Binder for dry sand mold and method of its usage

• US 4,691,759 A
• Filed: 07/22/1986
• Issued: 09/08/1987
• Est. Priority Date: 07/24/1985
• Status: Expired due to Fees

• Current Assignee: Nippon Petrochemicals Co., Ltd. (ENEOS Holdings, Inc.)
• Original Assignee: Nippon Petrochemicals Co., Ltd. (ENEOS Holdings, Inc.)
• Inventors: Kaiya, Atsushi, Yoshida, Takeshi, Hayakawa, Masaru
• Primary Examiner(s): Lin, Koang Y.
• Application Number:
  US06/888,010
• Time in Patent Office: 413 Days
• Field of Search: 164/525, 164/526, 164/527, 164/12, 164/16, 523/139
• US Class Current: 164/526
• CPC Class Codes: B22C 1/2206 obtained by reactions only involving carbon-to-carbon unsaturated bonds

Abstract

The present invention provides a binder for foundry sand which comprises a hydrolyzate of a butadiene/maleic anhydride copolymer, a neutralized or a partially neutralized substance of the hydrolyzate, a modified substance prepared by modifying the hydrolyzate with a basic organic compound, or a mixture thereof.

Claims

1. A method for manufacturing a sand mold for castings which comprises the steps of mixing foundry sand with an aqueous solution of a binder selected from the group consisting of a hydrolyzate of a butadiene/maleic anhydride copolymer, a neutralized or a partially neutralized substance of said hydrolyzate, a modified substance prepared by modifying said hydrolyzate with a basic organic compound, or a mixture thereof so that the amount of the binder in terms of a solid content is within the range of 0.1 to 5 parts by weight based on 100 parts by weight of said foundry sand, and molding, heating, drying and thereby curing the resultant mixture.

2. The method according to claim 1 wherein said binder contains 3 to 97% by weight of a polyvinyl alcohol based on the total weight of said binder.

3. The method according to claim 2 wherein said hydrolyzate is neutralized or partially neutralized with a basic metallic compound or a basic organic compound.

4. The method according to claim 3 wherein said aqueous solution of said neutralized or a partially neutralized substance of said hydrolyzate with a basic metallic compound has a pH value of 6 or less.