A toner having an inorganic fine particle and a toner particle containing a binder resin, wherein 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 that is different from the first polymerizable monomer, the first polymerizable monomer is selected from the (meth)acrylic acid esters each having a C.sub.18-36 alkyl group, the content of the first monomer unit in the polymer A is within a specific range, the SP value of the first monomer unit and the SP value of the second monomer unit are in a specific relationship to one another, the inorganic fine particle is surface treated with a compound having an alkyl group, and the volume resistivity of the inorganic fine particle is within a specific range.

Provided is a toner has a toner particle containing a binder resin and is characterized in that the binder resin contains a polymer A, which is a polymer of a composition containing a first polymerizable monomer, a second polymerizable monomer and a crosslinking agent, the first polymerizable monomer is at least one monomer selected from the group consisting of (meth)acrylic acid esters having an alkyl group with 18 to 36 carbon atoms, the crosslinking agent has two or more polymerizable double bonds, a content of the first polymerizable monomer in the composition is 5.0 to 60.0 mol %, a content of the second polymerizable monomer is 20.0 to 95.0 mol %, and when the SP values of the first polymerizable monomer, the second polymerizable monomer and the crosslinking agent are denoted by SP.sub.12, SP.sub.22 and SP.sub.C2, respectively, the formulae 0.60(SP.sub.22SP.sub.12)15.00 and SP.sub.12<SP.sub.C2<(SP.sub.22+3.00) are satisfied.

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.21SP.sub.11)25.00, and the work function of the toner is 5.0 to 5.4 V.

A toner comprising a toner particle containing a binder resin, the storage elastic modulus Gt (150) of the toner at 150 C. is at least 1.010.sup.4 Pa, 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 different from the first polymerizable monomer, the first polymerizable monomer is selected from specific (meth)acrylic acid esters, the contents of the first monomer unit and second monomer unit in the polymer A are within specific ranges, and the SP values of the first monomer unit and second monomer unit are within specific ranges.

Provided is a two-component developer has a toner including a toner particle including a binder resin, and a magnetic carrier, wherein the binder resin includes 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 different from the first polymerizable monomer, the first polymerizable monomer is a specific (meth)acrylic acid ester, a content and an SP value of the first and second monomer units in the polymer A fall within respective specific ranges, the magnetic carrier has a magnetic core and a coating resin of the surface of the magnetic core, the coating resin includes a polymer B having monomer units (a) and (b), each SP value of the monomer units (a) and (b) is a specific value.

The present invention provides an electrophotographic toner binder containing, as a main component, a polymer whose constituent monomer is a monomer having an ethylenically unsaturated bond, the electrophotographic toner binder being excellent in low-temperature fixability, hot-offset resistance, and storage stability. The present invention provides an electrophotographic toner binder containing a polymer (A) containing a monomer (a) and a monomer (x) different from the monomer (a) as essential constituent monomers, wherein the monomer (a) is a (meth)acrylate having a C18-C36 acyclic hydrocarbon group, the polymer (A) has an acid value of 40 or less, and the polymer (A) satisfies the following relational expression (1):
1.1 (cal/cm.sup.3).sup.0.5|SP(x)SP(a)|8.0 (cal/cm.sup.3).sup.0.5relational expression (1):
wherein SP(a) is the SP value of a structural unit derived from the monomer (a) constituting the polymer (A); and
SP(x) is the SP value of a structural unit derived from the monomer (x) different from the monomer (a) constituting the polymer (A).

The present invention provides an electrophotographic toner binder containing, as a main component, a polymer whose constituent monomer is a monomer having an ethylenically unsaturated bond, the electrophotographic toner binder being excellent in low-temperature fixability, hot-offset resistance, and storage stability. The present invention provides an electrophotographic toner binder containing a polymer (A) containing a monomer (a) and a monomer (x) different from the monomer (a) as essential constituent monomers, wherein the monomer (a) is a (meth)acrylate having a C18-C36 acyclic hydrocarbon group, the polymer (A) has an acid value of 40 or less, and the polymer (A) satisfies the following relational expression (1):

1.1 (cal/cm.sup.3).sup.0.5|SP(x)SP(a)|8.0 (cal/cm.sup.3).sup.0.5relational expression (1):

wherein SP(a) is the SP value of a structural unit derived from the monomer (a) constituting the polymer (A); and
SP(x) is the SP value of a structural unit derived from the monomer (x) different from the monomer (a) constituting the polymer (A).

An electrostatic charge image developing toner has a surface property index value represented by Formula S of 2.0 to 2.8, an electrostatic charge image developing toner has a surface property index value represented by Formula S of more than 2.8 and 3.5 or less, and an electrostatic charge image developing toner has a surface property index value represented by Formula S of more than 1.0 and less than 2.0 and a calculated value of a specific surface area in Formula S of 0.70 to 1.3:

(Surface property index value)=(Measured value of specific surface area)/(Calculated value of specific surface area)Formula S wherein (Calculated value of specific surface area)=(Sum of surface areas calculated from equivalent circle diameters of 4,500 toner particles in flow type particle image analysis)/{((Specific gravity of toner)(Sum of volumes calculated from equivalent circle diameters of 4,500 toner particles in flow type particle image analysis)}.

A toner is provided that contains a crystalline polyester resin comprising a polycondensed resin of a dicarboxylic acid represented by the following formula (1) with a diol represented by the following formula (2). A content of a cyclic ester represented by the following formula (3) in the toner, measured by a thermal extraction gas chromatographic mass spectrometry at a thermal extraction temperature of 160 C., is from 1 to 200 ppm in terms of toluene:

##STR00001##

where n represents an integer of from 2 to 12;

##STR00002##

where m represents an integer of from 2 to 12; and

##STR00003##

where n represents an integer of from 2 to 12, m represents an integer of from 2 to 12, and m+n6 is satisfied.

The present disclosure relates to a liquid electrophotographic composition comprising: a polymer resin comprising a side group comprising a cross-linkable moiety; and a carrier liquid.