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:
Nov. 17, 1998
Filed:
Oct. 06, 1995
Koujiro Takano, Hyogo-ken, JP;
Mamoru Ishii, Hyogo-ken, JP;
Masaharu Mito, Yamaguchi-ken, JP;
Satoshi Akiyama, Chiba-ken, JP;
Mitsui Chemicals, Inc., Tokyo, JP;
Abstract
A polypropylene-laminated steel sheet is provided which is less liable to cause whitening on receiving impact shock and is superior in resistance to corrosion. A process for producing the polypropylene-laminated steel sheet is also provided. The polypropylene-laminated steel sheet comprises, at least on one side of the steel sheet, a layer (A) of modified polypropylene grafted with an unsaturated carboxylic acid, and, if desired, a layer (B) of polypropylene formed additionally on the layer (A), the modified polypropylene of the layer (A) and the polypropylene of the layer (B) having crystallinity of not more than 55%. The modified steel sheet is produced by the process which comprises melt-extruding and laminating a modified polypropylene (A) grafted with an unsaturated carboxylic acid on at least one side of a preheated steel sheet, and, if desired, a polypropylene (B) further thereon, and cooling the steel sheet, the modified polypropylene (A) and the polypropylene (B) together at a cooling rate of not less than 20.degree. C./sec at least in the temperature range of from 100.degree. C. to 55.degree. C.