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US 5,171,820 AGranted
Hydroxy-functional polyesters as thermoplastic barrier resins
AssigneeThe Dow Chemical Company
InventorsMichael N. Mang, Jerry E. White
Life of this patent
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Abstract
Polyesters having improved barrier to oxygen are normally solid, thermoplastic methylol polyesters having backbone repeating units containing pendent hydroxyl and methylol moieties and divalent organic moieties such as m-phenylene, p-phenylene, and isopropylidene diphenylene. Such polyesters are prepared by reacting diglycidyl esters of aromatic diacids such as diglycidyl terephthalate or diglycidyl ethers of dihydric phenols with diacids such as isophthalic acid.
Claims16
A normally solid, thermoplastic methylol polyester having repeating units represented by the formula:
- ##STR25## wherein each of R.sup.1 and R.sup.2 is individually a divalent organic moiety which is predominantly hydrocarbon, each R.sup.3 is individually hydrogen or lower alkyl, y is a fraction from 0 to 0.5 and x is a fraction from about 0.05 to about 0.4.
Dependencies are inferred from the claim text.