RESIN FOR TONER AND TONER

• US 20150099227A1
• Filed: 12/15/2014
• Published: 04/09/2015
• Est. Priority Date: 04/09/2013
• Status: Abandoned Application

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Ida, Hayato, Hirasa, Takashi, Tamura, Junichi, Chimoto, Yuya, Shibata, Takaho, Yamashita, Daisuke
• Application Number:
  US14/571,159
• Publication Number:
  US 20150099227A1
• Time in Patent Office: Days
• US Class Current: 430/137.15
• 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 63/16 Dicarboxylic acids and dihydroxy compounds
• CPC Class Codes: C08G 63/181 Acids containing aromatic rings
• CPC Class Codes: C08G 63/183 Terephthalic acids
• CPC Class Codes: C08G 64/183 containing polyether sequences
• 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 for toner that has, when used as a resin for toner, a sharp melt property, excellent fixing performance and blocking property and a preferable charging performance. Provided is a crystalline polyester resin for toner, which 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-naphthalenedicarboxylic 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, the crystalline polyester resin having a weight-average molecular weight of not less than 5000 and not more than 50000.

Claims

1. A crystalline polyester resin for toner, which 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-naphthalenedicarboxylic acid and derivatives thereof, and

a diol component containing at least one compound selected from the group consisting of 2-methyl-1,3-propanediol and derivatives thereof, wherein

the dicarboxylic acid component contains terephthalic acid, 2,6-naphthalenedicarboxylic acid and derivatives thereof in total at not less than 50% by mole based on a sum of the dicarboxylic acid component,

the diol component contains 2-methyl-1,3-propanediol and derivatives thereof in total at not less than 50% by mole based on a sum of the diol component, and

the crystalline polyester resin has a weight-average molecular weight as measured by gel permeation chromatography of not less than 5000 and not more than 50000.

4. The crystalline polyester resin for toner according to claim 1, which has a degree of crystallinity as measured by wide-angle X-ray diffraction of not less than 10%.

5. The crystalline polyester resin for toner according to claim 1, which has a glass transition temperature of not less than 25°

C. and not more than 70°

C.

6. The crystalline polyester resin for toner according to claim 1, which has a melting point of not more than 125°

C.

7. The crystalline polyester resin for toner according to claim 1, wherein an amount of heat of fusion as measured by a differential scanning calorimeter fulfills the following formula (1):

H2/H1≦

0.1 

 

Formula (1);

wherein H1 (J/g) is an amount of heat of fusion during a first heating from 25°

C. to 200°

C. with a ramp rate of 10°

C./min, and H2 (J/g) is an amount of heat of fusion during a second heating, after cooling to 25°

C. with a cooling rate of 1°

C./min after the first heating and maintenance at 25°

C. for 24 hours, from 25°

C. to 200°

C. with a ramp rate of 10°

C./min.

8. Toner comprising the crystalline polyester resin for toner according to claim 1.

9. A method for producing the toner according to claim 8, comprising:

a resin dissolution step of dissolving a polyester resin in an organic solvent to obtain a resin composition,

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

a solvent removal step of removing the organic solvent from the resulting dispersion, wherein,

the polyester resin 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-naphthalenedicarboxylic acid and derivatives thereof, and

a diol component containing at least one compound selected from the group consisting of 2-methyl-1,3-propanediol and derivatives thereof, and wherein

the dicarboxylic acid component contains terephthalic acid, 2,6-naphthalenedicarboxylic acid and derivatives thereof in total at not less than 50% by mole based on a sum of the dicarboxylic acid component,

the diol component contains 2-methyl-1,3-propanediol and derivatives thereof in total at not less than 50% by mole based on a sum of the diol component, and

the polyester resin has a weight-average molecular weight as measured by gel permeation chromatography of not less than 5000 and not more than 50000.

10. The method according to claim 9, wherein:

in the granulating step, a temperature of the aqueous medium is maintained at 60°

C. to 100°

C. and

after the granulating step and before the solvent removal step or in the solvent removal step, the aqueous medium is cooled with a cooling rate of 1°

C./hr to 50°

C./hr.

11. The method according to claim 9, wherein the aqueous medium contains a monovalent metal salt at not less than 1% by mass and not more than 30% by mass.

12. The method according to claim 9, wherein:

the organic solvent contains at least an organic solvent A and an organic solvent B;

the organic solvent A is such that, when the polyester resin to be dissolved in the organic solvent in the resin dissolution step is dissolved at a concentration of 70% by mass in the organic solvent A and allowed to stand at 25°

C. for 24 hours, the polyester resin is precipitated; and

the organic solvent B is such that, when the polyester resin to be dissolved in the organic solvent in the resin dissolution step is dissolved at a concentration of 70% by mass in the organic solvent B and allowed to stand at 25°

C. for 24 hours, the polyester resin is not precipitated.

2-3. -3. (canceled)