JP3883875B2 - Magnetic toner and image forming apparatus - Google Patents

Description

【０１０３】
さらに、複写画像と原稿画像の色差ΔEを算出した。この結果を表2に示す。
【表２】

【０１０４】
(実施例2)気化させたメタクリル酸メチルに、気化させたシアン顔料(Pigment Blue 15.3)を混合して、実施例1のシリカ/チタニア被覆磁性体粒子の表面にプラズマ重合反応によって膜形成し、シアン色のシリカ/チタニア/メタクリル酸メチル/シアン顔料被覆磁性体粒子を得た。
【０１０５】
これをシリカ/チタニア/メタクリル酸メチル被覆磁性体粒子の代りに用いて、実施例1同様に処理してシアン色磁性トナー粒子を得て、同様に表1に示すようなL*、a*、b*の測定結果を、また表2に示すようなΔEの測定結果を得た。
【０１０６】
(実施例3)気化させたメタクリル酸メチルに、気化させたマゼンタ顔料(Pigment Red 122)を混合して、実施例1のシリカ/チタニア被覆磁性体粒子の表面にプラズマ重合反応によって膜形成し、マゼンタ色のシリカ/チタニア/メタクリル酸メチル/マゼンタ顔料被覆磁性体粒子を得た。
【０１０７】
これをシリカ/チタニア/メタクリル酸メチル被覆磁性体粒子の代りに用いて、実施例1同様に処理してマゼンタ色磁性トナー粒子を得て、同様に表1に示すようなL*、a*、b*の測定結果を、また表2に示すようなΔEの測定結果を得た。
【０１０８】
(実施例4)気化させたメタクリル酸メチルに、気化させたイエロー顔料(Pigment Yellow 180)を混合して、実施例1のシリカ/チタニア被覆磁性体粒子の表面にプラズマ重合反応によって膜形成し、イエロー色のシリカ/チタニア/メタクリル酸メチル/イエロー顔料被覆磁性体粒子を得た。
【０１０９】
これをシリカ/チタニア/メタクリル酸メチル被覆磁性体粒子の代りに用いて、実施例1同様に処理してイエロー色磁性トナー粒子を得て、同様に表1に示すようなL*、a*、b*の測定結果を、また表2に示すようなΔEの測定結果を得た。
【０１１０】
(比較例1)平均粒径0.25μmの磁性体粒子(戸田工業製MAT305)をシリカ/チタニア/メタクリル酸メチル被覆磁性体粒子の代りに用いて、実施例1同様に処理してトナー粒子を得て、同様に表1に示すようなL*、a*、b*の測定結果を、また表2に示すようなΔEの測定結果を得た。
【０１１１】
【発明の効果】
本発明によって、従来の技術よりも、短時間で容易に製造でき、かつ磁性体粒子自体の色を隠蔽し、鮮やかな白色または色彩を帯びた被覆性磁性体粒子を含有することを特徴とするトナーおよびその製造方法を提供することができる。
【０１１２】
さらに、このトナーを用いてトナー像を形成することができる画像形成装置を提供することができる。
【図面の簡単な説明】
【図１】 被覆磁性体粒子の拡大概念図。
【図２】 被覆磁性体粒子の形状の一例を示す断面図。
【図３】 画像形成装置の1実施形態の概念図。
【図４】 画像形成装置の別の実施形態の概念図。
【図５】 トナーの概念図。
【符号の説明】
１・・・感光体ドラム、
２・・・帯電装置、
３・・・潜像形成装置、
４・・・現像装置、
５・・・転写装置、
６・・・クリーニング装置、
７・・・トナーカートリッジ
８・・・プロセスカートリッジ、
３１・・・磁性材料からなる粒子、
３２・・・第1の金属酸化物結晶、
３３・・・第2の金属酸化物結晶、
３４・・・被覆膜、
３５・・・着色コーティング層、
５０・・・被覆性磁性体粒子、
６０・・・バインダ剤、
７０・・・トナー粒子。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic toner used for an electrophotographic toner, a magnetography toner, a magnetic printing ink, and the like, and relates to a covering magnetic toner that conceals the color of magnetic particles and has a clear color, and a method for producing the same.
