JP2008076942A - Image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which is low in the torque of a cleaning blade while using an intermediate transfer member having at least a base material layer and a surface layer in the intermediate transfer member and containing a cured acrylic acid resin or a cured methacrylic acid resin as a main component at the surface layer, does not give rise to blade peeling and blade edge chipping, and obviates the occurrence of a cleaning defect even in the long term use, and an image forming method. <P>SOLUTION: The image forming apparatus primarily transfers the toner image formed by development on an electrophotographic photoreceptor to the intermediate transfer member, then secondarily transfers the toner image from the intermediate transfer member to a transfer material, in which the intermediate transfer member has at least a base material layer and a surface layer; the surface layer contains the cured acrylic acid resin or the cured methacrylic acid resin as the main component; and the toner contains a fatty acid metal salt. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming method and an image forming apparatus in which a toner image is secondarily transferred from an intermediate transfer member to a transfer material after primary transfer to the intermediate transfer member.

  In recent years, electrophotographic image forming apparatuses capable of copying and printing full-color images have been put into practical use. In particular, as a transfer method of a full-color image to a transfer material, a secondary transfer method using an intermediate transfer member is advantageous in that it can be used for many types of paper and can be copied on the entire surface. .

  The intermediate transfer body secondary transfer system is a method for sequentially printing yellow (Y), magenta (M), cyan (C), and black (Bk) color images sequentially formed on an electrostatic latent image carrier such as a photoreceptor. This is a system in which the images are sequentially superimposed and transferred onto an intermediate transfer body, and the transferred full-color toner images are collectively transferred to a transfer material, which is also called an intermediate transfer system (see, for example, Patent Documents 1 to 3).

  In such an intermediate transfer system, toner transferability is important, and there is a dropout phenomenon when the intermediate transfer body is peeled off from the surface of the photosensitive member, or a secondary transfer of the toner on the intermediate transfer body to paper or the like. This is a problem that the transferability is not sufficiently improved in a specific environment.

  In response to such problems, the present inventors particularly have an intermediate transfer member having at least a base layer and a surface layer, and the surface layer contains a cured acrylic resin or a cured methacrylic resin as a main component. It has been found that the intermediate transfer member solves the problem by optimizing its elastic characteristics and hardness due to its three-dimensional crosslinking, and can improve toner transfer properties (non-public literature, patent document 4: Japanese Patent Application No. 2006-125251). issue).

However, since these surface layer resins have a high affinity with the cleaning blade, the blade torque is particularly high under high-temperature and high-humidity conditions. I found it to be a problem.
JP 2002-132060 A JP 2004-117964 A JP 2005-266247 A Japanese Patent Application No. 2006-125251

  An object of the present invention is to solve the above problems. That is, an object of the present invention is to use an intermediate transfer member having at least a base layer and a surface layer, and containing a cured acrylic acid resin or a cured methacrylic acid resin as a main component in the surface layer. Image formation that has good transferability, low cleaning blade torque, stable transfer performance even when used for a long time, and does not cause blade failure or blade edge chipping. An apparatus and an image forming method are provided.

  As a result of intensive studies, the inventors added a lubricant such as zinc stearate to the toner, or applied it to the belt in the form of a rod, thereby reducing the slipperiness due to an increase in the coefficient of friction due to filming of the toner component. It can prevent blade mech and blade edge chipping. Accordingly, durability can be improved against the surface of the intermediate transfer member due to rubbing, the occurrence of scratches, and the like. These effects are achieved by the continuous supply of the slipperiness-imparting component to the surface, particularly by the means for imparting the slipperiness, particularly by the means for imparting slipperiness, and the stable and robust. It was found to have performance. Further, it was found that the lubricant can be more easily attracted by containing an inorganic oxide in the surface layer.

  That is, the object of the present invention is achieved by adopting the following configuration.

1.
In an image forming apparatus in which a toner image formed by development on an electrophotographic photosensitive member is primarily transferred to an intermediate transfer member, and then the toner image is secondarily transferred from the intermediate transfer member to a transfer material. It has at least a base material layer and a surface layer, and the surface layer contains a cured acrylic acid resin or a cured methacrylic acid resin as main components, and the toner contains a fatty acid metal salt. Image forming apparatus.

2.
In an image forming apparatus in which a toner image formed by development on an electrophotographic photosensitive member is primarily transferred to an intermediate transfer member, and then the toner image is secondarily transferred from the intermediate transfer member to a transfer material. It has at least a base material layer and a surface layer, and the surface layer contains a cured acrylic acid resin or a cured methacrylic acid resin as a main component, and has a mechanism for applying a fatty acid metal salt to the surface of the intermediate transfer member. An image forming apparatus.

3.
In an image forming apparatus in which a toner image formed by development on an electrophotographic photosensitive member is primarily transferred to an intermediate transfer member, and then the toner image is secondarily transferred from the intermediate transfer member to a transfer material. Having at least a base material layer and a surface layer, the surface layer containing a cured acrylic acid resin or a cured methacrylic acid resin as a main component, and a mechanism for applying a fatty acid metal salt to the surface of the electrophotographic photosensitive member An image forming apparatus comprising:

4).
The image forming apparatus according to any one of 1 to 3, wherein the fatty acid metal salt is selected from calcium stearate, aluminum stearate, and zinc stearate.

5.
The image forming apparatus according to any one of claims 1 to 4, wherein the surface layer contains a metal oxide.

6).
The image forming apparatus according to any one of claims 1 to 4, wherein the metal oxide is silica.

7).
7. An image forming method, which is used in the image forming apparatus according to any one of 1 to 6.

  In the present invention, “containing as a main component” means that it plays a main role in forming a coating film, and the content is not particularly limited. However, as a temporary guide, it can be said that it accounts for 50% by mass or more of the total mass of the forming layer (in this case, the surface layer).

  The reason why a remarkable effect can be obtained by the above-described configuration of the present invention is not particularly analyzed, but is estimated as follows. Since the affinity between the cured acrylic acid resin or cured methacrylic acid resin used for the surface layer and the fatty acid metal salt is very high, the surface of the intermediate transfer member exhibits a very good spreadability. Stable transferability will be obtained.

  According to the present invention, the intermediate transfer member has at least a base material layer and a surface layer, and the surface layer includes an intermediate transfer member containing a cured acrylic acid resin or a cured methacrylic acid resin as a main component. Therefore, it is possible to provide an image forming apparatus and an image forming method that do not cause a blade failure or chipping of a blade edge even when used for a long period of time and do not cause a cleaning failure.

  Next, the compound used in the present invention or the image forming method / apparatus will be further described.

[Layer structure of intermediate transfer member]
The layer structure of the intermediate transfer member of the present invention is preferably a structure having a surface layer on the substrate layer, and if necessary, the adhesion between the substrate layer and the surface layer is improved between the substrate layer and the surface layer. An intermediate layer may be provided for the purpose. FIG. 1 is a conceptual cross-sectional view showing an example of the layer structure of the intermediate transfer member.

  In FIG. 1, 70 is an intermediate transfer member, 701 is a base material layer, and 702 is a surface layer.

