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:
May. 02, 2000
Filed:
Dec. 18, 1998
Applicant:
Inventor:
Gerhard Lugert, Nurnberg, DE;
Assignee:
A. W. Faber-Castell, Stein, DE;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C09D / ;
U.S. Cl.
CPC ...
106 3109 ; 106 3111 ;
Abstract
The invention relates to a colored pencil lead having an essentially water-free base material that is at least partially water-soluble or can be suspended in water, which base material contains at least one dye and at least one reactant present in a solid form, wherein this reactant, when in a watery solution, causes a change in color in the dye.