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:
Jul. 15, 2014
Filed:
Feb. 24, 2012
Deepak Mahulikar, Madison, CT (US);
Yuhu Wang, Santa Rosa, CA (US);
Ken A. Delbridge, Chandler, AZ (US);
Gert R. M. Moyaerts, Phoenix, AZ (US);
Saeed H. Mohseni, Sylvania, OH (US);
Nichole R. Koontz, Mesa, AZ (US);
Bin HU, Chandler, AZ (US);
Liqing Wen, Mesa, AZ (US);
Deepak Mahulikar, Madison, CT (US);
Yuhu Wang, Santa Rosa, CA (US);
Ken A. Delbridge, Chandler, AZ (US);
Gert R. M. Moyaerts, Phoenix, AZ (US);
Saeed H. Mohseni, Sylvania, OH (US);
Nichole R. Koontz, Mesa, AZ (US);
Bin Hu, Chandler, AZ (US);
Liqing Wen, Mesa, AZ (US);
Fujifilm Planar Solutions, LLC, Adrian, MI (US);
Abstract
A method for producing and using an ultrapure colloidal silica dispersion is disclosed. The ultrapure colloidal silica dispersion has less than 200 ppb of each trace metal impurity disposed therein, excluding potassium and sodium, and less than 2 ppm residual alcohol. The method comprises dissolving a fumed silica in an aqueous solvent comprising an alkali metal hydroxide to produce an alkaline silicate solution, removing the alkali metal via ion exchange to generate a silicic acid solution, adjusting temperature, concentration and pH of said silicic acid solution to values sufficient to initiate nucleation and particle growth, and cooling the silicic acid solution at a rate sufficient to produce the colloidal silica dispersion.