  The method for producing the intermediate transfer member of the present invention is preferably a method having a step of curing the surface layer by irradiating at least one of heat rays, actinic rays and electron beams.

  The thickness of the intermediate transfer member can be appropriately determined according to the purpose of use and the like, but in general, it is preferably 5 to 500 μm, more preferably 10 to 300 μm, which satisfies mechanical properties such as strength and flexibility, and 20 to 200 μm. Is more preferable.

  In the present invention, the surface means a surface onto which a toner image carried on the electrostatic latent image carrier is transferred.

  Next, the base material layer and surface layer composition of the intermediate transfer member of the present invention and the method for producing the intermediate transfer member will be described.

  Hereinafter, each layer constituting the intermediate transfer member will be described first.

[Base material layer]
The base material layer according to the present invention is not particularly limited and can be produced by a known forming method using a known material.

  The known material may be a metal, but preferably a resin material such as polycarbonate, polyphenylene sulfide, polyvinylidene fluoride, polyimide, polyether, polyether ketone, or a resin mainly composed of polyphenylene sulfide. .

  Examples of the forming method include a method in which a coating solution in which a resin is dissolved in a solvent is applied and a method in which the resin is directly formed, and a method in which the resin is directly formed is preferable.

  Examples of a method for forming a base material layer by directly forming a resin film include extrusion molding and inflation molding. In any case, the resin material and various conductive materials are melt-kneaded, and in the case of an extruder, the resin is extruded and cooled and molded, and in the case of the inflation method, the molten resin is formed into a cylinder in a mold, and a blower It can be produced by blowing air, cooling and forming into an endless belt shape.

  Hereinafter, a method for producing a base material layer using a resin containing polyphenylene sulfide as a main component by an extrusion molding method will be specifically described.

  The base material layer containing polyphenylene sulfide as a main component is formed of polyphenylene sulfide, a graft copolymer composed of an epoxy group-containing olefin copolymer and a vinyl (co) polymer, a conductive filler, and a lubricant.

  The polyphenylene sulfide (PPS) used in the present invention is a thermoplastic plastic having a structure in which phenylene units and sulfur atoms are alternately arranged.

  The phenylene unit is an o-phenylene unit, m-phenylene unit or p-phenylene unit which may have a substituent, and these may be mixed. Preferred phenylene units include at least p-phenylene units, and the content thereof is 50% or more based on the total phenylene units. The phenylene unit is particularly preferably composed of only an unsubstituted p-phenylene unit.

  Carbon black can be used as the conductive filler used in the present invention. As the carbon black, neutral carbon black can be used. The amount of the conductive filler used varies depending on the type of the conductive filler to be used, but it may be added so that the volume resistance value and the surface resistance value of the intermediate transfer member are in a predetermined range. Usually, 100 parts by mass of polyphenylene sulfide is used. It is 10-20 mass parts with respect to this, Preferably it is 10-16 mass parts.

  The lubricant used in the present invention improves molding processability to an intermediate transfer member, and includes, for example, aliphatic hydrocarbons such as paraffin wax and polyolefin wax, lauric acid, myristic acid, palmitic acid, stearin Higher fatty acids such as acids and behenic acid, higher fatty acid metal salts such as sodium salts, lithium salts and calcium salts of the higher fatty acids. These lubricants may be used alone or in combination of two or more. The amount of the lubricant used is 0.1 to 0.5 parts by mass, preferably 0.1 to 0.3 parts by mass with respect to 100 parts by mass of polyphenylene sulfide.

  The base material layer according to the present invention has an annular die attached to a single screw extruder, a mixture made of the above-mentioned materials is charged into the extruder, and a molten resin composition is fed from a seamless belt-shaped resin discharge port at the tip of the annular die. The resin can be solidified by extrusion and then extrapolated into a cooling cylinder having a cooling mechanism, and can be easily formed into a seamless cylindrical shape.

  At this time, as a device not causing crystallization, it is preferable to perform cooling with water, air, a cooled metal block or the like immediately after the belt is discharged from the mold. Specifically, a cooling cylinder provided with a heat insulating material sandwiched between molds is used, thereby rapidly depriving the belt of heat. Water whose temperature is adjusted to 30 ° C. or lower is circulated constantly inside the cooling cylinder. Further, the belt discharged from the mold may be taken up at high speed to reduce the film thickness and increase the cooling rate. In this case, the take-up speed is preferably 1 m / min or more, particularly preferably 2 to 7 m / min.

  When the ratio D / d between the diameter D of the annular die and the diameter d of the cooling cylinder is 0.9 to 1.1, the resin extruded from the annular die to the cooling cylinder is taken out by the take-out device while being externally inserted. At that time, when D / d is 0.9 to 0.98, it is necessary to evacuate between the annular die and the cooling cylinder in order to run the resin along the cooling cylinder. However, when D / d is 0.99 to 1.02, the resin can run along the cooling cylinder without evacuating the annular cylinder from the cooling cylinder, and pulsation due to evacuation occurs. In addition, there is an advantage that film thickness fluctuation in the take-off direction hardly occurs.

  In addition, as a resin for base material layers, for example, a polyimide resin can be used in the same manner as described above.

[Surface layer]
As the resin for the surface layer according to the present invention, a cured acrylic acid resin or a cured methacrylic acid resin is used as the main component.

  The surface layer of the cured (meth) acrylic resin can be obtained, for example, by irradiating with ultraviolet rays after forming a coating layer containing a (meth) acrylic acid monomer or oligomer and a polymerization initiator. Of course, you may use active rays other than ultraviolet rays, such as an X-ray and an electron beam.

The cured acrylic acid monomer or oligomer is a compound having a plurality of acryloyloxy groups (CH ₂ ═CHCOO—) or methacryloyloxy groups (CH ₂ ═C (CH ₃ ) COO—).

  If the example of a typical compound is given, the thing of the following structure can be mentioned.

  Examples of the polymerization initiator for the ultraviolet curable resin include benzophenone, Michler ketone, 1-hydroxycyclohexyl-phenyl ketone, thioxanthone, benzobutyl ether, acyloxime ester, dibenzothroben, bisacylphosphine oxide and the like.

  The surface layer can be formed by adding an additive such as a conductive material, a resistance adjusting agent such as an inorganic filler, if necessary.

  The characteristics of the surface layer are affected by the type of ultraviolet curable acrylic monomer or oligomer, its composition ratio, ultraviolet curing conditions, and the like.

  That is, the surface layer of the intermediate transfer member is preferably a resin prepared by reacting a monomer having a bifunctional or higher functional group with a cured (meth) acrylic resin to be formed. Resin formed by reacting monomers, and made of cured (meth) acrylic acid having an alkyl group with 12 or more carbon atoms, or contains resin that reacts with bifunctional oligomer as main components To exhibit particularly good characteristics.

  This is because an increase in surface hardness is preferable for improving transferability, and a large number of functional groups is preferable for increasing the surface hardness. If it is bifunctional or higher, it becomes a cross-linked film, and the surface hardness is preferably increased. A more preferable mode for realizing high transfer quality is to use a high cross-linking density type raw material having 5 or more functional groups. However, since increasing the hardness also increases the possibility that the film becomes brittle and easily breaks, it is preferable that the molecule has a structure with a long molecular chain. In the case of hydrocarbons, by curing a compound having an alkyl chain with 12 or more carbon atoms, it is possible to obtain a surface layer having microscopic hardness that can improve transferability and macro-flexibility that is resistant to cracking. It is done.

