Patent ID: 7277218

Claim:
A method for improving threshold characteristics and temperature latitude of an electrophoretic display, which method comprises a) preparing an electrophoretic dispersion comprising electrophoretic pigment-containing microparticles dispersed in a dielectric solvent or solvent mixture wherein said electrophoretic pigment-containing microparticles are prepared from microencapsulation having a continuous phase which comprises a protective colloid; and b) adding into said electrophoretic dispersion one or more fluorinated additives represented by the following formulas (A-1), (A-2), (B-1), (B-2) and (B-3): R f —(—X-A-B) n (A-1) B-(-A-X—R f —X′-A′-B) n (A-2) B″-A″-X″—(—R f —X-A-B-A-X—) m —R f ′—X′-A′-B′ (B-1) R f ″—X″-A″-B″-A″-X″—(—R f —X-A-B-A-X—) m —R f ′ (B-2) R f ″—X″-A″-B″-A″-X—(—R f —X-A-B-A-X—) m —R f ′—X′-A′-B′ (B-3) wherein: n is an integer which is ≧1; m is 0 or an integer which is ≧1; R f , R f ′ and R f ″ are independently a fluorinated moiety; X, X′ and X″ are independently absent or a linking group; A, A′ and A″ are independently —O—, —C(O)O—, —O(O)C—, —C(O)NR 2 —, —R 2 NC(O)—, —R 2 NC(O)NR 3 —, —R 2 NC(O)O— or —OC(O)NR 2 —, wherein R 2 and R 3 are independently hydrogen or alkyl; B, B′ and B″ are independently hydrogen, N≡, optionally substituted alkyl, optionally substituted aryl, optionally substituted heteroalkyl or optionally substituted heteroaryl; or N and R 2 in —C(O)NR 2 —or —R 2 NC(O)— of A form a cyclic moiety with B; or N and R 3 in —R 2 NC(O)NR 3 — of A form a cyclic moiety with B; or N and R 2 in —R 2 NC(O)O— or —OC(O)NR 2 — of A form a cyclic moiety with B.