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US 4,234,738 AGranted
Hydroxy terminated polybutadiene based polyurethane bound propellant grains
AssigneeThiokol Corporation
InventorsWilliam H. Graham, Inella G. Shepard
Life of this patent
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Abstract
Salicylate esters have been found to be suitable blocking agents for polyisocyanates, enabling preparation of hydroxy terminated polybutadiene based polyurethane bound propellant grains having extended pot life. Unblocking occurs readily at normal propellant cure temperatures, allowing normal cure rates.
Claims12
A compound of the formula:
- ##STR3## wherein X is an n+m valent organic radical;
- R is hydrogen or lower alkyl of from 1 to about 10 carbon atoms;
- R' is lower alkyl of from 1 to about 10 carbon atoms;
- a carbocyclic aryl of from 6 to about 10 carbon atoms;
- n is on the average at least 1;
- m is 0 or 1;
- and m+n must be at least 2.
4 more elements
Dependencies are inferred from the claim text.