JP2005173065A - Toner for electrostatic charge image development and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner for electrostatic charge image development for non-magnetic one-component development by which a wide non-offset temperature region can be obtained even at the time of high-speed printing and further, there are no dislodgment and leakage from a developing device, such as a developing roller, even in development processing for a long time, the contamination within the image forming apparatus can be suppressed and images of high sharpness free of image density unevenness can be obtained and an image forming method. <P>SOLUTION: The toner for electrostatic charge image development used for non-magnetic one-component development is obtained by an emulsion polymerization condensation method and is so composed that the coverage of an external additive particulate determined by equation (A) attains ≤300%. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electrostatic image developing toner and an image forming method. More specifically, high-speed printing is possible when used for development by an image forming apparatus such as a non-magnetic one-component copying machine or printer, and further, from a developing device such as a developing roller even during long-time development processing. The present invention relates to a toner for developing an electrostatic charge image and an image forming method capable of suppressing contamination in an image forming apparatus without dropping off or leaking and obtaining a high-quality image without image density unevenness.

In recent years, electrophotographic technology has been widely used not only in the field of copying machines but also in various printer fields in terms of immediacy and high image quality.
In general, a visible image is formed by electrophotography by first forming an electrostatic latent image on a photosensitive drum, then developing it with toner, transferring it to transfer paper, and fixing it with heat or the like. The As a developing method at this time, a two-component developing method using a mixture of a carrier and a toner or a one-component developing method not using a carrier is generally used. Of these, the two-component development method requires a so-called toner density control mechanism that replenishes the required amount as the toner is consumed, and thus has a problem in terms of size and cost of the apparatus. For this reason, with the recent increase in personal printers and full-color printers, an increasing number of apparatuses adopt a one-component development system, particularly a non-magnetic one-component development system, which can reduce the size of the apparatus.

  On the other hand, in recent years, there has been an increase in image quality as a performance that copiers and printers should have, and in order to achieve this, a toner having a small particle size and a narrow particle size distribution is required. In the kneading and pulverization method, it is difficult to obtain such a toner with a high yield. As a method for improving such a problem, a toner by a suspension polymerization method or an emulsion polymerization aggregation method has been proposed. These production methods called polymerization methods make it easy to control the particle size of the toner, so that a toner having a small particle size and a narrow particle size distribution can be obtained. Furthermore, since there is no pulverization step, a binder resin with a low softening point is used. Therefore, the low-temperature fixability can also be improved.

When such a suspension polymerization method or emulsion polymerization aggregation toner is used for the above-mentioned non-magnetic one-component development, the surface of the toner base particles obtained by the suspension polymerization method or emulsion polymerization aggregation method is usually used. A material to which externally added fine particles are attached is used (for example, see Patent Document 1). In the case of the non-magnetic one-component development method, it is necessary to charge the toner supplied on the developing roller by contact with a layer thickness regulating blade or the like, and it is necessary to maintain a sufficient charge amount by the externally added fine particles. Because. In particular, toner mother particles obtained by the emulsion polymerization aggregation method have a lower circularity than toner mother particles obtained by the suspension polymerization method. Therefore, in order to ensure a stable charge amount and fluidity, it is conventionally necessary to add external additives at a high coverage. There was a need to attach fine particles.
JP-A-9-325516.

  On the other hand, in recent years, higher-speed printability has been demanded, and to achieve this, further improvements in low-temperature fixability and offset resistance have been demanded on the toner, but this has still reached a sufficient level. The current situation is not. In particular, when trying to improve the low-temperature fixability, if a large amount of externally added fine particles are present, it becomes difficult to quickly melt (soften) or fix the toner, which is compatible with ensuring the above stable charge amount and fluidity. It was difficult. In addition, with the increase in printing speed, new problems such as remarkable toner leakage from the developing device have occurred, and in this way, a non-magnetic one-component developing toner suitable for high-speed printing can be obtained. It wasn't clear whether it was possible.

  The present invention has been made in view of the above-described prior art. Accordingly, the present invention is capable of high-speed printing, and further, even during long-time development processing, the developer roller or the like is not dropped or leaked. An object of the present invention is to provide an electrostatic charge image developing toner for non-magnetic one-component development and an image forming method capable of suppressing contamination in the image forming apparatus and obtaining a high-quality image without image density unevenness. .

  As a result of intensive studies to solve the above problems, the present inventor has unexpectedly found that a toner formed by attaching externally added fine particles at a low coverage compared with a conventionally used toner for non-magnetic one-component development. In addition, the inventors have found that high-speed printability is good and have completed the present invention. That is, one of the gist of the present invention is an electrostatic image developing toner used for non-magnetic one-component development, the toner obtained by an emulsion polymerization aggregation method, and the following formula (A) The toner for developing an electrostatic charge image is characterized in that the coverage of the externally added fine particles obtained in (1) is 300% or less.

Dt: Average particle diameter of toner base particles (μm)
ρt: True density of toner base particles (g / cm ³ )
Dn: average particle diameter of externally added fine particles n (μm)
ρn: true density of externally added fine particles n (g / cm ³ )
Wn: number of added external fine particles n (parts by weight based on 100 parts by weight of toner base particles)
a: Number of types of externally added fine particles.

  In addition, as a result of intensive studies to solve the above problem, the present inventor uses a layer thickness regulating member and / or a developing roller that uses the toner and has a material having a specific charging property as an outermost layer. According to the image forming method, the high-speed printability is good, and there is no dropout or leakage from the developing device such as the developing roller even in the long-time development processing, and the contamination in the image forming device can be suppressed and the image density can be suppressed. The present inventors have found that high-quality images without unevenness can be obtained, and have completed the present invention. That is, another aspect of the present invention is a non-magnetic one-component image forming method using the toner for developing an electrostatic charge image as a developer, a layer thickness regulating member constituting the image forming apparatus, and The image forming method is characterized in that at least one of the outermost layers of the developing roller is a material having a charging property on the positive side in relation to a charged row as compared with polyurethane.

  According to the present invention, a wide non-offset temperature range can be obtained even during high-speed printing, and further, there is no dropout or leakage from the developing device such as a developing roller even during long-time development processing, thereby suppressing contamination in the image forming apparatus. In addition, it is possible to provide an electrostatic charge image developing toner for non-magnetic one-component development and an image forming method capable of obtaining a high-quality image free from uneven image density.

Hereinafter, the electrostatic image developing toner and the image forming method of the present invention will be described in detail.
The toner for developing an electrostatic image of the present invention is obtained by externally adding fine particles added to the surface of toner base particles obtained by an emulsion polymerization aggregation method.
In the present invention, the emulsion polymerization aggregation method means a production method having a step of aggregating an emulsion containing at least polymer primary particles obtained by the emulsion polymerization method. In the emulsion polymerization aggregation method, usually, a polymerizable monomer constituting the polymer primary particles is emulsified in an aqueous medium containing a polymerization initiator and an emulsifier, and the polymerizable monomer is polymerized with stirring, and then the polymer is first polymerized. An emulsion of primary particles is produced, and then a colorant and, if necessary, a charge control agent, a release agent, and the like are added to the obtained polymer primary particle emulsion to aggregate the polymer primary particles. It is produced as an aggregate, and further, the primary particle aggregate is aged by heating.

  The polymerizable monomer constituting the polymer primary particle is not limited, and examples thereof include styrene, methylstyrene, chlorostyrene, dichlorostyrene, p-tert-butylstyrene, pn-butylstyrene, and pn-nonylstyrene. Styrenes, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, ethyl hexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-methacrylic acid n- (Meth) acrylic acid esters such as butyl, isobutyl methacrylate, hydroxyethyl methacrylate, ethylhexyl methacrylate, acrylamide, N-propylacrylamide, N, N-dimethylacrylamide, N, N-dipropylacrylate Ruamido, N, N-dibutyl acrylamide, acrylic acid amide, and the like. Among these styrene, butyl acrylate are particularly preferred. These monomers may be used alone or in combination.

  In addition, the polymerizable monomer constituting the polymer primary particles may be a monomer having a Bronsted acidic group (hereinafter sometimes simply referred to as an acidic monomer) and / or a Bronsted base together with or in place of the monomer. It is also preferable to use a monomer having a functional group (hereinafter sometimes simply referred to as a basic monomer) as a raw material monomer. Examples of acidic monomers include monomers having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and cinnamic acid, monomers having a sulfonic acid group such as sulfonated styrene, and sulfonamide groups such as vinylbenzenesulfonamide. And the like. In addition, as the basic monomer, an aromatic vinyl compound having an amino group such as aminostyrene, a nitrogen-containing heterocyclic ring-containing monomer such as vinylpyridine or vinylpyrrolidone, or an amino group such as dimethylaminoethyl acrylate or diethylaminoethyl methacrylate ( And (meth) acrylic acid esters. These acidic monomers and basic monomers may be used alone or in combination, and may exist as a salt with a counter ion.

