Semiconductive resin composition, member for electrophotography and image forming apparatus

Patent metadata

Field	Value
Publication number	US-9921526-B2
Application number	US-201514967827-A
Country	US
Kind code	B2
Filing date	Dec 14, 2015
Priority date	Jan 9, 2015
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

A semiconductive resin composition includes at least two thermoplastic resins and a conductive filler. Each of the two thermoplastic resins has a sea-island structure, and 40% to 75% of the conductive filler are present in the thermoplastic resin in an island portion of the sea-island structure at an areal ratio of a cross section observed with a scanning electron microscope.

First claim

What is claimed is:

1. A semiconductive resin composition, comprising:
at least two thermoplastic resins; and
a conductive filler,
wherein the two thermoplastic resins form a sea-island structure in which one of the two thermoplastic resins forms a sea portion and another of the two thermoplastic resins forms one or more island portions, and in a cross section observed with a scanning electron microscope, an abundance ratio of the conductive filler in the one or more island portions of the sea-island structure to that in the sea portion and the one or more island portions is 40% to 75%.

2. The semiconductive resin composition of claim 1 , wherein the following relation is satisfied:
Tc 1< Tc 2
wherein Tc1 represents a crystallization temperature of the thermoplastic resin in the sea portion of the sea-island structure and Tc2 represents a crystallization temperature of the thermoplastic resin in the one or more island portions thereof.

3. The semiconductive resin composition of claim 2 , wherein a difference between Tc2 and Tc1 (Tc2−Tc1) is not less than 5° C.

4. The semiconductive resin composition of claim 1 , wherein the following relation is satisfied:
γ2−γ1≥30 mJ/m2

wherein γ1 represents a surface free energy of the thermoplastic resin in the sea portion of the sea-island structure and γ2 represents a surface free energy of the thermoplastic resin in the one or more island portions thereof.

5. The semiconductive resin composition of claim 1 , wherein the conductive filler is carbon black.

6. The semiconductive resin composition of claim 5 , wherein the carbon black has an average primary particle diameter of from 10 nm to 40 nm.

7. The semiconductive resin composition of claim 5 , wherein the carbon black has a DBP oil absorption not greater than 200 cm 3 /100 g.

8. A seamless belt member for electrophotography, comprising a semiconductive resin composition comprising:
at least two thermoplastic resins; and
a conductive filler,
wherein the two thermoplastic resins form a sea-island structure in which one of the two thermoplastic resins forms a sea portion and another of the two thermoplastic resins forms one or more island portions, and
wherein the sea-island structure is configured to decrease variation of resistance in the seamless belt member, and in a cross section observed with a scanning electron microscope, an abundance ratio of the conductive filler in the one or more island portions of the sea-island structure to that in the sea portion and the one or more island portions is 40% to 75%.

9. An image forming apparatus, comprising:
an electrostatic latent image bearer;
an electrostatic latent image former to form an electrostatic latent image on the electrostatic latent image bearer;
an image developer to develop the electrostatic latent image with a toner to form a visible image;
a transferer to transfer the visible image onto a recording medium; and
a seamless belt member for electrophotography, comprising a semiconductive resin composition comprising:
at least two thermoplastic resins; and
a conductive filler,
wherein the two thermoplastic resins form a sea-island structure in which one of the two thermoplastic resins forms a sea portion and another of the two thermoplastic resins forms one or more island portions, and
wherein the sea-island structure is configured to decrease variation of resistance in the seamless belt member, and in a cross section observed with a scanning electron microscope, an abundance ratio of the conductive filler in the one or more island portions of the sea-island structure to that in the sea portion and the one or more island portions is 40% to 75%.

Assignees

• Takahashi Hiroaki
• Yasunaga Hideaki
• Izutani Akira
• Matsushita Makoto
• Juri Keiichiro
• Haga Yuri
• Momose Ayano
• Ricoh Co Ltd

Inventors

• Takahashi Hiroaki
• Yasunaga Hideaki
• Izutani Akira
• Matsushita Makoto
• Juri Keiichiro
• Haga Yuri
• Momose Ayano

Classifications

• G03G9/0825

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

• G03G15/162 Primary

  details of the the intermediate support, e.g. chemical composition · CPC title

• G03G15/1685

  Structure, details of the transfer member, e.g. chemical composition · CPC title

• H01B1/24

  the conductive material comprising carbon-silicon compounds, carbon or silicon · CPC title