JP6468939B2 - toner - Google Patents

Description

  The present invention relates to a toner used in an image forming method using an electrophotographic system such as a copying machine, a printer, a facsimile machine, and a multifunction machine of these.

  In recent years, image forming apparatuses such as electrophotographic copying machines are widely used throughout the world as information output devices not only for copying originals but also linked to other information devices through digitization, and have high definition and high quality. The performance required for toners such as high image quality, high speed, and high reliability is increasing.

  In particular, since the environment used by the market has expanded, it has been required to provide stable image quality independent of the environment.

  Further, from the viewpoint of reliability, there is a need to provide an image forming apparatus that can output a long-term image output without impairing image quality.

  For example, in electrophotographic toner, it is known that the chargeability is lowered in a high humidity environment, and the image quality may be impaired due to the influence. As a specific example, the toner is slightly developed in a white portion (non-printing portion) that is not originally printed, and appears as a background stain, or fogging occurs.

  In addition, in the toner, external additives which are functional particles for imparting functions such as fluidity and chargeability and a spacer effect between the toner and each member adhere to the surface of the toner base particles (resin). What you have is common. However, it is known that the toner is subjected to a share in the image forming apparatus by repeating the image output over a long period of time, and the external additive is liberated from the mother particles or buried in the mother particles. As a result, the chargeability and fluidity of the toner are lowered, and the spacer effect on the photosensitive drum is reduced, so that it becomes difficult to transfer all the toner from the photosensitive drum to the recording medium or the intermediate transfer body, that is, transfer. Efficiency will decrease. As a result, the image quality may be impaired, for example, the density uniformity in a high density image or the like is significantly reduced.

  Further, in the fixing system in the image forming apparatus, from the viewpoint of energy saving by reducing power consumption, a light pressure fixing system such as a film fixing and a belt fixing with a small heat capacity is becoming mainstream from a conventional hard roller system having a large heat capacity. .

  In the light pressure fixing system, the heat capacity of the fixing member is reduced in order to shorten the time required to reach the fixing set temperature (temperature control temperature) and to improve the quick start. In order to reduce the heat capacity of the fixing member, the temperature reduction degree of the fixing member becomes larger when performing high-speed continuous copying as compared with the conventional hard roller system. Therefore, a toner that can be fixed at a lower temperature is required, and as a performance desired for the toner, further improvement in the low-temperature fixability has been demanded.

  In order to satisfy the above requirements, a toner having high environmental charge stability, no deterioration in image quality even after long-term image output, that is, high durability and low temperature fixability is required more than ever. Various attempts have been proposed.

  In Patent Document 1, it is proposed to use a polyolefin resin having a cyclic structure as a binder resin for toner. Polyolefin resin having a cyclic structure is colorless and transparent, has high light transmittance, and has low hygroscopicity. Therefore, a release agent is further added to a toner containing a polyolefin resin having a cyclic structure as a binder resin. As a result, it is possible to provide a toner excellent in productivity, heat storage, fixing characteristics, transparency, and environmental stability by including a polypropylene wax or polyethylene wax and a charge control agent that is an organoboron compound. It is described that it is possible to provide a developing device that suppresses the occurrence of fog and ghost phenomenon.

JP 2004-219507 A

  Even with the toner as described above, there is room for improvement with respect to a decrease in transferability when an image is output over a long period of time. The decrease in transferability is considered due to the fact that the external additive is embedded in the toner base particles.

  The present invention was made to satisfy all of the environmental charge stability, durability, and low-temperature fixability, and maintains high transfer efficiency that can suppress the burying of the external additive in the toner base particles throughout the durability. An object of the present invention is to provide a toner capable of providing a stable image quality that does not depend on the environment over a long period of time.

The present invention is a toner having a surface composition comprising an olefin copolymer having a cyclic structure and polyethylene,
The polyethylene relates to a toner having a density of less than 0.930 g / cm ³ and a weight average molecular weight of 10,000 to 5,000,000.

  According to the present invention, it is possible to provide stable image quality over a long period of time without depending on the environment.

Schematic diagram of image forming apparatus Illustration of the image forming apparatus

  In the following, embodiments of the present invention are shown, and the present invention will be described more specifically.

<Toner>
When the external additive adhering to the surface of the toner base particles is buried in the toner base particles in the developing device, the adhesion force of the toner to the photosensitive drum 1 increases. For this reason, the transfer efficiency is lowered, and the transfer remaining amount on the photosensitive drum 1 is increased. As a result, image defects such as a decrease in density uniformity in a high density image occur.

  As a result of repeated studies by the present inventors, whether or not the external additive attached to the toner base particles is buried in the base particles due to the share in the developing device is strongly influenced by the plastic deformation resistance of the resin on the toner surface. I found out.

  The particle size of the external additive on the surface of the toner base particles is about several nm to 500 nm, but when image output is performed, a share is applied in various places inside the developing device. For example, a share is applied to the toner at the rubbing portions such as between the developing roller 14 and the supply roller 15, between the developing roller 14 and the regulating blade 16, and between the developing roller 14 and the photosensitive drum 1. At that time, the external additive on the surface of the toner base particles is pressed against each member, and the resin on the toner surface is deformed. Since the share is removed after passing through the rubbing part, the external additive on the surface of the toner base particles is also unloaded, but the amount of plastic deformation is determined according to the elastic deformation rate of the resin on the toner surface, and plastic deformation has occurred. The external additive is embedded by the amount.

By including not only an olefin polymer having a cyclic structure as a surface composition of the toner but also a polyethylene having a low density of less than 0.930 g / cm ³ and a weight average molecular weight of 10,000 to 5,000,000, The high elastic deformation performance of low density polyethylene can be imparted to the toner surface. As a result, it is possible to increase the resistance to burying the external additive on the surface of the toner base particles, and stable and good image formation can be achieved over a long period of time.

  Incidentally, “having a surface composition containing an olefin copolymer having a cyclic structure and polyethylene” means that the olefin copolymer having a cyclic structure and polyethylene adhere to the surface of the toner base particles as external additives. Instead, it means that the surface portion of the toner base particles is composed of a composition containing an olefin copolymer having a cyclic structure and polyethylene.

  Hereinafter, each component will be described in detail while explaining the toner production method.

As an example of a toner production method, an olefin polymer having a cyclic structure of 20 to 500 nm and a density of 0.930 g on the surface of a core particle having a size of several μm containing a binder resin, a pigment, a wax, a charge control agent and the like. The resin particles containing polyethylene having a weight average molecular weight of 10,000 to 5,000,000 less than / cm ³ are adhered by an acid agglomeration method, and further thermally / mechanically crushed to smooth the surface, thereby to As the resin, a toner containing an olefin polymer having a cyclic structure and low density polyethylene was prepared.

  Details of the toner manufacturing method in this embodiment will be described below.

When the toner of the present invention is produced by the above method,
(1) producing core particles,
(2) A step of producing an aqueous dispersion of resin fine particles containing an olefin polymer having a cyclic structure of 20 nm to 500 nm and polyethylene having a density of less than 0.930 g / cm ³ and a weight average molecular weight of 10,000 to 5,000,000. ,
(3) a step of attaching the resin fine particles to the surface of the core particles;
(4) a step of smoothing the surface of the toner containing the fine particles adhering to the core particle surface;
is necessary.

(1) Preparation of core particles As the binder resin that can be used for the core particles of the toner of the present invention, known resins can be used, and vinyl resins such as styrene-acrylic resins, polyester resins, or a combination thereof. Hybrid resin or the like can be used.

  In a method for directly obtaining toner particles by a polymerization method, a monomer for forming them is used.

