Planar fluorinated dielectric suspensions for electrophoretic image displays and related methods

Claim 2

A electrophoretic dielectric suspension that is environmentally acceptable and chlorine-free comprising: a suspension medium including at least one chlorine-free fluorinated solvent and at least one hydrocarbon solvent, said at least one chlorine-free fluorinated solvent comprising approximately 54.42 to 75.20 weight percent of said electrophoretic dielectric suspension and said at least one hydrocarbon solvent comprising approximately 22.50 to 44.25 weight percent of said electrophoretic dielectric suspension; a plurality of pigment particles dispersed in said suspension medium, said plurality of pigment particles comprising approximately 0.70 to 1.20 weight percent of said suspension medium; a fluid dye dissolved in said suspension medium for providing a contrast with said pigment particles, said fluid dye comprising approximately 0.008 to 0.50 weight percent of said suspension medium; and a fluorosurfactant absorbed on said pigment particles for preventing said pigment particles from agglomerating, said fluorosurfactant comprising approximately 0.10 to 1.50 weight percent of said suspension medium.

Claim 3

The electrophoretic dielectric suspension according to claim 1, wherein said at least one chlorine-free fluorinated solvent is a dense fluorinated solvent.

Claim 4

The electrophoretic dielectric suspension according to claim 1, wherein said at least one hydrocarbon solvent is less dense than said at least one chlorine-free fluorinated solvent.

Claim 5

The electrophoretic dielectric suspension according to claim 1, wherein said at least one chlorine-free fluorinated solvent is selected from a group consisting of perfluorotoluene, perfluorocyclohexane, perfluorodimethylcyclohexane, perfluoromethylcyclohexane, perfluoroxylene, perfluorobenzene, perfluorodecalin, perfluorodecane, perfluorohexane, perfluorooctane, perfluorodecane, trifluorotoluene, pentafluorotoluene and low molecular weight liquid polymers having the structure of fluorinated polyethers.

Claim 6

The electrophoretic dielectric suspension according to claim 1, wherein said hydrocarbon solvent is from a group consisting of a mixture of phenylxylylethanes, toluene, benzene, xylene, cyclohexane, sec-butylbenzene, phenyloctane decane, octane, hexadecane and decahydronaphthalene.

Claim 7

The electrophoretic dielectric suspension according to claim 1, wherein said at least one chlorine-free fluorinated solvent comprises two different chlorine-free fluorinated solvents.

Claim 8

The electrophoretic dielectric suspension according to claim 1, wherein said at least one hydrocarbon solvent comprises two different hydrocarbon solvents.

Claim 9

The electrophoretic dielectric suspension according to claim 1, wherein said fluorosurfactant has the formula ##STR1## where [R1] is a fluorocarbon and N is the number of repeat units between 3 and 20, and where is an ethoxy hydrocarbon and M is the number or repeat units between 3 and 20.

Claim 10

The electrophoretic dielectric suspension according to claim 1, wherein said fluorosurfactant is polymeric containing a block which is primarily carbon and hydrogen and a block which is primarily carbon and fluorine.

Claim 11

A process for making a electrophoretic dielectric suspension for an electrophoretic display that is environmentally acceptable and chlorine-free, comprising the steps of: combining at least one chlorine-free fluorinated solvent with at least one hydrocarbon solvent to form a suspension medium, said at least one chlorine-free fluorinated solvent comprising approximately 54.42 to 75.20 weight percent of said dielectric suspension and said at least one hydrocarbon solvent comprising approximately 22.50 to 44.25 weight percent of said dielectric suspension; adding a plurality of pigment particles of a first color to said suspension medium, said plurality of pigment particles comprising approximately 0.70 to 1.20 weight percent of said suspension medium; adding a fluorosurfactant to said suspension medium to prevent agglomeration of said plurality of pigment particles, said fluorosurfactant comprising approximately 0.10 to 1.50 weight percent of said suspension medium; dissolving a fluid dye of a second color in said suspension medium, said fluid dye comprising approximately 0.008 to 0.50 weight percent of said suspension medium; and mixing said suspension medium to thoroughly disperse said pigment particles therein.

Claim 12

A process for making a electrophoretic dielectric suspension for an electrophoretic display that is environmentally acceptable and chlorine-free, comprising the steps of: combining at least one chlorine-free fluorinated solvent with at least one hydrocarbon solvent to form a suspension medium, said at least one chlorine-free fluorinated solvent comprising approximately 54.42 to 75.20 weight percent of said dielectric suspension and said at least one hydrocarbon solvent comprising approximately 22.50 to 44.25 weight percent of said dielectric suspension; adding a plurality of pigment particles of a first color to said suspension medium, said plurality of pigment particles comprising approximately 0.70 to 1.20 weight percent of said suspension medium; adding a fluorosurfactant to said suspension medium to prevent agglomeration of said plurality of pigment particles, said fluorosurfactant comprising approximately 0.10 to 1.50 weight percent of said suspension medium; dissolving a fluid dye of a second color in said suspension medium, said fluid dye comprising approximately 0.008 to 0.50 weight percent of said suspension medium; and mixing said suspension medium to thoroughly disperse said pigment particles therein.

