Phenolic resin for shell molding, process for producing the same, resin coated sand for shell molding, and shell mold formed of the same

Abstract

A phenolic resin for shell molding is provided which generates less tar during casting and has low thermal expansion properties and high flexibility. Further, a process for producing the phenolic resin, RCS obtained by using the phenolic resin, and a shell mold obtained by using such RCS are provided. A phenolic resin having advantageous characteristics is obtained by reacting phenols and naphthols with aldehydes in the presence of at least one of divalent metal salt and oxalic acid which acts as catalyst.

Dependencies are inferred from the claim text.