| abstract |
Stable photographic coating compositions comprising a polymer latex are prepared by mixing an aqueous solution comprising gelatin with a latex dispersion of a polymer of the formula(A)x(B)y(C)zwhere A and B are formed from nonionic monomers, C is formed from anionic monomers, and x, y and z are monomer weight fractions where x=0 to 1.0, y=0 to 1.0, x+y=about 0.98 to 1.0, and z=0 to about 0.02, wherein A, B, x and y are such that latex dispersions of polymers of the formula (A)x(B)y have calcium ion critical coagulation concentrations of less than 80 mM Ca+2 in gelatin solutions, wherein the gelatin of the aqueous solution mixed with the latex dispersion comprises a gelatin of low calcium ion content such that the coating composition has a calcium Ca2+ concentration of less than 2 mM. The method of the invention allows for the preparation of aqueous gelatin coating solutions comprising latex dispersions of polymers which are unstable in the presence of calcium ions. The process can yield dispersions and photographic elements with superior attributes, including dispersion stability, and photographic color reproduction, image preservability, and abrasion resistance. |