling.
It was hot.

Example 2 60 g of the glass binder obtained in Example 1 and silica powder (325
A molding material was obtained by mixing 3 powders of 40 g of all mesh products in a vibrating mill.

A disk having a diameter of 50 n1/mΦ was molded under the same conditions as in Example 1.

Thickness 280rn/m1 Specific gravity 2.87, boiling water absorption rate 0.0
1%, there was no change in appearance after boiling, and no change occurred after heat treatment at 300°C, Northern Time. Insulation resistance is normally 1014Ω,
It was 1012Ω after boiling. Example 3 A molding material obtained by mixing 60 g of the glass binder of Example 1 and 40 g of mica powder in a vibration mill was similarly molded to a thickness of 2.807 TI. /TrLl A disk with a specific gravity of 2.88 was obtained.

The boiling water absorption rate was 0.6%, and there was no change after boiling and after heat treatment at 300° C., Northern Time. Insulation resistance is normally 101
4Ω, and after boiling it was 1010Ω. Example 4 Zinc heavy phosphate [Zn(H2PO4)2.2H20] 37
9g1 anhydrous borax 28.7g1 soda carbonate 53.3g1
58.9 g of zinc oxide was mixed and pre-fired at 350°C for 1 hour, then melted in an electric furnace at 1100-1200°C for 1 hour, and then poured onto an iron plate to be rapidly cooled.

This was finely pulverized to 100 mesh. The softening temperature of the obtained glass was 440°C. A desired molding material was obtained by mixing 60 g of this glass binder powder and 40 g of mica powder in a vibrating mill. Using 16 g of this molding material, 480'Cl9OOk9/CFl! A disk (50n1/mΦ) was molded under conditions of , 5 minutes. Thickness 2.75m/m
, specific gravity 2.92, boiling water absorption 0.5%, no change in appearance after boiling, no change at all even after heat treatment at 300°C for 4 hours. The insulation resistance was 1013Ω under normal conditions and 1010Ω after boiling. Example 5 Zinc heavy phosphate [Zn(H2PO4)2.2H20]25
2.6g 1 soda carbonate 88.9g 1 zinc oxide 172.6
A glass binder powder having a softening temperature of 390° C. was obtained in the same manner as in Example 1 by mixing G1.

A molding material was obtained by mixing 50 g of alumina with 50 g of this glass binder.

Claims (1)

[Claims] 1 A low melting point glass composition powder having the following composition: Na_2O: 7.5 to 14% by weight, ZnO: 20 to 50% by weight, P_2O_5: 35 to 65% by weight is used as a binder, and on the other hand, An inorganic molding material characterized in that an inorganic filler is added and mixed in an amount of 0.1 to 2.5 times on a weight basis. 2 A low melting point glass composition powder having a composition of Na_2O: 7.5 to 14% by weight, ZnO: 20 to 50% by weight, P_2O_5: 35 to 65% by weight, B_2O_3: 35% by weight or less is used as a binder, and An inorganic molding material characterized in that an inorganic filler is added and mixed in an amount of 0.1 to 2.5 times by weight.