  Examples of the polymerization initiator for the ultraviolet curable resin include benzophenone, Michler ketone, 1-hydroxycyclohexyl-phenyl ketone, thioxanthone, benzobutyl ether, acyloxime ester, dibenzothroben, bisacylphosphine oxide and the like.

  As a method of providing the surface layer on the base material layer, the surface layer coating solution is spray-coated on the base material layer to form a coating film, and after the primary drying until the fluidity of the coating film is lost, A method is preferred in which the ultraviolet curable resin is cured by irradiating ultraviolet rays, and further, secondary drying is performed to make the amount of volatile substances in the coating film a specified amount.

  The spray coating solution is prepared by mixing an ultraviolet curable acrylic acid monomer or oligomer, a polymerization initiator, a diluting solvent, and a conductive material, an inorganic filler, a resistance adjusting agent, etc., if necessary, and then dispersing it using a sand mill or a stirring device. be able to.

  The dilution solvent is not particularly limited as long as it dissolves the ultraviolet curable acrylic monomer or oligomer and the polymerization initiator, and specifically, n-butyl alcohol, isopropyl alcohol, ethyl alcohol, methyl alcohol, methyl isobutyl ketone, And methyl ethyl ketone.

  As a device for irradiating ultraviolet rays, a known device used for curing an ultraviolet curable resin can be used.

The amount of ultraviolet rays (mJ / cm ² ) for curing the resin with ultraviolet rays is preferably controlled by the ultraviolet irradiation intensity and the irradiation time.

[Resistance adjuster]
As described above, it is preferable to add a resistance adjusting agent to the base material layer and the surface layer as necessary. Examples of the resistance adjusting agent include conductive substance particles and various fillers.

  Examples of the conductive particles include metals, metal oxides, conductive polymers, and carbon black. Examples of the metal include aluminum, zinc, copper, chromium, nickel, stainless steel, silver, and the like, and those obtained by depositing these metals on the surface of plastic particles. Examples of the metal oxide include zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin oxide doped with antimony, and zirconium oxide. In addition, examples of the conductive polymer include polyacetylene, polythiophene, and polypyrrole.

[Other additives]
In addition to the above, additives can be added to the surface layer.

  For example, fluorine particles, silica particles, acrylic particles, melamine particles, and the like that impart surface layer releasability may be added. Of these, the addition of silica particles is particularly preferable because the film hardness increases and transferability is improved. Further, it is preferable to add tetrafluoroethylene particles as fluorine particles because cleaning properties are enhanced.

[Image Forming Method, Image Forming Apparatus]
Next, an image forming method and an image forming apparatus according to the present invention will be described.

  The image forming apparatus has an electrostatic latent image bearing member (typically an electrophotographic photosensitive member, hereinafter sometimes simply referred to as a photosensitive member), and developing with a developer including a charging unit, an exposing unit, and a small-diameter toner. And a transfer means for transferring the toner image formed by the developing means to a transfer material via an intermediate transfer member.

  In particular, the present invention is characterized by 1) an image forming apparatus having a mechanism for applying a fatty acid metal salt to the surface of the electrophotographic photosensitive member, and 2) having a mechanism for applying a fatty acid metal salt to the surface of the intermediate transfer member. And 3) an image forming apparatus characterized in that the toner contains a fatty acid metal salt.

[Fatty acid metal salt]
In general, the fatty acid metal salt is preferably a metal salt of a saturated or unsaturated fatty acid having 10 or more carbon atoms. Examples include aluminum stearate, indium stearate, gallium stearate, zinc stearate, lithium stearate, magnesium stearate, sodium stearate, aluminum palmitate, aluminum oleate, and the like, more preferably metal stearate. .

In the present invention, among fatty acid metal salts, a fatty acid metal salt having a high flow tester flow rate is particularly high in cleavage, and the fatty acid metal salt layer can be more effectively formed on the surface of the intermediate transfer member of the present invention. The range of the outflow rate is preferably 1 × 10 ⁻⁷ ml / sec or more and 1 × 10 ⁻¹ ml / sec or less, and most preferably 5 × 10 ⁻⁴ ml / sec or more and 1 × 10 ⁻² ml / sec or less. . The flow rate of the flow tester was measured using a Shimadzu flow tester “CFT-500” (manufactured by Shimadzu Corporation). A particularly preferred fatty acid metal salt falling within this range is zinc stearate.

When the fatty acid metal salt is contained in the developer, the fatty acid metal salt is preferably mixed and dispersed in the toner in the toner post-processing step. The addition amount depends on the particle size of the toner, but 0.01 to 1% by mass is preferable for a general toner volume median diameter (D ₅₀ ) of 2.5 to 7.0 μm. If the fatty acid metal salt is less than 0.01% by mass, the transition from the toner surface to the intermediate transfer member surface becomes insufficient, and it is difficult to form a thin film on the intermediate transfer member surface. On the other hand, when the content is more than 1% by mass, the adhesion of the paper powder to the fatty acid metal salt thin film formed on the surface of the intermediate transfer member increases, and image blur tends to occur.

  In addition, it is preferable to add inorganic fine particles and organic fine particles to the surface layer of the intermediate transfer member. In this case, the use of inorganic fine particles is particularly preferred, the use of inorganic oxide particles such as silica is preferred, and these inorganic fine particles are preferably hydrophobized with a silane coupling agent or a titanium coupling agent.

Further, the fatty acid metal salt can be supplied to the surface of the intermediate transfer member via a cleaning auxiliary member or the like. The amount of the fatty acid metal salt on the surface layer is preferably 0.1 to 10 mg / m ² . If the fatty acid metal salt is 0.01 mg / m ² , a sufficient effect cannot be obtained. ^{On the other hand} , when the amount is more than 10 mg / m ^2, the adhesion of paper dust to the surface of the photoreceptor increases and image blurring is likely to occur.

  Specific examples of usage of the present invention include a copying machine and a laser printer. In particular, an image forming apparatus capable of continuous printing of 5000 sheets or more is preferable. In such an apparatus, since a large amount of prints can be produced in a short time, a trouble related to the transfer is likely to occur, and particularly preferable results can be obtained by using the intermediate transfer member of the present invention which can obtain a stable secondary transfer.

  An image forming apparatus capable of using the intermediate transfer member of the present invention includes a photosensitive member that forms an electrostatic latent image according to image information, a developing device that develops the electrostatic latent image formed on the photosensitive member, and a photosensitive member. A primary transfer unit that transfers the toner image on the intermediate transfer member; a secondary transfer unit that transfers the toner image on the intermediate transfer member onto a transfer material such as paper or an OHP sheet; In addition, by having the intermediate transfer member of the present invention as an intermediate transfer member, stable toner image formation can be performed without causing transfer failure during secondary transfer.

  As an example of a method of applying a lubricant to a photoreceptor that can be used in the present invention, a case where a fatty acid metal salt is supplied to the surface of the photoreceptor via a cleaning auxiliary member will be described.