[0002]
[Prior art]
Conventionally, one-component magnetic toners are generally known in which magnetic particles such as Fe3O4, γ-Fe2O3, or barium ferrite are kneaded and pulverized with a binder and a colorant.
[0003]
Since the magnetic particles are black or brown, the color of the toner becomes dull when it is converted into a toner, and a clear and faithful color image cannot be formed.
[0004]
For this reason, Japanese Patent Application Laid-Open No. 6-102696 discloses a toner using magnetic particles in which an inorganic metal compound layer having a high refractive index that hides the original color such as black and brown is formed by a precipitation reaction and a method for producing the same.
[0005]
Further, Japanese Patent Application Laid-Open No. 9-329915 discloses a toner in which a light-interfering multilayer film is formed on the surface of magnetic particles and the color of the magnetic particles themselves is concealed, and a method for producing the same.
[0006]
[Problems to be solved by the invention]
The above conventional techniques have the following problems.
[0007]
That is, in the technique disclosed in Japanese Patent Application Laid-Open No. 6-102696, it is necessary to reduce the diameter of the precipitated crystals in order to smooth the surface of the inorganic metal compound layer, and in order to obtain small crystals, precipitation is required. Since the speed has to be slowed down, the time required for production has become longer.
[0008]
In the technique described in Japanese Patent Application Laid-Open No. 9-329915, it is difficult to adjust the film thickness, and the color has changed greatly with only slight deviation.
[0009]
OBJECT OF THE INVENTION
The present invention is characterized in that it contains coated magnetic particles that can be easily manufactured in a shorter time than the above-described conventional technology, and that conceal the color of the magnetic particles themselves and have a bright white color or a color. It is an object of the present invention to provide a toner and a manufacturing method thereof.
[0010]
It is another object of the present invention to provide an image forming apparatus capable of forming a toner image using this toner.
[0011]
[Means for Solving the Problems]
In the toner of the present invention, particles made of a magnetic material, a first metal oxide crystal formed on the surface of the particles, and a second metal oxide crystal that levels the unevenness of the first metal oxide crystal And a layer made of a light-transmitting substance having a refractive index smaller than the first and second refractive indexes, formed on the surface of the second metal oxide crystal.
[0012]
In this way, by separating the crystal precipitation twice, first, large crystals are quickly precipitated, and fine crystals are formed later to fill in the irregularities of the first crystals, so that the magnetic particles can be obtained in a shorter time than conventional techniques. It is possible to provide a toner characterized by concealing its own color and containing white covering magnetic particles and a toner containing the same.
[0013]
Moreover, it has the layer which consists of a monomer formed in the surface of the layer which consists of the said transparent substance.
[0014]
By the layer made of this monomer, the first and second metal oxide crystals are protected, and coated magnetic particles having increased gloss and a toner containing the same can be provided.
[0015]
Moreover, it has the layer which consists of a monomer and a coloring agent formed in the surface of the layer which consists of the said monomer.
[0016]
By having a layer comprising this monomer and a colorant, it is easier to manufacture in a shorter time than conventional techniques, and the magnetic particles themselves conceal the color of the magnetic particles, and the coated magnetic particles are brilliantly colored. It is possible to provide a toner characterized by containing the above.
[0017]
In the toner production method of the present invention, on the surface of the particles made of a magnetic material,
[0018]
First, a white first metal oxide having a first refractive index is deposited, and then, on the surface of the first metal oxide crystal, the crystal particle diameter is smaller than that of the first metal oxide crystal. Precipitating a white second metal oxide having a second refractive index to level the unevenness due to the crystal of the first metal oxide, and the refractive index is smaller than the first and second refractive indices. And a layer made of a light-transmitting substance having a rate.
