Patent ID: 7847033
Filing Date: 2010-12-07
Classification: C08F,C08L,C09K,G02F

Abstract:
1. A film for use in a suspended particle device (SPD), said film comprised of a cross-linked matrix polymer having a plurality of droplets of a liquid light valve suspension distributed therein, said film being formed with the use of an emulsifier, said emulsifier being a separate non-crosslinkable emulsifier formed of a copolymer material comprising at least first and second segments, said segments differing from one another in at least one of their chemical affinities, their compositions and their polarities, wherein a first one of said segments is soluble in an uncured liquid matrix polymer used in forming the film, but insoluble in a liquid suspension medium in which said droplets are dispersed, and a second one of said segments is soluble in the liquid suspending medium of the droplets and insoluble in the uncured liquid matrix polymer, wherein the first and second segments have substantially the same index of refraction in the range of 1.4630 to 1.4800 and wherein the index of refraction of said segments is within 0.010 of that of each phase of an emulsion formed with said emulsifier, said first segment comprised of a material selected from the group consisting of linear organosiloxanes, branched organosiloxanes, linear alkyl groups, branched alkyl groups, linear fluoroalkyl groups and branched fluoroalkyl groups and said second segment comprised of a material selected from the group consisting of linear esters, branched esters, linear (meth)acrylate, branched (meth)acrylate, linear amide, branched amide, linear amine, branched amine, linear epoxy groups, branched epoxy groups, linear groups comprising hydroxyl or acid groups and branched groups comprising hydroxyl or acid groups, wherein one segment of the emulsifier copolymer is comprised of a polyorganosiloxane polymer having pendant phenyl groups and the weight percent of the polyorganosiloxane in the emulsifier ranges from about 35% to about 65% by weight, wherein said emulsifier substantially prevents coalescence of the droplets of the liquid light valve suspension during formation of said film by retarding growth of said droplets.