Abstract: The present invention provides an electrophotographic toner containing, as a fixing resin, a styrene-acrylic copolymer in which styrene content, molecular-weight distribution and acid value are specified. The electrophotographic toner of the present invention is improved in heat resistance by raising the glass transition temperature of the fixing resin, while assuring excellent low-temperature fixing properties and resistance to off-set.

Abstract: A carrier for developing electrostatic latent images is disclosed, which comprises a core material at least a part of which is coated with a resin containing a copolymer comprised of vinylidene chloride and at least one monomer having an unsaturated double bond and being copolymerizable with vinylidene chloride, wherein the copolymer is comprised of (a) from 70 to 30 mol % of vinylidene chloride, (b) from 20 to 60 mol % of acrylonitrile and/or an acrylonitrile derivative, and (c) from 0 to 40 mol % of a monomer having an unsaturated double bond and being copolymerizable with components (a) and (b). An electrophotographic developer containing the carrier and an electrophotographic developing process using the developer are also disclosed.

Abstract: This invention is directed to dry, negatively charged toner compositions and developer compositions, the toner composition being comprised of resin particles prepared from a polyester having a glass transition temperature of 50.degree. to 100.degree. C. and a weight average molecular weight of 20,000 to 100,000 and from about 0.1 to about 10 percent by weight based on the weight of the resin particles of a mixture of ortho-benzoic sulfimide as represented by the formula: ##STR1## and para-anisic acid as represented by the formula: ##STR2## in a weight ratio of 1:1 as a charge-controlling additive.

Abstract: A color toner is constituted to form a polyester binder resin and a colorant. The polyester resin is obtained from a monomer mixture including, at least: 25-35 mol. % of a dibasic aromatic acid component (a) selected from isophthalic acid, terephthalic acid and derivatives thereof; 2-4 mol. % of a tribasic aromatic acid component (b) selected from trimellitic acid and derivatives thereof; 12-18 mol. % of a dibasic acid component (c) selected from dodecenylsuccinic acid, octylsuccinic acid, and anhydrides thereof; and 45-60 mol. % of an etherified diphenol component (d) obtained by propoxidation or/and epoxidation, each percentage being based on a total of the monomers. The polyester resin is characterized by having a hydroxyl value of 10-20, a weight-average molecular weight (Mw) of 13,000-20,000, a number-average molecular weight (Mn) of 5,000-8,000, and an Mw/Mn ratio of 2-3.5.

Abstract: A homogeneous liquid composition, for use in the preparation of liquid toners containing at least one charge director and in which the electrical properties of the charge director(s) is/are stabilized, comprises: (1) insulating non-polar carrier liquid compatible with liquid toners for electrostatic imaging; (2) at least one charge director other than an amine salt; and (3) at least one stabilizing component in an amount effective to stabilize the electrical properties of said at least one charge director, said component being selected from non-quaternary amine salts and being soluble in the carrier, e.g. diethylammonium chloride and isopropylamine dodecylbenzenesulfonate. The invention further relates to liquid toners for electrostatic imaging comprise thermoplastic resin particles dispersed in an insulating non polar carrier liquid, preferably a hydrocarbon having a volume resistivity above 10.sup.9 ohm-cm and a dielectric constant below 3.

Abstract: A toner composition of resin, pigment, wax, and a component of the formula ##STR1## wherein n is a number of from about 30 to about 50 and m is a number of from about 3 to about 16.

Abstract: The present invention provides silicone resin-coated carrier particles used in two-component dry-process developers for electrophotographic processes. The present invention also provides a method for preparing carrier particles using a mixture of two silicone resin compositions.