[0019]
In this way, by separating the crystal precipitation twice, first, large crystals are quickly precipitated, and fine crystals are formed later to fill in the irregularities of the first crystals, so that the magnetic particles can be obtained in a shorter time than conventional techniques. It is possible to provide a covering magnetic particle having a vivid white color and a toner containing the same, concealing its own color.
[0020]
Further, a layer made of a monomer is formed on the surface of the layer made of the light-transmitting substance.
[0021]
Accordingly, it is possible to provide a coatable magnetic particle having a bright white color and a toner containing the same.
[0022]
In addition, a layer made of a monomer and a colorant is formed on the surface of the layer made of the light-transmitting substance.
[0023]
As a result, it is possible to provide coatable magnetic particles having a vivid color and a toner containing the same.
[0024]
In addition, the layer composed of the monomer and the colorant is formed by plasma polymerization.
[0025]
As a result, a layer composed of the monomer and the colorant can be formed thinly and uniformly, and a coatable magnetic particle having a bright and uniform color and a toner containing the same can be provided.
[0026]
In the image forming apparatus of the present invention, a particle made of a magnetic material, a first metal oxide crystal formed on the surface of the particle, and a second metal oxide that levels the unevenness of the first metal oxide crystal Since the electrostatic latent image formed on the image carrier is developed using the toner containing the product crystal and the coated magnetic particles having the crystal, a clear color image can be obtained.
[0027]
Further, since the toner cartridge and the process cartridge containing the toner are used, it is easy to replenish the toner in the image forming apparatus capable of obtaining a vivid color electrophotographic image.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
In the magnetic toner of the present embodiment, a white metal oxide is crystallized on the surface of particles made of a magnetic material to form a first crystal, and the second crystal that fills the unevenness of the crystal is converted into a white metal oxide. The coated magnetic particles coated with a material having a low refractive index and transmitting light, and further coated with a plasma polymerization layer of a coating monomer and a colorant, are dispersed in a binder agent. It is.
[0029]
FIG. 1 is an enlarged conceptual view of the coated magnetic particle 50 of the present embodiment. The particles 31 made of a magnetic material are not necessarily spherical in nature, and the first metal oxide crystal 32 and the second metal oxide crystal 33 are not necessarily independent crystals, For example, it may look like Figure 2.
[0030]
The particles made of a magnetic material are, for example, a metal exhibiting ferromagnetism such as Fe, Co, or Ni, or a metal alloy or compound represented by a general formula of, for example, MO.Fe2O3 or MFe2O4.
[0031]
Here, M corresponds to, for example, divalent or monovalent metal ions such as Mn, Fe, Ni, Co, Cu, Mg, Zn, Cd, and Li.
[0032]
Specific examples of these magnetic iron compounds include silicon steel, permalloy, sendust, Fe-Co, alnico alloys, magnetite, γ-iron oxide, Mn-Zn ferrite, Ni-Zn ferrite, and Mn-Mg ferrite. And iron-based oxides exhibiting magnetism, such as Li-based ferrite and Cu-Zn-based ferrite.
[0033]
The average particle diameter is preferably 1 μm or less, more preferably 0.1 to 0.5 μm. This is a size convenient for dispersing in the binder agent when the toner is formed.
[0034]
Further, the shape is not necessarily a spherical shape as shown in FIG.
[0035]
The first metal oxide crystal formed on the surface of the particles made of this magnetic material has a high refractive index, and a white one is used as a base for a colored layer to be applied to the toner to improve color development.
[0036]
Examples of such substances include titanium oxide, zirconium oxide, bismuth oxide, cerium oxide, antimony oxide, and indium oxide, but are not limited to these, and any white metal oxide with a high refractive index may be used.
