Abstract: The encapsulated toner for heat-and-pressure fixing of the present invention has a heat-fusible core material containing at least a thermoplastic resin and a coloring agent and a shell formed thereon so as to cover the surface of the core material. Moreover, the encapsulated toner has the following properties: 1) The glass transition temperature ascribed to the thermoplastic resin used as a main component of the heat-fusible core material is 10.degree. C. to 50.degree. C.; 2) A minimum load required for 58 compression of a particle size of the encapsulated toner is from 5 to 50 mgf, and a minimum load required for 10% compression of a particle size of the encapsulated toner is from 10 to 100 mgf, when a compressive variation of one toner particle is measured by a micro compression testing machine under the given conditions; and 3) The difference in cohesiveness before and after keeping the toner standing at 50.degree. C.

Abstract: A method for producing an encapsulated toner for heat-and-pressure fixing, which has a heat-fusible core material containing at least a thermoplastic resin and a coloring agent and a shell formed thereon so as to cover the surface of the core material, having the steps of coating the surface of the core material with a hydrophilic shell-forming material to form precursor particles; adding at least a vinyl polymerizable monomer and an initiator for vinyl polymerization to an aqueous suspension of the precursor particles to absorb them into the precursor particles; and then polymerizing the monomer components in the precursor particles. The method of the present invention offers toners which not only have improved storage stability but also are excellent in offset resistance, fixable at a low temperature and are further capable of forming clear images free from background.

Abstract: The present invention is directed to an encapsulated toner for heat-and-pressure fixing having a heat-fusible core material containing at least a thermoplastic resin and a coloring agent and a shell formed thereon so as to cover the surface of the core material. An amorphous polyester is used as the main component of the shell, and the amount of the amorphous polyester is normally 3 to 50 parts by weight, based on 100 parts by weight of the core material. The encapsulated toner of the present invention is excellent in offset resistance, fixable even at a low temperature and excellent in blocking resistance when it is used for heat-and-pressure fixing using a heat roller.

Abstract: The method of producing a binder resin has the steps of blending in advance (a) a starting material monomer mixture for two polymerization reaction types, (b) a compound which can react with both of starting material monomers for the two polymerization reaction types, and (c) a tricarboxylic or higher polycarboxylic acid or a derivative thereof, the two polymerization reaction types having independent reaction paths to each other in one reaction vessel; and concurrently carrying out the two polymerization reactions in one reaction vessel to give the binder resin. According to the present invention, the binder resin which has an excellent environmental stability in the tribo electric charge and the image quality, and also has good pulverizability and transparency can be produced. Moreover, in a fixing method using a heat roller, fixing at a low temperature can be performed without using an offset inhibiting liquid.

Abstract: A developer composition of the present invention contains a toner having at least a binder resin, a coloring agent and a toner scum preventive. The binder resin contains as a main component a polyester resin or a resin produced by concurrently carrying out addition polymerization and condensation polymerization in one reaction vessel. By using the toner of the present invention, since the formation of toner scum on the carrier surface can be prevented for a long period of time in the service life of the developer while retaining the low-temperature fixing ability of the toner, the carrier resistance and the triboelectric charge can be stably maintained, thereby providing a developer composition with a long service life. Accordingly, besides having a long service life mentioned above, the developer composition is highly suitably used for a high-speed semiconductive magnetic development.

Abstract: A method of forming fixed images including uniformly charging a photoconductor, selectively exposing the photoconductor to light to form an electrostatic latent image, developing the electrostatic latent image with a thermally dissociating encapsulated toner to form a visible image, transferring the formed toner image to a recording medium, and fixing the transferred the toner image onto the recording medium, the fixing process being carried out at a temperature of not less than 40.degree. C. and not more than 120.degree. C. and by using a fixing roller exerting a nip pressure of less than 4 kg/cm.

