JP4069716B2 - Carrier for electrostatic image developer, electrostatic image developer - Google Patents

Description

【００８７】
【表２】

【００８８】
【表３】

【００８９】
なお、表３中、「画質」の欄の「＊１」「＊２」「＊３」「＊４」は以下を意味する。
＊１：Ｘ−Ｒｉｔｅ９３８で測定した画像濃度が低濃度（１．０以下である）
＊２：画像白抜け／キャリア飛散の発生
＊３：感光体残りによるスジの発生
＊４エッジ効果／疑似輪郭等の発生
【００９０】
また、表３中、「転写性」の欄の「Ｇ０」〜「Ｇ５」は、感光体転写残りトナーを観察することにより転写性をグレード評価したもので、Ｇ０が最も優れた転写性を意味し、数字の増加に伴い転写性が悪くなり、Ｇ５が最も悪い転写性を意味する。なお、Ｇ０〜Ｇ２が、実用上問題の無いレベルとした。
【００９１】
【発明の効果】
以上に説明したように、本発明によれば、磁性体からなる芯材に少なくとも表面を樹脂で被覆したキャリアにおいて、前記キャリアの被覆樹脂中に樹脂粒子又は導電性粒子が少なくとも１種類以上が分散含有されてなり、前記樹脂粒子又は該導電性粒子の少なくとも１種類以上が脂肪酸金属塩で表面を被覆してあることを特徴とする静電荷像現像剤用キャリア及び該キャリアを使用した現像剤は、帯電性、転写性、クリーニング性が優れ、安定した画質維持性を実現できる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrostatic charge image developing carrier and an electrostatic charge image developer used in electrophotography, electrostatic recording method and the like.
[0002]
[Prior art]
An electrophotographic method for visualizing image information through an electrostatic latent image is currently used in various fields (see, for example, Patent Document 1 and Patent Document 2). In the electrophotographic method, generally, an electrostatic latent image is formed on a photoreceptor in a charging / exposure process, and the electrostatic latent image is developed with a developer containing toner in a developing process to form a toner image. In the transfer step, the toner image is transferred onto a transfer material such as paper or sheet. In the fixing step, the toner image is fixed on the transfer material using heat, solvent, pressure, etc. How to get.
[0003]
There are many known developing methods for the developer. As such a developing method, a cascade developing method (refer to Patent Document 3), a magnetic brush method (refer to Patent Document 4), a touchdown method (refer to Patent Document 5), and between a developer carrying member and a photosensitive member. There is a jumping brush developing method for performing development by applying a bias electric field.
[0004]
Among them, a typical method of so-called two-component developer obtained by mixing a carrier and a toner is a magnetic brush method. In this method, magnetic particles such as steel and ferrite are used as a carrier, a developer composed of toner and a magnetic carrier is supported by a magnet, and the developer is formed in a brush shape by the magnetic field of the magnet. Next, when the magnetic brush comes into contact with the electrostatic latent image on the photoreceptor, the toner in the brush is attracted according to the amount of charge of the latent image and developed.
[0005]
The carrier is roughly classified into a coated carrier having a coating on the surface and an uncoated carrier having no coating on the surface, but the coated carrier is superior when considering the lifetime of the developer. Therefore, various coated carriers have been developed and put into practical use. The properties of the coated carrier are required to at least be able to impart appropriate chargeability (charge amount and charge distribution) to the toner and to maintain the appropriate chargeability over a long period of time. Therefore, various coated carriers have been proposed that do not change the chargeability of the toner, are excellent in impact resistance and friction resistance, and are stable against environmental changes such as humidity and temperature.
[0006]
For example, by coating the surface of the carrier core with a copolymer of a nitrogen-containing fluorinated alkyl (meth) acrylate and a vinyl monomer, or a copolymer of a fluorinated alkyl (meth) acrylate and a nitrogen-containing vinyl monomer. There is a method of obtaining a relatively long-life coated carrier (see Patent Documents 6 to 8). Also, there is a method in which a polyamide resin or a melamine resin is coated on the surface of the carrier core material and cured to obtain a coated carrier having a relatively hard coating (see, for example, Patent Documents 9 and 10).
[0007]
However, in the case of these carriers, there is a problem that contamination (impact) on the carrier surface by the toner component cannot be prevented.
In order to prevent the impaction, for example, it is considered to form a film of the carrier using a resin having a small surface energy such as a silicone resin or a fluorine resin (see Patent Documents 11 and 12). However, in such a carrier, although the silicone resin and the fluorine-based resin are relatively abundant in the vicinity of the carrier surface, there are only a few in the thickness direction of the coating layer. When used for a period, the effect of the resin is gradually lost due to wear of the coating, and conversely, the impact is gradually generated. In addition, when performing continuous copying using such a developer, an image with excellent density reproducibility and image quality can be obtained initially, but after tens of thousands of copies, the image density decreases and The tonality and graininess become poor. In other words, image quality deterioration due to contamination (impact) on the carrier surface was inevitable.
[0008]
In addition, a carrier containing or coated with a fatty acid metal salt has been proposed (see Patent Documents 13 to 15). However, when the carrier is simply contained, the carrier surface is not uniformly dispersed and a sufficient impact prevention effect is obtained. I can't. Although the impact can be temporarily suppressed with respect to the coating, the effect is lost due to wear of the coating layer over time.
