Patent ID: 8840976

Claim:
A containment device comprising: an opening configured to receive a volatile organic compound or a compressed gas, the containment device including a volume surrounded by a wall; and wherein the wall is made from a polymer composition comprising: a) a polyoxymethylene polymer in which at least 50% of the terminal groups are hydroxyl groups, the polyoxymethylene polymer also containing low molecular weight constituents having molecular weights below 10,000 dalton in an amount less than about 10% by weight, based on the total mass of polyoxymethylene polymer; b) an impact modifier comprising a thermoplastic elastomer, the impact modifier being present in an amount of at least about 5% by weight, the impact modifier being chemically attached to the polyoxymethylene polymer; (c) a coupling agent that chemically attaches the impact modifier to the polyoxymethylene polymer; and wherein the polymer composition has a permeation of less than 5 g mm/m2 per day at 40° C. according to SAE Test J2665.