Abstract: A torque transmission unit according to the invention comprises a bolt (1) which has curved outer peripheral surfaces (3) with a peripheral outline consisting of circular arcs circumscribing the sides of a square (.alpha.), respectively, and a socket wrench (2) which has curved inner peripheral surfaces (4) with a peripheral outline consisting of circular arcs circumscribing the sides of a square (.beta.), respectively. The curved inner peripheral surfaces (4) of the socket wrench (2) are brought into contact with the curved outer peripheral surfaces (3) of the bolt (1) and slid thereon by rotating the socket wrench (2). As a result, clamping can be performed with the axis of rotation of the wrench (2) made to coincide with that of rotation of the bolt (1). By virtue of this structure, any corner portion of the bolt (1) is prevented from being rounded.

Abstract: Laminated polyester film having a base layer of biaxially oriented polyethylene terephthalate or polybutylene terephthalate is laminated directly by heat sealing and without the use of any intervening adhesive with a crystalline butylene terephthalate or hexylene terephthalate copolyester blended with from about 10 to 40 weight % of a polyethylene terephthalate or polybutylene terephthalate, said copolyester containing about from 50 to about 80 mole % of terephthalic acid units based on the total acid component of the copolyester.

Abstract: An acrylic fiber having excellent antistatic properties is obtained by mixing a polymer (A) consisting mainly of acrylonitrile with a copolymer (B) consisting mainly of a polyetherpolyester block copolymer consisting of a polyester and compound represented by the general formula (1): ##EQU1## (wherein each of m and n is O or a positive integer, wherein 25 .ltoreq. m + n .ltoreq. 1000, and m .gtoreq. 10).

Abstract: Fiber- and film-forming composition comprising a linear synthetic polyester together with antimony-containing particles, present in an amount of from 0.02 to 1.0% by weight of the composition. The content of elemental antimony in the antimony-containing particles is from 15 to 70% of the weight of the particles.

Abstract: A process for preparing a polyester predominantly comprised of the units derived from terephthalic acid and butanediol-1,4 is provided. The esterification or transesterification is performed in the presence of minor amounts of a catalyst combination comprising an organo-titanium compound and an organo-tin compound. The undesirable formation of tetrahydrofuran can be avoided or minimized.