Production of high molecular weight polyoxymethylenes

Claim 1

A PROCESS FOR THE PRODUCTION OF POLYOXYMETHYLENE OF A MOLECULAR WEIGHT OF MORE THAN 10,000, WHICH COMPRISE POLYMERIZING MONOMRIC FORMALDEHYDE CONTAINING ABOUT 1 TO ABOUT 5% BY WEIGHT OF WATER IN A SUBSTANTIALLY ANHYDROUS ACYLATION AGENT FOR SID POLYOXYMETHYLENE IN THE PRESENCE OF A CATALYTIC AMOUNT OF A DIVALENT TIN SALT OF A CARBOXYLIC ACID HAVING UP TO 20 CARBON ATOMS, SAID CATALYTIC AMOUNT BEING UP TO 0.006 MOL OF SAID CATALYST PER MOLE OF MONOMERIC FORMALDEHYDE AND SAID POLYMERIZING BEING EFFECTED AT A TEMPERATURE OF ABOUT -20 TO ABOUT +70*C., AND RECOVERING RESULTING POLYOXYMETHYLENE OF A MOLECULAR WEIGHT OF MORE THAN 10,000 FROM SAID SUBSTANTIALLY ANHYDROUS ACYLATION AGENT.