JP4311053B2 - Dry toner for developing electrostatic latent image, developer and image forming method - Google Patents

Description

【０１５０】
本発明の、疎水化表面処理されたカルシウム化合物粒子を含有するトナーを用いた現像剤は、実施例１〜５結果のように帯電環境安定性が良好であり、転写性が良好であった。また、１０万枚コピー後に感光体を抜き出し、表面観察を行ったところ、傷、汚染は軽微であった。
【表２】

【０１５１】
一方、カルシウム化合物粒子を含有しない、または疎水化処理されていない炭酸カルシウムを満たさないトナーの現像剤は、比較例１，２，３の結果のように帯電環境安定性がやや悪く、更に画像部の、特に線画像部のトナーのチラバリがあり不十分な画質であった。また、１０万枚コピー後に感光体を抜き出し、表面観察を行ったところ、比較例１においては、傷、トナー汚染が顕著だった。比較例２，３においても、トナー汚染が顕著だった。
【０１５２】
また上記システムのクリーニングブレードを除去し、ブラシを付加し、帯電装置をロール帯電装置に変更して実施例５Ｋｕｒｏを検討した。
【０１５３】
その結果、初期は勿論２万枚コピー後も初期同様鮮明な画像を呈し、画像上の問題は発生しなかった。
【０１５４】
さらに上記システムにおいてブレード及びブラシクリーニングを一切用いないでスコロトロン帯電器を用いて実施例５Ｋｕｒｏを検討した。
【０１５５】
その結果、初期は勿論２万枚コピー後も初期同様鮮明な画像を呈し、画像上の問題は発生しなかった。
【０１５６】
【発明の効果】
本発明の静電潜像現像用トナー、現像剤及び画像形成方法によれば、帯電特性や転写性の安定な維持という顕著な効果を得ることができる。
【図面の簡単な説明】
【図１】 本発明の実施例および比較例に用いたキャリアの体積固有抵抗を求めるための装置構成を示す模式図である。
【図２】 トナーチラバリの評価時のソリッド画像形成を示す模式図である。
【符号の説明】
１ ガード電極、２ 上部電極、３ 測定試料、４ 下部電極、５ 試料保持リング、６ エレクトロメーター。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toner, a developer, a manufacturing method, and an image forming method used for developing an electrostatic latent image in electrophotography and electrostatic recording.
[0002]
[Prior art]
In the electrophotographic method, an electrostatic latent image formed on a latent image carrier (photoconductor) is developed with a toner containing a colorant, and the resulting toner image is transferred onto a transfer member, which is heated on a roll or the like. The latent image carrier is cleaned to form an electrostatic latent image again. The dry developer used in such electrophotography is a one-component developer using a toner in which a colorant or the like is blended in a binder resin, and a two-component developer in which a carrier is mixed with the toner. Broadly divided. One-component developer uses magnetic powder, transported to developing carrier by magnetic force, and develops magnetic one component to be developed and non-magnetic to transport and develop to developing carrier by applying charging such as charging roll without using magnetic powder Can be classified into one component. Since the latter half of the 1980s, the market for electrophotography has been strongly demanded for miniaturization and high functionality with the key to digitization, and in particular, high-quality prints close to high-quality printing and silver halide photography are desired for full color image quality.
[0003]
Digitization processing is indispensable as a means for achieving high image quality, and the effect of digitization related to such image quality is that complex image processing can be performed at high speed. This makes it possible to control characters and photographic images separately, and the reproducibility of both qualities is greatly improved compared to analog technology. In particular, for photographic images, gradation correction and color correction are possible, and this is advantageous over analog in terms of gradation characteristics, definition, sharpness, color reproduction, and graininess. However, on the other hand, it is necessary to faithfully form a latent image created by an optical system as an image output, and as a toner, an activity aimed at faithful reproduction has been accelerated as the particle diameter is increasingly reduced. However, it is difficult to stably obtain high image quality simply by reducing the particle size of the toner, and improvement of basic characteristics in development, transfer, and fixing characteristics is more important.
[0004]
In particular, in a color image, three or four color toners are superimposed to form an image. Therefore, if any one of these toners exhibits different characteristics from the initial stage in terms of development, transfer, and fixing, or performance different from other colors, it may cause a decrease in color reproduction, or a deterioration in image quality such as a deterioration in graininess and color unevenness. Become. In order to maintain a stable high-quality image over time as in the initial stage, it is important how to stably control the characteristics of each toner.
[0005]
When making a copy, the dry developer develops the electrostatic latent image formed on the photoconductor with these developers, transfers the toner on the photoconductor, and then cleans the toner remaining on the photoconductor. Is. Therefore, the dry developer needs to satisfy various conditions in the copying process, particularly in the developing process or the cleaning process. That is, the toner is used for development in the form of individual particles, not as agglomerates, even during development. For this purpose, the toner has sufficient fluidity and fluidity or electrical properties are not deteriorated over time. It is necessary not to change depending on the target or environment (temperature, humidity). Further, in the two-component developer, it is necessary to prevent the phenomenon that the toner is fixed on the carrier surface, so-called toner filming.
[0006]
Further, in cleaning, a cleaning property is required such that residual toner is easily detached from the surface of the photoreceptor. In order to satisfy these requirements, in a dry developer, an inorganic fine powder such as silica, an organic fine powder such as fatty acid, its metal salt and derivatives thereof, a fluororesin fine powder or the like is externally added to the toner, or a two-component developer. Various developers have been proposed to improve fluidity, durability or cleaning properties. However, in the conventionally proposed additives, inorganic compounds such as silica, titania, and alumina remarkably improve the fluidity, but the surface layer of the photoreceptor is easily dented and scratched by the hard inorganic compound fine powder, and the damaged part. Therefore, there is a problem that toner sticking is likely to occur.
[0007]
In order to solve these problems, it has been proposed to externally add additives such as silica and titanium oxide, or those whose surfaces are hydrophobized with an organic silane compound or coated with an inorganic oxide. (For example, see Patent Documents 1 to 4). Although these provide some improvement in storage stability (blocking resistance), transportability, developability, transferability, chargeability, etc., in the current situation where further higher image quality is required, especially for the surface layer of the photoreceptor. Suppression of damage and control of charging characteristics are not sufficient. For example, generally used silica-based fine powder has a strong negative polarity, and excessively increases the chargeability of a negatively chargeable toner, particularly at low temperatures and low humidity, while moisture at high temperatures and high humidity. Since the chargeability is reduced by taking in, there is a problem that a large difference is caused in the chargeability between the two. As a result, density reproduction failure and background fogging may occur. In addition, silica and titanium oxide have high Mohs hardness, and when they are released from the toner surface, defects such as photoconductor scratches are caused.
[0008]
For example, since calcium carbonate is softer than materials such as silica, titanium oxide, and alumina, it is difficult to dent or damage the surface phase of the photoreceptor, and the toner containing calcium carbonate can be prevented from sticking. (For example, see Patent Documents 5 and 6). Calcium compound particles, like silica, differ in charging behavior under low temperature and low humidity and high temperature and high humidity, but do not show strong negative chargeability like silica, so surface-treated calcium carbonate is used as a charge control agent. In addition, toners added as fluidizing agents have also been proposed (see, for example, Patent Documents 7 to 10). However, these proposals have insufficient charge control, and there is a difference in charging behavior between low temperature and low humidity and high temperature and high humidity, and environmental stability is insufficient to provide high image quality in various office environments. It was.
[0009]
Recently, there is a high demand for colorization, especially on-demand printing, and there is a technique for forming a multicolor image on a transfer belt to cope with high-speed copying, transferring the multicolor image to an image fixing material at a time, and fixing it. Has been reported (for example, see Patent Document 11). If the process of transferring from the photoconductor to the transfer belt is the primary transfer, and the process of transferring from the transfer belt to the transfer body is the secondary transfer, the transfer is repeated twice, and a technique for improving the transfer efficiency becomes more and more important. In particular, in the case of secondary transfer, a multicolor image is transferred at once, and since the transfer body (for example, in the case of paper, its thickness, surface property, etc.) changes variously, charging, developing, It is necessary to control transferability extremely high.
[0010]
In addition, in order to reduce power consumption, space, and obtain a high-quality image, a technique is disclosed in which each color is transferred to an intermediate transfer member and fixed to the transfer member at the same time as transfer (for example, Patent Documents 12 and 13 are disclosed). reference). The important point here is that the transfer belt needs to have both a transfer function and a fixing function. In other words, it is necessary to improve transferability in the cooled state in the primary transfer portion, and to transfer heat instantaneously in the secondary transfer simultaneous fixing portion, so that the belt material should be a thin layer belt with high heat resistance. Become. Here, as functions required for the toner, it is required to provide a toner that adapts to low-pressure fixing because the transfer efficiency is controlled to be extremely high and a strong pressure cannot be applied at the time of fixing. In addition, since the belt surface also has a transfer function, it is important to minimize toner contamination during fixing and scratches due to external additives as much as possible.