[0009]
[Patent Document 1]
US Pat. No. 2,297,691
[Patent Document 2]
U.S. Pat. No. 2,357,809
[Patent Document 3]
US Pat. No. 2,618,552
[Patent Document 4]
U.S. Pat. No. 2,874,063
[Patent Document 5]
US Pat. No. 2,895,847
[Patent Document 6]
JP 61-80161 A
[Patent Document 7]
JP 61-80162 A
[Patent Document 8]
JP 61-80163 A
[Patent Document 9]
Japanese Patent Laid-Open No. 1-18150
[Patent Document 10]
Japanese Patent Laid-Open No. 2-79862
[Patent Document 11]
JP-A-60-186844
[Patent Document 12]
JP-A 64-13560
[Patent Document 13]
JP-A-64-86159
[Patent Document 14]
JP-A-1-180563
[Patent Document 15]
JP-A-3-242657
[0010]
[Problems to be solved by the invention]
An object of the present invention is to provide an electrostatic image developing carrier and an electrostatic image developer intended to solve the above-described problems.
[0011]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-described problems of the prior art, the present inventors have invented achieving the above object by using metal oxide-coated resin fine particles and / or conductive particles as a carrier. did. Specifically, the configuration is as follows.
[0012]
    <1> In a carrier in which the surface of a core material made of a magnetic material is coated with a resin, one or more particles selected from resin particles and conductive particles are dispersed and contained in the resin, and the particles are dispersed and contained One kind ofThe particle surface is coated with alkoxysilane or polysiloxane and thenA carrier for an electrostatic charge image developer, the surface of which is coated with a fatty acid metal salt.
[0013]
<2> The carrier for an electrostatic charge image developer according to <1>, wherein the surface of the dispersed particles is coated with a fatty acid metal salt component in a thickness of 0.5 to 50 nm. is there.
[0014]
<3> One type of the surface of the particles contained in the dispersion is coated with an organosilane compound or polysiloxane generated from alkoxysilane, and a fatty acid metal salt is attached to the coating. The carrier for an electrostatic charge image developer according to <1> or <2>.
[0015]
<4> The electrostatic charge image developer carrier according to any one of <1> to <3>, wherein the dispersed particles are resin particles made of a nitrogen-containing resin. .
[0016]
<5> The particle according to any one of <1> to <4>, wherein the dispersed particles are carbon black, metal, metal oxide, and / or a composite thereof. The electrostatic charge image developer carrier.
[0017]
    <6> In an electrostatic charge image developer composed of a carrier and a toner,
  The toner shape factor SF1 (ML²/ A) is in the range of 100 to 140, the carrier has a core material made of a magnetic material, and a resin coating layer that covers the surface of the core material, and the resin particles and the conductive particles in the resin coating One or more kinds of particles selected from the above are dispersed and contained, and one kind of the particles contained and dispersed is:The particle surface is coated with alkoxysilane or polysiloxane, thenAn electrostatic charge image developer which is a carrier having a surface coated with a fatty acid metal salt component.
[0018]
[Embodiments of the Invention]
  The electrostatic charge image developer carrier of the present invention will be described below.
  The carrier for an electrostatic charge image developer of the present invention (hereinafter sometimes abbreviated as “carrier”) is a carrier in which the surface of a core material made of a magnetic material is coated with a resin. Resin particles and conductive particles in the resin One or more kinds of particles selected from the above are dispersed and contained, and one kind of the particles that are dispersed and contained isThe particle surface is coated with alkoxysilane or polysiloxane and thenThe surface is coated with a fatty acid metal salt.
[0019]
In a developer composed of a toner and a carrier, the chargeability of the developer deteriorates (decreases) with long-term use. As a result, there arises a problem that internal contamination and fogging on the transfer material occur. One of the causes is that the carrier surface is contaminated with toner components including additives on the toner surface after long-term use.
[0020]
Although details are not clear, the mechanisms are roughly estimated as shown in the following 1) to 3). 1) The charge imparting ability is reduced when the contaminated carrier portion is switched from the carrier surface component to the contaminated component (impact-dominated type). 2) The carrier coating layer is worn or broken due to the developer agitating stress or collision between carriers in the developer (coating layer degradation type). Further, as another adverse effect caused by wear and destruction, the carrier resistance is lowered by exposing the surface of the core material, and an image quality defect due to carrier scattering resulting from the carrier resistance reduction occurs.
[0021]
With respect to the above problems, the carrier of the present invention can suppress the impact to some extent because the surface of the core material is covered with resin. In addition, it is more effective for suppression of impaction to use the low surface energy material represented by the fluororesin or the silicone resin as a resin coating layer which coat | covers the surface of this core material.
[0022]
In addition, the carrier of the present invention is such that resin particles are always present on the surface of the carrier even when the resin coating layer becomes thin with long-term use by adding resin fine particles having a charge imparting property to the resin coating layer. Therefore, a desired charge amount can be obtained even after long-term use. In addition, by adding conductive particles to the resin coating layer, it will always exhibit a certain level of conductivity even when the resistance increases due to impaction, or conversely, the resistance decreases due to wear of the coating layer. Can be suppressed.
[0023]
However, when the toner is used for a longer period, the toner component starts to impact on the resin particles and conductive particles. Therefore, impaction can be suppressed by surface treatment of resin particles and conductive particles. Examples of the surface treatment agent include known materials such as a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, or a silicone oil treatment. However, these treatment agents are limited in uniformity, throughput, and treatment layer thickness.
[0024]
Thus, as a result of intensive studies by the present inventors, it has been found that coating the surface of resin particles or conductive particles with a fatty acid metal salt is more effective in suppressing impact during long-term use. The thickness of the resin particles and the fatty acid metal salt that covers the surface of the conductive particles is not particularly limited, but is preferably in the range of 0.5 to 50 nm.
[0025]
The resin particles used in the present invention are in the range of 0.5 to 40 parts by weight, more preferably 5 to 20 parts by weight with respect to the amount of the carrier coating resin. If the amount is less than 0.5 parts by weight, there is no charge maintaining effect, and if it exceeds 40 parts by weight, the coating layer becomes brittle and the coating layer breaks down due to long-term use. Moreover, electroconductive particle is 0.5-60 weight part, More preferably, it is 10-40 weight part. If the amount is 0.5 parts by weight or less, conductivity may not be obtained. On the other hand, when the amount is more than 60 parts by weight, the carrier resistance is remarkably lowered, and an image quality defect derived from low resistance may occur.