Abstract: A toner resin composition comprising 5 to 40% by weight of a polyester (A) having a weight average molecular weight of 3,000 to 20,000 and 50 to 95% by weight of a styrene-acrylic copolymer (B). The styrene-acrylic copolymer (B) is comprised of 10 to 25% by weight of a high molecular weight polymer (B1) having a weight average molecular weight of 500,000 to 1,100,000 and 75 to 90% by weight of a low molecular weight polymer (B2) having a weight average molecular weight of 5,000 to 100,000. The high molecular weight polymer (B1) is comprised of a styrene component (b-1) and an acrylic ester and/or methacrylic ester component (b-2). The low molecular weight polymer (B2) is comprised of a styrene component (b-1), an acrylic ester and/or methacrylic ester component (b-2), 0.3 to 3 parts by weight, per 100 parts of the total weight of said component (b-1) and component (b-2), of an .alpha.-methyl styrene dimer (b-3) and 0.

Abstract: A continuous method of treating a polymer reaction mixture for continuously separating a styrene polymer and volatile ingredient by flowing down, for example, a mixture of low molecular weight styrene polisher and high molecular weight styrene polymer through a circular-ring-shaped space formed between a jacketed double pipe and a concentrically located inner pipe of a heat-exchanger, and flashing into a vacuum chamber connected with said heat-exchanger, is provided.The polymer is useful for the preparation of electrophotographic toner.

Abstract: A toner for electrophotography which comprises, as a binder resin, a polyester resin obtained from carboxylic acids containing aromatic monomer in a proportion of 80 mol % or more relative to the entire carboxylic acid component, and alcohols containing aliphatic diols having 2 to 4 carbon atoms in a proportion of 70-100 mol % relative to the entire alcohol component and alicyclic alcohols in a proportion of 0-30 mol % relative to the entire alcohol component, and having a specific gravity of 1.3 or more, a glass transition temperature of 58.degree. C. or more, and a number average molecular weight of 1,000-6,000. The toner of the present invention is superior in image characteristics, fixability, storage stability (resistance to blocking), resistance to plasticizer and charge stability.

Abstract: A toner for developing an electrostatic image, comprises a binder resin and a colorant. Such binder resin contains a THF-insoluble component in an amount of less than 10 wt. % based on the binder resin, and, in the molecular weight distribution measured by GPC (gel permeation chromatography) of a THF-soluble component, has a weight average molecular weight/number average molecular weight (Mw/Mn) of .gtoreq.18, a molecular weight peak MA in the region of a molecular weight of from 3,000 to 20,000, a molecular weight peak MB in the region of a molecular weight of from 380,000 to 1,000,000, a molecular weight minimum Md in the region of a molecular weight of from 20,000 to 380,000, provided that MB/MA is in the range of from 30 to 150, and a molecular weight distribution curve area ratio SA:SB:Sd of 1:0.3 to 0.8:0.35 to 0.8.

Abstract: A decorative sheet having a first substrate sheet 11 formed of a transparent plastic material, in one or both of the surfaces of which all or a part of a pattern-printed layer 2 is embedded, a laminated sheet formed by laminating a second substrate sheet 12 formed of a transparent plastic material on one surface of the abovementioned sheet, or a laminated sheet formed by laminating a third substrate sheet, 13 formed of a plastic material having a concealing effect on the above-mentioned sheet or laminated sheet. This decorative sheet has an excellent three-dimensional effect.

Abstract: A toner powder for the development of latent electrostatic or magnetic images, the toner powder containing a polyester resin based on an etherified diphenol and a dicarboxylic acid mixed with a reaction product of an epoxy resin and a phenol compound or a carboxylic acid, and the process for forming fixed images on an image receiving material utilizing the above toner powder, the surface of an intermediate medium consisting of material having a lower affinity for the softened toner powder than does the image receiving material and the toner powder being softened by heating before and/or during transit through a pressure zone.

Abstract: A toner composition comprised of resin particles and pigment particles, and wherein the toner is surface treated with a halogen.

Abstract: The present invention provides an electrophotographic toner composition comprising a binder and a colorant. At least 70 wt. % of the binder are soluble in THF, the number average molecular weight (Mn) and Z average molecular weight (Mz) of the THF-soluble portion of the binder as measured using THF are 2,000-15,000 and at least 400,000, respectively. The particle size of the binder has been controlled so that D.sub.75 is not greater than 2.5 mm, D.sub.25 not smaller than 0.15 mm and D.sub.75 /D.sub.25 at least 1.5. The toner composition does not have variations from one lot to another. The quantity of electricity to be charged during a copying operation changes little. The picture quality can be maintained constant even during a long-time copying operation.

