Patent Number: 6,251,505

Title: Backlit display composite film

Abstract: A composite film is described which consists of a primary unfilled polyester layer and a secondary polyester layer containing from 1 to 8% by weight, based on the weight of the secondary polyester layer, of finely divided silica particles having a volume weighted mean particle size diameter D[4,3] of from 2.3 to 6.2 micrometers. The composite film is used in backlit displays such as illuminated signboards and provides uniform light transmission while maintaining the same strength of illumination at all points over the area of the display.

Inventors: Rakos; Karl (Durham, GB), Mills; Paul David Alan (Durham, GB), Logan; Moira (Teeside, GB), Brabbs; Noel Stephen (Luxembourg, GB)

Assignee: E. I. du Pont de Nemours and Company

International Classification: B32B 27/36 (20060101); C08J 7/00 (20060101); C08J 7/04 (20060101); B32B 007/02 ()

Expiration Date: 06/26/2018