[0037]
These deposit the particles on the surface of the magnetic material by a metal alkoxide method described in JP-A-6-228604, an aqueous method described in JP-A-11-131102, and other conventional methods.
[0038]
The alkoxide method will be briefly described.
[0039]
For example, particles made of a magnetic material serving as a core are dispersed in an alkoxide solution containing a metal element that is a component of the metal oxide crystal as described above. When the alkoxide is hydrolyzed, the metal oxide is deposited on the surface of the core material. Since the metal oxide crystal thus obtained has a fine and homogeneous composition, it is easy to increase the crystal film thickness.
[0040]
The aqueous method will be briefly described.
[0041]
Particles made of a magnetic material serving as a core are dispersed in a buffer solution. And the aqueous solution of the salt of the metal element which is a component of the above metal oxide crystal | crystallization is dripped gently. Then, the crystal of the metal oxide is precipitated on the surface of the particle made of the magnetic material. Also by this method, the crystal film has a fine and homogeneous composition.
[0042]
Crystals are precipitated on the surface of the particles made of the magnetic material by the above method, but since these are still amorphous, they are fired (300 to 1200 ° C., 0.1 to 50 hours).
[0043]
The crystal particle diameter of the crystal thus obtained is usually about 1 to 500 nm. The crystal film thickness is preferably 0.05 to 0.25 μm. If the film thickness is thinner than this, the color is transparent, and if it is thick, the particles become too large.
[0044]
Since the surface of the crystal film formed as described above is an aggregate of crystals, gaps and irregularities are formed. As a result, the light is irregularly reflected, resulting in a dull white color.
[0045]
In order to prevent irregular reflection, the gaps and irregularities are filled, and the second metal oxide crystal to make the crystal film smoother than the crystal film itself is a high refractive index white metal oxide crystal with a gap between the crystals. A substance that can be a fine crystal that can be filled is used.
[0046]
Examples of such a material include silicon oxide and titanium oxide, but are not limited to these. The material is white with a high refractive index and fine enough to fill the gaps and irregularities of the first metal oxide crystal film. Any metal oxide that can be crystallized may be used.
[0047]
These are deposited by the metal alkoxide method, the water-based method, and other conventional methods in the same manner as the above-mentioned crystallized particles are deposited, or formed by dropping a solution of the metal oxide raw material on the toner and then firing. .
[0048]
On this, a coating film made of a low refractive index and light-transmitting substance is formed for the purpose of protecting the crystal film and further smoothing the surface.
[0049]
Examples of such substances include metal oxides (zinc oxide, aluminum oxide, cadmium oxide, titanium oxide, zirconium oxide, tantalum oxide, silicon oxide, antimony oxide, neodymium oxide, lanthanum oxide, bismuth oxide, cerium oxide, tin oxide, and oxide. Magnesium, lithium oxide, lead oxide, etc.), metal sulfides (cadmium sulfide, zinc sulfide, antimony sulfide, etc.), metal selenides (cadmium selenide), metal tellurides (cadmium telluride), metal fluorides (calcium fluoride) Sodium fluoride, trisodium aluminum fluoride, lithium fluoride, magnesium fluoride) and the like.
[0050]
These are deposited on the crystal film by a vapor deposition method such as a PVD method, a CVD method, or a spray drying method.
[0051]
The coating film is, for example, cellulose, polyamide, epoxy resin, polyester, melamine resin, polyurethane, vinyl acetate resin, silicon resin, acrylate ester, methacrylate ester, styrene, ethylene, propylene, and polymers of these derivatives, Alternatively, an organic material such as a copolymer may be used.
[0052]
These can be formed by a polymerization method in a liquid layer or a vapor deposition method similar to metal oxide deposition.
[0053]
Neither a metal compound nor an organic substance is limited to these substances, and any substance having a low refractive index and a light transmission property may be used.
[0054]
After the coating film is formed as described above, the monomer and the colorant are plasma polymerized to form a colored coating layer to obtain coated magnetic particles.
