Electrophoretic compositions

1. 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.

2. The method of claim 1 wherein n is 1-4 or m is 0-5.

3. The method of claim 1 wherein R f , R f ′ and R f ″ are independently a fluorinated alkyl, fluorinated aryl, fluorinated-arylalkyl, aryl-fluorinated alkyl, fluorinated-alkylaryl, alkyl-fluorinated aryl or a fluorinated polymeric or oligomeric chain.

4. The method of claim 1 wherein X, X′ and X″ are independently alkylene, arylene, alkylene-oxy or alkylene-NR 1 — wherein R 1 is hydrogen or alkyl.

5. The method of claim 1 wherein the additive comprises at least 20% by weight of fluorine.

6. The method of claim 1 wherein R f , R f ′ or R f ″ is represented by Formula (R f ) below:

wherein the open un-designated substituent positions on the main chain are independently selected from the group consisting of hydrogen, halogen, alkyl, aryl, alkylaryl, arylalkyl, fluoroalkyl, fluoroaryl, fluoro-alkylaryl, alkylfluoro-aryl, fluoro-arylalkyl, arylfluoro-alkyl, —OR 4 , —OC(O)R 4 , —C(O)OR 4 , and —C(O)NR 4 R 5— , wherein R 4 and R 5 are independently hydrogen, alkyl, aryl, alkylaryl, arylalkyl, fluoroalkyl, fluoroaryl, fluoro-alkylaryl, alkylfluoro-aryl, fluoro-arylalkyl, arylfluoro-alkyl or a fluorinated polyether;

Z 1 , Z 2 , Z 3 and Z 4 are independently oxygen or absent; and

a, b, c and d are independently from 0 to 500 and the sum of a+b+c+d is from 3 to 1000.

7. The method of claim 6 wherein the open un-designated substituent positions are independently a fluorine or a fluorinated alkyl.

8. The method of claim 7 wherein the fluorinated alkyl is fluorinated methyl.

9. The method of claim 1 wherein X, X′ and X″ are independently absent or alkylene.

10. The method of claim 1 wherein the additive is Formula (A-1) wherein n is 1, X is absent, A is —COO— and B is hydrogen, or Formula (A-1) wherein n is 1, X is absent, A is —C(O)NR 2 — and —R 2 NC(O)— wherein R 2 is hydrogen or alkyl and B is a heteroarylalkyl, or a mixture thereof.

11. The method of claim 1 wherein the additive is Formula (A-1) wherein n is 2, X is absent or alkylene, A is —C(O)NR 2 — wherein R 2 is hydrogen or alkyl.

12. The method of claim 1 wherein the additive is Formula (A-1) wherein A is —R 2 NC(O)NR 3 — or —OC(O)NR 2 — in which R 2 and R 3 are independently hydrogen or alkyl.

13. The method of claim 1 wherein the additive is Formula (A-2) in which n is 2 or 3, B is N≡, an alkyl or a heteroalkyl, A and A′ are independently —C(O)NR 2 —, —R 2 NC(O)—, —R 2 NC(O)NR 3 —, —C(O)O—, —O(O)C—, —R 2 NC(O)O— or —OC(O)NR 2 —, X and X′ are independently absent or alkylene and B′ is an optionally substituted alkyl or optionally substituted aryl.

14. The method of claim 1 wherein the additive is Formula (B-1) in which m is 1 or 2, X, X′ and X″ are independently absent or alkylene, A, A′ and A″ are independently —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; and B, B′ and B″ are independently an optionally substituted alkyl or optionally substituted aryl.

15. An electrophoretic dispersion which comprises electrophoretic pigment-containing microparticles dispersed in a dielectric solvent or solvent mixture and 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, wherein the electrophoretic pigment-containing microparticles are prepared from microencapsulation having a continuous phase which comprises a protective colloid.

16. The electrophoretic dispersion of claim 15 wherein R f , R f ′ and R f ″ are independently a fluorinated alkyl, fluorinated aryl, fluorinated-arylalkyl, aryl-fluorinated alkyl, fluorinated-alkylaryl, alkyl-fluorinated aryl or a fluorinated polymeric or oligomeric chain.

