Electrostatic image developing toner, developer, and image forming apparatus

Patent metadata

Field	Value
Publication number	US-9557671-B2
Application number	US-201514629954-A
Country	US
Kind code	B2
Filing date	Feb 24, 2015
Priority date	Mar 3, 2014
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

A toner, including: base particles containing a polyester resin, a colorant, and a release agent, wherein the toner has a glass transition temperature (Tg1st) of 20° C. to 50° C. where the glass transition temperature (Tg1st) is measured in first heating of differential scanning calorimetry (DSC) of the toner, wherein tetrahydrofuran (THF) insoluble matter of the toner has a glass transition temperature [Tg2nd (THF insoluble matter)] of 30° C. or lower where the glass transition temperature [Tg2nd (THF insoluble to matter)] is measured in second heating of differential scanning calorimetry (DSC) of the THF insoluble matter, and wherein 50% or less of the colorant is present within a region of 1,000 nm from a surface of each of the base particles toward a center thereof.

First claim

What is claimed is:

1. A toner, comprising:
base particles, comprising:
a noncrystalline nonlinear polyester resin (A) having at least one of a urethane and a urea bond and a glass transition temperature (T g ) of from −60° C. to 0° C.;
a noncrystalline polyester resin (B) having a T g of from 40 to 80° C.;
a crystalline polyester resin (C) having a melting point of from 60 to 80° C.;
a colorant dispersing resin;
a colorant, and a release agent,
wherein the toner has a glass transition temperature (Tg1st) of 20° C. to 50° C. where the glass transition temperature (Tg1st) is measured in first heating of differential scanning calorimetry (DSC) of the toner,
wherein a tetrahydrofuran (THF) insoluble matter of the toner has a glass transition temperature [Tg2nd(THF insoluble matter)] of 30° C. or lower where the glass transition temperature [Tg2nd(THF insoluble matter)] is measured in second heating of differential scanning calorimetry (DSC) of the THF insoluble matter, and
wherein 50% or less of the colorant is present within a region of 1,000 nm from a surface of each of the base particles toward a center thereof.

2. The toner according to claim 1 ,
wherein a solution containing the colorant dispersing resin dissolved in ethyl acetate having a solid content of 20% by mass satisfies the expressions:
T (60)%− T (480)%≧30%,

and
T(480)% is 50% or less,

where the T(60)% is a transmittance of the solution at an optical path length of 1 cm after the solution has been left for 60 minutes, and the T(480)% is a transmittance of the solution at an optical path length of 1 cm after the solution has been left for 480 minutes.

3. The toner according to claim 2 , wherein the T(60) % is 30% or more.

4. The toner according to claim 1 , wherein an amine value of the colorant is 2 mgKOH/g or less.

5. The toner according to claim 1 , wherein the colorant comprises Pigment Red 269.

6. The toner according to claim 1 , wherein a [G′(100) (THF insoluble matter)] is 1.0×10 5 Pa to 1.0×10 7 Pa where the [G′(100) (THF insoluble matter)] is a storage modulus at 100° C. of the THF insoluble matter.

7. The toner according to claim 1 , wherein a ratio of [G′(40) (THF insoluble matter)] to the [G(100) (THF insoluble matter) ], which is represented by [G′(40) (THF insoluble matter)]/[G′(100) (THF insoluble matter)], is 3.5×10 or less, where the [G′(40) (THF insoluble matter)] is a storage modulus at 40° C. of the THF insoluble matter and the [G′(100) (THF insoluble matter)] is a storage modulus at 100° C. of the THF insoluble matter.

8. The toner according to claim 1 , wherein the toner has a glass transition temperature (Tg2nd) of 0° C. to 30° C. where the glass transition temperature (Tg2nd) is measured in second heating of differential scanning calorimetry (DSC) of the toner.