  Specifically, styrene monomers such as styrene, o- (m-, p-) methylstyrene, o- (m-, p-) ethylstyrene; methyl acrylate, ethyl acrylate, propyl acrylate, acrylic Acrylate monomers such as butyl acrylate, octyl acrylate, dodecyl acrylate, stearyl acrylate, behenyl acrylate, 2-ethylhexyl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, acrylonitrile, acrylamide; Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, octyl methacrylate, dodecyl methacrylate, stearyl methacrylate, behenyl methacrylate, 2-ethylhexyl methacrylate, dimethylaminoethyl methacrylate, methacrylate Le diethylaminoethyl, methacrylonitrile, methacrylate based monomers, such as methacrylic acid amide; butadiene, isoprene, olefinic monomers such as cyclohexene is preferably used.

  These may be used alone or generally in J. Brandrup, E.I. H. Immergut, "Polymer Handbook", (USA), 3rd edition, John Wiley & Sons, 1989, p. The theoretical glass transition temperature (Tg) described in 209-277 is used by appropriately mixing monomers so that the glass transition temperature (Tg) is 40 to 75 ° C.

  When the theoretical glass transition temperature is less than 40 ° C., problems are likely to occur in terms of storage stability and durability stability of the toner. On the other hand, when it exceeds 75 ° C., the transparency of the image in the case of forming a full-color image of the toner. Decreases.

  Furthermore, in the present invention, in order to increase the mechanical strength of the toner particles and to control the molecular weight of the binder resin, a crosslinking agent can be used during the synthesis of the binder resin.

  Examples of the crosslinking agent used for the core particle of the toner of the present invention include divinylbenzene, 2,2-bis (4-acryloxyethoxyphenyl) propane, 2,2-bis (4-methacryloxy) as a bifunctional crosslinking agent. Phenyl) propane, diallyl phthalate, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl Glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 200, # 400, # 600 diacrylate, dipropylene glycol diacrylate Rate, polypropylene glycol diacrylate, and those obtained by changing the polyester type diacrylate, and the above diacrylate dimethacrylate.

  Polyfunctional crosslinkers include pentaerythritol triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate and its methacrylate, triallyl cyanurate, triallyl isocyanurate and triallyl Trimellitate is mentioned.

  These cross-linking agents are preferably used in an amount of 0.05 to 10 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the monomer, from the viewpoint of toner fixability and offset resistance. Is the case.

  The toner of the present invention may be either magnetic toner or non-magnetic toner. When used as a magnetic toner, the following magnetic materials are preferably used. That is, iron oxide such as magnetite, maghemite, ferrite, iron oxide containing other metal oxides, metal such as Fe, Co, Ni, or these metals and Al, Co, Cu, Pb, Mg, Examples thereof include alloys with metals such as Ni, Sn, Zn, Sb, Be, Bi, Cd, Ca, Mn, Se, Ti, W, and V, and mixtures thereof.

Examples of the magnetic material include triiron tetroxide (Fe ₃ O ₄ ), γ-iron trioxide (γ-Fe ₂ O ₃ ), zinc iron oxide (ZnFe ₂ O ₄ ), and iron yttrium oxide (Y ₃ Fe). ₅ O ₁₂ ), iron cadmium oxide (CdFe ₂ O ₄ ), iron gadolinium oxide (Gd ₃ Fe ₅ O ₁₂ ), iron oxide copper (CuFe ₂ O ₄ ), iron oxide lead (PbFe ₁₂ O ₁₉ ), nickel iron oxide (NiFe ₂ O ₄ ), iron oxide neodymium (NdFe ₂ O ₃ ), iron barium oxide (BaFe ₁₂ O ₁₉ ), iron magnesium oxide (MgFe ₂ O ₄ ), iron manganese oxide (MnFe ₂ O ₄ ), iron lanthanum oxide (LaFeO ₃ ), iron powder (Fe), cobalt powder (Co), nickel powder (Ni) and the like.

  The magnetic materials described above are used alone or in combination of two or more.

  A magnetic material particularly suitable for the purposes of the present invention is a fine powder of iron trioxide or γ-iron trioxide.

These magnetic materials have an average particle diameter of 0.1 to 2 μm (preferably 0.1 to 0.3 μm), magnetic properties when 795.8 kA / m is applied, and a coercive force of 1.6 to 12 kA / m, saturation. From the viewpoint of toner developability, the magnetization is preferably 5 to 200 Am ² / kg (preferably 50 to 100 Am ² / kg), and the residual magnetization is 2 to 20 Am ² / kg.

  The amount of these magnetic materials added is when 10 to 200 parts by mass, preferably 20 to 150 parts by mass of the magnetic material is used with respect to 100 parts by mass of the binder resin.

  On the other hand, as a colorant when used as a nonmagnetic toner, known colorants such as various conventionally known dyes and pigments can be used.

  For example, as a colorant for magenta, for example, C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 163, 202, 206, 207, 209; I. Pigment Violet 19; C.I. I. Vat Red 1, 2, 10, 13, 15, 23, 29, 35 and the like.

  Examples of cyan colorants include C.I. I. Pigment Blue 2, 3, 15: 1, 15: 3, 16, 17, 25, 26; I. Vat Blue 6; C.I. I. Acid Blue 45; or a copper phthalocyanine pigment in which 1 to 5 phthalimidomethyl groups are substituted on the phthalocyanine skeleton.

  Examples of the colorant for yellow include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 65, 73, 74, 83, 93, 155, 180; I. Solvent Yellow 9, 17, 24, 31, 35, 58, 93, 100, 102, 103, 105, 112, 162, 163; C.I. I. Vat Yellow 1, 3, 20, etc. are mentioned.

  As the black colorant, for example, carbon black, aniline black, acetylene black, and those that are toned in black using the yellow / magenta / cyan colorant shown above can be used.

  The amount of these colorants to be used varies depending on the kind of the colorant, but the total amount is 0.1 to 60 parts by mass, preferably 0.5 to 50 parts by mass with respect to 100 parts by mass of the binder resin.

  Specific examples of the wax component that can be used in the present invention include petroleum wax such as paraffin wax, microcrystalline wax, and petrolatum and derivatives thereof, montan wax and derivatives thereof, hydrocarbon wax and derivatives thereof according to the Fischer-Tropsch method. , Polyolefin waxes typified by polyethylene and derivatives thereof, natural waxes such as carnauba wax and candelilla wax and derivatives thereof, and the like include oxides, block copolymers with vinyl monomers, and graft modified products. Is also included.

  Also included are alcohols such as higher aliphatic alcohols, fatty acids such as stearic acid and palmitic acid, or acid amides and esters of these compounds, hydrogenated castor oil and derivatives thereof, plant waxes, animal waxes and the like.

  These can be used alone or in combination.

  The added amount of the wax component is preferably 2.5 to 15.0 parts by mass, more preferably 3.0 to 10.0 parts by mass with respect to 100 parts by mass of the binder resin. More preferred.

  If the added amount of the wax component is less than 2.5 parts by mass, oilless fixing becomes difficult. If the added amount exceeds 15.0 parts by mass, the amount of the wax component in the toner is too large. Many of them are present, which may hinder desired charging characteristics, which is not preferable.

  In the toner of the present invention, a charge control agent may be used for the purpose of adjusting charging characteristics. Examples of charge control agents that can be used include the following.

  Negatively chargeable charge control agents include polymer compounds having sulfonic acid groups, sulfonic acid groups or sulfonic acid ester groups, salicylic acid derivatives and their metal complexes, monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids Aromatic mono- and polycarboxylic acids, metal salts thereof, anhydrides, esters, phenol derivatives such as bisphenol, urea derivatives, boron compounds, calixarene, and the like.

  Examples of positively chargeable charge control agents include nigrosine-modified products with nigrosine and fatty acid metal salts, guanidine compounds, imidazole compounds, tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate. Quaternary ammonium salts such as, and onium salts such as phosphonium salts thereof and their lake pigments, triphenylmethane dyes and these lake pigments (as rake agents include phosphotungstic acid, phosphomolybdic acid, Phosphotungstic molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.), metal salts of higher fatty acids, dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide Diorganotin oxides such as, dibutyl tin borate, dioctyl tin borate, and the like diorgano tin borate such as dicyclohexyl tin borate.

