摘要:
Toner is for use in an image forming apparatus of the TonerJet method, which satisfies any one of the following conditions: a) toner in which the content of reverse-polarity large-diameter toner is 10% by count or smaller; b) toner in which the content of reverse-polarity fine-powder toner is 2% by count or smaller; c) toner comprising a silica additive and a titanium oxide additive such that the content x of the titanium oxide additive is in the range of 0
摘要:
The surface of a photoconductor is coated with a surface protection layer comprising a cured material of a fluorine-containing photo-curing composition containing fluorinated alkyl group-containing (meth)acrylate and a photopolymerization initiator, and the surface protection layer has a fluorine atom content of 8.5 to 20% by mass.
摘要:
A non-magnetic single-component toner 8 of the present invention has toner mother particles 8a, and external additives 12 comprising: two hydrophobic silicas 13, 14 of which particle diameters are different from each other, i.e. a mean primary particle diameter of 7 nm to 12 nm and a mean primary particle diameter of 40 nm to 50 nm, and a hydrophobic rutile/anatase type titanium oxide 15 having a spindle shape of which major axial diameter is in a range from 0.02 nm to 0.10 nm and the ratio of the major axial diameter to the minor axial diameter is set to be 2 to 8, wherein the external additives 12 adhere to the toner mother particles 8a. By the hydrophobic silicas 13, 14 having work function smaller than the work function of the toner mother particles 8a, the negative charging property is imparted to the toner mother particles 8a and the fluidity is also insured. On the other hand, by mixing and using hydrophobic rutile/anatase type titanium oxide particles 15 having work function larger than or equal to the work function of the toner mother particles 8a together with the hydrophobic silicas 13, 14, the non-magnetic single-component toner 8 is prevented from excessively charged. Therefore, the amount of fog toner on non-image portions is reduced, the transfer efficiency is further improved, the charging property is further stabilized, and the production of reverse transfer toner is further inhibited.
摘要:
The present invention provides a toner having: a toner mother particle; a first external additive including a first inorganic fine particle having a primary particle size distribution of 200 to 750 nm and a work function approximately equivalent to that of the toner mother particle; a second external additive including a second inorganic fine particle having an mean particle size smaller than that of the first inorganic fine particle and a work function smaller than that of the toner particle, a stirring member of a developing device and/or an inner wall of the developing device; and 0.01% to 0.3% by weight of a metal soap having a work function approximately equivalent to that of the toner mother particle.
摘要:
A two-component electrophotographic developer for use in developing a latent electrostatic image of a low potential. The developer is composed of a mixture of a magnetic carrier of spherical sintered ferrite particles having raised and depressed portions attributed to the primary particles on their surface, a median size of from 30 to 50 micrometers, an apparent density of less than 2.6 g/cc and an electric resistance, measured in the form of a magnetic brush, of from 6.times.10.sup.4 to 2.5.times.10.sup.6 ohms and chargeable toner particles having a volume inherent resistivity of at least 1.times.10.sup.13 ohms-cm and a specific inductive capacity of from 4 to 6. In a preferred embodiment, the chargeable toner particles have a median size of from 10 to 14 micrometers and are substantially free from particles having a particle diameter of not more than 5 micrometers. The developer can give an image of a high density, a high resolution and excellent gradation without brush marks.
摘要:
A photosensitive material for electrophotography, which comprises an electroconductive substrate and a photosensitive layer formed on the substrate. The photosensitive layer comprising a charge transfer medium and a charge-generating pigment dispersed in the mediums. The photosensitive layer contains as the matrix resin a thermoplastic polyester consisting essentially of recurring units represented by the following general formula: ##STR1## wherein R.sup.1 stands for a phenylene group or an ethylene group, R.sup.2 stands for a group represented by the formula ##STR2## R.sup.3 stands for a direct bond or a divalent bridging atom or group, and the ring A may have a substituent not participating in the reaction.In another embodiment a photosensitive material for electrophotography includes an electroconductive substrate, a photoconductive organic pigment-containing, charge-generating layer formed on the substrate and a charge transfer layer formed on the charge-generating layer, wherein the charge transfer layer contains as the matrix resin the above-mentioned thermoplastic polyester. These thermoplastic polyesters provide improvements in adhesion to the substrate, surface hardness and abrasion resistance.
摘要:
Disclosed is a one-component type magnetic developer consisting essentially of a particulate shaped article of a composition comprising a binder resin medium and a powdery magnetic material dispersed in the binder resin medium, wherein said magnetic material comprising (A) a non-pulverizing agglomerate of cubic particles of magnetite having a particle size of 1 to 10 .mu.m as measured by an electron microscope and (B) magnetite particles having a particle size of 0.2 to 1 .mu.m at an (A)/(B) weight ratio of from 95/5 to 10/90, especially from 95/5 to 30/70.
摘要:
Disclosed is a heat-sensitive recording material capable of forming an image of a hue close to a pure black at a low density, which comprises a dispersion of a leuco dye, a heat-fusible organic acidic substance solid at normal temperature and a sensitizing agent in a binder, wherein the leuco dye comprises a fluoran type leuco dye for forming a black color and a benzofluoran type leuco dye for forming a red dye in an amount of 0.01 to 1% by weight based on said black color-forming leuco dye.
摘要:
In the electrostatic recording process comprising relatively scanning a recording electrode on an electrostatic recording material electrically connected between said recording electrode and a counter electrode, applying a high frequency alternating current or asymmetric alternating current recording signal formed by amplifying and modulating an image signal by a high frequency carrier wave between said two electrodes to form an electrostatic image on the electrostatic recording material, developing the so formed electrostatic image with a developer and, if desired, fixing the developed image, when an electrostatic recording material including an electroconductive substrate having a specific multi-layer distribution structure is used and if a dielectric layer is disposed on this electroconductive substrate in a specific arrangement selected according to the kind of the recording signal to be applied, such problems as blurring, tailing and fogging can be effectively eliminated and recorded images excellent in the density and sharpness can be obtained without substantial influences of the humidity in the recording atmosphere.
摘要:
A color image forming apparatus includes, for each of liquid developers of plural colors, a photosensitive member, a developing roller, an agitating device that agitates a liquid developer having a viscosity characteristic dependent on a shearing force, and a developer supplying unit that supplies the liquid developer to the developing roller. In development, agitation start timing is varied depending on the color of the liquid developer.