BINDING COMPOSITION FOR MIXTURES Russian patent published in 1994 - IPC

FIELD: foundry practice, particularly compositions of mixtures hardened by blowing with sulfur dioxide while making cores and molds. SUBSTANCE: product of reaction of ethyl ethers of orthosilicic acid with furfuryl alcohol in the binding composition is constituted by tetrafurfuryloxisilanes or furfuryloxysiloxanes or ethoxyfurfuryloxisiloxanes. The latter are produced by interaction of commercial oligoethoxysiloxane in the form of ethylsilicate containing 30-60 wt. -% silicon in terms of silicon dioxide with furfuryl alcohol. Ethoxyfurfuryloxysiloxanes contain ethoxy- and furfuryloxy-groups at mole relation, respectively, of 1: (1-19). Ethoxyfurfuryloxysilanes contain ethoxy- and furfuryloxy-groups at mole relation, respectively, of 1: (1/3-3). Binding composition has the following components, wt. -% : acid-hardened epoxy resin, 23-72; product of interaction of ethyl ethers of orthosilicic acid with furfuryl alcohol (in terms of basic substance), 8-52; organic peroxide or/and hydroperoxide, the balance. EFFECT: higher strength and heat resistance of hardened cores and molds and improved sanitary labor conditions. 8 cl, 2 tbl