Toner having crosslinkages and method of fixing same

A fixing method comprising fixing a toner image on a sheet by applying heat and pressure,

• wherein the toner comprises a binder resin and a metal salt or a metal complex;
• wherein the toner has:
• a dynamic modulus G'.sub.120-200 at 120-200.degree. C. of 2.times.10.sup.3 or higher to below 5.times.10.sup.5 [dyne/cm.sup.2 ] as measured in the frequency range of 1.times.10.sup.-2 -1 (Hz);
• a loss modulus G".sub.120-200 at 120-200.degree. C. of 2.times.10.sup.3 or higher to below 5.times.10.sup.5 [dyne/cm.sup.2 ] as measured in the frequency range of 1.times.10.sup.-2 -1 (Hz);
• a dynamic modulus G'.sub.200 at 200.degree. C. and a frequency f satisfying an approximated linear relationship according to the least squares method of:
• log G'.sub.200 =a.multidot.log.multidot.f+log b,
• wherein a denotes a positive number of 0.25 or smaller and b denotes a constant;
• and
• a ratio (G'.sub.200)/G'.sub.120) of below 0.25 wherein (G'.sub.200) denotes a dynamic modulus at 200.degree. C. and (G'.sub.120) denotes a dynamic modulus at 120.degree. C. respectively at a frequency of 1 (Hz);
• and
• wherein the binder resin comprises a copolymer or a mixture thereof comprising polymerized units of a carboxyl group-containing monomer and having crosslinkages including a metallic crosslinkage and a polymeric crosslinkage.