Fixable toner with a modified bisphenolic polyester resin

A heat fixable toner comprising a binder resin and a graft-modified polyolefin as a release agent, wherein said binder resin comprises a bisphenolic polyester resin, said polyester resin being obtained by co-condensation of an acid component containing aromatic dicarboxylic acids in amounts of at least 30 mole % based on the total of said acid component and an alcohol component containing etherified bisphenols in amounts of at least 80 mole % based on the total of said alcohol component and having the properties that the melt viscosity .eta.' measured with an overhead flow tester is from 10.sup.3 to 10.sup.6 poise at a temperature within the temperature range of from 80.degree. C. to 120.degree. C. and an absolute value of the inclination of a graph is not more than 0.50 ln (poise)/.degree.C. when the natural logarithms ln.eta.' of the melt viscosity at 80.degree. C. and 120.degree. C. are plotted with respect to the temperatures;

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• said graft-modified polyolefin comprises an .alpha.-olefin polymer graft-modified with a grafting agent of from 0.1 to 100 parts by weight based on 100 parts by weight of the .alpha.-olefin polymer, wherein said grafting agent comprises from 20 to 80% by weight of a styrenic monomer and from 80 to 20% by weight of at least one monomer selected from the group consisting of methacrylic monomer, acrylic monomer, maleic monomer, fumaric monomer, itaconic monomer and citraconic monomer.