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US 5,859,091 AGranted
No-bake foundry mixes and their use
AssigneeAshland Inc.
InventorsChia-hung Chen, Thomas E. Dando
Life of this patent
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Abstract
This invention relates to polyurethane-forming foundry binder systems and foundry mixes which comprise a foundry aggregate, said foundry binder system, and a liquid amine curing catalyst. The binder system comprises a polyol component containing a polyether polyol and a monomeric glycol, and an organic polyisocyanate component. The foundry mixes are used to prepare foundry shapes made from foundry mixes by a no-bake process.
Claims8
A no-bake process for the fabrication of foundry shapes comprising:
- A. introducing a foundry mix into a pattern where said foundry mix comprises:
- (1) a foundry aggregate;
- (2) a binder comprising:
- (a) a polyol component comprising
- 1. a polyether polyol;
- and
- 2. a monomeric polyol,
- wherein the weight ratio of polyether polyol to monomeric polyol in the polyol component is from 70:30 to 30:70 and such that the polyol component contains less than 15 weight percent of phenolic resin,
- (b) an organic polyisocyanate component wherein components (1) and (2) are compatible with each other;
- and
- (3) a catalytically effective amount of a liquid tertiary amine catalyst;
- B. allowing the foundry mix to harden in the pattern until it becomes self-supporting;
- and
- C. thereafter removing the shaped foundry mix of step B from the pattern and allowing it to further cure, thereby obtaining a hard, solid, cured foundry shape.
11 more elements
Dependencies are inferred from the claim text.