An external additive for toner comprising a particle of a silicon polymer having a siloxane bond and a SiR.sup.1 bond, wherein the R.sup.1 represents an alkyl group having from 1 to 6 carbon atoms, in a chart obtained by .sup.29SiNMR measurement of the external additive, where a total peak area attributed to the external additive is denoted by A, and a peak area attributed to the SiR.sup.1 bond is denoted by B, a following formula (1) is satisfied, and in the chart obtained by .sup.29SiNMR measurement of the external additive, where a total peak area attributed to the silicon polymer is denoted by SA, and a peak area attributed to a T unit structure is denoted by S3, a following formula (2) is satisfied; $\begin{array}{cc}0.260B/A0\text{.450}& \left(1\right)\end{array}$$\begin{array}{cc}0.S3/\mathrm{SA}0\text{.50}.& \left(2\right)\end{array}$

A toner comprising a toner particle comprising a binder resin, and an external additive, wherein the external additive comprises a fatty acid metal salt particle; the toner comprises fumaric acid; with a (mol/g) as a content of the fumaric acid in the toner, and with b (mol/g) as a content of the fatty acid metal salt particle in the toner, Formula (1) below is satisfied:

[00001]$\begin{array}{cc}0.50?a/b?70\text{.00}.& \left(1\right)\end{array}$

A toner comprising a toner particle comprising a binder resin, and an external additive, wherein the external additive comprises a hydrotalcite particle, the toner comprises fumaric acid, and when a content of the hydrotalcite particle in the toner on a mass basis is denoted by a (%) and a content of the fumaric acid in the toner on a mass basis is denoted by b (%), then the a and the b satisfy formula (1) below:

[00001]$\begin{array}{cc}1.a/b300..& \left(1\right)\end{array}$

Provided is an electrophotographic member that includes a surface with excellent abrasion resistance and allows toner to have an increased charge amount, thereby eliciting uniform and high transfer efficiency. This electrophotographic member is provided with a surface layer including at least one of an acrylic resin and methacrylic resin, the surface layer further including a positively chargeable charge control agent, wherein a surface of the surface layer is free from a convex portion having a height of more than 15 m resulting from the charge control agent.

Provided is an electrophotographic member that includes a surface with excellent abrasion resistance and allows toner to have an increased charge amount, thereby eliciting uniform and high transfer efficiency. This electrophotographic member is provided with a surface layer including at least one of an acrylic resin and methacrylic resin, the surface layer further including a positively chargeable charge control agent, wherein a surface of the surface layer is free from a convex portion having a height of more than 15 m resulting from the charge control agent.

A part material for printing three-dimensional parts with an electrophotography-based additive manufacturing system, the part material including a composition having a copolymer (including acrylonitrile units, butadiene units, and aromatic units), a charge control agent, and a heat absorber. The part material is provided in a powder form having a controlled particle size, and is configured for use in the electrophotography-based additive manufacturing system having a layer transfusion assembly for printing the three-dimensional parts in a layer-by-layer manner.

The present invention relates to a toner for electrostatic charge image development, including toner base particles containing a binder resin containing as a main component a vinyl resin having a constitutional unit derived from a monomer having an acid group, and aluminum, wherein a concentration of the aluminum in the toner base particles, as measured by radio inductively coupled plasma emission spectral analysis, is from 900 to 2,200 ppm. According to the present invention, there is provided a means for improving the environmental stability of electrification, and the glossiness and the image density of the image to be formed in a good balance while maintaining sufficient low temperature fixability in a toner for electrostatic charge image development.

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):

The present invention is to provide a toner for developing electrostatic images, which is configured to have excellent low-temperature fixability, resistance to filming, inhibition of fog in a high temperature and high humidity environment, and excellent printing durability in a high temperature and high humidity environment (resistance to fog under load of continuous printing). Disclosed is a toner for developing electrostatic images, including colored resin particles containing a binder resin and a colorant, and external additives, wherein, as the external additives, the toner contains the specific amount of the zinc oxide fine particles having the specific particle diameter and the specific amount of the alumina fine particles having the specific particle diameter.

Herein is disclosed an electrostatic ink composition, wherein the composition is formable by combining: chargeable particles comprising a resin comprising a polymer having acidic side groups, and a cyclic anhydride. Also disclosed herein is a method of forming an electrostatic ink composition, and a method of electrostatic printing.