  When an acidic monomer or a basic monomer is used as the monomer constituting the polymer primary particles, the total amount of the acidic monomer and the basic monomer is preferably 0.00 with respect to 100 parts by weight of the total monomers constituting the polymer primary particles. It is desirable that the amount is not less than 05 parts by weight, more preferably not less than 0.5 parts by weight, still more preferably not less than 1 part by weight, preferably not more than 10 parts by weight, more preferably not more than 5 parts by weight. Thus, by using an acidic monomer or a basic monomer, the dispersion stability of the polymer primary particles may be improved.

Furthermore, a polyfunctional monomer can also be used as a monomer constituting the polymer primary particles. Examples of the multifunctional monomer include divinylbenzene, hexanediol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol acrylate, diallyl phthalate, and the like. It is also possible to use monomers having a reactive group in the pendant group, such as glycidyl methacrylate, methylol acrylamide, acrolein and the like. Of these, radical polymerizable bifunctional monomers are preferable, and divinylbenzene and hexanediol diacrylate are particularly preferable. These polyfunctional monomers may be used alone or in combination.

  When a polyfunctional monomer is used as the monomer constituting the polymer primary particles, the content thereof is preferably 0.005 parts by weight or more, more preferably 100 parts by weight or more based on the total monomers constituting the polymer primary particles. It is desirable that it is 0.1 parts by weight or more, more preferably 0.3 parts by weight or more, preferably 5 parts by weight or less, more preferably 3 parts by weight or less, and still more preferably 1 part by weight or less. By using a polyfunctional monomer in this way, the fixability may be improved.

  Examples of the polymerization initiator include persulfates such as sodium persulfate and ammonium persulfate, organic peroxides such as t-butyl hydroperoxide, cumene hydroperoxide, and p-menthane hydroperoxide, hydrogen peroxide, and the like. One or two or more inorganic peroxides are usually used in an amount of 0.05 to 2 parts by weight based on 100 parts by weight of the polymerizable monomer. Of these, inorganic peroxides are preferred as the polymerization initiator. In addition, these polymerization initiators may be one of reducing agents such as reducing organic compounds such as ascorbic acid, tartaric acid and citric acid, and reducing inorganic compounds such as sodium thiosulfate, sodium bisulfite and sodium metabisulfite. It can also be set as the redox type | system | group initiator which used 2 or more types together.

Moreover, a well-known chain transfer agent can also be used as needed, Specifically, t-dodecyl mercaptan, 2-mercaptoethanol, diisopropyl xanthogen, carbon tetrachloride, trichlorobromomethane, etc. are mentioned. The chain transfer agent may be used alone or in combination of two or more, and is usually used in the range of 5% by weight or less based on the total monomers.
As the emulsifier, nonionic, anionic, cationic and amphoteric surfactants are usually used. Examples of the nonionic surfactant include polyoxyalkylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyalkylene alkyl phenyl ethers such as polyoxyethylene octylphenyl ether, and sorbitan fatty acid esters such as sorbitan monolaurate. Examples of the anionic surfactant include fatty acid salts such as sodium stearate and sodium oleate, alkylaryl sulfonates such as sodium dodecylbenzene sulfonate, and alkyl sulfate salts such as sodium lauryl sulfate. Examples of the cationic surfactant include amphoteric surfactants such as alkylamines such as laurylamine acetate, and quaternary ammonium salts such as lauryltrimethylammonium chloride. Is, for example, alkyl betaines such as lauryl betaine, and the like, or these one or two is used. Of these, nonionic surfactants and anionic surfactants are preferred. The amount used as an emulsifier is usually 1 to 10 parts by weight with respect to 100 parts by weight of the polymerizable monomer, and these emulsifiers include, for example, partially or fully saponified polyvinyl alcohols such as saponified polyvinyl alcohol, hydroxyethyl cellulose. 1 type, or 2 or more types, such as cellulose derivatives, etc. can be used together as a protective colloid.

In addition, the addition of the polymerizable monomer to the reaction system in the emulsion polymerization may be any of batch addition, continuous addition, and intermittent addition, but from the viewpoint of reaction control, continuous addition is preferable. Moreover, when using a some monomer, the addition of each monomer may be added separately, or a plurality of monomers may be mixed and added simultaneously. Furthermore, it is possible to change the monomer composition during the monomer addition. The addition of the emulsifier to the reaction system may be any of batch addition, continuous addition, and intermittent addition. In addition to the emulsifier and the polymerization initiator, a pH adjuster, a polymerization degree adjuster, an antifoaming agent, and the like can be appropriately added to the reaction system.

The polymer primary particles in the present invention can be used in combination with a plurality of different polymer primary particles obtained as described above.
The polymer primary particles in the present invention can be used in combination with particles obtained by the above-described emulsion polymerization and particles obtained by other polymerization methods. Examples of such particles include, in addition to particles having the same composition as that obtained by emulsion polymerization, vinyl monomers such as vinyl acetate, vinyl chloride, vinyl alcohol, vinyl butyral, and vinyl pyrrolidone. Homopolymers or copolymers, saturated polyester resins, polycarbonate resins, polyamide resins, polyolefin resins, polyarylate resins, polysulfone resins, polyphenylene ether resins, and other thermoplastic resins, and unsaturated polyester resins, phenol resins, epoxy resins, Examples thereof include particles made of a thermosetting resin such as a urethane resin and a rosin-modified maleic resin, and two or more of these may be used in combination.

  The volume average particle size of the polymer primary particles in the present invention is usually 0.02 μm or more, preferably 0.05 μm or more, more preferably 0.1 μm or more, usually 3 μm or less, preferably 2 μm or less, more preferably 1 μm. The following is desirable. The volume average particle diameter can be measured using, for example, Nikkiso Microtrac UPA. When the particle size is less than the above range, it may be difficult to control the aggregation rate. When the particle size exceeds the above range, the particle size of the toner obtained by aggregation tends to be large, and a toner having a target particle size can be obtained. It can be difficult.

  The polymer primary particles in the present invention preferably have a glass transition temperature of 40 ° C. or higher, more preferably 50 ° C. or higher, preferably 80 ° C. or lower, more preferably 70 ° C. or lower. When the glass transition temperature is within the above range, it is desirable because the storage stability and fixing property of the toner are improved. Here, the Tg of the binder resin draws a tangent to the start of transition (inflection) of the curve measured on the differential scanning calorimeter (DTA-40 manufactured by Shimadzu Corporation) under the condition of a temperature rising rate of 10 ° C./min. It can be determined as the temperature of the intersection of two tangents.

  Further, the polymer primary particles in the present invention have at least one of peak molecular weights in gel permeation chromatography, preferably 3000 or more, more preferably 10,000 or more, further preferably 30,000 or more, preferably 100,000. In the following, it is desirable to be present at 70,000 or less, more preferably 60,000 or less. When the peak molecular weight is in the above range, it is desirable because the durability, storage stability, and fixability of the toner are improved. Here, as the peak molecular weight, a value converted to polystyrene is used, and components insoluble in a solvent are excluded in measurement.

  The colorant in the present invention is not limited, and various inorganic and organic dyes and pigments generally used as a colorant for toner are used. Specifically, for example, iron powder, copper Metal powders such as powder, metal oxides such as Bengala, inorganic pigments such as carbon represented by carbon black such as furnace black and lamp black, azo series such as benzidine yellow and benzidine orange, quinoline yellow, acid green, Precipitation with a precipitating agent of dyes such as alkali blue, acid dyes such as rhodamine, magenta, and macalite green dyes such as tannic acid and phosphomolybdic acid, basic dyes, and mordanting of metal salts of hydroxyanthraquinones Dyes, phthalocyanine blue, phthalocyanine-based phthalocyanine such as copper phthalocyanine sulfonate, quinac Organic pigments such as quinacridone and dioxane, such as Don Red and Quinacridone Violet, synthetic dyes such as aniline black, azo dye, naphthoquinone dye, indigo dye, nigrosine dye, phthalocyanine dye, polymethine dye, di- and triallylmethane dye These may be used in combination of two or more.

