Resin composition for toner, toner, developer and image forming apparatus
A resin composition for a toner including a polyester resin and a colorant, wherein the polyester resin has A(10)-A(180) of 70 or greater, where A(10) (%) is a transmittance of light having a wavelength of 500 nm through a mixture of 20 parts by mass of the polyester resin added to 80 parts by mass of ethyl acetate and stirred at 25° C. for 10 minutes, and A(180) (%) is the transmittance after the mixture is left to stand for 3 hours.
1. A resin composition, comprising:
a polyester resin prepared from monomers comprising an aliphatic alcohol and an aromatic carboxylic acid; and
a colorant,
wherein the aliphatic alcohol comprises propylene glycol and 1,3-propanediol, where a molar ratio of propylene glycol with respect to a total of propylene glycol and 1,3-propanediol is from 65% to 85%,
the aromatic carboxylic acid comprises terephthalic acid, and
the polyester resin has a A(10)-A(180) value of 70 or greater, where A(10) (%) is a transmittance of light having a wavelength of 500 nm through a mixture obtained by adding 20 parts by mass of the polyester resin to 80 parts by mass of ethyl acetate and stirring at 25° C. for 10 minutes, and A(180) (%) is the transmittance after the mixture is left to stand for 3 hours.
2. The resin composition according to claim 1 , wherein A(10) is 90 or greater, and A(180) is 10 or less.
3. The resin composition according to claim 1 , wherein the polyester resin has a glass transition temperature of 55° C. or greater.
4. The resin composition according to claim 1 ,
wherein
the aromatic carboxylic acid further comprises isophthalic acid.
5. The resin composition according to claim 1 , wherein the polyester resin has a glass transition temperature of 64° C. or greater.
6. The resin composition according to claim 1 , wherein the polyester resin has a glass transition temperature of 66° C. or greater.
7. The resin composition according to claim 1 , wherein A(10) is 95 or greater.
8. A toner, comprising:
a first polyester resin prepared from monomers comprising an aliphatic alcohol and an aromatic carboxylic acid; and
a colorant,
wherein the aliphatic alcohol comprises propylene glycol and 1,3-propanediol, where a molar ratio of propylene glycol with respect to a total of propylene glycol and 1,3-propanediol is from 65% to 85%,
the aromatic carboxylic acid comprises terephthalic acid, and
the first polyester resin has a A(10)-A(180) value of 70 or greater, where A(10) (%) is a transmittance of light having a wavelength of 500 nm through a mixture obtained by adding 20 parts by mass of the first polyester resin to 80 parts by mass of ethyl acetate and stirring at 25° C. for 10 minutes, and A(180) (%) is the transmittance after the mixture is left to stand for 3 hours.
9. The toner according to claim 8 , further comprising:
a second polyester resin,
wherein the second polyester resin has A(10) of 90 or greater and A(180) of 90 or greater, where A(10) (%) is a transmittance of light having a wavelength of 500 nm through a mixture obtained by adding 20 parts by mass of the second polyester resin to 80 parts by mass of ethyl acetate and stirring at 25° C. for 10 minutes, and A(180) (%) is the transmittance after the mixture is left to stand for 3 hours.
10. The toner according to claim 9 ,
wherein a content by mass of the first polyester resin to a content by mass of the second polyester resin is in a range of 5/95 to 70/30.
11. The toner according to claim 8 , further comprising:
a crystalline resin.
12. The toner according to claim 11 ,
wherein a content of the crystalline resin with respect to a total amount of the resins in the toner is 50% by mass or greater.
13. The toner according to claim 11 ,
wherein the crystalline resin comprises a crystalline polyester resin.
14. A developer, comprising:
the toner according to claim 8 ; and
a carrier.
15. The toner according to claim 8 ,
wherein
the aromatic carboxylic acid further comprises isophthalic acid.
16. The toner according to claim 8 , wherein A(10) is 90 or greater, and A(180) is 10 or less.
17. The toner according to claim 8 , wherein the first polyester resin has a glass transition temperature of 55° C. or greater.
18. The toner according to claim 8 , wherein the first polyester resin has a glass transition temperature of 64° C. or greater.
19. The toner according to claim 8 , wherein the first polyester resin has a glass transition temperature of 66° C. or greater.
20. The toner according to claim 8 , wherein A(10) is 95 or greater.