The present invention relates to a polycarbonate of number average molecular weight from 500 to 10000, glass transition point from 30 to 80° C. and hydroxyl group value of 30 mg KOH/g or less and the use of said polycarbonate in a urethane modified resin used as an ingredient for the production of a toner or a developer for electronic copying purposes. The present invention also relates to a urethane modified resin obtainable by the reaction of a polymer mixture comprising a polycarbonate according to any of claims 1 to 5 and a polycondensed resin of glass transition point from 10 to 60° C. and hydroxyl group value from 20 to 100 mg KOH/g with a polyfunctional isocyanate compound wherein the ratio of polycarbonate and polycondensed resin is from 20:80 to 80:20 by weight and the molar ratio of isocyanate groups in the polyisocyanate compound to hydroxyl groups in the polymer mixture is between 0.4 to 1.2:1 as well as a toner for electronic copying purposes comprising said urethane modified polycarbonate based resin and a developer comprising said toner and optionally a carrier.