Photographic negative base for self-developing film packs
US4312937A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 1980 |
| Grant date | Jan 26, 1982 |
| Priority date | — |
| Expiry date | Apr 11, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31902
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
This disclosure relates to production of a photographic film assembly substantially free of optical pinholes for use as a base for negatives in self-developing film packs. The assembly comprises a paper layer and first and second layers of polyolefin adhered to opposite sides of the paper layer. The paper layer has a caliper of about 2 mils to about 4.5 mils and a basis weight of about 55 g/m.sup.2 to about 125 g/m.sup.2. The first and second polyolefin layers each have a layer weight of about 10 g/m.sup.2 to about 48 g/m.sup.2. Carbon black is uniformly dispersed in at least two out of the three layers. The total amount of carbon black in the assembly is about 2.5 g/m.sup.2 to about 4.0 g/m.sup.2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.