Stabilization of oxymethylene copolymers with an hydroxy containing reactant

Claim 1

A PROCESS FOR THE STABILIZATION OF A NORMALLY SOLID OXYMETHYLENE POLYMER HAVING A MELTING POINT OF AT LEAST 150*C., SAID POLYMER HAVING AT LEAST ONE CHAIN CONTAINING (1) BETWEEN ABOUT 85 AND ABOUT 99.9 MOL PERCENT OXYMETHYLENE UNITS INTERSPERSED WITH (2) BETWEEN ABOUT 0.1 AND ABOUT 15 MOL PERCENT OF -O-R- UNITS WHREIN R IS A DIVALENT RADICAL CONTAINING AT LEAST TWO CARBON ATOMS DIRECTLY LINKED TO EACH OTHER AND POSITIONED IN THE CHAIN BETWEEN THE TWO VALENCES, WITH ANY SUBSTITUENT IN SAID R RADICAL BEING INERT, AT LEAST PART OF THE TERMINAL UNITS OF THE MOLECULES OF SAID POLYMER BEING COMPRATIVELY THERMALLY UNSTABLE HYDROXY-SUBSTITUTED OXYMETHYLENE UNITS OF HIGHER SUSCEPTIBILITY TO THERMAL DEGRADATION THAN TERMINAL UNITS DERIVED FROM SAID -O-RUNITS, SAID PROCESS COMPRISING REACTING SAID COMPARATIVELY UNSTABLE TERMINAL UNITS OF SAID POLYMER, AT A PH OF AT LEAST 7, WITH BETWEEN ABOUT 0.0001 AND 100 LBS. (PER LB. OF POLYMER) OF A CHEMICAL REACTANT COMPRISING A HYDROXY-CONTAINING MATERIAL SELECTED FROM THE GROUP CONSISTING OF WATER AN ALCOHOL, SAID REACTION BEING FOR A SELECTED TIME BETWEEN ABOUT 15 SECONDS AND ABOUT 10 HOURS, SAID TIME BEING SELECTED SUCH THAT THE REACTION, AFTER EXPOSURE TO SUFFICIENTLY HIGH TEMPERATURE CONDITIONS SELECTED FROM BETWEEN ABOUT 90*C. AND ABOUT 200*C., HAS SELECTIVELY REMOVED SAID COMPARATIVELY THERMALLY UNSTABLE TERMINAL UNITS UNTIL THE INITIAL WEIGHT LOSS RATE OF THE TREATED POLYMER IS BELOW 0.1 WEIGHT PERCENT PER MINUTE MEASURED BY HEATING THE POLYMER AT A TEMPERATURE OF 222*C. IN AN OPEN VESSEL IN A CIRCULATING AIR OVEN.