Toner, developing apparatus, and image-forming apparatus
A toner comprising a toner particle containing a binder resin, a colorant, an amorphous polyester, and a crystalline polyester, wherein the binder resin contains a vinyl resin; the amorphous polyester has a monomer unit derived from a linear aliphatic dicarboxylic acid having 6 to 12 carbons, and a monomer unit derived from a dialcohol; the content of the monomer unit derived from a linear aliphatic dicarboxylic acid having 6 to 12 carbons is 10 to 50 mol % with reference to the total monomer units derived from a carboxylic acid in the amorphous polyester; and in a cross section of the toner particle, the vinyl resin constitutes a matrix and the amorphous polyester constitutes domains, and the crystalline polyester is present in the interior of the domains.
1. A toner comprising a toner particle containing a binder resin, a colorant, an amorphous polyester, and a crystalline polyester,
the binder resin containing a vinyl resin,
the amorphous polyester having
a monomer unit derived from a linear aliphatic dicarboxylic acid having at least 6 and not more than 12 carbons, and
a monomer unit derived from a dialcohol,
the content of the monomer unit derived from the linear aliphatic dicarboxylic acid having at least 6 and not more than 12 carbons being at least 10 mol % and not more than 50 mol % with reference to the total monomer units derived from a carboxylic acid in the amorphous polyester, and
in a cross section of the toner particle observed with a transmission electron microscope,
the vinyl resin constituting a matrix and the amorphous polyester constituting domains, and
the crystalline polyester being present in the interior of the domains.
2. The toner according to claim 1 , wherein the amorphous polyester domains have in their interior a lamellar structure derived from the crystalline polyester.
3. The toner according to claim 1 , wherein the peak molecular weight Mp(P) of the amorphous polyester is at least 8,000 and not more than 13,000, and
the softening point of the amorphous polyester is at least 85° C. and not more than 105° C.
4. The toner according to claim 1 , wherein the amorphous polyester has, in terminal position, a structure derived from at least one selected from the group consisting of aliphatic monocarboxylic acids having a peak value for the number of carbons of at least 25 and not more than 102 and aliphatic monoalcohols having a peak value for the number of carbons of at least 25 and not more than 102.
5. The toner according to claim 1 , wherein the content of the amorphous polyester is at least 5.0 mass parts and not more than 30.0 mass parts per 100 mass parts of the binder resin.
6. The toner according to claim 1 , wherein the main component of the crystalline polyester is a polyester that has, in terminal position, a structure derived from an acid monomer selected from lauric acid, stearic acid, and behenic acid.
7. The toner according to claim 1 , wherein the content of the crystalline polyester is at least 3.0 mass parts and not more than 15.0 mass parts per 100 mass parts of the binder resin.
8. The toner according to claim 1 , wherein, in a cross section of the toner particle observed with a transmission electron microscope, the proportion of the amorphous polyester domains present in a region within 25% of a distance, from the contour of the cross section, between the contour and a center point of the cross section is at least 30 area % and not more than 70 area % with reference to the total area of the amorphous polyester domains.
9. The toner according to claim 1 , wherein, in a cross section of the toner particle observed with a transmission electron microscope, the proportion of the amorphous polyester domains present in a region within 50% of a distance, from the contour of the cross section, between the contour and a center point of the cross section is at least 80 area % and not more than 100 area % with reference to the total area of the amorphous polyester domains.
10. The toner according to claim 1 , wherein, in a cross section of the toner particle observed with a transmission electron microscope, the area of the amorphous polyester domains present within 25% of the distance, from the contour of the cross section, between the contour and the center point of the cross section, is at least 1.05 times the area of the amorphous polyester domains present at 25% to 50% of the distance, from the contour of the cross section, between the contour and the center point of the cross section.
11. The toner according to claim 1 , wherein the number-average diameter of the domains is at least 0.3 μm and not more than 3.0 μm.
12. The toner according to claim 1 , wherein the softening point of the toner is at least 110° C. and not more than 140° C.
13. A developing apparatus comprising:
a toner that develops an electrostatic latent image formed on an image-bearing member; and
a toner-carrying member that carries the toner and transports the toner to the image-bearing member, wherein
the toner is the toner described in claim 1 .
14. An image-forming apparatus comprising:
an image-bearing member;
a charging member that charges the image-bearing member;
a toner that develops an electrostatic latent image formed on the image-bearing member; and
a toner-carrying member that contacts the image-bearing member and transports the toner, the image-forming apparatus recovering, using the toner-carrying member, toner remaining on the image-bearing member after transfer, wherein
the toner is the toner described in claim 1 .