A substantially uniform blend of (A) at least one copolyetherester having a melting point of at least 120.degree.C. which is prepared from a dicarboxylic acid, a low molecular weight diol and poly(tetramethylene oxide) glycol and (B) at least one polyetherester, which may be a copolymer. If a polyetherester is to be utilized it is prepared from poly(tetramethylene oxide) glycol and a dicarboxylic acid. If a polyetherester copolymer is to be utilized it is prepared from a dicarboxylic acid, a low molecular weight diol and poly(tetramethylene oxide) glycol. In any event, component (B) must be noncrystalline above 0.degree.C. and have an inherent viscosity above about 0.3. Component (B) will comprise about 5-50 weight percent of the blend and component (A) about 95-50 weight percent. Optionally up to about 5 percent of an antioxidant may also be present.
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.
The present invention relates to thermoplastic moulding compositions of (A) 99.5 to 80% by weight, of at least one amorphous linear polyamide and (B) 0.5 to 20% by weight of at least one segmented thermoplastic elastomeric copolyester. These novel moulding compositions combine good toughness and hardness with good elongation and stiffness properties as well as good flowing properties of the molten material.
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.
A process is provided for preparing an elastic film of a specific elastomeric composition which is formed by melt blending two particular elastomers, each of which is composed of hard and soft segments made from poly(tetramethylene ether)glycol, 1,4-butane diol and a phenylene dicarboxylic acid or a derivative thereof. One of the elastomers has an inorganic anti-blocking agent compounded in it. The process includes the steps of melt blending, melt extrusion, quenching and providing a draw-down of 12 to 40 to form a film which is particularly suited for use as elastic leg-strips in diapers.
An improved shaped article can be prepared from a blockcopolyetherester by (a) mixing the same with poly(butylene terephthalate) at a temperature of about 200.degree. to about 230.degree. C. whereby fine fragments of poly(butylene terephthalate) which maintains its own crystalline phase are dispersed in the matrix of the blockcopolyetherester, and (b) molding the mixture at a temperature below the melting point of the poly (butylene terephthalate). The addition of an ester wax and/or a calcium soap improves the extrusion-moldability of the mixture.