The content of the colorant is preferably 1 to 20 parts by weight, more preferably 2 to 15 parts by weight with respect to 100 parts by weight of the polymer primary particles.
Although the toner of the present invention is a toner for non-magnetic one-component development, a magnetic colorant may be used as long as the characteristics are not lost. Examples of the magnetic colorant include a ferromagnetic material exhibiting ferrimagnetism or ferromagnetism in the vicinity of 0 to 60 ° C., which is the use environment temperature of a copying machine, such as magnetite (Fe ₃ O ₄ ), maghematite ( γ-Fe ₂ O ₃ ), intermediates and mixtures of magnetite and maghematite, ferrite (M _x Fe _{3 -x} O ₄ ; where M is Mg, Mn, Fe, Co, Ni, Cu, Zn, Cd Spinel ferrite such as BaO · 6Fe ₂ O ₃ , hexagonal ferrite such as SrO · 6Fe ₂ O ₃ , garnet type oxide such as Y ₃ Fe ₅ O ₁₂ and Sm ₃ Fe ₅ O ₁₂ , CrO ₂ etc. Rutile oxide and Cr, Mn, F
Among the metals such as e, Co, Ni, and their ferromagnetic alloys, those exhibiting magnetism in the vicinity of 0 to 60 ° C. may be mentioned, and among these, magnetite is preferable. When it is added from the viewpoint of scattering prevention, charge control, etc. while having the characteristics as a non-magnetic toner, the addition amount is 0.1 to 10 parts by weight, preferably 0, per 100 parts by weight of the polymer primary particles. .2-8 parts by weight, more preferably 0.5-5 parts by weight.

  The toner for developing an electrostatic charge image of the present invention may contain a charge control agent, and as the charge control agent, for example, a conventionally known nigrosine dye, quaternary ammonium salt compound, triphenylmethane, and the like. Compounds, imidazole compounds, positive charge control agents such as polyamine resins, or metal-containing azo dyes such as chromium, cobalt, aluminum and iron, metal salts such as chromium, zinc and aluminum of salicylic acid or alkylsalicylic acid And negatively charged charge control agents such as metal salts and metal complexes of benzylic acid, amide compounds, phenolic compounds, naphthol compounds, and phenolamide compounds, and two or more of these may be used in combination.

In addition, it is preferable that the content rate of the said charge control agent is 0.01-10 weight part with respect to 100 weight part of said polymer primary particles, and it is still more preferable that it is 0.1-5 weight part.
In addition, the toner for developing an electrostatic image of the present invention preferably further contains a release agent for improving the releasability at the time of fixing to a transfer material, and as the release agent, Conventionally known, for example, low molecular weight polyethylene, low molecular weight polypropylene, polyolefin wax such as low molecular weight ethylene-propylene copolymer, fluororesin wax such as low molecular weight polytetrafluoroethylene, paraffin wax, stearic acid ester, behen Ester waxes having long chain aliphatic groups such as acid esters and montanate esters, plant waxes such as hydrogenated castor oil and carnauba wax, ketones having long chain alkyl groups such as distearyl ketone, silicones having alkyl groups , Higher fatty acids such as stearic acid, long chain fatty alcohols, pentaerythritol, etc. and long chain fats (Partial) ester of an acid amide, oleic acid, waxes such as higher fatty acid amides such as stearic acid amide and the like, may be used in combination of two or more of these. In the present invention, these releasing agents preferably have a melting point of 50 to 100 ° C. from the viewpoint of low temperature fixing and high speed fixing.

The content of the release agent is preferably 0.1 to 30 parts by weight, more preferably 5 to 25 parts by weight with respect to 100 parts by weight of the polymerizable primary particles.
In addition, the said mold release agent can also manufacture the polymeric primary particle containing a mold release agent by carrying out seed polymerization using it as a seed in the emulsion polymerization of the said polymerizable monomer.
Further, in the present invention, the toner particles include various known internal additives for modifying the adhesiveness, cohesiveness, fluidity, chargeability, surface resistance, etc. of the toner, such as silicone oil and silicone varnish. May be contained. These can be added internally to the toner particles by adding at the time of aggregation, but are preferably contained in the polymer primary particles in advance.

The production of toner particles by the emulsion polymerization aggregation method is performed by adding a colorant and, if necessary, additives such as a charge control agent and a release agent to the emulsion of the polymer primary particles obtained by the emulsion polymerization. Next, while stirring and mixing with a disperser, a mixer, etc., the dispersion stability of the polymer primary particles as an emulsion is reduced, for example, heating, addition of electrolyte, pH adjustment, addition of a curing agent, etc. Then, the aggregate is formed into an aggregate, and then the primary particles in the aggregate are aged (fused) and stabilized by heat treatment.

As an electrolyte in the case of performing aggregation by adding an electrolyte, either an organic salt or an inorganic salt may be used. Specifically, NaCl, KCl, LiCl, Na ₂ SO ₄ , K ₂ SO ₄ , Li ₂ SO ₄ , _{MgCl 2, CaCl 2, MgSO 4} , CaSO 4, ZnSO 4, Al 2 (SO 4) 3, Fe 2 (SO 4) 3, CH 3 COONa, C 6 H 5 SO 3 Na and the like. Of these, inorganic salts having a divalent or higher polyvalent metal cation are preferred. The amount of the electrolyte to be added varies depending on the type of the electrolyte, but is usually 0.05 to 25 parts by weight, preferably 0.1 to 15 parts by weight, and more preferably 0.8 to 100 parts by weight of the solid component of the mixed dispersion. 1 to 10 parts by weight. When the electrolyte is added and the amount of electrolyte added is less than the above range, the progress of the agglomeration reaction is slow, and a fine powder of 1 μm or less remains after the agglomeration reaction, or the average of the obtained particle aggregates If the particle size does not reach the target particle size, the particle size may exceed the above range. If the particle size exceeds the above range, rapid aggregation tends to occur, making it difficult to control the particle size. There are cases where problems such as the inclusion of indeterminate items. In addition, 20-40 degreeC is preferable and the aggregation temperature in the case of performing an aggregation by adding electrolyte has more preferable 25-35 degreeC.

  The heating temperature at the time of fusing and stabilizing the primary particles in the aggregate is preferably not less than the glass transition temperature of the polymer constituting the primary particles, more preferably not less than 5 ° C. higher than the glass transition temperature. Moreover, the temperature below 80 degreeC higher than the glass transition temperature of a polymer is preferable, and the temperature below 50 degreeC is still more preferable. The heating time is preferably 1 to 6 hours. By such heat treatment, the primary particles in the aggregate are fused and integrated, and the shape of the toner particles as the aggregate is also nearly spherical.

  Further, the surface of the toner particles as an aged product obtained by the emulsion polymerization aggregation method described above is further subjected to a polymer mainly by a method such as a spray drying method, an in-situ method, or a submerged particle coating method. Encapsulated toner particles can also be formed by forming the outer layer as a component with a thickness of preferably 0.01 to 0.5 μm. The glass transition temperature of the polymer used for the outer layer in the encapsulated toner particles is preferably 70 to 110 ° C., and preferably higher than the glass transition temperature of the polymer primary particles.

The average particle diameter of the toner base particles thus obtained is usually 3 to 15 μm, preferably 4 to 10 μm. Here, the particle size of the toner base particles is a value measured using a multisizer (manufactured by Coulter).
The toner for developing an electrostatic charge image of the present invention comprises toner particles as particles obtained by the emulsion polymerization aggregation method, and contains externally added fine particles on the surface of the toner mother particles.

As the externally added fine particles used in the present invention, known inorganic and organic fine particles can be used, which may be negatively charged or positively charged, and these may be used in combination. The toner is preferably used so that the chargeability as a toner is negatively charged. Among these, at least one kind of negatively chargeable externally added fine particles is preferable.
Examples of negatively charged externally added fine particles include metal oxides and hydroxides such as alumina, silica, titania, zinc oxide, zirconium oxide, cerium oxide, talc, hydrotalcite, calcium titanate, strontium titanate, Acrylic acid containing inorganic fine particles such as metal titanate such as barium titanate, nitrides such as titanium nitride and silicon nitride, carbides such as titanium carbide and silicon carbide, and acrylic acid and its derivatives as main components Negatively chargeable organic fine particles such as methacrylic resin, methacrylic acid resin having methacrylic acid and its derivatives as the main monomer, tetrafluoroethylene resin, trifluoroethylene resin, polyvinyl chloride, polyethylene, polyacrylonitrile, etc. It is done. Among the inorganic fine particles, silica, titania, and alumina are preferable, and those treated with a silane coupling agent or silicone oil are more preferable. As the organic fine particles, acrylic acid resins such as polymethyl acrylate and methacrylic acid resins such as polymethyl methacrylate are preferable, and polymethyl methacrylate is particularly preferable.

