Toner for developing electrostatic latent image and method of manufacturing same, electrostatic latent image developer, cartridge, and image forming apparatus

A method of manufacturing a toner for developing an electrostatic latent image, the method comprising:

• adding a neutralizing agent and a water-based medium to a resin solution prepared by dissolving a non-crystalline polyester resin and a crystalline polyester resin in an organic solvent, thereby causing a phase inversion and generating an alkaline material;
• subsequently forming O/W emulsified resin particles;
• and
• aggregating and fusing a resin particle dispersion obtained by removing the organic solvent from the emulsified resin particles and a release agent particle dispersion to obtain a toner that comprises the crystalline polyester resin, the non-crystalline polyester resin and the release agent, wherein:
• an acid value of the crystalline polyester resin is within a range from 5 to 10 mgKOH/g;
• an acid value of the non-crystalline polyester resin is within a range from 10 to 15 mgKOH/g;
• a melting temperature of the crystalline polyester resin determined in accordance with ASTM D3418-8 is within a range from 50 to 120° C.;
• a weight average molecular weight (Mw) of the crystalline polyester resin is within a range from 10,000 to 25,000;
• a glass transition temperature (Tg) of the non-crystalline polyester resin determined in accordance with ASTM D3418-8 is 50° C. or higher;
• a weight average molecular weight (Mw) of the non-crystalline polyester resin is within a range from 20,000 to 50,000;
• a weight ratio between the crystalline polyester resin and the non-crystalline polyester resin is within a range from 5/95 to 40/60;
• and
• structures in which the crystalline polyester resin contacts the release agent exist in a ruthenium-stained cross section of the toner, and if a cross-sectional area of these structures is labeled A, a cross-sectional area of lone portions of the release agent is labeled B, and a cross-sectional area of lone portions of the crystalline polyester resin is labeled C, then 40≦100×A/(A+B+C)≦70, 10≦100×B/(A+B+C)≦30, and 20≦100×C/(A+B+C)≦30.

A toner cartridge comprising a toner for developing an electrostatic latent image, the toner comprising a crystalline polyester resin, a non-crystalline polyester resin and a release agent, wherein:

• an acid value of the crystalline polyester resin is within a range from 5 to 10 mgKOH/g;
• an acid value of the non-crystalline polyester resin is within a range from 10 to 15 mgKOH/g;
• a melting temperature of the crystalline polyester resin determined in accordance with ASTM D3418-8 is within a range from 50 to 120° C.;
• a weight average molecular weight (Mw) of the crystalline polyester resin is within a range from 10,000 to 25,000;
• a glass transition temperature (Tg) of the non-crystalline polyester resin determined in accordance with ASTM D3418-8 is 50° C. or higher;
• a weight average molecular weight (Mw) of the non-crystalline polyester resin is within a range from 20,000 to 50,000;
• a weight ratio between the crystalline polyester resin and the non-crystalline polyester resin is within a range from 5/95 to 40/60;
• and
• structures in which the crystalline polyester resin contacts the release agent exist in a ruthenium-stained cross section of the toner, and if a cross-sectional area of these structures is labeled A, a cross-sectional area of lone portions of the release agent is labeled B, and a cross-sectional area of lone portions of the crystalline polyester resin is labeled C, then 40≦100×A/(A+B+C)≦70, 10≦100×B/(A+B+C)≦30, and 20≦100×C/(A+B+C)≦30.