Electrostatic-image-developing toner, process for producing electrostatic-image-developing toner, electrostatic image developer, image-forming method, and image-forming apparatus
View Patent ↗An electrostatic-image-developing toner is obtained by aggregating: resin particles, each of which has a core-shell structure, in which a difference in glass transition temperature between a resin constituting the core and a resin constituting the shell is about 20° C. or more; and releasing agent particles, each of which includes a polyester block copolymer having a weight-average molecular weight of about 3,000 or less and containing a non-crystalline polyester block containing a cyclic structure in the main chain and a crystalline polyester block containing no cyclic structure in the main chain.
1. An electrostatic-image-developing toner obtained by aggregating:
resin particles, each of which has a core-shell structure, in which a difference in glass transition temperature between a resin constituting the core and a resin constituting the shell is about 20° C. or more; and
releasing agent particles, each of which comprises a polyester block copolymer having a weight-average molecular weight of about 3,000 or less and containing a non-crystalline polyester block containing a cyclic structure in a main chain and a crystalline polyester block containing no cyclic structure in the main chain.
2. The electrostatic-image-developing toner according to claim 1 , wherein
at least either the resin constituting the core or the resin constituting the shell contains a non-crystalline addition polymerization type resin.
3. The electrostatic-image-developing toner according to claim 1 , wherein
the resin constituting the shell has an acidic or basic polar group or an alcoholic hydroxyl group.
4. The electrostatic-image-developing toner according to claim 3 , wherein
the acidic polar group is any one of a carboxyl group, a sulfonic acid group, and an acid anhydride.
5. The electrostatic-image-developing toner according to claim 3 , wherein
the basic polar group is any one of an amino group, an amido group, and a hydrazide group.
6. The electrostatic-image-developing toner according to claim 5 , wherein
a monomer for forming the basic polar group is a (meth)acrylic acid amide compound, a (meth)acrylic acid hydrazide compound, or an aminoalkyl (meth)acrylate compound.
7. The electrostatic-image-developing toner according to claim 3 , wherein
a monomer for forming the alcoholic hydroxyl group is a hydroxy acrylate.
8. The electrostatic-image-developing toner according to claim 1 , wherein
the glass transition temperature of the resin constituting the shell is higher than the glass transition temperature of the resin constituting the core.
9. The electrostatic-image-developing toner according to claim 8 , wherein
about 80% by weight of monomer units constituting the resin constituting the core are a (meth)acrylic acid ester.
10. The electrostatic-image-developing toner according to claim 1 , wherein
the resin constituting the core has a weight-average molecular weight of from about 3,000 to about 50,000.
11. The electrostatic-image-developing toner according to claim 1 , wherein
the resin constituting the shell has a weight-average molecular weight of from about 3,000 to about 50,000.
12. The electrostatic-image-developing toner according to claim 1 , wherein
a weight ratio of the resin constituting the core to the resin constituting the shell is from about 10:90 to about 90:10.
13. The electrostatic-image-developing toner according to claim 1 , wherein
a weight ratio of the non-crystalline polyester block to the crystalline polyester block is from about 1:20 to about 20:1.
14. The electrostatic-image-developing toner according to claim 1 , wherein
a crystalline polyester resin for forming the crystalline polyester block has a crystal melting temperature of from about 40° C. to about 150° C.
15. An electrostatic image developer comprising:
the electrostatic-image-developing toner described in claim 1 ; and
a carrier.