Abstract: In an electrophotographic toner, by using as the binder resin a styrene/acrylic resin in which in the gel permeation chromatogram, a high molecular weight peak value appears in a molecular weight region higher than 1.times.10.sup.5, a low molecular weight peak value appears in a molecular weight region of from 2.times.10.sup.4 to 500, a minimum value appears halfways between the two peaks and the ratio (V/P) of the area of the valley to the peak area is lower than 0.3, the internal cohesive force of the binder resin for the toner can be prominently improved while maintaining the low-temperature fixing property and offset resistance at high levels, and pulverization of the toner and formation of the spent toner can be prevented during the developing operation and the durability of the toner can be improved.

Abstract: A toner for developing statically charged images, comprising a binder resin, a colorant and a charge-controlling dye and a process for the preparation of this toner are disclosed. This toner consisting of particles composed of these components have a circularity of from 0.95 to 1.0, and the concentration of the dye on the surfaces of the toner particles is from 1.0.times.10.sup.-3 to 4.times.10.sup.-3 g/g. By dint of these characteristic features, the stability of the frictional chargeability characteristics of the toner is increased, and the contamination of a carrier, a developing device or the like with the dye can be prevented.

Abstract: Herein disclosed is a binder for dry toners which comprises a copolymer resin obtained by reacting 10 to 50% by weight of a polyester resin which has free carboxyl groups, whose acid value ranges from 10 to 100 and whose number-average molecular weight ranges from 1,000 to 5,000 and 90 to 50% by weight of a mixture of a vinyl compound having a glycidyl group and the an another vinyl compound, wherein the amount of the vinyl compound having a glycidyl group corresponds to the number of the glycidyl groups equal to 0.25 to 1.5 time that of the carboxyl groups present in the polyester resin. The binder for dry toners is used in the electrophotography technique.

Abstract: The present invention provides an electrophotographic toner containing, as a fixing resin, a styrene-acrylic copolymer in which styrene content and molecular-weight distribution are specified, and which contains a specific high-molecular-weight component.The electrophotographic toner of the present invention is improved in bending resistance while assuring excellent low-temperature fixing properties, resistance to off-set and heat resistance.

Abstract: Releasing compositions, comprising at least one polyolefinic resin selected from the group consisting of[1] a polypropylene resin having a melt viscosity of at most 1000 cps at 160.degree. C. and having an isotactic content of at least 90%,[2] an organo silane-modified polyolefin resin, and[3] an organo fluorine-modified polyolefin resin,are suitable for use in electrophotographic toners and are capable of providing high hot offset temperature without reducing flowability of toners.

Abstract: The present invention provides an electrophotographic developer comprising (i) a toner containing, as a fixing resin, a styrene-acrylic copolymer presenting a gel permeation chromatogram showing a molecular-weight distribution in which the detection-starting molecular weight and the detection-ending molecular weight are respectively located in specific ranges, and (ii) a carrier coated with a coating resin which is a styrene-acrylic copolymer containing at least 2-hydroxyethyl acrylate.Even though repeatedly agitated in the developing device, the electrophotographic developer of the present invention is not deteriorated and assures good durability and long life-time.

Abstract: Disclosed herein is an electrophotographic toner composition produced by using a low-melt-viscosity and high-strength resin. The present invention provides a toner which fixes at low heat and has high strength and therefore, is suitable for high-speed copying machines and lower-heat copying machines. The resultant benefits of the present invention are that the lowest limit of the fixing temperature is low, non-offset range is wide and picture properties are good. The electrophotographic toner composition can, therefore, provide stable pictures even when fixed at low heat.

