# US 5,346,792 A · Color toner

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- Number: US 5,346,792 A
- Document ID: US5346792A
- Status: Granted
- Kind: A
- Application number: 07/895,046
- Filed: 1992-06-08
- Granted: 1994-09-13
- Earliest claimed: 1991-06-11
- Assignees: Canon Kabushiki Kaisha
- Inventors: Hiroyuki Kobayashi; Takaaki Kohtaki
- Web page: https://patentgrep.com/patent/US5346792A

## CPC

- G03G 9/08755: {Polyesters}
- Y10S 430/105: Polymer in developer
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

A color toner is constituted to form a polyester binder resin and a colorant. The polyester resin is obtained from a monomer mixture including, at least: 25-35 mol. % of a dibasic aromatic acid component (a) selected from isophthalic acid, terephthalic acid and derivatives thereof; 2-4 mol. % of a tribasic aromatic acid component (b) selected from trimellitic acid and derivatives thereof; 12-18 mol. % of a dibasic acid component (c) selected from dodecenylsuccinic acid, octylsuccinic acid, and anhydrides thereof; and 45-60 mol. % of an etherified diphenol component (d) obtained by propoxidation or/and epoxidation, each percentage being based on a total of the monomers. The polyester resin is characterized by having a hydroxyl value of 10-20, a weight-average molecular weight (Mw) of 13,000-20,000, a number-average molecular weight (Mn) of 5,000-8,000, and an Mw/Mn ratio of 2-3.5.

## Claims

### Claim 1

A color toner, comprising: a binder resin and a colorant; the binder resin comprising a polyester resin obtained from a monomer mixture including, at least:
25-35 mol. % of a dibasic aromatic acid component (a) selected from the group consisting of isophthalic acid, terephthalic acid and derivatives thereof,
2-4 mol. % of a tribasic aromatic acid component (b) selected from the group consisting of trimellitic acid and derivatives thereof,
12-18 mol. % of a dibasic acid component (c) selected from the group consisting of dodecenylsuccinic acid, octylsuccinic acid, and anhydrides thereof, and
45-60 mol. % of an etherified diphenol component (d) obtained by propoxidation or/and epoxidation, each percentage being based on a total of the monomers,
wherein the polyester resin has a hydroxyl value of 10-20, a weight-average molecular weight (Mw) of 13,000-20,000, a number-average molecular weight (Mn) of 5,000-8,000, and a weight-average molecular weight/number-average molecular weight (Mw/Mn) ratio of 2-3.5.

### Claim 2 (depends on 1)

The color toner according to claim 1, wherein the binder resin comprises a crosslinked polyester resin having an Mw/Mn ratio of 2.0-3.0.

### Claim 3 (depends on 1)

The color toner according to claim 1, wherein the binder resin comprises a crosslinked polyester resin obtained from terephthalic acid, trimellitic acid or trimellitic anhydride, dodecenylsuccinic acid or dodecenylsuccinic anhydride, and polyoxypropylene-2,2-bis(4-hydroxyphenyl)propane or polyoxyethylene-2,2-bis(4-hydroxyphenyl)propane.

### Claim 4 (depends on 1)

The color toner according to claim 1, wherein the binder resin comprises a crosslinked polyester resin obtained from isophthalic acid, trimellitic acid or trimellitic anhydride, octylsuccinic acid or octylsuccinic anhydride, and polyoxypropylene-2,2-bis(4-hydroxyphenyl)propane or polyoxyethylene-2,2-bis(4-hydroxyphenyl)propane.

### Claim 5 (depends on 1)

The color toner according to claim 1, wherein the polyester resin has a glass transition point of 55.degree.-60.degree. C., a hydroxyl value of 12-18, a weight-average molecular weight (Mw) of 14,000-19,000, a number-average molecular weight (Mn) of 5,300-7,500, and an Mw/Mn ratio of 2.0-3.0.

### Claim 6 (depends on 1)

The color toner according to claim 1, wherein the colorant comprises a yellow colorant.

### Claim 7 (depends on 6)

The color toner according to claim 6, wherein the yellow colorant is contained in a proportion of 0.5-7 wt. parts per 100 wt. parts of the binder resin.

### Claim 8 (depends on 1)

The color toner according to claim 1, wherein the colorant comprises a magenta colorant.

### Claim 9 (depends on 8)

The color toner according to claim 8, wherein the magenta colorant is contained in a proportion of 0.1-9 wt. parts per 100 wt. parts of the binder resin.

### Claim 10 (depends on 1)

The color toner according to claim 1, wherein the colorant comprises a cyan colorant.

### Claim 11 (depends on 10)

The color toner according to claim 10, wherein the cyan colorant is contained in a proportion of 0.1-9 wt. parts per 100 wt. parts of the binder resin.

### Claim 12 (depends on 1)

The color toner according to claim 1, further comprising a charge control agent.

### Claim 13 (depends on 12)

The color toner according to claim 12, wherein the charge control agent is a compound selected from the group consisting of salicylic acid metal complexes, alkylsalicylic acid metal complexes, dialkylsalicylic acid metal complexes, and oxynaphthoic acid metal complexes.

### Claim 14 (depends on 12)

The color toner according to claim 12, wherein the charge control agent comprises dialkylsalicylic acid chromium complex.

### Claim 15 (depends on 12)

The color toner according to claim 12, wherein the charge control agent comprises dialkylsalicylic acid zinc complex.

### Claim 16 (depends on 1)

The color toner according to claim 1, which is in mixture with hydrophobic colloidal silica fine powder.

### Claim 17 (depends on 1)

The color toner according to claim 1, which is in mixture with hydrophobic titanium oxide fine powder.