A white toner having toner particles including: a resin; a BaSO.sub.4 pigment; wherein a particle size is defined as Span=(Dn90−Dn10)/(Dn50); and wherein the BaSO.sub.4 pigment has a wide particle size distribution wherein the Span is 0.75 or greater; and an optional wax. A pulverized (conventional) toner and an emulsion aggregation toner process.

A toner for developing an electrostatic charge image contains toner particles containing at least one binder resin; the Mg element in an amount such that in an x-ray fluorescence analysis of the toner, the net intensity of the peak for the Mg element is 0.10 kcps or more and 1.20 kcps or less; and at least one external additive including particles of at least one compound represented by formula (1),
MTiO.sub.3  (1)
where M represents at least one selected from the group consisting of Ca, Sr, and Ba.

Toner classification apparatus comprising classification rotor comprising a plurality of vanes extending from rotation center side of classification rotor to outer circumference side of classification rotor; the plurality of vanes are disposed with prescribed gaps established between vanes; gaps form opening facing rotation center region of classification rotor; each of vanes is disposed such that portion of vane away from of center of rotation of classification rotor is located on more upstream side in a direction of rotation of classification rotor than portion of vane closer to center of rotation of classification rotor; each of vanes has elbow; and in a horizontal cross section provided by sectioning classification rotor in a rotational axis perpendicular direction of classification rotor, shape of vane satisfies prescribed formulae, as well as toner production method comprising classification step of carrying out classification process on particles to be classified by using toner classification apparatus.

Provided is a toner blend composition comprising a first pigmented toner and a second toner that is devoid of any pigment additive, i.e., a ‘non-pigmented or clear toner’. The non-pigmented or clear toner is about 1% to about 15% by weight of the toner blend composition. The resulting inventive toner blend composition surprisingly exhibits similar print density on a page compared to a fully pigmented toner. Moreover, this toner blend composition exhibits improvement in toner usage per page, thus lowering toner cost compared to a fully pigmented toner. The non-pigmented or clear toner may be used in combination with either a monochrome or conventional toner using a carbon black pigment, or a chemically processed toners (‘CPT”) toners using a black pigment, magenta pigment, yellow pigment or a cyan pigment.

A toner for developing an electrostatic charge image contains toner particles containing at least one binder resin; the Mg element in an amount such that in an x-ray fluorescence analysis of the toner, the net intensity of the peak for the Mg element is 0.10 kcps or more and 1.20 kcps or less; and at least one external additive including particles of at least one compound represented by formula (1),

MTiO.sub.3  (1)

where M represents at least one selected from the group consisting of Ca, Sr, and Ba.

A toner classification apparatus comprising a classification rotor, wherein the classification rotor comprises a first vane group containing first vanes and a second vane group containing second vanes, the second vanes have a length shorter than the first vane group; the number of second vanes, which are disposed between two adjacent first vanes, is 1 to 2, independently; each of the first vanes draws first trajectory and each of the second vanes draws second trajectory when the classification rotor rotates, a distance from the center of rotation to an outer circumference side end of the first and second trajectory are defined as L1 and L3, respectively, and a distance from the center of rotation to the center side end of the first and second trajectory are defined as L2 and L4, respectively, L1 to L4 satisfy prescribed relationships, and a toner production method using the toner classification apparatus.

A toner classification apparatus comprising a classification rotor in which the classification rotor has a vane A which extends from a rotation center direction of the classification rotor to an outer circumference direction thereof and a vane B having a length longer than that of the vane A, the vane A, and the vane B are disposed so as to satisfy a predetermined relationship, and a toner production method comprising a classification step of carrying out a classification process on particles to be classified by using the toner classification apparatus.

To provide a magnetic core material and carrier for electrophotographic developer, which have small environmental dependence of the electric resistance, can suppress the carrier scattering, and can stably provide good images; a developer contains the carrier; and methods for producing them. The magnetic core material satisfying a value of Formula (1): a+b×10+c+d+e+f, being from 20 to 150, when a fluoride ion amount is denoted by a (ppm), a chloride ion amount is denoted by b (ppm), a bromide ion amount is denoted by c (ppm), a nitrite ion amount is denoted by d (ppm), a nitrate ion amount is denoted by e (ppm), and a sulfate ion amount is denoted by f (ppm), which are measured by a combustion ion chromatography method.

To provide a magnetic core material for electrophotographic developer and carrier for electrophotographic developer which have small environmental dependence of the electric resistance, can suppress the carrier scattering, and can stably provide good images; a developer contains the carrier; a method for producing the magnetic core material for electrophotographic developer; a method for producing the carrier for electrophotographic developer, and a method for producing the developer.

The magnetic core material for electrophotographic developer, satisfying a value of Formula (1): a+b10+c+d+e+f, being from 20 to 150, when a fluoride ion amount is denoted by a (ppm), a chloride ion amount is denoted by b (ppm), a bromide ion amount is denoted by c (ppm), a nitrite ion amount is denoted by d (ppm), a nitrate ion amount is denoted by e (ppm), and a sulfate ion amount is denoted by f (ppm), which are measured by a combustion ion chromatography method.

A toner for developing an electrostatic charge image, comprising a toner particle and an external additive, the toner particle comprising a binder resin containing a crystalline polyester resin, a colorant, and a release agent, the crystalline polyester resin comprising an alicyclic dibasic acid, a terephthalic acid, and an isophthalic acid as acid components and being contained in the toner particle in an amount of 4 to 8% by mass.