JP2009122153A - Organic fine particle composition, method for manufacturing the same, and method for electrophotographic printing using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic fine particle composition that gives a toner having a sharp particle size distribution, a spherical shape and latitude in fixability. <P>SOLUTION: The organic fine particle composition is characterized by that the organic fine particle contains a lithium salt compound expressed by formula (1) or (2) dissolved therein. The diameter of the organic fine particle is preferably from 4 μm to 10 μm. The organic fine particle composition imparts excellent charge control property to toner and prevents adhesion of toner particles, and thereby, the toner can be used for electrophotographic printing while diameters of the organic fine particles are controlled. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention generally relates to an organic fine particle composition, and more particularly to an organic fine particle composition having an excellent charge control function used for electrophotographic printing. The present invention also relates to a method for producing such an organic fine particle composition. The present invention also relates to an electrophotographic printing method using such an organic fine particle composition as a toner.

  Organic fine particles are used, for example, as electrophotographic toners and developers in the field of image processing, and fine particles for various products such as external additives such as fluidity improvers and charge control agents, carriers, and photoconductive fine powders. It is used as an intermediate.

  As a typical example, regarding electrophotographic toner and developer, the developer used in electrophotography, electrostatic recording, electrostatic printing, etc. is, for example, a photosensitive in which an electrostatic image is formed in the development process. It is once attached to a carrier such as a body, and then transferred from a photosensitive member to a transfer medium such as transfer paper in a transfer process, and then fixed on a paper surface in a fixing process. At that time, as a developer for developing the electrostatic image formed on the latent image holding surface, a two-component developer composed of a carrier and a toner, and a one-component developer that does not require a carrier (magnetic toner, Non-magnetic toners are known.

  Conventionally, dry toners as an example of organic fine particles used for electrophotography, electrostatic recording, electrostatic printing, etc. are melt-kneaded and finely pulverized with a toner binder such as a styrene resin and a polyester resin together with a colorant. Things are used.

  In order to obtain high-quality, high-quality images, improvements have been made by reducing the particle size of organic fine particles. Internally, the organic fine particles are further pulverized by contact stress between the developing roller and the toner supply roller, the layer thickness regulating blade, the friction charging blade, etc. There occurs a phenomenon that the image quality is deteriorated due to generation of very fine particles or a fluidizing agent embedded in the organic fine particle surface.

  As a method for solving these problems, a toner production method using a suspension polymerization method or an emulsion polymerization aggregation method has been studied.

  Further, a method called a polymer dissolution suspension method has been proposed (see, for example, Patent Document 1). Unlike suspension polymerization and emulsion polymerization aggregation methods, this method has a wide range of versatile resins that can be used, and is particularly useful for full-color processes that require transparency and smoothness of the image area after fixing. It is excellent in that it can be used. However, the used dispersant is strongly adsorbed on the surface of the toner particles in general, and it is difficult to remove it by a subsequent cleaning operation, and accordingly, the chargeability of the toner is largely governed by the used dispersant. there were. Therefore, the charging speed of the obtained toner is slow and is strongly influenced by humidity.

  In Patent Document 2, the resin used in the polymer dissolution suspension method has a low molecular weight to reduce the viscosity of the dispersed phase, facilitate emulsification, and improve the fixability by carrying out a polymerization reaction in the particles. In particular, the influence of the functional group used for the polymerization reaction cannot be ignored. Especially when an isocyanate compound is used, not only the influence of the dispersant described above but also the chargeability of the resulting urethane and urea groups are strongly controlled. It was a thing.

  In addition to the story of toner, hybridization, mechanofusion, and the like are generally known as surface modification methods for imparting functionality to organic fine particles as mechanical treatment methods. Moreover, as a method of chemically reacting, the techniques of Patent Documents 3 and 4 have been proposed in addition to surface treatment with a silane coupling agent and a titanium coupling agent. Hybridization and mechanofusion, which perform dry mechanical processing, are recognized to have a certain effect as particle surface modification treatment, but these treatments all require high impact force and high energy, and the particles to be processed Receive a history of these processes. Since organic fine particles generally have the property of easily causing morphological changes (crystal morphology), even if these mechanical surface treatment methods are used, even if functionality can be imparted, other performance changes are brought about. The target characteristics were often not obtained.