  In the present invention, the number average particle diameter (D1) of the toner is preferably from 3.0 to 15.0 μm, more preferably from the viewpoint of obtaining charging stability and high-quality images. 0 to 12.0 μm.

  The number average particle diameter (D1) of the toner of the present invention in this embodiment is mainly determined by the particle diameter of the core particles, but the adjustment method differs depending on the core particle manufacturing method.

  For example, in the case of the suspension polymerization method, it can be adjusted by controlling the concentration of the dispersing agent used in preparing the aqueous dispersion medium, the reaction stirring speed, or the reaction stirring time.

  The core particles used in the toner of the present invention can be manufactured by various toner manufacturing methods. For example, a kneading and pulverization method in which a binder resin, a pigment, and a release agent are mixed and kneaded, pulverized, and classified to obtain toner particles; a polymerizable monomer, a pigment, and a release agent are mixed, dispersed, or dissolved; Suspension polymerization method in which toner particles are obtained by granulation in an aqueous medium to obtain toner particles; a binder resin, a pigment, and a release agent are dissolved or dispersed in an organic solvent, granulated in an aqueous medium, and then removed from the solvent. A solution suspension method for obtaining toner particles by emulsion dispersion method in which fine particles of a binder resin, a pigment, and a release agent are finely dispersed in an aqueous medium, and the toner particles are aggregated to obtain toner particles. Can be mentioned.

  The core particles used in the toner of the present invention may be produced by any method, but the suspension polymerization method, the dissolution suspension method, which can obtain a toner having a high average circularity relatively easily, It is preferably obtained by a production method of granulating in an aqueous medium such as an emulsion aggregation method.

  When producing core particles by suspension polymerization, a polymerizable monomer composition is prepared by mixing a polymerizable monomer, a colorant, a wax component, a polymerization initiator, and the like, which are the binder resin. The polymerizable monomer composition is dispersed in an aqueous medium to granulate the polymerizable monomer composition particles, and then the polymerizable monomer in the polymerizable monomer composition particles in the aqueous medium. Particles are obtained by polymerizing.

  Examples of the polymerization initiator used in the suspension polymerization method include known polymerization initiators such as azo compounds, organic peroxides, inorganic peroxides, organometallic compounds, and photopolymerization initiators. Can be mentioned.

  More specifically, 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (4-methoxy-2,4-dimethyl) Valeronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), azo polymerization initiators such as dimethyl 2,2′-azobis (isobutyrate), benzoyl peroxide, ditert-butyl peroxide, tert Organic peroxide polymerization initiators such as butyl peroxyisopropyl monocarbonate, tert-hexyl peroxybenzoate, tert-butyl peroxybenzoate, inorganic peroxide polymerization initiators such as potassium persulfate and ammonium persulfate, Hydrogen peroxide-ferrous, BPO-dimethylaniline, cerium (IV) salt-Arco Redox initiators such as Le systems.

  Examples of the photopolymerization initiator include acetophenone series, benzoin ether series, and ketal series.

  These methods can be used alone or in combination of two or more.

  The concentration of the polymerization initiator is preferably in the range of 0.1 to 20 parts by mass, more preferably in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the polymerizable monomer. is there.

  The kind of the polymerizable initiator is slightly different depending on the polymerization method, but is used alone or in combination with reference to the 10-hour half-life temperature.

  The aqueous medium used in the suspension polymerization method preferably contains a dispersion stabilizer.

  As the dispersion stabilizer, known inorganic and organic dispersion stabilizers can be used.

  Examples of inorganic dispersion stabilizers include calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, magnesium carbonate, calcium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, and calcium sulfate. , Barium sulfate, bentonite, silica, alumina and the like. Examples of the organic dispersion stabilizer include polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, starch and the like.

  Nonionic, anionic and cationic surfactants can also be used.

  Examples thereof include sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, calcium oleate and the like.

  Among the above dispersion stabilizers, in the present invention, it is preferable to use a poorly water-soluble inorganic dispersion stabilizer that is soluble in an acid.

  In the present invention, when preparing an aqueous dispersion medium using a hardly water-soluble inorganic dispersion stabilizer, these dispersion stabilizers are added in an amount of 0.2 to 2 with respect to 100 parts by mass of the polymerizable monomer. From the viewpoint of droplet stability in the aqueous medium of the polymerizable monomer composition, it is preferable to use it in a proportion that is in the range of 0.0 part by mass.

  Moreover, in this invention, it is preferable to prepare an aqueous medium using the water of the range of 300 to 3000 mass parts with respect to 100 mass parts of polymerizable monomer compositions.

  In the present invention, when preparing an aqueous medium in which the poorly water-soluble inorganic dispersion stabilizer is dispersed, a commercially available dispersion stabilizer may be used as it is, but a dispersion having a fine uniform particle size may be used. In order to obtain stabilizer particles, it is preferable to prepare by preparing the poorly water-soluble inorganic dispersion stabilizer under high-speed stirring in water.

  For example, when calcium phosphate is used as a dispersion stabilizer, a preferable dispersion stabilizer can be obtained by mixing a sodium phosphate aqueous solution and a calcium chloride aqueous solution under high speed stirring to form calcium phosphate fine particles.

  When the toner core particles are produced by the emulsion aggregation method, for example, the core particles can be produced through the following steps.

  That is, a step of preparing an aqueous dispersion of toner constituents such as the binder resin, colorant, and wax (dispersion step), followed by a step of mixing these aqueous dispersions and aggregating to form aggregate particles (aggregation) Steps), and heating and fusing the aggregate particles (fusing step), washing step, and drying step, toner core particles can be obtained.

  In the step of dispersing each toner component, a dispersant such as a surfactant can be used. Specifically, it is dispersed in an aqueous medium together with a toner constituent and a surfactant. The aqueous dispersion is produced by a known method. For example, a media-type disperser such as a rotary shear type homogenizer, a ball mill, a sand mill, or an attritor, a high-pressure opposed collision disperser, or the like is preferably used.

  Examples of the surfactant include water-soluble polymers, inorganic compounds, and ionic or nonionic surfactants. In particular, ionicity with high dispersibility is preferable from the viewpoint of dispersibility, and an anionic surfactant is particularly preferably used.

  Further, from the viewpoint of detergency and surface activity, the molecular weight of the surfactant is preferably 100 to 10,000, more preferably 200 to 5,000.

  Specific examples of the surfactant include water-soluble polymers such as polyvinyl alcohol, methylcellulose, carboxymethylcellulose, and sodium polyacrylate; sodium dodecylbenzenesulfonate, sodium octadecylsulfate, sodium oleate, sodium laurate, stearin Anionic surfactants such as potassium acid; Cationic surfactants such as laurylamine acetate and lauryltrimethylammonium chloride; Zwitterionic surfactants such as lauryldimethylamine oxide; Polyoxyethylene alkyl ether and polyoxyethylene alkylphenyl Surfactants such as nonionic surfactants such as ether and polyoxyethylene alkylamine; tricalcium phosphate, aluminum hydroxide, calcium sulfate, carbonic acid Calcium, and inorganic compounds such as barium carbonate.

  In addition, these may be used individually by 1 type and may be used in combination of 2 or more type as needed.

  The method for forming the aggregate particles is not particularly limited, but a pH adjuster, a flocculant, a stabilizer, and the like are added and mixed in the aqueous dispersion mixture, and the temperature, mechanical power (stirring) The method of adding etc. suitably can be illustrated suitably.

  Although it does not specifically limit as said pH adjuster, Acids, such as alkalis, such as ammonia and sodium hydroxide, nitric acid, and a citric acid, are mention | raise | lifted.

  The flocculant is not particularly limited, but includes inorganic metal salts such as sodium chloride, magnesium carbonate, magnesium chloride, magnesium nitrate, magnesium sulfate, calcium chloride, and aluminum sulfate, as well as divalent or higher metal complexes, etc. Is given.

