(57) A toner suitable for developing an electrostatic latent image is described comprising
(a) a polyester containing not less than 5% by weight of chloroform-insoluble component
as binder resin and either (b) at least one of a first mold release agent which has
the general formula;
wherein R1 and R2 are independently a saturated or unsaturated aliphatic hydrocarbon group having not
less than 10 carbon atoms, R3 and R4 are independently a hydrogen atom or a group represented by -OCRs wherein R5 is a saturated or unsaturated hydrocarbon group and n is a positive integer, or (c)
a mixture of a second mold release agent which contains at least 20% by weight of
ester component, the needle penetration degree of said mold releasing agent being
not more than 4, and a third mold release agent which is a polyolefin was or a compound
of the general formula given above.
2. A toner according to claim 1 in which in component (b) n is from 1 to 5.
3. A toner according to claim 1 or 2 in which in component (b) R, and/or R2 contains 10 to 23 carbon atoms.
4. A toner according to any one of claims 1 to 3 which contains 1 to 10% by weight
of mold release agent.
5. A toner according to any one of claims 1 to 4 in which the second mold release
agent is a wax having a melting point of 60 to 110°C.
6. A toner according to any one of claims 1 to 5 in which in component (c) the weight
ratio of the ...
|