Abstract: A toner for developing an electrostatic image, comprising color resin particles and a particulate additive. The color resin particles contain at least a coloring agent and a binding resin. The color resin particles possess irregular surfaces but not breaks, and the irregularity may be formed by depositing and fixing onto the surface fine resin particles having an average particle size in a range of 1/200 to 1/10 of the color resin particle size. A particulate additive has an average particles size of not more than 1/10 of volume average particle size of the color resin particles. The BET specific surface area of the toner changes by 20% or less before and after the forced stirring of the toner.

Abstract: A toner for developing an electrostatic image, comprises a binder resin and a colorant. The toner has a glass transition temperature (Tg) of 65.degree. C. or lower. The binder resin comprises a styrene-acrylic copolymer formed from at least a styrenic monomer and a mixture of two or more acrylic monomers. The binder resin contains 10% by weight or more of THF insolubles. The amount of the styrenic monomer remaining in the toner is 0.005 part or less by weight based on 100 parts by weight of the binder resin component in the toner (50 ppm), and the amount of the acrylic monomers remaining in said toner is 0.001 part by weight based on 100 parts by weight or less of the binder resin component in the toner (10 ppm). At least one component of the mixture of acrylic monomers has a Q-value of 0.5 to less than 1.0 and the other has a Q-value of 0.3 to less than 0.5.This toner is excellent in the anti-off-set property to a fixing roller surface, good in fixability, giving high image density and little odor.

Abstract: Magnetic carrier for use in electrophotographic development takes the form of ferrite core particles each having a resinous coating. Ferrite core particles having a limited particle size distribution are coated with a resinous composition based on a copolymer consisting essentially of ethyl methacrylate, 15 to 25% by weight of styrene, up to 2% by weight of dodecyl methacrylate, and up to 2% by weight of 2-hydroxyethyl acrylate. The magnetic carrier particles have a resistance of 8.5.times.10.sup.7 to 2.2.times.10.sup.9 .OMEGA.. This carrier has a sharp distribution of electric charge and a quick rise of charging performance. The coating is tough enough to impart durability to the carrier.

Abstract: Electrostatic liquid developer consisting essentially of(A) nonpolar liquid having Kauri-butanol value less than 30, present in major amount,(B) particles, average by area particle size of less than 10 .mu.m, of a degradable polymeric resin as defined, and(C) nonpolar liquid soluble ionic or zwitterionic charge director compound.Optionally a colorant and an adjuvant compound are present. Process of preparation of electrostatic liquid developers is described. The developer is useful in copying, making proofs including digital color proofs, lithographic printing plates, and resists. The developer particles can be readily removed from the printed material, such as paper, by degradation of the polymer. If the polymeric resin is depolymerized, the monomer and low molecular weight units can be recycled by being repolymerized, or discarded in a landfill as a biodegradable environmentally benign by-product.

Abstract: A laminated folding indicia carrier, such as a folding map, consisting of a plurality of laminated rectangular relatively stiff panels, preferably six, wherein an indicia carrier, such as a paper map, is laminated between transparent film. Selected adjacent panels are hingedly connected and pivotal through substantially 360.degree. whereby lateral panels may be selectively folded over either the front or rear face of an associated central panel, and the central panels are hingedly connected for folding over either face of the other central panel. In this manner, any of the identically dimensioned panels may be easily folded as to be visually observed while the folded configuration will be of a single panel size.

Abstract: A toner composition for electrophotography comprises, as a principal component, a reaction product of a mixture which comprises 20 to 80% by weight of a polyester resin (A) whose number average molecular weight ranges from 1,000 to 5,000, whose glass transition point ranges from 0.degree. to 50.degree. C. , whose OH value ranges from 20 to 60 KOHmg/g and which is prepared by using at least one trifunctional alcohol in an amount of from 2 to 10 mole % on the basis of the total amount of starting raw alcohols consisting of at least one diol and at least one trifunctional alcohol; and 80 to 20% by weight of a polyester resin (B) whose number average molecular weight ranges from 1,000 to 5,000, whose glass transition point ranges from 50.degree. to 90.degree. C. and whose OH value is not more than 5 KOH mg/g, with a diisocyanate.

