IP Library Granted Patent US 12,681,404
Granted Patent B2
US 12,681,404 · App. 18/190,065 · Granted Jul 14, 2026

Electrostatic charge image developing toner, electrostatic charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method

Inventors: Yasuko Torii (Kanagawa, JP); Yosuke Tsurumi (Kanagawa, JP); Soichiro Arai (Kanagawa, JP)
Assignee: FUJIFILM Business Innovation Corp
G03G9/09725G03G9/0819G03G9/08711G03G15/0865
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 12,681,404
App. No.
18/190,065
Granted
Jul 14, 2026
Kind
B2
Abstract

An electrostatic charge image developing toner contains toner particles that contain a binder resin and resin particles and silica particles (A) that are externally added to the toner particles and contain a nitrogen element-containing compound containing a molybdenum element, in which a ratio N Mo /N Si of Net intensity N Mo of the molybdenum element measured by X-ray fluorescence analysis to Net intensity N Si of a silicon element measured by X-ray fluorescence analysis is 0.035 or more and 0.45 or less.

Claims (41)

1 . An electrostatic charge image developing toner comprising:

toner particles that contain a binder resin and resin particles, wherein the binder resin is a polyester resin, and the resin particles are crosslinked vinyl-based resin particles; and

silica particles (A) that are externally added to the toner particles and contain a nitrogen element-containing compound containing a molybdenum element, in which a ratio N Mo /N Si of Net intensity N Mo of the molybdenum element measured by X-ray fluorescence analysis to Net intensity N Si of a silicon element measured by X-ray fluorescence analysis is 0.035 or more and 0.45 or less.

2 . The electrostatic charge image developing toner according to claim 1 ,

wherein the ratio N Mo /N Si of the silica particles (A) is 0.05 or more and 0.30 or less.

3 . The electrostatic charge image developing toner according to claim 1 ,

wherein a ratio Dp/Da of an average particle size Dp of the resin particles to an average primary particle size Da of the silica particles (A) is 0.75 or more and 15 or less.

4 . The electrostatic charge image developing toner according to claim 1 ,

wherein the crosslinked vinyl-based resin particles are styrene (meth)acrylic resin particles.

5 . The electrostatic charge image developing toner according to claim 1 , further comprising:

silica particles (B) other than the silica particles (A), that are externally added to the toner particles.

6 . The electrostatic charge image developing toner according to claim 1 , further comprising:

strontium titanate particles externally added to the toner particles.

7 . The electrostatic charge image developing toner according to claim 6 ,

wherein an average primary particle size of the strontium titanate particles is 25 nm or more and 80 nm or less.

8 . The electrostatic charge image developing toner according to claim 6 ,

wherein a mass-based ratio M2/M1 of a content M2 of the strontium titanate particles to a content M1 of the silica particles (A) is 0.5 or more and 1.5 or less.

9 . The electrostatic charge image developing toner according to claim 1 ,

wherein a surface coverage C1 by the silica particles (A) in the toner particles is 10% or more and 60% or less.

10 . The electrostatic charge image developing toner according to claim 1 , further comprising:

inorganic particles other than the silica particles (A), that are externally added to the toner particles,

wherein, in the toner particles, a ratio C1/C2 of a surface coverage C1 by the silica particles (A) to a surface coverage C2 by inorganic particles having a primary particle size of 80 nm or more and 150 nm or less among the inorganic particles is 0.2 or more and 1.5 or less.

11 . The electrostatic charge image developing toner according to claim 1 ,

wherein an amount of a liberated oil contained in the electrostatic charge image developing toner is 0.01% by mass or more and 0.1% by mass or less with respect to an overall amount of the electrostatic charge image developing toner.

12 . The electrostatic charge image developing toner according to claim 1 ,

wherein the nitrogen element-containing compound containing a molybdenum element is at least one kind of compound selected from the group consisting of a quaternary ammonium salt containing a molybdenum element and a mixture of a quaternary ammonium salt and a metal oxide containing a molybdenum element.

13 . The electrostatic charge image developing toner according to claim 1 ,

wherein the silica particles (A) are silica particles having a coating structure that consists of a reaction product of a silane coupling agent and the nitrogen element-containing compound containing a molybdenum element that has adhered to the coating structure.

14 . The electrostatic charge image developing toner according to claim 1 ,

wherein in a case where a loss tangent tan δ of the electrostatic charge image developing toner determined by dynamic viscoelasticity measurement at a temperature of 90° C. and a strain of 1% is represented by D1 (90), a loss tangent tan δ of the electrostatic charge image developing toner determined by dynamic viscoelasticity measurement at a temperature of 90° C. and a strain of 50% is represented by D50 (90), a loss tangent tan δ of the electrostatic charge image developing toner determined by dynamic viscoelasticity measurement at a temperature of 150° C. and a strain of 1% is represented by D1 (150), and a loss tangent tan δ of the electrostatic charge image developing toner determined by dynamic viscoelasticity measurement at a temperature of 150° C. and a strain of 50% is represented by D50 (150),

each of D1 (90), D50 (90), D1 (150), and D50 (150) is 0.5 or more and 2.5 or less,

a value of D50 (150)−D1 (150) is less than 1.5, and

a value of D50 (90)−D1 (90) is less than 1.0.

15 . An electrostatic charge image developer comprising:

the electrostatic charge image developing toner according to claim 1 .

16 . An image forming method comprising:

charging a surface of an image holder;

forming an electrostatic charge image on the charged surface of the image holder;

developing the electrostatic charge image formed on the surface of the image holder as a toner image by using the electrostatic charge image developer according to claim 15 ;

transferring the toner image formed on the surface of the image holder to a surface of a recording medium; and

fixing the toner image transferred to the surface of the recording medium.