Method for producing iridescent solid nanocrystalline cellulose films incorporating patterns
US8398901B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 2009 |
| Grant date | Mar 19, 2013 |
| Priority date | — |
| Expiry date | Dec 23, 2031 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB42D25/391
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A new method to produce solid nanocrystalline cellulose (NCC) films containing patterns by differential heating of aqueous suspensions of NCC has been discovered. When acid-form NCC suspensions are dried by heating to temperatures above 50° C., darkening of the NCC can occur, while neutral forms of NCC can produce iridescent chiral nematic films by heating to temperatures up to 105° C. Placing materials of different thermal conductivity beneath the container containing an evaporating NCC suspension results in watermark-like patterns of different iridescent color imprinted within the film structure. Other colloidal rod-like particles can be employed in place of nanocrystalline cellulose (NCC), for example chitin or chitosan.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.