Polymeric article having improved hydrophilicity and a method of making the same
AssigneeMinnesota Mining and Manufacturing Company
InventorsTzu-Li J. Huang, David A. Kaisaki
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Abstract
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.
Claims52
A hydrophilic polymeric article that comprises:
- a polymeric sheet that is about 5 micrometers or more thick and that has 5 to 90 weight percent of metal oxide particles dispersed in a polymeric material, the polymeric sheet having a first major surface and an interior, there being a higher ratio of metal to carbon atoms on the first major surface of the polymeric sheet relative to the interior thereof.
A retroreflective article, which comprises:
- (a) a retroreflective sheeting having first and second major surfaces;
- and
- (b) a transparent water-spreading layer disposed on the first major surface of the retroreflective sheeting, the water-spreading layer comprising a polymeric material that has metal oxide particles dispersed therein, the water-spreading layer having first and second major surfaces and an interior, the second major surface of the water-spreading layer being juxtaposed against the first major surface of the retroreflective sheeting, and the first major surface of the water-spreading layer having a higher ratio of metal to carbon atoms relative to the interior of the water-spreading layer.
A hydrophilic polymeric article that comprises:
- a polymeric sheet that has 5 to 90 weight percent of metal oxide particles dispersed in a polymeric material, the polymeric sheet having a first major surface and an interior, there being a higher ratio of metal to carbon atoms on the first major surface of the polymeric sheet relative to the interior thereof.
Dependencies are inferred from the claim text.