IP Library › Granted Patent US 7,504,188
Granted Patent B2
US 7,504,188 · App. 11/938,335 · Granted Mar 17, 2009

Toner and developer, toner container, process cartridge, image forming apparatus, and image forming method using the same

Assignee: Ricoh Company, Ltd.
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Quick Facts
Patent No.
US 7,504,188
App. No.
11/938,335
Granted
Mar 17, 2009
Kind
B2
Abstract

To provide a toner containing an ethyl acetate-soluble polyester component and an ethyl acetate-insoluble polyester component, wherein the toner is granulated in an aqueous medium, the ethyl acetate-insoluble polyester component is obtained by elongating and/or cross-linking a modified polyester resin during granulating and/or after granulating, the modified polyester resin is produced by condensation polymerization of an acid component and at least one type of diol compound selected from aliphatic diol and alicyclic diol in the presence of a catalyst, and the mass average molecular weight of the modified polyester resin is 10,000 to 100,000.

Claims (16)

1. A toner comprising:

a binder resin, and

a colorant,

wherein the binder resin comprises secondary modified polyester which can be obtained by cross-linking a primary modified polyester (B) derived from polyester as a precursor (A), wherein

the mass average molecular weight of the precursor (A) is 10,000 to 90,000, and the glass transition temperature (Tg) of the toner is in the range of 40° C. to 55° C.

2. The toner according to claim 1 , wherein the precursor (A) is modified such that functional groups capable of reacting with active hydrogen groups are introduced in the primary modified polyester (B).

3. The toner according to claim 2 , wherein the functional groups contained in the primary modified polyester (B) are isocyanate groups.

4. The toner according to claim 1 , wherein the secondary modified polyester is obtained by reacting the primary modified polyester (B) with an active hydrogen group-containing compound (C).

5. The toner according to claim 1 , wherein the toner is granulated in an aqueous medium.

6. The toner according to claim 1 , wherein the toner is produced by dispersing an oil layer containing an organic solvent in an aqueous medium to obtain an emulsified dispersion liquid, elongating and/or cross-linking the primary modified polyester (B) with an active hydrogen group-containing compound (C) in the emulsified dispersion liquid to form toner particles and removing the organic solvent in the emulsified dispersion liquid, wherein the oil layer is obtained by dissolving or dispersing a toner composition comprising the primary modified polyester (B) and the active hydrogen group-containing compound (C) in the organic solvent, and the primary modified polyester (B) comprises functional groups capable of reacting with an active hydrogen group.

7. The toner according to claim 1 , wherein the glass transition temperature (Tg) of the precursor (A) is 30° C. to 50° C.

8. The toner according to claim 1 , wherein the volume average particle diameter (Dv) of the toner is 3 μm to 8 μm.

9. The toner according to claim 1 , wherein a ratio of the volume average particle diameter (Dv) to the number average particle diameter (Dn), Dv/Dn is 1.25 or less.

10. The toner according to claim 1 , wherein the glass transition temperature (Tg) of the precursor (A) is 30° C. to 40° C.

11. The toner according to claim 1 , wherein the mass average molecular weight of the precursor (A) is 10,000 to 50,000.

12. The toner according to claim 1 , wherein the average molecular weight of the primary modified polyester (B) is 10,000 to 100,000.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 2, 2008
From: YAMADA, MASAHIDE; INOUE, RYOTA; WATANABE, NAOHIRO; EMOTO, SHIGERU; OHKI, MASAHIRO; SAITOH, AKINORI; SUGIYAMA, TSUNEMI; WAKAMATSU, SHINICHI; NANYA, TOSHIKI; SHIMOTA, NAOHITO; YAMADA, HIROSHI; AWAMURA, JUNICHI; SUZUKI, TOMOMI; HIRAI, KAZUYUKI; YASUMATSU, KAZUSHIGE
To: RICOH COMPANY, LTD.
Reel/Frame 020307/0250 →
Priority Claims (2)
JP 2005-137291 · May 10, 2005 · national
JP 2005-144453 · May 17, 2005 · national
Continuity (2)
Continuation PCTJP200630976600 · May 10, 2006
Related Publication 20080090165A1 · Apr 17, 2008