초록 ▼

In a mold to be hardened by a CO2 gas, a mold binder material comprising a combination of polymers containing carboxyl groups, at least one of multi-valent metal oxides and multi-valent metal hydroxides, and resins of polyvinyl alcohol group, and at least one of sodium salt of gluconic acid and poly

In a mold to be hardened by a CO2 gas, a mold binder material comprising a combination of polymers containing carboxyl groups, at least one of multi-valent metal oxides and multi-valent metal hydroxides, and resins of polyvinyl alcohol group, and at least one of sodium salt of gluconic acid and polyhydric alcohols or a mold binder material comprising a combination of polymers having carboxyl groups, at least one of multi-valent metal oxides and multi-valent metal hydroxides, and at least one of sodium salt of gluconic acid and polyhydric alcohols is provided. By use of the present binder material, the following various effects can be obtained: (1) easy preparation of mold sand, (2) easy removal of the binder material by water washing even if bodies or clothes are fouled by the binder material, (3) a longer working time of mold sands, (4) a higher mold strength, (5) an improved working atmosphere at shaping of the mold, (6) an improved production efficiency of molds, (7) the desired mold strength being obtained with a smaller amount of CO2 gas used, etc.

대표청구항 ▼

A mold binder material for a mold to be hardened with a CO2 gas, which comprises a combination of an aqueous solution of at least one caustic alkali-neutralized copolymer selected from the group consisting of a800%, on the basis of the caustic-alkali neutralized copolymer, of at least one multi-vale

A mold binder material for a mold to be hardened with a CO2 gas, which comprises a combination of an aqueous solution of at least one caustic alkali-neutralized copolymer selected from the group consisting of a800%, on the basis of the caustic-alkali neutralized copolymer, of at least one multi-valent metal oxide or hydroxide; and 3 to not more than 100% by weight of the sodium salt of gluconic acid or of polyhydric alcohol on the basis of the aqueous solution of caustic-alkali neutralized copolymer.