Toner for electrostatic image development, method of producing the same, electrostatic image developer, toner cartridge, process cartridge, and image forming apparatus

1. A toner for electrostatic image development having a binder resin comprising an amorphous polyester resin and a crystalline polyester resin, and a coloring agent, and the binder resin satisfies the following relationship (1):

SP ( L )> SP ( H )> SP ( C )  (1)

wherein

SP(H) is the solubility parameter of the binder resin contained in an elution fraction F (0-10) from the beginning of elution of W 1 until 10% of the elution of W 1 when W 1 is the whole area of an elution curve on a gel permeation chromatograph measured for an acetone-soluble fraction of the toner;

SP(L) is the solubility parameter of the binder resin contained in an elution fraction F (80-100) from 80% to 100% of the elution of W 1 ;

SP(C) is the solubility parameter of the crystalline polyester resin,

the crystalline polyester resin has a weight-average molecular weight of from about 6,000 to about 35,000, and a melting point of from about 60° C. to about 120° C.,

a content of the crystalline polyester resin in the toner is from 15.7 wt % to 33.5 wt % based on a weight of the toner,

the amorphous polyester resin comprises an amorphous polyester resin (1) having a weight-average molecular weight of from 8,000 to 25,000 and an amorphous polyester resin (2) having a weight-average molecular weight of from 30,000 to 200,000,

the solubility parameter of the amorphous polyester resin (1) is larger than the solubility parameter of the amorphous polyester resin (2), and

the toner is produced by an emulsification aggregation method.

2. The toner for electrostatic image development of claim 1 , wherein the elution fraction F (0-10) comprises a component containing at least one of alkenylsuccinic acid and anhydrides thereof and at least one of trimellitic acid and anhydrides thereof reacted therein.

3. The toner for electrostatic image development of claim 1 , which satisfies the following relationship (2):

0 ≦B<A   (2)

wherein A and B are the content (weight percentage), in the elution fractions F (0-10) and F (80-100) respectively, of a component containing at least one of alkenylsuccinic acid and anhydrides thereof reacted therein.

4. The toner for electrostatic image development of claim 1 , wherein the crystalline polyester resin is an aliphatic crystalline polyester resin obtained by reacting a dicarboxylic acid having a carbon number of 10-12 with a diol having a carbon number of 4-9.

5. The toner for electrostatic image development of claim 4 , wherein the content of the diol-derived component of the crystalline polyester resin is about 80 mol % or more.

6. The toner for electrostatic image development of claim 4 , wherein the constituent ratio of an aliphatic polymerizable monomer included in the aliphatic crystalline polyester resin is about 60 mol % or more,

wherein the constituent is an aliphatic diol or aliphatic dicarboxylic acid.

7. The toner for electrostatic image development of claim 1 , wherein the toner comprises a release agent having a melting point of from about 50° C. to about 100° C.

8. The toner for electrostatic image development of claim 1 , wherein the toner has a shape factor SF 1 in the range of about 110 to about 140.

9. The toner for electrostatic image development of claim 1 , wherein the toner comprises two or more external additives, and at least one of the external additives has a number-average primary particle diameter in the range of about 30 to about 200 nm.

10. An electrostatic image developer comprising the toner for electrostatic image development of claim 1 .

11. The electrostatic image developer of claim 10 , wherein the toner is mixed with resin coated carriers.

12. The electrostatic image developer of claim 10 , wherein the toner is mixed with a resin dispersion carrier in which an electrically conductive material is dispersed in a matrix resin.

13. The toner for electrostatic image development of claim 1 , wherein the amorphous polyester resin (1) and the amorphous polyester resin (2) are a combination of two resins selected from the group consisting of: resin (1) and resin (2); resin (3) and resin (4); resin (5) and resin (4); and resin (5) and resin (2),

wherein

resin (1) is the amorphous polyester resin (2), has a weight-average molecular weight of 45,000, and is included in a reaction product of 40 mol % of dimethyl terephthalate, 20 mol % of dimethyl fumarate, 35 mol % of dedecenyl succinic acid anhydride, 5 mol % of trimellitic acid anhydride, 10 mol % of bisphenol A-ethylene oxide, and 90 mol % of bisphenol A-propylene oxide,

resin (2) is the amorphous polyester resin (1), has a weight average molecular weight of 14,000, and is included in a reaction product of 70 mol % of dimethyl terephthalate, 10 mol % of dimethyl fumarate, 25 mol % of dedecenyl succinic acid anhydride, 10 mol % of bisphenol A-ethylene oxide, and 90 mol % of bisphenol A-propylene oxide,

resin (3) is the amorphous polyester resin (2), has a weight-average molecular weight of 38,000, and is included in a reaction product of 20 mol % of dimethyl terephthalate, 55 mol % of dimethyl fumarate, 25 mol % of dedecenyl succinic acid anhydride, 15 mol % of bisphenol A-ethylene oxide, and 85 mol % of bisphenol A-propylene oxide,

resin (4) is the amorphous polyester resin (1), has a weight-average molecular weight of 12,000, and is included in a reaction product of 65 mol % of dimethyl terephthalate, 15 mol % of dimethyl fumarate, 20 mol % of dedecenyl succinic acid anhydride, 30 mol % of bisphenol A-ethylene oxide, and 70 mol % of bisphenol A-propylene oxide, and

resin (5) is the amorphous polyester resin (2), has a weight-average molecular weight of 42,000, and is included in a reaction product of 25 mol % of dimethyl terephthalate, 50 mol % of dimethyl fumarate, 20 mol % of dedecenyl succinic acid anhydride, 5 mol % of trimellitic acid anhydride, 10 mol % of bisphenol A-ethylene oxide, and 90 mol % of bisphenol A-propylene oxide.