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US 5,747,210 AGranted
Electrostatic image developing toner and method for producing the toner
AssigneeRicoh Company, Ltd.
InventorsShigeru Emoto, Kumi Hasegawa, Youichi Maekawa, Kazuhito Watanabe, Kouki Katoh
Life of this patent
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Abstract
An electrostatic image developing toner containing a polyester binder resin in which an oxyalkylether of a novolak phenol resin is crosslinked with polycarboxyl groups and contains 5 to 20% by weight of components having a weight-average molecular weight greater than about 1.times.10.sup.7 and is essentially free of a tetrahydrofuran-insoluble portion.
Claims20
An electrostatic image developing toner, comprising:
- a polyester binder resin comprising at least one polyol crosslinked with at least one polycarboxyl group, wherein at least one of said polyol is an oxyalkylether of a novolak phenol resin;
- and
- said polyester binder resin contains 5 to 20% by weight of components having a weight-average molecular weight greater than about 1.times.10.sup.7 and is essentially free of a tetrahydrofuran-insoluble portion.
A method for preparing an electrostatic image developing toner, comprising the step of:
- forming toner particles comprising a polyester binder resin and at least one coloring agent, wherein said polyester binder resin contains at least one oxyalkylether of a novolak phenol resin crosslinked with at least one polycarboxyl group;
- contains 5 to 20% by weight of components having a weight-average molecular weight greater than about 1.times.10.sup.7 ;
- and is essentially free of a tetrahydrofuran-soluble portion.
Dependencies are inferred from the claim text.