On the other hand, a surface treatment with a coupling agent typified by a silane coupling agent, a titanium coupling agent or the like is generally used as a chemical reaction treatment method. In addition, there are those used for electrophotographic organic fine particles (for example, Patent Documents 3 and 4). However, these methods are not satisfactory in terms of imparting functionality, and there is a problem that the degree of freedom of the modifier itself is particularly low and the types are limited.
JP-A-7-152202 JP-A-11-149179 JP 2001-343786 A Japanese Patent Laid-Open No. 11-84726

  In addition to the above-mentioned problems, in the conventional pulverized toner, a functional organic molecule called a lipophilic charge control agent (CCA) is added before kneading at the time of toner production, and the functional organic molecule is removed by hot melt kneading. A desired charge control effect is obtained by uniformly dispersing and then pulverizing and exposing a certain amount to the toner surface.

  However, when the functional organic molecule is a highly oleophilic compound, due to its oleophilicity, it is dispersed inside the toner, which is an oil component, or peels off, and there is almost no presence on the toner surface, resulting in an antistatic effect. It was insufficient.

  Further, when the functional organic molecule is a lipophilic compound, it moves from the inside of the toner, which is an oil phase, to the water phase side during the production of the toner, hardly exists on the toner surface, and the charge control effect is not exhibited.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide an organic fine particle composition capable of obtaining a desired charge control effect.

  Another object of the present invention is to provide an organic fine particle composition that provides a toner having a high average charge level, excellent stability over time, a rapid charging speed, and not affected by the environment such as temperature and humidity. It is in.

  Another object of the present invention is to provide an organic fine particle composition having a sharp particle size distribution, a spherical shape, and a toner having a high melt viscosity in which a high molecular weight component having a sufficient fixability is present.

  Still another object of the present invention is an organic fine particle composition that can be used for paints, various coloring materials, fluidity improvers, spacers, storage stabilizers, cosmetics, fluorescent labeling fine particles, in addition to the use of the toner. To provide things.

  Another object of the present invention is to provide a method for producing such an organic fine particle composition.

  Still another object of the present invention is to provide an electrophotographic printing method that faithfully develops a latent image to reproduce a high-quality full-color image.

  Still another object of the present invention is to provide an electrophotographic printing method that reproduces a high-quality full-color image with high transfer efficiency.

The present invention relates to an organic fine particle composition containing at least a resin and a colorant. In the organic fine particles, a lithium salt compound represented by the following general formula (1) or (2) is dissolved. The diameter of each organic fine particle is preferably controlled to 4 μm to 10 μm.

  By selecting the addition amount of the lithium salt compound represented by the above general formula (1) or (2), a desired antistatic effect can be imparted. For example, when used in toner, the toners adhere to each other. Is prevented. As a result, it can be used for electrophotographic printing in a state where the diameter of the organic fine particles is controlled to 4 μm to 10 μm.

  The organic fine particles are preferably those obtained by a suspension polymerization method, an emulsion polymerization aggregation method, a polymer suspension method or a polymer pulverization method.

  The lithium salt compound is preferably contained in an amount of 0.1 to 3 parts by weight with respect to 100 parts by weight of the organic fine particles.

  The lithium salt compound is melted and dissolved in an elastomer having a polyether segment and dispersed in the organic fine particles. The lithium salt compound is contained in an amount of 0.01 to 20 parts by mass with respect to 100 parts by mass of the elastomer. It is preferable that the elastomer containing the lithium salt compound is contained in an amount of 0.01 to 10 parts by mass with respect to 100 parts by mass of the organic fine particles.

  The elastomer having the polyether segment will be further described. From the basic structure, polyether diol, polyether diamine, and modified products thereof, polyether diol segment as a polyether segment forming component, polyether ester having the same segment, Examples thereof include an elastomer having a structure of polyether amide having the same segment and polyether urethane having the same segment.

  Specifically, a block polymer obtained by esterifying a modified polypropylene obtained by reacting polypropylene with maleic anhydride and polyalkylene glycol (polyethylene glycol, polypropylene glycol, etc.) in the presence of a catalyst is suitable. As mentioned.

  The polyether block polyester elastomer can be synthesized by a transesterification reaction or a polycondensation reaction using 1,4-butanediol and polytetramethylene ether glycol as starting materials.

  The polyether ester block polyamide elastomer can be synthesized by a transesterification polycondensation reaction using dimethyl terephthalate, 1,4-butanediol, ε-caprolactone, and the like as starting materials.