Examples of the positively charged externally added fine particles include calcium phosphate compounds such as tricalcium phosphate, calcium dihydrogen phosphate, calcium monohydrogen phosphate, substituted calcium phosphate in which a part of phosphate ion is substituted by an anion, and Examples thereof include those whose surfaces have been subjected to a hydrophobic treatment with fatty acids and the like, surface-treated silica such as aminosilane-treated silica, and alumina.
The externally added fine particles preferably have an average particle diameter of preferably 0.001 μm or more, more preferably 0.005 μm or more, preferably 1 μm or less, more preferably 0.5 μm or less. Further, a plurality of externally added fine particles having different materials and different average particle diameters can be blended. Here, as the average particle diameter of the externally added fine particles, a value converted from the specific surface area value measured by the BET method as the particle diameter when the particles are assumed to be spherical is used.

  The present invention is characterized in that the coverage of the externally added fine particles on the surface of the toner base particles is controlled. In the present invention, the coverage of the externally added fine particles is 300% or less, preferably 295% or less, as a value determined by the following formula (A). The lower limit of the coverage is usually 10% or more, preferably 50% or more, more preferably 100% or more.

Dt: Average particle diameter of toner base particles (μm)
ρt: True density of toner base particles (g / cm ³ )
Dn: average particle diameter of externally added fine particles n (μm)
ρn: true density of externally added fine particles n (g / cm ³ )
Wn: number of added external fine particles n (parts by weight based on 100 parts by weight of toner base particles)
a: Number of types of externally added fine particles.

Here, the true density (ρt) of the toner base particles and the true density (ρn) of the externally added fine particles n are obtained by appropriately selecting from general density measurement methods such as a differential pressure type, a floatation type, and an immersion type, for example. Can do.
By attaching the externally added fine particles to the surface of the toner particles at such a covering rate, the low-temperature fixing property and the offset resistance are improved in non-magnetic one-component development, and high-speed printing becomes possible. Although this mechanism is not clear, it is presumed that if the coverage of the externally added fine particles is within the above range, the externally added fine particles do not physically hinder the adhesion between the melted toner and the printing paper. Further, by not attaching an excessive amount of externally added fine particles, it is possible to suppress a decrease in the conduction efficiency of the heat received by the toner from the heating roller during fixing, so that the toner can be melted quickly, for example, the printing speed is 100 mm / It is considered that fixing can be suitably performed even under high-speed printing conditions such as 200 seconds / sec or more. Further, when the coverage of the externally added fine particles is less than the above range, image defects such as blurring of a solid image may occur due to deterioration of toner fluidity. Here, the coverage of the externally added fine particles does not mean only the externally added fine particles attached to the surface of the toner particles, but the externally added fine particles that are not attached and exist independently, or the surface of the toner particles. It also includes externally added fine particles buried in the vicinity. When the sphericity of the externally added fine particles is low, the externally added fine particles can cover the surface of the toner base particles even when the coverage exceeds 100%.

In the present invention, the method for blending (attaching) the external additive fine particles on the surface of the toner base particles is not limited, and a mixer generally used for toner production can be used. For example, a Henschel mixer, a V-type blender, etc. , By uniformly stirring and mixing with a mixer such as a Redige mixer.
The circularity of the toner for developing an electrostatic charge image of the present invention thus obtained is not limited, but in the present invention, HPF is obtained using a flow type particle image analyzer FPIA-2100 (manufactured by Sysmex Corporation (formerly Toa Medical Electronics)). The average circularity calculated when measured in the mode is preferably 0.92 or more, more preferably 0.94 or more, preferably 0.99 or less, more preferably 0.98 or less. . If the circularity is less than the above range, the transfer efficiency may be poor and the dot reproducibility may decrease, and if the circularity exceeds the above range, the untransferred toner remaining on the photoreceptor may not be completely scraped off by the blade and cause image defects. There is.

  Further, the chargeability of the toner for developing an electrostatic charge image of the present invention is not limited, but a negatively chargeable developer is desirable, and the charge amount at 23 ° C. and 50% relative humidity is preferably −10 μC / g or less. More preferably, it is −20 μC / g or less, preferably −90 μC / g or more, more preferably −70 μC / g or more. When the toner for developing an electrostatic charge image of the present invention has a charge amount in the above range, it is preferable because the image quality is high with less fog. The charge amount of the toner can be adjusted by the resin as the main component of the developer, the charge control agent added as necessary, the selection of the external additive fine particles, and the blending ratio, blending method or adhesion method. It is effective to select the externally added fine particles and optimize the adhesion amount. In the present invention, the toner charge amount is measured by first weighing 19.2 g of a non-coated ferrite carrier (P100 manufactured by Powdertech) and 0.8 g of particles to be measured, and stirring for 5 minutes with a reciprocating shaker (stir strength 500 rpm). ) And then measured with a blow-off measuring device (manufactured by Toshiba Chemical).

  The electrostatic image developing toner of the present invention can be used for any of black toner, color toner, and full color toner, but when used as a color toner or full color toner, the effects of the present invention can be exhibited more remarkably. The electrostatic charge image developing toner of the present invention exhibits the effect of the present application remarkably when used as a developer for performing non-magnetic one-component development, but two-component development using a carrier. It can also be used as an agent.

Hereinafter, the image forming method of the present invention will be described in detail.
In the image forming method of the present invention, non-magnetic one-component development is performed using the toner for developing an electrostatic charge image as a developer. The developing device used in the present invention is generally composed of a member selected from a toner supply roller, a layer thickness regulating member, a developing roller, a toner stirring member, and the like, and the electrostatic charge image developing toner of the present invention. Further, the developing device in the present invention is preferably a cartridge type.

When performing non-magnetic one-component development, the layer thickness of the developer on the developing roller is usually regulated by a layer thickness regulating member, and the developer and the layer thickness regulating member at this time are brought into contact friction so that the developer Charge. Note that the layer thickness regulating member may be a member that presses the developing roller or a non-contact member, but the member that presses the developing roller efficiently charges the developer. This is preferable. In addition, the developing roller of the present invention may be used in a developing system that is not in contact with the photosensitive member or in a developing system that is in contact with the photosensitive member, but the contact system is preferable in terms of increasing the development efficiency.

  In the image forming method of the present invention, the outermost layer of at least one of the layer thickness regulating member and the developing roller constituting the image forming apparatus is made of a material having a plus-side chargeability in relation to the charged column rather than polyurethane. Is used. Such a material is not limited as long as it is a material having a positive chargeability in relation to a charged column as compared with polyurethane. For example, polyamide resin, polyamide-based thermoplastic elastomer, silicone resin, silicone rubber Glass, etc. Among them, polyamide resin, silicon resin, and silicon rubber are preferable, and polyamide resin is particularly preferable. By using a material having such characteristics for the layer thickness regulating member or the outermost layer of the developing roller, high-speed printing is possible in the non-magnetic one-component development. There is no dropout or leakage, and contamination in the image forming apparatus can be suppressed. As the manifestation mechanism, by using a positive side of the polyurethane in relation to the charge train, high negative chargeability is imparted to the negatively charged developer, and the developer is held on the developing roller by mirror image force. Presumed to be. For this reason, in particular, when the toner for developing an electrostatic charge image of the present invention in which the amount of externally added fine particles is less than usual is developed as described above, good development can be performed.

  Here, the polyurethane used as a standard for charging in the present invention usually means a polyurethane used for a layer thickness regulating member and a developing roller in a commercially available non-magnetic one-component developing device. If the standard is unclear because the chargeability is not constant, E580 (thermoplastic polyurethane, JIS-A hardness 80) manufactured by Nippon Milactolan, or methylene diphenyl diisocyanate (MDI) / polycaprolactone (number average molecular weight 2000) / 1,4-butanediol = 3/2/1 (mol ratio), and a JIS-A hardness of 75 to 80 is used as a reference. In addition, it is possible to confirm which material is on the positive side by bringing the materials into light contact with each other and examining the polarity with a surface potentiometer.