17. The electrophoretic dispersion of claim 15 wherein X, X′ and X″ are independently alkylene, arylene, alkylene-oxy or alkylene-NR 1 — wherein R 1 is hydrogen or alkyl.

18. The electrophoretic dispersion of claim 15 wherein A is —C(O)NR 2 — in which R 2 is alkyl.

19. The electrophoretic dispersion of claim 15 wherein A is —R 2 NC(O)NR 3 — or —OC(O)NR 2 — in which R 2 and R 3 are independently hydrogen or alkyl.

20. An electrophoretic display comprising display cells filled with an electrophoretic dispersion which comprises:

a) electrophoretic pigment-containing microparticles;

b) a dielectric solvent or solvent mixture; and

c) one or more highly fluorinated additive 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. wherein the electrophoretic pigment-containing microparticles are prepared from microencapsulation having a continuous phase which comprises a protective colloid.

21. The electrophoretic display of claim 20 wherein R f , R f ′ and R f ″ are independently a fluorinated alkyl, fluorinated aryl, fluorinated-arylalkyl, aryl-fluorinated alkyl, fluorinated-alkylaryl, alkyl-fluorinated aryl or a fluorinated polymeric or oligomeric chain.

22. The electrophoretic display of claim 20 wherein X, X′ and X″ are independently alkylene, arylene, alkylene-oxy or alkylene-NR 1 — wherein R 1 is hydrogen or alkyl.

23. The electrophoretic display of claim 20 wherein A is —C(O)NR 2 — in which R 2 is alkyl.

24. The electrophoretic display of claim 20 wherein A is —R 2 NC(O)NR 3 — or —OC(O)NR 2 — in which R 2 and R 3 are independently hydrogen or alkyl.

25. The electrophoretic display of claim 20 which is prepared by the microcup technology.

26. The electrophoretic display of claim 20 which is prepared by a microencapsulation process.

27. The electrophoretic display of claim 20 which has a traditional up/down switching mode, or an in-plane switching mode or a dual switching mode.

28. The method of claim 5 wherein the additive comprises at least 30% by weight of fluorine.

29. The method of claim 28 wherein the additive comprises at least 50% by weight of fluorine.

30. The method of claim 6 wherein a and d are 0, Z 2 is oxygen and Z 3 is absent.

31. The method of claim 6 wherein a is 0, Z 2 and Z 3 are oxygen and Z 4 is absent.

32. The method of claim 8 wherein c and d are 0, Z 1 is oxygen and Z 2 is absent.

33. The method of claim 30 wherein Formula (R f ) is —(C 3 F 6 O) y CF(CF 3 )— wherein y is 1-500.

34. The method of claim 31 wherein Formula (R f ) is —CF 2 O(CF 2 CF 2 O) y (CF 2 O) z CF 2 — wherein y and z are independently 1-500.

35. The method of claim 32 wherein Formula (R f ) is —(C 3 F 6 O) y CF 2 CF 2 — wherein y is 1-500.

36. The method of claim 10 wherein R f is —(C 3 F 6 O) y CF(CF 3 )— wherein y is 1-500.

37. The method of claim 10 further comprising another additive which is Formula (A-1) wherein n is 2, X is methylene, A is —O— and B is hydrogen.

38. The method of claim 37 wherein R f is —CF 2 O(CF 2 CF 2 O) y (CF 2 O) z CF 2 — wherein y and z are independently 1-500.

39. The method of claim 11 wherein R 2 is alkyl.

40. The method of claim 11 wherein B is an optionally substituted alkyl.

41. The method of claim 11 wherein B is a cyclic alkyl of 3-8 carbon atoms.

42. The method of claim 39 wherein B with N and R 2 in —C(O)NR 2 — or R 2 NC(O)— forms a heterocyclic moiety having 4-8 members.

43. The method of claim 12 wherein one of R 2 and R 3 in —R 2 NC(O)NR 3 — is hydrogen and the other is alkyl or both are alkyl.

