Patent · US Active

Composite crystal colloidal array with photochromic member

US8641933B2 · kind B2 · utility

24Cited by

34References

27Claims

0Family size

Assignee

PPG Industries Ohio, Inc. · US

Inventors

Sean Purdy · Cincinnati, US
Jessica Williamson · Wilder, US
Anil Kumar · Dehradun, IN
Noel R. Vanier · Wexford, US
Wei Wang · Palo Alto, US
Shan Cheng · Pittsburgh, US
Xiangling Xu · Pittsburgh, US

Key dates

Filing date	Sep 23, 2011
Grant date	Feb 4, 2014
Priority date	—
Expiry date	Dec 2, 2031

Classification

Technology area (CPC B)Performing Operations; Transporting
CPC primaryB42D2035/24
WIPO fieldOther consumer goods
WIPO sectorOther fields

Abstract

The invention includes a composite material for use in a security device including a radiation diffracting component that exhibits a first optical effect and a photochromic component that exhibits a second optical effect. The composite material is particularly suited for use in authenticating articles, such as currency.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.