9. The toner according to claim 6 , wherein the [G′(100) (THF insoluble matter)] is 5.0×10 5 Pa to 5.0×10 6 Pa.

10. The toner according to claim 1 , wherein the non-crystalline polyester resin A comprises a crosslinked structure.

11. A developer, comprising:
a toner: and
a carrier,
wherein the toner comprises:
base particles, comprising:
a noncrystalline nonlinear polyester resin (A) having at least one of a urethane and a urea bond and a glass transition temperature (T g ) of from −60° C. to 0° C.;
a noncrystalline polyester resin (B) having a T g of from 40 to 80° C.;
a crystalline polyester resin (C) having a melting point of from 60 to 80° C.;
a colorant dispersing resin;
a colorant, and a release agent,
wherein the toner has a glass transition temperature (Tg1 st) of 20° C. to 50° C. where the glass transition temperature (Tg1st) is measured in first heating of differential scanning calorimetry (DSC) of the toner,
wherein tetrahydrofuran (THF) insoluble matter of the toner has a glass transition temperature [Tg2nd (THF insoluble matter)] of 30° C. or lower where the glass transition temperature [Tg2nd (THF insoluble matter)] is measured in second heating of differential scanning calorimetry (DSC) of the THF insoluble matter, and
wherein 50% or less of the colorant is present within a region of 1,000 nm from a surface of each of the base particles toward a center thereof.

12. An image forming apparatus, comprising:
an electrostatic latent image bearer;
an electrostatic latent image forming unit configured to form an electrostatic latent image on the electrostatic latent image bearer; and
a developing unit containing a toner and configured to develop the electrostatic latent image formed on the electrostatic latent image bearer with the toner to form a visible image,
an image transfer device, and
a fixing device,
wherein the toner comprises:
base particles, comprising:
a noncrystalline nonlinear polyester resin (A) having at least one of a urethane and a urea bond and a glass transition temperature (T g ) of from −60° C. to 0° C.;
a noncrystalline polyester resin (B) having a T g , of from 40 to 80° C.;
a crystalline polyester resin (C) having a melting point of from 60 to 80° C.;
a colorant dispersing resin;
a colorant, and a release agent,
wherein the toner has a glass transition temperature (Tg1st) of 20° C. to 50° C. where the glass transition temperature (Tg1st) is measured in first heating of differential scanning calorimetry (DSC) of the toner,
wherein tetrahydrofuran (THF) insoluble matter of the toner has a glass transition temperature [Tg2nd (THF insoluble matter)] of 30° C. or lower where the glass transition temperature [Tg2nd (THF insoluble matter)] is measured in second heating of differential scanning calorimetry (DSC) of the THF insoluble matter, and
wherein 50% or less of the colorant is present within a region of 1,000 nm from a surface of each of the base particles toward a center thereof.

13. The toner of claim 1 , wherein non-crystalline polyester resin A comprises a trihydric or higher aliphatic alcohol as a constituent component.

14. The toner of claim 1 , wherein an amount of the non-crystalline polyester resin A is from 5 parts by mass to 25 parts by mass relative to 100 parts by mass of the toner.

15. The toner of claim 1 , wherein the non-crystalline polyester resin B comprises a dicarboxylic acid component as a constituent component, and
the dicarboxylic acid component comprises 50% by mole or more of an aromatic dicarboxylic acid.

16. The toner of claim 1 , wherein an amount of the non-crystalline polyester resin B is from 50 parts by mass to 90 parts by mass, relative to 100 parts by mass of the toner.

17. The toner of claim 1 , wherein an amount of the crystalline polyester resin C is from 3 parts by mass to 20 parts by mass, relative to 100 parts by mass of the toner.

Assignees

• Chiba Ryuta
• Nakayama Shinya
• Yamada Hiroshi
• Masuda Minoru
• Saitoh Akinori
• Santo Hideyuki
• Nagai Shinsuke
• Takeyama Akihiro
• Takeda Hiroyuki
• Sugimoto Tsuyoshi
• Amemori Suzuka
• Nagata kohsuke
• Ricoh Co Ltd

Inventors

• Chiba Ryuta
• Nakayama Shinya
• Yamada Hiroshi
• Masuda Minoru
• Saitoh Akinori
• Santo Hideyuki
• Nagai Shinsuke
• Takeyama Akihiro
• Takeda Hiroyuki
• Sugimoto Tsuyoshi
• Amemori Suzuka
• Nagata kohsuke

Classifications

• G03G9/08755 Primary

  Polyesters · CPC title

• G03G9/08797

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

• G03G9/0906

  Organic dyes · CPC title

• G03G9/08782

  Waxes · CPC title

• G03G9/08795

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