3M Innovative Properties Company

Minnesota Mining and Manufacturing Company

Kenneth M White

Vera L Lightle

Lee A Pavelka

James C Coderre

Cecil V Francis

John F Dreyer

Paul E Marecki

Richard J Kuo

Tadesse G Nigatu

Roberta E Harelstad

Mathias Detjen

Brian W Dunne

A tamper-indicating printable sheet. A preferred embodiment of the invention provides a tamper-indicating printable sheet comprising a retroreflective layer comprising a plurality of microbeads partially embedded in an inkjet receptive beadbond layer; and a reflector layer between one of the microbeads and the inkjet receptive beadbond layer. The present invention provides a method of making a tamper-indicating printable sheet.

Tamper-indicating printable sheet for securing documents of value and methods of making the same

A durable colored article having fluorescent properties comprises a substantially solventless polyvinyl chloride matrix, a thioxanthene fluorescent dye, and a secondary or tertiary hindered amine light stabilizer having a molecular weight less than about 1000 grams/mole. The invention has the advantage in that it provides a flexible polyvinyl chloride film that exhibits durable fluorescent colors.

Stabilization of fluorescent dyes in vinyl articles using hindered amine light stabilizers

Stabilization of fluorescent dyes in vinyl chloride articles using hindered amine light stabilizers

Stabilization of fluorescent dyes in vinyl articles using hindered amine

Dual axis retroreflective articles and methods of using them are disclosed. The retroreflective articles may combine dual axis retroreflection with three axis retroreflection to provide a steady glow due to the three axis retroreflective portions of the article and also provide intermittent or flashing retroreflection as the plane of retroreflection from the dual axis retroreflector passes through or near the light source. The retroreflective articles may also include dual axis retroreflective structures in combination with sparkling reflective structures, as well as dual axis retroreflective structures in combination with both three axis retroreflective structures and sparkling reflective structures. Methods of use include moving the dual axis retroreflective structures to obtain intermittent or flashing retroreflection.

Dual axis retroreflective articles

This invention provides an optical medium and a process therefor wherein the medium exhibits third order nonlinear optical response and comprises a polymer with pendant groups having delocalized pi-electron character forming a charge transfer complex with dopant molecules. The optical medium is useful in optical devices, such as optical switches or light modulation devices as a component or as a coating. In other aspects, novel polymers and polymer complexes are disclosed.

Polymeric charge transfer complexes for nonlinear optical applications

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Oakdale, MN, United States of America

Kenneth M White