Resin for toner and toner

• US 9,696,644 B2
• Filed: 04/08/2014
• Issued: 07/04/2017
• Est. Priority Date: 04/09/2013
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Shibata, Takaho, Ida, Hayato, Tamura, Junichi, Chimoto, Yuya, Hirasa, Takashi, Yamashita, Daisuke
• Primary Examiner(s): Boykin, Terressa
• Application Number:
  US14/768,301
• Publication Number:
  US 20150362853A1
• Time in Patent Office: 1,183 Days
• Field of Search: 528271, 528272, 528298
• CPC Class Codes: C08G 63/00 Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule polyester-amides C08G69/44; polyester-imides C08G73/16
• CPC Class Codes: C08G 63/181 Acids containing aromatic rings
• CPC Class Codes: C08G 63/189 containing a naphthalene ring
• CPC Class Codes: C08J 2367/00 Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain of polyester-amides C08J2377/12; of polyester-imides C08J2379/08; Derivatives of such polymers
• CPC Class Codes: C08J 2367/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds; C08J2367/06 takes precedence
• CPC Class Codes: C08J 3/12 Powdering or granulating
• CPC Class Codes: G03G 9/0804 whereby the components are brought together in a liquid dispersing medium
• CPC Class Codes: G03G 9/0806 whereby chemical synthesis of at least one of the toner components takes place
• CPC Class Codes: G03G 9/08755 Polyesters
• CPC Class Codes: G03G 9/08795 characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants
• CPC Class Codes: G03G 9/08797 characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature

Abstract

The present invention provides a crystalline polyester resin having a sharp melt property that realizes both fixing performance and blocking property and demonstrates favorable charging performance, in which the crystalline polyester resin for toner, satisfying the following relationships, 25≦Tg≦70, and (Tg+273)/(Mp+273)≧0.75, wherein Tg (° C.) represents a glass transition temperature of the crystalline polyester resin for toner, and Mp (° C.) represents a melting point of the crystalline polyester resin for toner.

Claims

1. A crystalline polyester resin for toner, satisfying the following relationships:

30≦

R≦

100

25≦

Tg≦

70

(Tg+273)/(Mp+273)≧

0.75, and

R=(I_C20/I_C)×

100,

wherein R (%) represents a ratio of low diffraction angle components of the crystalline polyester resin for toner as calculated based on measurement by wide-angle X-ray diffraction,

Tg (°

C.) represents a glass transition temperature of the crystalline polyester resin for toner,

Mp (°

C.) represents a melting point of the crystalline polyester resin for toner,

I_C20 indicates the total area of crystalline peaks detected within a range of 5≦

2θ

≦

20,

I_C indicates the total area of crystalline peaks detected within a range of 5≦

2θ

≦

60, and

2θ

indicates a diffraction angle (deg).

2. The crystalline polyester resin for toner according to claim 1, wherein a degree of crystallinity of the crystalline polyester resin for toner as measured by wide-angle X-ray diffraction is at least 10%.

3. The crystalline polyester resin for toner according to claim 1, wherein the crystalline polyester resin for toner is obtained by condensation polymerization of a dicarboxylic acid component containing at least one compound selected from the group consisting of terephthalic acid, 2,6-naphthalene dicarboxylic acid and derivatives thereof, and a diol component containing at least one compound selected from the group consisting of 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol and derivatives thereof.

4. The crystalline polyester resin for toner according to claim 3, wherein the diol component contains at least one compound selected from the group consisting of 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol and derivatives thereof in a total amount of at least 50% by mole in the diol component.

5. The crystalline polyester resin for toner according to claim 3, wherein the dicarboxylic acid component contains at least one compound selected from the group consisting of terephthalic acid, 2,6-naphthalene dicarboxylic acid and derivatives thereof in a total amount of at least 50% by mole in the dicarboxylic acid component.

6. The crystalline polyester resin for toner according to claim 1, wherein an amount of heat of fusion of the crystalline polyester resin for toner as measured by a differential scanning calorimeter satisfies

H2/H1≦

0.1

wherein H1 (J/g) represents an amount of heat of fusion after a first temperature rise from 25°

C. to 200°

C. at a ramp rate of 10°

C./min, and H2 (J/g) represents an amount of heat of fusion after a second temperature rise from 25°

C. to 200°

C. at a ramp rate of 10°

C./min carried out after cooling to 25°

C. at a cooling rate of 1°

C./min after the first temperature rise and holding for 24 hours at 25°

C.

7. The crystalline polyester resin for toner according to claim 1, wherein the weight-average molecular weight of the crystalline polyester resin for toner as measured by gel permeation chromatography is from 5,000 to 50,000.

12. The crystalline polyester resin for toner according to claim 1, wherein the melting point of the crystalline polyester resin for toner is not more than 125°

C.

8. A method for producing a toner,

the toner comprising a crystalline polyester resin for toner,

the crystalline polyester resin for toner, satisfying the following relationships:

25≦

Tg≦

70, and

(Tg+273)/(Mp+273)≧

0.75

wherein Tg (°

C.) represents a glass transition temperature of the crystalline polyester resin for toner, and Mp (°

C.) represents a melting point of the crystalline polyester resin for toner, the method comprising;

a resin dissolving step of obtaining a resin composition by dissolving, in an organic solvent, a polyester resin obtained by condensation polymerization of a dicarboxylic acid component containing at least one compound selected from the group consisting of terephthalic acid, 2,6-naphthalene dicarboxylic acid and derivatives thereof, and a diol component containing at least one compound selected from the group consisting of 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol and derivatives thereof;

a granulating step of obtaining a dispersion by dispersing the resulting resin composition in an aqueous medium; and

a solvent removal step of removing the organic solvent from the resulting dispersion.

9. The method for producing the toner according to claim 8, wherein in the granulating step, the temperature of the aqueous medium is held at not less than 60°

C. and not more than 100°

C., and

after the granulating step and before the solvent removal step or during the solvent removal step, the temperature of the aqueous medium is cooled at a cooling rate of at least 1°

C./hr and not more than 50°

C./hr.

10. The method for producing the toner according to claim 8, wherein the aqueous medium contains a monovalent metal salt at not less than 1% by mass and not more than 30% by mass.

11. The method for producing the toner according to claim 8, wherein the organic solvent contains at least an organic solvent A and an organic solvent B,

the organic solvent A is a solvent that causes the polyester resin to precipitate when the polyester resin is dissolved in the organic solvent in the resin dissolving step at a concentration of 70% by mass and allowed to stand for 24 hours at 25°

C., and

the organic solvent B is a solvent that does not cause the polyester resin to precipitate when the polyester resin is dissolved in the organic solvent in the resin dissolving step at a concentration of 70% by mass and allowed to stand for 24 hours at 25°

C.

13. A toner comprising a crystalline polyester resin, wherein the crystalline polyester resin satisfies the following relationships:

30≦

R≦

100

25≦

Tg≦

70

(Tg+273)/(Mp+273)≧

0.75, and

R=(I_C20/I_C)×

100,

wherein R (%) represents a ratio of low diffraction angle components of the crystalline polyester resin for toner as calculated based on measurement by wide-angle X-ray diffraction,

Tg (°

C.) represents a glass transition temperature of the crystalline polyester resin,

Mp (°

C.) represents a melting point of the crystalline polyester resin,

I_C20 indicates the total area of crystalline peaks detected within a range of 5≦

2θ

≦

20,

I_C2 indicates the total area of crystalline peaks detected within a range of 5≦

2θ

≦

60, and

2θ

indicates a diffraction angle (deg).