  Examples of the stabilizer include surfactants. Although it does not specifically limit as surfactant, For example, polyvinyl alcohol, methylcellulose, carboxymethylcellulose, water-soluble polymers, such as sodium polyacrylate; sodium dodecylbenzenesulfonate, sodium octadecyl sulfate, sodium oleate, Anionic surfactants such as sodium laurate and potassium stearate; cationic surfactants such as laurylamine acetate and lauryltrimethylammonium chloride; zwitterionic surfactants such as lauryldimethylamine oxide; polyoxyethylene alkyl ether; Surfactants such as nonionic surfactants such as polyoxyethylene alkylphenyl ether and polyoxyethylene alkylamine; tricalcium phosphate, aluminum hydroxide Calcium sulfate, calcium carbonate, and inorganic compounds such as barium carbonate. In addition, these may be used individually by 1 type and may be used in combination of 2 or more type as needed.

  The average particle size of the aggregated particles formed here is not particularly limited, but it is usually preferable to control the average particle size of the toner particles to be obtained to be approximately the same. Control can be easily performed, for example, by appropriately setting / changing the temperature at the time of addition / mixing of the flocculant or the like and the conditions of the stirring and mixing. Furthermore, in order to prevent fusion between the toner particles, the pH adjusting agent, the surfactant and the like can be appropriately added.

  In the fusing step, toner particles are formed by fusing the aggregate particles with heating.

  The heating temperature may be between the glass transition temperature (Tg) of the resin contained in the aggregate particles and the decomposition temperature of the resin. For example, under the same agitation as in the aggregation step, the progress of aggregation is stopped by adding a surfactant or adjusting the pH, and the aggregate particles are fused by heating to a temperature equal to or higher than the glass transition temperature of the resin particles.・ Match them together.

  The heating time may be such that the fusion is sufficiently performed. Specifically, the heating may be performed for about 10 minutes to 10 hours.

(2) Step of preparing an aqueous dispersion of resin fine particles containing an olefin polymer having a cyclic structure and polyethylene having a density of less than 0.930 g / cm ³ and an average molecular weight of 10,000 to 5,000,000 Next, the cyclic structure The production process of an aqueous dispersion liquid of resin fine particles containing an olefin-based polymer having a density of less than 0.930 g / cm ³ and polyethylene having a weight average molecular weight of 10,000 to 5,000,000 and the step of attaching the fine particles are described in detail. However, the step of attaching the fine particles may be performed before or after the fusing step. In some cases, the step of smoothing the toner surface (4) described later and the fusing step may be the same.

  The olefin polymer having a cyclic structure used in the present invention includes, for example, a metallocene catalyst, a Ziegler catalyst, and a metathesis polymerization, that is, a catalyst for double bond opening and ring opening polymerization reaction. It is a polymer obtained by the polymerization method used. This cyclic olefin polymer is known per se, and synthesis examples thereof are disclosed in, for example, JP-A-5-339327, JP-A-5-9223, JP-A-6-271628, European Patent Application Publication (A No. 203799, 407870, 283164, 156464, and the like.

  Preferably, the cyclic olefin polymer has a lower alkene having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms (α-olefin, acyclic olefin in a broad sense) and 3 to 17 carbon atoms, preferably 5 carbon atoms. It is a copolymer with a cyclic and / or polycyclic compound (cyclic (cyclo) olefin) having at least one double bond of ˜12 and is colorless and transparent and has a high light transmittance. Examples of the lower alkene constituting the polymer include ethylene, propylene, and butylene, and examples of the cyclic olefin include norbornene, tetracyclododecene (TCD), dicyclopentadiene (DCPD), and cyclohexene. Among them, particularly preferably, ethylene is selected as the lower alkene and norbornene is selected as the cyclic olefin.

  According to the above document, the cyclic olefin polymer comprises one or more cyclic olefin monomers, optionally with one acyclic olefin monomer and -78 to 150 ° C, preferably 20 to 80 ° C, pressure It can be obtained by polymerizing at 0.01 to 64 bar in the presence of a cocatalyst such as aluminoxane and a catalyst composed of at least one metallocene composed of, for example, zirconium or hafnium. Other useful polymers are described in European Patent Application (A) 317262, and hydrogenated polymers and copolymers of styrene and dicyclopentadiene can also be used.

In addition, as the cyclic olefin polymer used in the present invention,
i) The number average molecular weight is preferably 100 to 100,000, more preferably 500 to 50,000,
ii) The weight average molecular weight is preferably 200 to 300,000, preferably 3000 to 200,000,
iii) What a glass transition point is -20 degreeC-180 degreeC is preferable, More preferably, it is 40-80 degreeC.

Moreover, as the low density polyethylene having a density of less than 0.930 g / cm ³ used in the present invention, a polymer obtained by a known polymerization method can be used.

  Specifically, there are high-pressure low-density polyethylene obtained by a high-pressure method, and medium-low pressure polyethylene in which α-olefins and ethylene are copolymerized at a medium-low pressure using a catalyst. It can be used.

  Various high-pressure polyethylenes have been proposed as known production methods, and these can be appropriately selected and used.

  For example, in a high-pressure polyethylene production method using radical polymerization, radical chain reaction occurs, and the radical movement causes a molecular structure with various length branches. Since crystallization is inhibited, a low-density and flexible polyethylene can be produced.

  In addition, regarding the medium-low pressure method polyethylene, various known production methods have been proposed, and these can be appropriately selected and used.

  For example, those produced using a metallocene catalyst as described in JP-A-11-60617 and the like can be used. In this reaction, what is usually obtained has a linear structure, and ethylene homopolymerization is hardly branched, and high-density polyethylene is produced. However, α-olefins such as propylene, 1-butene and 1-hexene are produced. Copolymerization with polymers can introduce short branches and lower crystallinity to obtain linear low density polyethylene.

  In such a polymerization method using a catalyst in which a metal atom becomes an active site, in addition to solution polymerization in which polyethylene is dissolved in a solvent, a supported catalyst on silica or a magnesium compound is used, and polyethylene produced in the solvent is used. Various processes have been developed and utilized, such as slurry polymerization in which the polymer exists as a slurry, and gas phase polymerization that polymerizes in a floating state in ethylene or other gas. It is possible to select and use a known process as appropriate. It is also possible to adjust the molecular weight distribution and the like by changing the conditions in two or more continuous reaction vessels for polymerization.

  Polyethylene is required to have a weight average molecular weight of 10,000 to 5,000,000, but preferably 30,000 to 200,000.

  Next, details of the process for preparing the aqueous dispersion of resin fine particles will be described.

After weighing a resin containing an olefin polymer having a cyclic structure and a resin containing polyethylene having a density of less than 0.930 g / cm ³ and a weight average molecular weight of 10,000 to 5,000,000 at a desired ratio, The oil phase dissolved in a solvent insoluble in water and the aqueous phase in which an anionic surfactant is dissolved in ion-exchanged water are mixed, and shear force is applied by a stirrer, so that the oil phase size is several. A μm oil-in-water (O / W type) emulsion is prepared.

  The obtained emulsion can be further subjected to a high-shearing force and, in some cases, a wet atomization device that can apply a high-shearing force under heating (for example, Nanomizer manufactured by Yoshida Kikai Kogyo Co., Ltd., Starburst manufactured by Sugino Machine Co., Ltd.). By performing the treatment a plurality of times, an oil-in-water (O / W type) emulsion having an oil phase size of 20 nm to 500 nm is prepared.

Thereafter, the solvent is removed by distillation under reduced pressure, thereby containing an olefin polymer having a cyclic structure of 20 nm to 500 nm and a polyethylene having a density of less than 0.930 g / cm ³ and a weight average molecular weight of 10,000 to 5,000,000. An aqueous dispersion in which resin fine particles to be dispersed are dispersed can be obtained.

