A polymeric composition including a copolymer comprising a first monomer having a high carbon to oxygen ratio of from about 3 to about 8; a second monomer comprising two or more vinyl groups, wherein the second monomer is present in the copolymer in an amount of from greater than about 8 percent by weight to about 60 percent by weight, based on the weight of the copolymer; and, optionally, a third monomer comprising an amine, wherein the third monomer, if present, is present in an amount of from about 0.5 percent by weight to about 5 percent by weight, based on the weight of the copolymer. A toner including the copolymer as a toner surface additive. An emulsion aggregation toner process including the copolymer as a toner surface additive.

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.

An image forming apparatus including an image forming unit, a unit holder, and circuitry is provided. The image forming unit includes a color toner unit, a replaceable black toner unit, and a replaceable special toner unit that form a color toner image, a black toner image, and a special toner image, respectively. The unit holder selectively and detachably holds the replaceable black toner unit or the replaceable special toner unit. The circuitry controls the image forming unit to perform: a normal operation, when the unit holder holds the replaceable black toner unit, that forms a color-black image; a special operation, when the unit holder holds the replaceable special toner unit, that forms a color-special image; and a toner amount increase control that increases an amount of the color toner per unit area in the color toner image in the special operation than that in the normal operation.

A toner has a toner particle including a binder resin, the binder resin includes a polymer A, the polymer A contains 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 selected from (meth)acrylic acid esters having an alkyl group having 18 to 36 carbon atoms, the content of the first monomer unit in the polymer A is 5.0 mol % to 60.0 mol %, the content of the second monomer unit in the polymer A is 20.0 mol % to 95.0 mol %, the SP value of the first monomer unit and the SP value of the second monomer unit satisfy a predetermined relationship, the polymer A includes a predetermined polyvalent metal, and the content of the polyvalent metal is 25 ppm to 500 ppm.

A toner has a toner particle including a binder resin, the binder resin includes a polymer A, the polymer A contains 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 selected from (meth)acrylic acid esters having an alkyl group having 18 to 36 carbon atoms, the content of the first monomer unit in the polymer A is 5.0 mol % to 60.0 mol %, the content of the second monomer unit in the polymer A is 20.0 mol % to 95.0 mol %, the SP value of the first monomer unit and the SP value of the second monomer unit satisfy a predetermined relationship, the polymer A includes a predetermined polyvalent metal, and the content of the polyvalent metal is 25 ppm to 500 ppm.

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 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).

Provided is toner which has good low-temperature fixability, shelf stability and hot offset resistance, and which suppresses a decrease in glossiness of an image. The toner comprising colored resin particles containing a binder resin, a colorant, a softening agent and a charge control agent, and an external additive, wherein a glass transition temperature (Tg) specified from a temperature dependence curve of a loss tangent (tan ?) obtained by dynamic viscoelastic measurement of the toner, is 50? C. or more and less than 90? C.; the loss tangent (tan ?) at the glass transition temperature (Tg) is 1.70 or less; in a temperature range of 90? C. or more and 160? C. or less, a lowest temperature (Ta) with a loss tangent of 1.50 is more than 95? C. and less than 145? C.; and a storage elastic modulus (G) at the lowest temperature (Ta) is less than 56000 Pa.

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).