USO DE RESINAS DE POLIESTERES NA PRODUCAO DE ARTIGOS QUE TENHAM BOAS PROPRIEDADES DE PROTECCAO CONTRA O VAPOR DE AGUA

摘要

Polyester resins formed by recurring units X=[O-(CH2)n-OCO-(CH2)m-CO] and/or Y=[O-(CH2)k-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[O-(CH2)ni-OCO-(CH2)mi-CO]; yj[O-(CH2)kj-CO] where: i,j=1-5; ni=2-22; mi=0-20; kj=1=21; (Formula (1)) and xi and yj vary between 0 and 1 and are molar fractions of the various units such that (Formula (2)), are used for the preparation of products in which a permeability to water vapour of less than 350 gx30 mum/m<2 >per day, measured at 38° C. and 90% RH and good biodegradability are required.