IP Library Granted Patent US 7,522,333
Granted Patent B2
US 7,522,333 · App. 11/379,188 · Granted Apr 21, 2009

Method of producing an electrophoretic particle, electrophoretic device, and electric apparatus

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Quick Facts
Patent No.
US 7,522,333
App. No.
11/379,188
Granted
Apr 21, 2009
Kind
B2
Abstract

A method for producing electrophoretic particles includes dispersing particles having a charge on the surfaces thereof in an polar dispersion medium; adding a first polymerizable surfactant including a first polar group having a polarity opposite to the charge of the surfaces of the particles, a hydrophobic group, and a polymerizable group to the polar dispersion medium and mixing the liquid; adding a second polymerizable surfactant including a second polar group, a hydrophobic group, and a polymerizable group to the polar dispersion medium and emulsifying the mixture; and adding a polymerization initiator to induce polymerization reaction, thereby preparing electrophoretic particles in which the particles are coated with an organic polymer. In the method, the charge polarity and the amount of charge of the electrophoretic particles are controlled by setting the polarity of the second polar group included in the second polymerizable surfactant, and at least one condition of the number of the second polar groups in second polymerizable surfactant, the valence of the second polymerizable surfactant, and the molar amount of the second polymerizable surfactant added.

Claims (33)

1. An electrophoretic particle, comprising:

a base particle; and

an organic polymer film;

the organic polymer film including a plurality of first polar groups, a plurality of second polar groups, and a polymerized film,

the plurality of the first polar groups being disposed between the base particle and the polymerized film,

the polymerized film being disposed between the plurality of first polar groups and the plurality of second polar groups.

2. The electrophoretic particle according to claim 1 , further comprising:

a silicon oxide layer disposed between the base particle and the organic polymer film.

3. The electrophoretic particle according to claim 1 ,

the organic polymer film further including a plurality of first hydrophobic groups, and the polymerized film being connected to the plurality of first polar groups through the plurality of first hydrophobic groups.

4. The electrophoretic particle according to claim 1 ,

the organic polymer film further including a plurality of second hydrophobic groups, and the polymerized film being connected to the plurality of second polar groups through the plurality of second hydrophobic groups.

5. The electrophoretic particle according to claim 1 , each of the plurality of first polar groups having a negative charge, and each of the plurality of second polar groups having a negative charge.

6. The electrophoretic particle according to claim 1 , each of the plurality of first polar groups having a negative charge, and each of the plurality of second polar groups having a positive charge.

7. The electrophoretic particle according to claim 1 , each of the plurality of first polar groups having a negative charge, and a positive charge against the negative charge being produced by a proton.

8. The electrophoretic particle according to claim 2 ,

each of the plurality of first polar groups having a negative charge, and

a positive charge against the negative charge being produced by a proton located between the silicon oxide layer and the polymerized film.

9. An electrophoretic device comprising:

a plurality of microcapsules, each of the microcapsules including the electrophoretic particle according to claim 1 ; and

a substrate on which the plurality of microcapsules is disposed.

10. An electric apparatus comprising:

the electrophoretic device according to claim 9 ; and

a main body section on which the electrophoretic device is disposed.

11. An electrophoretic particle, comprising:

a base particle; and

an organic polymer film;

the organic polymer film including a plurality of first polar groups, a plurality of hydrophobic groups, and a polymerized film,

the plurality of first polar groups being disposed between the base particle and the polymerized film, and

the polymerized film being disposed between the plurality of first polar groups and the plurality of hydrophobic groups.

12. The electrophoretic particle according to claim 11 , each of the plurality of first polar groups having a negative charge.

13. The electrophoretic particle according to claim 11 , each of the plurality of first polar groups having a negative charge, and a positive charge against the negative charge being produced by a proton.

14. The electrophoretic particle according to claim 11 , further comprising: a silicon oxide layer disposed between the base particle and the organic polymer film, and a positive charge against the negative charge being produced by proton located between the silicon oxide layer and the polymerized film.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 13, 2018
From: SEIKO EPSON CORPORATION
To: E INK CORPORATION
Reel/Frame 047072/0325 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 18, 2006
From: YAMAMOTO, HITOSHI; KAWASE, TAKEO; MIYABAYASHI, TOSHIYUKI
To: SEIKO EPSON CORPORATION
Reel/Frame 017499/0685 →