SU407624A1 - CONNECTING FOR ANTI-GRINNING PAINTS - Google Patents

Description

one

This invention relates to a foundry, namely, a binder composition for non-stick paints.

Known binder for non-stick paints, containing in its composition of liquid glass and fluorite filler. However, such binders being used in the compositions of non-stick paints do not provide a clean surface of the castings.

The purpose of the invention is to reduce the wettability of paints with metal melt and increase their mechanical strength.

This is achieved by incorporating lime into the composition of the binder, grated white, soda ash, calcium phosphate, aluminum phosphate, 50% solution of aluminum phosphate in phosphoric acid, and orthophosphoric acid in the following ratio of components, weight. %:

Liquid glass 6.5-17.8 Lime, hydrated white 2.4-3.0 Fluor spar 0.4-1.7 Soda calc0.2-0.5 Calcium phosphate 3.2-4.0 Aluminum phosphate 3.2- 4.0 Phosphoric acid12,8-13,7 50% aluminum phosphate solution in phosphoric acid is a restless one.

Phosphoric acid of 85% concentration is used.

Introduced into the binder liquid

the glass must have a specific weight of 1.4 -

1.43 g / cm and a modulus of 2.6-2.8; lime, gashin

Bel, should be 6-9% moisture. Soda

calcined injected in powder.

Calcium phosphate is obtained by extracting marble powder (CaCO3) with 85% orthophosphoric acid, taken in a ratio of 1:40, but by weight. Aluminum phosphate is obtained by reacting aluminum powder with 85% orthophosphoric acid, taken in a ratio of 1:50 by weight. A 50% solution of aluminum phosphate in orthophosphoric acid is obtained by reacting an oxide hydroxide (A1 {OH) 3) with 85% orthophosphoric acid, taken in a 1: 2 ratio by weight.

Prepare the binder in the spray pot in the following sequence.

Slaked lime, soda ash and fluorspar are mixed until a homogeneous mass is obtained, then with mixing the liquid glass is introduced into a thin stream and, without stopping the mixing, calcium phosphate, aluminum phosphate and phosphoric acid are introduced.

Finally, a 50% solution of aluminum phosphate in orthophosphoric acid is introduced with continuous stirring.

g

An example of a non-stick paint with the proposed binder is, (wt.%): Alumina base

Fine potassium potassium shiata (0.2 sieve) with a K2OA12Oz-65102 content of at least 90% 2.0-8.0

Binder 20-50

The coating is prepared by mixing in a dry paint component for about 10-15 minutes, then, with a continuous supply of thin binder, the binder is left still for 15-25 minutes until a homogeneous mass is obtained.

The consistency of the coating depends on how it is applied. When coating with a spraying agent, about 50-60% is introduced, and dipping - 30-40%.

Applying a nonstick coating with an atomizer when heating the surfaces to be coated is up to 350-400 ° C, and when dipping in a cold state with subsequent substance up to 350-400 ° C and holding for 4-5 hours.

A nonstick coating with the proposed binder can be used.

also to protect metal pipes, molds, graphite and metal crucibles from exposure to molten metal.

Subject invention

Binder for non-stick paints, including liquid glass and fluorite material, characterized in that, in order to reduce the wettability of the coating with the molten metal and increase its mechanical strength, lime, grated white, soda ash, calcium phosphate, aluminum phosphate, 50% were added to the composition. a solution of aluminum phosphate in orthophosphoric acid and orthophosphoric acid in the following ratio of components, weight. %:

Liquid glass6,5-17,8

Lime, grated belo 2.4-3.0 Hydrofluoric Shpat0.4-1.7

Soda Ash 0.2-0.5

Calcium phosphate 3.2-4.0

Aluminum phosphate 3.2-4.0

Phosphoric acid 12,8-13,7 50% solution of aluminum phosphate in phosphoric acid is a rest.