Crotonic acid polymer coated substrates for producing optically variable products
US5928781A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 11, 1997 |
| Grant date | Jul 27, 1999 |
| Priority date | — |
| Expiry date | Nov 11, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31797
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method is provided for forming a dissolvable or strippable polymeric release coating on the surface of flexible web, forming an overcoated metallized or optically variable layer on said release coating, and stripping or dissolving the release coating to release the overcoated layer. The release coating comprises a polymer of crotonic acid which is soluble in a solvent such as acetone. The polymer may be a copolymer of crotonic acid and at least one vinyl ester such as vinyl acetate. The release coating may be formed during an in-line process which begins with drawing the flexible web from a molten polymeric material. The methods are particularly advantageous for forming optically variable flakes and multilayered optically variable devices.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.