[0026]
Next, a method for producing resin particles and conductive particles whose surfaces are coated with a fatty acid metal salt according to the present invention will be described.
Resin particles or conductive particles whose surfaces are coated with a fatty acid metal salt according to the present invention are prepared by mixing resin particles or conductive particles with alkoxysilane or polysiloxane, and then coating the particle surfaces of the resin particles or conductive particles with alkoxysilane or polysiloxane. It can be obtained by coating with siloxane and then mixing the fatty acid metal salt with resin particles or conductive particles coated with alkoxysilane or polysiloxane.
[0027]
The coating of resin particles or conductive particles with alkoxysilane or polysiloxane is performed by mechanically mixing and stirring resin particles or conductive particles and alkoxysilane or polysiloxane, or by adding alkoxysilane or polysiloxane to resin particles or conductive particles. Mixing and stirring may be performed mechanically while spraying. Almost all of the added alkoxysilane or polysiloxane is coated on the surface of resin particles or conductive particles. In addition, the coated alkoxysilane may be coated as an organosilane compound generated from an alkoxysilane, a part of which is generated through a coating process. Even in this case, the subsequent adhesion of the fatty acid metal salt is not affected.
[0028]
Mixing and stirring of resin particles or conductive particles and alkoxysilane or polysiloxane, and mixing of the fatty acid metal salt and resin particles or conductive particles coated with an organosilane compound or polysiloxane generated from alkoxysilane on the particle surface As an apparatus for stirring, an apparatus capable of applying a shearing force to the powder layer is preferable. In particular, an apparatus capable of simultaneously performing shearing, spatula and compression, such as a wheel-type kneader, a ball-type kneader. A blade-type kneader or a roll-type kneader can be used.
[0029]
In producing the carrier of the present invention, a wheel type kneader can be used more effectively. Specific examples of the wheel-type kneader include edge runners (synonymous with “mix muller”, “Simpson mill”, “sand mill”), multi-mal, stotz mill, wet pan mill, conner mill, and ring muller. , Preferably an edge runner, multi-mal, Stots mill, wet pan mill, and ring muller, and more preferably an edge runner. Specific examples of the ball kneader include a vibration mill. Specific examples of the blade-type kneader include a Henschel mixer, a planetary mixer, and a nauta mixer. Specific examples of the roll-type kneader include an extruder.
[0030]
The conditions at the time of mixing and stirring are such that the linear load is 19.6 to 1960 N / cm (2 to 200 Kg / cm) so that alkoxysilane or polysiloxane is coated as uniformly as possible on the surface of the resin particles or conductive particles. The treatment conditions are preferably 98 to 1470 N / cm (10 to 150 Kg / cm), more preferably 147 to 980 N / cm (15 to 100 Kg / cm), and the treatment time is 5 to 120 minutes, preferably 10 to 90 minutes. May be adjusted as appropriate. In addition, what is necessary is just to adjust processing conditions suitably in the range of stirring speed 2-2000rpm, Preferably 5-1000rpm, More preferably, it is 10-800rpm.
[0031]
As for the addition amount of alkoxysilane or polysiloxane, 0.15-45 weight part is preferable with respect to 100 weight part of resin particles or electroconductive particle. When the amount is less than 0.15 parts by weight, it is difficult to attach a fatty acid metal salt sufficient to obtain resin particles or conductive particles whose surfaces are uniformly coated with the target fatty acid metal salt. Since the addition amount of 0.15 to 45 parts by weight allows 3 to 30 parts by weight of the fatty acid metal salt to be attached to 100 parts by weight of the resin particles, there is no point in adding more than 45 parts by weight more than necessary. .
[0032]
Next, a solid fatty acid metal salt is added to the resin particles or conductive particles coated with alkoxysilane or polysiloxane, and mixed and stirred to adhere the fatty acid metal salt to the alkoxysilane coating or polysiloxane coating. If necessary, drying or heat treatment may be further performed.
The fatty acid metal salt is preferably added in small portions over time, particularly over about 5 to 60 minutes.
[0033]
The conditions at the time of mixing and stirring are such that the linear load is 19.6 to 1960 N / cm (2 to 200 Kg / cm), preferably 98 to 1470 N / cm (10 to 150 Kg / cm) so that the fatty acid metal salt is uniformly attached. More preferably, the processing conditions may be appropriately adjusted within the range of 147 to 980 N / cm (15 to 100 Kg / cm) and the processing time of 5 to 120 minutes, preferably 10 to 90 minutes. In addition, what is necessary is just to adjust processing conditions suitably in the range of stirring speed 2-2000rpm, Preferably 5-1000rpm, More preferably, it is 10-800rpm.
[0034]
The addition amount of the fatty acid metal salt is 3 to 30 parts by weight with respect to 100 parts by weight of the resin particles or conductive particles. Preferably it is 3-15 weight part. When the addition amount of the fatty acid metal salt is outside the above range, resin particles or conductive particles whose surface is uniformly coated with the target fatty acid metal salt cannot be obtained. Furthermore, it is desirable that the surface of the particle whose surface is coated with the fatty acid metal salt is coated with the fatty acid metal salt with a thickness of 0.5 to 50 nm in order to exert the effect. More preferably, the surface is covered by 95% or more, and further, the entire surface is covered.
[0035]
The heating temperature in the drying or heating step is usually preferably 40 to 150 ° C, more preferably 60 to 120 ° C. The treatment time is preferably 10 minutes to 12 hours, more preferably 30 minutes to 3 hours.
