Abstract: The novel polyester (first polyester [A]) of the invention comprises dicarboxylic acid constituent units derived from at least one dicarboxylic acid selected from terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid and diol constituent units derived from diols comprising ethylene glycol and a polyalkylene glycol having a C2-C10 alkylene chain, wherein the proportion of constituent units derived from the polyalkylene glycol is 0.001 to 10% by weight based on the diol constituent units. The polyester [A] has an excellent crystallization rate, is suitably used, singly or as compositions together with another polyester [B] and/or other polymers, for production of molded products such as films, sheets, laminates, preforms and bottles, which have excellent thermal, gas barrier and transparency properties.

Abstract: A stretched molded article of ultra-high-molecular-weight polypropylene having an intrinsic viscosity [.eta.] of at least 4 dl/g, which has a degree of orientation of not less than 0.930 when obtained as a degree of orientation by an X-ray diffraction half-width, two or more of peak positions (melting points) within the temperature region of not lower than 180.degree. C. when measured by a differential scanning calorimeter, and an amount of output energy of not less than 1 kgfm/g after 10-time repetition under a load of 50% of the breaking strength.

Abstract: A rope for traction of a double structure of a core member coated with a sheath member, in which said core member comprises a molecularly oriented shaped article of an ultrahigh molecular weight polyolefin, and said sheath member comprises a braid. The rope proposed herein is light in weight, floatable on water, easy to handle and excellent in safety to human bodies and weatherability.