Abstract: Light-polarizing materials, and uses thereof in liquid suspensions, set suspensions and light valves.

Abstract: Light-polarizing materials comprising a complex obtained by reacting elemental iodine, and iodide and a monoalkyl- or dialkyl-piperazinedione or an unsubstituted or monoalkyl- or dialkyl- substituted 2,5-dicarboxy-pyrazine, and uses thereof in liquid suspensions, set suspensions and light valves.

Abstract: Light-polarizing materials, and uses thereof in liquid suspensions, set suspensions and light valves.

Abstract: In a light valve, comprising a cell containing a suspension of small anisometrically shaped particles suspended in an electrically resistive liquid suspending medium, said liquid suspending medium having a polymer dissolved therein and bonded to or associated with said particles, the improvement wherein said liquid suspending material comprises a liquid ester or ether of the formulaR.sup.1 --X--R.sup.2wherein R.sup.1 and R.sup.

Abstract: A light-polarizing perhalide of an alkaloid acid salt having incorporated in its molecular structure a chloride, bromide, or iodide of calcium, rubidium, cesium or bismuth, and a light valve containing a suspension of particles of such perhalide.

Abstract: In a light valve, comprising a cell containing a suspension of particles in a liquid suspending medium, the improvement wherein said light valve suspension comprises particles of a perhalide of an alkaloid acid salt or a light-polarizing metal halide or perhalide suspended in said liquid suspending medium and a protective polymer effective to inhibit agglomeration of said particles dissolved in said liquid suspending medium, said liquid suspending medium comprising an electrically resistive, inert, low molecular weight, liquid fluorocarbon polymer having a specific gravity at room temperature of at least about 1.5 and having at least about 50% of its atoms constituted by halogen atoms, at least 60% of said halogen atoms being fluorine and the balance chlorine and/or bromine, and an electrically resistive organic liquid miscible with the fluorocarbon liquid, said fluid suspending medium being operable to suspend said particles in substantial gravitational equilibrium.

Abstract: 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 particles suspended in said suspending medium;a copolymer of at least two different monomers, at least one of said monomers having a sterically unhindered functional group for bonding to or associating with said particles, 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; anda polymer dissolved in said liquid suspending medium and bonded to or associated with said copolymer but not

Abstract: A light valve comprises a cell containing a suspension of light-polarizing particles in a liquid suspending medium, the light polarizing particles being particles of a light-polarizing perhalide of a polycarboxylic acid salt of an alkaloid.

Abstract: In a light valve comprising a liquid suspension of small particles selected from the group consisting of halogenated alkaloid acid salts and metal halides in a liquid suspending medium, the improvement in which said liquid suspending medium comprises a liquid, saturated, aliphatic halogenated hydrocarbon having a ratio of halogen atoms to all other atoms therein of greater than 1:1, the halogen atoms of said particles being iodine and/or bromine and the halogen atoms of said halogenated hydrocarbon being of lower atomic weight than the halogen atoms of said particles, and at least 50% the halogen atoms of said halogenated hydrocarbon being selected from the group consisting of fluorine and chlorine.

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.

Abstract: An aliphatically unsaturated organic compound is hydrogenated to form a saturated compound and a salt of the saturated compound is reacted with a halogen and a halide to form a light-polarizing material. The light-polarizing material in the form of crystalline particles is dispersed in a suitable suspending medium to produce a fluid suspension thereof. The suspension is useful in light valves.

Abstract: A light valve including suspending materials which have an ability to prevent or substantially retard agglomeration of the particles in suspension during the application of a voltage to the suspension. The materials include aromatic esters which are derivable from aromatic alcohols, such as phenyl acetate, cresyl acetate, para-butylphenyl acetate, para-nonylphenyl acetate, and structurally similar compounds. The suspension also includes, as an additional suspending material, a polymer such as a branched polymeric coating material to coat the particles in suspension and act in combination with the aromatic ester suspending materials to prevent or substantially reduce agglomeration of the particles when a voltage is applied to the suspension. Other suspending materials such as non-aqueous liquids or solids may also form part of the suspending medium of this invention.

Abstract: A light valve and fluid suspension therefor which when activated decrease the transmission of radiation therethrough.

Abstract: A light valve including suspending materials which have an ability to prevent or substantially retard agglomeration of the particles in suspension during the application of a voltage to the suspension. The materials comprise aromatic esters which are derivable from aromatic alcohols, such as phenyl acetate, cresyl acetate and structurally similar compounds. Other suspending material such as non-aqueous liquids or solids may also form part of the suspending medium of this invention, used to suspend the particles. The suspension also may include a coating material to coat the particles in suspension and act in combination with the suspending materials to prevent or substantially reduce agglomeration of the particles when a voltage is applied to the suspension.