Toner production method and polymer
A toner production method including: a melt-kneading step of melt-kneading a resin composition including a binder resin, a colorant, a wax, and a wax dispersant to obtain a melt-kneaded product; and a pulverizing step of pulverizing the melt-kneaded product. Where the temperature of the melt-kneaded product at the end of the melt-kneading step is Tk (° C.), and the softening point of the wax dispersant is Tm (° C.), the relationship of −18≤[Tk−Tm]≤10 is satisfied. The wax dispersant is a polymer in which a styrene acrylic polymer is graft-polymerized to a polyolefin. The styrene acrylic polymer has a monomer unit derived from α-methylstyrene and a monomer unit derived from a cycloalkyl (meth)acrylate.
1. A toner production method comprising:
a melt-kneading step of melt-kneading a resin composition including a binder resin, a colorant, a wax, and a wax dispersant to obtain a melt-kneaded product; and
a pulverizing step of pulverizing the melt-kneaded product, wherein
−18≤[Tk−Tm]≤10 where a temperature of the melt-kneaded product at an end of the melt-kneading step is Tk (° C.), and a softening point of the wax dispersant is Tm (° C.),
the wax dispersant is a polymer in which a styrene acrylic polymer is grafted to a polyolefin,
the styrene acrylic polymer has a monomer unit derived from α-methylstyrene and a monomer unit derived from a cycloalkyl (meth)acrylate,
the monomer unit derived from the cycloalkyl (meth)acrylate is represented by formula (2)
where R 1 represents a hydrogen atom or a methyl group, and R 2 represents a cycloalkyl group, and
the monomer unit derived from α-methylstyrene is represented by formula (4)
2. The toner production method according to claim 1 , wherein an amount of the monomer unit derived from α-methylstyrene in the polymer is 5.0 to 30.0% by mass.
3. The toner production method according to claim 1 , wherein the softening point of the wax dispersant is 100.0 to 130.0° C.
4. The toner production method according to claim 1 , wherein the styrene acrylic polymer further has a monomer unit represented by formula (3)
where R 3 represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 18.
5. The toner production method according to claim 1 , wherein the monomer unit derived from the cycloalkyl (meth)acrylate is derived from cyclohexyl methacrylate.
6. The toner production method according to claim 1 , wherein the polyolefin is polypropylene having a melting point of 70 to 90° C.
7. The toner production method according to claim 1 , wherein the amount of the polymer is 1.0 to 10.0 parts by mass with respect to 100 parts by mass of the binder resin.