[0055]
Examples of the monomer used include silicon-based monomers of organic silicon such as hexamethyldisiloxane, trimethoxysilane, tetramethylsilane, tetramethyldisiloxane, hexamethyldisilazane, hexamethylcyclotrisilazane, diallylaminotrimethylsilane, and trivinylsilane. And various monomers such as unsaturated hydrocarbon monomers such as acetylene, ethylene, propylene, butene, butadiene, cyclohexane, benzene and toluene, fluorocarbon monomers such as tetrafluoroethylene, and vinyl monomers such as styrene and methyl methacrylate. However, the present invention is not limited to these, and may be a mixture of a plurality of types of monomers.
[0056]
The colorant used is, for example, Fast Yellow G, Benzidine Yellow, Indian Fast Orange, Irgadine Red, Carmine FR, Permanent Bordeaux FRR, Pigment Orange R, Resol Red 2G, Lake Red C, Rhodamine FB, Rhodamine B Lake, Phthalocyanine Examples thereof include blue, pigment blue, brilliant green B, phthalocyanine green, and quinacridone, but are not limited to these, and conventional colorants are used alone or in combination.
[0057]
The monomer and the colorant are vaporized separately and formed on the coating film by plasma polymerization.
[0058]
However, the silicon monomer can be vaporized by mixing the monomer and the colorant.
[0059]
The plasma polymerization will be briefly described.
[0060]
After the vaporized monomer / colorant mixture is introduced into the reaction vessel, the inside of the reaction vessel is depressurized.
[0061]
In the reaction vessel, a pair of upper and lower electrode plates are provided, with the upper electrode plate serving as an anode and the lower electrode plate serving as a cathode. The cathode electrode plate can be vibrated with a vibration device.
[0062]
The particles made of the magnetic material after the formation of the coating film are exposed to the air-fuel mixture activated by the high-frequency plasma discharge between the upper and lower electrodes while being placed on the lower electrode plate and being vibrated.
[0063]
The activated air-fuel mixture causes a polymerization reaction on the surface of the coated magnetic particles to form a thin and uniform colored coating layer.
[0064]
Even if it says a coloring coating layer, it is not necessary to color, if the color of a coating film or a coating layer should just remain.
[0065]
The particles made of the coated magnetic material obtained as described above have magnetism as a magnetic material and color as a colorant.
[0066]
This is dispersed by a conventional toner manufacturing method in a binder agent together with additives such as a charge control agent, other colorants, a release agent, and an external additive as necessary to form a toner.
[0067]
For example, as the least restrictive method, there is a pulverization method in which a mixture of a binder agent raw material, coated magnetic particles, and other additives is melt-kneaded in a thermal kneader and then mechanically pulverized.
[0068]
In addition, after spraying a solution in which a binder agent raw material, coated magnetic particles and other additives are dispersed and dissolved to produce fine particles, the spray drying method of classifying the particles and performing other post-treatments are: There is an advantage that fine and nearly spherical toner particles can be produced.
[0069]
Furthermore, the polymerization method in which the binder agent raw material, the coated magnetic particles and other additives are dispersed in the polymerizable polymer and polymerized by a method such as emulsion polymerization, suspension polymerization, dispersion polymerization, etc., yields fine and nearly spherical particles. In addition, the number of steps can be reduced.
[0070]
The magnetic toner thus prepared is used as a one-component developer for color. It can also be used as a two-component developer by mixing with a carrier.
[0071]
These one-component developer and two-component developer can be used as a developer of an image forming apparatus by a conventional method.
[0072]
For example, an image forming apparatus using the developer according to the present embodiment can be configured as shown in FIG.
[0073]
A charging device 2, a latent image forming device 3, a developing device 4, a transfer device 5, and a cleaning device 6 are provided around the photosensitive drum 1 serving as a circular image carrier.