Abstract: This invention provides a fluorine-containing copolymer comprising:(a) 50 to 85 mole % of a structural unit represented by the formula--CH.sub.2 --CF.sub.2--,(b) 5 to 40 mole % of a structural unit represented by the formula--CF.sub.

Abstract: Toner and developer compositions incorporating nonpolymeric, homogeneous, amorphous mixtures of compounds as the binder are described. The mixtures comprise at least two nonpolymeric, thermoplastic organic compounds each having at least two linking components joining one multivalent organic nucleus with at least two organic appended groups wherein either the multivalent organic nucleus or at least one of the appended groups in an aromatic group. The mixtures have glass transition temperatures of 50.degree. to 120.degree. C. Methods for developing electrostatic images with the developer compositions are also described.

Abstract: An electrophotographic dry developer which comprises a carrier and toner particles comprising a binder resin comprising (A) a polyester resin and (B) a styrene-acrylic resin obtained by co-polymerizing a monomer having an amino group, at a weight ratio of (A) to (B) ranging from 55:45 to 95:5, both resin (A) and resin (B) and a dyestuff or pigment of chromatic color. It is positively charageable and serves for color electrophotography.

Abstract: A liquid developer comprises an aliphatic hydrocarbon carrier liquid and a toner dispersed in the carrier liquid, which toner comprises a coloring agent and a resin component, wherein a solid toner component which is obtained by evaporating the liquid developer to dryness has a softening point of 60.degree. C. to 90.degree. C. and flow-initiating point of 110.degree. C. to 160.degree. C.

Abstract: A dispersion polymerization process for the preparation of styrene butadiene polymers with an average particle diameter of from about 0.1 to about 200 microns, which comprises (1) formation of a homogenous reaction medium, containing styrene and butadiene monomers in the presence of a steric stabilizer and a chain propagating amount of an initiator; and (2) heating said homogeneous reaction medium under pressure permitting polymerization thereby resulting in the formation of insoluble styrene butadiene polymer particles.

Abstract: The present invention relates to a polymer composition comprising a high molecular weight polyester having a glass transition temperature of 50.degree. to 100.degree. C. and a weight average molecular weight of 30,000 to 100,000 and a low molecular weight polyester in linear, amorphous form defined by the formula: ##STR1## said low molecular weight polyester having a glass transition temperature of 55.degree.-65.degree. C., wherein:R is a hydrocarbon radical having 2 to 5 carbons andm is a number which gives the low molecular weight polyester a number average molecular weight of 500 to 2000.

Abstract: A low fusing temperature toner powder with good keep and broad fusing latitude characteristics is provided. The toner powder is comprised of polymer particles of a partially carboxylated crystalline polyester and partially carboxylated amorphous polyester that has been crosslinked together at elevated temperature with the aid of an epoxy novolac resin and a crosslinking catalyst.

Abstract: A toner for developing an electrostatic image, comprises a binder resin and a colorant. Such binder resin contains a THF-insoluble matter in an amount of less than 10 wt. % based on the binder resin, and, in the molecular weight distribution measured by GPC (gel permeation chromatography) of a THF-soluble matter, has a weight average molecular weight/number average molecular weight (Mw/Mn) of .gtoreq.18, a molecular weight peak MA in the region of a molecular weight of from 3,000 to 20,000, a molecular weight peak MB in the region of a molecular weight of from 380,000 to 1,000,000, a molecular weight minimum Md in the region of a molecular weight of from 20,000 to 380,000, provided that MB/MA is in the range of from 30 to 150, and a molecular weight distribution curve area ratio SA:SB:Sd of 1:0.3 to 0.8:0.35 to 0.8.

Abstract: A toner for developing static charge images is disclosed which comprises 1 to 15 parts by weight of waxes whose DSC heat absorption regions exist only at a temperature no lower than 50.degree. C. and 100 parts by weight of a binder resin. As for such waxes, there can be used waxes which have been purified by removing fatty acids whose DSC heat absorption regions exist at temperatures no higher than 50.degree. C.

