Abstract: The master comprises a polyester resin as a binder resin and a carbon black as a colorant having a primary particle size of 10 nm to 100 nm, is blended with 30 to 60 parts by weight of the carbon black, has a lightness L* of 20 or more; and the reflectance A at 400 nm thereof and the reflectance B at 700 nm thereof fall within the range satisfying the relation given by the following formula [1]: 0.5<B/A<5[1] The carbon black in the toner can be made to be present stably in the conditions such that the carbon black has a small primary particle size and is homogeneously dispersed.
Abstract: To provide a black toner having excellent charging property and transferring property against a severe environmental change. The black toner includes toner particle containing at least a binder resin, carbon black and a releasing agent, wherein: the toner particles have a weight-average particle diameter of 3.5 to 8.0 ?m; total amount of acid value and hydroxyl value of the toner is 30 to 75 mgKOH/g; average circularity of particles contained in the toner having circle-equivalent diameter of 2 ?m or more is 0.915 to 0.960; loss tangent tan ? (103 to 104 Hz) of the toner is represented by the following expression: tan ?(103 to 104 Hz)?0.0060 where the loss tangent tan ? is represented by ??/?? where ?? denotes dielectric loss factor and ?? denotes dielectric constant, and tan ? (103 to 104 Hz) denotes the loss tangent in a frequency range of 103 to 104 Hz; and a ratio of tan ? (105 Hz) to tan ? (5×104 Hz) is represented by the following expression: 1.05?tan ?(105 Hz)/tan ?(5×104 Hz)?1.
Abstract: A black toner comprises a binder resin and black composite particles having an average particle diameter of 0.005 to 0.30 ?m, and comprising: extender pigments as core particles; a gluing agent-coating layer formed on surface of the respective core particles; and a black pigment coat uniformly formed on the gluing agent-coating layer in an amount of 1 to 500 parts by weight based on 100 parts by weight of the extender pigments. Such a black toner using black composite particles having not only excellent blackness, fluidity and light resistance, but also an excellent dispersibility in binder resins, which toner also exhibits excellent blackness, fluidity and light resistance.
Abstract: A nonmagentic one-component toner for an electrophotographic image forming apparatus includes a toner with toner particles, a binder resin having a coloring agent, a charging control agent, and a release agent, and an external additive added to the toner particles. The external additive includes approximately 0.1 to 3.0 wt % of silica having a charge opposite to the toner particles, approximately 0.1 to 3.0 wt % of silica having a same charge as the toner particles, and approximately 0.1 to 4.0 wt % of titanium dioxide.
Abstract: A dry toner is provided that is prepared by a method including the steps of (A) dissolving or dispersing a toner composition in an organic solvent to prepare a toner composition liquid and (B) dispersing the toner composition liquid in an aqueous liquid which contains a binder resin formed of a modified polyester (i) and a colorant containing a carbon black having a pH not greater than 7, wherein the toner has a volume average particle diameter (Dv) is from 3 to 7 &mgr;m and a ratio of the volume average particle diameter (Dv) to a number average particle diameter (Dp) is from 1.00 to 1.25.
Abstract: A toner consisting of either a black toner or a color toner for use in an oil-less fixing system free from an oil coating on a fixing roller, the toner comprises a binder resin and a wax as well as carbon black having an oil absorption of 50 to 100 mL/100 g where the toner is the black toner or a coloring agent where the toner is the color toner, and is characterized in that the binder resin has a rate of decrease of storage elastic modulus G′ of not more than 0.3 Pa/° C. as determined in association with temperature increase in the range of 160 to 200° C. The binder resin preferably has a weight average molecular weight [Mw] of 10,000 to 200,000, an [Mw]Mn] ratio between [Mw] and a number average molecular weight [Mn] thereof in the range of 1 to 15, or a peak rate of decrease of the storage elastic modulus G′ in the temperature range of 70 to 100° C.
Abstract: The master comprises a polyester resin as a binder resin and a carbon black as a colorant having a primary particle size of 10 nm to 100 nm, is blended with 30 to 60 parts by weight of the carbon black, has a lightness L* of 20 or more; and the reflectance A at 400 nm thereof and the reflectance B at 700 nm thereof fall within the range satisfying the relation given by the following formula [1]:
Abstract: A black toner comprises a binder resin and black composite particles having an average particle diameter of 0.005 to 0.30 &mgr;m, and comprising: extender pigments as core particles; a gluing agent-coating layer formed on surface of the respective core particles; and a black pigment coat uniformly formed on the gluing agent-coating layer in an amount of 1 to 500 parts by weight based on 100 parts by weight of the extender pigments. Such a black toner using black composite particles having not only excellent blackness, fluidity and light resistance, but also an excellent dispersibility in binder resins, which toner also exhibits excellent blackness, fluidity and light resistance.
Abstract: A toner for development of electrostatic images comprising carbon black as a colorant, wherein the carbon black has the following features:
(1) the primary particle diameter being within a range of 28 to 60 nm;
(2) the DBP oil absorption being within a range of 40 to 75 ml/100 g; and
(3) the pH being within a range of 6.0 to 10.0, and a production process of the toner by a suspension polymerization process.