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. 20, 2002
Filed:
Jul. 12, 1996
Johan Van Hunsel, Berchem, BE;
Paul Mortelmans, Mortsel, BE;
Agfa-Gevaert, Mortsel, BE;
Abstract
The present invention provides a concentrated dampening solution for use in a lithographic printing process having a pH between 3 and 6 and comprising a water-soluble organic solvent, a phosphate salt and a transparent pigment, characterized in that said transparent pigment is a modified silica in which the silica particles have a number average size of 0.003 to 0.100 &mgr;m and in which the silica particles are coated with chemically combined atoms of an amphoteric metal which forms an insoluble silicate at a pH between 5 and 12, said metal atoms being chemically bound through oxygen atoms to silicon atoms in the surface of said particles, and the amount of said metal being such that: Gram atoms M/Gram atoms Si=A/1250 to A/250000 where M is the metal and A is the surface area of the particles of the silica sol expressed in m /g.