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US 5,874,487 AGranted
Foundary binder systems which contain alcohol modified polyisocyanates
AssigneeAshland Inc.
InventorsRina Singh, Laurence G. Dammann
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Abstract
The invention relates to foundry binder systems which use modified polyisocyanates. The modified polyisocyanates are prepared by reacting a polyisocyanate with an aliphatic alcohol having one active hydrogen atom. These modified polyisocyanates, along with a phenolic resole resin, are added to a foundry aggregate to form a foundry mix which is shaped and cured with a gaseous amine curing catalyst.
Claims12
A process for preparing a foundry shape by the cold-box process which comprises:
- (a) forming a foundry mix comprising;
- A. a major amount of aggregate;
- and
- B. an effective bonding amount of a binder system, curable with a catalytically effective amount of an amine curing catalyst, where said binder system comprises as separate components:
- (1) a phenolic resin component;
- and
- (2) a polyisocyanate component comprising a polyisocyanate modified with an aliphatic alcohol having one active hydrogen atom and from 6 to 50 carbon atoms, wherein the amount of said aliphatic alcohol used to modify the polyisocyanate is from 0.5 mole percent to 50 mole percent;
- (b) forming a foundry shape by introducing the foundry mix obtained from step (a) into a pattern;
- (c) contacting the shaped foundry mix with a tertiary amine catalyst;
- and
- (d) removing the foundry shape of step (c) from the pattern.
8 more elements
Dependencies are inferred from the claim text.