  FIG. 2 shows a cross-sectional view of an example in which a fatty acid metal salt solid member is used as a flicker for a brush roller.

  In FIG. 2, the brush roller 4 is brought into contact with the photoconductor on the cleaning blade 6 and the downstream side (with respect to the photoconductor rotation direction). A solid material of fatty acid metal salt is used for the flicker 3 for scraping off the toner of the brush, and the fatty acid metal salt can be supplied from the flicker to the surface of the photoreceptor through a brush roller. In the figure, reference numeral 1 denotes a photosensitive member, 2 denotes a cylindrical brush support, 5 denotes a brush roller positioning member, and 7 denotes a cleaning blade positioning member. As another method, a fatty acid metal salt may be soaked in the stitches of the woven fabric and contacted with the surface of the photoreceptor as a web roller instead of the brush roller of FIG.

  The application mechanism of the intermediate transfer belt can be applied by the same mechanism except that the photosensitive member is replaced with a belt.

  The application amount of the fatty acid metal salt can be achieved, for example, by appropriately controlling the number of rotations of the brush, the pressure applied to the brush application target (photosensitive member, intermediate transfer belt), and the rotation direction of the application target and the brush. The thickness of the fiber of the brush is preferably in the range of 10 to 50 denier (mass (g) of 9,000 m yarn), and the biting amount α with respect to the photoreceptor or intermediate transfer belt is in the range of 0.4 to 1.5 mm. Preferably there is. The biting amount α was defined as the maximum value at which the tip of the brush fiber entered the photosensitive drum when the photosensitive drum 1 did not exist.

  As an image forming apparatus that can use the intermediate transfer member of the present invention, it can also be used in a monochrome image forming apparatus that forms an image with a single color toner. However, it is more suitable for use in color image forming apparatuses that sequentially transfer toner images on a photoreceptor to an intermediate transfer body, tandem color image forming apparatuses in which a plurality of photosensitive bodies for each color are arranged in series on an intermediate transfer body, and the like. preferable.

  The intermediate transfer member of the present invention is particularly effective when used for tandem color image formation, and FIG. 2 is a sectional view showing an example of an image forming apparatus in which the intermediate transfer member of the present invention can be used.

  In FIG. 2, 1Y, 1M, 1C and 1K are photosensitive members, 4Y, 4M, 4C and 4K are developing means, 5Y, 5M, 5C and 5K are primary transfer rollers as primary transfer means, and 5A is a secondary transfer roller. Secondary transfer rollers as means, 6Y, 6M, 6C and 6K are cleaning means, 7 is an intermediate transfer member unit, 24 is a heat roll type fixing device, and 70 is an intermediate transfer member.

  This image forming apparatus is called a tandem type color image forming apparatus. The main structure of the image forming apparatus is a plurality of image forming units 10Y, 10M, 10C, and 10K, and an endless belt-shaped intermediate transfer belt as a transfer unit. Intermediate transfer body unit 7, sheet feeding and conveying means 22 </ b> A to 22 </ b> D for conveying recording member P, and heat roll type fixing device 24 as a fixing means. A document image reading device SC is disposed on the upper part of the main body A of the image forming apparatus.

  As one of the different color toner images formed on each photoconductor, an image forming unit 10Y that forms a yellow image includes a drum-shaped photoconductor 1Y as a first photoconductor, and a periphery of the photoconductor 1Y. A charging unit 2Y, an exposure unit 3Y, a developing unit 4Y, a primary transfer roller 5Y as a primary transfer unit, and a cleaning unit 6Y. An image forming unit 10M that forms a magenta image as another different color toner image is disposed around a drum-shaped photoconductor 1M as a first photoconductor, and the photoconductor 1M. A charging unit 2M, an exposure unit 3M, a developing unit 4M, a primary transfer roller 5M as a primary transfer unit, and a cleaning unit 6M. In addition, an image forming unit 10C that forms a cyan image as one of other different color toner images is disposed around the photoconductor 1C as a drum-type photoconductor 1C as a first photoconductor. The charging unit 2C, the exposure unit 3C, the developing unit 4C, a primary transfer roller 5C as a primary transfer unit, and a cleaning unit 6C are provided. Further, an image forming unit 10K that forms a black image as one of other different color toner images is disposed around a drum-shaped photosensitive member 1K as a first photosensitive member, and the photosensitive member 1K. It has a charging unit 2K, an exposure unit 3K, a developing unit 4K, a primary transfer roller 5K as a primary transfer unit, and a cleaning unit 6K.

  The endless belt-shaped intermediate transfer body unit 7 includes an intermediate transfer body 70 as a second image carrier having an intermediate transfer endless belt shape that is wound around a plurality of rollers and is rotatably supported.

  Each color image formed by the image forming units 10Y, 10M, 10C, and 10K is sequentially transferred onto the rotating endless belt-shaped intermediate transfer body 70 by the primary transfer rollers 5Y, 5M, 5C, and 5K, and is combined. A colored image is formed. A recording member P such as a sheet as a transfer material accommodated in the sheet feeding cassette 20 is fed by the sheet feeding / conveying means 21, passes through a plurality of intermediate rollers 22 A, 22 B, 22 C, 22 D, and a registration roller 23, and is secondary. A color image is transferred onto the recording member P at a time by being conveyed to a secondary transfer roller 5A as a transfer means. The recording member P to which the color image has been transferred is fixed by a heat roll type fixing device 24, is sandwiched between paper discharge rollers 25, and is placed on a paper discharge tray 26 outside the apparatus.

  On the other hand, after the color image is transferred to the recording member P by the secondary transfer roller 5A, the residual toner is removed by the cleaning unit 6A from the intermediate transfer body 70 from which the recording member P is separated by curvature.

  The secondary transfer roller 5A comes into pressure contact with the intermediate transfer member 70 only when the recording member P passes through the secondary transfer roller 5A and secondary transfer is performed.

  The housing 8 can be pulled out from the apparatus main body A through the support rails 82L and 82R. The housing 8 includes the image forming units 10Y, 10M, 10C, and 10K, the endless belt-shaped intermediate transfer body unit 7, and the like. Have

  The image forming units 10Y, 10M, 10C, and 10K are arranged in tandem in the vertical direction. An endless belt-shaped intermediate transfer body unit 7 is arranged on the left side of the photoreceptors 1Y, 1M, 1C, and 1K in the figure. The intermediate transfer member unit 7 includes an endless belt-like intermediate transfer member 70 that can be rotated by winding rollers 71, 72, 73, 74, and 76, a primary transfer roller 5Y, 5M, 5C, and 5K, and a cleaning unit 6A. Become.

  In actual image formation, toner images are formed on the photoreceptors 1Y, 1M, 1C, and 1K by charging, exposure, and development, and the toner images of the respective colors are superimposed on the endless belt-shaped intermediate transfer body 70, and collectively. The image is transferred to the recording member P, and is fixed by pressing and heating with a heat roll type fixing device 24. After the toner image is transferred to the recording member P, the intermediate transfer body 70 cleans the toner remaining on the intermediate transfer body at the time of transfer by the cleaning device 6A, and then enters the above-described charging, exposure, and development cycle. Image formation is performed.

