Use of gelatin-grafted and case-hardened gelatin-grafted polymer particles for relief from pressure sensitivity of photographic products
US5026632A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 1990 |
| Grant date | Jun 25, 1991 |
| Priority date | — |
| Expiry date | Mar 22, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/162
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
It has been shown by Photon Correlation Spectroscopy that when additional hardener is added to below saturation gel-grafted polymer particles, the gel layer shrinks due to hardening, as there is no free gel left in solution. In films, such case-hardened gelatin-grafted soft polymer particles can act as highly elastic stress absorbing fillers. This is because the dry case-hardened shell is expected to form a thin hard shell around the soft polymer particles. It is shown that gelatin-grafted soft polymer particles and case-hardened gelatin-grafted soft polymer particles, incorporated in the emulsion layers of pressure sensitive photographic products, produce coatings with highly reduced pressure sensitivity without any developability or delamination concerns. In this invention the case-hardened gelatin-grafted polymer particles are preferred over the simple gelatin-grafted material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.