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US 4,731,126 AGranted
Composition and method for purging polymeric residues
AssigneeThe Dow Chemical Company
InventorsThuan P. Dixit, David V. Dellar
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Abstract
Compositions comprising thermoplastic polymers having added thereto small amounts of a hydroxymethyl-substituted carboxylic acid are usefully employed to remove accumulated polymeric residues from polymer processing equipment.
Claims6
A method for removing accumulated polymeric residue from polymer processing equipment which comprises as the essential cleaning step contacting such equipment with a mixture comprising a thermoplastic polymer and an effective amount to remove accumulated residues of a hydroxymethyl substituted carboxylic acid corresponding to the formula:
- C.sub.m R.sub.2m+2
- wherein R independently each occurrence is hydrogen, --COOH, --CH.sub.2 OH, or an inert substituent, provided that R in at least one occurrence each is --CH.sub.2 OH and --COOH but in not more than three occurrences for every two polymer chain backbone carbons, and m is an integer from one to about 30, said method being carried out in the absence of pentaerythritol.
Dependencies are inferred from the claim text.