Toner

Patent metadata

Field	Value
Publication number	US-9946181-B2
Application number	US-201715586732-A
Country	US
Kind code	B2
Filing date	May 4, 2017
Priority date	May 20, 2016
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

A toner comprises toner particles, each of which contains a binder resin, a colorant, a wax and a crystalline polyester. The melting point P(t) of the crystalline polyester is at least 65.0° C. and not more than 80.0° C., and regarding a storage elastic modulus G′ obtained in dynamic viscoelasticity measurement of the toner, where G′ at 50° C. is denoted by G′(50), G′ at 80° C. is denoted by G′(80), G′ at 120° C. is denoted by G′(120), and G′ at the melting point P(t) of the crystalline polyester is denoted by G′(t), the following formulas are satisfied: 4.2×10 8 Pa≤G′(50), 3.0×10 2 ≤G′(50)/G′(80), and G′(t)/G′(120)≤7.0×10 2 .

First claim

What is claimed is:

1. A toner comprising toner particles, each of which contains a binder resin, a colorant, a wax and a crystalline polyester, wherein
a melting point P(t) of the crystalline polyester is at least 65.0° C. and not more than 80.0° C.; and
regarding a storage elastic modulus G′ obtained in dynamic viscoelasticity measurement of the toner, where
G′ at 50° C. is denoted by G′(50),
G′ at 80° C. is denoted by G′(80),
G′ at 120° C. is denoted by G′(120), and
G′ at the melting point P(t) of the crystalline polyester is denoted by G′(t),
all of the following formulas (1) to (3) are satisfied:
4.2×10 8 Pa ≤G ′(50)  (1)

3.0×10 2 ≤G ′(50)/ G ′(80)  (2)

G ′( t )/ G ′(120)≤7.0×10 2   (3).

2. The toner according to claim 1 , wherein
a content of the crystalline polyester is at least 3.0 parts by mass and not more than 15.0 parts by mass with respect to 100 parts by mass of the binder resin; and
the ratio of the content of the crystalline polyester to the content of the wax is at least 0.30 and not more than 1.00 on a mass basis.

3. The toner according to claim 1 , wherein
where a melting point of the wax is denoted by W(t) and the melting point of the crystalline polyester is denoted by P(t), the W(t) and the P(t) satisfy the following formula (4):
−10.0° C.≤{ W ( T )− P ( t )}≤20.0° C.  (4).

4. The toner according to claim 1 , wherein
the binder resin includes a styrene acrylic resin; and
the content of the styrene acrylic resin in the binder resin is at least 50% by mass and not more than 100% by mass.

5. The toner according to claim 1 , wherein the wax includes an ester wax.

6. The toner according to claim 1 , wherein
in cross-sectional observations of each of the toner particles under a scanning transmission electron microscope,
domains of the crystalline polyester are present in a cross section of each of the toner particles;
a number-average long diameter of the domains of the crystalline polyester is at least 5 nm and not more than 500 nm; and
the number of domains of the crystalline polyester per cross section of each of the toner particles is at least 8 and not more than 500.

7. The toner according to claim 1 , wherein
in cross-sectional observations of each of the toner particles under a scanning transmission electron microscope,
a domain of the wax is present in a cross section of each of the toner particles;
a maximum diameter of the domain of the wax is at least 1.0 μm and not more than 5.0 μm; and
a proportion of an area of the domain of the wax to an area of the cross section of each of the toner particles is at least 10.0% by area and not more than 60.0% by area.

8. The toner according to claim 1 , wherein
the crystalline polyester is a polyester having a structure derived from an acid monomer selected from lauric acid, stearic acid, and behenic acid at a molecular chain end.

Assignees

• Canon Kk

Inventors

• Hasegawa Yusuke
• Sano Tomohisa
• Suzumura Yoshitaka
• Ikejiri Takuma
• Yamashita Shohei

Classifications

• G03G9/0926

  characterised by physical or chemical properties · CPC title

• G03G9/08711

  with esters of acrylic or methacrylic acid · CPC title

• G03G9/0904

  Carbon black · CPC title

• G03G9/0819

  characterised by the dimensions of the particles · CPC title

• G03G9/08755 Primary

  Polyesters · CPC title