Toner for electrostatic charge image development and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-9354535-B2
Application number	US-201514616212-A
Country	US
Kind code	B2
Filing date	Feb 6, 2015
Priority date	Feb 17, 2014
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

To provide a toner for electrostatic charge image development which allows obtainment of excellent low temperature fixability and a document off-set resistance sufficiently and also inhibition of an excessive increase in glossiness of a formed fixed image, and a method for manufacturing the same.
The toner for electrostatic charge image development includes toner particles containing a binder resin, a colorant, and a releasing agent, in which the binder resin contains at least an amorphous resin and an urethane modified crystalline resin including a crystalline polymer segment and an urethane polymer segment bound to each other, the urethane modified crystalline resin being non-compatible with the amorphous resin, and the amount of ionic dissociating group of the urethane modified crystalline resin is 5 to 20 mgKOH/g.

First claim

What is claimed is:

1. A toner for electrostatic charge image development comprising toner particles comprising a binder resin, a colorant, and a releasing agent, wherein
the binder resin comprises at least an amorphous resin and an urethane modified crystalline resin comprising a crystalline polymer segment and an urethane polymer segment bound to each other, the urethane modified crystalline resin being non-compatible with the amorphous resin, and
the amount of an ionic dissociating group of the urethane modified crystalline resin is 5 to 20 mgKOH/g.

2. The toner for electrostatic charge image development according to claim 1 , wherein the following relational formula (1) is satisfied when a glass transition point of the amorphous resin is TgA, a melting point of the urethane modified crystalline resin is TmC, and a melting point of the releasing agent is TmW:
TgA≦TmC<TmW.   Relational formula (1)

3. The toner for electrostatic charge image development according to claim 1 , wherein the following relational formula (2) and the relational formula (3) are satisfied when an endothermic amount of the toner for electrostatic charge image development, which is based on an endothermic peak derived from the urethane modified crystalline resin during a first temperature increasing process for increasing the temperature from 0° C. to 200° C. in differential scanning calorimetry, is ΔH1 (J/g), an endothermic amount of the toner for electrostatic charge image development, which is based on an endothermic peak derived from the urethane modified crystalline resin during a second temperature increasing process for increasing the temperature from 0° C. to 200° C. in the differential scanning calorimetry, is ΔH2 (J/g), an endothermic amount of the urethane modified crystalline resin only, which is based on an endothermic peak during the second temperature increasing process for increasing the temperature from 0° C. to 200° C. in differential scanning calorimetry, is ΔH0 (J/g), and a content ratio of the urethane modified crystalline resin in the toner particles is A (% by mass):
0.75≦Δ H 1/(Δ H 0×( A/ 100))≦1.0  Relational formula (2)

0.75≦Δ H 2/Δ H 1≦1.0.  Relational formula (3)

4. The toner for electrostatic charge image development according to claim 1 , wherein a carboxylic acid group and/or a sulfonic acid group is comprised at a molecular terminal of the urethane modified crystalline resin and/or in the urethane polymer segment constituting the urethane modified crystalline resin.

5. The toner for electrostatic charge image development according to claim 1 , wherein the peak temperature of an endothermic peak derived from the urethane modified crystalline resin during a second temperature increasing process for increasing the temperature from 0° C. to 200° C. in differential scanning calorimetry of the urethane modified crystalline resin only is in the range of 50 to 85° C.

6. The toner for electrostatic charge image development according to claim 1 , wherein the crystalline polymer segment constituting the urethane modified crystalline resin comprises a crystalline polyester polymer.

7. The toner for electrostatic charge image development according to claim 1 , wherein the amorphous resin is a styrene acrylic resin and/or a polyester resin.

8. A method for manufacturing a toner for electrostatic charge image development comprising toner particles comprising a binder resin, a colorant, and a releasing agent, the method comprising:
aggregating and fusing microparticles comprising an amorphous resin for forming the binder resin and microparticles comprising an urethane modified crystalline resin for forming the binder resin, which is obtained by binding a crystalline polymer segment and an urethane polymer segment and is non-compatible with the amorphous resin, the microparticles being dispersed in an aqueous medium, and
using, as the urethane modified crystalline resin, a resin having an ionic dissociating group amount of 5 to 20 mgKOH/g.

Assignees

• Konica Minolta Inc

Inventors

• Kouyama Mikio
• Fujisaki Natsuko
• Matsushima Asao
• Ohmura Ken
• Nagase Tatsuya

Classifications

• G03G9/08764 Primary

  Polyureas; Polyurethanes · CPC title

• G03G9/08795

  characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants · CPC title

• G03G9/08797

  characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature · CPC title