[0074]
The photoreceptor layer covering the surface of the photoreceptor drum 1 is made of, for example, OPC, α-Si, zinc oxide or the like.
[0075]
The charging device 2 is a device that makes the potential of the photoreceptor layer uniform by applying a charge by corona discharge or the like.
[0076]
The latent image forming apparatus 3 exposes the uniform photoreceptor layer to form a latent image. For example, a laser beam is emitted by combining a light emitter such as an LED or a lens.
[0077]
The developing device 4 develops the latent image by supplying charged toner to the photoreceptor layer on which the latent image is formed.
[0078]
Here, since the toner containing the particles of the covering magnetic material that conceals the original color and has a bright white color is used in this embodiment, the developed toner image has a white color or a bright color. It will be.
[0079]
The transfer device 5 transfers the toner image on the photosensitive drum 1 to a sheet 7 positioned between the photosensitive drum 1 by electrically sucking the toner image.
[0080]
The cleaning device 6 removes the toner remaining on the photosensitive drum 1 after the transfer, and prepares for the next image formation. As a method for removing the toner, there are an electrical method in which the photosensitive drum 1 is exposed to light to control the potential and the toner is dropped, and a mechanical method in which a plate is applied to the photosensitive drum 1 and the toner is scraped off.
[0081]
The image thus obtained is white or has a vivid color.
[0082]
The toner supply to the developing device 4 can be easily performed by replacing the emptied toner cartridge 7 with one filled with toner.
[0083]
Alternatively, the photosensitive drum 1, the developing device 4, and the cleaning device 6 may be integrated, and a process cartridge structure may be used in which replacement is performed when toner replenishment is necessary. In this way, the photosensitive drum 1 that affects the reproducibility of the formed image can be replaced at the toner replacement timing together with the process cartridge 8 before the surface is significantly deteriorated due to the surface being damaged.
[0084]
Hereinafter, examples and comparative examples of the toner according to the exemplary embodiment will be described.
[0085]
Example 1 Particles made of a magnetic material having an average particle size of 0.25 μm (MAT305 manufactured by Toda Kogyo Co., Ltd.) were treated as follows.
[0086]
Buffer solution 1 was prepared by dissolving potassium chloride in distilled water to a concentration of 0.4 mol / liter and boric acid to a concentration of 0.4 mol / liter.
[0087]
Next, sodium hydroxide was dissolved in distilled water to a concentration of 0.4 mol / liter to obtain a buffer solution 2.
[0088]
Further, 250 ml of buffer solution 1 and 115 ml of buffer solution 2 were mixed to obtain buffer solution 3.
[0089]
In addition, acetic acid was dissolved in distilled water to a concentration of 0.3 mol / liter, and sodium acetate was dissolved to a concentration of 0.9 ml / liter to obtain buffer solution 4.
[0090]
In 365 ml of buffer solution 3, 15 g of particles made of a magnetic material were placed and stirred with an ultrasonic vibrator to obtain dispersion 1.
[0091]
After adding 20 ml of sodium silicate solution to the dispersion at 40 ml / min, the mixture was allowed to stand for 2 hours to precipitate silica crystals on the surface of the particles made of a magnetic material to obtain silica-coated magnetic particles.
[0092]
Thereafter, it was washed with water, kept at 150 ° C. with a dryer, and dried for 8 hours to obtain silica-coated magnetic particles.
[0093]
5.5 g of this silica-coated magnetic particle was taken, placed in 250 ml of buffer solution 4, and vibrated with an ultrasonic vibrator to obtain dispersion 2.
A 0.6 mol titanium sulfate aqueous solution was added dropwise to the dispersion 2 maintained at 50 to 55 ° C., and after the reaction was completed, titania crystals were precipitated on the surface of the silica-coated magnetic particles.
[0095]
This was washed with water, dried in a vacuum dryer, heated and calcined at 500 ° C. for 30 minutes to obtain yellowish white, smooth surface silica / titania coated magnetic particles.
