METHOD FOR RAPIDLY EVALUATING DURABILITY OF POLYETHYLENE RESIN TUBE AND METHOD FOR RAPIDLY DECIDING UNDEFECTIVE OR DEFECTIVE OF POLYETHYLENE FOR TUBE

摘要

PROBLEM TO BE SOLVED: To provide a method for evaluating durability of a polyethylene resin gas tube and rapidly deciding undefective or defective of a polyethylene resin for a gas tube. ;SOLUTION: In the case of satisfying following paragraphs (1) and (2) by a polyethylene resin by measuring a molecular weight distribution and a branched chain density and identifying a length of a branched chain of the resin for constituting a gas tube, durability of the tube is decided to be non- defective. (1) The resin contains 5.5 wt.% or more of a high molecular weight fraction of an entirety in the case that a molecular weight in terms of a polystyrene is 1,000,000 (10⁶) or more when o-dichlorobenzene at 140°C is used as a GPC solvent, and (2) the fraction in which the molecular weight in terms of a polystyrene is 1,000,000 (10⁶) or more contains 4.0 or more per 1,000 pieces of carbon atoms of a 4-more C branched chain in average.;COPYRIGHT: (C)1999,JPO