[Recording member]
The recording member (recording paper) used in the present invention is a support for holding a toner image, and is usually called an image support, a transfer material or a transfer paper. Specific examples include various kinds of transfer materials such as plain paper from thin paper to thick paper, coated printing paper such as art paper and coated paper, commercially available Japanese paper and postcard paper, plastic films for OHP, and cloth. However, it is not limited to these.

[Developer used in the present invention]
The developer for forming a toner image of the present invention is not particularly limited as long as it is used for dry development. Since the developing method is not particularly limited, either a two-component developer composed of a carrier and a toner or a one-component developer composed of only a toner may be used. However, in the case of using a one-component developer, it is needless to say that a non-magnetic one-component developing toner using a non-magnetic toner that does not contain a magnetic material other than black toner (Bk toner) is preferable.

  As the binder resin constituting the toner, known resins such as styrene-acrylic resin and polyester resin can be used. The method for producing the toner may be either a pulverization method or a polymerization method, but a toner produced by the polymerization method is preferred.

The toner preferably has a volume median diameter (D ₅₀ ) of about 2.5 to 7.0 μm.

  In the case where the fatty acid metal edge is added to the developer, a fatty acid metal salt is added to the toner as described below. As a method for adding to the toner, for example, it is added when an external additive described below is added.

(Monomer)
As the polymerizable monomer to be used, a radical polymerizable monomer is an essential component, and a crosslinking agent can be used as necessary. Moreover, it is preferable to contain at least one radical polymerizable monomer having the following acidic group or radical polymerizable monomer having a basic group.

(1) Radical polymerizable monomer The radical polymerizable monomer component is not particularly limited, and a conventionally known radical polymerizable monomer can be used. Moreover, it can be used combining 1 type (s) or 2 or more types so that the required characteristic may be satisfy | filled.

  Specifically, aromatic vinyl monomers, (meth) acrylic acid ester monomers, vinyl ester monomers, vinyl ether monomers, monoolefin monomers, diolefin monomers , Halogenated olefin monomers and the like can be used.

  Examples of the aromatic vinyl monomer include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, p-methoxy styrene, p-phenyl styrene, p-chloro styrene, p-ethyl styrene, p. -N-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, 2, Examples thereof include styrene monomers such as 4-dimethylstyrene and 3,4-dichlorostyrene and derivatives thereof.

  Examples of (meth) acrylic acid ester monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, and methacrylic acid. Examples include butyl, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like.

  Examples of vinyl ester monomers include vinyl acetate, vinyl propionate, and vinyl benzoate.

  Examples of the vinyl ether monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether and the like.

  Examples of the monoolefin monomer include ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-1-pentene and the like.

  Examples of the diolefin monomer include butadiene, isoprene, chloroprene and the like.

  Examples of the halogenated olefin monomer include vinyl chloride, vinylidene chloride, vinyl bromide and the like.

(2) Crosslinking agent As the crosslinking agent, a radical polymerizable crosslinking agent may be added to improve the properties of the toner. Examples of the radically polymerizable crosslinking agent include those having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and diallyl phthalate.

(3) Radical polymerizable monomer having an acidic group or radical polymerizable monomer having a basic group As the radical polymerizable monomer having an acidic group or the radical polymerizable monomer having a basic group, For example, amine-based compounds such as carboxyl group-containing monomers, sulfonic acid group-containing monomers, primary amines, secondary amines, tertiary amines, and quaternary ammonium salts can be used.

  Examples of the radical polymerizable monomer having an acidic group include carboxylic acid group-containing monomers such as acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, maleic acid monobutyl ester, and maleic acid monoester. An octyl ester etc. are mentioned.

  Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfosuccinic acid, octyl allyl sulfosuccinate and the like.

  These may have a structure of an alkali metal salt such as sodium or potassium or an alkaline earth metal salt such as calcium.

  Examples of the radical polymerizable monomer having a basic group include amine compounds, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and quaternary ammonium salts of the above four compounds, 3-dimethylaminophenyl acrylate, 2-hydroxy-3-methacryloxypropyltrimethylammonium salt, acrylamide, N-butylacrylamide, N, N-dibutylacrylamide, piperidylacrylamide, methacrylamide, N-butylmethacrylamide, N-octadecylacrylamide Vinyl pyridine, vinyl pyrrolidone; vinyl-N-methylpyridinium chloride, vinyl-N-ethylpyridinium chloride, N, N-di Lil ammonium chloride, N, may be mentioned N- diallyl-ethyl chloride or the like.

  As the radically polymerizable monomer used in the present invention, a radically polymerizable monomer having an acidic group or a radically polymerizable monomer having a basic group is used in an amount of 0.1 to 15% by weight based on the whole monomer. The radical polymerizable crosslinking agent is preferably used in the range of 0.1 to 10% by mass with respect to the total radical polymerizable monomer, although it depends on its properties.

(Chain transfer agent)
For the purpose of adjusting the molecular weight, it is possible to use a commonly used chain transfer agent.

  The chain transfer agent is not particularly limited, and for example, octyl mercaptan, dodecyl mercaptan, tert-dodecyl mercaptan, n-octyl-3-mercaptopropionic acid ester, carbon tetrabromide and styrene dimer are used.

(Polymerization initiator)
The radical polymerization initiator used in the present invention can be appropriately used as long as it is water-soluble. For example, persulfate (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4′-azobis-4-cyanovaleric acid and its salts, 2,2′-azobis (2-amidinopropane) salt, etc.), A peroxide compound etc. are mentioned.

  Furthermore, the radical polymerization initiator can be combined with a reducing agent as necessary to form a redox initiator. By using a redox initiator, the polymerization activity is increased, the polymerization temperature can be lowered, and the polymerization time can be further shortened.

  The polymerization temperature may be any temperature as long as it is equal to or higher than the lowest radical generation temperature of the polymerization initiator. For example, a range of 50 ° C. to 90 ° C. is used. However, it is also possible to polymerize at room temperature or slightly higher temperature by using a polymerization initiator that starts at room temperature, for example, a combination of hydrogen peroxide and a reducing agent (ascorbic acid or the like).

(Surfactant)
In order to perform polymerization using the above-mentioned radical polymerizable monomer, it is necessary to perform oil droplet dispersion in an aqueous medium using a surfactant. Although it does not specifically limit as surfactant which can be used in this case, The following ionic surfactant can be mentioned as an example of a suitable thing.

  Examples of ionic surfactants include sulfonates (sodium dodecylbenzenesulfonate, sodium arylalkylpolyethersulfonate, 3,3-disulfonediphenylurea-4,4-diazo-bis-amino-8-naphthol-6 Sodium sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-6-sodium sulfonate, etc.), sulfuric acid Ester salts (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc.), fatty acid salts (sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate) Beam, calcium oleate and the like).

  Nonionic surfactants can also be used. Specifically, polyethylene oxide, polypropylene oxide, combination of polypropylene oxide and polyethylene oxide, ester of polyethylene glycol and higher fatty acid, alkylphenol polyethylene oxide, ester of higher fatty acid and polyethylene glycol, ester of higher fatty acid and polypropylene oxide, sorbitan ester Etc.