(3) Step of adhering the resin fine particles according to (2) to the surface of the core particles according to (1) In an aqueous dispersion of core particles in which the core particles prepared in (1) are dispersed with an anionic surfactant In addition, an aqueous dispersion of resin fine particles containing the olefin polymer having a cyclic structure prepared in the above (2) and polyethylene having a density of less than 0.930 g / cm ³ and a weight average molecular weight of 10,000 to 5,000,000 is desired. The mixture is stirred and dilute hydrochloric acid as a flocculant is added little by little to the mixed solution while stirring, so that an olefin polymer having a cyclic structure and a weight average molecular weight of 10,000 to 5,000,000 with a density of less than 0.930 g / cm ^3. As a result, an aqueous dispersion of core particles to which resin fine particles containing polyethylene that are substantially uniformly attached can be obtained.

  In addition to the wet method described above, a dry method using a high-speed fluidized mixer such as a Henschel mixer can be used as a method for coating the resin particles on the surface of the core particles.

  The ratio of the cyclic olefin polymer and polyethylene in the surface composition is preferably such that the olefin copolymer is more than the polyethylene.

(4) The step of smoothing the surface of the toner containing the resin fine particles attached to the surface of the core particles The core particles to which the resin fine particles obtained in the step (3) are substantially uniformly attached are dry and wet. Either or both can be used to smooth the fine resin particles on the surface to obtain substantially circular toner particles.

  As an example of the wet process, for example, an aqueous dispersion of core particles to which the resin fine particles obtained in the process described in the above (3) adhere substantially uniformly is heated under desired conditions to melt the resin fine particles on the surface. Thus, the surface is smoothed according to the shape of the core particles. When heating is performed until a predetermined average circularity is achieved, the mixture is cooled to room temperature under appropriate conditions.

  Toner particles can be obtained by washing, filtering, drying, etc. the toner particles obtained after this step.

  Further, as an example of the dry process, the core particle aqueous dispersion obtained in the process described in (3) above is washed, filtered, and dried to obtain core particles on which the fine particles adhere substantially uniformly, and the dried state Using a device such as a Henschel mixer or a hybridizer, applying a shear force under the desired conditions and time mechanically crushes the resin particles on the core particles and smoothes the surface to obtain toner particles. It is also possible.

  In the toner of the present invention, it is preferable to add an external additive to the obtained toner from the viewpoint of charging characteristics and durability characteristics. The type and amount of the external additive cannot be generally defined, but fine powders such as silica, titanium oxide, alumina, or double oxides thereof, or those obtained by surface treatment thereof can be used.

  Next, an image forming apparatus capable of forming an image using the toner of the present invention will be described.

  FIG. 1 is a schematic configuration diagram of an image forming apparatus. The image forming apparatus A shown in FIG. 1 is a full color laser printer using an electrophotographic process. The overall schematic configuration of the image forming apparatus A that is an embodiment of the present invention will be described below. However, the dimensions, materials, shapes, and relative arrangements of the components described in the embodiments described below are intended to limit the scope of the present invention only to those unless otherwise specified. It is not a thing.

  An image forming apparatus applied to an embodiment to which the present invention is applied is shown in FIGS. In this image forming apparatus, the photoreceptor 1 as an image carrier is rotated in the direction of the arrow and is charged to a uniform potential Vd by a charging roller 2 as a charging device. Next, it is exposed by laser light from the laser optical device 3 as an exposure device, and an electrostatic latent image is formed on the surface thereof. The electrostatic latent image is developed by the developing device 4 and visualized as a toner image. The visualized toner image on the photoreceptor 1 is transferred to the intermediate transfer member 6 by the primary transfer device 5 and then transferred to the paper 8 as a recording medium by the secondary transfer device 7. Untransferred toner remaining on the photoreceptor 1 without being transferred is scraped off by a cleaning blade 9 which is a cleaning device. The cleaned photoreceptor 1 repeats the above-described operation to form an image. On the other hand, the paper 8 on which the toner image has been transferred is fixed by the fixing device 10 and then discharged outside the apparatus.

  As shown in FIG. 2, the photosensitive member 1, the charging roller 2, the developing device 4, and the cleaning blade 9 are integrally configured as a cartridge 11 that can be attached to and detached from the main body. Four mounting portions for the cartridge 11 are prepared in the main body. A cartridge 11 filled with toners of yellow, magenta, cyan, and black is mounted from the upstream side in the moving direction of the intermediate transfer member 6, and a color image is formed by sequentially transferring to the intermediate transfer member 6. Can do.

  The photoconductive drum 1 is formed by laminating an organic photoconductor, which is formed by laminating a positive charge injection preventing layer, a charge generation layer, and a charge transport layer in this order on an Al cylinder as a conductive substrate. Further, arylate was used as the charge transport layer of the photoreceptor 1, and the thickness of the charge transport layer was adjusted to 23 μm.

  The charge transport layer is formed by dissolving a charge transport material together with a binder in a solvent. Examples of organic charge transport materials include acrylic resins, styrene resins, polyesters, polycarbonate resins, polyarylate, polysulfone, polyphenylene oxide, epoxy resins, polyurethane resins, alkyd resins, and unsaturated resins. These charge transport materials can be used alone or in combination of two or more.

In the charging roller 2, a semiconductive rubber layer is provided on a metal core as a conductive support, and the resistance of the charging roller is about 10 when a voltage of 200 V is applied to the conductive drum. Indicates a resistance of ⁵ Ω.

  The developing device 4 includes a toner 12 that is a developer, a developing container 13 that is a developer container, a developing roller 14 that is a developer carrying member, a supply roller 15 that supplies the toner 12 to the developing roller 14, and development. A regulating blade 16 that is a developer regulating member that regulates toner on the roller 14 is provided.

  The developing roller 14 is provided with a conductive rubber layer 14b containing a conductive agent around a cored bar electrode 14a having an outer diameter of 6 mm, which is a conductive support, and the outer diameter of the base of the developing roller 14 is 11.5 mm. did. Here, as the material of the rubber layer, silicon rubber, urethane rubber, EPDM (ethylene / propylene copolymer), hydrin rubber, rubber mixed with these, or generally rubber can be used. In this example, the base was formed by forming silicon rubber 2.5 mm and urethane layer 10 μm. Moreover, as a conductive agent, a desired resistance value can be obtained by dispersing carbon particles, metal particles, ion conductive particles, and the like. In this example, carbon particles were used. Further, in order to adjust the hardness of the entire developing roller, the developing roller 14 having a desired hardness was produced by adjusting the amount of silicon rubber and the amount of silica as a filler.

  The supply roller 15 rotates in contact with the developing roller 14, and one end of the regulating blade 16 is in contact with the developing roller 14.

  The supply roller 15 is provided with a urethane foam layer 15b around a cored bar electrode 15a having an outer diameter of 5.5 mm which is a conductive support. The outer diameter of the entire supply roller 15 including the foamed urethane layer 15b is 13 mm. The intrusion amount of the supply roller 15 and the developing roller 14 is 1.2 mm. The supply roller 15 rotates in a direction in which the speeds of the supply roller 15 and the developing roller 14 are opposite to each other. The powder pressure of the toner 12 existing around this acts on the urethane foam layer 15b, and the supply roller 15 rotates, whereby the toner 12 is taken into the urethane foam layer. The supply roller 15 including the toner 12 supplies the toner 12 to the developing roller 14 at a contact portion with the developing roller 14, and further rubs the toner 12 to give a preliminary triboelectric charge to the toner 12. On the other hand, the supply roller that supplies toner to the developing roller also has a role of peeling off toner remaining on the developing roller without being developed in the developing unit.

  The toner 12 supplied from the supply roller to the developing roller 14 reaches the regulating blade 16 and is adjusted to a desired charge amount and toner layer thickness. The regulating blade 16 is a SUS blade having a thickness of 80 μm, and is disposed in the direction against the rotation of the developing roller 14. The regulating blade 16 regulates the toner 12 on the developing roller 14 to obtain a uniform toner layer thickness and obtain a desired charge amount by frictional charging by rubbing. Further, a voltage having a potential difference of −200 V with respect to the developing roller 14 was applied to the regulating blade 16. This potential difference is for stabilizing the toner coat layer.

