SU1184601A1 - Parting paint for moulds and cores - Google Patents

Abstract

ANTI-DRIVE PAINT FOR CASTING FORMS AND RODS, including cryptocrystalline graphite, polyvinyl butyral and ethyl alcohol, characterized in that, in order to improve the quality of the paint by increasing its sedimentation stability and opacity, the paint additionally contains a heat-treated solvent, and a solvent with a suitable solvent. ingredients, wt.%: Polyvinyl butyral 1.9-2.5 Ethyl alcohol 50,5-51,2 Thermo-activated diatomite 5-10 Cryptocrystalline The Rest

Description

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O5 The invention relates to foundry, in particular, to non-stick paint formulations for foundry molds and STARS containing an organic binder and solvents in the manufacture of iron castings. The purpose of the invention is to improve the quality of paint by increasing its sedimentation stability and covering power. Non-stick paint contains polyvinyl butyral, graphite, ethyl alcohol and thermo-activated diatomite. An increase in the sedimentation stability and covering ability of the entire disperse system is promoted by diatomite with a highly developed inner surface. Such diatomite is obtained after drying natural diatomite at 400-600 ° C with grinding to sizes of 10 μm and less, calcining in a flowing boiling bed at 1 100-400 ° C. When calcining the organic and external residues from the outer and inner surfaces of the particles, the magnesium, iron and alumina H1 silicates partially decompose, resulting in the openwork particles of distomite with many cavities (holes). The solution of the binder in the solvent during the preparation of paint is fonicait in these pores and with their centers activated during calcination, forms a complex system. Such a system is stable due to the presence of bridges from diatomite, since its developed surface has an excess of surface energy. The use of crushed and dried diatomite for this purpose, which did not undergo a special high-temperature treatment, does not give the desired result, since a significant 1a of the inner surface of the particles (pores) is covered by mineral remains of fossil organisms, from which deposits are formed. . Diatomite has the following chemical composition in terms of dry matter wt.%: SiOa80--93 FeOj0.5-2.0 AlgQs2.0-4.0 CaO ca. 2.0 MgO ca. 2.0 Organic substances Remaining Calcined) 1st diastomite with a particle size of up to 3 μm is 15% of the total content, size of 3-10 microns and 10-50 microns of 5%. The surface area is (average) about 120. Because the chemical composition of diatomite does not affect the indicated limits, sedimentation resistance of the paint is not affected. Graphite was used as a fireproof filler in the compositions of nonstick paints, and technical alcohol was used as a solvent. Other solvents that can dissolve polyvinyl butyral can be used, such as isopropyl alcohol, acetone, shoe granitol solvent, K 646, No. 647, etc., since the viscosity of a solution of polyvinyl butyral varnish is almost the same. When the content of thermoactivated diatomite is below the lower limit, the sedimentation stability of the paint is unsatisfactory, and when its content is above the upper limit, as the paint is mixed, air bubbles are formed throughout its volume, which are the source of the formation of pores in the hardened paint layer. The nonstick paint is prepared as follows. In a paddle-type closed mixer, the graphite is hidden, cryptocrystalline and diatomite according to the composition of the ink and mixed for 3-5 minutes. Then, the calculated amount of polyvinyl butyral, previously dissolved in ethanol, is introduced, and all components are mixed until a homogeneous suspension is obtained (7-10 minutes). The sedimentation stability of the paint is estimated by the coefficient of delamination when the paint is settled for 1.3 and 24 hours: Cr cm1 ishh where the AT is the difference in ink density between the lower and upper sections of the sedimentometer, Z nsx is the original ink density h is the distance between the sections of the sediometer. The coating ability of paints is evaluated visually by the uniform distribution of paint over the painted surface (without incrustations). In tab. 1 shows the compositions of paint 1-3 (proposed) and 4 (known). The test results of paints 1-4 are given in table. 2. From the data table. 2, it follows that the paint according to the invention has an increased cedi. Resistance and covering power. These compounds form on the surface of the molds and rods an even (without smudges) layer of paint. Paints can reduce the content of expensive and scarce polyvinyl butyral by about 20%. Duration of drying paint 15-20 minutes. The paint can be used for casting molds and cores made of liquid glass or sand resin materials.

mixtures (HTS, ZhSS) in the production of iron, steel and color castings. Expectations Ingredients Graphite GLS Graphite GL Polyvinylbutyral Diatomite Ethyl Alcohol Paint Properties Bundle Ratio (K - K 10), h 24 Good. On the Covering ability of uniform Viscosity (according to VZ-4), with Density, g / cm saving from the use of paint 1.52 r. per 1 ton of suitable castings. Z13 IZLZIlIZIZLZ 42403735 2,52,21,92,5 50,550,851,152,5 ZZ: Z; IZZ :: XZ :: EZ: Z Table 1 Table of contents, wt.%, In paints of compositions --- 10 5710 Table 2 Compositions 1,763.1 2.96.9 3.248.9 Satisfactory coverage -0.45 mm is solid. Coating layer thickness 0.10, 15 mm 4726 1,1451,150

Claims (1)

Nonstick paint for foundry molds and rods, including cryptocrystalline graphite, polyvinyl butyral and ethyl alcohol, characterized in that, in order to improve the quality of the paint by increasing its sedimentation stability and hiding power, the paint additionally contains heat-activated diatomite in the following ratio of ingredients, wt.%. : Polyvinyl butyral Ethanol Thermally activated di 1.9-2.5 50.5-51.2 5-10 atomite Cryptocrystalline graphite chesky Rest 1091ζ8ΙΙ HS