The alkoxysilane used for coating the resin particles is finally coated with an organosilane compound produced from the alkoxysilane through these steps.
[0036]
Examples of the resin particles used in the present invention include thermoplastic resin particles and thermosetting resin particles. Among these, a thermosetting resin is preferable from the viewpoint of relatively easily increasing the hardness, and resin particles made of a nitrogen-containing resin containing N atoms are more preferable from the viewpoint of imparting negative chargeability to the toner. In addition, these resin particles may be used individually by 1 type, and may use 2 or more types together.
The average particle diameter of the resin particles is preferably about 0.1 to 2 μm, and more preferably 0.2 to 1 μm, for example. If the average particle size of the resin particles is less than 0.1 μm, the dispersibility of the resin particles in the coating is very poor. On the other hand, if the average particle size exceeds 2 μm, the resin particles easily fall off from the coating, and the original effect is obtained. It may stop working.
[0037]
The conductive particles used in the present invention include carbon black particles, metal particles such as gold, silver and copper, conductive oxide particles such as titanium oxide and zinc oxide, titanium oxide, zinc oxide, barium sulfate and aluminum borate. And particles having the surface of potassium titanate powder or the like covered with tin oxide, carbon black, metal or the like.
These may be used individually by 1 type and may use 2 or more types together. Among these, carbon black particles are preferable from the viewpoints of production stability, cost, conductivity, and the like. The type of carbon black is not particularly limited, but carbon black having a DBP oil absorption of about 50 to 250 ml / 100 g is preferable because of excellent production stability.
[0038]
As the fatty acid metal salt for coating the resin particles or conductive particles in the present invention, conventionally known fatty acid salts can be used, such as aluminum stearate, calcium stearate, potassium stearate, magnesium stearate, barium stearate, lithium stearate, Zinc stearate, copper stearate, lead stearate, nickel stearate, strontium stearate, cobalt stearate, cadmium stearate, zinc oleate, manganese oleate, iron oleate, cobalt oleate, copper oleate, oleic acid Magnesium, lead oleate, zinc palmitate, cobalt palmitate, copper palmitate, magnesium palmitate, aluminum palmitate, calcium palmitate, zinc linoleate, linole Cobalt, calcium linoleate, zinc ricinoleate, cadmium ricinoleate and caproate and the like.
[0039]
Examples of the carrier core material in the present invention include magnetic metals such as iron, steel, nickel, cobalt, alloys of these with manganese, chromium, rare earth, and magnetic oxides such as ferrite and magnetite. From the viewpoint of core material surface properties and core material resistance, ferrite, particularly alloys with manganese, lithium, strontium, magnesium and the like are preferable, but are not limited thereto. The average particle diameter of the core material is generally 10 to 500 μm, preferably 30 to 100 μm.
[0040]
The carrier of the present invention is formed by coating a resin on the surface of the core material, and the resin is not particularly limited as long as it can be used as a matrix resin, and can be appropriately selected according to the purpose. Polyolefin resins such as polyethylene and polypropylene; polyvinyl resins and polyvinylidene resins such as polystyrene, acrylic resin, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether and polyvinyl ketone; Vinyl chloride-vinyl acetate copolymer; Styrene-acrylic acid copolymer: Straight silicone resin composed of organosiloxane bond or modified product thereof; polytetrafluoroethylene, polyvinyl fluoride, polyvinyl fluoride Fluorine resins such as polyethylene and polychlorotrifluoroethylene; silicone resins: polyesters; polyurethanes; polycarbonates; phenol resins; urea-formaldehyde resins, melamine resins, benzoguanamine resins, urea resins, polyamide resins and other amino resins; epoxy resins, etc. These are known resins per se. These may be used individually by 1 type and may use 2 or more types together.
[0041]
In the present invention, among these resins, it is preferable to use at least a fluororesin and / or a silicone resin. The use of at least a fluorine-based resin and / or a silicone resin as the resin is advantageous in that it has a high effect of preventing carrier contamination (impact) due to toner and external additives.
[0042]
Specifically, the carrier core material is immersed in the film forming liquid, a spray method in which the film forming liquid is sprayed on the surface of the carrier core material, and the carrier core material is floated by flowing air And a kneader coater method in which the solvent is removed by mixing with the film forming solution. Among these, the kneader coater method is preferable in the present invention.
The solvent used in the film-forming liquid is not particularly limited as long as it can dissolve only the resin as a matrix resin, and can be selected from among solvents known per se, for example, And aromatic hydrocarbons such as toluene and xylene, ketones such as acetone and methyl ethyl ketone, and ethers such as tetrahydrofuran and dioxane.
[0043]
When the resin particles are dispersed in the coating, since the resin particles and the particles as the matrix resin are uniformly dispersed in the thickness direction and the tangential direction of the carrier surface, the carrier is used for a long time. Even when the coating is worn, surface formation similar to that at the time of non-use can always be maintained, and good charge imparting ability can be maintained for the toner over a long period of time. Further, when the conductive particles are dispersed in the resin, the conductive particles and the resin as the matrix resin are uniformly dispersed in the thickness direction and the tangential direction of the carrier surface. Even when the coating is worn out for a long period of time, the same surface formation as when not in use can be maintained, and carrier deterioration can be prevented for a long period of time. In addition, when the said resin particle and the said electroconductive particle are disperse | distributed to the said film, the above-mentioned effect can be show | played simultaneously.
The average film thickness of the resin coating layer is usually 0.1 to 10 μm, but in the present invention, it is preferably in the range of 0.5 to 3 μm in order to develop a stable volume resistivity of the carrier over time. .