  In the present invention, these are mainly used as an emulsifier at the time of emulsion polymerization, but may be used for other processes or purposes.

(Coloring agent)
Examples of the colorant include inorganic pigments, organic pigments, and dyes.

  A conventionally well-known thing can be used as an inorganic pigment. Specific inorganic pigments are exemplified below.

  Examples of the black pigment include carbon black such as furnace black, channel black, acetylene black, thermal black, and lamp black, and magnetic powder such as magnetite and ferrite.

  These inorganic pigments can be used alone or in combination as required. Moreover, the addition amount of a pigment is 2-20 mass% with respect to a polymer, Preferably 3-15 mass% is selected.

  Conventionally known organic pigments and dyes can also be used. Specific organic pigments and dyes are exemplified below.

  Examples of pigments for magenta or red include C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. And CI Pigment Red 222.

  Examples of the orange or yellow pigment include C.I. I. Pigment orange 31, C.I. I. Pigment orange 43, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 138, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 185, C.I. I. Pigment yellow 155, C.I. I. Pigment yellow 156, and the like.

  Examples of pigments for green or cyan include C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 16, C.I. I. Pigment blue 60, C.I. I. And CI Pigment Green 7.

  As the dye, C.I. I. Solvent Red 1, C.I. I. Solvent Red 49, C.I. I. Solvent Red 52, C.I. I. Solvent Red 58, C.I. I. Solvent Red 63, C.I. I. Solvent Red 111, C.I. I. Solvent Red 122, C.I. I. Solvent Yellow 19, C.I. I. Solvent Yellow 44, C.I. I. Solvent Yellow 77, C.I. I. Solvent Yellow 79, C.I. I. Solvent Yellow 81, C.I. I. Solvent Yellow 82, C.I. I. Solvent Yellow 93, C.I. I. Solvent Yellow 98, C.I. I. Solvent Yellow 103, C.I. I. Solvent Yellow 104, C.I. I. Solvent Yellow 112, C.I. I. Solvent Yellow 162, C.I. I. Solvent Blue 25, C.I. I. Solvent Blue 36, C.I. I. Solvent Blue 60, C.I. I. Solvent Blue 70, C.I. I. Solvent Blue 93, C.I. I. Solvent blue 95 etc. can be used and these mixtures can also be used.

  These organic pigments and dyes can be used alone or in combination as desired. Moreover, the addition amount of a pigment is 2-20 mass% with respect to a polymer, Preferably 3-15 mass% is selected.

(Release agent)
A release agent may be contained in the toner of the present invention. There is no particular limitation on the structure and composition of the release agent itself. Low molecular weight polyolefin waxes such as polypropylene and polyethylene, paraffin wax, Fischer-Tropsch wax, ester wax and the like can be used.

  The addition amount is 1 to 30% by mass, preferably 2 to 20% by mass, and more preferably 3 to 15% by mass with respect to the whole toner.

  The toner of the present invention is obtained by dispersing a polymer in which a release agent is dissolved in a monomer and dispersing it in water to form particles in which an ester compound is encapsulated in resin particles, and salting out together with the colorant particles. / It is preferable to make the toner by fusing.

(Manufacturing process)
The toner of the present invention includes a step of dispersing a monomer solution in which a release agent is dissolved in an aqueous medium, and then preparing resin particles containing the release agent by a polymerization method, and an aqueous system using the resin particle dispersion. The step of fusing the resin particles in the medium, the washing step of filtering the obtained particles from the aqueous medium to remove the surfactant, the step of drying the obtained particles, and the particles obtained by further drying It is preferable to produce by a polymerization method comprising an external additive addition step of adding an external additive or the like. Here, the resin particles may be colored particles. Further, non-colored particles can also be used as resin particles. In this case, colored particles are formed by adding a colorant particle dispersion or the like to a dispersion of resin particles and then fusing in an aqueous medium.

  In particular, the method of fusing is preferably a method of salting out / fusing using resin particles produced by the polymerization step. When non-colored resin particles are used, the resin particles and the colorant particles can be salted out / fused in an aqueous medium.

  In addition to the colorant and the release agent, a charge control agent that is a component of the toner can be added as particles in this step.

  In addition, an aqueous medium here consists of water as a main component, and shows content whose water content is 50 mass% or more. Examples of those other than water include organic solvents that dissolve in water, and examples include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran.

(Other additives)
In addition to the resin, the colorant, and the release agent, the toner may be added with a material that can impart various functions as a toner material. Specific examples include charge control agents. These components can be added simultaneously with the resin particles and the colorant particles in the salting out / fusion step described above, and can be added by various methods such as a method included in the toner and a method of adding to the resin particles themselves.

  Similarly, various known charge control agents and those that can be dispersed in water can be used. Specific examples include nigrosine dyes, naphthenic acid or higher fatty acid metal salts, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, salicylic acid metal salts or metal complexes thereof.

(External additive)
To the toner of the present invention, so-called external additives can be added and used for the purpose of improving fluidity, chargeability and cleaning property. These external additives are not particularly limited, and various inorganic fine particles, organic fine particles and lubricants can be used. Usually, the particles before adding these external additives are often called colored particles, and the particles after the addition are often called toner or toner particles. However, both may be toner or toner particles.

  A conventionally well-known thing can be used as an inorganic fine particle. Specifically, silica, titanium, alumina fine particles and the like having a number average primary particle diameter of 5 to 500 nm can be preferably used. These inorganic fine particles are preferably hydrophobic.

  Specifically, as silica fine particles, for example, commercially available products R-805, R-976, R-974, R-972, R-812, R-809 manufactured by Nippon Aerosil Co., Ltd., HVK-2150, H manufactured by Hoechst -200, commercially available products TS-720, TS-530, TS-610, H-5, MS-5 and the like manufactured by Cabot Corporation.

  Examples of the titanium fine particles include commercial products T-805 and T-604 manufactured by Nippon Aerosil Co., Ltd., commercial products MT-100S, MT-100B, MT-500BS, MT-600, MT-600SS, and JA- 1. Commercial products TA-300SI, TA-500, TAF-130, TAF-510, TAF-510T manufactured by Fuji Titanium Co., Ltd. Commercial products IT-S, IT-OA, IT-OB, IT- manufactured by Idemitsu Kosan Co., Ltd. OC etc. are mentioned.

  Examples of the alumina fine particles include commercial products RFY-C and C-604 manufactured by Nippon Aerosil Co., Ltd. and commercial products TTO-55 manufactured by Ishihara Sangyo Co., Ltd.

  As the organic fine particles, spherical organic fine particles having a number average primary particle diameter of about 10 to 2000 nm can be used. As this, a homopolymer such as styrene or methyl methacrylate or a copolymer thereof can be used.

  Examples of lubricants include, for example, zinc stearate, aluminum, copper, magnesium, calcium, etc., zinc oleate, manganese, iron, copper, magnesium, etc., zinc palmitate, copper, magnesium, calcium, etc. And salts of higher fatty acids such as zinc of linoleic acid, salts of calcium, etc., zinc of ricinoleic acid, salts of calcium, etc.

  The amount of these external additives added is preferably 0.1 to 5% by mass with respect to the toner.

