SU1204607A1 - Refractory electrc insulating material - Google Patents

Description

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The invention relates to silicate materials and can be used as a high-temperature refractory electrical insulating material and heat-resistant binder in an electrical engineering, radio engineering industry, as well as in ferrous and non-ferrous metallurgy.

The purpose of the invention is to increase the strength, fire resistance and electrical insulation properties of the material after heat treatment in the temperature range of 500-300 ° C.

To obtain a refractory electrically insulating material, talc is ground to a specific surface of 0.3-0.4 m / g and the talc powder is closed with a solution of orthophosphoric acid with a density of 1.45, 60 g / cm. The resulting mixture is thoroughly mixed and from it is molded product plastic or semi-dry method.

The hardening of the products occurs at 200-10 C for 1 h.

Example 1. For preparing refractory electrically insulating material, 90% talc (450 g in the form of a powder with a specific surface of 0.35 m / g and 10% (50 g) of a solution of phosphoric acid H PO, density of 1.55 g / cm is taken. Components mix thoroughly and press the samples from the resulting mixture under pressure, singing 100 MPg with a batch at final pressure of 15-30 s. The pressed samples are dried for 1 hour. Dried samples are calcined in the following mode: temperature rise rate over 200 C is C / min, holding at 1300 ° C for 1 hour.

Example 2. For the preparation of refractory electrically insulating material, 85% of talc (425 g as a powder with a specific surface of 0.4 and 15% (75 g) of a solution of orthophosphoric acid with a density of 1.55 g / cm are taken. Components

Mix well and press the samples from the resulting charge mixture, 80 Dla with a final pressure of 1J-39 s. The pressed samples 5 are dried at 200 ° C for 1 hour. The dried samples are burned according to the following mode: the rate of rise of temperature; Temperatures over 200 ° C are 8-10 C / min, holding at a temperature of 10 ° 1300 ° C - 1 hour.

Example 3. To prepare a refractory electrically insulating material, 75% of talc (375 g) is taken in the form of a powder with a specific surface of 5% of 0.4 and 25% (l25r) of a solution of orthophosphoric acid with a density of 1.60 g / cm. The components are thoroughly mixed and the resulting mixture is formed into samples under a pressure of 50 MPa.

20 with an exposure at a final pressure of 15-30 s. The pressed samples are dried at 200 ° C for 1 hour. The dried samples are calcined according to the following mode: temperature rise rate

25 is 8-10 ° C / min 5; delivery at 1300 ° C is 1 h.

As follows from the table, the use of ingredients in the proposed ratios allows to increase

30 strength, refractoriness and dielectric constant of the material after heat treatment in the temperature range 500-1300 C compared with the prototype. The resulting material in its properties is close to the steatite ceramic.

The technical and economic efficiency of the proposed refractory electrically insulating material is the ability to retain electrical insulation, strength properties when exposed to high temperatures in the range of 500-1300 C.

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The expected economic effect is 430 thousand rubles. per year, taking into account the low cost of the components used and the high technical properties of ready-made products.

Claims (1)

. FIRE-RESISTANT ELECTRIC INSULATION MATERIAL, containing 75-90 wt.% Filler of magnesium silicate and 10'25 wt.% Phosphoric acid, characterized in that, in order to increase the strength, fire resistance and electrical insulation properties of the material after heat treatment in the temperature range 500-1300 C, it contains talc as a filler. SU, 1204607