[0044]
The volume resistivity of the carrier formed as described above corresponds to the upper and lower limits of a normal development contrast potential in order to achieve high image quality.^Three-10^FourIn the range of V / cm, 10⁶-10¹⁴It is preferably Ωcm. The volume resistivity of the carrier is 10⁶If it is less than Ωcm, the reproducibility of fine lines is poor, and toner fogging on the background due to charge injection tends to occur. The volume resistivity of the carrier is 10¹⁴If it is larger than Ωcm, black solid and halftone reproduction will be worse. In addition, the amount of carrier transferred to the photoconductor increases and the photoconductor is easily damaged.
[0045]
The electrostatic image developer of the present invention (hereinafter sometimes abbreviated as “developer”) is effective by using a two-component developer in combination with the carrier of the present invention described above and the specific toner described below. To be effective.
That is, the toner includes at least a binder resin, a colorant, and a release agent, and can have a volume average particle diameter of 2 to 8 μm. In addition, the toner shape factor SF1 (ML²By using a film having a / A) within the range of 100 to 140, a high development, transferability and high quality image can be obtained.
[0046]
The toner used in the present invention is not particularly limited by the production method as long as it satisfies the above shape factor and particle size, and a known method can be used.
[0047]
For example, the toner is produced by kneading, pulverizing, and classifying a binder resin, a colorant, a release agent, and, if necessary, a charge control agent. Method of changing shape by force or thermal energy, emulsion polymerization of polymerizable monomer of binder resin, dispersion of formed dispersion, colorant, release agent, and charge control agent as required Emulsion polymerization agglomeration method to obtain toner particles by mixing and agglomerating and heat fusing the liquid, polymerizable monomer and colorant, release agent, and charge control agent if necessary Suspension polymerization method in which the solution is suspended in an aqueous solvent for polymerization, a binder resin and a colorant, a release agent, and if necessary, a solution such as a charge control agent is suspended in an aqueous solvent for granulation A suspension method or the like can be used. In addition, a manufacturing method may be performed in which the toner obtained by the above method is used as a core, and agglomerated particles are further adhered and heat-fused to give a core-shell structure. In particular, a wet process toner that makes it easy to obtain a spherical toner is preferably used, and toner particles obtained by an emulsion polymerization agglomeration method are preferably used because toner particles having a sharp distribution can be obtained.
[0048]
As the binder resin used, styrenes such as styrene and chlorostyrene, monoolefins such as ethylene, propylene, butylene and isoprene, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl butyrate, Α-methylene aliphatic monocarboxylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Homopolymers and copolymers such as vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone. In particular, typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, and styrene-anhydride maleate. Examples thereof include acid copolymers, polyethylene, and polypropylene. Further examples include polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like.
[0049]
In addition, toner colorants include magnetic powders such as magnetite and ferrite, carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, and malachite green oxa. Rate, lamp black, rose bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 17, C.I. I. Pigment blue 15: 1, C.I. I. Pigment Blue 15: 3 can be exemplified as a representative one.
[0050]
Typical examples of the releasing agent include low molecular weight polyethylene, low molecular weight polypropylene, Fischer-Tropsch wax, montan wax, carnauba wax, rice wax, and candelilla wax.
In addition, a charge control agent may be added to the electrostatic latent image developing toner of the present invention as necessary. Known charge control agents can be used, but azo metal complex compounds, metal complex compounds of salicylic acid, and resin type charge control agents containing polar groups can be used. When the toner is manufactured by a wet manufacturing method, it is preferable to use a material that is difficult to dissolve in water in terms of controlling ionic strength and reducing wastewater contamination. The toner in the present invention may be either a magnetic toner containing a magnetic material or a non-magnetic toner containing no magnetic material.
[0051]
Examples of inorganic oxide fine particles added to the toner include SiO.₂, TiO₂, Al₂O_Three, CuO, ZnO, SnO₂, CeO₂, Fe₂O_Three, MgO, BaO, CaO, K₂O, Na₂O, ZrO₂, CaO · SiO₂, K₂O. (TiO₂) N, Al₂O_Three・ 2SiO₂, CaCO_Three, MgCO_Three, BaSO_Four, MgSO_FourEtc. can be illustrated. Of these, silica fine particles and titania fine particles are particularly preferable. It is desirable that the surface of the oxide fine particles is previously hydrophobized. This hydrophobization treatment is more effective for improving the powder fluidity of the toner, as well as the environmental dependency of charging and the resistance to carrier contamination.
[0052]
The hydrophobizing treatment can be performed by immersing the inorganic oxide in a hydrophobizing agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, and aluminum coupling agents. These may be used individually by 1 type and may use 2 or more types together. Of these, silane coupling agents are preferred.
[0053]
As the silane coupling agent, for example, any one of chlorosilane, alkoxysilane, silazane, and a special silylating agent can be used. Specifically, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, methyl Triethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltriethoxysilane, decyltrimethoxysilane, hexamethyldisilazane, N, O- (bistrimethylsilyl) acetamide, N, N- (trimethylsilyl) ) Urea, tert-butyldimethylchlorosilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysila , Γ-methacryloxypyrrolyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercaptopropyl Examples include trimethoxysilane and γ-chloropropyltrimethoxysilane.
The amount of the hydrophobizing agent varies depending on the kind of the inorganic oxide fine particles and cannot be generally defined, but is usually about 5 to 50 parts by weight with respect to 100 parts by weight of the inorganic oxide fine particles.
[0054]
The electrostatic charge image developer of the present invention is desirably used in the range of 2 to 15 parts by weight of toner with respect to 100 parts by weight of carrier.
[0055]
【Example】
Examples of the present invention will be described below, but the present invention is not limited to these examples. In the following description, “parts” means “parts by weight” unless otherwise noted. The measurement method used in the present invention will be described below.
