Light valve for controlling the transmission of radiation comprising a cell and a stabilized liquid suspension
First Claim
1. A light valve for controlling the transmission of radiation, which comprises a cell and a liquid suspension in said cell;
- said liquid suspension comprising;
an electrically resistive liquid suspending medium;
a plurality of small, anisometrically shaped, light-polarizing, halogen-containing particles suspended in said suspending medium; and
a copolymer of at least two different monomers;
at least one of said monomers having a sterically unhindered functional group selected from the group consisting of an OH group and an acidic group, and at least one of said monomers having a branched group, the distance from the backbone of the copolymer to said sterically unhindered functional group most distant from the backbone being less than the distance from the backbone to the terminal group of said branched group, the branched groups in said copolymer being sufficiently soluble so that the copolymer as a whole is substantially dissolved in said liquid suspending medium.
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Accused Products
Abstract
Polymeric materials which are used to stabilize particles including colloidal size particles, particularly particles which polarize light or other radiation and include halogen in their composition. The materials are long chain molecular copolymers having available functional groups such as OH or acidic groups in their structure and are soluble in liquids in which the colloidal particles are suspendable. At least one monomer of those used to form the copolymer has a branched structure, which may include more than one branch. Some of the materials are copolymers of 3,5,5-trimethylhexyl acrylate/2-hydroxypropyl acrylate/fumaric acid; 5,5-diethyl hexyl acrylate/2-hydrooxypropyl acrylate/fumaric acid; and bis-2-ethylhexyl fumarate/3,5,5-trimethyl hexyl acrylate/vinylidene chloride/mesaconic acid. The materials retard or prevent the suspended particles in light valve suspensions from grouping together when a voltage is placed across the suspension containing these particles. The materials also reduce the voltage and electrical power needed to achieve a given change in light transmission for a light valve. They also enable suspensions to be used at elevated temperatures without significant degradation.
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Citations
25 Claims
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1. A light valve for controlling the transmission of radiation, which comprises a cell and a liquid suspension in said cell;
- said liquid suspension comprising;
an electrically resistive liquid suspending medium; a plurality of small, anisometrically shaped, light-polarizing, halogen-containing particles suspended in said suspending medium; and a copolymer of at least two different monomers; at least one of said monomers having a sterically unhindered functional group selected from the group consisting of an OH group and an acidic group, and at least one of said monomers having a branched group, the distance from the backbone of the copolymer to said sterically unhindered functional group most distant from the backbone being less than the distance from the backbone to the terminal group of said branched group, the branched groups in said copolymer being sufficiently soluble so that the copolymer as a whole is substantially dissolved in said liquid suspending medium. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
- said liquid suspension comprising;
Specification