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# c12) United States Patent 

# Vincent et al. 

# (54) LATEXES AND INK-JET INKS PREPARED USING BLOCKED ACID MONOMERS 

(75) Inventors: Kent D. Vincent, Cupertino, CA (US); Sivapackia Ganapathiappan, Los Altos, CA (US) 

(73) Assignee: Hewlett-Packard Development Company, L.P., Houston, TX (US) 

( *) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by O days. 

(21) Appl. No.: 10/741,536 

(22) Filed: Dec. 19, 2003 

## (65) Prior Publication Data 

US 2005/0137319 Al Jun. 23, 2005 

(51) Int. Cl. 

<img src='content_image/939077.jpg'>

(52) U.S. Cl. .................. 106/31.25; 106/31.6; 524/547; 524/556; 524/599; 524/609; 524/610; 524/612; 524/853 

(58) Field of Classification Search ............. 106/31.25, 106/31.6; 524/547, 556, 599, 609, 610, 612, 524/853 See application file for complete search history. 

## (56) References Cited 

5,708,095 A * 1/1998 Grezzo Page et al. ...... 525/301 

## U.S. PATENT DOCUMENTS 

<img src='content_image/939085.jpg'>

# (IO) Patent No.: US 7,371,273 B2 

# May 13, 2008 (45) Date of Patent: 

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## FOREIGN PATENT DOCUMENTS 

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* cited by examiner 

Primary Examiner-Kelechi C. Egwim 

## (57) ABSTRACT 

The present is drawn to the use of blocked acid monomers for the incorporation of highly acidic groups, such as strong acids and multiple acids, on the surface oflatex particles via emulsion polymerization. In accordance with this, a method of forming latex particulates having high charge density surfaces can comprise the steps of preparing a monomer emulsion including an aqueous phase and an organic mono› mer phase, wherein the organic monomer phase includes at least one blocked acid monomer; polymerizing the organic monomer phase to form blocked acid latex particulates dispersed in the aqueous phase; and unblocking the blocked acid latex particulates to form acidified latex particulates. 

US007371273B2 

## 9 Claims, No Drawings 

