Numerous processes are within the purview of those skilled in the art for the preparation of toners. Emulsion aggregation (EA) is one such method. Emulsion aggregation toners may be used in forming print and/or electrophotographic images. Emulsion aggregation techniques may involve the formation of a polymer emulsion by heating a monomer and undertaking a batch or semi-continuous emulsion polymerization, as disclosed in, for example, U.S. Pat. No. 5,853,943, the disclosure of which is hereby incorporated by reference in its entirety. Emulsion aggregation/coalescing processes for the preparation of toners are illustrated in a number of patents, such as U.S. Pat. Nos. 5,290,654, 5,278,020, 5,308,734, 5,344,738, 6,593,049, 6,743,559, 6,756,176, 6,830,860, 7,029,817, and 7,329,476, and U.S. Patent Application Publication Nos. 2006/0216626, 2008/0107989, 2008/0107990, 2008/0236446, and 2009/0047593. The disclosures of each of the foregoing patents are hereby incorporated by reference in their entirety.
Polyester EA ultra low melt (ULM) toners have been prepared utilizing amorphous and crystalline polyester resins as illustrated, for example, in U.S. Patent Application Publication No. 2008/0153027, the disclosure of which is hereby incorporated by reference in its entirety.
Conventional ULM polyester based toners result in a minimum fusing temperature (MFT) reduction of about 20 degrees Celsius, which enables reduction in fuser energy and life. The reduction in MFT is primarily achieved by the introduction of a crystalline resin component in amounts from about 5 to about 10 percent. Although adding more crystalline resin (about 10 to about 20 percent) may reduce the MFT even further, its crystalline properties, i.e., conductivity, degrades electrical performance.
Further reduction of the MFT of toners, without degradation of the electrical performance of toners, together with environmentally friendly toners, remain desirable.