Electrostatic charge image developing toner

Patent metadata

Field	Value
Publication number	US-2017255119-A1
Application number	US-201715440167-A
Country	US
Kind code	A1
Filing date	Feb 23, 2017
Priority date	Mar 2, 2016
Publication date	Sep 7, 2017
Grant date	—

Abstract

An electrostatic charge image developing toner includes a toner matrix particle having a core-shell structure. The toner matrix particle contains: a core particle including an amorphous resin, a colorant, a release agent, and a crystalline resin; and a shell layer coating a surface of the core particle at a coverage of 60 to 99%. The shell layer includes an amorphous resin. The amorphous resin contained in the core particle differs from the amorphous resin contained in the shell layer. The toner matrix particle has one to seven discrete shell domains determined by observation of a cross section of the toner matrix particle with an electron microscope.

First claim

What is claimed is:

1 . An electrostatic charge image developing toner comprising a toner matrix particle having a core-shell structure, wherein
the toner matrix particle contains: a core particle including an amorphous resin, a colorant, a release agent, and a crystalline resin; and a shell layer coating a surface of the core particle at a coverage of 60 to 99%, the shell layer includes an amorphous resin, the amorphous resin contained in the core particle differs from the amorphous resin contained in the shell layer, and the toner matrix particle has one to seven discrete shell domains determined by observation of a cross section of the toner matrix particle with an electron microscope.

2 . The electrostatic charge image developing toner of claim 1 , wherein a content of the crystalline resin is 5 to 40 parts by mass.

3 . The electrostatic charge image developing toner of claim 1 , wherein the amorphous resin contained in the shell layer is a hybrid resin including a segment of an amorphous resin similar to the amorphous resin contained in the toner particle, the segment molecularly bonding to the amorphous resin contained in the core particle.

4 . The electrostatic charge image developing toner of claim 1 , wherein the amorphous resin contained in the shell layer is an amorphous polyester resin.

5 . The electrostatic charge image developing toner of claim 1 , wherein the amorphous resin contained in the core particle is a styrene-acrylic resin.

6 . The electrostatic charge image developing toner of claim 4 , wherein the amorphous polyester resin contained in the shell layer includes a styrene-acrylic modified polyester having a structure including a polyester molecular chain molecularly bonded to a styrene-acrylic copolymer molecular chain.

7 . The electrostatic charge image developing toner of claim 1 , wherein the crystalline resin is a crystalline polyester resin.

8 . The electrostatic charge image developing toner of claim 1 , wherein each of the shell domains is in a continuous phase.

9 . The electrostatic charge image developing toner of claim 1 , wherein the shell layer coats the surface of the core particle at a coverage of 80 to 90%.

10 . The electrostatic charge image developing toner of claim 1 , wherein a following expression is satisfied:
an average of lengths L is equal to or greater than 1/8 of a perimeter of the core particle, where L represents a length of an interface between the core particle and a shell domain determined by observation of a cross section of the toner matrix particle.

11 . The electrostatic charge image developing toner of claim 1 , wherein a shape factor SF-2 of the toner matrix particle and a shape factor SF-2 of the core particle satisfy Expression (1):
the shape factor SF-2 of the core particle>the shape factor SF-2 of the toner matrix particle.  Expression (1):

Assignees

• Konica Minolta Inc

Inventors

• Iioka Atsushi
• Kayamori Takanari
• Tonegawa Naoya
• Matsubara Masaharu
• Sekiguchi Kouji

Classifications

• G03G9/0825 Primary

  characterised by their structure; characterised by non-homogenuous distribution of components (microcapsular toners G03G9/093) · CPC title

• G03G9/09328

  obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• G03G9/0819

  characterised by the dimensions of the particles · CPC title

• G03G9/0827

  characterised by their shape, e.g. degree of sphericity · CPC title

• G03G9/09321

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title