Abstract: Before Au-plating onto the metallic surface of an electronic part, Ni-plating and then Co-plating are applied to form a primer coating for Au-plating. But in the steps of Ni and Co-platings, hydrogen gas produced during the plating is occluded into a plating layer. On the other hand, when a pellet connected onto an Au-plated metal, an Au-Si alloy is formed, but hydrogen gas in the plating layer remains as voids in the Au-Si alloy during a subsequent heating step of the electronic part, resulting in a serious defect. This invention of a plating method is characterized by annealing after Au-plating of an electronic part to eliminate the residual gas.

Abstract: A crystalline polymeric whisker comprising repeating units derived from a compound selected from the group consisting of p-oxybenzoyl and 2-oxy-6-naphthoyl, which has high elasticity and tenacity as well as good heat resistance.

Abstract: Crosslinked polyethylene filaments made of polyethylene having an average molecular weight of not less than 4.times.10.sup.5, which are stretched and crosslinked by irradiation of radioactive rays and have a strength of not less than 20 g/d and an initial modulus of not less than 400 g/d.

Abstract: A process for producing a drawn product of a crystalline polymer having tenacity and high modulus, which comprises compressing a gel-like material prepared from a solution of a crystalline polymer in a solvent (i.e. a gel-like sheet material (A) consisting of gel-like particles of a crystalline polymer and a solvent which is prepared by cooling a solution of a crystalline polymer in a solvent, or a gel-like film material (B) which is prepared by casting a solution of a crystalline polymer in a solvent) at a temperature lower than the temperature at which the gel-like material is dissolved, whereby removing a part of the solvent contained in the gel-like material, and drawing the compressed material, preferably using a drawing die. The drawn product is particularly useful as a tension member for optical fiber cable.

Abstract: Stretched filaments of high strength and high modulus being made of polyethylene of a weight average molecular weight of not less than 3.times.10.sup.6 and having a strength of not less than 50 g/d and an initial modulus of not less than 1,500 g/d, the long period structure being substantially not observed, which are prepared by spinning a dilute solution of said polyethylene and stretching the resultant gel-like filaments in multi-stages until the long period structure becomes substantially not observed.

Abstract: A process for preparing a biaxially stretched film of polyamide blend, which comprises (1) extruding a polyamide blend in melt to make an unstretched film and (2) stretching the unstretched film first in a machine direction with a stretch speed of about 40,000 to 60,000,000 %/minute in a draw ratio of about 2 to 6 and then in a transverse direction with a stretch speed of about 500 to 100,000 %/minute in a draw ratio of about 2 to 6, or (2') stretching the unstretched film first to make a uniaxially stretched film having a plane orientation index of about 0.6 to 1.