  The toner layer formed on the developing roller by the regulating blade is transported to the developing unit in contact with the photosensitive drum, and reverse development is performed in the developing unit.

  At the contact position A, the intrusion amount of the developing roller 14 into the photosensitive member 1 is set to 40 μm by a roller (not shown) at the end of the developing roller 14. By being pressed against the photosensitive drum, the surface of the developing roller is deformed, so that a developing nip can be formed and development can be performed in a stable contact state. The developing roller 14 rotates in the same direction at a circumferential speed ratio of 117% with respect to the photosensitive member 1 in the photosensitive member 1 and its developing nip. The reason for providing such a peripheral speed difference has a role of stabilizing the amount of toner to be developed.

  Next, specific voltages in the present embodiment will be described. By applying -1050V to the charging roller, the photosensitive drum surface is uniformly charged to -500V to form a dark potential (Vd). Potential / Vl). At this time, by applying a voltage (Vdc) of −300 V to the developing roller, the negative polarity toner is transferred to a bright potential and is subjected to reversal development.

  Also, | Vd−Vdc | was called Vback, and Vback was set to 200V.

  Further, the amount of toner to be filled in the developing device was set to an amount that can print 3000 images with an image ratio of 5%. A specific example of a horizontal line with an image ratio of 5% means an image in which 19 dot line non-printing is repeated after printing 1 dot line.

  In the image forming process, the photosensitive drum 1 is rotationally driven in the direction of arrow r in the figure by the image forming apparatus at a speed of 120 mm / sec. In addition, the image forming apparatus has a low speed mode with a process speed of 60 mm / sec in order to secure a heat quantity for fixing when a thick recording paper (thick paper) is passed. In this embodiment, the operation is performed only in two types of process modes. However, a plurality of process modes may be provided depending on the recording paper, and control corresponding to each process mode can be executed. May be.

  In the following, detailed description will be given of the production process of the toner used in each example and comparative example.

<Example 1>
(1) Step of producing core particles As core particles, resin fine particles C1 were produced by suspension polymerization. Detailed steps are shown below.

[Polymerizable monomer composition preparation step]
The following composition was mixed and then dispersed for 3 hours by a ball mill.
-Styrene 82.0 parts-2-ethylhexyl acrylate 18.0 parts-Divinylbenzene 0.1 part-C.I. I. Pigment Blue 15: 3 5.5 parts / Polyester resin 5.0 parts (Polycondensate of propylene oxide modified bisphenol A and isophthalic acid, glass transition point 65 ° C., weight average molecular weight (Mw) 10,000, number average molecular weight (Mn 6000)
The obtained dispersion was transferred to a reactor equipped with a propeller stirring blade, heated to 60 ° C. while stirring at a rotation speed of 300 rpm, and then ester wax (peak temperature of maximum endothermic peak in DSC measurement: 70 ° C., number average molecular weight (Mn 704) 12.0 parts and 3.0 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) were added and dissolved to obtain a polymerizable monomer composition.

[Dispersion stabilizer preparation process]
High-speed stirrer K. 710 parts of ion-exchanged water and 450 parts of 0.1 mol / L-sodium phosphate aqueous solution were added to a 2 l four-necked flask equipped with a homomixer (manufactured by Primix), and the mixture was stirred at 60 ° C. while stirring at 12,000 rpm. Heated. To this, 68.0 parts of 1.0 mol / L-calcium chloride aqueous solution was added, and an aqueous dispersion medium containing calcium phosphate as a minute hardly water-soluble dispersion stabilizer was prepared.

[Granulation and polymerization process]
The polymerizable monomer composition was put into the aqueous dispersion medium and granulated for 15 minutes while maintaining the rotation speed of 12000 rpm. Thereafter, the high-speed stirrer was replaced with a propeller stirring blade, the polymerization was continued for 5 hours at an internal temperature of 60 ° C., the internal temperature was then raised to 80 ° C., and the polymerization was further continued for 3 hours. After completion of the polymerization reaction, the residual monomer was distilled off at 80 ° C. under reduced pressure, and then the mixture was cooled to 30 ° C. to obtain a polymer fine particle dispersion.

[Washing process]
The polymer fine particle dispersion was transferred to a washing container, and while stirring, diluted hydrochloric acid was added to adjust the pH to 1.5. The dispersion was stirred for 2 hours and then solid-liquid separated with a filter to obtain polymer fine particles. This was put into 1200 parts of ion-exchanged water and stirred to obtain a dispersion again, followed by solid-liquid separation with a filter. This operation was performed three times to obtain resin fine particles C1 as core particles.

(2) A step of producing an aqueous dispersion of resin fine particles containing an olefin polymer having a cyclic structure and polyethylene having a density of less than 0.930 g / cm ³ and an average molecular weight of 10,000 to 5,000,000. 75 parts by mass of a plastic company TOPAS (TM))-Polyethylene resin (Exelen FX351: Sumitomo Chemical Co., Ltd., density 0.898 g / cm ³ , weight average molecular weight (Mw) 80000) 25 parts by mass-300 parts by mass of xylene-Anionic interface Activating agent (Daiichi Kogyo Seiyaku Co., Ltd. non-sar LN1) 8 parts by mass ・ Ion-exchanged water 925 parts by mass COC resin as a resin containing an olefin polymer having a cyclic structure, polyethylene resin and xylene heated at 80 ° C. Mix and dissolve to prepare an oil phase, and mix and dissolve the anionic surfactant and ion-exchanged water. To prepare a water phase. The oil phase and the water phase are mixed, and stirred for about 30 minutes at 8000 to 9000 rpm in a robotics manufactured by Primix under a heating environment of 80 ° C., and an oil-in-water droplet having an oil phase size of about 1 μm (O / W type) An emulsion was made.

  Further, the obtained emulsion was heated to 80 ° C. and treated about three times with a starburst manufactured by Sugino Machine, to produce an oil-in-water (O / W type) emulsion having an oil phase size of about 100 nm.

  This emulsion was distilled under reduced pressure to remove xylene. As a result, an aqueous dispersion E1 (solid content concentration 10% by mass) in which resin fine particles containing a COC resin of about 80 nm and polyethylene were dispersed was prepared.

(3) Step of attaching the resin fine particles described in (2) to the surface of the core particles described in (1) a) 10 parts by mass of core particles C1 b) 0.1% by mass aqueous solution of an anionic surfactant (Daiichi Kogyo) (Pharmaceutical company: Neogen RK)
48 parts by mass c) 0.2% by mass aqueous solution of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Nonsal LN1)
0.5 parts by weight d) 133 parts by weight of ion-exchanged water e) 10 parts by weight of resin fine particle aqueous dispersion E1 f) 0.1% by weight aqueous solution of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK)
115.2 parts by mass The core particles C1: a) prepared in the step (1), an anionic surfactant 0.1% by mass aqueous solution: b), and an anionic surfactant 0.2% by mass aqueous solution: A core particle dispersion is prepared by mixing c) and ion-exchanged water: d).

  Also, the resin fine particle aqueous dispersion prepared in the step (2): e) and the anionic surfactant 0.1% by mass aqueous solution: f) are mixed to prepare a shell fine particle dispersion.

  The prepared core particle dispersion and shell fine particle dispersion are mixed, and the mixture is heated with stirring to 43 ° C. in a heating water bath. When the liquid temperature reaches 43 ° C., 2 mol / L hydrochloric acid is added dropwise at a rate of 14 mL / min while stirring is continued. At any time, a small amount of the mixed solution is extracted, and until the filtrate passed through the 2 μm microfilter becomes transparent (that is, almost no resin fine particles exist in a dispersed state in the mixed solution, and almost all the resin fine particles adhere to the core particles. Up to this point, hydrochloric acid was added to prepare an aqueous dispersion T1 of core particles in which resin fine particles adhered substantially uniformly.

