Toner, developer, and image forming device

1. A toner comprising:

a polyester resin,

wherein the toner has a glass transition temperature (Tg1 st) at first temperature rising of differential scanning calorimetry (DSC) of from 45° C. to 65° C.,

wherein the toner includes a component insoluble in tetrahydrofuran (THF) having two glass transition temperatures (Tga1st and Tgb1st) at the first temperature rising of DSC, Tga1st being in a range of −45° C. to 5° C., and Tgb1st being in a range of 45° C. to 70° C., and

wherein the toner includes a component soluble in THF having a glass transition temperature (Tg2nd) at second temperature rising of DSC of from 40° C. to 65° C.

2. The toner according to claim 1 ,

wherein the component insoluble in THF has a glass transition temperature (Tg2nd′) at the second temperature rising of DSC of from 0° C. to 50° C.

3. The toner according to claim 1 ,

wherein the glass transition temperature (Tg1st) and a glass transition temperature (Tg2nd) of the toner at the first temperature rising and the second temperature rising, respectively, of DSC satisfy the following formula:

Tg 1 st−Tg 2 nd≥ 10 [° C.].

4. The toner according to claim 1 ,

wherein the component insoluble in THF includes:

a polyester resin component A having a glass transition temperature (Tg2nd) at the second temperature rising of DSC of from −50° C. to 0° C.; and

a polyester resin component B having a glass transition temperature (Tg2nd) at the second temperature rising of DSC of from 45° C. to 65° C., and

wherein the component soluble in THF includes:

a polyester resin component C having a glass transition temperature (Tg2nd) at the second temperature rising of DSC of from 40° C. to 65° C.

5. The toner according to claim 4 ,

wherein the following formula is satisfied:

4( a+b )< c

where a, b, and c respectively represent mass ratios of the polyester resin component A, the polyester resin component B, and the polyester resin component C, with respect to a total mass of the polyester resin component A, the polyester resin component B, and the polyester resin component C.

6. The toner according to claim 4 ,

wherein the polyester resin component A contains a trivalent or tetravalent aliphatic polyvalent alcohol component having 3 to 10 carbon atoms.

7. The toner according to claim 4 ,

wherein the polyester resin component A contains a diol component, and

wherein the diol component has a main chain having carbon atoms in an odd number of from 3 to 9 and an alkyl group on a side chain.

8. The toner according to claim 4 ,

wherein the polyester resin component A has at least one of a urethane bond and a urea bond.

9. The toner according to claim 4 ,

wherein the polyester resin component B has at least one of a urethane bond and a urea bond.

10. The toner according to claim 4 ,

wherein the polyester resin component C contains a trivalent or tetravalent aliphatic polyvalent alcohol component having 3 to 10 carbon atoms.

11. A developer comprising:

the toner according to claim 1 ; and

a carrier.

12. An image forming device comprising:

an electrostatic latent image bearer;

an electrostatic latent image forming unit configured to form an electrostatic latent image on the electrostatic latent image bearer; and

a developing unit including the toner according to claim 1 , the developing unit configured to develop the electrostatic latent image on the electrostatic latent image bearer into a toner image with the toner.

13. The image forming device according to claim 12 ,

wherein the electrostatic latent image bearer has a linear velocity of greater than or equal to 300 mm/s.