# US 2025/0147445 A1 · Charging roll for electrophotographic apparatus

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- Number: US 2025/0147445 A1
- Document ID: US20250147445A1
- Status: Published application
- Kind: A1
- Application number: 19/012,927
- Filed: 2025-01-08
- Published: 2025-05-08
- Earliest claimed: 2022-09-28
- Assignees: Sumitomo Riko Company Limited
- Applicants: Sumitomo Riko Company Limited
- Inventors: Junichiro Suenaga; Shinkichi Kashihara; Akitoshi Morita; Takeru Horiuchi
- Web page: https://patentgrep.com/patent/US20250147445A1

## CPC

- G03G 15/0233: {Structure, details of the charging member, e.g. chemical composition, surface properties}
- C08K 5/19: Quaternary ammonium compounds
- C08K 5/3442: having two nitrogen atoms in the ring
- C08K 5/42: Sulfonic acids; Derivatives thereof
- C08K 5/49: Phosphorus-containing compounds {(C08K5/0091 takes precedence)}
- C08L 15/02: Rubber derivatives containing halogen
- G03G 15/02: for laying down a uniform charge, e.g. for sensitising; Corona discharge devices (G03G15/14 takes precedence)
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

A charging roll for an electrophotographic apparatus includes a shaft body and an elastic body layer formed on an outer circumferential surface of the shaft body. The elastic body layer contains (a) to (c) below: (a) a hydrin rubber with a chlorine content of 14% or more and 19% or less; (b) an ionic conductive agent; and (c) a salt of a cyclic amidine compound. The hydrin rubber includes a crosslinking agent which is a sulfur crosslinking agent or a peroxide crosslinking agent.

## Claims

### Claim 1

A charging roll for an electrophotographic apparatus comprising a shaft body and an elastic body layer formed on an outer circumferential surface of the shaft body, wherein
the elastic body layer contains (a) to (c) below:
(a) a hydrin rubber with a chlorine content of 14% or more and 19% or less;
(b) an ionic conductive agent; and
(c) a salt of a cyclic amidine compound, and
the hydrin rubber comprises a crosslinking agent which is a sulfur crosslinking agent or a peroxide crosslinking agent.

### Claim 2 (depends on 1)

The charging roll for an electrophotographic apparatus according to claim 1, wherein the (c) is a naphthoic acid salt of a cyclic amidine compound.

### Claim 3 (depends on 1)

The charging roll for an electrophotographic apparatus according to claim 1, wherein the (c) is included in a content of 0.1 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the (a).

### Claim 4 (depends on 1)

The charging roll for an electrophotographic apparatus according to claim 1, wherein the (b) is included in a content of 0.5 parts by mass or more and 3.0 parts by mass or less with respect to 100 parts by mass of the (a).

### Claim 5 (depends on 1)

The charging roll for an electrophotographic apparatus according to claim 1, wherein the (b) is an ammonium-based, phosphonium-based, or imidazolium-based ionic conductive agent.

### Claim 6 (depends on 1)

The charging roll for an electrophotographic apparatus according to claim 1, wherein the (b) is an ionic conductive agent comprising a sulfonate anion having a fluorine atom, a bis(sulfonyl)imide anion having a fluorine atom, or a perchlorate anion.