[0096]
The silica / titania-coated magnetic particles were spread on the electrode plate on the lower side of the reaction vessel of the plasma polymerization apparatus so as to have a thickness of about 1 mm, and then the pressure inside the reaction vessel was reduced. Vaporized methyl methacrylate monomer was introduced, 13.56MHz, 500W high frequency power was applied between the upper and lower electrode plates to cause plasma discharge for 2 to 10 minutes, and at the same time, the lower electrode plate was vibrated with a vibration device, Silica / titania coated magnetic particles were vibrated.
[0097]
In this way, a film of methyl methacrylate was formed on the surface of the silica / titania-coated magnetic particles by plasma polymerization reaction, and white silica / titania / methyl methacrylate-coated magnetic particles were obtained.
[0098]
50 parts of the silica / titania / methyl methacrylate coated magnetic particles, 49 parts of styrene acrylic resin (CPR100 manufactured by Mitsui Chemicals), and 1 part of a charge control agent (TN-105 manufactured by Hodogaya Chemical) were prepared.
[0099]
These were mixed and dispersed with a high-speed fluid mixer, and then heat-melt kneaded to obtain a kneaded mass.
[0100]
The kneaded mass was pulverized and classified to obtain white magnetic toner particles having an average particle diameter of 10 μm.
[0101]
The toner particles were mounted on a copying machine (modified from TOSHIBA TEC TF631), and the original image was copied to obtain a copied image.
[0102]
A colorimetric color difference meter (TC8600A manufactured by Tokyo Denshoku Co., Ltd.) was used to determine the color measurement result of this copy image based on JISZ8722 (1982) based on the method specified by the CIE (International Lighting Association), and L *, a * , B * are displayed in the standard color system. The results are shown in Table 1.
[Table 1]

[0103]
Further, the color difference ΔE between the copied image and the original image was calculated. The results are shown in Table 2.
[Table 2]

[0104]
(Example 2) Vaporized methyl methacrylate was mixed with vaporized cyan pigment (Pigment Blue 15.3) to form a film on the surface of silica / titania-coated magnetic particles of Example 1 by a plasma polymerization reaction. Cyan colored silica / titania / methyl methacrylate / cyan pigment coated magnetic particles were obtained.
[0105]
This was used in place of silica / titania / methyl methacrylate coated magnetic particles, and treated in the same manner as in Example 1 to obtain cyan magnetic toner particles. Similarly, L *, a *, as shown in Table 1, b * measurement results and ΔE measurement results as shown in Table 2 were obtained.
[0106]
(Example 3) Vaporized methyl methacrylate was mixed with vaporized magenta pigment (Pigment Red 122) to form a film on the surface of silica / titania-coated magnetic particles of Example 1 by a plasma polymerization reaction. Magenta silica / titania / methyl methacrylate / magenta pigment coated magnetic particles were obtained.
[0107]
This was used in place of silica / titania / methyl methacrylate coated magnetic particles, and processed in the same manner as in Example 1 to obtain magenta magnetic toner particles. Similarly, L *, a *, as shown in Table 1, b * measurement results and ΔE measurement results as shown in Table 2 were obtained.
[0108]
(Example 4) Vaporized methyl methacrylate was mixed with vaporized yellow pigment (Pigment Yellow 180) to form a film on the surface of silica / titania-coated magnetic particles of Example 1 by a plasma polymerization reaction. Yellow colored silica / titania / methyl methacrylate / yellow pigment coated magnetic particles were obtained.
[0109]
This was used in place of silica / titania / methyl methacrylate coated magnetic particles, and treated in the same manner as in Example 1 to obtain yellow magnetic toner particles. Similarly, L *, a *, as shown in Table 1, b * measurement results and ΔE measurement results as shown in Table 2 were obtained.
