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. 07, 1999
Filed:
Dec. 30, 1997
Richard W Connelly, Rochester, NY (US);
James S Honan, Spencerport, NY (US);
Andrew M Howe, Watford, GB;
Eastman Kodak Company, Rochester, NY (US);
Abstract
A process for making a direct dispersion of a photographically useful material is discloses comprising: mixing (i) an aqueous phase comprising a gelatin solution and (ii) a liquid organic phase comprising a photographically useful material under conditions of high shear or turbulence to form a fine dispersion of the organic phase having an average particle size of less than 0.5 micron dispersed in the aqueous phase; wherein the gelatin solution comprises a mixture of a first gelatin having an isoelectric point pH of less than or equal to 5.2 and a second gelatin having an isoelectric point pH of greater than or equal to 6.0. In accordance with the invention, the use of blends of a first gelatin having an pI of less than or equal to 5.2, such as a conventional lime processed gelatin, and a second gelatin having an pI of greater than or equal to 6.0, such as an acid processed gelatin, in a direct photographic dispersion yields a substantial reduction in viscosity in comparison to the use of the first gelatin alone, which reduction is greater than would be expected by just using blends of the first gelatin with another relatively low pI gelatin having an equivalent inherent viscosity as the second gelatin. In accordance with preferred embodiments of the invention, relatively low levels of APO gelatin may be used partially replacing LPO gelatin in a dispersion formulation to obtain significant viscosity reduction while minimizing adverse effects which may be associated with the use of higher levels of acid processed gelatin.