Patent ID: 6599577
Filing Date: 2003-07-29
Classification: C08G

Abstract:
A method for preparing a degradable water-resistant and oil-resistant protective membrane upon a tableware substrate, comprising:obtaining a copolymer of epoxide and carbon dioxide by catalytic reaction having a molecular weight between about 80,000 and about 200,000 wherein the copolymer structure is greater than 98% alternating and wherein the carbon dioxide content of the copolymer is greater than 40%; dissolving the copolymer in a solvent having little or no toxicity; holding the dissolved copolymer for a period of about 2 to about 12 hours; filtering the dissolved copolymer until the residual metal ion content of the dissolved copolymer remaining from catalysis is reduced below 5.0 ppm; adjusting the content of the dissolved copolymer to about 3 to about 6 wt % copolymer in solution; coating the tableware substrate with the dissolved copolymer; and drying the dissolved copolymer to a thickness of about 10 micrometers to about 30 micrometers.