Abstract: A method of forming fixed images includes charging a photoconductor; exposing the photoconductor to light; developing an electrostatic latent image, such that a toner is applied to the electrostatic latent image formed on a transfer film moving in partially close contact with the photoconductor to form a visible image; transferring the formed visible image onto a recording medium such as a recording paper; and fixing the transferred visible image onto the recording medium. The toner is an encapsulated toner, the photoconductor is a heat-resistant photoconductor, and the transfer process and the fixing process are simultaneously carried out on the surface of the heat-resistant photoconductor covered with the transfer film onto the preheated recording medium.

Abstract: The present invention is directed to a developing method of a magnetic encapsulated toner, which can be fixed even at a nip pressure of 0.01 to 0.1 kg/cm without a supply of silicone oil onto a surface of a heat roller, using a toner projection developing device. The fixing in the present invention is carried out at a temperature of not more than 120.degree. C. and at a nip pressure of 0.01 to 4 kg/cm. By using these methods, the miniaturization of the overall apparatus can be achieved.

Abstract: A method of forming fixed images comprising charging a photoconductor, exposing the photoconductor to light, developing a latent electrostatic image whereby a toner is applied to the latent electrostatic image formed on the photoconductor to form a visible image, transferring the formed visible image to a recording medium, and fixing the transferred visible image onto the recording medium, wherein the fixing process comprises preheating the toner transferred onto the recording medium using an endless heating film, and pressure fixing the toner.

Abstract: A method of forming fixed images includes charging a photoconductor; exposing the photoconductor to light; applying a thermally dissociating encapsulated toner, or an encapsulated toner whose shell is made of amorphous polyester to an electrostatic latent image formed on the photoconductor, developing the electrostatic latent image to form a visible image; transferring the formed visible image to a recording medium having a softening point of 100.degree. C. to 200.degree. C.; and fixing the transferred visible image onto the recording medium at a temperature of not less than 80.degree. C. and not more than 120.degree. C. by using a fixing roller which exerts a nip pressure of from 0.1 to 4.0 kg/cm.

Abstract: The present invention is directed to a toner composition containing a polyester resin having an OHV/AV value of 1.2 or more as a major component of a binder resin wherein AV is an acid value of said polyester and OHV is a hydroxyl value thereof and hydrophobic silica having a degree of hydrophobic property of 80 or more or having a pH value of 5.5 to 8 in water-methanol solution. A toner composition of the present invention exhibits no decrease in electric charge retainability and fluidity of a toner and a visible image with good quality for a long period with no black spots occurring.

Abstract: A process for producing a binder resin is disclosed, which comprises blending in a reactor a raw monomer for a first polymerization system and a raw monomer for a second polymerization system which undergoes polymerization through a reaction path different from a reaction path of said first polymerization system and then conducting said first and second polymerization reactions in the same reactor. A toner and a developer composition employing the binder resin are also disclosed. The binder resin can easily be pulverized and can give toners and developer compositions which hold a good charge and from which an environmentally stable fixed image can be obtained.

Abstract: The present invention is directed to an encapsulated toner for heat-and-pressure fixing, which has a heat-fusible core material containing at least a coloring agent and a shell formed thereon so as to cover the surface of the core material. The core material includes a thermoplastic resin as its main components produced by a polymerization reaction, at the time of encapsulation, of 0.05 to 20 parts by weight of the (A) .alpha.,.beta.-ethylenic copolymerizable monomer having an acid anhydride group and 99.95 to 80 parts by weight of the (B) other .alpha.,.beta.-ethylenic copolymerizable monomer. Alternatively, the core material contains a copolymer having one or more acid anhydride groups added as one component of the core material resin-constituting material at the time of encapsulation.

