Electrophoretic fluid

An electrophoretic fluid comprising at least one solvent, at least two kinds of particles having different colour and opposite electrical charge, and at least one highly absorbing dye, wherein the dye or a dye mixture has an absorbance of at least 0.3 a.u. in a cell thickness of 50 microns, and wherein the electrophoretic fluid comprise 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 group 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.