A method to make a chemically prepared crystalline polyester toner for use in electrophotography and more particularly to a method to make a multilayered crystalline polyester toner particle using a dual emulsion aggregation process. The dual emulsion aggregation process includes a first agglomeration step using an acid and a second agglomeration step using a soluble alkaline earth metal salt solution.

The present disclosure relates generally to a method to make a chemically prepared toner that employs a crash cooling process. In the crash cooling process, an amount of hot toner slurry is added to an external reactor holding an amount of chilled cooling water, wherein the temperature of the chilled cooling water in the external reactor is from about 8 C. to about 25 C. The amount of the chilled cooling water in the external reactor is about 10% to about 40% lower compared to the amount of the added hot toner slurry. Toner prepared using this crash cooling method is cooled at a rate of less than 0.8 C./min. Polyester toners and polyester core shell toners having a borax coupling agent between the toner core and toner shell made from this crash cooling processes using less water results in an improvement to the toner's print density and usage efficiency.

The present disclosure relates generally to a method to make a chemically prepared toner that employs a crash cooling process. In the crash cooling process, an amount of hot toner slurry is added to an external reactor holding an amount of chilled cooling water, wherein the temperature of the chilled cooling water in the external reactor is from about 8 C. to about 25 C. The amount of the chilled cooling water in the external reactor is about 10% to about 40% lower compared to the amount of the added hot toner slurry. Toner prepared using this crash cooling method is cooled at a rate of less than 0.8 C./min. Polyester toners and polyester core shell toners having a borax coupling agent between the toner core and toner shell made from this crash cooling processes using less water results in an improvement to the toner's print density and usage efficiency.

The invention provides a process for preparing core-shell composite particles comprising a polyester, polymerized ethylenically unsaturated silane compounds, and optionally a hydrophobic surface treatment. The invention further provides a composite particle comprising a polyester and a radically polymerized ethylenically unsaturated silane compound.

The magenta toner for developing electrostatic images includes colored resin particles containing a binder resin and a magenta colorant, and an external additive. A volume average particle diameter of the colored resin particles is from 5.5 m to 7.0 m. The external additive contains silica particles. The silica particles contain at least silica particles A having a number average particle diameter of from 5 nm to 30 nm and silica particles B having a number average particle diameter of from 31 nm to 100 nm; wherein a total content of the silica particles is from 0.5 part by mass to 4.5 parts by mass, with respect to 100 parts by mass of the colored resin particles. A liberation rate of the silica particles calculated by a specific liberation rate measuring method is in a range of from 2.2% to 9.5%.

A toner comprising a binder resin and a colorant, wherein the toner has a Martens hardness, as measured at a maximum load condition of 2.010.sup.4 N, of from 200 MPa to 1,100 MPa.

A toner comprising a toner particle comprising a binder resin, wherein a layer comprising an organosilicon condensate is present on the surface of the toner particle; the layer comprising the organosilicon condensate further comprises a reaction product of a compound comprising at least one metal element selected from all the metal elements belonging to Groups 3 to 13, and a polyhydric acid; in a backscattered electron image of the toner captured at a magnification of 50,000 times by using a scanning electron microscope, an average value of an area of the reaction product is from 10 nm.sup.2 to 5000 nm.sup.2, and a coefficient of variation of the area of the reaction product is not more than 10.0.

A toner includes toner particles. Each of the toner particles includes a composite core and a shell layer covering a surface of the composite core. Each of the composite cores is a composite of a toner core and foamable particles provided on a surface of the toner core. An amount of the foamable particles is at least 0.3% by mass relative to mass of the toner cores. Each of the foamable particles includes a base particle and a coat layer covering a surface of the base particle. The base particles are non-foamable. The coat layers include a foamable group. The foamable group is bonded to the surfaces of the base particles through a bond including a bond represented by formula OSi.

A chemically prepared multilayered toner composition, according to one example embodiment, includes a core having a first amorphous polyester resin, a second amorphous polyester resin, a colorant, and a release agent. A first layer is formed around the core wherein the first layer includes the same second amorphous polyester resin that is in the toner core. A second layer is formed on the surface of the first layer, wherein the second layer includes a third amorphous polyester resin. A borax coupling agent is between the first and second layers. In an embodiment the ratio of the second polymer in the core to second polymer in the first layer is about 50:50. The second layer can also be referred to as a shell that is formed over the toner particle having a center core, first layer and borax coupling agent. In another embodiment, the core does not contain a second amorphous polyester resin.

A chemically prepared multilayered toner composition, according to one example embodiment, includes a core having a first amorphous polyester resin, a second amorphous polyester resin, a colorant, and a release agent. A first layer is formed around the core wherein the first layer includes the same second amorphous polyester resin that is in the toner core. A second layer is formed on the surface of the first layer, wherein the second layer includes a third amorphous polyester resin. A borax coupling agent is between the first and second layers. In an embodiment the ratio of the second polymer in the core to second polymer in the first layer is about 50:50. The second layer can also be referred to as a shell that is formed over the toner particle having a center core, first layer and borax coupling agent. In another embodiment, the core does not contain a second amorphous polyester resin.