Abstract: Provided are: a mold material having improved fluidity and being capable of improving a filling rate of a forming mold during formation of a casting mold; and a mold material that gives cast products a favorable casting surface, effectively improves sand adhesion on cast products, and advantageously provides a casting mold having excellent strength. The mold material is formed as a coated sand in a wet state with spherical particles of silicone resin having binder repellency existing on its surface, by at least mixing a water-soluble inorganic binder in the liquid state having a viscosity of not more than 1000 cP, and the spherical particles of silicone resin, with a refractory aggregate.

Abstract: Provided are: a coated sand having improved fluidity and being capable of improving a filling rate of a casting mold to be obtained; and a coated sand for advantageously manufacturing a casting mold having excellent strength, which coated sand provides a casting mold with good mold-releasability and collapsibility, gives cast products a favorable casting surface, and effectively improves sand adhesion on cast products. The coated sand is formed as a dry granular material having fluidity at room temperature, in which the surface of a refractory aggregate is coated with a solid layer of a water-soluble inorganic binder, and spherical particles of silicone resin having binder-repellency exist on the surface of the binder layer, or form a layer on the surface of the binder layer, a part of the spherical particles being not covered with the water-soluble inorganic binder and being exposed.

Abstract: Provided are: a coated sand having improved fluidity and being capable of improving a filling rate of a casting mold to be obtained; and a coated sand for advantageously manufacturing a casting mold having excellent strength, which coated sand provides a casting mold with good mold-releasability and collapsibility, gives cast products a favorable casting surface, and effectively improves sand adhesion on cast products. The coated sand is formed as a dry granular material having fluidity at room temperature, in which the surface of a refractory aggregate is coated with a solid layer of a water-soluble inorganic binder, and spherical particles of silicone resin having binder-repellency exist on the surface of the binder layer, or form a layer on the surface of the binder layer, a part of the spherical particles being not covered with the water-soluble inorganic binder and being exposed.

Abstract: Provided are: a mold material having improved fluidity and being capable of improving a filling rate of a forming mold during formation of a casting mold; and a mold material that gives cast products a favorable casting surface, effectively improves sand adhesion on cast products, and advantageously provides a casting mold having excellent strength. The mold material is formed as a coated sand in a wet state with spherical particles of silicone resin having binder repellency existing on its surface, by at least mixing a water-soluble inorganic binder in the liquid state having a viscosity of not more than 1000 cP, and the spherical particles of silicone resin, with a refractory aggregate.

Abstract: Provided are a phenolic resin composition for shell molding that has low thermal expansion properties and high flexibility, a resin coated sand for shell molding obtained by using the same, and a shell mold formed of the same. The phenolic resin composition for shell molding that is capable of exhibiting advantageous mold characteristic is obtained by a combination of a phenolic resin that is obtained by a reaction of a phenol, a naphthol, and an aldehyde, and a fatty acid amide.

Abstract: Provided are a phenolic resin composition for shell molding that has low thermal expansion properties and high flexibility, a resin coated sand for shell molding obtained by using the same, and a shell mold formed of the same. The phenolic resin composition for shell molding that is capable of exhibiting advantageous mold characteristic is obtained by a combination of a phenolic resin that is obtained by a reaction of a phenol, a naphthol, and an aldehyde, and a fatty acid amide.

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.