  As a method for adding the external additive, various known mixing apparatuses such as a Turbuler mixer, a Henschel mixer, a Nauter mixer, and a V-type mixer can be used.

  Next, preferred embodiments and performances of the present invention will be shown, and the present invention will be further described. However, of course, the embodiments of the present invention are not limited to these. In the text, “part” means “part by mass”.

Example 1
(Preparation of base material layer)
Base material layer composition Resin material: Polyphenylene sulfide (E2180, manufactured by Toray Industries, Inc.)
Crystallinity, melting point 280 ° C, glass transition point 90 ° C
Conductive filler: Acetylene black (HS-100, manufactured by Denka)
Lubricant: Calcium Montalate (1) Heat kneading Each raw material was melt-mixed using a twin-screw kneading extruder to pelletize the resin composition. The thermoplastic resin was dried at 130 ° C. for 8 hours before kneading and further cooled to about 60 ° C. before being used for kneading.

(2) Forming of base material layer belt of intermediate transfer body Using a 40 mm diameter extruder with a 6-thread spiral ring die having a lip width of 1 mm, the molten tube is extruded below the ring die in a molten tube state. The belt is cooled and solidified by coming into contact with the outer surface of the cooling mandrel mounted on the same axis via a support rod, and then the seamless belt is installed by the core installed in the seamless belt and the roll installed outside. Was removed while being held in a cylindrical shape, and the extrusion amount and take-up speed were adjusted so as to obtain the thickness described below, and a resin-made seamless intermediate transfer belt having a thickness of 150 μm was produced (this is referred to as intermediate transfer body A and To do).

(Formation of surface layer)
Preparation of intermediate transfer member B Resin material: Multifunctional acrylic monomer “KAYARAD PET30” (manufactured by Nippon Kayaku Co., Ltd.)
100 parts Polymerization initiator: “Irgacure 184” (manufactured by Ciba Specialty Chemicals)
1 part Conductive fine particles: Antimony-doped tin oxide “T-1” (manufactured by Mitsubishi Materials Corporation) 50 parts Lubricating filler: Tetrafluoroethane particle dispersion “NS-10S” (manufactured by Kitamura Chemical Co., Ltd.) 30 parts Leveling agent: Silicone oil “KF-54” (manufactured by Shin-Etsu Silicone Co., Ltd.) 0.1 part Diluting solvent: 2-butanol 1500 parts The above composition was mixed and stirred to prepare a surface layer coating solution. This coating solution is spray-coated on the intermediate transfer body, and after primary drying at 40 ° C. for 30 minutes, it is cured with an integrated light quantity of 600 mJ / cm ² with a mercury lamp having an ultraviolet intensity of 1 kw / cm ² , and the intermediate transfer is performed. Body B was prepared.

Preparation of intermediate transfer members C to F Intermediate transfer members C to F were prepared in the same manner as the intermediate transfer member B except that the acrylic monomer of the intermediate transfer member B was changed to the acrylic monomer or methacryl monomer of Table 1.

Preparation of intermediate transfer member G Similar to intermediate transfer member B, except that 20 parts of inorganic filler: “MEK Si sol” (manufactured by Nissan Chemical Industries, Ltd.) was further added to the surface layer. G was obtained.

Preparation of intermediate transfer member H Similar to intermediate transfer member B, except that 20 parts of titanium oxide: primary particle size 210 nm (manufactured by JR 405 Teica) was added to the surface layer. Obtained.

Preparation of intermediate transfer member I As in intermediate transfer member B, intermediate transfer member I was obtained in the same manner except that antimony-doped tin oxide was removed from the surface layer.

  The outline of the intermediate transfer member produced as described above is summarized in Table 1 below.

DPHA: KAYARAD DPHA (hexafunctional acrylic acid monomer; Nippon Kayaku)
PEG400DA: KAYARAD PEG400DA (bifunctional monomer; Nippon Kayaku)
(Note that 6/4 in the table means that 60 parts and 40 parts were used, respectively, and so on)
UX8101: Bifunctional urethane acrylate oligomer; Nippon Kayaku SR-350: Trimethylolpropane-trimethacrylate: Nippon Kayaku SR-480: Ethoxylated bisphenol A-dimethacrylate: Nippon Kayaku Ir-184: 1-hydroxy-cyclohexyl- Phenyl ketone (Ciba Specialty Chemicals)
Preparation of toner (preparation example 1 of resin particles)
In a flask equipped with a stirrer, 72.0 g of wax (pentaerythritol tetrastearate) was added to the monomer mixture consisting of 115.1 g of styrene, 42.0 g of n-butyl acrylate and 10.9 g of methacrylic acid. Then, the solution was heated to 80 ° C. and dissolved to prepare a monomer solution.

  Meanwhile, 7.08 g of an anionic surfactant (sodium dodecylbenzenesulfonate: SDS) was dissolved in 2760 g of ion-exchanged water in a 5000 ml separable flask equipped with a stirrer, a temperature sensor, a condenser, and a nitrogen introducing device. A surfactant solution (aqueous medium) was charged, and the internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream. Next, the monomer solution (80 ° C.) was mixed and dispersed in the surfactant solution (80 ° C.) with a mechanical disperser “CLEAMIX” (manufactured by M-Technique Co., Ltd.) having a circulation path. An emulsified liquid in which emulsified particles (oil droplets) having a dispersed particle diameter were dispersed was prepared.

  An initiator solution prepared by dissolving 0.84 g of a polymerization initiator (potassium persulfate: KPS) in 200 g of ion-exchanged water was added to this dispersion, and the system was heated and stirred at 80 ° C. for 3 hours. A polymerization reaction was performed. A solution obtained by dissolving 7.73 g of a polymerization initiator (KPS) in 240 ml of ion-exchanged water was added to the obtained reaction solution, and after 15 minutes, the temperature was adjusted to 80 ° C., followed by 383.6 g of styrene and n-butyl. A mixture of 140.0 g of acrylate, 36.4 g of methacrylic acid and 12 g of n-octyl mercaptan was added dropwise over 100 minutes. The system was heated and stirred at 80 ° C. for 60 minutes, and then the system was heated to 40 ° C. By cooling, a dispersion of resin particles containing wax (hereinafter also referred to as “latex (1)”) was prepared.

  On the other hand, 9.2 g of sodium n-dodecyl sulfate was stirred and dissolved in 160 ml of ion-exchanged water. While stirring this solution, 20 g of carbon black “MOGAL L” (Cabot Corp.) is gradually added as a colorant, and then dispersed using a mechanical disperser “CLEAMIX” (M Technique Corp.). As a result, a colorant dispersion (1) was prepared. When the particle diameter of the colorant particles in the colorant dispersion (1) was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.), the mass average particle diameter was 120 nm.

