MODIFIED PET POLYMERS AND COPOLYMERS SUITABLE FOR EXTRUSION BLOW MOLDING

摘要

71173-21 There is disclosed an improved modified polymer suitable for use in making hollow containers by conventional extrusion blow molding. It is a specific type of end-capped and branched polyethylene terephthalate polymer or copolymer. In the improvement, the end-cap comprises the reacted component of a difunctional acid or alkali metal salt of a difunctional acid having the formula: wherein: X has a valency of 6 and is selected from sulfur, selenium, and tellurium; M is an alkali metal or hydrogen; and Y is hydrogen or an aliphatic group containing from 1 to 18 carbon atoms. The preferred difunctional acid is msulfobenzoic acid. The product typically contains few large gels having diameters greater than 0.1 mm.