Polymeric article having improved hydrophilicity and a method of making the same

DETAILED DESCRIPTION The present invention provides a new hydrophilic article that demonstrates extraordinary water-spreading effects.
In brief summary, the article of the invention comprises a polymeric sheet having metal oxide particles dispersed in a polymeric material.
The polymeric sheet has a first major surface and an interior, and on the first major surface of the polymeric sheet there is a higher ratio of metal to carbon atoms relative to the interior thereof.
The present invention also provides a new method of making an article having improved water-spreading effects.
The method comprises: providing a polymeric sheet that has a first major surface and comprises metal oxide particles in a polymeric binder; and treating the first major surface of the sheet so as to remove polymeric binder therefrom to increase exposure of the metal oxide particles.
The method of the invention may be utilized in providing improved water-spreading performance to the known hydrophilic compositions mentioned above which contain metal oxide particles dispersed in a polymer.
Accordingly, the disclosures of the above-discussed documents disclosing such are incorporated herein by reference.
The present invention also provides a new 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 transparent water-spreading layer has first and second major surfaces and an interior and comprises a polymeric material that has metal oxide particles dispersed therein.
The first major surface of the water-spreading layer represents the exposed surface of the retroreflective article and possesses a higher ratio of metal to carbon atoms relative to the interior of the water-spreading layer.
The second major surface of the water-spreading layer is juxtaposed against the first major surface of the retroreflective sheeting.
The present invention is an improvement over known hydrophilic materials