Abstract: A natural oil-based toner resin for producing toner in developing electrophotographic image comprising a copolymer of unsaturated polyester resins and vinyl monomers, wherein the polyester resins have a molecular weight of 500 to 30000 and obtained from polycondensation between a polycarboxylic acid, a natural oil or derivative thereof and a polyol. The toner resin in emulsion form is mixed with fine suspensions or emulsions of a colorant and a charge control agent; and a flocculating agent is incorporated therein to induce aggregation for forming particles of desired sizes, and subsequently the temperature is suitably raised to cause coalescence to produce raw toner particles of regular shape and smooth surface. The raw toner particles are washed and dried, and treated with suitable additives to produce the finished product of chemically produced toner.

Abstract: A method of synthesizing polyester toner resins comprises: polycondensing polycarboxylic acids, polyols and free fatty acids to form low molecular weight polyester resins with alkenyl group or hydroxyl group or a combination of both; wherein at least one of said polycarboxylic acids, said polyols or said free fatty acids derive from natural oils; crosslinking the polyester via alkenyl group with radical initiator and vinyl monomer or via hydroxyl group with diisocyanate to generate polyester of higher molecular weight and melting point; obtaining a first fraction with a molecular weight ranged between 3000 and 15000 and a second fraction with a molecular weight larger than 15000; and combining said first fraction with said second fraction to form said polyester toner resins.

Abstract: A method of synthesizing polyester toner resins comprises: polycondensing polycarboxylic acids, polyols and free fatty acids to form low molecular weight polyester resins with alkenyl group or hydroxyl group or a combination of both; wherein at least one of said polycarboxylic acids, said polyols or said free fatty acids derive from natural oils; crosslinking the polyester via alkenyl group with radical initiator and vinyl monomer or via hydroxyl group with diisocyanate to generate polyester of higher molecular weight and melting point; obtaining a first fraction with a molecular weight ranged between 3000 and 15000 and a second fraction with a molecular weight larger than 15000; and combining said first fraction with said second fraction to form said polyester toner resins.