Extended temperature range polymer dispersed liquid crystal light shutters
First Claim
1. A liquid crystal light modulating material comprising a liquid crystal phase in a cross-linked polymeric matrix, the liquid crystal phase being effective to scatter incident light in the absence of an applied field, the liquid crystal phase further being responsive to an applied field to transmit incident light from about -40°
- C. to 80°
, and the matrix being effective to maintain the liquid crystal phase in a scattering condition in the absence of an applied field.
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Accused Products
Abstract
An extended temperature range polymer dispersed liquid crystal light shutter electrically switchable between a transmissive and an opaque state over a working temperature range of about -40° C. to about 100° C. The shutter includes a polymer-dispersed liquid crystalline (PDLC) material comprising a fairly highly cross-linked transparent matrix having phase-separated microdroplets of liquid crystal dispersed therein, the liquid crystal existing in a supercooled liquid crystalline state at low temperatures. Such light shutters are employed in various windows and electrooptic displays, wherever it is desirable to be able to adjust visible or transparency and regardless of temperature extremes.
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Citations
22 Claims
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1. A liquid crystal light modulating material comprising a liquid crystal phase in a cross-linked polymeric matrix, the liquid crystal phase being effective to scatter incident light in the absence of an applied field, the liquid crystal phase further being responsive to an applied field to transmit incident light from about -40°
- C. to 80°
, and the matrix being effective to maintain the liquid crystal phase in a scattering condition in the absence of an applied field. - View Dependent Claims (2, 3, 4)
- C. to 80°
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5. An extended temperature range polymer dispersed liquid crystal light shutter electrically switchable between a transmissive and an opaque state over a working temperature range of about -40°
- C. to about 100°
C., said shutter including a polymer-dispersed liquid crystalline material comprising a highly cross-linked transparent matrix having phase-separated microdroplets of liquid crystal dispersed therein, the liquid crystal capable of existing in a supercooled liquid crystalline state at temperatures below its freezing point. - View Dependent Claims (6, 7)
- C. to about 100°
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8. An extended temperature range polymer dispersed liquid crystal light shutter electrically switchable between a transmissive and an opaque state over a working temperature range of about -40°
- C. to about 100°
C., said shutter including a polymer-dispersed liquid crystalline material comprising a highly cross-linked transparent matrix having phase-separated microdroplets of liquid crystal dispersed therein, the liquid crystal capable of existing in a liquid crystalline state at temperatures above the liquid crystalline to liquid phase transition temperature of the bulk liquid crystal. - View Dependent Claims (9, 10)
- C. to about 100°
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11. A method of making an extended temperature range light modulating material comprising the step of curing a solution of liquid crystal in matrix providing material with a curing agent effective to tightly bind the matrix so that the resultant liquid crystal microdroplets spontaneously formed upon curing are capable of responding to an applied field to transmit incident light, and the matrix is capable of maintaining the microdroplets in a scattering condition in the absence of an applied field and the matrix further capable of maintaining the microdroplets responsive to an applied field to transmit incident light from about -40°
- C. to 80°
C. - View Dependent Claims (12)
- C. to 80°
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13. A method of making an extended temperature range light modulating material of microdroplets of liquid crystal phase-separated in a light transmissive matrix and electrically switchable between a transmissive and an opaque state over a working temperature range of about -40°
- C. to about 100°
C., comprising the step of curing a matrix-providing composition to provide an effective degree of cross-linking so that the phase-separated microdroplets of liquid crystal dispersed therein are maintained in a supercooled liquid crystalline state at temperatures below the liquid crystal freezing point.
- C. to about 100°
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14. A method of making an extended temperature range light modulating material of microdroplets of liquid crystal phase-separated in a light transmissive matrix and electrically switchable between a transmissive and an opaque state over a working temperature range of about -40°
- C. to about 100°
C., comprising the step of curing a matrix-providing composition to provide an effective degree of cross-linking so that the phase-separated microdroplets of liquid crystal dispersed therein are capable of existing in a liquid crystalline state at temperatures above the liquid crystalline to liquid phase transition temperature of the bulk liquid crystal.
- C. to about 100°
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15. An extended temperature range light modulating material comprising a liquid crystal phase in a transparent polymer matrix;
said matrix being cross-linked to a degree effective to maintain the microdroplets in a condition to transmit light in the presence of an applied field and to scatter light in the absence of an applied field over a working temperature range of -40°
C. to 80°
C.- View Dependent Claims (16, 17, 18)
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19. An extended temperature range light modulating material comprising microdroplets of liquid crystal in a transparent polymeric matrix;
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said light modulating material being switchable between transmissive and opaque states over a working temperature range of about -40°
C. to 80°
C.; andsaid matrix being cross-linked to a degree effective to maintain the microdroplets in a liquid crystalline state at a temperature above to liquid-crystalline-to-isotropic-liquid phase transition temperature of the liquid crystal in bulk. - View Dependent Claims (20, 21, 22)
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Specification