  As a preferred embodiment, the lithium salt compound is dissolved in water or a volatile organic solvent and dispersed in the organic fine particles, and the lithium salt compound is added to 100 parts by mass of the water or the volatile organic solvent. Is contained in an amount of 0.01 to 20 parts by mass and contains 0.001 to 0.1 parts by mass of the water or volatile organic solvent containing the lithium salt compound with respect to 100 parts by mass of the organic fine particles. May be.

  In the method for producing an organic fine particle composition according to another aspect of the present invention, resin particles are first prepared. At least the resin particles, the colorant, and the lithium salt compound represented by the general formula (1) or (2) are premixed. The premixed mixture is kneaded using a heated twin-screw kneading extruder to form a kneaded product. The kneaded product is pulverized, and organic fine particles having a diameter of 4 to 10 μm are classified from the pulverized product and filtered out.

  In the production method according to the present invention, it is preferable to use a lithium salt compound represented by the general formula (1) or (2) melted and dissolved in an elastomer having a polyether segment as the lithium salt compound.

  As another embodiment, a lithium salt compound represented by the general formula (1) or (2) dissolved in water or a volatile organic solvent may be used as the lithium salt compound.

  The invention according to another aspect of the present invention relates to an electrophotographic printing method in which fine particles called toner are frictionally charged to form an image using electrostatic force. In addition, as the toner, organic fine particles containing at least a resin and a colorant and further dissolving a lithium salt compound represented by the general formula (1) or (2) are used. The diameter of the organic fine particles is preferably controlled to 4 μm to 10 μm. By using the toner of the present invention, it is possible to provide a developing method, a transfer method, and a process cartridge that are excellent in image quality because the toner is prevented from sticking due to its charge control effect.

  The organic fine particle composition according to the present invention imparts excellent antistatic properties to the toner, prevents the toners from sticking to each other, and in the state where the diameter of the organic fine particles is controlled to 4 μm to 10 μm. Can be used for printing. Therefore, the obtained toner is excellent in image quality, and has excellent fixing performance and storage stability. Further, by using the toner of the present invention, it is possible to provide a developing method, a transfer method, and a process cartridge excellent in image quality.

  The organic fine particle composition of the present invention can be produced by suspension polymerization, emulsion polymerization, polymer suspension and pulverization.

  In the suspension polymerization method, a coloring agent, a release agent, and the like are dispersed in an oily polymerization initiator and a polymerizable monomer, and in an aqueous medium containing a surfactant, other solid dispersants, and the like by an emulsification method. Emulsify and disperse. Thereafter, a polymerization reaction is performed, and the salt compound is added to the resin particle aggregate separated from the suspension, and dissolved or dispersed. Next, after passing through a drying step, the resin particle aggregate is conveyed to a crushing step for crushing the resin particle aggregate to a particle size of the resin particles before substantial aggregation. For crushing, a crusher conventionally used for industrially producing powders, particles and the like can be used without limitation. In the agglomerates, the resin particles are only point-bonded or slightly surface-bonded at the interface, so that the spherical resin particles before aggregation can be easily obtained with a little energy by a pulverizer having a relatively simple mechanism. Can be crushed to an average particle size of.

  In the emulsion polymerization aggregation method, a water-soluble heavy initiator and a polymerizable monomer are emulsified in water using a surfactant, and a latex is synthesized by an ordinary emulsion polymerization technique. Separately, a dispersion in which a colorant, a release agent, and the like are dispersed in an aqueous dispersion medium is prepared, and after mixing, the organic fine particles are obtained by agglomerating to an organic fine particle size and heat-sealing. Thereafter, the salt compound is dissolved or dispersed.

  In the polymer suspension method, water alone may be used as the aqueous medium, but a solvent miscible with water may be used in combination. Examples of the miscible solvent include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), and the like.

  In the oil phase of the organic fine particle composition, the above-described salt compound, resin, prepolymer, pigment and other colorants, a release agent and the like are dissolved / dispersed in a volatile solvent. In order to lower the viscosity of the oil phase and make it emulsifiable, a volatile solvent in which the polyester resin or prepolymer is soluble is used. The solvent preferably has volatility with a boiling point of less than 100 ° C. from the viewpoint of easy removal.