(4) The step of smoothing the surface of the toner containing the resin fine particles attached to the surface of the core particles The aqueous dispersion of the particles attached with the resin fine particles obtained in (3) above is repeatedly washed with water and filtered to the interface. The active agent was washed and then dried with a drier to produce particles T2 to which resin fine particles adhered substantially uniformly.

  Thereafter, the particle T2 is treated with a hybridizer type 1 manufactured by Nara Machinery Co., Ltd. at 2500 rpm for 6 minutes to fix and smooth the resin fine particles on the surface of the particle T2, and as a resin on the toner surface, an olefin copolymer having a cyclic structure is used. A toner using a resin containing a polymer and low-density polyethylene was produced.

With respect to the toner particles obtained in the above examples, 100 parts by mass of toner particles were added 1.8 parts by mass of hydrophobized silica fine powder having a specific surface area measured by the BET method of 200 m ² / g. (Mitsui Mining Co., Ltd.) was dry-mixed and externally added.

<Example 2>
The present embodiment basically conforms to the first embodiment, but differs in the following points.

In step (2) of Example 1, the resin containing an olefin polymer having a cyclic structure and the resin containing low-density polyethylene were changed to the following types and ratios, respectively.
COC resin (TOPAS (TM) manufactured by Polyplastics) 70 parts by mass Polyethylene resin (Sumikasen F-200 manufactured by Sumitomo Chemical Co., Ltd .: density 0.924 g / cm ³ , weight average molecular weight (Mw): 70,000) 30 parts by mass

<Example 3>
The present embodiment basically conforms to the first embodiment, but differs in the following points.

In step (2) of Example 1, the resin containing an olefin polymer having a cyclic structure and the resin containing low-density polyethylene were changed to the following types and ratios, respectively.
COC resin (TOPAS (TM) manufactured by Polyplastics) 75 parts by mass Polyethylene resin 1 (Exelen FX452 manufactured by Mitsui Chemicals, Ltd .: density 0.880 g / cm ³ , weight average molecular weight (Mw): 80000) 12.5 parts by mass Polyethylene resin 2 (Mitsui Chemicals Sumikasen F-200: density 0.924 g / cm ³ , weight average molecular weight (Mw): 70000) 12.5 parts by mass

<Example 4>
The present embodiment basically conforms to the first embodiment, but differs in the following points.

In step (2) of Example 1, the resin containing an olefin polymer having a cyclic structure and the resin containing low-density polyethylene were changed to the following types and ratios, respectively.
COC resin 1 (Polyplastics TOPAS (TM)) 50 parts by mass COC Resin 2 (Polyplastics TOPAS (TB)) 30 parts by mass Polyethylene resin (Sumitomo Chemical Exelen FX351: density 0.898 g / cm ³ , weight average molecular weight (Mw) 80000) 20 parts by mass

<Example 5>
The present embodiment basically conforms to the first embodiment, but differs in the following points.

In step (2) of Example 1, the resin containing an olefin polymer having a cyclic structure and the resin containing low-density polyethylene were changed to the following types and ratios, respectively.
COC resin 1 (Polyplastics TOPAS (TM)) 50 parts by weight COC resin 2 (Polyplastics TOPAS (TB)) 30 parts by weight Polyethylene resin (Sumitomo Chemical Exelen FX452: density 0.880 g / cm ³ , weight average molecular weight (Mw): 80000) 15 parts by mass

<Example 6>
The present embodiment basically conforms to the first embodiment, but differs in the following points.

In step (2) of Example 1, the resin containing an olefin polymer having a cyclic structure and the resin containing low-density polyethylene were changed to the following types and ratios, respectively.
COC resin 1 (Appell (APL8008T) manufactured by Mitsui Chemicals) 30 parts by mass COC resin 2 (TOPAS (TM) manufactured by Polyplastics) 30 parts by mass Polyethylene resin (Excellen FX452 manufactured by Sumitomo Chemical Co., Ltd .: density 0.880 g / cm ³ , weight average molecular weight (Mw): 80000) 20 parts by mass

<Example 7>
The present embodiment basically conforms to the first embodiment, but differs in the following points.

In step (2) of Example 1, the resin containing an olefin polymer having a cyclic structure and the resin containing low-density polyethylene were changed to the following types and ratios, respectively.
COC resin (TOPAS (TM) manufactured by Polyplastics) 75 parts by mass Polyethylene resin (Flow beads CL2080 manufactured by Sumitomo Seika Co., Ltd .: density 0.919 g / cm ³ , weight average molecular weight (Mw): 75000) 25 parts by mass

<Example 8>
The present embodiment basically conforms to the first embodiment, but differs in the following points.

In step (2) of Example 1, the resin containing an olefin polymer having a cyclic structure and the resin containing low-density polyethylene were changed to the following types and ratios, respectively.
COC resin (TOPAS (TM) manufactured by Polyplastics) 50 parts by mass Polyethylene resin (Excellen FX351 manufactured by Sumitomo Chemical Co., Ltd., density 0.898 g / cm ³ , weight average molecular weight (Mw) 80000) 50 parts by mass

<Example 9>
The present embodiment basically conforms to the first embodiment, but differs in the following points.

In step (2) of Example 1, the resin containing an olefin polymer having a cyclic structure and the resin containing low-density polyethylene were changed to the following types and ratios, respectively.
COC resin (TOPAS (TM) manufactured by Polyplastics) 25 parts by mass Polyethylene resin (Excellen FX351 manufactured by Sumitomo Chemical Co., Ltd., density 0.898 g / cm ³ , weight average molecular weight (Mw) 80000) 75 parts by mass

<Example 10>
The present embodiment basically conforms to the first embodiment, but differs in the following points.

In step (2) of Example 1, the resin containing an olefin polymer having a cyclic structure and the resin containing low-density polyethylene were changed to the following types and ratios, respectively.
-COC resin (TOPAS (TM) manufactured by Polyplastics) 40 parts by mass-Polyethylene resin (Excellen FX452 manufactured by Sumitomo Chemical Co., Ltd .: density 0.880 g / cm ³ , weight average molecular weight (Mw): 80000) 60 parts by mass

<Example 11>
The present embodiment basically conforms to the first embodiment, but differs in the following points.

In step (2) of Example 1, the resin containing an olefin polymer having a cyclic structure and the resin containing low-density polyethylene were changed to the following types and ratios, respectively.
-50 parts by mass of COC resin (Appell (APL8008T) manufactured by Mitsui Chemicals)-50 parts by mass of polyethylene resin (Excellen FX452 manufactured by Sumitomo Chemical Co., Ltd .: density 0.880 g / cm ³ , weight average molecular weight (Mw): 80000)

<Example 12>
The present embodiment basically conforms to the first embodiment, but differs in the following points.

In step (2) of Example 1, the resin containing an olefin polymer having a cyclic structure and the resin containing low-density polyethylene were changed to the following types and ratios, respectively.
COC resin (TOPAS (TM) manufactured by Polyplastics) 75 parts by mass Polyethylene resin 1 (Exelen FX452 manufactured by Mitsui Chemicals, Ltd .: density 0.880 g / cm ³ , weight average molecular weight (Mw): 80000) 12.5 parts by mass -Polyethylene resin 2 (Mitsui Chemicals Sumikasen F-200: density 0.924 g / cm < ³ >, weight average molecular weight (Mw): 70000) 12.5 mass parts Moreover, in the process (3) of Example 1, resin fine particles The number of charged parts of the aqueous dispersion was changed from 10 parts by weight to 20 parts by weight.

<Example 13>
The present embodiment basically conforms to the first embodiment, but differs in the following points.

In step (2) of Example 1, the resin containing an olefin polymer having a cyclic structure and the resin containing low-density polyethylene were changed to the following types and ratios, respectively.
COC resin 1 (Polyplastics TOPAS (TM)) 50 parts by mass COC Resin 2 (Polyplastics TOPAS (TB)) 30 parts by mass Polyethylene resin (Sumitomo Chemical Exelen FX351: density 0.898 g / cm ³ , weight average molecular weight (Mw) 80000) 20 parts by mass Further, in the step (3) of Example 1, the number of charged parts of the resin fine particle aqueous dispersion was changed from 10 parts by mass to 20 parts by mass.

