The present invention provides a compound and a pigment dispersant, each of which improves the dispersibility of various types of pigments in a non-aqueous solvent and also provides a pigment composition, a pigment dispersion, and a toner, each of which has a preferable coloring power. The compound includes a polymer which has a monomer unit having a specific structure and also includes a specific partial structure.

The present invention provides a toner that exhibits an excellent colorant dispersibility and hence maintains the formation of a high-quality image, that is capable of low-temperature fixing, and that has a satisfactory heat-resistant storability and a satisfactory durability, in which the toner comprising a toner particle that contains a colorant and a binder resin containing a styrene-acrylic resin and a crystalline resin, wherein a compatibility parameter (V) between the styrene-acrylic resin and the crystalline resin satisfies 0.40≦V≦1.10.

Provided is a toner that uses a crystalline resin, and demonstrates favorable dispersibility of the crystalline resin in the toner, demonstrates superior low-temperature fixability, and is able to inhibit fogging. The toner has a toner particle comprising a resin A, which has a long-chain alkyl group having an average number of carbon atoms of 27 to 50, and a crystalline resin, wherein the SP value (cal/cm.sup.3).sup.1/2 of the crystalline resin is 9.00 to 12.00, and in a GC/MS analysis of components that volatize when the toner is heated for 10 minutes at 200° C., the amount of volatile components of saturated hydrocarbons having 30 to 37 carbon atoms is 90 ppm to 260 ppm of toluene equivalent, based on mass.

A toner having a toner particle containing a binder resin and a crystalline material, wherein when “a” is an endothermic quantity deriving from the crystalline material in a DSC of the toner and “b” is an endothermic quantity deriving from the crystalline material in a DSC of the toner that has been held for 10 hours in an environment with a temperature of 55° C. and a humidity of 8% RH, the “a” and “b” satisfy a relationship a/b≧0.85; in a dynamic viscoelastic measurement of a non-melt-molded pellet of the toner, the toner has a temperature range A for which G″≦1×10.sup.5 Pa and tan δ<1 are satisfied; and in a dynamic viscoelastic measurement of a melt-molded pellet of the toner, the toner has a temperature range B for which tan δ>1 is satisfied within the temperature range A.

Provided is a toner containing a binder resin. The binder resin contains a crystalline resin. The toner has a maximum endothermic peak temperature (P1) of from 50° C. to 80° C. and a total endothermic amount (Q) of from 35 J/g to 90 J/g at a first temperature elevation of differential scanning calorimetry. A ratio (Q.sub.p/Q) of a total endothermic amount (Q.sub.p) of the toner in a temperature range of from 20° C. to the maximum endothermic peak temperature (P1) to the total endothermic amount (Q) of the toner is from 0.65 to 0.83.

A toner includes toner particles. The toner particles each include a toner mother particle. The toner mother particles contain a binder resin and a magnetic powder. The binder resin includes a polyester resin, a vinyl resin, and a block polymer. The block polymer includes a polyester portion, a vinyl polymer portion, and a linker that links the polyester portion and the vinyl polymer portion. The linker is derived from a specific compound having a vinyl group and at least one of a carboxy group and an alcoholic hydroxyl group. The magnetic powder has an octahedral structure.

A block copolymer includes a crystalline polyester block and an amorphous polyalkylsiloxane block, the block copolymer exhibiting baroplastic behavior. The block copolymer is used in a cold pressure fix toner. A method of making a block copolymer including a crystalline polyester block and an amorphous polyalkylsiloxane block includes heating a mixture of a diacid, a diol, and a carbinol-terminated poly(alkylsiloxane).

Provided is a toner which provides excellent balance between high temperature storage stability and low temperature fixability and which is less likely to cause the bleeding out of a release agent even in a long-term, high-temperature condition. Disclosed is a toner for developing electrostatic images, comprising: colored resin particles comprising a binder resin, a colorant and a release agent, and an external additive, wherein the colored resin particles further comprise a styrene-based thermoplastic elastomer, and wherein a content of a fatty acid ester compound having a number average molecular weight (Mn) of 500 or more and less than 2,000 as the release agent, is from 2 parts by mass to 20 parts by mass with respect to 100 parts by mass of the binder resin.

A toner for developing an electrostatic image includes a toner particle. The toner particle includes a binder resin and a black colorant. The binder resin includes a crystalline resin component. A toner layer formed through a deposition of the toner on a glass sheet in an amount of 6.5 g/m.sup.2 exhibits a light transmittance of 1 to 3% at a wavelength of 690 nm after applying heat at a temperature of 185° C. for five seconds to the toner layer from a position 100 μm away from a surface of the toner layer.

A toner is provided, which is obtained by heat treating a toner particle containing a crystalline polyester resin, an amorphous polyester resin, a hydrocarbon wax and a wax dispersant, wherein the crystalline polyester resin is a hybrid resin having crystalline polyester segments and amorphous vinyl segments, and a mass ratio of crystalline polyester segments and amorphous vinyl segments in the crystalline polyester resin (crystalline segments/amorphous segments) is 70/30 to 98/2.