  In the present invention, the silicon resin and the silicon rubber that are suitably used as a material having a positive chargeability in relation to the charge train than polyurethane are not limited as long as they contain silicon atoms in the main chain skeleton of the molecule. For example, an organopolysiloxane, an organopolymetallosiloxane, an organopolysiloxane having an alkyl group such as a methyl group, an ethyl group, a propyl group, or an aryl group such as a phenyl group, a phenol group, a styryl group, or a benzyl group in the side chain. Examples include polysilazane, organopolysilmethylene, and organopolysilphenylene. These compounds have side chains or molecular ends, for example, amino groups, epoxy groups, mercapto groups, carboxyl groups, hydroxyl groups, alkoxysilyl groups, carbinol groups, alkoxy groups, alkyl groups, aralkyl groups, polyethers, etc. It may be modified, or may be halogenated and modified such as fluorinated or chlorinated. Furthermore, it may be a block copolymer or graft copolymer composed of a chain containing a silicon atom in the main chain skeleton of the molecule and a chain not containing a silicon atom in the main chain skeleton of the molecule. Among these, a resin or rubber having dimethylpolysiloxane or modified dimethylpolysiloxane as a main skeleton is preferable. Further, in addition to a straight-chain structure, the molecule may be cyclic or network-like, that is, partially or completely cross-linked.

In the present invention, the polyamide resin that is preferably used as a material having a positive chargeability in relation to the charge train than polyurethane is not limited in composition as long as it has an amide bond in the molecular skeleton. -Lactams such as propiolactam, γ-butyrolactam, γ-valerolactam, δ-valerolactam, ε-caprolactam, heptactam, lauryllactam, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, Azelaic acid, sebacic acid, 1,10-decanedicarboxylic acid, 1,1
Aliphatic dicarboxylic acids such as 2-dodecane dicarboxylic acid, 1,20-eicosane dicarboxylic acid, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, and alicyclic dicarboxylic acids, ethylenediamine 1,3-trimethylenediamine, 1,4-tetramethylenediamine, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,8-octamethylenediamine, 1,10-decamethylenediamine, , 12-dodecanediamine and the like, alicyclic diamines such as the compound of the general formula (I) described later, and cyclic secondary diamines such as piperazine, and the like. Copolymers such as binary, ternary and quaternary may also be used. The raw material may be a derivative capable of forming an amide bond at the stage of the polymerization raw material.

  In the image forming method of the present invention, it is preferable that the polyamide resin constituting the outermost layer of at least one of the layer thickness regulating member and the developing roller has a diamine compound represented by the general formula (I) as a component. By having the diamine compound represented by the general formula (I) as a component, the charge imparting property to the negatively charged developer in a high temperature and high humidity environment is further suitable. As an action mechanism that exhibits such an effect, the adsorption of water molecules to the amide bond is inhibited by the steric hindrance resulting from the hydrophobicity or bulkiness of the cycloalkylene group in the diamine compound represented by the general formula (I). This is thought to be because the decrease in electrical resistance is suppressed particularly in a high-temperature and high-humidity environment.

(In the formula, A and B each independently represent a cycloalkylene ring which may have a substituent, and R represents an alkylene which may have a direct bond or a substituent.)
The cycloalkylene rings A and B are not limited in their configuration as long as they are aliphatic rings, and are independently, for example, cyclopentylene ring, cyclohexylene ring, cycloheptylene ring, cyclooctylene ring, cyclononylene ring, cyclodecylene ring, Examples thereof include saturated aliphatic rings such as cyclododecylene ring. Further, it may be a polycyclic aliphatic ring such as a norbornenylene ring, a norpinenylene ring, a spirobicyclohexylene ring, a perhydronaphthalene ring, and a cyclobutenylene ring, a cyclohexenylene ring, a cyclohexadienylene ring, a cyclooctenylene ring. It may be an aliphatic ring containing an unsaturated bond such as a ring, a cyclooctadienylene ring or a cyclodecenylene ring. Among these, a cyclopentylene ring, a cyclohexylene ring, and a cyclooctylene ring are preferable, and a cyclohexylene ring is particularly preferable. Further, when the cycloalkylene ring has a structural isomer, any of them may be used.

  There is no limitation on the bonding position of the amino group bonded to the cycloalkylene rings A and B. In the case of the cyclohexylene ring particularly preferred as described above, the amino group bonding position is independently the ortho-position, ie, 1,2-position, the meta-position, ie, 1,3-position, the para-position, ie, 1,4- Any of the positions may be present, but at least one amino group of A and B is preferably in the para position, and both amino groups of A and B are particularly preferably in the para position. The amino group usually forms a polyamide resin by forming an amide bond by reacting with a carboxylic acid group or a derivative thereof.

  R represents a direct bond or alkylene which may have a substituent. Carbon number which comprises alkylene is 1-12 normally, Preferably it is 1-6, More preferably, it is 1-3, Most preferably, it is a methylene. Although the substituent in alkylene which may have a substituent is not limited, the number of carbon atoms is preferably 1-15, more preferably 1-6. By having a substituent in the alkylene, the hydrophobicity of the compound of the general formula (I) is improved, and the effect of suppressing deterioration in image quality under high temperature and high humidity may be improved, but the carbon number of the substituent exceeds the above range. In this case, since the weight ratio of the amide bond portion is relatively lowered, the effect of maintaining the chargeability of the developer may be lowered. Specific examples of the substituent in the alkylene which may have a substituent are preferably an alkyl group, an alkoxy group, and an aryl group. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, and an isopropoxy group. Examples of the aryl group include a phenyl group, a toluyl group, and a naphthyl group. Is preferred. Further, the alkylene and the substituent may be one in which one or more hydrogens are substituted with a halogen element. Among these, R is particularly preferably unsubstituted or methylene in which hydrogen is substituted with 1 or 2 methyl groups.

Moreover, the carbon number which comprises R is 0-12 normally, Preferably it is 0-6, More preferably, it is 0-3, Most preferably, it is 0 or 1.
The substituents in the cycloalkylene rings A and B, which may have a substituent each independently, are not limited, and examples thereof include those capable of substituting an alkylene hydrogen in R, among which the cycloalkylene ring A B is preferably an unsubstituted cycloalkylene ring, or at least one of the cycloalkylene rings A and B is substituted with one or more methyl groups. When substituted with a methyl group, the case where the meta position is substituted with a methyl group is particularly preferred.

  The content of the diamine compound represented by the general formula (I) in the polyamide resin is usually 1 mol% or more, preferably 5 mol% or more, more preferably 10 mol% or more, particularly preferably in all monomer units constituting the polyamide resin. Is 20 mol% or more, usually 50 mol% or less, preferably 40 mol% or less. Here, the total monomer unit means that the dicarboxylic acids and diamines are calculated as independent monomers. When the content of the diamine compound represented by the general formula (I) is less than the above range, the charge imparting property to the negatively charged developer in a high temperature and high humidity environment may be deteriorated. In some cases, it is difficult to form a polyamide resin layer by solution application. The configuration of the polyamide resin can be confirmed by, for example, nuclear magnetic resonance absorption spectrum analysis (NMR).

  In the image forming method of the present invention, when the polyamide resin used in the outermost layer of at least one of the layer thickness regulating member or the developing roller is a multi-component copolymer composed of the above components, it is particularly a high temperature and high humidity environment. The performance such as the charge imparting property below may be improved. Among them, a copolymerized polyamide resin composed of an aliphatic compound other than the diamine compound represented by the general formula (I) is suitable, and in particular, the diamine compound represented by the general formula (I) and lactams, A multi-component copolymerized polyamide resin composed of aliphatic dicarboxylic acids and aliphatic diamines is preferred.

Furthermore, the polyamide resin in the present invention may contain a bifunctional or higher polyisocyanate component, polyol component, polyalkylene ether polyol component, etc., within a range not impairing the effects of the present invention. It may contain a urea bond, an ester bond, an ether bond, or the like.
Although the number average molecular weight of the polyamide resin in this invention is not limited, 5000-50,000 are preferable, More preferably, it is 10,000-30,000. When the number average molecular weight of the polyamide resin is less than the above range or exceeds the above range, a uniform thin layer may not be formed when the polyamide resin thin layer is formed on the developing roller surface by solution coating. Here, as the number average molecular weight of the polyamide resin, a polystyrene conversion value obtained by gel permeation chromatography is used.

  The production method of the polyamide resin used in the present invention is not particularly limited, and a known method for producing a polyamide resin is appropriately applied, and a known polymerization catalyst is used or a non-catalyzed melt polymerization method, a solution polymerization method, an interfacial polymerization method. Etc. are used. In the polymerization, a monobasic acid such as acetic acid or benzoic acid, or a monoacid base such as hexylamine or aniline may be added as a molecular weight modifier. Furthermore, a polyfunctional compound having a trifunctional or higher functional group may be included as long as the effects of the present invention are not impaired. It is also possible to add a heat stabilizer represented by sodium phosphite, sodium hypophosphite, phosphorous acid, hypophosphorous acid and hindered phenol, and other polymerization additives.

