RAW BLEND Russian patent published in 1997 - IPC

FIELD: manufacture of building materials. SUBSTANCE: invention relates to manufacturing gypsum blends with controlled hardening time for sheet materials and structures and also for decorative and finishing little-size articles on their basis. Blend contains (in %): gypsum, 40.5-66.45; wood filler, 20-30; alkaline waste from production of caprolactam based on mono- and dicarboxylic acids, 0.15-1.35; polydentate chelating ligand, 0.05- 0.5; water, the balance. Using such a blend leads to a considerable increase in hardening time and strength of end items. Beginning and end of hardening of raw blend lye in the ranges 58 min-1 h 15 min and 1 h 20 min to 2 h 38 min, respectively. Strength of final items ranges from 30 to 39 kg/sq.cm. EFFECT: increased strength of material. 1 tbl