Toner and toner producing method, and developer

Patent metadata

Field	Value
Publication number	US-2016147167-A1
Application number	US-201414899425-A
Country	US
Kind code	A1
Filing date	Jun 5, 2014
Priority date	Jun 19, 2013
Publication date	May 26, 2016
Grant date	—

Abstract

Provided is a toner obtained by granulating a toner composition in a hydrophobic medium and then drying the granulated product. The toner contains a binder resin. The binder resin includes 2 or more kinds of binder resins having different contact angles (to water). The binder resin having the largest contact angle has a weight average molecular weight of 15,000 or less. The other binder resins have a weight average molecular weight of greater than 15,000.

First claim

1 . A toner, comprising:
a binder resin, wherein the toner is obtained by granulating a toner composition in a hydrophobic medium, and then drying a granulated product, wherein the binder resin comprises 2 or more kinds of binder resins having different contact angles to water, wherein the binder resin having a largest contact angle has a weight average molecular weight of 15,000 or less, and wherein the other binder resins have a weight average molecular weight of greater than 15,000.

2 . The toner according to claim 1 ,
wherein a contact angle (CAa) of the toner before hot-melting and a contact angle (CAb) of the toner after hot-melting satisfy a formula (I):
CA b +3°≦CA a   (Formula I).

3 . The toner according to claim 1 ,
wherein the binder resin having the largest contact angle has a glass transition point (Tg) of 50° C. or higher.

4 . The toner according to claim 1 ,
wherein a ratio of the binder resin having the largest contact angle to the binder resins is from 5% by mass to 50% by mass.

5 . The toner according to claim 1 ,
wherein a difference between the contact angle of the binder resin having the largest contact angle and the contact angles of the other binder resins is 5° or more.

6 . The toner according to claim 1 ,
wherein the toner has a volume average particle diameter of from 1 μm to 10 μm, and a particle size distribution, which is volume average particle diameter/number average particle diameter, of from 1.00 to 1.10.

7 . A method of producing toner, comprising:
discharging a toner composition liquid from a discharge hole to form liquid droplets; and solidifying the liquid droplets, wherein the toner composition liquid comprises a binder resin and a releasing agent, wherein the binder resin comprises 2 or more kinds of binder resins having different contact angles to water, and wherein the binder resin having a largest contact angle has a weight average molecular weight of 15,000 or less.

8 . The method according to claim 7 ,
wherein the discharging a toner composition liquid comprises forming the liquid droplets by applying a vibration to the toner composition liquid in a liquid column resonance liquid chamber that is provided with at least one discharge hole to form a standing wave based on a liquid column resonance and discharge the toner composition liquid from the discharge hole formed in a region corresponding to an anti-node of the standing wave.

9 . The method according to claim 7 ,
wherein the discharging a toner composition liquid comprises forming the liquid droplets by applying with a vibration unit, a vibration to a thin film in which a plurality of discharge holes having a same opening size are formed, to discharge the toner composition liquid from the discharge holes.

10 . A developer, comprising:
a toner; and a carrier, wherein the toner is obtained by granulating a toner composition in a hydrophobic medium, and then drying a granulated product, wherein the binder resin comprises 2 or more kinds of binder resins having different contact angles to water, wherein the binder resin having a largest contact angle has a weight average molecular weight of 15,000 or less, and wherein the other binder resins have a weight average molecular weight of greater than 15,000.

11 . The developer according to claim 10 ,
wherein a contact angle (CAa) of the toner before hot-melting and a contact angle (CAb) of the toner after hot-melting satisfy a formula (I):
CA b +3°≦CA a   (Formula I).

12 . The developer according to claim 10 , wherein the binder resin having the largest contact angle has a glass transition point (Tg) of 50° C. or higher.

13 . The developer according to claim 10 , wherein a ratio of the binder resin having the largest contact angle to the binder resins is from 5% by mass to 50% by mass.

14 . The developer according to claim 10 , wherein a difference between the contact angle of the binder resin having the largest contact angle and the contact angles of the other binder resins is 5° or more.

15 . The developer according to claim 10 , wherein the toner has a volume average particle diameter of from 1 μm to 10 μm, and a particle size distribution, which is volume average particle diameter/number average particle diameter, of from 1.00 to 1.10.

Assignees

• Ricoh Co Ltd

Inventors

• Moritani Tatsuru
• Moriya Yoshihiro
• Inoue Ryota
• Yamaguchi Tatsuki

Classifications

• G03G9/08795

  characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants · CPC title

• G03G9/0802

  Preparation methods · CPC title

• G03G9/08797 Primary

  characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature · CPC title

• G03G9/0819

  characterised by the dimensions of the particles · CPC title

• G03G9/0825

  characterised by their structure; characterised by non-homogenuous distribution of components (microcapsular toners G03G9/093) · CPC title