A fine particle of a silicon polymer having a siloxane group and a silanol group, wherein a moisture adsorption amount of the fine particle at a temperature of 30 C. and a humidity of 80% RH is from 1.0 mg/g to 22.0 mg/g, an amount of the silanol group of the fine particle measured by a titration method using KOH is from 0.012 mmol/g to 0.120 mmol/g, and a number average particle diameter of primary particle of the fine particle is from 0.05 m to 0.30 m.

Provided are a toner and a two-component developer each of which: shows a small fluctuation in charge quantity and a small fluctuation in image density even under a high-temperature and high-humidity environment; and does not cause any member contamination even after endurance and hence can stably output an image. The toner and the two-component developer each have a feature in that positively chargeable strontium titanate fine particles are added to toner particles having fixed thereto negatively chargeable silica fine particles.

Herein is disclosed an electrostatic ink composition, wherein the composition is formable by combining: chargeable particles comprising a resin, a charge director comprising a sulfosuccinate salt, and a non-polymeric, non-fatty acid having a pK.sub.a, when measured in water at 20 C., of at least 1. Also disclosed herein is a method of forming an electrostatic ink composition, and a method of electrostatic printing.

The magnetic toner includes magnetic toner particles comprising a binder resin and a magnetic body and inorganic fine particles present on the surface of the magnetic toner particles, wherein the inorganic fine particles present on the surface of the magnetic toner particles comprise metal oxide fine particles, the metal oxide fine particles containing silica fine particles, and optionally containing titania fine particles and alumina fine particles, and a content of the silica fine particles being at least 85 mass % with respect to a total mass of the silica fine particles, the titania fine particles and the alumina fine particles, wherein; when a coverage ratio A (%) is a coverage ratio of the magnetic toner particle's surface by the inorganic fine particles and a coverage ratio B (%) is a coverage ratio of the magnetic toner particles' surface by the inorganic fine particles that are fixed to the magnetic toner particle's surface, the magnetic toner has a coverage ratio A, a coefficient of variation on the coverage ratio A, a ratio of the coverage ratio B to the coverage ratio A, and a compression ratio in a specific range.

Provided is toner comprising toner particle containing binder resin and colorant and silica fine particle, wherein: the silica fine particle contains silica fine particle A and silica fine particle B; silica fine particle A has a number average particle diameter of primary particle of 5 nm or more and 20 nm or less; silica fine particle B has a number average particle diameter of primary particle of 80 nm or more and 200 nm or less; and silica fine particle B has a half width of a peak of primary particle of 25 nm or less, in a weight-based particle size distribution, and wherein when the toner is measured by adhesive force-measuring method by using polycarbonate thin film, an adhesion of the silica fine particle A is 0.5% by area or less relative to 100% by area of the total area of the polycarbonate thin film.

A brilliant toner includes a toner particle that includes a binder resin, a flake-shaped brilliant pigment, and a layered inorganic substance, wherein a content of the layered inorganic substance is from 0.005% by weight to 2.0% by weight with respect to the toner particles, and 80% by weight or more of the layered inorganic substance is present in a portion being in a range of 5 nm to 20 nm from a surface of the toner particle.

Composite materials such as composite particles have a solid non-elastomeric continuous phase made of an organic polymer having a glass transition temperature of at least 25 C. Dispersed within this solid non-elastomeric continuous phase are many multi-compartment porous chemically crosslinked elastomeric particles that have a mode particle size of at least 1 m and up to and including 10 m. The composite particles can be used as toner particles in electrophotographic imaging methods to provide fused toner images and especially stacked fused toner images.

Oxidation resistant crosslinked ultrahigh molecular weight polyethylene (UHMWPE) is described, wherein at least two different additives in the manufacture synergistically increase the oxidation resistance of crosslinked UHMWPE. This allows the manufacture of oxidation resistant crosslinked UHMWPE using lower levels of additives and/or lower levels of crosslinking irradiation or chemicals. The lower levels of additives and/or crosslinking produce crosslinked UHMWPE having desired physical properties not possible without the synergistic interaction of the additives. This crosslinked UHMWPE may be used in medical prostheses such as in bearing components having desired physical properties such as wear resistance and oxidation resistance not possible without the synergistic interaction of the additives.

Disclosed is an electrostatic image developer containing colored resin particles containing a binder resin and a colorant, and an external additive, wherein, as the external additive, the electrostatic image developer contains plate-shaped zinc oxide fine particles having an average longer length of 50 to 2,000 nm and a value S of 0.0001 to 0.03 nm.sup.1, which is a value obtained by dividing an average thickness d of the particles by an average base area A of the particles, and a content of the plate-shaped zinc oxide fine particles is in the range from 0.05 to 1 part by mass, with respect to 100 parts by mass of the colored resin particles.

A toner comprising a toner particle containing an amorphous polyester resin, a crystalline polyester resin and a wax, wherein in a cross-section of the toner by transmission electron microscopy (TEM), domains of the wax and crystals of the crystalline polyester resin are present, the area occupied by the domains of the wax is 0.5% to 8.0% and the area occupied by the crystals of the crystalline polyester resin is 0.5% to 8.0% of the cross-sectional area of the toner, the number-average diameter Dw of the domains of the wax is 60 nm to 240 nm, the aspect ratio of the crystals of the crystalline polyester resin is 5.0 to 25.0, and the number-average diameter Dc of major axis lengths of the crystals of the crystalline polyester resin is 0.8 to 2.0 times the Dw.