Abstract: A method of forming fixed images including uniformly charging a photoconductor selectively exposing the photoconductor to light, developing an electrostatic latent image whereby a toner is applied to the electrostatic latent image formed on the photoconductor to form a visible image, transferring the formed visible image to a recording medium, and fixing the transferred visible image onto the recording medium, in which the toner is a thermally dissociating encapsulated toner, the photoconductor is a heat-resistant photoconductive film belt, and the transferring process and the fixing process are simultaneously carried out on the heat-resistant photoconductive film belt at a temperature of from 40.degree. to 120.degree. C.

Abstract: A powder ink having in the structure a heat-fusible core comprising a thermo-melting substance and a coloring matter and a shell covering the core surface and comprising a resin product obtained by reacting:(1) 0 to 30 mole % of a monovalent isocyanate compound and/or a monovalent isothiocyanate compound and(2) 100 to 70 mole % of at least divalent isocyanate and/or at least divalent isothiocyanate compound with(3) 0 to 30 mole % of a compound having an active hydrogen atom to react with the isocyanate and isothiocyanate groups of (1) ana (2) and(4) 100 to 70 mole % of a compound having at least two active hydrogen atoms to react with the isocyanate and isothiocyanate groups of (1) and (2); at a molar ratio of (1) and (2) to (3) and (4) in the range between 1:1 and 1:2. At least 30 percent of all the linkages involved in the isocyanates and the isothiocyanates in the resin product are thermally linkages.

Abstract: An encapsulated toner for heat-and-pressure fixing having excellent offset resistance and blocking resistance, being fixed at a low fixing temperature and being regulated with the charging properties thereof from the inside of the encapsulated toner to stably and repeatedly form a scum-free, clear image many times, comprised of a heat-fusible core containing at least a coloring material, a binder and an electric charge control agent selected from the group consisting of a positive electric charge control agent, a negative electric charge control agent and a mixture thereof at a weight ratio of one to the other ranging from 1:0 (exclusive) to 1:0.

Abstract: The present invention is directed to a toner composition containing a polyester resin as a major component of a binder resin and 0.01 to 1.5 parts by weight of hydrophobic silica having a degree of hydrophobic property of not less than 80, and/or having a pH value of 5.5 to 8 when 4% by weight of hydrophobic silica is dispersed in water-methanol solution (1:1) to 100 parts by weight of the toner.

Abstract: A developer composition for electrophotography comprising a binding resin and a colorant, said binding resin comprising a first linear polyester having a softening point, Tsp, in the range of from 105.degree. C. to 170.degree. C. exclusive, and a second linear polyester having a softening point, Tsp, in the range of from 80.degree. C. to 105.degree. C. exclusive and lower than that of the first linear polyester by at least 10.degree. C., the weight ratio of the first linear polyester to the second linear polyester being (80:20) to (20:80) is disclosed.The developer composition of the present invention is excellent in the hot offset resistance, low temperature fixation, smoothness of fixed face, blocking resistance and transparency.

Abstract: A developer composition for electrophotography comprising a binding resin and a colorant, said binding resin comprising a specified nonlinear first polyester and a specified linear second polyester, the weight ratio of the first polyester to the second polyester being (80:20) to (20:80), is disclosed.The developer composition of the present invention is excellent in hot offset resistance, low temperature fixation, smoothness and transparency of fixed face, and blocking resistance.

Abstract: A capsulated toner for heat pressure fixation comprising a heat-meltable core material and an outer shell, said core material containing a colorant and a thermoplastic resin as a major constituent, produced by copolymerizing (A) an .alpha.,.beta.-ethylenically copolymerizable monomer having an amino group and (B) .alpha.,.beta.-ethylenically copolymerizable monomer other than (A), said outer shell being provided so as to cover the surface of the core material. When the capsulated toner of the present invention is used, the dependency of the amount of electrification upon the environment is small because the electrification can be regulated from within the capsulated toner. Further, because the offset resistance in a heat pressure fixation system, such as a heat roller, is excellent, the fixation can be conducted at a low temperature. Further, the blocking resistance is so good that a clear image, free from fogging, can be stably formed over a plurality of uses.