[0110]
(Comparative Example 1) Using magnetic particles (MAT305 manufactured by Toda Kogyo Co., Ltd.) having an average particle diameter of 0.25 μm instead of silica / titania / methyl methacrylate coated magnetic particles, toner particles were obtained in the same manner as in Example 1. Similarly, measurement results of L *, a *, and b * as shown in Table 1 and ΔE measurement results as shown in Table 2 were obtained.
[0111]
【The invention's effect】
According to the present invention, it is characterized in that it can be manufactured more easily in a shorter time than the prior art, and the magnetic particles themselves are concealed in color and contain bright white or colored covering magnetic particles. A toner and a manufacturing method thereof can be provided.
[0112]
Furthermore, an image forming apparatus capable of forming a toner image using this toner can be provided.
[Brief description of the drawings]
FIG. 1 is an enlarged conceptual diagram of coated magnetic particles.
FIG. 2 is a cross-sectional view showing an example of the shape of coated magnetic particles.
FIG. 3 is a conceptual diagram of an embodiment of an image forming apparatus.
FIG. 4 is a conceptual diagram of another embodiment of the image forming apparatus.
FIG. 5 is a conceptual diagram of toner.
[Explanation of symbols]
1 ... photosensitive drum,
2 ... charging device,
3 ... latent image forming device,
4 ... Developing device,
5 ... Transfer device,
6 ... Cleaning device,
7 ... Toner cartridge 8 ... Process cartridge,
31 ... Particles made of magnetic material,
32 ... 1st metal oxide crystal,
33 ... second metal oxide crystal,
34 ... coating film,
35 ... colored coating layer,
50: Covering magnetic particles,
60 ... Binder agent,
70: Toner particles.

Claims (2)

A toner obtained by melting and kneading magnetic particles in a binder resin and then pulverizing the toner,
The magnetic particles are
A magnetic material of 0.1 to 0.5 μm serving as a core material;
A white first metal oxide crystal layer selected from silica, titanium oxide, zirconium oxide, bismuth oxide, cerium oxide, antimony oxide, and indium oxide, formed on the surface of the magnetic material by crystallization;
A white second metal oxide crystal layer selected from silicon oxide and titanium oxide formed by crystallization on the surface of the first metal oxide crystal layer;
Cellulose, polyamide, epoxy resin, polyester, memine resin, polyurethane, vinyl acetate resin, silicon resin, acrylate ester, methacrylate ester, styrene, ethylene, propylene, which covers the surface of the second metal oxide crystal layer And a coating layer selected from a polymer or copolymer of these derivatives,
A magnetic toner comprising a colored coating layer formed on a surface of the coating layer and formed by plasma polymerization of a monomer and a colorant. A charging device for charging the image carrier;
An exposure device that forms an electrostatic latent image by exposing the image carrier charged by the charging device;
A developing device for developing the electrostatic latent image formed by the exposure device by supplying toner;
A transfer device for transferring the toner image developed by the developing device to a sheet;
The toner is obtained by melting and kneading magnetic particles in a binder resin and then pulverizing,
The magnetic particles are
A magnetic material of 0.1 to 0.5 μm serving as a core material;
A white first metal oxide crystal layer selected from silica, titanium oxide, zirconium oxide, bismuth oxide, cerium oxide, antimony oxide, and indium oxide, formed on the surface of the magnetic material by crystallization;
A white second metal oxide crystal layer selected from silicon oxide and titanium oxide formed by crystallization on the surface of the first metal oxide crystal layer;
Cellulose, polyamide, epoxy resin, polyester, memine resin, polyurethane, vinyl acetate resin, silicon resin, acrylate ester, methacrylate ester, styrene, ethylene, propylene, which covers the surface of the second metal oxide crystal layer And a coating layer selected from a polymer or copolymer of these derivatives,
An image forming apparatus comprising: a colored coating layer formed on the surface of the coating layer by plasma polymerization of a monomer and a colorant.

Images