[0011]
On the other hand, a method has been proposed in which the volume resistivity of the carrier is controlled to faithfully reproduce high image quality, particularly halftone, solid black, and characters (see, for example, Patent Documents 14, 15, and 16). In any of these methods, the resistance is adjusted depending on the type of carrier coating layer and the coating amount, and initially the target volume resistivity is obtained and high image quality is exhibited, but the carrier coating layer is exposed to stress in the developing device. Peeling occurs and the volume resistivity changes greatly. Therefore, it is difficult to achieve high image quality over a long period of time.
[0012]
On the other hand, a method of adjusting the volume resistivity by adding carbon black to the carrier coating layer has been proposed (for example, see Patent Document 17).
[0013]
Although the change in volume resistivity due to the peeling of the coating layer can be suppressed by this method, the external additive or toner component added to the toner adheres to the carrier and changes the volume resistivity of the carrier. It was difficult to develop high image quality for a long time like other carriers.
[0014]
[Patent Document 1]
JP-A-4-204750
[Patent Document 2]
JP-A-6-208241
[Patent Document 3]
JP 7-295293 A
[Patent Document 4]
JP-A-8-160659
[Patent Document 5]
JP-A-8-190221
[Patent Document 6]
JP 2002-287411 A
[Patent Document 7]
JP-A-5-346682
[Patent Document 8]
JP-A-8-227171
[Patent Document 9]
JP-A-11-174734
[Patent Document 10]
JP 2002-156778 A
[Patent Document 11]
JP-A-8-115007
[Patent Document 12]
Japanese Patent Laid-Open No. 10-213977
[Patent Document 13]
JP-A-8-44220
[Patent Document 14]
JP 56-125751 A
[Patent Document 15]
Japanese Patent Laid-Open No. 62-267766
[Patent Document 16]
Japanese Patent Publication No. 7-120086
[Patent Document 17]
JP-A-4-40471
[0015]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances of the prior art. By applying a surface treatment with a coupling agent or / and silicone oil in addition to an organic acid to the calcium compound, the charging characteristics such as the charge level and environmental differences are improved, and the Mohs hardness is higher than that of silica, alumina, titania, etc. By using a small calcium compound, it is possible to suppress dents and scratches on the surface layer of the photoreceptor for a long period of time. An object of the present invention is to satisfy toner flowability, chargeability, developability, transferability, cleaning property, and fixability at the same time for a long period of time, and collect residual toner on a latent image carrier using an electrostatic brush. Toner for developing electrostatic latent image with improved trouble, toner for developing electrostatic latent image with improved trouble of collecting residual toner on latent image carrier after transfer again in developing machine for electrostatic latent image, A manufacturing method and an electrostatic latent image developer using the same are provided. Another object of the present invention is to provide an image forming method capable of developing, transferring and fixing in response to high image quality requirements.
[0016]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors have found that the above object can be achieved by using specific inorganic compound particles in the toner, and the present invention has been completed. It was.
[0017]
Specifically:
[0018]
(1) In a dry toner for developing an electrostatic latent image having at least a binder resin and a colorant as components, at least the surface of the toner has One organic acid metal salt selected from the group consisting of sodium erucate, sodium oleate, sodium stearate, or sodium palmitate A dry toner composition for developing an electrostatic latent image, further comprising calcium compound particles hydrophobized with a coupling agent and / or silicone oil.
[0019]
(2) The electrostatic image dry toner composition as described in (1) above, wherein the toner contains a release agent.
[0020]
(3) The dry toner composition for developing an electrostatic latent image according to the above (1), wherein the calcium compound particles to be surface-treated are calcium carbonate, hydroxyapatite, or calcium sulfoaluminate.
( 4 The dry toner composition for developing an electrostatic latent image according to (1), wherein the coupling agent is n-decyltrimethoxysilane.
( 5 The dry toner composition for developing an electrostatic latent image according to (1), wherein the silicone oil is dimethylpolysiloxane.
[0021]
( 6 ) The above (1) to (1), wherein the amount of the treating agent for the calcium compound particles is 2 to 30% by weight with respect to 100% by weight of the calcium compound particles. 5 The electrostatic charge image dry toner composition described in any one of (1).
[0022]
( 7 (1) to (1), wherein the calcium compound particles contain 0.05 to 1.5% by weight with respect to 100% by weight of the toner particles. 6 The toner composition for developing an electrostatic latent image described in any one of (1).
[0023]
( 8 (1) to (1) above, wherein the toner has a weight average particle diameter of 2 to 8 μm and an average shape index SF1 of 100 to 140. 7 The electrostatic charge image dry toner composition described in any one of (1).
[Equation 1]
SF1 = (ML ² / A) × (π / 4) × 100
Here, ML is the absolute maximum length of the particles, and A is the projected area of the particles, and these are quantified mainly by analyzing a microscope image or an operation electron microscope image with an image analyzer.
[0024]
( 9 (1) to (1) above, wherein the toner is a color toner. 8 4) The electrostatic image dry color toner composition according to any one of 1).
[0025]
( 10 ) In the developer for developing an electrostatic latent image comprising a carrier and a toner composition, the carrier has a resin coating layer in which a conductive material is dispersed and contained in a matrix resin on a core material, and the toner composition is bonded. Containing at least a resin and a colorant, on the surface of the toner composition, One organic acid metal salt selected from the group consisting of sodium erucate, sodium oleate, sodium stearate, or sodium palmitate And a developer containing calcium compound particles hydrophobized with a coupling agent and / or silicone oil.
[0026]
( 11 The above toner is characterized in that the toner contains a release agent. 10 The developer for developing an electrostatic latent image described in 1).
[0027]
( 12 The above-mentioned (characterized in that the calcium compound particles are calcium carbonate particles) 10 ) Or ( 11 The developer for developing an electrostatic latent image described in 1).
[0028]
( 13 ) The above-mentioned (2), wherein the amount of the treating agent for the calcium compound particles is 2 to 30% by weight with respect to 100% by weight of the calcium compound particles. 10 ) To ( 12 The developer for developing an electrostatic latent image according to any one of (1).
[0029]
( 14 The above toner is characterized in that a toner having a weight average particle diameter of 2 to 8 μm and an average shape index SF1 of 100 to 140 is used. 10 ) To ( 13 The developer for developing an electrostatic latent image according to any one of (1).
[0030]
( 15 ) A charging means for charging the latent image carrier, a latent image forming means for exposing the charged latent image carrier to form an electrostatic latent image, and development for developing the electrostatic latent image using toner. And an image forming apparatus having a transfer separating means for transferring the formed toner image to a recording material and separating it from the latent image carrier, and a fixing means for fixing the transferred toner image on the recording material. In the image forming method for forming an image, the toner comprises at least a binder resin and a colorant as components, and at least the surface of the toner has One organic acid metal salt selected from the group consisting of sodium erucate, sodium oleate, sodium stearate, or sodium palmitate In addition, calcium compound particles hydrophobized with a coupling agent and / or silicone oil are contained, and the transfer separation means develops each color toner on a latent image carrier and transfers it to a transfer belt or transfer drum. A color image forming method, wherein the toner of each color is transferred to a transfer body at a time.
[0031]
( 16 ) A charging means for charging the latent image carrier, a latent image forming means for exposing the charged latent image carrier to form an electrostatic latent image, and development for developing the electrostatic latent image using toner. Means, transfer separation means for transferring the formed toner image to a recording material and separating it from a latent image carrier which is a toner image holding body, and cleaning means for removing toner remaining on the toner image holding body after transfer. In the image forming method of forming an image using an image forming apparatus having a fixing unit for fixing the transferred toner image on a recording material, the toner includes at least a binder resin and a colorant as components. At least on the toner surface One organic acid metal salt selected from the group consisting of sodium erucate, sodium oleate, sodium stearate, or sodium palmitate In addition to calcium compound particles hydrophobized with a coupling agent and / or silicone oil, the cleaning means carries a latent image using an electrostatic brush without rubbing the latent image carrier with a blade. An image forming method comprising collecting residual toner on a body.
[0032]
( 17 ) In an image forming method for forming an image using an image forming apparatus that collects residual toner on the latent image carrier again in the developing machine without rubbing the latent image carrier with a blade, the toner includes at least Containing binder resin and colorant as components, at least on the surface of the toner One organic acid metal salt selected from the group consisting of sodium erucate, sodium oleate, sodium stearate, or sodium palmitate An image forming method comprising calcium compound particles hydrophobized with a coupling agent and / or silicone oil.