  As the volatile solvent, for example, toluene, xylene, methyl acetate, ethyl acetate, methyl ethyl ketone and methyl isobutyl ketone can be used alone or in combination of two or more.

  In addition, the shape of the organic fine particles can be further adjusted by using a solvent that can be dissolved in an aqueous medium such as alcohol or water. The usage-amount of the solvent with respect to 100 parts of organic fine particle compositions is 10-900 parts normally.

  In order to remove the organic solvent from the obtained emulsified dispersion, a method of gradually elevating the temperature of the entire system and completely removing the organic solvent in the droplets can be employed. Alternatively, it is also possible to spray the emulsified dispersion in a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form organic fine particles, and to evaporate and remove the aqueous dispersion medium together. .

  As a dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, in particular, various air currents heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used is generally used. Sufficient target quality can be obtained in a short time such as spray dryer, belt dryer or rotary kiln.

  When the particle size distribution at the time of emulsification dispersion is wide and washing and drying processes are performed while maintaining the particle size distribution, the particle size distribution can be adjusted by classification into a desired particle size distribution.

  In the classification operation, the fine particle portion can be removed in the liquid by a cyclone, a decanter, centrifugation, or the like. Of course, the classification operation may be performed after obtaining the powder as a powder after drying. The unnecessary fine particles or coarse particles obtained can be returned to the kneading step and used for the formation of particles. At that time, fine particles or coarse particles may be in a wet state.

  The dispersant used is preferably removed from the obtained dispersion as much as possible, but it is preferable to carry out it simultaneously with the classification operation described above.

  The salt compound may be mixed and dissolved in the emulsified dispersion.

  In the pulverization method, an organic fine particle composition can be obtained by kneading and melting the lithium salt compound in a resin and then crushing the resin. Furthermore, an organic fine particle composition can be obtained by adding and kneading an elastomer composition obtained by adding the lithium salt compound to an antistatic elastomer having a polyether segment in advance, followed by crushing.

  The addition amount of the lithium salt compound is preferably 0.001 to 1.0% with respect to the solid content of the organic fine particle composition. When adding the said elastomer composition, it is preferable to add 0.01-2 weight% of elastomers which contain the said lithium salt compound 0.1-20.0% with respect to an elastomer.

  In the present invention, if desired, the obtained dried organic fine particle powder is mixed with other different kinds of particles such as release agent fine particles, charge control fine particles, fluidizing agent fine particles, colorant fine particles and the like. Alternatively, the mixed powder can be fixed and fused on the surface by applying a mechanical impact force to prevent the detachment of the different particles from the surface of the resulting composite particles.

  Specific means include a method of applying an impact force to the mixture by blades rotating at high speed, a method of injecting and accelerating the mixture in a high-speed air stream, and causing particles or composite particles to collide with an appropriate collision plate, etc. is there.

  As the organic fine particles constituting the organic fine particle composition, resin particles made of an acrylic polymer, a styrene polymer, a styrene-acrylic polymer, or the like can be used.

  The acrylic polymer constituting the organic fine particles is a homopolymer or copolymer obtained by polymerizing a monomer selected from acrylic acid or acrylic ester, methacrylic acid or methacrylic ester. Acrylic monomers used to obtain such acrylic polymers include acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, acrylic Dodecyl acid, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate , N-butyl methacrylate, isopropyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethyl methacrylate Minoechiru, and diethylaminoethyl methacrylate.

  Styrene monomers include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p -Tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-phenyl styrene , P-chlorostyrene, 3,4-dichlorostyrene and the like.

  A styrene polymer can be obtained from one or more of the above styrene monomers. In the present invention, one or more other monomers are copolymerized as required. There may be. In this case, it is preferable to use a styrene monomer in the monomer composition at a ratio of 50% by mass or more.

  The styrene-acrylic copolymer constituting the organic fine particles can be obtained by using one or more of the above acrylic monomers and one or more of the above styrenic monomers. In addition, one or two or more types of other monomers may be copolymerized. In this case, in the monomer composition, the total of the acrylic monomer and the styrene monomer is preferably used at a ratio of 50% by mass or more.

  Other monomers include acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide, vinyl esters such as vinyl acetate, vinyl butyrate and vinyl benzoate, and vinyl ethers such as vinyl methyl ether and vinyl ethyl ether. , Vinyl ketones such as vinyl methyl ketone, dienes such as butadiene and isoprene, unsaturated carboxylic acids such as maleic acid and fumaric acid, and the like.

