BENZYL ETHER PHENOL RESIN BASED BINDER CONTAINING FREE PHENOL AND FREE HYDROXYBENZYL ALCOHOLS Russian patent published in 2021 - IPC B22C1/16 

FIELD: casting of metals.

SUBSTANCE: invention relates to manufacture of molds and cores used in casting of metals. The binder is comprised of polyol component which constitutes a benzyl ether phenol resin; isocyanate component composed of one or more isocyanate compounds with at least two isocyanate groups per molecule; wherein the binder contains less than 3% wt. of free phenol and the salicyl alcohol content in the binder is between 1 and 16% wt. and the hydroxybenzyl alcohol content in the molding material mixture is between 1 and 26% wt., wherein each case is calculated for weight of the benzyl ether phenol resin, and the binder is characterized by one or both of these attributes: a) the binder contains free phenol and free hydroxybenzyl alcohol with a weight ratio of 1:more than 1.2; b) the binder contains free phenol and free salicyl alcohol with a weight ratio of 1:more than 1.1. The invention also relates to mixtures of molding material containing a binder and to cores, molds and ingot casts manufactured using mixtures of molding material and to use thereof in casting of metals.

EFFECT: technical result is a binder increasing durability of heated sand molds and cores.

25 cl, 4 tbl