A toner comprising a binder resin and a colorant, wherein the toner has a Martens hardness, as measured at a maximum load condition of 2.010.sup.4 N, of from 200 MPa to 1,100 MPa.

Provided is a toner containing a colorant and a binder resin, wherein, in a wettability test of the toner with respect to a methanol/water mixed solvent, the methanol concentration when the transmittance of light at a wavelength of 780 nm is 50% is at least 5.0 volume % and not more than 30.0 volume %, and the interparticle force measured by rupturing a consolidation of the toner formed by compression of the toner with a load of 78.5 N is at least 1.0 nN and not more than 25.0 nN.

There is provided a toner containing: a toner particle containing a binder resin, a releasing agent, and a colorant; and an iron oxide particle present on a surface of the toner particle, in which the iron oxide particle has a surface containing a compound having a specific structure.

The present invention provides a three-dimensional printing article for making dental products and the preparation method thereof, which comprises: Ethoxylated bisphenol A dimethacrylate, Diurethane dimethacrylate, Triethylene glycol dimethacrylate, and Diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide. It not only improves the present time-consuming and labor-intensive dental device making, but also can be used in mass production of dental devices.

An electrostatic charge image developing white toner according to the present invention includes toner base particles including rutile type titanium oxide particles as colorant and a binder resin. The rutile type titanium oxide particles are composed of two groups Ga and Gb of rutile type titanium oxide particles have different volume particle size distribution. A volume particle size distribution curve of the rutile type titanium oxide particles represents diameter on a horizontal axis and volume ratio on a vertical axis and has two main peaks. Diameters Da and Db of peak top positions of the two main peaks are respectively within a range of 100 to 500 nm, and satisfy following Relational expressions:
(Relational expression 1):25 nmDbDa200 nm
(Relational expression 2):(mass of Ga):(mass of Gb)=5:95 to 30:70.

A plurality of toner particles each include a toner core, a shell layer covering a surface of the toner core, and a plurality of magnetic particles penetrating the shell layer. Each of the magnetic particles has an embedded portion and a protrusion portion. The embedded portions are embedded in the surface of the toner core. The protrusion portions are located further outward than the embedded portions in a radial direction of the toner particle and protrude outward from a surface of the shell layer in the radial direction of the toner particle. An average Heywood diameter X of the magnetic particles, a shell layer thickness Y, and an average value Z of protrusion heights of the respective magnetic particles satisfy relation (1) and relation (2) shown below.
0<Z(X/2)(1)
10 nmY50 nm(2)

Provided is a toner having a toner particle that contains a binder resin and a magnetic particle, wherein the magnetic particle satisfies the following stipulations (i) to (iii): (i) the magnetic particle has a prescribed shape and has a protruded portion on a plane portion thereof, (ii) the magnetic particle has a core particle that contains magnetite and has a coating layer, and (iii) the coating layer contains an iron-containing oxide and at least one of a silicon-containing oxide and an aluminum-containing oxide. In a molecular weight distribution measured on the tetrahydrofuran-soluble matter of the toner, the ratio (Mw/Mn) of a weight-average molecular weight to a number-average molecular weight is at least 10.0.

A magnetic toner containing a magnetic toner particle having a binder resin and a magnetic body, and inorganic fine particles, wherein when the inorganic fine particles are classified as first inorganic fine particles, second inorganic fine particles, and third inorganic fine particles in accordance with fixing strength thereof to the magnetic toner particle and in the sequence of the weakness of the fixing strength, the content of the first inorganic fine particles, the ratio of the second inorganic fine particles to the first inorganic fine particles, and the coverage ratio X of coverage of the magnetic toner surface by the third inorganic fine particles are in prescribed ranges.

An electrostatically charged image developing toner includes a particulate toner matrix containing an external additive on the surface of the particulate toner matrix. The external additive includes silica particles A and silica particles B. The silica particles A have a number average primary-particle diameter in the range of 40 to 100 nm and an average circularity in the range of 0.50 to 0.90, and are surface-modified with silicone oil. The silica particles B have a number average primary-particle diameter of 25 nm or more and smaller than the number average primary-particle diameter of the silica particles A, and are surface-modified with alkylalkoxysilane having a specific structure or silazane.

An electrostatic charge image developing white toner according to the present invention includes toner base particles including rutile type titanium oxide particles as colorant and a binder resin. The rutile type titanium oxide particles are composed of two groups Ga and Gb of rutile type titanium oxide particles have different volume particle size distribution. A volume particle size distribution curve of the rutile type titanium oxide particles represents diameter on a horizontal axis and volume ratio on a vertical axis and has two main peaks. Diameters Da and Db of peak top positions of the two main peaks are respectively within a range of 100 to 500 nm, and satisfy following Relational expressions:

25 nmDbDa200 nm(Relational expression 1):

(mass of Ga):(mass of Gb)=5:95 to 30:70(Relational expression 2):