  When the organic fine particles according to the present invention are used as a developer, known dyes and pigments can be used as the colorant. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR) , Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartra Gin Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Red, Lead Zhu, Cadmuum Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, PA Red, Faise Red, Parachlor Ortho Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resolbin GX, Permanent Red F5R, Brilliant Carmine 6B, Pogment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red, Thioindigo Maroon, Oil Quinacridone red, pyrazolone red, polyazo red, chrome vermilion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkaline blue rake, peacock blue rake, Victoria blue rake, metal-free phthalocyanine blue, phthalocyanine blue , Fast Sky Blue, Indanthrene Blue (RS, BC) Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Oxidation Chrome, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Guri Enlake, Malachite Green Lake, Phthalocyanine Green, Anthraquinone Green, Titanium Oxide, Zinc Hana, Litobon and mixtures thereof can be used.

  The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

  The colorant used in the present invention can also be used as a master batch combined with a resin.

  The master batch can be adjusted by mixing and kneading the resin and the colorant under a high shearing force. At this time, an organic solvent can be used to enhance the interaction between the colorant and the resin.

  In addition, a so-called flushing method, which is an aqueous paste of a colorant containing water, is mixed and kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove moisture and the organic solvent. Since the wet cake of the colorant can be used as it is, it does not need to be dried and is preferably used. For mixing and kneading, a high shear dispersion device such as a three-roll mill is preferably used.

  Moreover, a wax can also be contained as a release agent together with a binder and a colorant.

  As the wax, known ones can be used, for example, polyolefin wax (polyethylene wax, polypropylene wax, etc.), long chain hydrocarbon (paraffin wax, sasol wax, etc.), and carbonyl group-containing wax. More preferred are polyalkanoic acid esters.

  The melting point of the wax in the present invention is usually 40 to 160 ° C, preferably 50 to 120 ° C, more preferably 60 to 90 ° C. A wax having a melting point of less than 40 ° C. has an adverse effect on heat resistant storage stability, and a wax having a melting point of more than 160 ° C. tends to cause a cold offset when fixing at a low temperature.

  The melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps, as a measured value at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps have poor effects for improving hot offset resistance and low-temperature fixability.

  The wax content in the toner using the organic fine particles according to the present invention is usually 0 to 40% by weight, preferably 3 to 30% by weight.

  The dry toner can be manufactured by the following method, but is not limited to this.

  In addition, when adjusting the developer, in order to improve the fluidity, storage stability, developability, and transferability of the developer, the developer produced as described above is further added with a hydrophobic silica fine powder or the like. Inorganic fine particles may be added and mixed.

  Examples of the mixing equipment that can be used include a V-type mixer, a rocking mixer, a trading mixer, a Nauter mixer, a Henschel mixer, and the like.

  In order to further adjust the shape of the obtained toner, a toner material composed of a toner binder and a colorant is melt-kneaded and then finely pulverized and then mechanically adjusted using a hybridizer, mechanofusion, etc. The toner material is dissolved and dispersed in a solvent in which the toner binder is soluble, and then the solvent is removed using a spray drying device to obtain a spherical toner. The so-called spray drying method is also used, and the toner is made spherical by heating in an aqueous medium. However, it is not limited to this.

  As the external additive for assisting the fluidity, developability and chargeability of the colored particles obtained in the present invention, inorganic fine particles can be used.

  The proportion of the inorganic fine particles used is preferably 0.01 to 5% by weight of the toner, and particularly preferably 0.01 to 2.0% by weight.

  In order to mix the external additive, a general powder mixer is used.

  When a toner using organic fine particles obtained by the production method of the present invention is used as a two-component developer, it may be used by mixing with a magnetic carrier, and the carrier to toner content ratio in the developer is 100 weight carrier. 1 to 10 parts by weight of toner is preferable with respect to parts.

  As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used.

  The toner using the organic fine particles obtained by the production method of the present invention can also be used as a one-component magnetic toner or non-magnetic toner that does not use a carrier.

  When the lithium salt compound is added to the organic fine particles of the present invention in a liquid, it is preferably performed after washing and removing the surfactant used for the production of the organic fine particles.

