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:
Jun. 02, 1987
Filed:
Nov. 05, 1984
Firma Carl Freudenberg, Weinheim, DE;
Abstract
A method of making an electrically-conductive floor covering presses a polymeric bottom layer into apertures in a top layer having a higher flow viscosity than the bottom layer, the pressure also bonding the layers together. The bottom layer contains from about 3% to about 80% by weight carbon black or graphite for electrical conduction; the top layer contains not more than about 0.5% thereof. The apertures in the top layer are at least 1 mm in diameter and regularly or irregularly spaced from the next adjacent aperture from about 2 mm to about 40 mm, the area of the apertures not exceeding 40% per unit area of the top layer. The dark color of the bottom layer resulting from its carbon black or graphite content therefore need not significantly affect the appearance of the top layer, but provides electrical conductivity through the apertures.