A toner melt-kneading apparatus to perform melt-kneading includes a kneading chamber, a discharge member connected to the kneading chamber, and a pressure gauge provided to the discharge member. The discharge member includes a flow passage having a substantially cylindrical shape and configured to pass a kneaded material. The pressure gauge includes a thermometer and includes a pressure-measuring portion disposed in the flow passage. D, d, and ϕ satisfy the following relationship, where a length of the flow passage is denoted as D, a distance from a discharge port in a downstream-side end portion of the discharge member to the pressure-measuring portion is denoted as d, and an inner diameter of the flow passage is denoted as ϕ, 0.020≤(d/D)/ϕ (herein, D>d).

The present disclosure provides a toner excellent in low-temperature fixability and excellent in durability under harsh environments of high-temperature and high-humidity, and a method for producing the toner. The toner can contain: a toner particle containing a binder resin, wax, and an inorganic oxide particle; and an external additive, wherein the inorganic oxide particle contains, as a main component, an oxide of at least one element selected from the group consisting of Si, Mg, Al, Ti, and Sr; when a thin piece obtained by cutting the toner with a microtome is observed with a transmission electron microscope (TEM), the major axis A of the inorganic oxide particle is 0.10 to 3.00 μm; and in a wettability test of the toner with respect to a methanol/water mixed solvent, a methanol concentration at a transmittance of light having a wavelength of 780 nm of 50% is 5.0 to 30.0% by volume.

The present invention provides a toner including a toner particle containing a binder resin and a release agent. The binder resin contains an amorphous resin and a crystalline resin, and a content of the crystalline resin is 1.0% to 20.0% by mass based on a mass of the binder resin. In a cross-section of the toner particle observed by scanning transmission electron microscopy, (i) there exist a matrix A of the amorphous resin and domains A of the release agent dispersed in the matrix A, (ii) the domains A each include a matrix B of the release agent and domains B of the crystalline resin dispersed in the matrix B, and (iii) the domains A are each covered with the crystalline resin and an average coverage of the domains A by the crystalline resin is 70% or more.

A two component developer comprising a toner and a specific magnetic carrier, wherein a toner particle in the toner comprises a surface layer comprising an organosilicon polymer, electrical conductivity of a filtrate obtained by filtering off the toner using a specific procedure is 1.0 to 2.5 μS/cm, and when dC (atomic %) denotes carbon concentration, dO (atomic %) denotes oxygen concentration and dSi (atomic %) denotes silicon concentration, as measured by ESCA, at the surface of the toner particle, then the dC, the dO and the dSi satisfy the following formulae:

40.0≤dC/(dC+dO+dSi)×100≤60.0

10.0≤dSi/(dC+dO+dSi)×100≤26.0.

A carrier for electrostatic image development includes: a core material; and a coating resin layer that contains inorganic particles and covers the core material. The content of the inorganic particles is 10% by mass or more and 60% by mass or less based on the total mass of the coating resin layer. The volume average diameter D (μm) of the inorganic particles and the thickness T (μm) of the coating resin layer satisfy the following relational expression (1): 0.007≤D/T≤0.24.

An emulsion aggregation toner including a toner particle comprising at least one resin; an optional colorant; an optional wax; and a charge control agent disposed on a surface of the toner particle; the charge control agent comprising a complex formed from a metal ion donor and at least one of a ligand selected from a member of the group consisting of a polyaromatic acid comprising humic acid, a pyranone based ligand, a furanone based ligand, or a combination thereof.

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.

[Summary] To provide resin particles with high weather resistance even when a plant-derived resin and PET are used as binder resins.

[Tasks] The Resin particles includes a binder resin and a colorant, wherein the binder resin contains polyethylene terephthalate and a plant-derived resin, wherein the colorant contains an isoindoline pigment, and wherein a radioisotope .sup.14C concentration in the resin particles is 5.4 pMC or higher.

Resin particles are provided. The resin particles include one or more binder resins, a release agent, and a colorant. The one or more binder resins include an amorphous resin. The amorphous resin contains an alcohol component as one of the constituents thereof. The alcohol component includes a plant-derived alcohol component. The resin particles contain a tetrahydrofuran (THF)-insoluble component by an amount of from 5% by mass through 40% by mass.

The present invention relates to a toner for development of electrostatic images which contains a colorant, a resin composition (P) and an ester composition (C), in which the resin composition (P) is a resin composition formed by subjecting an acid group-containing amorphous polyester-based resin (A) and an amine compound to condensation reaction, and the ester composition (C) is at least one composition selected from the group consisting of the following ester composition (CI) and ester composition (CII); and a process for producing the toner.