3m Innovative Properties Company

Mark D Nachbor

Christopher Stewart Lyons

Kenneth A Epstein

Robert J Fleming

Stephen P Maki

Timothy J Gardner

Kenneth L Smith

Gerald M Benson

James C Coderre

Mark A Strobel

Donald J McClure

Paul Edward Humpal

John R Park

The present invention provides a method of modifying the surface of a polymeric substrate, e.g., to improve the wettability of the polymer film surface and/or alter the metal adhesion properties of the surface of the substrate by exposing the substrate to a flame. The flame is supported by an oxidizer and fuel mixture that includes an effective amount, for modifying the polymeric substrate, of at least one sulfur-containing compound that functions as a fuel substitute. In addition, substrates are provided that have increased wettability or increased metal adhesion performance.

Flame-treating process

Retroreflective sheeting includes a body layer having a structured surface with recessed faces and top surfaces, the recessed faces forming cube corner cavities. The recessed faces have a high specular reflectivity, while the top surfaces have a low specular reflectivity. In some embodiments a substantially continuous film of reflective material covers the structured surface, and a masking substance is provided over the reflective material at the top surfaces. Alternatively, the top surfaces are given a non-smooth surface finish so that the film of reflective material on those portions has a diffuse reflectivity. In other embodiments the film of reflective material is discontinuous, disposed selectively on the recessed faces and not on the top surfaces. A cover layer is also provided, and can bond at least to the top surfaces. Keeping the top surfaces substantially free of reflective material inhibits corrosion and can enhance the bond integrity. The top surfaces are preferably flat, and diffusely reflective to enhance the daytime whiteness of the sheeting.

Cube corner cavity based retroreflectors and methods for making same

The present invention is a display apparatus that provides protection against damage for a metallic layer. The display apparatus includes a light modulating layer, a polarizer, and a light directing film. The light directing film includes a prismatic structure having two sides, where one side includes saw tooth formations having tilted surfaces and a metal layer on the side of the prismatic substrate having the saw-tooth formations. A tilt angle of the tilted surfaces offsets an optimal viewing angle for the display from a glare angle for the display. In a first embodiment of the invention, the light directing film of the display apparatus further includes an inorganic protective layer formed on the metal layer, wherein the inorganic protective layer inhibits molecular transfer to the metal layer and balances the color of reflected and transmitted light. The light directing film further includes a pressure sensitive adhesive layer between a polarizer and the inorganic protective layer. Alternatively, the light directing film of the display apparatus of the present invention includes a polymer protective layer formed over the metal layer to protect the metal layer from damage. The light directing film also includes a diffuse adhesive layer formed over the polymer layer, attached to the polarizer. The polymer protective layer protects the metal layer from the adhesive layer. The display apparatus may include both the inorganic protective layer and the polymer protective layer, in one embodiment.

Display apparatus with corrosion-resistant light directing film

Growing community of inventors

Plymouth, MN, United States of America

Mark D Nachbor