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:
Dec. 24, 2002
Filed:
Apr. 27, 2001
John L. Stoffel, San Diego, CA (US);
Anne M. Kelly-Rowley, San Diego, CA (US);
Keshava A. Prasad, San Marcos, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An inkjet ink is provided that has a greater organic content than prior art inks. However, it is not simply enough to increase the organic content; other factors must be considered as well. These include controlling viscosity and surface tension, as well as maintaining acceptable drytime. An inkjet ink composition that evidences reduced outgassing and reduces paper cockle and curl comprises about 25 to 50 wt % of one or more organic co-solvents, has a viscosity of 10 cp or less, and has a surface tension of 40 dyne/cm or less. Advantageously, using a higher solvent ink reduces cockle and curl. Cockle and curl are also reduced as the water content of the ink is reduced. The present invention uses the higher solvent inks in combination with underprinting. In underprinting, a fixer solution is first “printed” on the print medium, followed by printing the inkjet ink thereon. There is a synergism to this combination. Together, weaknesses of both approaches are addressed. The advantages are a longer life pen, due to the reduction of outgassing of the ink, and reduced cockle and curl.