Stabilization of oxymethylene polymers with trioxane hydroxyl containing reactants

Claim 1

THE PROCESS FOR THE STABILIZATION OF A NORMALLY SOLID OXYMETHYLENE COPOLYMER HAVING A MELTING POINT ABOVE ABOUT 150*C. THE MOLECULES OF SAID COPOLYMER CONTAINING FROM 60 TO 99.6 MOL PERCENT OF COMPARATIVELY UNSSTABLE MONOMERIC OXYMETHYLENE UNITS INTERSPERSED WITH COMPARATIVELY STABLE MONOMERIC -OR-UNITS WHEREIN R IS A DIVALENT RADICAL CONTAINING AT LEAST TWO CARBON ATOMS DIRECTLY LINKED TO EACH OTHER AND POSITIONED IN THE POLYMER CHAIN BETWEEN THE TWO VALENCES WITH ANY SUBSTITUENTS ON SAID R RADICAL CONTAINING AT LEAST TWO CARBON ATOMS PORTION OF SAID MOLECULES COMPRISING SAID UNSTABLE MONOMETRIC UNITS, SAID PROCESS COMPRISING (1) REACTING SAID POLYMER, IN SOLID PARTICULATE FORM, WITH A REACTANT COMPRISING (A) BETWEEN ABOUT 5 AND ABOUT 60% TRIOXANE, AND (B) BETWEEN BOUT 40 AND ABOUT 95% FO A HYDROXY-CONTAINING MAATERIAL SELECTED FROM THE GROUP CONSISTING OF WATER, AND ALCOHOL AND MIXTURES THEREOF AND (C) FROM ABOUT 0.001% TO ABOUT 10.0% OF ALKALINE MATERIAL AT A TEMPERATURE WITHIN THE SWELL TEMPERATURE RANGE OF SAID POLYMER IN SAID REACTANT, SAID TEMPERATURE BEING BETWEEN ABOUT 120*C. AND ABOUT 155*C., SAID REACTION PRODUCING A WEIGHT LOSS OF SAID POLYMER AT A FIRST RATE, AND (2) CONTINUING SAID REACTION FOR A TIME SUFFICIENT (A) TO REMOVE AT LEAST 50% OF SAID UNSTABLE MONOMERIC UNITS FROM THE TERMINAL PROTIONS OF SAID MOLECULES AND (B) TO REDUCE THE POLYMER RATE WEIGHT LOSS TO BETWEEN ABOUT 0.1% AND ABOUT 5% OF SAID FIRST WEIGHT LOSS RATE.