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.

A toner includes a toner particle containing a resin component. The resin component contains an ester group-containing olefin copolymer and an acid group-containing olefin copolymer. For example, the ester group-containing olefin copolymer is an ethylene-vinyl acetate copolymer, and the acid group-containing olefin copolymer is an ethylene-methacrylic acid copolymer. The acid group-containing olefin copolymer has an acid value of 50 to 300 mg KOH/g. The content of the ester group-containing olefin copolymer in the resin component is 50 mass % or more based on the total mass of the resin component. The content of the unit derived from the vinyl acetate is 3 mass % or more and 35 mass % or less based on the total mass of the ester group-containing olefin copolymer.

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 method for producing a composite resin particle dispersion includes: polymerizing a (meth)acrylic acid ester compound to form a (meth)acrylic acid ester-based resin; and polymerizing a styrene compound and a vinyl monomer other than the styrene compound in the presence of the (meth)acrylic acid ester-based resin to form composite resin particles containing a styrene-based resin and the (meth)acrylic acid ester-based resin. The mass ratio of the styrene-based resin to the (meth)acrylic acid ester-based resin in the composite resin particles is from 80:20 to 20:80. A difference between the lowest glass transition temperature and the highest glass transition temperature in the composite resin particles is 30° C. or more.

A particle set for producing a printed matter includes: a chromatic color toner containing toner particles A; and pressure-responsive particles containing base particles B, in which the base particles B contain a styrene resin containing, as polymerization components, styrene and a vinyl monomer other than styrene, and a (meth)acrylate resin containing, as a polymerization component, a (meth)acrylate, a mass ratio of the styrene resin to the (meth)acrylate resin (styrene resin:(meth)acrylate resin) is 80:20 to 20:80, a difference between the lowest glass transition temperature and the highest glass transition temperature of the pressure-responsive particles is 30° C. or more, and when the toner particles A have a volume average particle diameter D50A and the base particles B have a volume average particle diameter D50B, the D50A and the D50B satisfy formula 1-1: 1.5 μm<(D50B−D50A).

A toner containing a toner particle that contains a binder resin including a polyester resin, and a polyolefin resin having —COOM that is a neutralized carboxy group with a monovalent metal ion M, wherein the polyolefin resin having —COOM is a polymer in which a vinyl polymer is bonded to a polyolefin, a content of a monomer unit containing —COOM in the polyolefin resin having —COOM is 1 to 20 mass %, and in a FT-IR spectrum obtained through measurement of a large particle size-side particle group and a small particle size-side particle group obtained by dividing the toner into two substantially equal parts, on a number basis, a ratio of the intensity of a maximum absorption peak in a range from 1545 cm.sup.−1 to 1555 cm.sup.−1 with respect to the intensity of a maximum absorption peak in a range from 1713 cm.sup.−1 to 1723 cm.sup.−1 exhibits a specific relationship.

Disclosed herein is a toner composition, developer and additive for a toner composition. The toner composition includes toner particles having at least one resin, an optional colorant, an optional wax, and a crosslinked polymer particle on at least a portion of an external surface of the toner particles. The crosslinked polymeric particle on a surface of the toner particles includes at least a hydrophobic monomer comprising a non-fluorinated monomer having a carbon to oxygen (C/O) ratio of 3 or greater or a fluorinated monomer. The crosslinked polymer particle includes a second monomer comprising two or more vinyl groups present in an amount from about 8 wt % to about 40 wt % of the copolymer, a metal oxide and optionally a charge control agent monomer.

A toner containing a toner particle including a binder resin, a resin A having a pKa of 6.0-9.0, and a pigment having a pKb of 4.0-7.0, wherein the pKa is an acid dissociation constant measured by preparing a resin solution in which 1.0 part by mass of the resin A, 70.0 parts by mass of toluene and 30.0 parts by mass of ethanol are mixed, and carrying out neutralization titration with a potassium hydroxide ethanol solution of 0.1 mol/L, and the pKb is a basic dissociation constant measured by preparing a pigment dispersion in which 10.0 parts by mass of the pigment, 140.0 parts by mass of toluene and 60.0 parts by mass of ethanol are mixed, and carrying out neutralization titration with a hydrochloric acid ethanol solution of 0.1 mol/L.

A toner comprising a toner particle containing a pigment, a resin A and a resin B, wherein the pigment is a pigment having a structure derived from a basic compound, the resin A has an acidic functional group, the resin B has an acid value of at least 2.0 mg KOH/g, the resin B has a glass transition temperature TgB of at least 50° C., and the hydrophobic parameter HPA of the resin A and the hydrophobic parameter of the resin B satisfy the following formulae:

HPA≧0.60

HPB≦0.70

HPA−HPB>0.

A magnetic carrier including a magnetic core and a coating resin configured to coat the surface of the magnetic core. The coating resin contains a graft resin A and a graft resin B. The coating resin (i) contains 1.0 mass % or more and 50.0 mass % or less of the graft resin A, and (ii) contains 50.0 mass % or more and 99.0 mass % or less of the graft resin B. The graft resin A has a unit Y1 represented by formula (1) and a unit Y2 represented by formula (2). The graft resin B (i) is a comb-shaped polymer having, as a branch, at least one moiety selected from, for example, a styrene-based polymer moiety and a (meth)acrylate-based polymer moiety, and (ii) contains the polysiloxane structure moiety at a content of 0.1 mass % or less.

##STR00001##