[0056]
<Measurement of fatty acid metal salt coating>
Sample particles are dispersed in a two-component mixed epoxy solution and left to stand for one day to solidify. Then, a section having a thickness of 100 nm is prepared with a microtome.
The section is placed on a copper mesh, set in a high resolution electron microscope JEM-2010 (manufactured by JEOL Ltd.), and photographed at 500,000 times with an applied voltage of 200 kV. Print the negative 3 times to 10 times.
Next, based on the photograph obtained by printing, the surface of the particle having a cross section of 10 particles is observed arbitrarily, and the surface covering state (coating thickness and covering rate) on the entire surface of the particle is evaluated. In addition, the coverage was calculated | required by the following Formula (1).
Formula (1) Coverage ratio = coating length / particle total surface length × 100 (%)
[0057]
<Toner shape factor SF1 (ML²/ A)>
In the present invention, the toner shape factor SF1 (ML²/ A) means the value represented by the following formula (2).²/ A = 100.
・ Formula (2) ML²/ A = (maximum length)²× π × 100 / (area × 4)
As a specific method for obtaining the shape factor, a toner image is taken from an optical microscope into an image analyzer (LUZEX III, manufactured by Nireco Corporation), and the equivalent circle diameter is measured. ML shown in the above formula (2) for the particles²Find the value of / A.
[0058]
<Charge amount measurement>
The charge amount in the actual machine evaluation test was measured with a TB200 manufactured by Toshiba under the conditions of a measurement environment of 25 ° C. and 55% RH by collecting the developer on the mag sleeve in the developing device.
[0059]
<Solid Area Density>
The image density was measured using X-Rite 938A (X-Rite).
[0060]
<Image quality>
Regarding the initial image quality, a chart having density gradation was copied, and the gradation, density uniformity, and presence / absence of an edge effect were visually evaluated. The image quality after copying 100,000 sheets was evaluated in terms of graininess, gradation / pseudo contour, density reproducibility, and other image quality defects.
[0061]
-Preparation of fatty acid metal salt-coated resin particles A-
3,000 parts of phenol resin particles (average particle size 0.5 μm, toluene insoluble) were introduced into an edge runner “MPUV-2 type” (product name, manufactured by Matsumoto Foundry Co., Ltd.) and methyltriethoxysilane (trade name: TSL8123) : Manufactured by Toshiba Silicone Co., Ltd.) A methyltriethoxysilane solution obtained by mixing and diluting 50 parts with 200 parts of ethanol was added to the phenol resin particles while the edge runner was operated, and the mixture was stirred.
[0062]
Next, 200 parts of zinc stearate powder was added over 10 minutes while operating the edge runner, mixed and stirred, and zinc stearate was deposited on the methyltriethoxysilane coating, followed by drying. Heat treatment was carried out at 105 ° C. for 60 minutes to obtain fatty acid metal salt-coated resin particles A.
The fatty acid metal salt-coated resin particles A had an average particle size of 0.7 μm, and the coating state was observed. As a result, the coating thickness was in the range of 1.0 to 40 nm, and 100% of the resin particle surface was coated.
[0063]
-Preparation of fatty acid metal salt-coated resin particles B-
3000 parts of cross-linked melamine resin particles (average particle size 0.3 μm, toluene insoluble) were introduced into an edge runner “MPUV-2” (product name, manufactured by Matsumoto Casting Co., Ltd.) and methyltriethoxysilane (trade name: A methyltriethoxysilane solution obtained by mixing and diluting 50 parts of TSL8123 (manufactured by Toshiba Silicone Co., Ltd.) with 200 parts of ethanol was added to the crosslinked melamine resin particles while operating the edge runner, and mixed and stirred.
[0064]
Next, 100 parts of calcium stearate is added over 10 minutes while the edge runner is running, mixed and stirred to deposit calcium stearate on the methyltriethoxysilane coating, and then drying is used. Heat treatment was carried out at 60 ° C. for 60 minutes to obtain fatty acid metal salt-coated resin particles B.
The fatty acid metal salt-coated resin particles B had an average particle size of 0.4 μm, and the coating state was observed. As a result, the coating thickness was in the range of 0.5 to 30 nm, and 100% of the resin particle surface was coated.
[0065]
-Adjustment of fatty acid metal salt coated conductive particles C-
Carbon black (average primary particle size 30 nm, DBP value 174 ml / 100 g, resistance 10⁰Ωcm: trade name VXC-72: manufactured by Cabot Corp. 1500 parts were introduced into the edge runner “MPUV-2” (product name, manufactured by Matsumoto Foundry Co., Ltd.) and methyltriethoxysilane (trade name: TSL8123: Toshiba) A methyltriethoxysilane solution obtained by mixing and diluting 50 parts (made by Silicone Co., Ltd.) with 200 parts of ethanol was added to the carbon black while operating the edge runner, followed by mixing and stirring.
[0066]
Next, 150 parts of zinc stearate are added over 10 minutes while the edge runner is running, mixed and stirred to deposit zinc stearate on the methyltriethoxysilane coating, and then dried using 105 parts. Heat treatment was carried out at 60 ° C. for 60 minutes to obtain fatty acid metal salt-coated conductive particles C.
The fatty acid metal salt-coated conductive particles C had an average primary particle size of 40 nm and the coating state was observed. As a result, the coating thickness was in the range of 0.5 to 40 nm, and 100% of the surface of the conductive particles was coated. .
[0067]
-Adjustment of fatty acid metal salt coated conductive particles D-
Just by changing the carbon black of fatty acid metal salt-coated conductive particles C to conductive powder (average particle size 0.2 μm, resistance 5-30 Ωcm: trade name Pastorlan-Type-IV: made by Mitsui Metals) The fatty acid metal salt-coated conductive particles D were formed.
