PROCESS FOR MANUFACTURING FACING SLAB Russian patent published in 1994 - IPC

FIELD: manufacture of constructional materials. SUBSTANCE: polyester composition including polyester resin grade ПН- 1 and benzoyl peroxide as the curing agent is poured in a built-up mold made in the form of a frame with a flat bottom. Thereafter, an aggregate prepared from a material containing admixture of metal salts is layered onto outer layer of polyester resin composition. Prior to use such aggregate is kept at a temperature of 10-30 C in a sealed container whose air space contains dimethyl aniline vapor at a concentration of 0.05-0.2 mg per 1 m³ to obtain the desired color of aggregate particle surface. After hardening a polyester resin layer up to 90 % of full cure, the resulting prepreg is broken away from the mold bottom. Thereafter, the material is placed onto the mold bottom again, and polymer-concrete mixture of the basic layer is poured on its surface. To obtain more intensive color the aggregate is dipped into a 5-20 % solution of dimethyl aniline in an alcohol and is allowed to stay in a sealed container. After treatment of the aggregate in alcohol solution of dimethyl aniline, it is mixed with an untreated aggregate in weight ratio of 1:1-10 to obtain wider tint spectrum. EFFECT: improved quality. 3 cl, 1 tbl