Abstract: A toner composition comprised of pigment particles and a branched polyalkyl/styrene/butadiene copolymer of the following formula ##STR1## wherein m, n and o are weight fraction numbers, p represents the number of CH.sub.2 groups, R is hydrogen or alkyl, and R' is carbonyloxy or aryl.

Abstract: A liquid developer for electrostatic photography is disclosed. The liquid developer comprises at least resin grains dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 .OMEGA.cm and a dielectric constant of not higher than 3.5, wherein the dispersed resin grains are polymer resin grains obtained by polymerizing a solution containing (1) at least a mono-functional monomer (A) which is soluble in the aforesaid non-aqueous solvent but becomes insoluble therein by being polymerized in the presence of a dispersion-stabilizing resin (BA) soluble in the non-aqueous solvent, which is a polymer containing a recurring unit represented by the formula (I) described in the specification, at least a part of the main chain of the polymer being crosslinked, and, optionally, (2) a monomer (B-1) represented by the formula (II-1) described in the specification.

Abstract: A liquid developer for electrostatic photography is disclosed. The liquid developer comprises resin grains dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 .OMEGA. cm and a dielectric constant of not higher than 3.5, wherein the dispersed resin grains are polymer resin grains obtained by polymerizing a solution containing at least one kind of a mono-functional monomer (A) which is soluble in the non-aqueous solvent but becomes insoluble in the non-aqueous solvent by being polymerized, in the presence of a dispersion-stabilizing resin which is soluble in the non-aqueous solvent and is a comb-like copolymer comprising (1) at least a mono-functional macromonomer (M) having a weight average molecular weight of from 1.times.10.sup.3 to 2.times.10.sup.4 and (2) at least a monomer represented by formula (III) as defined in the specification.

Abstract: A liquid developer for electrostatic photography is disclosed. The liquid developer comprises resin grains dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 .OMEGA. cm and a dielectric constant of not higher than 3.5, wherein the dispersed resin grains asre copolymer resin grains obtained by polymerizing a solution containing at least one kind of a mono-functional monomer (A) which is soluble in the non-aqueous solvent but becomes insoluble in the non-aqueous solvent by being polymerized, in the presence of a dispersion-stabilizing resin which is soluble in the non-aqueous solvent and is a comb-like copolymer comprising at least (1) a mono-functional macromonomer (M) having a weight average molecular weight of from 1.times.10.sup.3 to 2.times.10.sup.

Abstract: A liquid developer for electrostatic photography is disclosed. The liquid developer of this invention comprises resin grains dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 .OMEGA.cm and a dielectric constant of not higher than 3.5, wherein the dispersed resin grains are copolymer resin grains obtained by polymerizing a solution containing at least one mono-functional monomer (A) which is soluble in the above non-aqueous solvent but becomes insoluble in the non-aqueous solvent by being polymerized, in the presence a dispersion-stabilizing resin, which is soluble in the non-aqueous solvent and is composed of at least one recurring unit represented by the formulae (Ia) and (Ib) having a weight average molecular weight of from 1.times.10.sup.3 to 2.times.10.sup.4 as defined in the specification.The liquid developer according to the present invention is excellent in redispersibility, storability, stability, image-reproducibility and fixability.

Abstract: The invention provides coated carrier particles and dry electrographic developers comprising a mixture of the carrier particles and toner particles. Each of the carrier particles comprises a core particle having a polymeric overcoat comprising a blend of a fluorine-containing polymer and a modifying polymer comprising poly(p-t-butylstyrene) or a copolymer of p-t-butylstyrene and a C.sub.1 -C.sub.4 alkyl methacrylate.