  Excess surfactant present in the water is removed by solid-liquid separation operations such as filtration and centrifugation, and the resulting cake and slurry are redispersed in an aqueous medium. Thereafter, an aqueous surfactant solution having a reverse polarity is gradually added with stirring. The reverse polarity surfactant can be used in an amount of 0.01 to 1% by weight based on the solid content of the organic fine particles.

  The toner obtained through each of the above steps has good resolution even when durable printing is performed, and does not cause filming or fogging and has excellent printing durability. According to the production method of the present invention, a toner having such excellent printing performance can be produced stably and efficiently.

  FIG. 1 is a diagram showing an example of the configuration of an image forming apparatus to which toner obtained by the present invention is applied.

  The printing process includes charging, exposure, development, transfer, fixing, and cleaning processes. In the charging process, a voltage is applied to the charging roller 1 to uniformly charge the surface of the photosensitive drum 2. The photosensitive drum 2 is obtained by providing a photoconductive layer on a conductive support drum. This photoconductive layer is composed of, for example, an organic photoreceptor, a selenium photoreceptor, a zinc oxide photoreceptor, an amorphous silicon photoreceptor, or the like. The photoconductive layer is bound to the conductive support drum body. Examples of the resin used for binding the photoconductive layer to the conductive support drum include polyester resin, acrylic resin, polycarbonate resin, phenol resin, and epoxy resin. Among these, polycarbonate resin is preferable.

  In the exposure process, the LED head 3 irradiates light corresponding to the image signal onto the surface of the photosensitive drum 2 to form an electrostatic image.

  In the developing process, first, the toner 6 between them is frictionally charged by friction between the supply roller 4 and the developing roller 5. A voltage is applied to the supply roller 4 and the developing roller 5 so that the toner 6 is attracted to the developing roller 5 side. The toner 6 supplied to the developing roller 5 is held on the roller surface and is formed into a thin layer when passing through the contact portion with the layer regulating blade 7. Here too, the toner 6 is charged by friction between the layer regulating blade 7 and the developing roller 5. Then, the toner 6 formed in a thin layer is conveyed to a contact portion with the photosensitive drum 2 by the rotation of the developing roller 5. Between the photosensitive drum 2 and the developing roller 5, the toner 6 moves to the photosensitive drum 2 side in a portion irradiated with light in the exposure process, and the toner 6 is held by the developing roller 5 in a portion not irradiated with light. Such an electric field is formed.

  In the transfer process, the toner 6 developed on the photosensitive drum 2 is moved onto the medium 9 by electrostatic force. The above operation is sequentially performed for four colors of black, yellow, magenta, and cyan to form a color image on the medium 9. In the figure, 12 is a transfer roller, 13 is a medium conveying belt, and 14 is a conveying roller.

  In the fixing process, the toner 6 on the medium 9 is melted and fixed by heat or pressure by the fixing device 10. In the cleaning process, a small amount of toner 6 remaining on the photosensitive drum 2 without being transferred onto the medium 9 in the transfer process is scraped off by the rubber blade 11.

  In the present invention, the organic fine particles obtained by the present invention are developed by a plurality of developing devices including a developing roller 5 and a layer regulating blade 7 that uniformly regulates the layer thickness of the developer supplied onto the developing roller 5. Used as an agent. The electrostatic latent image divided on each color formed on the single photosensitive drum 2 can be developed by a method of developing with a developer corresponding to each color.

  In the present invention, the organic fine particles obtained by the present invention are provided by a plurality of developing devices including a developing roller 5 and a layer regulating blade 7 for uniformly regulating the layer thickness of the developer supplied onto the developing roller 5. Is used as a developer. The electrostatic latent image divided into each color formed on the single photosensitive drum 2 is developed with a developer corresponding to each color, and the intermediate transfer member can be transferred by an electric field.

  In the present invention, the organic fine particles obtained by the present invention are provided by a plurality of developing devices including a developing roller 5 and a layer regulating blade 7 for uniformly regulating the layer thickness of the developer supplied onto the developing roller 5. Is used as a developer. The electrostatic latent image divided into each color formed on the plurality of photosensitive drums 2 corresponding to the developing device can be developed with a developer corresponding to each color.