The material other than the shape and the outermost layer of the layer thickness regulating member in the present invention is not limited and may be made of metal such as stainless steel, resin, cross-linked elastomer, thermoplastic elastomer, etc. A resin layer may be formed on the surface of the support.
The material other than the shape and the outermost layer of the developing roller in the present invention is not limited, but is usually a substantially cylindrical or circular tube shape including a hollow body, and the diameter is usually 10 to 40 mm, preferably 15 to 30 mm. is there. Among these, a structure in which the outer periphery of the metal shaft is covered with an elastic body or resin is preferable in terms of rigidity and durability of the developing roller. By forming an elastic layer on the outer periphery of the metal shaft, mechanical damage to the photoconductor can be suppressed, particularly in an image forming method in which development is performed in contact with the photoconductor using a non-magnetic one-component method. There are cases where it is possible.

Although the material of the metal shaft in the developing roller is not limited, for example, metal materials such as aluminum, stainless steel, copper and nickel are used, and stainless steel is particularly preferable. The metal shaft may be made of a plurality of metals, and may be of a different material or shape only in the rotating shaft portion.
The material of the elastic body covering the outer periphery of the metal shaft is not limited. For example, polyurethane resin, silicone resin, styrene elastomer, olefin elastomer, urethane rubber, silicone rubber, butadiene rubber, chloroprene rubber, neoprene rubber, A resin such as isoprene rubber, nitrile-butadiene rubber, natural rubber, a crosslinked elastomer, a thermoplastic elastomer, or the like is used, and a plurality of these may be used in combination. Further, the material constituting the elastic layer can contain a conductive agent such as metal powder, carbon black, and graphite, and a filler such as silica and alumina.

In the image forming method of the present invention, when the outermost layer of the developing roller is made of a polyamide resin, it is preferably in close contact with the inner layer in contact therewith. Therefore, the elastic body has a high affinity with the polyamide resin. More selected. If the affinity is low, it may be necessary to improve adhesion by surface modification or use of an adhesive.
The elastic layer may have a laminated structure. In the case of a laminated structure, it is desirable that the outer layer has a lower elastic modulus than the center layer. Furthermore, the elastic body may be a foam or a porous body. The thickness of the elastic layer is not limited, but is usually 1 to 18 mm, preferably 2 to 15 mm, and is included in the diameter of the developing roller.

The method for forming these elastic layers on the outer periphery of the metal shaft is not limited. A sheet-like elastic body obtained by inserting an injection-molded material into a metal shaft, a method by insert injection molding, extrusion molding or the like is used as a metal shaft. Method of winding, fusing or welding as required, method of fitting a cylindrically shaped extrusion into a metal shaft, method of injection molding or press molding, dissolving the material forming the elastic layer in a solvent etc. The method of apply | coating to a metal shaft and drying is mentioned.

  In the present invention, the method for forming the polyamide resin in the outermost layer of the layer thickness regulating member or the developing roller is not limited as long as the surface uniformity of the layer thickness regulating member or the developing roller can be ensured. The method in which the solution is dissolved, and the solution is applied and dried is the easiest and preferred. Examples of the solvent used in this case include alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone and methyl ethyl ketone, aromatic hydrocarbons such as benzene and toluene, and esters such as methyl acetate and ethyl acetate. In addition, halogenated hydrocarbons such as methylene chloride, dichloroethane, and trichloroethylene, water, and the like can be used alone or in combination, but alcohols are preferably used from the viewpoint of solution stability. Examples of the method for applying the solution include a dipping method, a spray method, a nozzle method, a roll coating method, a die coating method, and a brush coating. Examples of drying after application include standing drying at room temperature, drying by heating, and drying under reduced pressure. It is done.

Further, as a method other than coating, for example, a sheet made of polyamide resin or a cylindrical molded body is wound or fused on the outermost layer of the layer thickness regulating member or the developing roller, or this is used as a heat shrinkable tube. For example, a method of shrinking and adhering to the layer thickness regulating member or the developing roller can be used.
In the present invention, when the polyamide resin is formed on the outermost layer of the layer thickness regulating member or the developing roller by solution coating, the thickness of the polyamide resin layer is usually 0.5 μm or more, preferably 3 μm or more, and usually 50 μm or less. The thickness is preferably 30 μm or less. When the thickness of the polyamide layer is less than the above range, the ability to impart a negative charge to the developer tends to be small, and when it exceeds the above range, the thin layer may not be uniform, and the non-uniformity thereof. May appear as uneven density in a solid image or a halftone image.

  When the polyamide resin is used for the outermost layer of the developing roller, the thickness of the polyamide layer is preferably uniform, but the ratio of the thinnest part to the thickest part in the part used for developing the developer is usually It is desirable that the ratio is 1: 1 to 1: 2, preferably 1: 1 to 1: 1.5, more preferably 1: 1 to 1: 1.2. The thickness of the polyamide resin layer can be adjusted by the type of solvent, the solution concentration, the coating method, and the like, and can also be adjusted by the pulling speed when using the dipping method. Even when the outermost layer of the polyamide resin is formed by a method other than solution coating, the same thickness and thickness ratio as described above are preferable.

  When a polyamide resin is used as the outermost layer of the layer thickness regulating member or the developing roller of the present invention, it is usually formed only of the polyamide resin, but may be mixed with other various materials depending on the chargeability of the developer or image forming conditions. May be used. Other materials that can be used by mixing with the above polyamide resin are not limited, but include, for example, metal fine particles such as aluminum, copper and silver, conductive agents such as carbon black and graphite, 6 nylon, 4,6-nylon, Polyamide resins other than the above polyamide resins such as 6,6-nylon, 6,10-nylon, 11 nylon, 12 nylon, etc., polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polycarbonate resins, polyarylate resins, silicone resins, melamine The charge imparting property of the developing roller can be adjusted by adding a resin such as a resin, an acrylic resin, or a phenol resin. Furthermore, the surface shape of the outermost layer of the developing roller is adjusted by adding fine particles of silica, alumina, titania or the like, or fine particles of silicone resin, melamine resin, acrylic resin, phenol resin or the like on the developing roller in the developing device. The toner adhesion amount can be adjusted. Even when these other materials are included, the polyamide resin is desirably contained in an amount of usually 50% by weight or more, preferably 75% by weight or more, more preferably 90% by weight or more of the outermost layer.

Each of the layer thickness regulating member and the developing roller of the present invention desirably has a smooth surface, and the surface roughness Ra according to JIS B0601 is preferably 0.5 μm or less, more preferably 0.005 to 0.3 μm. It is desirable to be. When Ra is within the above range, it is preferable because there is no unevenness in image density and the photoconductor is not damaged.
As described above, the toner for developing an electrostatic charge image of the present invention has excellent low-temperature fixability and offset resistance, and thus is excellent for high-speed printing. In particular, this effect is prominent in the region where the printing speed is 100 mm / s or more, further 150 mm / s or more, particularly 200 mm / s or more. In addition, the image forming method of the present invention does not drop out or leak from the developing device such as a developing roller even during long-time development processing, can suppress contamination in the image forming device, and has high image quality without image density unevenness. It is an excellent thing that can be obtained.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
<Externally added fine particles>
Silica 1: Hexamethyldisilazane treatment,
Average primary particle size is about 30 nm, density is 2.4 g / cm ³ .
Silica 2: treated with dimethylpolysiloxane,
Average primary particle size is about 7 nm, density is 2.4 g / cm ³ .
Titania: Alkyl silane treatment, average primary particle size of about 15 nm, density 4.2 g / cm ³ .
Polymethyl methacrylate resin: Average primary particle size of about 150 nm, density 1.2 g / cm ³ .
Calcium phosphate: Average primary particle size of about 500 nm, density 3.3 g / cm ³ .

<Example 1>
Cyan base toner (average particle size 7.5 μm, circularity 0. 0), which is made by styrene-acrylic acid-n-butyl acrylate copolymer (peak molecular weight 30000), produced by emulsion polymerization aggregation method. 96) Toner 1 was obtained by mixing 1000 parts by weight, 20 parts by weight of silica 1 as externally added fine particles, and 5 parts by weight of silica 2 with a Henschel mixer manufactured by Mitsui Mining Co., Ltd. The charge amount of the toner 1 was −62 μC / g, and the coverage according to the formula (A) was 131%. Table 1 shows the results of measuring the non-offset temperature range by using the toner 1 as a developer by the following method.

