3m Innovative Properties Company

Minnesota Mining and Manufacturing Company

Tzu-Li J Huang

James C Coderre

Kenneth L Smith

Dong-Wei Zhu

Walton J Hammar

Bettie C Fong

John H Ko

David A Kaisaki

Mirian D Nave

A retroreflective articlehas a body portionand a multitude of cube-corner elementsthat project from a rear sideof the body portion. The body portionincludes a body layerthat contains a light-transmissible polymeric material having an elastic modulus less than 7&#xd7;10pascals. The cube-corner elementscontain a light transmissible polymeric material having an elastic modulus greater than 16&#xd7;10pascals. A retroreflective article of this construction can be highly flexed while maintaining good retroreflective performance.

Flexible cube-corner retroreflective sheeting

Flexible cube-corner retroflective sheeting

An article is disclosed that has a patterned surface containing alternating hydrophobic and hydrophilic surface regions. The hydrophobic regions may be sufficiently narrow such that under dew conditions moisture accumulated on the hydrophobic region migrates to the hydrophilic region, thus preventing the accumulation of water droplets. In frost conditions, the hydrophobic region remains relatively frost-free, thus maintaining at least partial transparency of the surface. Inorganic oxide particles on the surfaces of the hydrophobic regions may provide abrasion resistance. A method for making the patterned surfaces is disclosed in which a treatment removes organic binder to expose inorganic oxide particles at the surface of the hydrophilic regions.

Patterned article having alternating hydrophilic and hydrophobic surface regions

A retroreflective article has a body portion and a multitude of cube-corner elements that project from a rear side of the body portion . The body portion includes a body layer that contains a light-transmissible polymeric material having an elastic modulus less than 7&times;10 pascals. The cube-corner elements contain a light transmissible polymeric material having an elastic modulus greater than 16&times;10 pascals. A retroreflective article of this construction can be highly flexed while maintaining good retroreflective performance.

A retroreflective article 10 has a body portion 14 and a multitude of cube-corner elements 12 that project from a rear side 20 of the body portion 14. The body portion 14 includes a body layer 18 that contains a light-transmissible polymeric material having an elastic modulus less than 7.times.10.sup.8 pascals. The cube-corner elements 12 contain a light transmissible polymeric material having an elastic modulus greater than 16.times.10.sup.8 pascals. A retroreflective article of this construction can be highly flexed while maintaining good retroreflective performance.

A hydrophilic polymeric article has metal oxide particles dispersed throughout a polymeric binder material. A major surface of the polymeric material is treated so as to remove polymeric binder to provide a higher ratio of metal to carbon atoms on the major surface of the polymeric article relative to its interior. The polymeric article provides extraordinary water-spreading effects on the major surface, making the article particularly suitable for use as a surface covering on a retroreflective sheeting.

Polymeric article having improved hydrophilicity and a method of making

A silica-based water-spreading coating having surfaces of silica particles coated with a metal oxide. The metal comprises aluminum, gallium, germanium, tin, indium, arsenic, antimony or vanadium. The water-spreading coating may be applied to a retroreflective sheeting on a traffic sign.

Durability improved colloidal silica coating

A retroreflective article 10 has a body portion 14 and a multitude of cube-comer elements 12 that project from a rear side 20 of the body portion 14. The body portion 14 includes a body layer 18 that contains a light-transmissible polymeric material having an elastic modulus less than 7.times.10.sup.8 pascals. The cube-corner elements 12 contain a light transmissible polymeric material having an elastic modulus greater than 16.times.10.sup.8 pascals. A retroreflective article of this construction can be highly flexed while maintaining good retroreflective performance.

The present invention provides improved, flexible retroreflective articles based upon an optically clear, aliphatic polyurethane polymer. The aliphatic polymer has a plurality of hard chain segments of the formula

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Woodbury, MN, United States of America

Tzu-Li J Huang