SU730450A1 - Paint for casting moulds and cores - Google Patents

Description

(54) PAINT FOR CASTING FORMS AND RODS

The invention relates to foundry and can be used in the manufacture of molds and cores in the production of iron casting. The known paint for casting molds and rods containing a polyvinyl acetate emulsion, talc, salt and water 1. The disadvantages of the known anti-stick coating are the high consumption of polyvinyl acetate emulsion, the high gas-forming ability and, as a result, the increased scrap of castings in gas shells. proposed is paint 2 for casting molds and cores containing, by weight. Fireproof. Clay Graphite silver Carboxymethylcellulose Sulphite-alcohol bard with a density of 1.27 g / cm58-12 However, this paint has a high gaseousness, which leads to marriage of castings. The purpose of the invention is to reduce the gas-producing ability (and the rejects of castings on gas shells. The goal is achieved by the fact that paint for casting molds and cores contains organic latex and, in addition, a surfactant, polyethylene glycol ether of alkylphenols with ethylene oxide number O on-lO) in the following ratio of ingredients, wt.%: Talc Carboxymethyl, 3-0.5, cellulose 2.5-3.5 Latex Surface active material, 15-0.17 substance Water Remaining In this case, paint is obtained by density, on the areometer 1.32-1.36 g / cm.

Talc brand TRPN according to GOST 19729-74 is used as a refractory filler.

SCS-65GP latex according to GOST 10564-75 — a product of the joint polymerization of butadiene with styrene in an aqueous emulsion using nickel as an emulsifier — is used as a binder.

The surfactant OP-U-according to GOST 84-33-57-polyethylene glycol ether alkylphenols with an ethylene oxide number of 10 is used as a wetting agent. Density, g / cm1,32 Durability by hardness gauge, mm0,5 Covering ability is good Gas-creating ability, cm / g25 Surface cleanness Drip-proofs no Number of cracks calcined in the sampleNo Sedimentadionic stability72

From tal. 2 that the composition No. 2 has the best properties.

When the latex content is less than 2.5%, the required strength of 85/500 grade carboxymethyl cellulose (CMC) according to GOST 5.588-70-sodium cellulose-glycolic acid is obtained. .

In tab. 1 shows the composition of the paint, and in table. 2 - their physical, mechanical and technological properties.

,Table

Table 2

Claims (2)

ti coverage. When the latex content exceeds 3.5%, the gas-forming ability of the coating increases, and the viscosity also increases, which makes its application difficult. 1.34 1.3 0.50.5 good good 2228 Driping Driping no netNetNetNet 7068 When the CMC content is less than 0.3%, the tendency of paint to sag increases, i.e., the sedimentation stability is insufficient. An increase in the CMC content of over 0.5% leads to an increase in the gas production of the cover. An increase in the OP-10 surfactant content above 0.17% leads to the formation of a large amount of foam, making it difficult to apply paint to the rods and molds. When the OP-10 surfactant content is less than 0.15, there are smudges on the painted surfaces. When the content of talc more than 35% of the coating has a greater density. The paint preparation is carried out as follows. The CMC is soaked in a small amount of hot water and stirred until a homogeneous solution is obtained. An even amount of water is poured into the mixer, and then the coating components are introduced in the following order: OP-10 surfactant talc, latex, CMC solution. After entering each component, the contents of the mixer are mixed until a homogeneous mass is obtained. Application of the proposed paint will improve the quality of castings, eliminate burns and cuts on their surface. DETAILED DESCRIPTION OF THE INVENTION Paint for casting molds and cores, including talc, carboxymethyl cellulose, organic binder, and water, is different in that, in order to reduce the gas-making ability and scrap of castings on gas shells, it contains the active substance is polyethylene glycol ether alkylphenols with the number of ethylene oxide 10 (OP-10) in the following ratio of ingredients, wt.%; Carboxymethyl, 3-0.5 cellulose and 2.5-3.5 Latex Pouratnoactive 0.15-0.17 substance Remaining Sources of information taken into account during the examination 1, USSR Copyright Certificate 531625, cl. B 22 C 3/00, 1975. 2. Authors certificate of the USSR 499025, cl. B 22 C 3/00, 1974.