The fatty acid metal salt-coated conductive particles D have an average particle size of 0.3 μm, and the coating state is observed. As a result, the coating thickness is in the range of 0.5 to 40 nm, and 100% of the surface of the conductive particles is coated. It was.
[0068]
-Manufacture of carrier A-
Ferrite particles (average particle size 45 μm): 100 parts
・ Toluene: 14 parts
Perfluorooctyl ethyl acrylate / methyl methacrylate copolymer: 1.6 parts
(Copolymerization ratio 40:60, Mw = 50,000)
Fatty acid metal salt-coated resin particles A: 0.3 part
Fatty acid metal salt coated conductive particles C: 0.12 parts
The above components excluding the ferrite particles are dispersed with a stirrer for 10 minutes to prepare a film-forming liquid, and the film-forming liquid and ferrite particles are placed in a vacuum degassing kneader and stirred at 60 ° C. for 30 minutes, and then the pressure is reduced. Then, toluene was distilled off to form a film on the surface of the ferrite particles to obtain a carrier.
[0069]
The perfluorooctylethyl acrylate copolymer used as the matrix resin in the coating was obtained because the fatty acid metal salt-coated resin particles A and the fatty acid metal salt-coated conductive particles C were diluted with toluene and dispersed in a sand mill. The fatty acid metal salt-coated resin particles A and the fatty acid metal salt-coated conductive particles C were uniformly dispersed in the coating on the carrier.
[0070]
-Manufacture of carrier B-
A film was formed by the same formulation as carrier A except that fatty acid metal salt-coated resin particles A were changed to fatty acid metal salt-coated resin particles B, and carrier B was obtained.
[0071]
―Manufacture of Carrier C―
A film was formed by the same formulation as Carrier A except that the fatty acid metal salt-coated conductive particles C were changed to the fatty acid metal salt-coated conductive particles D to obtain Carrier C.
[0072]
―Manufacture of Carrier D―
A film was formed by the same formulation as Carrier A except that the fatty acid metal salt-coated conductive particles C were changed to uncoated carbon black, and Carrier D was obtained.
[0073]
―Manufacture of Carrier E―
A film was formed by the same formulation as Carrier A except that the fatty acid metal salt-coated resin particles A were changed to uncoated phenol resin particles, and Carrier E was obtained.
[0074]
―Manufacture of Carrier F―
A coating is formed with the same formulation as carrier A except that fatty acid metal salt-coated resin particles A and fatty acid metal salt-coated conductive particles C are replaced with uncoated phenol resin particles and uncoated carbon black. Obtained.
[0075]
-Manufacture of carrier G-
A film was formed by the same formulation as Carrier F except that uncoated phenolic resin particles were removed, and Carrier G was obtained.
[0076]
―Manufacture of Carrier H―
A film was formed by the same formulation as Carrier F except that uncoated carbon black was removed, and Carrier H was obtained.
[0077]
―Manufacture of Carrier I―
Form a film with the same formulation as Carrier A except that the fatty acid metal salt-coated resin particles A and the fatty acid metal salt-coated conductive particles C were removed to make the perfluorooctylethyl acrylate / methyl methacrylate copolymer 2.0 parts by weight. Carrier I was obtained.
[0078]
-Colored particle A manufacturing method-
・ Styrene-n-butyl acrylate resin: 100 parts
(Tg = 58 ° C., Mn = 4000, Mw = 25000)
Cyan pigment (Pigment Blue 15: 3): 3 parts
The above mixture is kneaded with an extruder, pulverized with a jet mill, and then dispersed with a wind classifier to obtain a Cyan toner A having a volume average particle diameter D50 = 5.0 μm and SF1 (ML2 / A) of 148.8. It was.
[0079]
-Colored particle B production method-
<Adjustment of resin dispersion (1)>
・ Styrene: 370 parts
N-butyl acrylate: 30 parts
・ Acrylic acid: 8 parts
・ Dodecanethiol: 24 parts
・ Carbon tetrabromide: 4 parts
6 parts of nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.) and anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 10 parts dissolved in 550 parts of ion-exchanged water was emulsified and dispersed in a flask, and 50 parts of ion-exchanged water in which 4 parts of ammonium persulfate was dissolved was added thereto while slowly mixing for 10 minutes. After carrying out nitrogen substitution, the inside of the flask was stirred and heated in an oil bath until the contents reached 70 ° C., and emulsion polymerization was continued for 5 hours. As a result, a resin dispersion liquid (1) in which resin particles having an average particle diameter of 155 nm, Tg = 59 ° C., and weight average molecular weight Mw = 12000 was dispersed was obtained.
[0080]
<Adjustment of resin dispersion (2)>
・ Styrene: 280 parts
N-butyl acrylate: 120 parts
・ Acrylic acid: 8 parts
6 parts of nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.) and anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 12 parts dissolved in 550 parts of ion-exchanged water was emulsified and dispersed in a flask. While slowly mixing for 10 minutes, 50 parts of ion-exchanged water in which 3 parts of ammonium persulfate was dissolved was added thereto. After carrying out nitrogen substitution, the inside of the flask was stirred and heated in an oil bath until the contents reached 70 ° C., and emulsion polymerization was continued for 5 hours. As a result, a resin dispersion liquid (2) in which resin particles having an average particle diameter of 105 nm, Tg = 53 ° C., and weight average molecular weight Mw = 550000 was dispersed was obtained.
[0081]
<Preparation of colored dispersion>
Cyan pigment (Pigment Blue 15: 3): 70 parts
・ Nonionic surfactant: 5 parts
(Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.)
・ Ion exchange water: 200 parts
A coloring dispersant in which the above components are mixed, dissolved, and dispersed for 10 minutes using a homogenizer (Ultra Turrax T50: manufactured by IKA) to disperse colorant (Cyan pigment) particles having an average particle diameter of 250 nm. (2) was adjusted.