[0033]
( 18 ) A charging means for charging the latent image carrier, a latent image forming means for exposing the charged latent image carrier to form an electrostatic latent image, and development for developing the electrostatic latent image using toner. In the image forming method of forming an image using an image forming apparatus, the image forming apparatus includes: a toner image forming apparatus; Contains at least a binder resin and a colorant as components, and at least on the surface of the toner. One organic acid metal salt selected from the group consisting of sodium erucate, sodium oleate, sodium stearate, or sodium palmitate In addition to calcium compound particles hydrophobized with a coupling agent and / or silicone oil, and the transfer fixing separation means develops each color toner on a latent image carrier and transfers it to a transfer belt. A method of forming a color image, wherein each color is fixed to a transfer body at the same time as transferring.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
Next, the toner in the present invention will be described.
[0035]
<Electrostatic charge image dry toner composition>
A toner composition (hereinafter also simply referred to as “toner”) contains calcium compound particles that have been subjected to a hydrophobic treatment on the surface of the toner.
[0036]
The hydrophobic treatment is performed by adding an organic acid and a coupling agent and / or silicone oil. The weight ratio of the organic acid to the coupling agent and / or silicone oil is preferably 1/20 to 1/4. If it is less than 1/20, the environmental difference is not sufficiently improved, and if it exceeds 1/4, the charge level is insufficient (low).
[0037]
As the organic acid, a fatty acid-based surface treatment agent, for example, a higher fatty acid having 6 to 22 carbon atoms, specifically, fats and oils such as beef tallow, pig oil, coconut oil, palm oil, rapeseed oil, castor oil, soybean oil and the like are used as raw materials. Saturated or unsaturated fatty acids obtained as described above, lauric acid, myristic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, hydroxy fatty acid, caproic acid, caprylic acid, palmitic acid, behenic acid, palmitoleic acid Erucic acid, alkali metal salts such as sodium salts and potassium salts, alkaline earth metal salts and esters such as magnesium salts and calcium salts, and the like. Alternatively, resin acid-based surface treatment agents such as abietic acid, repopimaric acid, neoabietic acid, pultrinic acid, dehydroapitic acid, dihydroabietic acid, tetraabietic acid, dextropimaric acid, isodextropimaric acid and the like can be mentioned. These alkali metal salts, alkaline earth metal salts, esters and the like can be mentioned. In addition to these, hydrogenated rosin, disproportionated rosin, polymerized rosin, rosin ester, maleated rosin, maleated rosin ester, rosin-modified phenol, etc. can be mentioned as resin acid derivatives, these alkali metal salts, Examples include alkaline earth metal salts or esters. Organic phosphoric acid surface treatments such as nonionic phosphates, carboxylic acid surface treatments such as aromatic carboxylic acids, acrylic acid α, β monoester unsaturated carboxylic acid salts or esters thereof Sulfonic acid surface treatment agents such as dodecylbenzene sulfonic acid, α-olefin sulfone, organic polymers such as oxalic acid, citric acid, tartaric acid, etc. Examples include acids and sulfonic acid acids or salts such as lauryl sulfate.
[0038]
These may be used alone or in combination of two or more. Among these, it is preferable to use an alkali metal salt or ammonium salt of a higher fatty acid, an alkaline earth metal salt, or a higher fatty acid or an ester thereof.
[0039]
Examples of the coupling agent include a silane coupling agent, a titanate coupling agent, and an aluminate coupling agent.
[0040]
As the silicone oil, for example, dimethyl silicone oil, alkyl-modified silicone oil, chlorophenyl silicone oil, fluorine-modified silicone oil, amino-modified silicone oil and the like can be used.
[0041]
Particularly preferably, in addition to an alkali metal salt or ammonium salt of a higher fatty acid, an alkaline earth metal salt, or a higher fatty acid or an ester thereof, a silane coupling agent or various silicone oils can be used.
[0042]
The surface treatment of calcium carbonate can be either dry or wet, but the surface treatment is preferably performed in a state where the calcium carbonate is dispersed in a slurry. The slurry can be prepared, for example, by dispersing calcium carbonate (powder) in a solvent such as water, toluene, xylene, hexane, and the like, but a water slurry is more preferable. The amount of dispersion (slurry concentration: solid content) in this case is not particularly limited, but is usually about 0.1 to 50% by weight, preferably 1 to 20% by weight.
[0043]
The surface treatment method of calcium carbonate, in the case of dry type, by using a batch type mixer such as a super mixer, a continuous mixer such as a ribbon blender, a kneader, etc., and mixing at a temperature above the melting point of the surface treatment agent, It is possible to uniformly treat the surface. In the case of a wet process, it is preferable to use a known stirring mixer such as a normal paddle, a disper, or a turbine blade to treat with a hot water slurry of calcium carbonate. The temperature (liquid temperature) in the case of mix | blending is not restrict | limited in particular, Usually, it is good about 10-80 degreeC. The organic acid surface treatment agent can uniformly form an organic acid adsorption layer (coating layer) on the surface of calcium carbonate by performing the surface treatment in a dissolved or emulsified state.
[0044]
When processing with a second treating agent such as a coupling agent and / or silicone oil after the first treating agent such as an organic acid, after blending the first treating agent, filtration, centrifugation, and filter press are performed as necessary. The solid content may be recovered according to a known solid-liquid separation method such as, and the solid content may be further subjected to a treatment such as drying or pulverization, if necessary. As the dryer, for example, a hot air box type dryer, a band dryer, a spray dryer or the like is used. The dried first treatment agent-coated calcium carbonate particles are finely adjusted to a desired particle size and pore volume by pulverization in some cases. These operations may be performed according to known conditions. In the present invention, any of the slurry after blending the first treating agent, the wet cake after solid-liquid separation, and the solid after drying can be treated with the second treating agent. The method for forming the second treating agent layer is not particularly limited as long as the second layer can be formed on the first layer. For example, a method of adding and mixing the second treating agent to any of the slurry after the first treating agent blending as described above, the wet cake after solid-liquid separation, and the solid after drying, and solidifying the second treating agent by spraying. Any of the method of giving to a minute, the method of making the vaporized 2nd processing agent contact solid content, etc. may be sufficient. Also, a method of blowing a gas such as air or nitrogen into the heated liquid second treatment agent and bringing the second treatment agent into contact with the first treatment agent-coated calcium carbonate particles together with the gas, a liquid second treatment agent, The second treatment agent-coated calcium carbonate particles are added to the first treatment agent-coated calcium carbonate particles, and the mixture of the first treatment agent-coated calcium carbonate particles and the second treatment agent-coated calcium carbonate particles are heated and uniformly contacted with each other. The treatment agent can be coated on the surface of the first treatment agent-coated calcium carbonate particles. Moreover, it is also possible to process a 2nd processing agent simultaneously in the process process by a 1st processing agent. After coating with the second treatment agent, the solid content may be recovered according to a known solid-liquid separation method such as filtration and centrifugation, and further, the solid content may be subjected to treatment such as drying and pulverization as necessary. good. These operations may be performed according to known conditions.
[0045]
In the present invention, as described above, it is preferable to contain calcium compound particles treated with a coupling agent and / or silicone oil and hydrophobized in addition to the organic acid, and the surface treatment amount is also limited. Although not necessarily, the total amount of the coupling agent and / or silicone oil in addition to the organic acid, which is the surface treatment agent, is preferably 2.0 to 30 wt% with respect to 100 wt% of the calcium compound particles. . When the surface treatment agent is less than 2.0 wt% with respect to 100 wt% of the calcium compound particles, the surface treatment effect cannot be obtained, and when it is more than 30 wt%, aggregated particles are generated.
[0046]
Further, the amount of calcium compound particles subjected to the hydrophobic treatment as described above is preferably 0.05 to 1.5% by weight with respect to 100% by weight of the toner. When the amount of the calcium compound particles subjected to the hydrophobization treatment is less than 0.05% by weight, the environment dependency of the toner is not sufficiently improved, and when it is more than 1.5% by weight, the fluidity of the toner is deteriorated and the charge is maintained. Sexual deterioration is inevitable.
[0047]
Calcium compounds such as calcium carbonate are softer than materials such as silica, titanium oxide, and alumina, so they do not easily dent or damage the surface phase of photoconductors, transfer belts, and fixing belts. And fixing ability can be satisfied at the same time for a long time. By subjecting the calcium compound particles to a hydrophobic treatment, an excessive increase in charge can be suppressed, the charge level can be controlled to be low, and the difference in charge behavior between low temperature and low humidity and high temperature and high humidity can be made minute. That is, the environmental dependency of the toner can be improved without adversely affecting the frictional charging property of the toner. By incorporating calcium compound particles that have been subjected to a hydrophobization treatment on the surface, these effects can be effectively extracted.