[Measurement of non-offset temperature range]
Undecided by remodeling a commercially available full-color laser printer using a toner 1 as a developer (a photoconductor is an organic photoconductor, a development system in which the photoconductor and a developing roller are in contact with each other, and an intermediate transfer system). Printing was performed on the paper surface in a worn state. For printing, a rectangular solid image having an area of 100 cm ² (5 cm × 20 cm) is printed near the upper end of A4 size plain paper (FC Dream manufactured by Kishu Paper Co., Ltd .: weight of about 80 g / m ² ), and toner adheres to each unfixed image. The amount was 1.5 ± 0.03 mg / cm ² .

A fixing machine of Fuji Xerox Co., Ltd. full color laser printer DocuPrint C3530, modified so that the driving speed and fixing temperature can be changed, is used as an evaluation fixing machine, and the fixing speed is 100 mm / s (nip time 90 ms), 200 mm / s ( The nip time was 45 ms).
The unfixed image was inserted with the fixing machine reaching a predetermined speed and temperature. Fixing was performed in increments of 5 ° C. in the range of 100 to 200 ° C., and a lower limit temperature at which cold offset did not occur and an upper limit temperature at which hot offset or paper winding did not occur were confirmed.

<Example 2>
Toner 1 except that silica 1 is 5 parts by weight and silica 2 is 20 parts by weight as externally added fine particles.
In the same manner, Toner 2 was obtained. The charge amount of the toner 2 was −65 μC / g, and the coverage according to the formula (A) was 287%. Table 1 shows the results of measuring the non-offset temperature range in the same manner as in Example 1 using toner 2 as the developer.

<Example 3>
Toner 3 was obtained in the same manner as toner 1 except that 5 parts by weight of silica 1, 20 parts by weight of silica 2, 2 parts by weight of titania, and 2 parts by weight of calcium phosphate were used as externally added fine particles. The charge amount of the toner 3 was −59 μC / g, and the coverage according to the formula (A) was 294%. Table 1 shows the results of measuring the non-offset temperature range in the same manner as in Example 1 using toner 3 as the developer.

<Comparative Example 1>
As external toner, 5 parts by weight of silica 1, 20 parts by weight of silica 2, 15 parts by weight of polymethyl methacrylate resin particles, 2 parts by weight of titania, and 2 parts by weight of calcium phosphate were used in the same manner as toner 1. Toner 4 was obtained. The charge amount of the toner 4 was −43 μC / g, and the coverage according to the formula (A) was 313%. Table 1 shows the results of measuring the non-offset temperature range in the same manner as in Example 1 using toner 4 as the developer.

<Comparative example 2>
Toner 5 was obtained in the same manner as toner 1 except that 5 parts by weight of silica 1, 20 parts by weight of silica 2 and 15 parts by weight of polymethyl methacrylate resin particles were used as externally added fine particles. The charge amount of the toner 5 was −42 μC / g, and the coverage according to the formula (A) was 305%. Table 1 shows the results of measuring the non-offset temperature range in the same manner as in Example 1 using toner 5 as the developer.

  From Table 1, the lower limit of the non-offset temperature is lower in Examples 1 to 3 than in Comparative Examples 1 and 2 at any of the fixing speeds of 100 mm / s and 200 mm / s, and is good even at lower temperatures. It has been confirmed that it can be fixed on.

<Preparation of coating agent>
Coating agent A
127 parts by weight of ε-caprolactam, 121 parts by weight of bis (4-amino-3-methylcyclohexyl) methane, 138 parts by weight of 1,12-dodecanedicarboxylic acid, 13 parts by weight of 80% aqueous solution of hexamethylenediamine, 1,20-eicosanedicarboxylic 34 parts by weight of acid was charged into an autoclave equipped with a stirrer, and after sufficient nitrogen substitution, the temperature was raised. Stirring was started when the internal temperature reached 100 ° C., and the temperature was increased by heating until the internal pressure reached 13 kg / cm ² . After reaching 13 kg / cm ^2, system pressure is to distill water so as to be 13 kg / cm ^2. Next, the valve of the autoclave was closed, and after reacting for 2 hours, the valve was opened and returned to normal pressure. Then, after making it react at 290 degreeC for further 2 hours, the produced | generated molten polymer was extracted and it wash | cleaned 5 times with about 10 weight times boiling water. This was dried at 120 ° C. under reduced pressure for 3 days to obtain polyamide resin A. ^{When the} copolymer composition was determined by ¹³ C-NMR, it was a composition of the following formula and the number average molecular weight was 20,000.

Polyamide resin A was dissolved in a mixed solvent (methanol / n-propanol / toluene = 50/20/30 (weight ratio)) and adjusted to a solid content concentration of 10% to prepare coating agent A. The viscosity of the coating agent A was 0.040 Pa · s at 20 ° C.
Coating agent B
The amount of raw materials charged was 164 parts by weight of ε-caprolactam, 64 parts by weight of bis (4-amino-3-methylcyclohexyl) methane, 73 parts by weight of 1,12-dodecanedicarboxylic acid, 13 parts by weight of an 80% aqueous solution of hexamethylenediamine, A polyamide resin B was obtained by the same method as the polyamide resin A except that 34 parts by weight of 1,20-eicosane dicarboxylic acid was used. ^{When the} copolymer composition was determined by ¹³ C-NMR, it was a composition of the following formula and the number average molecular weight was 12,000.

  Polyamide resin B was dissolved in a mixed solvent (methanol / n-propanol / toluene = 70/10/20 (weight ratio)) and adjusted to a solid content concentration of 10% to prepare coating agent B. The viscosity of the coating agent B was 0.014 Pa · s at 20 ° C.

Example 4
A toner 6 was obtained in the same manner as the toner 1 except that 5 parts by weight of silica 1, 20 parts by weight of silica 2, and 2 parts by weight of titania were used as externally added fine particles. The charge amount of the obtained toner was −40 μC / g, and the coverage according to the formula (A) was 294%.
A polyurethane-based elastic body is formed with a thickness of 6 mm on the outer periphery of a stainless steel metal shaft, and an outermost layer is a polyurethane-based resin (infrared absorption spectrum, proton nuclear magnetic resonance spectrum, GC / MS of alkali methylation reaction pyrolysis, It was a polyether polyurethane composed of toluene diisocyanate / diphenylmethane diisocyanate / polypropylene glycol / glycerin / trimethylolpropane by analysis of the MS spectrum of the pyrogram detection component, and contained a component insoluble in dimethylformamide and dimethyl sulfoxide. .) A commercially available non-magnetic one-component full color laser printer [P1] developing roller (roller diameter 20 mm) coated with a thin layer is used as a base, and the base is immersed in coating agent A at room temperature, and the pulling speed is increased. 150 Pulling in m / min, to form a thin layer of polyamide A in the outermost layer of the developing roller by subsequent drying at 100 ° C. 30 min. When the obtained developing roller was lightly brought into contact with the roller before coating and the probe of the surface potential meter was brought close to it, the developing roller surface coated with the polyamide layer showed positive polarity, and the material constituting the developing roller surface was It was confirmed that it was on the positive side of polyurethane in relation to the charge train. The polyamide A layer had a thickness of 20 μm and a surface roughness Ra of 0.12 μm.
Table 1 shows the evaluation results of the fogging property of the obtained developing roller using toner 6 as a developer by the following method. The thickness of the polyamide layer and the surface roughness Ra of the developing roller were measured by the following method.

[Surface roughness Ra of developing roller]
The surface roughness shape measuring device Surfcom 130A (manufactured by Tokyo Seimitsu Co., Ltd.) was used for measurement according to JIS B601. For each roller, two portions (a total of six locations) of about 1.5 cm inside and the center portion from both ends of the portion where the polyamide layer was formed were measured, and the average value was obtained.
[Thickness of polyamide layer of developing roller]
A part of the polyamide layer of the developing roller was removed by dissolving with ethanol. At this time, the thin polyurethane layer which was the outermost layer before application of the polyamide resin did not dissolve. Using a surface roughness profile measuring device Surfcom 130A (manufactured by Tokyo Seimitsu Co., Ltd.), the surface roughness Ra is included so as to include a portion where the polyamide layer is interrupted (the boundary between the portion where the polyamide layer is dissolved and the portion where the polyamide layer is not dissolved). Scanning was performed under the same conditions as in the measurement, and the thickness of the polyamide layer was measured from the shape of the obtained cross-sectional curve (the size of the step). For each roller, two portions (a total of six locations) of about 1.5 cm inside and the center portion from both ends of the portion where the polyamide layer was formed were measured, and the average value was obtained.

