A specific elastomeric composition is formed by melt blending two particular elastomers, each composed of hard and soft segments made from poly(tetra-methylene ether) glycol, 1,4-butane diol and a phenylene dicarboxylic acid or a derivative thereof. The blend exhibits a melting endotherm that extends from no lower than 120.degree. C. to no higher than 215.degree. C. with a melting peak in the range of 150.degree. to 175.degree. C. Films made from the composition are particularly suited for use as elastic leg-strips in diapers.
The invention relates to a copolyether ester composition for products that show particularly good aging behaviour when exposed to dynamic deformation at elevated temperatures and in contact with greases. The copolyether ester composition comprises a mixture of at least 2 copolyether esters A and B, composed of hard segments derived from at least one alkylene diol and at least one aromatic dicarboxylic acid and soft segments derived from at least one polyalkylene oxide glycol and at least one aromatic dicarboxylic acid, in which the concentration of soft segments X in A and the concentration of soft segments Y in B lie between 30 and 65 wt. %, relative to the copolyether ester and the molecular weights of X and Y lie between 500 and 3000 and .vertline.M.sub.x -M.sub.y.vertline..gtoreq.400.
A segmented copolyetherester elastomer has soft segments formed from 60-95% poly(ethylene oxide) glycol and 40-45% of a second poly(alkylene oxide)glycol, preferably poly(tetramethylene oxide) glycol, and hard segments formed from terephthalic acid and ethylene glycol or 1,4-butane diol, the hard segments amounting to 8-20% of the elastomer weight. The elastomer can be molded into soft, elastic objects and can absorb water amounting to at least 100% of its dry weight.
An improved thermoplastic, segmented, linear copolyetherester elastomer having hard segments derived from diols and diacids which provide divalent cyclo-aliphatic radicals having a structure depicted by a formula which is ##STR1## Preferably the diol and diacid radicals are each at least 40% trans isomer and either one or the other radical is at least 70% trans isomer. The elastomers are suited for use as rubber-band substitutes, elastic strips, elastic coatings and the like.
Talc filled thermoplastic polyester compositions which have been modified by the addition of a butadiene-based impact modifier are stabilized against degradation by the addition thereto of a specific phosphorous compound.