[0048]
The effect of improving the environment dependency of the toner is increased by including calcium compound particles subjected to organic acid treatment as a hydrophobic treatment on the surface. In addition, the dispersibility of the calcium compound particles subjected to the organic acid treatment is particularly excellent, and it is possible to suppress variation in charging between toner particles. Further, since the change in the toner surface composition over time (such as loosening of aggregates) is small, the charging stability is superior to other treatment agent treatments. Further, since there are few aggregates of calcium compounds on the toner surface, in addition to being soft, it exhibits a great effect in suppressing damage to the photoreceptor and the like. Further, by applying a coupling agent and / or silicone oil in addition to the organic acid, the environment dependency is further reduced, and in addition, the charge level can be controlled. After the organic acid treatment, the coupling agent and / or silicone oil treatment may be performed, or the organic acid treatment and the coupling agent and / or silicone oil treatment may be performed simultaneously.
[0049]
A method for producing a calcium compound according to the present invention will be described.
[0050]
The calcium compound in the present invention is a calcium compound synthesized from lime milk that is a calcium hydroxide aqueous suspension, calcium dihydrogen phosphate, calcium hydrogen phosphate, tricalcium phosphate, hydroxyapatite, fluorapatite, etc. And calcium phosphate and calcium sulfoaluminate.
[0051]
As the production method, calcium compounds are produced by blowing carbon dioxide into lime milk which is an aqueous suspension of calcium hydroxide (Japanese Patent Publication No. 37-519, Japanese Patent Publication No. 47-22944, Japanese Patent Publication No. 56-). No. 40118) is known. Calcium phosphate is a method in which α-type tricalcium phosphate is formed, and then a phosphate compound is converted into water in a system in which agar or sodium dodecylbenzenesulfonate is added (Kanazawa Takafumi). Ed., Inorganic phosphorus chemistry, 168-170) or a method of reacting lime milk and aqueous phosphoric acid while grinding, or a method of producing fine hydroxyapatite which is calcium phosphate by grinding after mixing 62-4324 gazette etc.) are known. Calcium sulfoaluminate is a method in which an aqueous solution of lime milk and aluminum sulfate is instantaneously mixed and reacted at about 40 ° C. with a high-speed, high shear mixing stirrer (Japanese Patent Laid-Open No. 53-14692). Are known. In these methods, the dispersibility indicating the particle size of the powder filler, such as rubber, plastic, paint, ink, etc., and the powder filler obtained by drying the slurry filler in the solvent are again obtained. Strict temperature control of reaction system, addition of third substances such as organic and inorganic substances, milling, etc. to improve properties such as redispersibility, which indicates how much to disperse when dispersed in a solvent The crystal particle diameter, crystal particle shape, etc. are adjusted by the mechanochemical reaction by high shear force.
[0052]
The specific embodiment of the manufacturing method of the calcium compound obtained by this invention is demonstrated.
[0053]
(1) Synthesis of calcium compounds
Methods for producing calcium compounds by blowing carbon dioxide into lime milk can be classified into two types according to the conditions of carbonation. As a normal condition, one is a cubic particle called a colloidal calcium compound having an average particle diameter of 0.1 μm or less, and usually in lime milk having a calcium hydroxide concentration of 15% or less at a compound start temperature of 25 ° C. or less. Carbon dioxide can be reacted at a blowing rate of 2.0 L / min or more in terms of 100% carbon dioxide per 1 kg of calcium hydroxide. The other is a spindle-shaped particle called a light calcium compound having an average particle size of 0.5 μm or more. In lime milk having a calcium hydroxide concentration of 15% or more, a carbon dioxide gas is converted into calcium hydroxide at a compound start temperature of 25 ° C. or more. By reacting at a blowing rate of 2.0 L / min or less in terms of 100% carbon dioxide gas per 1 kg, a desired particle size / particle shape can be obtained.
[0054]
(2) Synthesis of calcium phosphate
Hydroxyapatite, a kind of calcium phosphate, has a Ca / P molar ratio of about 1.6 to 1.7 while stirring lime milk having a calcium hydroxide concentration of 4 to 20% by weight (the stoichiometric molar ratio is 1.67), a wet compounding method in which an aqueous solution of phosphoric acid or a salt thereof is gradually added.
[0055]
(3) Synthesis of calcium sulfoaluminate
Calcium sulfoaluminate is usually prepared by adding an aqueous solution of aluminum sulfate having an aluminum sulfate concentration of about 5 to 30% by weight to lime milk having a calcium hydroxide concentration of about 4 to 20% by weight. ₂ O _Three Can be added and reacted so that the molar ratio is 6-8.
[0056]
The average particle diameter of the calcium compound particles can be appropriately set according to the use of the final product, etc., but the primary particle diameter is usually about 0.005 to 10 μm, preferably 0.005 to 1.0 μm, most preferably. In the range of 0.005 to 0.07 μm may be used.
[0057]
In the present invention, the hydrophobized calcium compound particles are added to the toner particles and mixed. The mixing can be performed by a known mixer such as a V-type blender, a Henschel mixer, or a Redige mixer.
[0058]
In this case, various additives may be added as necessary. Examples of these additives include other known fluidizing agents such as organic particles and inorganic particles, and cleaning aids or transfer aids such as polystyrene fine particles, polymethyl methacrylate fine particles, and polyvinylidene fluoride fine particles.
[0059]
Further, as an external addition method to the toner, the calcium compound particles and the other additives may be added and mixed at the same time.
[0060]
Moreover, it does not matter even if it goes through a sieving process after external addition mixing.
[0061]
The toner for developing an electrostatic latent image is composed of a binder resin, a colorant, and a release agent, and a toner of 2 to 8 μm can be used.
[0062]
By using a toner having an average shape index SF1 of 100 to 140, an image with high development, transferability and high image quality can be obtained.
[Expression 2]
SF1 = (ML ² / A) × (π / 4) × 100
Here, ML is the absolute maximum length of the particles, and A is the projected area of the particles, and these are quantified mainly by analyzing a microscope image or an operation electron microscope image with an image analyzer.
[0063]
The toner used in the present invention is not particularly limited by the production method as long as it satisfies the above average shape index and particle size, and a known method can be used.
[0064]
The toner can be produced, for example, by kneading, pulverizing, and classifying a binder resin and a colorant, and if necessary, a release agent, a charge control agent, and the like. A method of changing the shape by force or heat energy, emulsion polymerization of a polymerizable monomer of a binder resin, a dispersion formed, and a dispersion of a colorant, if necessary, a release agent, a charge control agent, etc. Are mixed, agglomerated and heat-fused to obtain toner particles, an emulsion polymerization agglomeration method, a polymerizable monomer and a colorant for obtaining a binder resin, a release agent, a charge control agent, etc., if necessary. Suspension polymerization method in which the solution is suspended in an aqueous solvent for polymerization, a binder resin and a colorant, and if necessary, a solution such as a release agent and a charge control agent is suspended in an aqueous solvent for granulation. Turbidity method 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.
[0065]
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-anhydrous. Mention may be made of maleic acid copolymers, polyethylene, polypropylene and the like. Further examples include polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like.
[0066]
In addition, toner colorants include magnetic powders such as magnetite and ferrite, carbon black, aniline blue, caryl 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.
[0067]
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.
[0068]
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.
[0069]
<Developer>
The developer according to the present invention comprises the above-described toner composition and a carrier described below.
[0070]
On the other hand, the carrier is a resin-coated carrier having a resin coating layer in which a conductive material is dispersed and contained in a matrix resin on a core material.
[0071]
Matrix resins include polyethylene, polypropylene, polystyrene, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic acid copolymer. Examples include polymers, straight silicone resins composed of organosiloxane bonds or modified products thereof, fluororesins, polyesters, polyurethanes, polycarbonates, phenol resins, amino resins, melamine resins, benzoguanamine resins, urea resins, amide resins, epoxy resins, etc. However, it is not limited to these. Examples of the conductive material include metals such as gold, silver and copper, and titanium oxide, zinc oxide, barium sulfate, aluminum borate, potassium titanate, tin oxide, and carbon black. Is not to be done.
[0072]
The content of the conductive material is preferably 1 to 50 parts by weight and more preferably 3 to 20 parts by weight with respect to 100 parts by weight of the matrix resin.
