Electrophoretic fluid
AssigneeMerck Patent GmbH
InventorNathan Smith
Life of this patent
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Abstract
This invention relates to electrophoretic fluids comprising a solvent, a dye, white particles, and colored particles selected from red, green, blue, magenta, cyan, yellow particles, and mixtures thereof, and electrophoretic display devices comprising such fluids.
Claims17
An electrophoretic fluid comprising at least one solvent, at least one dye, and a) white particles, and at least one set of colored particles or b) at least two sets of colored particles having different colors and optionally white particles, wherein the colored particles in a) and b) are selected from red, green, blue, magenta, cyan, and yellow particles, and mixtures thereof;
- wherein the electrophoretic fluid comprises at least one dye according to Formula I, Formula II, Formula III, Formula IV, Formula V or Formula VI
- wherein
- X and X′ are independently of one another H or an electron-withdrawing group;
- R1 and R2 are independently of one another groups are linear or branched, substituted or unsubstituted alkyl groups where one or more non-adjacent carbon atoms may be replaced by O, S and/or N;
- R3 and R4 are independently of one another groups are linear or branched, substituted or unsubstituted alkyl groups where one or more non-adjacent carbon atoms may be replaced by O, S and/or N;
- R5 is a methyl or methoxy group;
- and the dye comprises at least one electron-withdrawing group;
- wherein
- R6 and R7 are independently of one another groups are linear or branched, substituted or unsubstituted alkyl groups where one or more non-adjacent carbon atoms may be replaced by O, S and/or N;
- wherein
- X″ is an electron-withdrawing group;
- R8 is a methyl or methoxy group;
- R9 and R10 are independently of one another groups are linear or branched, substituted or unsubstituted alkyl groups where one or more non-adjacent carbon atoms may be replaced by O, S and/or N;
- wherein
- R12 and R13 are independently of one another groups are linear or branched, substituted or unsubstituted alkyl groups where one or more non-adjacent carbon atoms may be replaced by O, S and/or N;
- R11 is an alkyl or alkoxy group with at least 3 carbon atoms;
- wherein
- R14 and R15 are independently of one another groups are linear or branched, substituted or unsubstituted C8-C20 alkyl groups where one or more non-adjacent carbon atoms may be replaced by O, S and/or N;
- wherein
- X′″ is an electron-withdrawing group;
- R16 and R17 are independently of one another groups are linear or branched, substituted or unsubstituted alkyl groups where one or more non-adjacent carbon atoms may be replaced by O, S and/or N;
- R18 is NHCOR with R=linear or branched C1-C10 alkyl groups.
A method comprising displaying different color states in an electrophoretic display comprising an electrophoretic fluid comprising at least one solvent, at least one dye, and a) white particles, and at least one set of colored particles or b) at least two sets of colored particles having different colors and optionally white particles, wherein the colored particles in a) and b) are selected from red, green, blue, magenta, cyan, and yellow particles, and mixtures thereof by moving the particles vertically and increasing or reducing the spacing between white particles and/or colored particles;
- said method comprising:
- a) achieving a first color state based on to the color of a first set of particles by reducing the spacing between the particles of the first set of particles,
- b) achieving a second color state based on the color of a second set of particles by reducing the spacing between the colored particles of the second set of particles,
- c) achieving a third color state based on the color of the dye and on the color of the first set of coloured colored particles by increasing the spacing between the colored particles of the first set of particles,
- d) achieving a fourth color state based on the color of the dye and on the color of the second set of colored particles by increasing the spacing between the colored particles of the second set of particles, and optionally
- e) achieving a white color state by reducing the spacing between the white particles.
Dependencies are inferred from the claim text.