44. The method of claim 12 wherein R 2 in —R 2 NC(O)O— or OC(O)NR 2 — is alkyl.

45. The method of claim 12 wherein B is an optionally substituted alkyl or an optionally substituted aryl.

46. The electrophoretic dispersion of claim 19 wherein one of R 2 and R 3 in —R 2 NC(O)NR 3 — is hydrogen and the other is alkyl or both are alkyl.

47. The electrophoretic dispersion of claim 19 wherein R 2 in —R 2 NC(O)O— or —OC(O)NR 2 — is alkyl.

48. The electrophoretic dispersion of claim 15 wherein said electrophoretic pigment-containing microparticles are prepared by a process comprising an interfacial polymerization or crosslinking step, or by a process comprising an in-situ polymerization step, or by a process comprising a coacervation step.

49. The electrophoretic dispersion of claim 15 wherein said electrophoretic pigment-containing microparticles comprise a charge controlling agent.

50. The electrophoretic dispersion of claim 15 wherein said one or more additives are present in the amount of from about 0.5% to about 10% by weight based upon the total dry weight of the electrophoretic pigment-containing microparticles.

51. The electrophoretic display of claim 24 wherein one of R 2 and R 3 in —R 2 NC(O)NR 3 — is hydrogen and the other is alkyl or both are alkyl.

52. The electrophoretic display of claim 24 wherein R 2 in —R 2 NC(O)O— or —OC(O)NR 2 — is alkyl.

53. The method of claim 1 wherein said one or more additives are present in the amount of from about 0.5% to about 10% by weight based upon the total dry weight of the electrophoretic pigment-containing microparticles.

54. The electrophoretic display of claim 20 wherein said one or more additives are present in the amount of from about 0.5% to about 10% by weight based upon the total dry weight of the electrophoretic pigment-containing microparticles.

55. The method of claim 1 wherein said one or more additives are present in the amount of from about 0.1% to about 30% by weight based upon the total dry weight of the electrophoretic pigment-containing microparticles.

56. The electrophoretic dispersion of claim 15 wherein said one or more additives are present in the amount of from about 0.1% to about 30% by weight based upon the total dry weight of the electrophoretic pigment-containing microparticles.

57. The electrophoretic display of claim 20 wherein said one or more additives are present in the amount of from about 0.1% to about 30% by weight based upon the total dry weight of the electrophoretic pigment-containing microparticles.

58. The method of claim 1 wherein said protective colloid comprises a reactive functional group selected from the group consisting of amino, hydroxy, thiol, isocyanate, thioisocyanate, epoxide, aziridne, a short-chain alkoxysilyl, a carboxylic acid derivative, chioroformate and other functional groups capable of undergoing interfacial polymerization or crosslinking.

59. The electrophoretic dispersion of claim 15 wherein said protective colloid comprises a reactive functional group selected from the group consisting of amino, hydroxy, thiol, isocyanate, thioisocyanate, epoxide, aziridne, a short-chain alkoxysilyl, a carboxylic acid derivative, chloroformate and other functional groups capable of undergoing interfacial polymerization or crosslinking.

60. The electrophoretic display of claim 20 wherein said protective colloid comprises a reactive functional group selected from the group consisting of amino, hydroxy, thiol, isocyanate, thioisocyanate, epoxide, aziridne, a short-chain alkoxysilyl, a carboxylic acid derivative, chloroformate and other functional groups capable of undergoing interfacial polymerization or crosslinking.

61. The method of claim 1 wherein said electrophoretic pigment-containing microparticles are formed by emulsifying an internal phase comprising primary pigment particles and a polymer precursor into said continuous phase.

62. The electrophoretic dispersion of claim 15 wherein said electrophoretic pigment-containing microparticles are formed by emulsifying an internal phase comprising primary pigment particles and a polymer precursor into said continuous phase.

63. The electrophoretic display of claim 20 wherein said electrophoretic pigment-containing microparticles are formed by emulsifying an internal phase comprising primary pigment particles and a polymer precursor into said continuous phase.