Claim 13

The process according to claim 10, wherein said mixing step comprises ball milling.

Claim 14

The process according to claim 10, said mixing step comprises sonifying in an ultrasonic bath.

Claim 15

The process according to claim 10, wherein said at least one chlorine-free fluorinated solvent is a dense fluorinated solvent.

Claim 16

The process according to claim 10, wherein said at least one hydrocarbon solvent is less dense than said at least one chlorine-free fluorinated solvent.

Claim 17

The process according to claim 10, wherein said at least one chlorine-free fluorinated solvent is selected from a group consisting of perfluorotoluene, perfluorocyclohexane, perfluorodimethylcyclohexane, perfluoro-methylcyclohexane, perfluoroxylene, perfluorobenzene, perfluorodecalin, perfluorodecane, perfluorohexane, perfluoroctane, perfluorodecane, trifluorotoluene, pentafluorotoluene and low molecular weight liquid polymers having the structure of fluorinated polyethers.

Claim 18

The process according to claim 10, wherein said at least one hydrocarbon solvent is from a group consisting of a mixture of phenylxylylethanes, toluene, benzene, xylene, cyclohexane, sec-butylbenzene, phenyloctane, decane, octane, hexadecane, and decahydronaphthalene.

Claim 19

The process according to claim 10, wherein said fluorosurfactant has the formula ##STR2## where [R1] is a fluorocarbon and N is the number of repeat units between 3 and 20, and where is an ethoxy hydrocarbon and M is the number or repeat units between 3 and 20.

Claim 20

The process according to claim 10 wherein, said fluorosurfactant is polymeric including a block which is primarily carbon and hydrogen and a block which is primarily carbon and fluorine.

Claim 21

The process according to claim 10, further comprising the step of centrifuging said suspension to remove unwanted particulate matter.

Claim 22

The process according to claim 19, wherein said centrifuging of said suspension at 5000 rpm for between 1 and 2 hours.

Claim 23

The process according to claim 10, wherein said at least one chlorine-free fluorinated solvent comprises two different chlorine-free fluorinated solvents.

Claim 24

The process according to claim 10, wherein said at least one hydrocarbon solvent comprises two different hydrocarbon solvents.

Claim 25

The electrophoretic dielectric suspension according to claim 1, wherein said at least , one chlorine-free fluorinated solvent comprises approximately 54.42 weight percent of said electrophoretic dielectric suspension, said at least one hydrocarbon solvent comprising approximately 44.25 weight percent of said electrophoretic dielectric suspension, said plurality of pigment particles comprising approximately 0.74 weight percent of said suspension medium, said fluid dye comprising approximately 0.37 weight percent of said suspension medium, and said fluorosurfactant comprising approximately 0.22 weight percent of said suspension medium.

Claim 26

The electrophoretic dielectric suspension according to claim 1, wherein said at least one chlorine-free fluorinated solvent comprises approximately 75.20 weight percent of said electrophoretic dielectric suspension, said at least one hydrocarbon solvent comprising approximately 22.50 weight percent of said electrophoretic dielectric suspension, said plurality of pigment particles comprising approximately 1.00 weight percent of said suspension medium, said fluid dye comprising approximately 0.10 weight percent of said suspension medium, and said fluorosurfactant comprising approximately 1.20 weight percent of said suspension medium.

Claim 27

The process for making a electrophoretic dielectric suspension according to claim 10, wherein said at least one chlorine-free fluorinated solvent comprises approximately 54.42 weight percent of said electrophoretic dielectric suspension, said at least one hydrocarbon solvent comprising approximately 44.25 weight percent of said electrophoretic dielectric suspension, said plurality of pigment particles comprising approximately 0.74 weight percent of said suspension medium, said fluid dye comprising approximately 0.37 weight percent of said suspension medium, and said fluorosurfactant comprising approximately 0.22 weight percent of said suspension medium.

Claim 28

The process for making a electrophoretic dielectric suspension according to claim 10, wherein said at least one chlorine-free fluorinated solvent comprises approximately 75.20 weight percent of said electrophoretic dielectric suspension, said at least one hydrocarbon solvent comprising approximately 22.50 weight percent of said electrophoretic dielectric suspension, said plurality of pigment particles comprising approximately 1.00 weight percent of said suspension medium, said fluid dye comprising approximately 0.10 weight percent of said suspension medium, and said fluorosurfactant comprising approximately 1.20 weight percent of said suspension medium.