Toner, developer, image forming apparatus and toner housing unit
A toner fixable on an image bearer with heat. The toner has a first storage modulus of from 1×10 3 to 1×10 6 Pa, measured at 100° C. when being heated, and a second storage modulus of from 1×10 3 to 1×10 6 Pa, measured at 100° C. when being cooled, the first storage modulus and second storage modulus being measured by a rheometer, and the second storage modulus at 100° C. when being cooled is higher than the first storage modulus at 100° C. when being heated.
1. A toner fixable on an image bearer with heat, comprising a binder resin and a salicylic acid metal salt derivative,
wherein the toner has a first storage modulus of from 1×10 3 to 1×10 6 Pa, measured at 100° C. when being heated, and a second storage modulus of from 1×10 3 to 1×10 6 Pa, measured at 100° C. when being cooled, the first storage modulus and second storage modulus being measured by a rheometer, and
wherein the second storage modulus at 100° C. when being cooled is higher than the first storage modulus at 100° C. when being heated.
2. The toner of claim 1 , wherein the first storage modulus is from 1×10 4 to 1×10 5 Pa, measured at 100° C. when being heated, and the second storage modulus is from 1×10 4 to 1×10 5 Pa, measured at 100° C. when being cooled.
3. The toner of claim 1 , wherein a rate of change R M (%) determined from the following formula (1) is from 10% to 140%:
R M =( Mw 2− Mw 1)/ Mw 1×100 (1)
wherein Mw1 represents a weight-average molecular weight of the toner before heated; and Mw2 represents a weight-average molecular weight of the toner after heated.
4. The toner of claim 3 , wherein the rate of change R M (%) is from 30% to 80%.
5. The toner of claim 1 , comprising a crystalline polyester resin.
6. The toner of claim 1 , comprising a binder resin, wherein the binder resin includes:
a polyester resin having an acid value; and
a member selected from the group consisting of a metal complex or salt of a salicylic acid having the following formula (2) and a metal complex or salt of a hydroxyl naphthoic acid derivative:
wherein R 1 , R 2 , R 3 and R 4 independently represent a member selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 1 to 12 carbon atoms, —OH, —NH 2 , —NH(CH 3 ), —N(CH 3 ) 2 , —OCH 3 , —O(C 2 H 5 ), —COOH and —CONH 2 ; and the metal salt is a member selected from the group consisting of Zn 2+ , Al 3+ , Cr 3+ , Fe 3+ or Zr 4+ .
7. The toner of claim 1 , wherein a rate of change R AV (%) determined from the following formula (3) is from 20% to 80%:
R AV =( Av 2− Av 1)/ Av 1×100 (3)
wherein Av1 represents an acid value of the toner before heated; and Av2 represents an acid value of thereof after heated.
8. A method of producing the toner according to claim 1 , comprising:
dissolving or dispersing at least a binder resin in an organic solvent to prepare a solution or a first dispersion;
dispersing or emulsifying the solution or the dispersion in an aqueous medium to prepare an emulsion or a second dispersion; and
removing the organic solvent from the emulsion or the dispersion.
9. A toner housing unit housing the toner according to claim 1 .
10. An image forming apparatus, comprising:
a photoconductor;
a charger to charge the photoconductor;
an irradiator to irradiate the photoconductor to form an electrostatic latent image on the photoconductor;
an image developer to develop the electrostatic latent image with the toner according to claim 1 to form a toner image on the photoconductor;
a transferer to transfer the toner image onto a recording medium; and
a fixer to fix the toner image on the recording medium.
11. An image forming method, comprising:
forming an electrostatic latent image on a photoconductor;
developing the electrostatic latent image with the toner according to claim 1 to form a toner image on the photoconductor;
transferring the toner image onto a recording medium; and
fixing the toner image on the recording medium.
12. The toner of claim 1 , further comprising a crystalline polyester resin and wherein the binder resin includes:
a polyester resin having an acid value; and
a member selected from the group consisting of a metal complex or salt of a salicylic acid having the following formula (2) and a metal complex or salt of a hydroxyl naphthoic acid derivative:
wherein R 1 , R 2 , R 3 and R 4 independently represent a member selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 1 to 12 carbon atoms, —OH, —NH 2 , —NH(CH 3 ), —N(CH 3 ) 2 , —OCH 3 , —O(C 2 H 5 ), —COOH and —CONH 2 ; and the metal salt is a member selected from the group consisting of Zn 2+ , Al 3+ , Cr 3+ , Fe 3+ or Zr 4+ .