  In the present invention, the organic fine particles obtained by the present invention are provided by a plurality of developing devices including a developing roller 5 and a layer regulating blade 7 for uniformly regulating the layer thickness of the developer supplied onto the developing roller 5. Is used as a developer. The electrostatic latent image divided into each color formed on the plurality of photosensitive drums 2 corresponding to the developing device can be developed with a developer corresponding to each color and transferred to an intermediate transfer member by an electric field.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. In addition, all the parts shown below are based on weight.

(Image characteristics test)
Using a copier that operates on the same principle as the electrophotographic copier shown in FIG. 1, 250 images are continuously printed on an A4 size transfer paper with an A size image area ratio of 6%, thereby stabilizing the image density. I examined the sex.

(Charge amount)
About 10 g of developer was put in a 100 cc polyethylene bottle, rotated at 120 rpm at 50 ° C. for 5 minutes, and 900 minutes, and then the charge amount (μC / g, 23 ° C., 60% RH) was measured.

(Blocking resistance test)
About 10 g of the developer was put in a 100 cc polyethylene bottle, left at 50 ° C. for 3 days, and then visually evaluated.

  FIG. 2 is a flowchart illustrating a toner developer manufacturing process according to the first embodiment.

  A mixture of 80 parts of styrene, 20 parts of n-butyl acrylate and 0.5 part of azobisisobutyronitrile was charged into the suspension, heated to 75 ° C. while blowing nitrogen gas, and stirred for 5 minutes. A suspension polymerization reaction was performed. After cooling, the suspension was filtered and dried to obtain resin particles. 80 parts of a magnetic material obtained by adding silicate to magnetite, 5 parts of a colorant (trade name CT-BX121, manufactured by DIC), 4 parts of wax, lithium bis (trifluoromethanesulfonyl) imide (lithium) After 0.05 part of salt compound (1)) was premixed, it was kneaded using a twin-screw kneading extruder set at 130 ° C. The obtained kneaded product is cooled, roughly crushed with a cutter mill, crushed with a fine pulverizer using a jet stream, further classified with a multi-division classifier, filtered, and a diameter of 4 to 4 A toner developer which is an organic fine particle composition having a powder of 10 μm and an average particle diameter of 6.8 μm was obtained.

  In FIG. 3, curve (a) shows the relationship of the abundance ratio of the organic fine particles obtained by this example with respect to the particle diameter (hereinafter abbreviated as particle size distribution). Compared with the particle size distribution of conventional organic fine particles not using the lithium salt compound (curve (b) indicated by a dotted line), this embodiment is characterized in that a particle having a very narrow particle size distribution is obtained. It is considered that the lithium salt compound dissolved in the organic fine particles exhibits a charge control effect, prevents the particles from sticking to each other, and maintains the diameter between 4 to 10 μm. On the other hand, since the organic fine particles obtained by the conventional method do not sufficiently exert the charge control effect, it is considered that the fine particles recombine in a so-called dumpling shape and stick to each other, and the width of the particle size distribution is widened.

  100 parts of the obtained toner and 0.9 parts of positively charged hydrophobic colloidal silica fine powder were mixed to obtain a toner developer.

  The charge amount (μC / g) was −22 (5 minutes) and −21 (900 minutes). The charge amount (μC / g) under the conditions of 30 ° C. and 90% RH was −21 (900 minutes).

  As a result of an image characteristic test using this developer, there was no density unevenness on the image, but a slight decrease in density was observed. As a result of the blocking resistance test, no aggregate was observed.

  FIG. 4 is a flowchart illustrating the toner developer manufacturing process according to the second embodiment.

  Instead of the lithium salt compound (1) in Example 1, a resin composition obtained by melting and dissolving 10 parts of lithium trifluoromethanesulfonate in an elastomer having a polyether segment (Sanconol (registered trademark) TBX-, manufactured by Sanko Chemical Co., Ltd.) 310) A powder having a diameter of 4 to 10 μm and an organic fine particle composition having an average particle diameter of 5.0 μm are added to dry resin particles with the same composition except that 1.0 part of (lithium salt compound (2)) is added. As a result, a toner developer was obtained. The charge amount (μC / g) was −20 (5 minutes) and −20 (900 minutes). As a result of the image characteristic test, there was no density unevenness on the image and the density was stable and good. As a result of the blocking resistance test, no aggregate was observed.

  In this example, Sanconol (registered trademark) TBX-310, which is a resin composition in which a lithium salt compound is dissolved, is exemplified, but the present invention is not limited to this, and instead, general formula (1) or ( A solution prepared by dissolving the lithium salt compound shown in 2) in water or a volatile solvent may be used.

