| US 7,495,740 B2 | ||
| Birefringent marking | ||
| Robert Hammond-Smith, Hampshire (United Kingdom); John Patrick, Dorset (United Kingdom); Rodney Riddle, Dorset (United Kingdom); Matthias Kuntz, Seeheim-Jugenheim (Germany); Michael Ukelis, Riedstadt (Germany); Peter Schmitt, Wuerzburg (Germany); and Siegfried Schmitzer, Kuernach (Germany) | ||
| Assigned to Merck Patent GmbH, Darmstadt (Germany) | ||
| Appl. No. 10/527,693 PCT Filed Aug. 08, 2003, PCT No. PCT/EP03/08808 § 371(c)(1), (2), (4) Date Mar. 11, 2005, PCT Pub. No. WO2004/025337, PCT Pub. Date Mar. 25, 2004. |
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| Claims priority of application No. 02020293 (EP), filed on Sep. 11, 2002. | ||
| Prior Publication US 2006/0023157 A1, Feb. 02, 2006 | ||
| Int. Cl. G02F 1/13 (2006.01) | ||
| U.S. Cl. 349—187 | 33 Claims |
| 1. A method of preparing a birefringent marking comprising:
printing a polymerisable liquid crystal material directly onto at least one surface of a reflective substrate; and
polymerising the liquid crystal material,
whereby a birefringent marking is formed on said reflective substrate,
wherein said polymerizable liquid crystal material is printed onto the reflective substrate by screen printing, offset printing,
dry offset printing, reel-to-reel printing, letter press printing, gravure printing, rotogravure printing, flexographic printing,
intaglio printing, pad printing, heat-seal printing, ink-jet printing, or printing by means of a stamp or printing plate,
and
printing of said polymerizable liquid crystal material onto the reflective substrate induces or enhances spontaneous alignment
of the polymerizable liquid crystal material on said reflective substrate.
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