A positively chargeable 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 containing a binder resin and a colorant layer disposed over a surface of the toner core. The colorant layers contain carbon black. The colorant layers have a thickness of at least 200 nm and no greater than 500 nm. The shell layers include a repeating unit having a non-ring-opened oxazoline group. An amount of the non-ring-opened oxazoline group contained in 1 g of the positively chargeable toner as measured by gas chromatography-mass spectrometry is at least 500 mol and no greater than 1,000 mol.

A toner includes toner particles. The toner particles each include a core, a shell layer, and an external additive. The core contains a first thermoplastic resin as a binder resin. The shell layer partially covers a surface of the core. The external additive is attached to regions of the surface of the core that are not covered with the shell layer. The external additive includes external additive particles. The external additive particles protrude outward in radial directions of the core further than a surface of the shell layer. At least part of surfaces of the external additive particles is exposed from the shell layer. The shell layer contains a second thermoplastic resin or a thermosetting resin. The second thermoplastic resin has a higher softening point than the core. The shell layer has a thickness of at least 5 nm.

The present disclosure relates generally to a method to make a chemically prepared toner that employs a crash cooling process. In particular, the crash cooling process involves the addition of a toner slurry having a temperature between 70 C. and 90 C. to an equivalent amount of cold water having a temperature between 5 C. and 20 C. Polyester and styrene acrylic toners as well as polyester core shell toners having a borax coupling agent between the toner core and toner shell made from this cooling process results in an improvement to the amount of toner waste, thereby achieving a higher toner usage efficiency for an electrophotographic printing system.

Toner particles each include a toner mother particle and an external additive. The toner mother particle includes a toner core containing a binder resin and a shell layer covering a surface of the toner core. The external additive includes a plurality of external addition resin particles. The external addition resin particles are each present on a surface of the shell layer. The shell layer contains a specific vinyl resin. The toner core and each resin particle are bonded together through a covalent bond within the shell layer. A detachment rate of the resin particles is lower than 5%. The vinyl resin include constitutional units represented by formulas (1-1) to (1-3). The atomic groups X.sup.1 and X.sup.2 included in the constitutional units represented by the respective formulas (1-1) and (1-2) are each derived from N-methylol group and represented by NHCH.sub.2O. ##STR00001##

A magnetic toner includes toner particles. The toner particles each include a toner core and a shell layer covering a surface of the toner core. The toner cores contain a polyester resin and a magnetic powder. The magnetic powder includes specific magnetic particles. The shell layers contain a specific vinyl resin.

A positively chargeable 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 containing a binder resin and a colorant layer disposed over a surface of the toner core. The colorant layers contain carbon black. The colorant layers have a thickness of at least 200 nm and no greater than 500 nm. The shell layers include a repeating unit having a non-ring-opened oxazoline group. An amount of the non-ring-opened oxazoline group contained in 1 g of the positively chargeable toner as measured by gas chromatography-mass spectrometry is at least 500 mol and no greater than 1,000 mol.

Provided is a toner comprising a toner particle including a toner base particle and fine particles present on a surface of the toner base particle, wherein each of the fine particles includes a core fine particle and a condensate of at least one organosilicon compound selected from the group consisting of organosilicon compounds represented by specific structural formulas, the condensate coating the surface of the core fine particle, and in a wettability test of the toner with respect to a methanol/water mixed solvent, a methanol concentration, when a transmittance of light having a wavelength of 780 nm is 50%, is 5.0 to 20.0% by volume: ##STR00001## in above Formulas, each of R.sup.a, R.sup.b and R.sup.c independently represents an alkyl group, an alkenyl group, an acetoxy group, an acyl group, an aryl group, or a methacryloxyalkyl group, R.sup.1 to R.sup.5 each independently represents a halogen atom or an alkoxy group.

A toner includes toner particles. The toner particles each include a core, a shell layer, and an external additive. The core contains a first thermoplastic resin as a binder resin. The shell layer partially covers a surface of the core. The external additive is attached to regions of the surface of the core that are not covered with the shell layer. The external additive includes external additive particles. The external additive particles protrude outward in radial directions of the core further than a surface of the shell layer. At least part of surfaces of the external additive particles is exposed from the shell layer. The shell layer contains a second thermoplastic resin or a thermosetting resin. The second thermoplastic resin has a higher softening point than the core. The shell layer has a thickness of at least 5 nm.

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.

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, hot toner slurry is added to an external reactor containing a coolant comprised of previously cooled toner slurry in combination with cooled de-ionized water. The previously cooled toner slurry found in the coolant has the same toner composition as the incoming hot toner slurry. Also, the amount of the coolant in the external reactor is equivalent to the amount of incoming hot toner slurry. Polyester toners and polyester core shell toners having a borax coupling agent between the toner core and toner shell made from this crash cooling process results in an improvement to the toner performance especially a decrease in the overall toner usage.