Preparation of low viscosity small particle photographic dispersions in gelatin
US5135844A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 1991 |
| Grant date | Aug 4, 1992 |
| Priority date | — |
| Expiry date | Feb 12, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S516/922
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The invention is generally accomplished by utilization of a surfactant for very small particle photographic dispersions. Three types of such surfactants that have been identified are as follows: PA1 Type A--Surfactant comprising 6 to 22 carbon atom hydrophobic tail with one or more attached hydrophilic chains comprising at least 8 oxyethylene and/or glycedyl ether groups that may or may not be terminated with a negative charge such as a sulfate group. PA1 Type B--Block oligomeric surfactants comprising hydrophobic polyoxypropylene blocks (A) and hydrophilic polyoxyethylene blocks (B) joined in the manner of A--B--A, B--A--B, A--B, (A--B).sub.n .tbd.G.tbd.(B--A), or (B--A).sub.n .tbd.G.tbd.(A--B).sub.n, where G is a connective organic moiety and n is between 1 and 3. PA1 Type C--Sugar surfactants, comprising between one to three 6 to 22 carbon atom hydrophobic tail with one or more attached hydrophilic mono or oligosaccharidic chains that may or may not be terminated by a negatively charged group such as a sulfate group. The preferred colloid chemical criterion of the photographic dispersion material in this invention is that they are formed with particle diameters between about 5 n…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.