[0082]
<Releasing agent dispersion>
Paraffin wax: 50 parts
(HNP0190: Nippon Seiwa Co., Ltd., melting point 85 ° C.)
Cationic surfactant: 5 parts
(Sanisol B50: manufactured by Kao Corporation)
The above components were dispersed in a round stainless steel flask using a homogenizer (Ultra Turrax T50: manufactured by IKA) for 10 minutes, and then dispersed with a pressure discharge type homogenizer, so that the average particle size was 550 nm. A release agent dispersion (1) in which the mold agent particles were dispersed was prepared.
[0083]
<Adjustment of aggregated particles>
-Resin dispersion (1): 120 parts
-Resin dispersion (2): 80 parts
Colorant dispersion: 200 parts
-Mold release dispersion (1): 40 parts
Cationic surfactant: 1.5 parts
(Sanisol B50: manufactured by Kao Corporation)
The above components were mixed and dispersed in a round stainless steel flask using a homogenizer (Ultra Turrax T50: manufactured by IKA), and then heated to 50 ° C. while stirring the inside of the flask in an oil bath for heating. . After maintaining at 45 ° C. for 20 minutes, it was confirmed with an optical microscope that it was confirmed that aggregated particles having an average particle diameter of about 4.3 μm were formed. Further, 60 parts of the resin dispersion (1) as a resin-containing fine particle dispersion was gently added to the dispersion. The temperature of the heating oil bath was raised to 50 ° C. and held for 30 minutes. When observed with an optical microscope, it was confirmed that adhered particles having an average particle diameter of about 4.5 μm were formed.
[0084]
<Creation of colored particles B>
After adding 3 parts of an anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) to the particle dispersion, the inside of the stainless steel flask is sealed, and stirred up to 105 ° C. using a magnetic seal. Heated and held for 4 hours. Then, after cooling, the reaction product is filtered, washed thoroughly with ion-exchanged water, and dried to obtain a Cyan toner having SF1 (ML2 / A) of 130 and volume average particle diameter D50 = 5.6 μm. It was.
[0085]
<Examples 1-6 and Comparative Examples 1-4>
Volume average primary particle diameter of 100 parts of toners A and B each treated with 1.3 parts of hydrophobic silica (RX50: manufactured by Nippon Aerosil Co., Ltd.) having a volume average primary particle diameter of 50 nm and 10% decyltrimethoxysilane. Toner was obtained by mixing 0.7 parts of 20 nm titanium oxide (MT-150A: manufactured by Teica) at a peripheral speed of 32 m / s for 10 minutes using a Henschel mixer and sieving at 45 μm to remove coarse powder.
6 parts of the toner and 94 parts of carriers A to I were mixed in the combinations shown in Table 2 to prepare developers. Using these electrostatic charge image developers, a copy test was performed with an electrophotographic copying machine (DCC500CP modified machine, manufactured by Fuji Xerox Co., Ltd.).
Table 2 below shows a list of carriers prepared, and Table 2 shows combinations of toner particles and carriers in Examples 1 to 6 and Comparative Examples 1 to 4. Table 3 shows the evaluation results of Examples 1 to 6 and Comparative Examples 1 to 4.
[0086]
[Table 1]

[0087]
[Table 2]

[0088]
[Table 3]

[0089]
In Table 3, “* 1”, “* 2”, “* 3”, and “* 4” in the “image quality” column mean the following.
* 1: Image density measured with X-Rite 938 is low (less than 1.0)
* 2: Image blank / carrier scattering
* 3: Streaks due to remaining photoconductor
* 4 Edge effect / pseudo contour, etc.
[0090]
In Table 3, “G0” to “G5” in the “Transferability” column are grade evaluations of transferability by observing the toner remaining on the photoreceptor, and G0 means the most excellent transferability. However, transferability deteriorates with increasing numbers, and G5 means the worst transferability. It should be noted that G0 to G2 were set at a level having no practical problem.
[0091]
【The invention's effect】
As described above, according to the present invention, in a carrier in which a core material made of a magnetic material is coated with a resin at least on its surface, at least one type of resin particles or conductive particles is dispersed in the carrier coating resin. A carrier for an electrostatic charge image developer, wherein at least one of the resin particles or the conductive particles is coated with a fatty acid metal salt, and a developer using the carrier, In addition, the charging property, transfer property and cleaning property are excellent, and stable image quality maintenance can be realized.

Claims (5)

The surface of the core material made of a magnetic substance Te carrier odor coated with resin,
It is dispersed containing particles one or more selected from the resin particles and conductive particles prior Symbol resin, one of said distributed content is composed of particles, the particle surface is coated with an alkoxysilane or polysiloxane, then A carrier for an electrostatic charge image developer, the surface of which is coated with a fatty acid metal salt.   2. The electrostatic charge image developer carrier according to claim 1, wherein the surface of the dispersed particles is coated with a fatty acid metal salt component to a thickness of 0.5 to 50 nm.   The electrostatic charge image developer carrier according to claim 1, wherein the dispersed particles are resin particles made of a nitrogen-containing resin.   The electrostatic image development according to any one of claims 1 to 3, wherein the dispersed particles are carbon black, metal, metal oxide, and / or a composite thereof. Agent carrier. In an electrostatic charge image developer composed of a carrier and a toner,
The toner has a shape factor SF1 (ML ² / A) in the range of 100 to 140, the carrier includes a core material made of a magnetic material, and a resin coating layer that covers the surface of the core material, and the resin One or more kinds of particles selected from resin particles and conductive particles are dispersed and contained in the coating layer, and one kind of the dispersed particles is coated with alkoxysilane or polysiloxane on the particle surface, An electrostatic charge image developer, which is a carrier whose surface is coated with a fatty acid metal salt component.