IP Library › Granted Patent US 7,670,741
Granted Patent B2
US 7,670,741 · App. 11/687,075 · Granted Mar 2, 2010

Toner

Assignee: Ricoh Company, Ltd.
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Quick Facts
Patent No.
US 7,670,741
App. No.
11/687,075
Granted
Mar 2, 2010
Kind
B2
Abstract

A toner containing a toner particle manufactured by dispersing an organic solvent in which a component comprising a polymer having a portion reactive with an active hydrogen group is dispersed or dissolved in an aqueous medium; and reacting the polymer with a compound having at least one active hydrogen group, where the polymer is prepared by reacting an aliphatic polyol, a polyester resin and a diisocyanate compound and has an isocyanate group on at least one end of the polymer.

Claims (14)

1. A toner comprising a toner particle manufactured by a method, comprising:

dispersing an organic solvent in which a component comprising a polymer having a portion that is reactive with active hydrogen of an active hydrogen containing group is dispersed or dissolved in an aqueous medium; and

reacting the polymer with a compound having at least one active hydrogen-containing group,

wherein the polymer is prepared by reacting an aliphatic polyol, a polyester resin and a diisocyanate compound and has an isocyanate group on at least one end of the polymer.

2. The toner according to claim 1 , wherein the number of carbon atoms in a main chain of the aliphatic polyol is 3 to 10.

3. The toner according to claim 1 , wherein the hydroxyl group value of a mixture of the aliphatic polyol and the polyester resin is 15 to 30 mgKOH/g.

4. The toner according to claim 1 , wherein the hydroxyl group value of the polyester resin is 14 to 26 mgKOH/g.

5. The toner according to claim 1 , wherein said particle has a glass transition temperature of 40 to 70° C.

6. The toner according to claim 1 , wherein said particle has a weight average particle diameter of 3 to 8 μm.

7. The toner according to claim 1 , wherein said particle has a ratio of a weight average particle diameter to a number average particle diameter of 1.00 to 1.25.

8. The toner according to claim 1 , wherein said particle has an average circularity of 0.90 to 1.00.

9. The toner according to claim 1 , wherein said particle has an acid value of 1 to 30 mgKOH/g.

10. The toner according to claim 1 , wherein the alcohol and the carboxylic acid are mixed in amounts so as to have an equivalence ratio ([OH])/[COOH]) ranging from 1 to 2.

11. The toner according to claim 1 , wherein, in the synthesis of a prepolymer having an isocyanate group at its terminus, the equivalence ratio of isocyanate group to hydroxyl group [OH] in the prepolymer ranges from 2 to 4.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 29, 2007
From: YAMADA, MASAHIDE; SAITOH, AKINORI; OHKI, MASAHIRO
To: RICOH COMPANY, LTD.
Reel/Frame 019350/0688 →
Priority Claims (1)
JP 2006-075645 · Mar 17, 2006 · national
Continuity (1)
Related Publication 20070218391A1 · Sep 20, 2007