Pigment dispersion and toner

Patent metadata

Field	Value
Publication number	US-2023176495-A1
Application number	US-202218058948-A
Country	US
Kind code	A1
Filing date	Nov 28, 2022
Priority date	Dec 3, 2021
Publication date	Jun 8, 2023
Grant date	—

Abstract

The pigment dispersion is a pigment dispersion including a fluorescent agent, wherein, when at a wavelength of 250 nm or more and 290 nm or less, an integral value of an emission intensity in a wavelength range of 400 nm or more and 700 nm or less of an emission spectrum of the fluorescent agent for excitation light is represented by F1, an integral value of an emission intensity in a wavelength range of 400 nm or more and 700 nm or less of an emission spectrum of the pigment dispersion for excitation light is represented by F2, and a ratio of the fluorescent agent contained in a solid content obtained when the pigment dispersion is heated at 130° C. until a change in mass of the pigment dispersion reaches 0.3%/min or less is represented by W1 (mass%), the F1, the F2, and the W1 satisfy the formulae F2x 100/W1≥F1 ×0.30 and 5.0≤W1≤80.0.

First claim

What is claimed is:

1 . A pigment dispersion comprising a fluorescent agent and a binder resin,
wherein the fluorescent agent is excited with light at a wavelength of 400 nm or less, wherein, when an integral value of an emission intensity in a wavelength range of 400 nm or more and 700 nm or less of an emission spectrum of the fluorescent agent for excitation light at a wavelength of 250 nm or more and 290 nm or less is represented by F1, an integral value of an emission intensity in a wavelength range of 400 nm or more and 700 nm or less of an emission spectrum of the pigment dispersion for excitation light at a wavelength of 250 nm or more and 290 nm or less is represented by F2, and a ratio of the fluorescent agent contained in a solid content obtained when the pigment dispersion is heated at 130° C. until a change in mass of the pigment dispersion reaches 0.3%/min or less is represented by W1 (mass%), the F1, the F2, and the W1 satisfy the following formulae (1) and (2). F2 × 100 / W1 ≥ F1 × 0 .30 5.0 ≤ W1 ≤ 80 .0
.

2 . The pigment dispersion according to claim 1 , wherein a maximum value (Rmax1) of a light absorptivity in the wavelength range of 400 nm or more and 700 nm or less in an image of the solid content formed of the pigment dispersion on a medium at a laid-on level of 0.3 mg/cm 2 is 10% or less.

3 . The pigment dispersion according to claim 1 , wherein the fluorescent agent is an inorganic compound containing a lanthanoid element and containing calcium fluoride as a main component.

4 . The pigment dispersion according to claim 1 , wherein, in a sectional observation image of the solid content of the pigment dispersion with a scanning electron microscope (SEM), the fluorescent agent has a 50% particle diameter on a number basis of 500 nm or less.

5 . The pigment dispersion according to claim 1 , wherein the W1 (mass%) satisfies the following formula (3).

30.0
≤
W1
≤
7
0
.0

.

6 . The pigment dispersion according to claim 1 , wherein the binder resin in the pigment dispersion contains one or more kinds of units selected from units each represented by any one of the following formulae (4) to (6), and a total content ratio of the units each represented by any one of the formulae (4) to (6) in a total mass of the binder resin is 70 mass% or more:
in the formula (4), P 1 and P 2 each represent a bonding site to a main chain skeleton of a resin, Ri represents a hydrogen atom or a methyl group, and “n” represents an integer of 0 or more and 30 or less; in the formula (5), P 3 and P 4 each represent a bonding site to the main chain skeleton of the resin; in the formula (6), P 5 and P 6 each represent a bonding site to the main chain skeleton of the resin.

7 . The pigment dispersion according to claim 6 ,
wherein the binder resin in the pigment dispersion contains the unit represented by the formula (4), and wherein the “n” in the formula (4) is 16 or more and 30 or less.

8 . The pigment dispersion according to claim 1 , wherein, when color coordinates obtained by transforming emission wavelength spectra of the pigment dispersion at a time of irradiation with excitation light at a wavelength of 250 nm or more and 290 nm or less and a wavelength of 315 nm or more and 400 nm or less into an L*a*b* color system are represented by G1 and G2, respectively, a difference ΔE1 between the color coordinates G1 and G2 is 20.0 or more.

9 . A toner comprising a toner particle containing a fluorescent agent that is excited with light at a wavelength of 400 nm or less, a binder resin, and a release agent,
wherein, when an integral value of an emission intensity in a wavelength range of 400 nm or more and 700 nm or less of an emission spectrum of the fluorescent agent for excitation light at a wavelength of 250 nm or more and 290 nm or less is represented by F3, an integral value of an emission intensity in a wavelength range of 400 nm or more and 700 nm or less of an emission spectrum of the toner for excitation light at a wavelength of 250 nm or more and 290 nm or less is represented by F4, and a mass ratio of the fluorescent agent in the toner particle is represented by W2 (mass%), the following formulae (7) and (8) are satisfied. F4 × 100 / W2 ≥ F3 × 0 .30 5.0 ≤ W2 ≤ 8 0 .0
.

10 . The toner according to claim 9 , wherein a maximum value (Rmax2) of a light absorptivity in the wavelength range of 400 nm or more and 700 nm or less in an image obtained by forming the toner on a medium at a laid-on level of 0.3 mg/cm 2 is 10% or less.

11 . The toner according to claim 9 , wherein the fluorescent agent is an inorganic compound containing a lanthanoid element and containing calcium fluoride as a main component.

12 . The toner according to claim 9 , wherein, in a sectional observation image of the toner particle with a scanning electron microscope (SEM), the toner particle has a 50% particle diameter on a number basis of 500 nm or less.

13 . The toner according to claim 9 , wherein the W2 satisfies the following formula (9).

30.0
≤
W2
≤
7
0
.0

.

14 . The toner according to claim 9 , wherein the binder resin in the toner particle contains one or more kinds of units selected from units each represented by any one of the following formulae (4) to (6), and a total content ratio of the units each represented by any one of the formulae (4) to (6) in a total mass of the binder resin is 70 mass% or more:
in the formula (4), P 1 and P 2 each represent a bonding site to a main chain skeleton of a resin, Ri represents a hydrogen atom or a methyl group, and “n” represents an integer of 0 or more and 30 or less; in the formula (5), P 3 and P 4 each represent a bonding site to the main chain skeleton of the resin; in the formula (6), P 5 and P 6 each represent a bonding site to the main chain skeleton of the resin.

15 . The toner according to claim 14 ,
wherein the binder resin in the toner particle contains the unit represented by the formula (4), and wherein the “n” in the formula (4) is 16 or more and 30 or less.

16 . The toner according to claim 9 , wherein, when color coordinates obtained by transforming emission wavelength spectra of the toner at a time of irradiation with excitation light at a wavelength of 250 nm or more and 290 nm or less and a wavelength of 315 nm or more and 400 nm or less into an L*a*b* color system are represented by G3 and G4, respectively, a difference ΔE2 between the color coordinates G3 and G4 is 20.0 or more.

Assignees

• Canon Kk

Inventors

• Yoshida Yu
• Nozaki Dai
• Takada Harumi
• Kuroki Shiro
• Toyoizumi Noritaka
• Mochizuki Shinsuke

Classifications

• G03G9/08755

  Polyesters · CPC title

• G03G9/0902

  Inorganic compounds · CPC title

• G03G9/0926 Primary

  characterised by physical or chemical properties · CPC title

• G03G9/0819

  characterised by the dimensions of the particles · CPC title

• G03G9/08757

  Polycarbonates · CPC title