The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 16, 1986
Filed:
Jul. 16, 1985
Mitsui Petrochemical Industries, Ltd., Tokyo, JP;
Abstract
Stretched articles of ultrahigh-molecular-weight polyethylene are prepared by melt-kneading a mixture of ultrahigh-molecular-weight polyethylene with a paraffinic wax having a melting point of 40.degree. to 120.degree. C. and a weight average molecular weight of at least 230 but less than 2000 in a screw extruder while maintaining the temperature of the mixture at 180.degree. to 280.degree. C. The molten mixture is melt-extruded through a die at a temperature of 180.degree. to 300.degree. C. under a draft condition of a draft ratio of less than 2 or in the absence of a draft and the resulting unstretched extrudate is cooled to solidify it. The unstretched solidified extrudate is than subjected to a stretching treatment in a heated liquid medium which is a solvent for the paraffinic wax at a temperature of 60.degree. to 140.degree. C. at a particular stretch ratio. Stretch shaped articles of ultrahigh-molecular-weight polyethylene having high tensile strength and modulus of elasticity are produced uniformly and reproducibly. The stretched shaped articles are substantially free from stretching uneveness. Examples of the paraffinic wax include n-alkanes having at least 22 carbon atoms.