John C Helfrick

Author:

John F. Helfrick

ISBN #:

0721629687

US Patent:

20070111314, May 17, 2007

Filed:

Nov 8, 2005

Appl. No.:

11/269093

Inventors:

Lufei Lin - San Diego CA, US
John Helfrick - San Diego CA, US
Sundar Vasudevan - Corvallis OR, US
LeAnn Bell - Corvallis OR, US
Mark Wisnosky - San Diego CA, US

International Classification:

G01N 33/24

US Classification:

436027000

Abstract:

A method for tagging an ink with an isotopic tagging composition is provided. The method includes tagging the ink with a tagging composition having an artificial abundance of at least one isotope of an element to produce an authentic ink having an artificial abundance of the at least one isotope of the element which exceeds a natural abundance thereof in the authentic ink. A method for authenticating unidentified ink samples by comparing isotope abundances and/or abundance ratios in the unidentified ink samples with isotope abundances and/or abundance ratios in authentic inks tagged with isotopic tagging compositions is also provided. The method also includes tagging a pigment-based ink with trityl-protected thiol additives and methods for identifying inks containing the same.

US Patent:

20140305606, Oct 16, 2014

Filed:

Apr 15, 2013

Appl. No.:

13/863098

Inventors:

John L. Stoffel - San Diego CA, US
John C. Helfrick - San Diego CA, US
Silke Courtenay - Temecula CA, US

Assignee:

HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P. - Fort Collins CO

International Classification:

D21H 21/16
D21H 17/14
D21H 21/38

US Classification:

162161, 10628724, 1062152, 106 1505, 162158, 162175

Abstract:

A sizing composition includes from about 3 kg/ton to about 15 kg/ton of calcium propionate, an additive, and a balance of water. The additive is selected from the group consisting of starch, an optical brightener, a biocide, a defoamer, a surface size agent, a wet strength additive, and combinations thereof. The sizing composition has a pH ranging from 7 to 8.