[0073]
Examples of the carrier core material include magnetic metals such as iron, nickel and cobalt, magnetic oxides such as ferrite and magnetite, and glass beads. However, in order to adjust the volume resistivity using the magnetic brush method, a magnetic material is used. Preferably there is.
[0074]
The average particle diameter of the core material is generally 10 to 500 μm, preferably 30 to 100 μm.
[0075]
As a method for forming the resin coating layer on the surface of the carrier core material, an immersion method in which the carrier core material is immersed in a coating layer forming solution containing a matrix resin, a conductive material and a solvent, or a coating layer forming solution is used as the carrier. Spray method for spraying on the surface of the core material, fluidized bed method for spraying the coating layer forming solution in a state where the carrier core material is suspended by fluid air, mixing the carrier core material and the coating layer forming solution in a kneader coater, A kneader coater method for removing the solvent may be mentioned.
[0076]
The solvent used in the coating layer forming solution is not particularly limited as long as it dissolves the matrix resin. For example, aromatic hydrocarbons such as toluene and xylene, and ketones such as acetone and methyl ethyl ketone. , Ethers such as tetrahydrofuran and dioxane can be used.
[0077]
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. .
[0078]
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 ^Four In the range of V / cm, 10 ⁶ -10 ¹⁴ It is preferably Ωcm. The carrier volume resistivity is 10 ⁶ If 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 10 ¹⁴ If it is larger than Ωcm, black solid and halftone reproduction will be worse. In addition, the amount of carriers transferred to the photoconductor increases, and the photoconductor is easily damaged. The electrostatic brush may be made of a resin containing a conductive filler such as carbon black or metal oxide or a fibrous material coated on the surface, but is not limited thereto.
[0079]
<Image forming method>
The image forming method of the present invention comprises a charging means for charging a latent image carrier, a latent image forming means for exposing the charged latent image carrier to form an electrostatic latent image, and the electrostatic latent image Development means for developing using toner, transfer separation means for transferring the formed toner image to a recording material and separating it from a toner image holding member (latent image carrier), and the transferred toner image as a recording material In the image forming method of forming an image using an image forming apparatus having a fixing means for fixing on the image forming apparatus, the transfer separating means develops each color toner on a latent image carrier and transfers it to a transfer belt or a transfer drum. After that, the color image forming method is to transfer each color toner to a transfer body at once.
[0080]
When the above-described spherical toner is used, the packing property is inevitably improved at the conveyance restriction portion in the developing device, and accordingly, a strong force is applied not only to the toner surface but also to the carrier. Therefore, by containing a conductive material dispersed in the resin coating layer of the carrier, even if the resin coating layer is peeled off, it is possible to achieve high image quality over the long term without greatly changing the volume resistivity. I found out that I can.
[0081]
Any known intermediate transfer belt or intermediate transfer drum can be used.
[0082]
Another image forming method of the present invention uses an image forming apparatus in which a cleaning unit for removing toner remaining on a toner image holding member after transfer is provided between the transfer separating unit and the fixing unit. In the image forming method for forming an image, the cleaning unit is an image forming method for collecting residual toner on the latent image carrier using an electrostatic brush without rubbing the latent image carrier with a blade.
[0083]
Although it is generally used because of the high performance stability of the blade cleaning method, by using the toner of the present invention, it becomes possible to collect the residual toner on the latent image carrier using an electrostatic brush, The wear life of the latent image carrier can be greatly increased.
[0084]
In another image forming method of the present invention, an image is formed using an image forming apparatus that collects residual toner on the latent image carrier again in the developing machine without rubbing the latent image carrier with a blade. This is an image forming method.
[0085]
Further, by using the toner of the present invention, the cleaning system is not provided on the latent image carrier, and even when the residual toner is collected again in the developing device, the specific toner is not selectively accumulated and is stable. Development, transfer, and fixing performance can be obtained.
[0086]
Furthermore, another image forming method of the present invention includes a charging unit for charging the latent image carrier, a latent image forming unit for exposing the charged latent image carrier to form an electrostatic latent image, and the static image forming unit. Using an image forming apparatus having a developing unit that develops an electrostatic latent image with toner, and a transfer fixing separation unit that transfers the formed toner image onto a recording material, separates the toner image from a toner image holding member, and fixes the toner image simultaneously. In the image forming method for forming an image, the transfer / fixing / separating means develops each color toner on a latent image carrier, transfers the toner to a transfer belt, and then fixes each color to the transfer body at the same time as transferring the image. Is the method.
[0087]
In consideration of simultaneous transfer fixing, an intermediate transfer belt having a multilayer structure of a base layer and a surface layer can be used.
[0088]
For the base layer, a resin film containing a conductive filler such as carbon black or metal oxide can be used to control the resistance low. For the outermost surface layer, it is preferable to use a film made of a material having a low surface energy in order to improve the releasability of the toner. It is important that any material is a heat-resistant film, and PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer), PTFE (polytetrafluoroethylene), polyimide, silicone-based films, etc. may be used. it can. However, it is not limited to these.
[0089]
【Example】
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. In the description of the toner composition and the carrier, “part” means “part by weight” unless otherwise specified.
[0090]
In the production of the toner composition, the carrier, and the electrostatic latent image developer, each measurement was performed by the following method.
[0091]
<Measurement of volume average particle diameter of calcium compound particles>
The particles are embedded with a curable resin, sliced thinly with a diamond cutter, and observed with a TEM. The image was printed and 50 samples were arbitrarily extracted using the primary particles as samples, and the diameter of the circular particles corresponding to the image area was defined as the volume average particle size.
[0092]
<Electrical resistance measurement>
As shown in FIG. 1, the measurement sample 3 is sandwiched between the lower electrode 4 and the upper electrode 2 with a thickness H, the thickness is measured with a dial gauge while pressing from above, and the electrical resistance of the measurement sample 3 is measured with a high voltage ohmmeter. Measured with. Specifically, a specific titanium oxide sample is 500 kg / cm with a molding machine. ² A measurement disk was prepared by applying a pressure of. Next, the surface of the disk was cleaned with a brush, sandwiched between the upper electrode 2 and the lower electrode 4 in the cell, and the thickness was measured with a dial gauge. Next, voltage was applied and the current value of the electrometer 6 was read to determine the volume resistivity.
[0093]
Further, a carrier sample was filled in the lower electrode 4 of 100φ, the upper electrode 2 was set, a load of 3.43 kg was applied from above, and the thickness was measured with a dial gauge. Next, voltage was applied and the current value of the electrometer 6 was read to determine the volume resistivity.
[0094]
<Toner average shape index SF1>
In the present invention, the average shape index SF1 of the toner means a value calculated by the following formula, and SF1 = 100 in the case of a true sphere.
[Equation 3]
SF1 = (ML ² / A) × (π / 4) × 100
Here, ML is the absolute maximum length of the particles, and A is the projected area of the particles, and these are quantified mainly by analyzing a microscope image or an operation electron microscope image with an image analyzer.
[0095]
As a specific method for obtaining an average shape index, a toner image is taken from an optical microscope into an image analyzer (LUZEX III, manufactured by Nireco Corporation), an equivalent circle diameter is measured, and the maximum length and area are individually measured. The value of SF1 in the above formula is obtained for the particles of.
[0096]
<Charge amount measurement>
The charge amount at high temperature and high humidity and low temperature and low humidity is as follows: both toner assembly and carrier are left for 24 hours in high temperature and high humidity: 30 ° C., 90% RH, low temperature low humidity: 5 ° C., 10% RH, respectively. The toner composition and the carrier are collected in a glass bottle with a lid so that the TC is 5%, and tumbler stirring is performed in each atmosphere. The stirred developer is TB200 manufactured by Toshiba Corporation at 25 ° C. and 55% RH. Measured with Also, environmental difference (e) = charge amount under high temperature and high humidity / charge amount under low temperature and low humidity.
e ≧ 85%..., 80% ≦ e <85%..., e <80%.
[0097]
The charge amount in the actual machine evaluation test was measured with a TB200 manufactured by Toshiba under the conditions of 25 ° C. and 55% RH as described above, by collecting the developer on the mag sleeve in the developing device.
[0098]
[Preparation of hydrophobized calcium compound particles]
(A) Preparation of hydrophobized coated calcium carbonate particles
In a 2 liter stainless beaker, 1000 g of lime milk with a concentration of 6% by weight is blown with carbon dioxide gas with a concentration of 30% at a compounding start temperature of 17 ° C. at a rate of 0.3 L / min, and the conductivity of the suspension drops secondarily. Until it is stable. The reaction solution was suction filtered with a Nutsche, and the mother liquor was separated and dried and pulverized to obtain calcium carbonate particles.
