Patent ID: 6727342
Filing Date: 2004-04-27
Classification: C08L,Y10T

Abstract:
A method of making a biodegradable article having a permeability to water vapor of less than 350 gÃ—30 &mgr;m/m2 per day at 38Â° C. and 90% RH comprising:manufacturing articles from aliphatic polyester resin, wherein said aliphatic polyester resin further comprises a) recurring units X=[Oâ€”(CH2)nâ€”OCOâ€”(CH2)mâ€”CO] and/or Y=[Oâ€”(CH2)kâ€”CO], where the half-sum of n+m is equal to or greater than 6 and k is a number equal to or greater than 6, or by copolymers comprising units and/or sequences having the formula xi[Oâ€”(CH2)niâ€”OCOâ€”(CH2)miâ€”CO]; yj[Oâ€”(CH2)kjâ€”CO] where: i, j=1-5; ni=2-22; mi=0-20; kj=1-21; &Sum;i=15&it;xi+&Sum;j=15&it;yj=1and xi and yj vary between 0 and 1 and are molar fractions of the various units such that &Sum;i=15&it;xi&CenterDot;(ni+mi2)+&Sum;j=15&it;yj&CenterDot;kj&GreaterEqual;6,orb) recurring units Z=[Oâ€”(CH2)a-OCOâ€”(CH2)b-CO] where a=2-3, b=7-11, and has an intrinsic viscosity (in chloroform at 25Â° C.) greater than 0.7 and up to 2.5 dl/g, a melting point from 60Â° to 110Â° C., and a biodegradability such that, under composting conditions, a 30 &mgr;m film of said resin shows a decomposition of less than 10% in 14 days and more than 90% in six months.