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:
Aug. 14, 2001
Filed:
Sep. 15, 1995
John F. Krumwiede, Cheswick, PA (US);
Anthony V. Longobardo, Butler, PA (US);
Larry J. Shelestak, Bairdford, PA (US);
David R. Haskins, Gibsonia, PA (US);
PPG Industris Ohio, Inc., Cleveland, OH (US);
Abstract
The present invention provides a glass composition having a neutral gray color and a luminous (visible) transmittance within a range that allows the glass to be used as privacy glazing in a vehicle. The glass of the present invention has a standard soda-lime-silica flat glass base composition and uses iron, cobalt and selenium, and optionally nickel, as the colorants. It has also been found that a nickel-free, neutral gray colored glass with a luminous transmittance (C.I.E. illuminant A) of up to 40% at a thickness of 3.9 millimeters may be attained by using as colorants: 0.59 to 0.99 wt. % of the total glass Fe,O,(total iron), no greater than 0.30 wt. % FeO; 60 to 180 PPM CoO and 5 to 30 PPM Se. It has been found that a nickel-bearing, neutral gray colored glass with a luminous transmittance (C.I.E. illuminant A) of up to but less than 40% at a thickness of 3.9 millimeters may be attained by using as colorants: 0.35 to 1.1 wt. % of the total glass Fe,O,(total iron), no greater than 0.30 wt. % FeO; 60 to 180 PPM CoO; 1 to 30 PPM Se; and 25 to 550 PPM NiO.