  In the above examples, the case where the organic fine particle composition according to the present invention is used as a toner has been exemplified. However, the present invention is not limited to this, and paints, various color materials, fluidity improvers, spacers, storage It can be used for stabilizers, cosmetics, fine particles for fluorescent labels, and the like.

  Further, in the above examples, lithium bis (trifluoromethanesulfonyl) imide and lithium trifluoromethanesulfonate are exemplified as the lithium salt compound, but the present invention is not limited to this, and lithium tris (trifluoromethanesulfonyl) methane, etc. A lithium salt of a super strong acid is preferably used.

  It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  By using the organic fine particle composition according to the present invention as an electrophotographic printing toner, it is possible to provide a developing method, a transfer method, and a process cartridge excellent in image quality.

1 is a conceptual diagram of an image forming apparatus to which toner obtained by the present invention is applied. FIG. 5 is a flowchart illustrating a toner developer manufacturing process according to the first exemplary embodiment. It is a figure which shows the comparison of the particle size distribution of the organic fine particle obtained by Example 1, and the particle size distribution of the organic fine particle obtained by the prior art. 6 is a flowchart illustrating a toner developer manufacturing process according to Embodiment 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Charging roller 2 Photosensitive drum 3 LED head 4 Supply roller 5 Developing roller 6 Toner 7 Layer regulation blade 9 Medium 10 Fixing device 11 Rubber blade 12 Transfer roller 13 Medium conveyance belt 14 Conveyance roller

Claims (11)

In an organic fine particle composition containing at least a resin and a colorant,
An organic fine particle composition, wherein a lithium salt compound represented by the following general formula (1) or (2) is dissolved in the organic fine particles.
  The organic fine particle composition according to claim 1, wherein the diameter of each organic fine particle is controlled to 4 μm to 10 μm.   The organic fine particle composition according to claim 1 or 2, wherein the organic fine particles are obtained by a suspension polymerization method, an emulsion polymerization aggregation method, a polymer suspension method or a polymer pulverization method.   The organic fine particle composition according to any one of claims 1 to 3, comprising 0.1 to 3 parts by weight of the lithium salt compound with respect to 100 parts by weight of the organic fine particles. The lithium salt compound is melted and dissolved in an elastomer having a polyether segment, and dispersed in the organic fine particles.
The lithium salt compound is contained in an amount of 0.01 to 20 parts by mass with respect to 100 parts by mass of the elastomer.
The organic fine particle composition according to any one of claims 1 to 4, comprising 0.01 to 10 parts by mass of the elastomer containing the lithium salt compound with respect to 100 parts by mass of the organic fine particles. The lithium salt compound is dissolved in water or a volatile organic solvent and dispersed in the organic fine particles,
The lithium salt compound is contained in an amount of 0.01 to 20 parts by mass with respect to 100 parts by mass of the water or the volatile organic solvent,
The organic fine particle composition according to any one of claims 1 to 4, comprising 0.001 to 0.1 parts by mass of the water or volatile organic solvent containing the lithium salt compound with respect to 100 parts by mass of the organic fine particles. object. A step of preparing resin particles;
A step of premixing at least the resin particles, a colorant, and a lithium salt compound represented by the following general formula (1) or (2);
Kneading the premixed mixture using a heated twin-screw kneading extruder to form a kneaded product;
A method of producing an organic fine particle composition comprising: pulverizing the kneaded material; and classifying and taking out organic fine particles having a diameter of 4 to 10 μm from the pulverized material.
  The method for producing an organic fine particle composition according to claim 7, wherein a lithium salt compound represented by the general formula (1) or (2) is melted and dissolved in an elastomer having a polyether segment as the lithium salt compound.   The method for producing an organic fine particle composition according to claim 7, wherein a lithium salt compound represented by the general formula (1) or (2) is dissolved in water or a volatile organic solvent as the lithium salt compound. In an electrophotographic printing method in which fine particles called toner are frictionally charged and image formation is performed using electrostatic force.
An electrophotographic printing method comprising using, as the toner, organic fine particles containing at least a resin and a colorant and further dissolving a lithium salt compound represented by the following general formula (1) or (2).
  The electrophotographic printing method according to claim 10, wherein the diameter of the organic fine particles is controlled to 4 μm to 10 μm.