[0099]
Next, a slurry of calcium carbonate particles having a solid content of 10% by weight was adjusted to 65 ° C. While stirring the slurry with a disperser, sodium erucate was added, stirred and then press dehydrated. The obtained filter cake was dried with a box dryer and then crushed to obtain surface-coated calcium carbonate particles having an average particle diameter of 50 nm and surface-coated with an organic acid.
[0100]
While dispersing the obtained calcium carbonate particles surface-coated with an organic acid by a dry disperser, 10 parts by weight of n-decyltrimethoxysilane was added dropwise with stirring in a nitrogen atmosphere, and the mixture was heated and stirred at 200 ° C. for 2 hours. After cooling, decylsilane / organic acid-coated calcium carbonate particles (A) having an average particle diameter of 50 nm were obtained. The weight ratio of decylsilane / sodium erucate was 16/1.
[0101]
(B) Preparation of hydrophobized coated calcium carbonate particles
Particles were produced in the same manner as in the above (A) to obtain calcium carbonate having an average particle diameter of 15 nm and surface-treated with an organic acid. While dispersing the obtained surface-coated calcium carbonate particles with a dry disperser, 10 parts by weight of n-decyltrimethoxysilane was added dropwise with stirring in a nitrogen atmosphere, and the mixture was heated and stirred at 200 ° C. for 2 hours. While further stirring, 20 parts by weight of dimethylpolysiloxane was added, kept at 250 ° C. for 30 minutes, and then cooled to obtain decylsilane / dimethylpolysiloxane / organic acid-coated calcium carbonate particles (B) having an average particle size of 15 nm. Obtained. The weight ratio of decylsilane / dimethylpolysiloxane / sodium erucate was 20/1.
[0102]
(C) Preparation of hydrophobized coated calcium carbonate particles
Particles were prepared in the same manner as in (A) above, and the surface treatment agent was changed from sodium erucate to a fatty acid mixture which is a mixture of sodium oleate, sodium stearate and sodium palmitate, and the average particle size was 30 nm. Thus, calcium carbonate surface-treated with an organic acid was obtained. While dispersing the obtained surface-coated calcium carbonate particles with a dry disperser, 10 parts by weight of dimethylpolysiloxane was added with stirring in a nitrogen atmosphere, and the mixture was heated and stirred at 200 ° C. for 2 hours. Dimethylpolysiloxane / organic acid-coated calcium carbonate particles (C) having a diameter of 30 nm were obtained. The weight ratio of dimethylpolysiloxane / fatty acid mixture was 4/1.
[0103]
(D) Preparation of hydrophobized coated hydroxyapatite particles
In a 2 L stainless beaker, 133 g of 42.5% phosphoric acid aqueous solution was gradually added to 710 g of 10% by weight lime milk at a compounding start temperature of 17 ° C. over about 30 minutes. Thereafter, the temperature of the reaction solution was raised to 80 ° C., and the mixture was heated and maintained for 24 hours while continuing to stir, and then aged. The reaction solution was suction filtered with a Nutsche to separate the mother liquor, followed by drying and pulverization to obtain hydroxyapatite particles.
[0104]
Next, a slurry of hydroxyapatite particles having a solid content of 10% by weight was adjusted to 65 ° C. While stirring the slurry with a disperser, sodium erucate was added, stirred and then press dehydrated. The obtained filter cake was dried with a box-type dryer and then crushed to obtain surface-coated hydroxyapatite particles having an average particle diameter of 50 nm and surface-coated with an organic acid.
[0105]
While dispersing the obtained surface-coated hydroxyapatite particles with a dry disperser, 10 parts by weight of dimethylpolysiloxane was added with stirring in a nitrogen atmosphere, heated and stirred at 200 ° C. for 2 hours, and then cooled to obtain an average particle size. Dimethylpolysiloxane / organic acid-coated hydroxyapatite particles (D) having a diameter of 50 nm were obtained. The weight ratio of dimethylpolysiloxane / sodium erucate was 4/1.
[0106]
(E) Preparation of hydrophobized coated calcium sulfoaluminate particles
In a 500 ml stainless beaker, 64 g of an 8% strength aqueous aluminum sulfate solution was added at a temperature of 50 ° C. to 68 g of 13% strength by weight lime milk. Thereafter, aging was carried out by further heating at 50 ° C. for 1 hour while continuing stirring. The reaction solution was suction filtered with a Nutsche, and the mother liquor was separated and dried and pulverized to obtain calcium sulfoaluminate particles.
[0107]
Next, a slurry of calcium sulfoaluminate particles having a solid content of 10% by weight was adjusted to 65 ° C. While stirring the slurry with a disperser, sodium erucate was added, stirred and then press dehydrated. The obtained filter cake was dried with a box dryer and then crushed to obtain surface-coated calcium sulfoaluminate particles having an average particle diameter of 50 nm and surface-coated with an organic acid.
[0108]
While dispersing the obtained surface-coated calcium sulfoaluminate particles with a dry disperser, adding 20 parts by weight of dimethylpolysiloxane while stirring in a nitrogen atmosphere, heating and stirring at 200 ° C. for 2 hours, and then cooling. Dimethylpolysiloxane / organic acid-coated calcium sulfoaluminate particles (E) having an average particle diameter of 50 nm were obtained. The weight ratio of dimethylpolysiloxane / sodium erucate was 20/1.
[0109]
(F) Adjustment of surface-treated calcium carbonate particles
Particles were produced in the same manner as in the above (A) to obtain calcium carbonate particles. Next, calcium carbonate particles are dispersed in water, a quaternary ammonium salt surfactant is added, ultrasonic waves are applied, water is distilled off by an evaporator, and heating is further performed at 110 ° C. for 1 hour, followed by pulverization. Then, surface treated calcium carbonate particles (F) having an average particle diameter of 50 nm were obtained.
[0110]
(G) Preparation of surface untreated calcium carbonate particles
In a 2 L stainless beaker, carbon dioxide gas having a concentration of 30% was blown at a compound start temperature of 17 ° C. at a rate of 0.3 L / min, and the reaction was continued until the conductivity of the suspension dropped to a stable value. The reaction solution was suction filtered with a Nutsche, and the mother liquor was separated and dried and pulverized to obtain untreated calcium carbonate particles (G) having an average particle size of 15 nm.
[0111]
[Method for producing colored particles]
(I) Colored particle A manufacturing method
100 parts by weight of styrene-n-butyl acrylate resin
(Tg = 58 ° C., Mn = 4000, Mw = 25000)
3 parts by weight of carbon black
(Mogal L: Cabot)
[0112]
The above mixture was kneaded with an extruder, pulverized with a jet mill, and then dispersed with a wind classifier to obtain a black toner A having a volume average particle diameter D50 = 5.0 μm and SF1 = 148.8.
[0113]
(Ii) Colored particle B manufacturing method
<Adjustment of resin dispersion (1)>
370 parts by weight of styrene
30 parts by weight of n-butyl acrylate
8 parts by weight of acrylic acid
24 parts by weight of dodecanethiol
4 parts by weight of carbon tetrabromide
[0114]
6 parts by weight of a nonionic surfactant (Nonipol 400: manufactured by Sanyo Kasei Co., Ltd.) and an anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) ) 10 parts by weight dissolved in 550 parts by weight of ion-exchanged water was emulsified and dispersed in a flask. While slowly mixing for 10 minutes, 50 parts by weight of ion-exchanged water in which 4 parts by weight of ammonium persulfate had been 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 (1) in which resin particles of 155 nm, Tg = 59 ° C., and weight average molecular weight Mw = 12000 were dispersed was obtained.
[0115]
<Adjustment of resin dispersion (2)>
280 parts by weight of styrene
120 parts by weight of n-butyl acrylate
8 parts by weight of acrylic acid
[0116]
6 parts by weight of a nonionic surfactant (Nonipol 400: manufactured by Sanyo Kasei Co., Ltd.) and an anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) ) 12 parts by weight dissolved in 550 parts by weight of ion-exchanged water was emulsified and dispersed in a flask. While slowly mixing for 10 minutes, 50 parts by weight of ion-exchanged water in which 3 parts by weight of ammonium persulfate had been dissolved was added. 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 of 105 nm, Tg = 53 ° C., and weight average molecular weight Mw = 550000 were dispersed was obtained.
[0117]
[Colorant dispersion]
<Preparation of colorant dispersion (1)>
50 parts by weight of carbon black
(Mogal L: Cabot)
Nonionic surfactant 5 parts by weight
(Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.)
200 parts by weight of ion exchange water
[0118]
The above components are mixed, dissolved, and dispersed for 10 minutes using a homogenizer (Ultra Turrax T50: manufactured by IKA). Colorant dispersion in which colorant (carbon black) particles having an average particle diameter of 250 nm are dispersed. Liquid (1) was prepared.
