摘要:
An electrophotographic photoreceptor comprising a conductive substrate having thereon an undercoat layer and a photoconductive layer, the undercoat layer comprising a specific polymer compound which is prepared by using at least one of monomers represented by formula (1): ##STR1## wherein R.sup.1 represents a hydrogen atom or a methyl group; and A represents a group represented by formula (2), (3), (4), (5) or (6): ##STR2## where the symbols in the above formulae are defined in the specification.
摘要:
A photosensitive body for electrophotography having improved properties in the charging characteristics, photosensitivity, and stability in repeated use. The photosensitive body for electrophotography comprises a photoconductive layer formed on a conductive support through an undercoat layer, the undercoat layer containing at least one polyester compound having repeated units represented by the following general formula (I): ##STR1## wherein A and B each independently represents a divalent aliphatic hydrocarbon or aromatic hydrocarbon which is optionally substituted, at least one of A and B being selected from the group consisting of specific divalent groups, and n is 10-10,000.
摘要:
A surface-treated inorganic fine particle includes an inorganic fine particle, a hydrophobizing agent deposited on the surface of the inorganic fine particle and an amino group-containing coupling agent deposited on the surface of the inorganic fine particle, wherein the hydrophobizing agent and the amino group-containing coupling agent in a ratio of 1/(0.01 to 0.1) by weight are deposited on the surface of the inorganic fine particle by treating the surface of the inorganic fine particle with the hydrophobizing agent and the amino group-containing coupling agent. An electrophotographic developer contains toner particles and the surface-treated inorganic fine particles.
摘要:
An electrophotographic toner composition comprising (A) toner particles with an average particle diameter of 9 .mu.m or less comprising at least a binder resin and a colorant, and (B) an additive, wherein the additive is a fine metal oxide powder surface coated with at least one agent for imparting hydrophobic property selected from the group consisting of the following formulae (1), (2) and (3):R.sub.1 Si(X).sub.3R.sub.1 R.sub.2 Si(X).sub.2R.sub.1 R.sub.2 R.sub.3 Si(X).sub.1wherein R.sub.1 represents a substituted or unsubstituted alkyl group having a molecular weight of 113 or more, R.sub.2 and R.sub.3 each represents hydrogen, an alkyl group or an allyl group, and X represents chlorine, an alkoxy group or an acetoxy group. The toner composition causes no impaction to a carrier and no adhesion of the toner particles to a photoreceptor, and can form stable, sufficient images for a long time.
摘要:
A novel black toner for color digital copying machine is provided, which comprises a binder resin having dispersed therein toner particles comprising carbon black having an average primary particle diameter of 35 m.mu.m to less than 50 m.mu.m as a colorant in an amount of 2 to 6 parts. In a preferred embodiment, the average primary particle diameter and content of carbon black are determined such that there exist the following relationships (1) and (2) between the image density (ID) of an image developed with toner particles and the developed amount of toner (TMA) and the image density (ID) is in the range represented by the following relationship (3):ID.ltoreq.8/3(TMA)+4/5 (1)ID.gtoreq.5/3(TMA)+1/2 (2)1.2.ltoreq.ID.ltoreq.1.7 (3)wherein TMA represents the amount of toner in mg supplied per unit cm.sup.2 of photoreceptor when an electrostatic latent image corresponding to a solid image is developed; and ID represents a value determined by means of a Macbeth densitometer.
摘要:
A method for fixing a full color toner image by inserting a transfer medium to which a toner image is transferred, between a pair of rolls of a fixing apparatus, and pressing the medium therebetween, wherein the toner image is formed of a full color toner prepared by dispersing a colorant into a polyester resin containing a diol component represented by the following general formula (I) as a constituent and having a softening point of 100.degree. to 120.degree. C., as measured by a ring and ball method, a glass transition temperature of 55.degree. C. or more, a Gardner color scale of 2 or less and a haze value of 15 or less, and the fixing operation is conducted while supplying a functional group-containing organopolysiloxane having a viscosity of 10 to 100,000 cs at 25.degree. C. to a roll in contact with the toner image, whereby the full color toner image can be stably fixed without wrapping of the transfer medium around the roll and offset, and the fixed image having good image quality can be obtained: ##STR1## wherein R represents an ethylene group or a propylene group, each of x and y is an integer of 1 or more, and x+y is 2 to 6.
摘要:
A color toner and a black toner for electrostatic charge development comprises a binder resin and a colorant, wherein the binder resin comprises a polyester resin containing (a) an ethoxylated bisphenol type diol, (b) a propoxylated bisphenol type diol and (c) an aromatic dicarboxylic acid or an anhydride or ester thereof, as main monomer components, and the polyester resin further containing (d) at least one compound selected from the group consisting of alkylsuccinic acids, acid anhydrides and esters thereof, alkenylsuccinic acids, and acid anhydrides and esters thereof in an amount of 7 to 25 mol % based on the total monomer amount of the polyester resin, and the colorant is a flushing pigment comprising hydrous paste of an organic pigment and the polyester resin, or comprising a carbon black having a primary particle size of from not less than 30 nm to not more than 50 nm. Furthermore, a method for producing the color toner and the black toner, and an method for forming a full color image using the color toners or using the color toners and the black toner in combination, are disclosed.
摘要:
A method for forming an image with a copying machine capable of both color copying and black-and-white copying is disclosed, in which a black toner contains at least a colorant and a resinous component having a weight average molecular weight (Mw) of from 25,000 to 80,000 and a number average molecular weight (Mn) of from 2,000 to 8,000, with a Mw/Mn ratio being not less than 10, and having an apparent melt viscosity of 1.times.10.sup.4 poise at a temperature between 115.degree. C. and 140.degree. C. as measured by a flow tester method, and the quantity of heat of fixing is varied between a B/W mode and a color mode.
摘要:
A color toner providing a toner image excellent in brightness, clearness and graininess and a process for producing the same are disclosed, wherein a proportion of dispersed pigment particles having a circle-equivalent diameter of 0.3 .mu.m or greater does not exceed 0.1% of the total number of said dispersed pigment particles. The process comprises kneading a water-containing pigment paste and a binder resin at a temperature of 100.degree. C. or higher under pressure in a heat and pressure kneader to remove a water content to obtain a pigment dispersion, melt-kneading the resulting pigment dispersion together with a binder resin, and grinding the mixture.
摘要:
An image-forming process capable of keeping a high transfer efficiency for a long period of time, reducing the amount of the toner to be recovered and wasted and obtaining stabilized images without causing image quality defects such as density lowering, density unevenness, ghosts, fog, etc., wherein inorganic fine particles contained in a toner transfer from the toner to an electrostatic latent image holder surface and attach thereto, the attached amount of the inorganic fine particles to the electrostatic latent image holder surface is from 1 to 20% as the average occupied area ratio (CAV) in the electrostatic latent image holder surface, and the difference (CMAX−CMIN) of the maximum occupied area ratio and the minimum occupied area ratio of the attached inorganic fine particles in the electrostatic latent image holder surface is not larger than about 5%.