[Fog evaluation by printing]
A developing roller having a polyamide resin coated on the surface and dried is a commercially available non-magnetic one-component type full-color laser printer [P1] (the photosensitive member is an organic photosensitive member, and a developing method in which the photosensitive member and the developing roller are in contact with each other). Yes, a tandem printer that does not use an intermediate transfer member.) The cartridge type developing device (the layer thickness regulating member is made of stainless steel and presses the developing roller), and 30 g of toner 6 is filled in the developing device. Above, a white background pattern was output on white plain paper. The fog printed on the white background image was visually determined according to the following criteria.

When performing printing, the laser printer incorporating the developing roller was left to stand for 12 hours in two environments of 23 ° C./50% relative humidity and 28 ° C./80% relative humidity, and then evaluated.
A: Very little fog (a level at which the stain on the printed image can hardly be visually confirmed)
○: Fog is small (slight dirt is confirmed by staring, but there is no practical problem)
X: A lot of fog (a level at which dirt can be judged at a glance)

(Example 5)
A thin layer of polyamide B was formed on the outermost layer of the developing roller in the same manner as in Example 4 except that the coating agent B was used as the coating agent and the pulling rate was 200 mm / min. When the charging characteristics on the surface of the obtained developing roller were confirmed in the same manner as in Example 4, it was confirmed that the charging roller was on the positive side with respect to the polyurethane in relation to the charge train.
The thickness of the polyamide B layer measured by the same method as in Example 4 was 20 μm, and the surface roughness Ra was 0.
. 18 μm. Table 2 shows the results of evaluation of fogging using the obtained developing roller in the same manner as in Example 4.

(Comparative Example 3)
Table 2 shows the results of evaluation of fogging in the same manner as in Example 4 except that the developing roller (surface is polyurethane resin) was used as it was without coating with polyamide.

(Example 6)
Polyurethane (methylenediphenyl diisocyanate (MDI) / polycaprolactone (number average molecular weight 2000) / 1,4-butanediol = 3/2/1 (mol ratio)) on one side of a stainless steel plate having a thickness of 0.1 mm and crosslinked Is a commercially available non-magnetic one-component full-color laser printer [P2] (the photosensitive member is an organic photosensitive member, and a developing method in which the photosensitive member and the developing roller are in contact with each other). Yes, an intermediate transfer type printer) layer thickness regulating member (248 mm × 16 mm × 1.1 mm, polyurethane is formed at the end of the side surface of the metal plate so as to face the developing roll). The substrate is immersed in the coating agent A at room temperature and then lifted, and then dried at 100 ° C. for 30 minutes, so that the outermost layer of the layer thickness regulating member is coated with poly. A thin layer of amide A was formed. The surface of the layer thickness regulating member coated with the polyamide layer is lightly brought into contact with the surface where the developer comes into contact with the layer thickness regulating member before coating the obtained layer thickness regulating member, and the surface potential meter probe is brought close to the surface. The positive polarity was shown, and it was confirmed that the material constituting the surface of the layer thickness regulating member was on the positive side with respect to the polyurethane in relation to the charge train. The polyamide A layer had a thickness of 10 μm and a surface roughness Ra of 0.10 μm.

Table 3 shows the results of the toner leakage evaluation using the toner 6 as the developer and the obtained layer thickness regulating member by the following method. The thickness of the polyamide layer and the surface roughness Ra of the layer thickness regulating member were measured by the following method.
[Surface roughness Ra of layer thickness regulating member]
The surface roughness shape measuring device Surfcom 130A (manufactured by Tokyo Seimitsu Co., Ltd.) was used for measurement according to JIS B601. About a surface of the layer thickness regulating member facing the developing roller (a surface on which the polyamide layer is formed on the surface of the elastic body), about 1.
The 5 cm inner part and the central part were measured one by one (3 places in total), and the average value was obtained.

[Thickness of polyamide layer of layer thickness regulating member]
A part of the polyamide layer of the layer thickness regulating member was removed by dissolving in ethanol. At this time, the polyurethane which was the outermost layer before application of the polyamide resin did not dissolve. Using a surface roughness profile measuring device Surfcom 130A (manufactured by Tokyo Seimitsu Co., Ltd.), the surface roughness Ra is included so as to include a portion where the polyamide layer is interrupted (the boundary between the portion where the polyamide layer is dissolved and the portion where the polyamide layer is not dissolved). Scanning was performed under the same conditions as in the measurement, and the thickness of the polyamide layer was measured from the shape of the obtained cross-sectional curve (the size of the step). For the surface of the layer thickness regulating member that faces the developing roller (the surface on which the polyamide layer is formed on the surface of the elastic body), about 1.5 cm inside part and the center part from both ends of the part where the polyamide layer is formed Each one was measured (three places in total), and the average value was obtained.

[Toner leakage evaluation]
A layer-thickness regulating member having a polyamide resin coated and dried on the surface is a cartridge-type developing device of the above-mentioned commercially available non-magnetic one-component full-color laser printer [P2] (the developing roller does not have a soft elastic layer. The regulating member is pressed into the developing roller.) 65 g of toner is filled in the developing device, and then intermittent driving is performed (2.5 seconds driving / 2.5 seconds stationary without printing or toner consumption). ) Was carried out. The developing roller peripheral speed during driving was set to 301 mm / s. This speed corresponds to twice the developing roller peripheral speed (200 mm / s) at the normal printing speed (100 mm / s) of the printer. At that time, the time when the toner leakage occurred from the developing device was observed and evaluated according to the following criteria.

In the evaluation, a cartridge type developing device incorporating a developing amount regulating member and filled with toner was left for 12 hours in an environment of two levels of 23 ° C./50% relative humidity or 28 ° C./80% relative humidity. Later, each environment was evaluated.
○: No toner leakage even after 2 hours. (No hindrance to use)
Δ: Toner leakage occurred between 10 minutes and 2 hours.

(Image contamination due to contamination inside the device may occur)
X: Toner leakage occurred in less than 10 minutes.
(The leaked toner is extremely contaminated in the device and cannot be used.)

(Example 7)
A thin layer of polyamide B was formed on the outermost layer of the layer thickness regulating member in the same manner as in Example 6 except that the coating agent B was used as the coating agent. When the charging characteristics on the surface of the obtained layer thickness regulating member were confirmed in the same manner as in Example 3, it was confirmed that it was on the plus side of polyurethane in relation to the charge train.

The thickness of the polyamide B layer measured by the same method as in Example 6 was 10 μm, and the surface roughness Ra was 0.
. It was 20 μm. Table 3 shows the results of performing the toner leakage evaluation using the layer thickness regulating member in the same manner as in Example 6.
(Comparative Example 4)
Table 3 shows the results of the toner leakage evaluation in the same manner as in Example 6 except that the layer thickness regulating member (the surface is polyurethane) was used as it was without coating with polyamide.

Claims (8)

An electrostatic image developing toner used for non-magnetic one-component development, which is obtained by an emulsion polymerization aggregation method, and has a coverage of externally added fine particles calculated by the following formula (A) of 300. % Or less of the toner for developing electrostatic images.

Dt: Average particle diameter of toner base particles (μm)
ρt: True density of toner base particles (g / cm ³ )
Dn: average particle diameter of externally added fine particles n (μm)
ρn: true density of externally added fine particles n (g / cm ³ )
Wn: number of added external fine particles n (parts by weight based on 100 parts by weight of toner base particles)
a: Number of types of externally added fine particles.   2. The toner for developing an electrostatic charge image according to claim 1, comprising silica treated with a silane coupling agent or silicone oil as external fine particles.   The electrostatic charge image developing toner according to claim 1, wherein the charge amount is −90 to −10 μC / g.   A non-magnetic one-component image forming method using the electrostatic image developing toner according to any one of claims 1 to 3 as a developer, comprising: a layer thickness regulating member and a developing roller constituting the image forming apparatus An image forming method, wherein at least one of the outermost layers is made of a material having a charging property on the plus side in relation to a charged column as compared with polyurethane.   The image forming method according to claim 4, wherein the material on the plus side in relation to the charged column than polyurethane contains a polyamide resin. 6. The image forming method according to claim 4, wherein the polyamide resin has a diamine compound represented by the following general formula (I) as a component.

(In the formula, A and B each independently represent a cycloalkylene ring which may have a substituent, and R represents an alkylene which may have a direct bond or a substituent.) The image forming method according to claim 6, wherein the content of the diamine compound represented by the general formula (I) is 1 to 50 mol% in all monomer units constituting the polyamide resin.   The image forming method according to claim 4, wherein the fixing is performed at a speed of 100 mm / sec or more.