<Example 14>
The present embodiment basically conforms to the first embodiment, but differs in the following points.

  In step (3) of Example 1, the number of charged resin fine particle aqueous dispersions was changed from 10 parts by weight to 2 parts by weight.

<Comparative Example 1>
This comparative example basically conforms to the first embodiment, but differs in the following points.

In step (2) of Example 1, the resin containing low-density polyethylene was not mixed, and the resin containing an olefin polymer having a cyclic structure was used in the following ratio.
・ COC resin (TOPAS (TM) manufactured by Polyplastics) 100 parts by mass

<Comparative example 2>
This comparative example basically conforms to the first embodiment, but differs in the following points.

In step (2) of Example 1, the resin containing low-density polyethylene was not mixed, and the resin containing an olefin polymer having a cyclic structure was used in the following ratio.
COC resin 1 (Polyplastics TOPAS (TM)) 70 parts by mass COC resin 2 (Polyplastics TOPAS (TB)) 30 parts by mass About each toner particle obtained in the above examples and comparative examples, The evaluation described below was performed. The evaluation results are shown in Table 1.

<Comparative Example 3>
This comparative example basically conforms to the first embodiment, but differs in the following points.

In step (2) of Example 1, a low-density polyethylene wax having a lower molecular weight is used in place of the resin containing low-density polyethylene, and the resin containing the olefin polymer having a cyclic structure and the wax are used. Changed to use at the following ratio.
COC resin (Polyplastics TOPAS (TM)) 70 parts by mass Low-density polyethylene wax (Mitsui Chemicals high wax NL500: density 0.920 g / cm ³ , weight average molecular weight (Mw): 4200) 30 parts by mass

<Evaluation items>
(Evaluation of transfer efficiency)
The transfer efficiency is a transferability index indicating how much the toner developed on the photosensitive drum is transferred onto the intermediate transfer belt. The transfer efficiency was evaluated by filling the toner of the present invention in a drum cartridge of a full-color electrophotographic apparatus (manufactured by Canon: LBP-5050) and continuously forming a solid cyan image on a recording medium. Toner on the intermediate transfer belt when the sum of the density of the toner transferred on the intermediate transfer belt after the formation of 3000 images and the density of the toner remaining on the photosensitive drum after transfer is 100% The density ratio was defined as transfer efficiency. The higher this ratio, the better the transfer efficiency after endurance. In the present invention, the evaluation of transfer efficiency was judged according to the following criteria.
A: Very good (transfer efficiency is 98% or more)
B: Good (transfer efficiency is 95% or more and less than 98%)
C: Practical use possible (transfer efficiency 90% or more and less than 95%)
D: Inferior (transfer efficiency is less than 90%)
If the transfer efficiency was 95% or more, it was judged that the transfer efficiency was good.

(Minimum fixing temperature evaluation)
The image forming apparatus is adjusted in advance so that the toner amount on the recording paper before fixing at the time of solid image printing is 0.6 mg / cm ² . After the adjustment, a solid image was printed under conditions of 21 points every 5 ° C. from 100 ° C. to 200 ° C., and the obtained images were subjected to an offset image test and a fixability test.

  In determining the fixing temperature, there is a hot offset limit temperature on the high temperature side, and when this temperature is exceeded, a hot offset phenomenon occurs. On the contrary, the lower temperature side has a fixing limit temperature, and below this temperature, fixing failure occurs.

The fixability limit temperature was set as the minimum fixing temperature, and the low temperature fixability index was ranked as follows.
A: Minimum fixing temperature is 130 ° C. or lower B: Minimum fixing temperature is higher than 130 ° C., 140 ° C. or lower C: Minimum fixing temperature is higher than 140 ° C., 150 ° C. or lower D: Minimum fixing temperature is higher than 150 ° C., 160 ° C. Hereinafter, E: Minimum fixing temperature exceeds 160 ° C. If the minimum fixing temperature is 150 ° C. or less, it was judged that the low temperature fixing property was good.

<About evaluation results>
Examples 1 to 7 show examples that well represent the effects of the configuration of the present invention.

That is, in Examples 1 to 7, as described above, the resin on the surface of each toner particle contains an olefin copolymer having a cyclic structure and polyethylene, and the density of the polyethylene is 0.930 g / cm ^3. The toner was manufactured so that the molecular weight of the polyethylene was in the range of 10,000 to several million.

  This makes it possible to suppress the burying performance of the external additive on the toner surface. In addition, since the resin that forms the toner surface contains an olefin copolymer having a cyclic structure and polyethylene, the toner surface can be reduced in moisture absorption and has charging stability regardless of the environment. Throughout durability, it is a toner with little transfer residue.

  On the other hand, in Comparative Examples 1 and 2, the toner is manufactured so that the resin on the toner surface is a resin containing an olefin-based copolymer having a cyclic structure, and the polyethylene is not included. In addition, the high elastic deformation performance of low density polyethylene cannot be imparted to the toner surface, and the plastic deformation resistance of the toner surface cannot be obtained. It is thought that it has been.

  Further, Comparative Example 3 shows an example using polyethylene wax in which the molecular weight of low-density polyethylene is less than 10,000. However, if the molecular weight of polyethylene is too small relative to the molecular weight of the resin on the toner surface, low-density polyethylene is used. It is considered that the chain transfer property of the toner cannot be obtained, that is, high elastic deformation performance as a resin on the toner surface cannot be obtained, and as a result of the external additive being buried, the transfer residue is deteriorated.

  In Examples 8 to 11, as described above, the toner was manufactured such that the content of the resin on the toner surface was smaller than that of polyethylene in the olefin copolymer having a cyclic structure. The minimum fixing temperature tends to be higher than that of the toners of Examples 1-7. This is considered to be due to the fact that the melting property of the resin on the toner surface is made higher in viscosity because the olefin copolymer having a cyclic structure is less than the low density polyethylene.

  In the present invention, the ratio of polyethylene contained in the resin on the toner surface is defined. However, the polyethylene content of the toner as a whole is less than 3% of the whole toner. From the viewpoint of fixability, it is more preferable.

  As shown in Examples 12 and 13, the content ratio of the resin on the toner surface is larger in the olefin copolymer having a cyclic structure than in the polyethylene, but the polyethylene ratio as a whole of the toner exceeds 3%. Although the transfer performance is good, the minimum fixing temperature is slightly increased.

  Further, if the total amount of the resin including the olefin copolymer having a cyclic structure and the low density polyethylene as the resin on the toner surface is extremely reduced, the effect of the present invention is diminished. It is preferable to contain 0.5% or more, and it is more preferable to contain 3% or more.

  In Example 14, the total amount of the resin including the olefin copolymer having a cyclic structure and the low density polyethylene as the resin on the toner surface is approximately 0.5%. The effect of the additive burying resistance is less than that of Examples 1 to 13, and the fog and transfer residue are slightly lower than the toners of other examples.

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging roller 3 Laser optical apparatus 4 Developing apparatus 5 Primary transfer apparatus 6 Intermediate transfer body 7 Secondary transfer apparatus 8 Paper 9 Cleaning blade 10 Fixing apparatus 11 Cartridge 12 Toner 13 Developing container 14 Developing roller 14a Core metal electrode 14b Elasticity Layer 15 Supply roller 15a Core metal electrode 15b Urethane foam layer 16 Regulating blade

Claims (2)

A toner having a surface composition comprising an olefin copolymer having a cyclic structure and polyethylene,
The toner has a density of less than 0.930 g / cm ³ and a weight average molecular weight of 10,000 to 5,000,000.   2. The toner according to claim 1, wherein the olefin-based copolymer having the cyclic structure is more than the polyethylene with respect to a presence ratio on the toner surface.

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