[0119]
<Preparation of colorant dispersion (2)>
Cyan pigment CIPigment Blue 15: 3 70 parts by weight
Nonionic surfactant 5 parts by weight
(Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.)
200 parts by weight of ion exchange water
[0120]
The above components are mixed, dissolved, and dispersed for 10 minutes using a homogenizer (Ultra Turrax T50: manufactured by IKA). Colorant dispersion in which colorant (Cyan pigment) particles having an average particle diameter of 250 nm are dispersed. Liquid (2) was prepared.
[0121]
<Preparation of colorant dispersion (3)>
Magenta pigment CIPigment Red122 70 parts by weight
Nonionic surfactant 5 parts by weight
(Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.)
200 parts by weight of ion exchange water
[0122]
The above components are mixed, dissolved, and dispersed for 10 minutes using a homogenizer (Ultra Turrax T50: manufactured by IKA). Colorant dispersion in which colorant (Magenta pigment) particles having an average particle diameter of 250 nm are dispersed. Liquid (3) was prepared.
[0123]
<Preparation of colorant dispersion (4)>
Yellow pigment CIPigment Yellow180 100 parts by weight
Nonionic surfactant 5 parts by weight
(Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.)
200 parts by weight of ion exchange water
[0124]
The above components are mixed, dissolved, and dispersed for 10 minutes using a homogenizer (Ultra Turrax T50: manufactured by IKA). Colorant dispersion in which colorant (Yellow pigment) particles having an average particle diameter of 250 nm are dispersed. Liquid (4) was prepared.
[0125]
[Preparation of release agent dispersion (1)]
50 parts by weight of paraffin wax
(HNP0190: Nippon Seiwa Co., Ltd., melting point 85 ° C.)
Cationic surfactant 5 parts by weight
(Sanisol B50: manufactured by Kao Corporation)
[0126]
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, and the average particle size was 550 nm. A release agent dispersion (1) in which the mold agent particles were dispersed was prepared.
[0127]
[Adjustment of aggregated particles]
Resin dispersion (1) 120 parts by weight
Resin dispersion (2) 80 parts by weight
Colorant dispersion (1) 200 parts by weight
Mold release dispersion (1) 40 parts by weight
Cationic surfactant 1.5 parts by weight
(Sanisol B50: manufactured by Kao Corporation)
[0128]
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 5.0 μm were formed. Further, 60 parts by weight of the resin dispersion liquid (1) as a resin-containing fine particle dispersion liquid was gradually added to the dispersion liquid. 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 a volume average particle diameter of about 5.6 μm were formed.
[0129]
[Creation of colored particles B]
After adding 3 parts by weight of an anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) to the dispersion of the aggregated particles, the stainless steel flask is sealed and stirred using a magnetic seal. Heat to 105 ° C. and hold for 4 hours. And after cooling, the reaction product was filtered, washed sufficiently with ion-exchanged water, and dried to obtain colored particles B for electrostatic image development.
[0130]
<Generation of colored particles KuroB>
Using the colorant dispersion (1), a Kuro toner having SF1 = 18.5 and particle size D50 = 5.8 μm was obtained by the above-described method of adjusting aggregated particles and preparing colored particles.
[0131]
<Generation of colored particles CyanB>
In the preparation of the aggregated particles, the colorant dispersion (2) is used in place of the colorant dispersion (1), and the Cyan toner having SF1 = 130 and particle size D50 = 5.6 μm is further prepared by the above-described method for producing the colored particles. Got.
[0132]
<Generation of colored particles Magenta B>
In the adjustment of the aggregated particles, the colorant dispersion liquid (3) is used instead of the colorant dispersion liquid (1). A Magenta toner was obtained.
[0133]
<Generation of colored particles YellowB>
In the adjustment of the aggregated particles, the colorant dispersion (4) is used instead of the colorant dispersion (1), and further, the yellow particles having SF1 = 127 and particle size D50 = 5.9 μm are prepared by the above-described method for preparing the colored particles. A toner was obtained.
[0134]
[Carrier generation]
Ferrite particles (average particle size: 50 μm) 100 parts by weight
14 parts by weight of toluene
2 parts by weight of styrene-methyl methacrylate copolymer
(Component ratio: 90/10)
Carbon black (R330: Cabot Corporation) 0.2 parts by weight
[0135]
First, the above components excluding ferrite particles are stirred with a stirrer for 10 minutes to prepare a dispersed coating solution. Next, the coating solution and ferrite particles are placed in a vacuum degassing kneader and stirred at 60 ° C. for 30 minutes. Then, the carrier was obtained by further depressurizing while depressurizing while heating and drying. This carrier has a volume resistivity of 10 at the time of an applied electric field of 1000 V / cm. ¹¹ It was Ωcm.
[0136]
Example 1
100 parts of each of the above colored particles B Kuro, Cyan, Magenta, Yellow, 0.7 parts of hydrophobized calcium carbonate particles (A), hydrophobic silica having an average particle diameter of 16 nm (R972, manufactured by Nippon Aerosil Co., Ltd.) 1.5 Part was blended for 10 minutes at a peripheral speed of 32 m / s using a Henschel mixer, and then coarse particles were removed using a sieve of 45 μm mesh to obtain a toner. 100 parts of the carrier and 5 parts of the toner were stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain a developer.
[0137]
(Example 2)
2 parts of calcium carbonate particles (B) and 1.4 parts of hydrophobic silica (RX50, manufactured by Nippon Aerosil Co., Ltd.) with an average particle diameter of 40 nm are added to 100 parts of the above colored particles KuroB, blended for 5 minutes at a peripheral speed of 20 m / s, 45 μm Coarse particles were removed using a mesh sieve to obtain a toner. 100 parts of the carrier and 5 parts of the toner were stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain a developer.
[0138]
(Example 3)
2 parts of calcium carbonate particles (C) and 1.5 parts of hydrophobic silica (R972, manufactured by Nippon Aerosil Co., Ltd.) having an average particle diameter of 16 nm are added to 100 parts of the above colored particles KuroB, blended at a peripheral speed of 20 m / s for 5 minutes, and 45 μm. Coarse particles were removed using a mesh sieve to obtain a toner. 100 parts of the carrier and 5 parts of the toner were stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain a developer.
[0139]
(Example 4)
2 parts of calcium carbonate particles (D) and 1.5 parts of hydrophobic silica (R972, manufactured by Nippon Aerosil Co., Ltd.) with an average particle diameter of 16 nm are added to 100 parts of the colored particles KuroB, blended for 5 minutes at a peripheral speed of 20 m / s, and 45 μm. Coarse particles were removed using a mesh sieve to obtain a toner. 100 parts of the carrier and 5 parts of the toner were stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain a developer.
[0140]
(Example 5)
2 parts of calcium carbonate particles (E) and 1.5 parts of hydrophobic silica (R972, manufactured by Nippon Aerosil Co., Ltd.) having an average particle diameter of 16 nm are added to 100 parts of the above colored particles KuroB, blended for 5 minutes at a peripheral speed of 20 m / s, and 45 μm. Coarse particles were removed using a mesh sieve to obtain a toner. 100 parts of the carrier and 5 parts of the toner were stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain a developer.
[0141]
(Comparative Example 1)
0.7 parts of hydrophobic titanium oxide (T805, manufactured by Nippon Aerosil Co., Ltd.) having an average particle diameter of 21 nm and 1.2 parts of hydrophobic silica (RX50, manufactured by Nippon Aerosil Co., Ltd.) having an average particle diameter of 40 nm are added to 100 parts of the colored particles KuroB. After blending for 10 minutes at a peripheral speed of 32 m / s using a Henschel mixer, coarse particles were removed using a sieve of 45 μm mesh to obtain a toner. A developer was obtained by stirring 100 parts of the carrier and 5 parts of the toner using a V-blender at 40 rpm for 20 minutes and sieving with a sieve having a 177 μm mesh.
[0142]
(Comparative Example 2)
1 part of untreated calcium carbonate particles (G) having an average particle diameter of 50 nm and 1.0 part of hydrophobic silica (R972, manufactured by Nippon Aerosil Co., Ltd.) having an average particle diameter of 16 nm are added to 100 parts of the colored particles KuroB using a Henschel mixer. After blending for 10 minutes at 32 m / s, coarse particles were removed using a sieve of 45 μm mesh to obtain a toner. 100 parts of the carrier and 5 parts of the toner were stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain a developer.