Abstract: Liquid developing agent for electrostatic photography comprising resin grains dispersed in a non-aqueous solvent with an electrical resistance of 10.sup.9 106 cm or more and a permittivity of 3.5 or less, wherein said dispersed resin grains are polymer resin grains produced by a polymerization reaction of a solution containingat least one monofunctional monomer (A) which is soluble in the nonaqueous solvents, but is made insoluble by polymerization, andat least one resin (B) for dispersion stabilization that is soluble in said nonaqueous solvent and is a polymer which has repeating units represented by formula (I) below, a portion of which is crosslinked and in which an acidic group selected fromamong --PO.sub.3 H.sub.2, --SO.sub.3 H, --COOH, --OH, --SH and ##STR1## groups, where R.sup.1 represents a hydrocarbon group, is bonded to only one end of at least one polymer main chain. ##STR2## wherein X.sup.1 represents --COO--, --OCO--, --CH.sub.2 OCO--, --CH.sub.2 COO--, --O-- or --SO.sub.2 --;Y.sup.

Abstract: A specific silicone oil having a vicinal epoxy group is coated on a carrier for a developing or incorporated in a coating resin layer of a carrier for a developer. In this carrier, the spending phenomenon is prevented, the moisture resistance and flowability are improved, and a stable friction chargeability can be maintained for a long time and the durability is highly improved.

Abstract: This invention discloses electrophotogrpahic toners and the methods for their preparation. The electrophotographic toners contain resin and coloring agents as primary components. The resin is a non-crosslinked polymer of vinyl monomers or its mixtures, and has a number average molecular weight (Mn) of 2,000-15,000, a Z average molecular weight (Mz) of not less than 400,000 and Mz/Mn of 50-600. The electrophotographic toners exert an excellent fixing ability at high duplication speed or at lower temperatures.

Abstract: A process for the preparation of polymer particles with an average diameter of from about 0.1 to about 40 microns, which comprises (1) mixing at least one monomer with a free radical polymerization initiator, and an initiator capable of being activated with light, which monomer mixture is dispersed in an aqueous phase containing a surfactant; (2) subjecting the aforementioned mixture of (1) to light irradiation for an effective period of time to accomplish stabilization of the mixture, while initiating photopolymerization of the monomer, and (3) subsequently heating the aqueous phase thereby completing polymerization of the monomer.

Abstract: A resin-coated magnetic carrier for two-component developers which comprises magnetic particles and a resin coating formed on the individual magentic particles is described. The resin coating is made of a cured resin composition comprised of an alkylated melamine resin whose moelcular weight satisfies the followin inequalityM.gtoreq.1100C-400wherein M represents a weight average molecular weight of the resin and C represents the number of carbon atoms in the alkyl moiety, and an acryl-modified silicone resin. The use of the composition is effective in preventing the coated particles from melt adhesion and in forming a smooth and uniform coating layer on individual particles. The resin-coated carrier is significantly reduced in amount of spend carrier and has good durability, moisture resistance, chargeability.

Abstract: The invention provides coated carrier particles suitable for use in dry electrographic developers comprising a mixture of the carrier particles and toner particles. Each of the carrier particles comprises a core particle having a polymeric overcoat comprising poly(p-t-butylstyrene) or a copolymer of p-t-butylstyrene and a C.sub.1 -C.sub.4 alkyl methacrylate, wherein the polymer further comprises sulfur-containing end groups.

Abstract: A dry type toner for electrophotography is disclosed which comprises as the main components (a) a coloring agent; and (b) a polyol resin serving as a binder agent in an effective amount, the polyol resin being prepared by subjecting a bisphenol-type epoxy resin containing epoxy groups, which may contain secondary hydroxyl groups, to reaction steps (1), (2) and (3), or steps (2) and (3), in any sequential combination, until substantially no epoxy groups remain in the polyol resin, wherein the reaction step (1) comprises a step of causing the epoxy groups in the bisphenol-type epoxy resin to react with a primary amine; the reaction step (2) comprising a step of causing the epoxy groups to react with a compound containing one active hydrogen capable of reacting with the epoxy groups; and the reaction step (3) comprising a step of esterifying at least part of the secondary hydroxyl groups or hydroxyl groups produced in the bisphenol-type epoxy resin by reaction step (1) and/or reaction step (2) by use of an ester