SU1463376A1 - Composition for obtaining antistick coating in moulds and cores - Google Patents

Abstract

The invention relates to foundry and is intended to produce anti-stick coatings on molds and cores in the production of predominantly cast iron castings. The purpose of the invention is to reduce the roughness of castings by reducing the gas-gas content of the coating and increasing its heat resistance. The composition contains the following ingredients. Wt.%: Polystyrene 1-15, kerogen 2-30, distillation residues of vinylidenechloride 55-97. The coating on the molds and cores is obtained by applying them - the composition and its subsequent drying in air for 20-25 minutes. The effectiveness of the coating obtained is due to the combination of kerogen and polystyrene in its composition. The use of distillation residues of vinylidene chloride as a solvent makes it possible to reduce the cost of coating. The use of the composition according to the invention makes it possible to increase the depth of the surface layer of the forms and cores and thereby increase their strength, reduce the roughness of the surface of the castings, increase the heat resistance of the coating and reduce its gas-blowing ability. 3 tab. t (L

Description

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This invention relates to a foundry, in particular, compositions for producing nonstick coatings on foundry molds and cores of predominantly cast iron casts.

The purpose of the invention is to reduce the roughness of castings by reducing the gas-gas content of the coating and increasing its heat resistance.

The composition contains polystyrene and kerogen as a non-stick ingride. Kerogen is a concentrate of organic matter from shale mixed with mildness.

For example, a plasticizer PN-6 (petroleum oil) or other oils can be used as a softener.

Physico-chemical indicators of kerogen are given in table.1.

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As a solvent, the composition contains distillation residues. Rectification of vinylidene chloride consisting of the following ingredients, in May.%: Vinylidene chloride 24.0-25.0 Transdichloroethylene, 0-7.0

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Cisdichloroethipene 1-2 Dichloroethane Trichloroethyles Trushloretan 1,1-Dichloroethane

4.0-5.0

0.3-0.5

30.0-34.0

6.0-7.0 22.0-25.0

The process of making the nonstick coating is as follows.

Polystyrene is added to the paint mixer of the Blyvagot type of the solvent and, with mixing, in small portions until complete dissolution51.

After that, the calculated amount of kerogen is added and additional mixing is carried out for 7-10 minutes.

. Thus obtained composition is applied a. surface-ing forms or rods. by spraying or dipping in individual, serial and mass production of castings. Painted molds or rods are kept for 20-25 minutes in air until complete curing of composition a and obtaining a coating on them, after which rods or molds are supplied for assembly and casting. The composition for making the nonstick coating is shown in Table 2, and the resulting coating properties and the quality of the castings are given in Table 3.

:. use efficiency of coating-:; The composition of the proposed composition is determined by the combination of carbon-containing substances, such as kerogen and polystyrene, which, when decomposed by the metal process, emit shiny carbon on the surface and form a layer on the surface that is not wetted by the liquid metal, which prevents The penetration of metal oxides deep into the mold and the reaction of the metal with the mold material. With goatom, carogen in the process of destruction releases 20-26% of bright carbon, which increases the nonstick properties of the coating.

In addition, kerogen has a fine grinding, almost insoluble in organic solvents and when applied to the surface of the molds and rods easily penetrates into the pores, fills them, thereby reducing the penetration depth of the liquid metal into the depths of the mold. This contributes to the production of iron castings with improved surface quality. Use as a solvent bottoms of rivers

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typification of vinylidene chloride, which is a production waste, makes it possible to reduce the cost of the composition of the proposed

f, cover and partially solve the problem of creating wasteless technological processes. Distillation residues of vinylidene chloride are dissolved. polystyrene without precipitation and

10 less volatile than aromatic solvents such as acetone, which favorably affects the working conditions. At the same time, the coating applied to the forms and Ster15 from the proposed composition does not require a special drying operation.

The surface of the rods, painted compositions, has no cracks and stains, has sufficient strength. The obtained castings with these rods have a clean surface without piercing.

Using coatings of the proposed composition allows increasing the depth of impregnation of the surface layer of molds and cores and thereby increasing ix strength, reducing the surface roughness of castings, increasing the heat resistance of the coating and reducing its gas-forming ability, reducing the cost of coating and providing a clean smooth surface of thick-walled castings.

Claims (1)

Invention Formula The composition for producing a non-stick coating on casting molds and cores mainly in the manufacture of cast iron castings, including polystyrene and a solvent, characterized in that 5 in order to reduce the roughness of castings By reducing the gas creativity and increasing its heat resistance, it additionally contains kerogen, in quality, solvent - distillation residues of vinylidene chloride in the following ratio of ingredients, wt.%: Polystyrene Keporett Vat, residues of rectification of vinylidero psoride 1-15 2-30. 55-97 Moisture content,%, not more Density, g / cm, not more than Oil content,% Content of conditional organic matter of shale in oil-free kerogen in terms of dry product,% 3.0 1.35 14 + 2 3.0 1.35 18 + 2 20 + 2 70 + 2 Table 2. Distillation residues of vinylidene chloride. 55 76 97 Coating properties and casting quality Depth of impregnation, mm Gas capacity, cm / g Surface roughness of castings, mkm The performance properties for the compositions of table 1 T R 3 3-5 2-5 1245 80