[0143]
(Comparative Example 3)
100 parts of the above colored particles KuroB, 0.3 parts of surface treated calcium carbonate particles (F), 1.5 parts of hydrophobic silica having an average particle diameter of 16 nm (R972, manufactured by Nippon Aerosil Co., Ltd.) using a Henschel mixer, a peripheral speed of 32 m / s After blending for 10 minutes, coarse particles were removed using a sieve of 45 μm mesh to obtain a toner. 100 parts of the carrier and 5 parts of the toner were stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain a developer.
[0144]
[Evaluation]
Using the developers described in the above examples and comparative examples, the charge amount and transferability were evaluated using a modified Docu Centra Color 500 manufactured by Fuji Xerox. The machine includes a charging means for charging the latent image carrier, a latent image forming means for exposing the charged latent image carrier to form an electrostatic latent image, and the electrostatic latent image with toner. A developing unit that develops the toner image, a transfer separation unit that transfers the formed toner image to a recording material and separates it from the latent image carrier, and a fixing unit that fixes the transferred toner image on the recording material. An image forming apparatus.
[0145]
The toner charge amount and the transfer efficiency are the results of the initial test, and the photosensitive member contamination and the photosensitive member scratches are the observation results of the photosensitive member after 100,000 copies.
[0146]
The transferability is evaluated by performing a hard stop at the end of the transfer process, transferring the toner weight on the two intermediate transfer members onto the tape in the same manner as described above, measuring the weight of the toner-attached tape, and averaging after subtracting the tape weight. Thus, the transfer toner amount a was obtained, and similarly, the toner amount b remaining on the photoreceptor was obtained, and the transfer efficiency was obtained by the following equation.
[Expression 4]
Transfer efficiency η (%) = a * 100 / (a + b)
And we made the following judgment.
η ≧ 99% ・ ・ ・ ○, 90% ≦ η <99% ・ ・ ・ △, η <90% ・ ・ ・ ×
[0147]
As shown in FIG. 2, toner flickering is performed by continuously flowing 50 solid images with a width of 50 mm and 270 mm with respect to the fixing nip entry direction on A4 paper, and then applying a character image to an area corresponding to the solid image portion. After forming and fixing, the line portion was subjected to sensory evaluation.
[0148]
The results are shown in Table 1.
[0149]
[Table 1]

[0150]
The developer using toner containing calcium compound particles subjected to hydrophobic surface treatment according to the present invention had good charging environment stability and good transferability as in the results of Examples 1-5. Further, when the photoconductor was taken out after copying 100,000 sheets and observed on the surface, scratches and contamination were slight.
[Table 2]

[0151]
On the other hand, the developer of the toner that does not contain calcium compound particles or does not satisfy the calcium carbonate that has not been subjected to the hydrophobic treatment has a slightly poor charging environment stability as in the results of Comparative Examples 1, 2, and 3, and further the image area. In particular, the image quality was insufficient due to flickering of the toner in the line image area. Further, when the photoconductor was taken out after copying 100,000 sheets and the surface was observed, in Comparative Example 1, scratches and toner contamination were remarkable. In Comparative Examples 2 and 3, toner contamination was remarkable.
[0152]
Further, Example 5 Kuro was examined by removing the cleaning blade of the above system, adding a brush, and changing the charging device to a roll charging device.
[0153]
As a result, a clear image was displayed as well as the initial image after copying 20,000 copies in the initial stage, and no image problem occurred.
[0154]
Further, Example 5 Kuro was examined using a scorotron charger without using any blade and brush cleaning in the above system.
[0155]
As a result, a clear image was displayed as well as the initial image after copying 20,000 copies in the initial stage, and no image problem occurred.
[0156]
【The invention's effect】
According to the electrostatic latent image developing toner, developer, and image forming method of the present invention, it is possible to obtain a remarkable effect of stably maintaining charging characteristics and transferability.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing the configuration of an apparatus for determining the volume resistivity of a carrier used in examples and comparative examples of the present invention.
FIG. 2 is a schematic diagram illustrating solid image formation during toner flicker evaluation.
[Explanation of symbols]
1 guard electrode, 2 upper electrode, 3 measurement sample, 4 lower electrode, 5 sample holding ring, 6 electrometer.

Claims (10)

In the dry toner for developing an electrostatic latent image containing at least a binder resin and a colorant, the surface of the toner is selected from the group consisting of at least sodium erucate, sodium oleate, sodium stearate, or sodium palmitate. A dry toner composition for developing an electrostatic latent image, comprising calcium compound particles hydrophobized with a coupling agent and / or silicone oil in addition to the organic acid metal salt .   2. The dry toner composition for developing an electrostatic latent image according to claim 1, wherein the calcium compound particles to be surface-treated are calcium carbonate, hydroxyapatite, or calcium sulfoaluminate.   The dry toner composition for developing an electrostatic latent image according to claim 1, wherein a primary particle diameter of the calcium compound particles is 0.005 to 0.07 μm.   The dry toner composition for developing an electrostatic latent image according to claim 1, wherein the coupling agent is n-decyltrimethoxysilane.   The dry toner composition for developing an electrostatic latent image according to claim 1, wherein the silicone oil is dimethylpolysiloxane. In the developer for developing an electrostatic latent image comprising a carrier and a toner composition, the carrier has a resin coating layer in which a conductive material is dispersed and contained in a matrix resin on a core material, and the toner composition is bound. Coupling in addition to at least one organic acid metal salt selected from the group consisting of sodium erucate, sodium oleate, sodium stearate, or sodium palmitate , containing at least a resin and a colorant on the surface of the toner composition A developer for developing an electrostatic latent image, which is a toner containing calcium compound particles hydrophobized with an agent and / or silicone oil. A charging means for charging the latent image carrier, a latent image forming means for exposing the charged latent image carrier to form an electrostatic latent image, and a developing means for developing the electrostatic latent image using toner. An image forming apparatus including: a transfer separation unit that transfers the formed toner image to a recording material and separates the toner image from the latent image carrier; and a fixing unit that fixes the transferred toner image on the recording material. In an image forming method for forming an image,
The toner has at least a binder resin and a colorant as components, and an organic acid metal selected from the group consisting of at least sodium erucate, sodium oleate, sodium stearate, or sodium palmitate on the surface of the toner Contains calcium compound particles that have been subjected to a hydrophobic treatment with a coupling agent and / or silicone oil in addition to a salt ,
A color image forming method, wherein the transfer separation unit develops each color toner on a latent image carrier, transfers the toner to a transfer belt or a transfer drum, and then transfers each color toner to the transfer body at once. A charging means for charging the latent image carrier, a latent image forming means for exposing the charged latent image carrier to form an electrostatic latent image, and a developing means for developing the electrostatic latent image using toner. A transfer separation unit that transfers the formed toner image to a recording material and separates it from a latent image carrier that is a toner image holding member, and a cleaning unit that removes toner remaining on the toner image holding member after transfer, In an image forming method for forming an image using an image forming apparatus having a fixing means for fixing a transferred toner image on a recording material,
The toner has at least a binder resin and a colorant as components, and an organic acid metal selected from the group consisting of at least sodium erucate, sodium oleate, sodium stearate, or sodium palmitate on the surface of the toner Contains calcium compound particles that have been subjected to a hydrophobic treatment with a coupling agent and / or silicone oil in addition to a salt ,
The image forming method, wherein the cleaning unit collects residual toner on the latent image carrier using an electrostatic brush without rubbing the latent image carrier with a blade. In an image forming method of forming an image using an image forming apparatus that collects residual toner on the latent image carrier again in the developing machine without rubbing the latent image carrier with a blade,
The toner has at least a binder resin and a colorant as components, and an organic acid metal selected from the group consisting of at least sodium erucate, sodium oleate, sodium stearate, or sodium palmitate on the surface of the toner An image forming method comprising calcium compound particles hydrophobized with a coupling agent and / or silicone oil in addition to a salt . A charging means for charging the latent image carrier, a latent image forming means for exposing the charged latent image carrier to form an electrostatic latent image, and a developing means for developing the electrostatic latent image using toner. And an image forming apparatus having an image forming apparatus that transfers the formed toner image to a recording material, and separates and fixes the toner image from the toner image holding member at the same time.
The toner has at least a binder resin and a colorant as components, and an organic acid metal selected from the group consisting of at least sodium erucate, sodium oleate, sodium stearate, or sodium palmitate on the surface of the toner Contains calcium compound particles that have been subjected to a hydrophobic treatment with a coupling agent and / or silicone oil in addition to a salt ,
A color image forming method, wherein the transfer fixing separation means develops each color toner on a latent image carrier, transfers the toner to a transfer belt, and then fixes each color to the transfer body at the same time as transferring.

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