A toner, comprising a toner particle, wherein the toner particle has a core-shell structure comprising a core particle and a shell on a surface of the core particle, the shell comprises a polymer having monomer units represented by Formula (I) below, the toner comprises a specific external additive A, the external additive A is at least one selected from the group consisting of silica fine particles and organosilicon polymer fine particles, and a ratio of coverage of a surface of the toner particle with the external additive A is 0.3 area % or higher:

##STR00001## in Formula (I), L.sup.1 represents —COO(CH.sub.2).sub.n— (where n is an integer of 1 to 10), and carbonyl of L.sup.1 is bonded to a carbon atom of a main chain; R.sup.1 represents hydrogen or a methyl group; and R.sup.2 to R.sup.10 represent each independently an alkyl group having 1 to 4 carbon atoms.

An image forming method includes a charging step, an image exposure step, a developing step, a transferring step, a cleaning step, and a fixing step. A toner contains toner particles, the toner particles contain a resin A including a unit A1 including an alkyl group having 18 to 36 carbon atoms in the side chain, and the electrophotographic photoreceptor includes a surface layer containing (i) fluorine-containing resin particles and (ii) a fluorine-based polymer B.

Provided is a compound which is fluidized by light irradiation and is less colored. The compound is a compound represented by the following general formula (1), which is fluidized by light irradiation:

R.sub.1—CH═N—R.sub.2  General Formula (1)

wherein R.sub.1 is a substituted or unsubstituted cyclic hydrocarbon group or a substituted or unsubstituted heterocyclic group; and R.sub.2 is a substituted or unsubstituted heterocyclic group containing a nitrogen atom bonded to the nitrogen atom in the general formula (1).

A photoresponsive polymer includes a structural unit represented by the following general formula (1), the photoresponsive polymer being fluidized by light irradiation, and reversibly non-fluidized:

[Chemical formula 1]

R.sub.1—Z.sub.1═Z.sub.2—R.sub.2  General formula (1) in the formula, Z.sub.1 and Z.sub.2 each represent CH or N, and Z.sub.1≠Z.sub.2, R.sub.1 represents an aromatic hydrocarbon group having a substituent R.sub.a selected from the group consisting of an alkyl group, an alkoxy group, and a halogen atom at each of two ortho positions with respect to Z.sub.1, R.sub.2 represents an aromatic heterocyclic group with or without a substituent, and at least one of the R.sub.1 and the R.sub.2 is bonded to a group containing a structure derived from a polymerizable group.

Latexes are provided which may comprise water and resin particles comprising a polymerization product of reactants comprising a dioxane/dioxolane monomer and a vinyl co-monomer, wherein the dioxane/dioxolane monomer is an ester of (meth)acrylic acid with an alcohol comprising a dioxane moiety, an ester of (meth)acrylic acid with an alcohol comprising a dioxolane moiety, or both.

The toner is characterized in that, wherein the binder resin is a resin satisfying at least one of the following specification (A) or (B): (A) the binder resin contains a crystalline resin having a unit (a) represented by the following formula (1) and a resin having a sulfide structure; and (B) the binder resin contains a crystalline resin having the sulfide structure and having the unit (a) represented by the following formula (1):

##STR00001##

wherein the colorant is any colorant selected from the specific group consisting of: carbon black and so on, wherein when the toner is subjected to measurement with a differential scanning calorimeter, a peak temperature of a maximum endothermic peak is present in a range of from 50° C. or more to 70° C. or less, and wherein the maximum endothermic peak has an endothermic quantity of 30 J/g or more and 70 J/g or less.

Provided is a positive-charging toner having a toner particle that contains a binder resin, the binder resin contains a polymer A having a first monomer unit derived from a first polymerizable monomer, and a second monomer unit derived from a second polymerizable monomer, the first polymerizable monomer is at least one selected from the group consisting of (meth)acrylic acid esters having a C18 to C36 alkyl group, the content of the first monomer unit in the polymer A is 5.0 to 60.0 mol % and the content of the second monomer unit is 20.0 to 95.0 mol %, SP.sub.11 of the first monomer unit and SP.sub.21 of the second monomer unit satisfy 3.00≤(SP.sub.21−SP.sub.11)≤25.00, and the work function of the toner is 5.0 to 5.4 V.

Provided is a toner comprising a toner particle containing a binder resin, a resin A, and a pigment, wherein the resin A has a pKa of at least 6.0 and not more than 9.0, and also has a hydrophobic parameter HPA of at least 0.65 and not more than 0.95.

Novel support material formulations, characterized as providing a cured support material with improved dissolution rate, while maintaining sufficient mechanical strength, are disclosed. The formulations comprise a water-miscible non-curable polymer, a first water-miscible, curable material and a second, water-miscible material that is selected capable of interfering with intermolecular interactions between polymeric chains formed upon exposing the first water-miscible material to curing energy. Methods of fabricating a three-dimensional object, and a three-dimensional object fabricated thereby are also disclosed.

A toner comprising a toner particle comprising a binder resin including a polyester resin, and a polyolefin resin having a sulfonic acid group, wherein the polyolefin resin having a sulfonic acid group is a polymer in which a vinyl polymer is bonded to a polyolefin, a content ratio of a monomer unit containing a sulfonic acid group in the vinyl polymer is from 1.0 mass % to 20.0 mass %, in a FT-IR spectrum obtained through measurement of a large particle size toner and a small particle size toner resulting from dividing, on a number basis, the toner into two substantially equal parts, a ratio of an intensity of a maximum absorption peak in a range from 1130 cm.sup.−1 to 1170 cm.sup.−1 with respect to an intensity of a maximum absorption peak in a range from 1713 cm.sup.−1 to 1723 cm.sup.−1 exhibits a specific relationship.