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.:

US 7442725 B1

PDF
Full Text
Expired
Date of Patent:
Oct. 28, 2008

Filed:

Feb. 11, 2004
Applicants:

Wing Sum Vincent Kwan, Chicago, IL (US);

Jiandong Zhu, Aurora, IL (US);

Inventors:

Wing Sum Vincent Kwan, Chicago, IL (US);

Jiandong Zhu, Aurora, IL (US);

Assignee:

Sanford, L.P., Oak Brook, IL (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09D 11/00 (2006.01);
U.S. Cl.
CPC ...
Abstract

An improved color changing correction fluid is provided which includes either a volatile base or a volatile acid in combination with a color changing pH indicator, all in a water based fluid or system. As the fluid dries, the volatile base or acid evaporates along with the water and the pH color changing indicator changes from a colored state to a clear state. For white paper, a white pigment is utilized and therefore the fluid changes from a colored state to a white finished state as the solvent water and acid or base evaporates. Different color pigments can be utilized to match the color of the particular paper or substrate.


Find Patent Forward Citations

Kwan, Wing Sum Vincent. (2008). Color changing correction fluid (U.S. Patent No. 7442725). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/7442725

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

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