Polyester resin, method for producing same, and toner

Patent metadata

Field	Value
Publication number	US-9791796-B2
Application number	US-201315106959-A
Country	US
Kind code	B2
Filing date	Dec 24, 2013
Priority date	Dec 24, 2013
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

The present invention relates to a polyester resin which comprises a constituent unit represented by general formula (1), a constituent unit derived from a compound having a bisphenol skeleton and a constituent unit derived from a polyvalent carboxylic acid, and wherein the constituent unit derived from a compound having a bisphenol skeleton is contained in an amount of 20 parts by mole or more per 100 parts by mole of the constituent unit derived from a polyvalent carboxylic acid. The present invention is able to provide a polyester resin which has excellent solubility in a solvent and excellent pulverization properties, and which provides a toner having excellent storage stability.

First claim

The invention claimed is:

1. A polyester resin, comprising:
a structural unit of formula (1);
a structural unit derived from a compound having a bisphenol skeleton; and
a structural unit derived from polycarboxylic acid,
wherein the structural unit derived from a compound having a bisphenol skeleton is contained at 20 molar parts or greater relative to 100 molar parts of the structural unit derived from polycarboxylic acid

2. The polyester resin according to claim 1 , wherein the structural unit derived from a compound having a bisphenol skeleton is derived from bisphenol A propylene oxide adduct.

3. The polyester resin according to claim 1 , wherein the structural unit of formula (1) is contained at 5 to 75 molar parts relative to 100 molar parts of the structural unit derived from polycarboxylic acid.

4. The polyester resin according to claim 1 , comprising a structural unit derived from a monomer having at least three functional groups, wherein the structural unit derived from a monomer having at least three functional groups is contained at 1 to 30 molar parts relative to 100 molar parts of the structural unit derived from polycarboxylic acid.

5. The polyester resin according to claim 4 , wherein the structural unit derived from a monomer having at least three functional groups is derived from trimellitic acid or its anhydride.

6. The polyester resin according to claim 1 , wherein a glass transition temperature (Tg) is set at 45 to 100° C.

7. The polyester resin according to claim 1 , wherein a peak molecular weight (Mp) measured by gel permeation chromatography (GPC) is 500 to 50,000.

8. The polyester resin according to claim 1 , wherein a softening temperature is set at 100 to 160° C.

9. A method for producing the polyester resin according to claim 1 , comprising:
polycondensing a monomer mixture comprising a polyalcohol of formula (2), a compound having a bisphenol skeleton, and polycarboxylic acid,
wherein a content of the compound having a bisphenol skeleton in the monomer mixture is 20 molar parts or greater relative to 100 molar parts of the polycarboxylic acid

10. The method for producing a polyester resin according to claim 9 , wherein the compound having a bisphenol skeleton is bisphenol A propylene oxide adduct.

11. The method for producing a polyester resin according to claim 9 , wherein a content of polyalcohol of formula (2) in the monomer mixture is set at 15 to 75 molar parts relative to 100 molar parts of the polycarboxylic acid.

12. The method for producing a polyester resin according to claim 9 , wherein the monomer mixture comprises a monomer having at least three functional groups, and a content of the monomer having at least three functional groups in the monomer mixture is 1 to 30 molar parts relative to 100 molar parts of the polycarboxylic acid.

13. The method for producing a polyester resin according to claim 9 , wherein the monomer having at least three functional groups is trimellitic acid or its anhydride.

14. The method for producing a polyester resin according to claim 9 , wherein the temperature for polycondensing the monomer mixture is 180 to 280° C.

15. The method for producing a polyester resin according to claim 9 , wherein the monomer mixture comprises a release agent.

16. A toner, comprising the polyester resin according to claim 1 .

Assignees

• Mitsubishi Rayon Co
• Mitsubishi Chem Corp

Inventors

• Ozawa Tadahiro
• Sugiura Masaru
• Ansai Ryuichi
• Sakuma Satoshi

Classifications

• C08G63/668

  derived from polycarboxylic acids and polyhydroxy compounds · CPC title

• C08G63/672

  Dicarboxylic acids and dihydroxy compounds · CPC title

• G03G9/08755 Primary

  Polyesters · CPC title