US 2026/0147287 A1Published application

Two-component developer

OwnerIchiro Kanno, Kentaro Kamae +6inventors

InventorsICHIRO KANNO, KENTARO KAMAE, NOBUHIRO YOSHIDA, MIZUKI SAITO, KOHEI YOSHIYAMA, YUU NISHIMURA, TORU TAKAHASHI, TAKAHO SHIBATA

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Abstract

A two-component developer includes a toner particle, a magnetic carrier particle, and an inorganic fine particle B. The magnetic carrier particle includes a coating resin layer coating a magnetic core particle and including an inorganic fine particle A. At least part of the inorganic fine particle A is exposed on the carrier particle surface. A recovery amount XB of the inorganic fine particle B recovered by a water washing method is 0.01 to 0.05 parts by mass. The inorganic fine particle B has a compression energy of 75 mJ or less. The inorganic fine particles A and B satisfy designated relationship.

Claims5

Dependent claims

A two-component developer comprising:

a toner particle;
a magnetic carrier particle;
and
an inorganic fine particle B,
wherein the magnetic carrier particle includes a magnetic core particle and a coating resin layer coating a surface of the magnetic core particle,
the coating resin layer includes an inorganic fine particle A,
at least part of the inorganic fine particle A is exposed on a surface of the magnetic carrier particle,
XB (parts by mass) representing a recovery amount of the inorganic fine particle B recovered from the two-component developer by a water washing method is 0.01 parts by mass to 0.05 parts by mass per 100 parts by mass of the magnetic carrier particle,
the inorganic fine particle B has a compression energy of 75 mJ or less as measured in a state of a powder layer formed by compression at 30 kPa,
WA (eV) representing a work function of the inorganic fine particle A and WB (eV) representing a work function of the inorganic fine particle B satisfy formula (1):
0.5
≤
❘
"\[LeftBracketingBar]"
WA
-
WB
❘
"\[RightBracketingBar]"
≤
10.
,
(
1
)
XA (area %) representing a coverage of the surface of the magnetic carrier particle by the inorganic fine particle A and the XB satisfy formula (2):
0.001
≤
XB
/
XA
≤
0
.
0
⁢
10
,
(
2
)
and
HA (nm) representing an average value of a height of a protrusion of the inorganic fine particle A exposed on the surface of the magnetic carrier particle and HB (nm) representing a number average particle diameter of primary particles of the inorganic fine particle B recovered by the water washing method satisfy formula (3):
0.5
≤
HB
/
HA
≤
4.
.
(
3
)

51 more elements

A method for producing a two-component developer, the method comprising:

a step of obtaining a toner particle mixture by mixing a toner particle and an external additive other than an inorganic fine particle B;
a step of obtaining a toner by mixing the toner particle mixture and the inorganic fine particle B;
and
a step of obtaining a two-component developer by mixing the toner and a magnetic carrier particle,
wherein the obtained two-component developer includes the toner particle, the magnetic carrier particle, and the inorganic fine particle B,
the magnetic carrier particle contains a magnetic core particle and a coating resin layer coating a surface of the magnetic core particle,
the coating resin layer includes an inorganic fine particle A,
at least part of the inorganic fine particle A is exposed on a surface of the magnetic carrier particle,
XB (parts by mass) representing a recovery amount of the inorganic fine particle B recovered from the two-component developer by a water washing method is 0.01 parts by mass to 0.05 parts by mass per 100 parts by mass of the magnetic carrier particle,
the inorganic fine particle B has a compression energy of 75 mJ or less as measured in a state of a powder layer formed by compression at 30 kPa,
WA (eV) representing a work function of the inorganic fine particle A and WB (eV) representing a work function of the inorganic fine particle B satisfy formula (1):
0.5
≤
❘
"\[LeftBracketingBar]"
WA
-
WB
❘
"\[RightBracketingBar]"
≤
10.
(
1
)
XA (area %) representing a coverage of the surface of the magnetic carrier particle by the inorganic fine particle A and the XB satisfy formula (2):
0.001
≤
XB
/
XA
≤
0
.
0
⁢
10
,
(
2
)
and
HA (nm) representing an average value of a height of a protrusion of the inorganic fine particle A exposed on the surface of the magnetic carrier particle and HB (nm) representing a number average particle diameter of primary particles of the inorganic fine particle B recovered by the water washing method satisfy formula (3):
0.5
≤
HB
/
HA
≤
4.
.
(
3
)

51 more elements

Dependencies are inferred from the claim text.