(Preparation Example K1 of colored particles)
1250 g of latex (1) (solid) in a 5 liter reaction vessel (four-necked flask) equipped with a temperature sensor, cooling tube, stirrer (having two stirrer blades, crossing angle 20 °), and shape monitoring device Minute conversion), 2000 ml of ion-exchanged water, and the whole amount of the colorant dispersion (1) were prepared, and the internal temperature was adjusted to 25 ° C. Then, a 5 mol / liter sodium hydroxide aqueous solution was added to the dispersion mixed solution to adjust the pH. Was adjusted to 10.0. Next, an aqueous solution in which 52.6 g of magnesium chloride hexahydrate was dissolved in 72 ml of ion-exchanged water was added over 10 minutes at 25 ° C. with stirring. Thereafter, the temperature increase was started immediately, and the system was heated to 95 ° C. over 5 minutes (temperature increase rate: 14 ° C./min).

  In this state, the particle size of the associated particles was measured with “Coulter Counter TA-II”, and when the volume average particle size reached 6.5 μm, an aqueous solution in which 115 g of sodium chloride was dissolved in 700 ml of ion-exchanged water was added. Then, the particle growth is stopped, and further, the mixture is heated and stirred at a liquid temperature of 90 ° C. for 8 hours (stirring rotation speed: 120 rpm) to continue the aging treatment, and then the system is heated to 10 ° C./min. The mixture was cooled to 30 ° C. under the above conditions, hydrochloric acid was added to adjust the pH to 3.0, and stirring was stopped.

  The produced particles are filtered, washed repeatedly with ion-exchanged water, classified in liquid with a centrifugal separator, and then dried using a flash jet dryer to give colored particles having a moisture content of 1.0% (hereinafter referred to as “ Colored particles (K1) ”) were obtained.

(Preparation Example 2 of Colorant Dispersion)
Dispersion of colorant particles in the same manner as in Preparation Example 1 of the colorant dispersion, except that 20 g of the pigment “CI Pigment Yellow 74” was used instead of 20 g of carbon black in Preparation Example 1 of the colorant dispersion. A liquid (hereinafter referred to as “colorant dispersion (2)”) was prepared. When the particle diameter of the colorant particles in the obtained colorant dispersion (2) was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.), the mass average particle diameter was 120 nm. there were.

(Colorant Dispersion Preparation Example 3)
In Preparation Example 1 of Colorant Dispersion, Colorant was prepared in the same manner as Preparation Example 1 of Colorant Dispersion except that 20 g of quinacridone-based magenta pigment “CI Pigment Red 122” was used instead of 20 g of carbon black. A particle dispersion (hereinafter referred to as “colorant dispersion (3)”) was prepared. When the particle diameter of the colorant particles in the obtained colorant dispersion (3) was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.), the mass average particle diameter was 120 nm. there were.

(Preparation Example 4 of Colorant Dispersion)
In Preparation Example 1 of Colorant Dispersion, the same procedure as in Preparation Example 1 of Colorant Dispersion was used, except that 20 g of phthalocyanine cyan pigment “CI Pigment Blue 15: 3” was used instead of 20 g of carbon black. A dispersion of colorant particles (hereinafter referred to as “colorant dispersion (4)”) was prepared. When the particle diameter of the colorant particles in the obtained colorant dispersion (4) was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.), the mass average particle diameter was 120 nm. there were.

(Preparation example Y1 of colored particles)
Colored particles (Y1) were obtained in the same manner as in Colored Particle Preparation Example K1, except that the whole amount of the colorant dispersion (1) was used instead of the whole amount of the colorant dispersion (1).

(Preparation Example M1 of colored particles)
Colored particles (M1) were obtained in the same manner as in Colored Particle Preparation Example K1, except that in Colored Particle Preparation Example K1, the entire amount of Colorant Dispersion Liquid (1) was used instead of the total amount of Colorant Dispersion Liquid (1). .

(Preparation example C1 of colored particles)
Colored particles (C1) were obtained in the same manner as in Colored Particle Preparation Example K1, except that in Colored Particle Preparation Example K1, the entire amount of Colorant Dispersion Liquid (1) was used instead of the total amount of Colorant Dispersion Liquid (4). .

(Manufacture of toner)
For the above colored particles, 0.8 part by mass of hydrophobic silica (number average primary particle size = 12 nm, degree of hydrophobicity = 65) and 0 of hydrophobic titania (number average primary particle size = 30 nm, degree of hydrophobicity = 55) .5 parts by mass was added and mixed with a Henschel mixer to obtain a toner. These are black (Bk) toner, yellow (Y) toner, magenta (M) toner, and cyan (C) toner.

A polymerized toner having a volume median diameter (D ₅₀ ) of 6.5 μm was prepared and used.

  Each of these toners is displayed as follows according to the type of added fatty acid metal salt.

Addition of fatty acid metal salt Toner series (1): 0.15% by mass of zinc stearate was added to each color toner.

  Toner series (2): 0.15% by mass of calcium stearate was added to each color toner.

  Toner Series (3): No fatty acid metal salt was added to each color toner.

[Performance evaluation]
The above color toners were combined with the following processes for performance evaluation.

Process 1 (with fatty acid metal salt coating mechanism on the intermediate transfer member)
Conduction with the core metal using a 10 denier rayon conductive yarn as the conductive fiber and a cloth implanted in the base fabric with W weave so that the fiber density is 200 × 10 ³ (pieces / 2.54 cm ² ). Was wound in a spiral shape to obtain a brush-like roll having a diameter of 16 mm.

  As shown in FIG. 2, it was attached to the intermediate transfer member and the biting amount was set to 0.7 mm.

  The lubricant was 8 mm in diameter, and the tip of the brush contacted with 1 mm of the amount of biting into the lubricant. The brush rotated at a linear speed of 1.2 times in the same direction as the rotation direction of the intermediate transfer member.

Process 2 (with fatty acid metal salt coating mechanism on the photoreceptor)
Conductivity with the core metal using a 5 denier rayon conductive yarn as the conductive fiber and a fabric planted in a base fabric with a W weave so that the fiber density is 200 × 10 ³ (pieces / 2.54 cm ² ). Was wound in a spiral shape to obtain a brush-like roll having a diameter of 16 mm.

  As shown in FIG. 2, it was attached to the photoreceptor and the biting amount was set to 0.7 mm.

  The lubricant was 8 mm in diameter and the tip of the brush contacted with 1 mm of the amount of biting into the lubricant, and the brush rotated at a linear speed of 1.2 times in the same direction as the rotation direction of the electrophotographic photosensitive member.

Process 3 (No fatty acid metal salt coating mechanism on both intermediate transfer member and photoreceptor)
Image evaluation (transfer rate)
The following image characteristics were evaluated on actual machines under the conditions of 30 ° C. and 80% RH (HH environment).

As for transfer efficiency, toner movement during secondary transfer when a two-color superimposed solid image is printed using a polymer printer with a volume median diameter (D ₅₀ ) of 6.5 μm in a Konica Minolta color printer “MAGICCOLOR2300” Was evaluated as transfer efficiency. The secondary transfer efficiency is the ratio of the toner mass of the toner image transferred onto the recording paper to the toner mass of the toner image transferred onto the intermediate transfer belt. When the secondary transfer efficiency is 95% or more, “◎”, less than 95% 90% or more is indicated by “◯”, less than 90% 85% or more is indicated by “△”, and less than 85% is rejected. “×”.

Image noise evaluation (cleaning (CL) defect)
The four-color toner images of yellow, magenta, cyan and black are transferred from the intermediate transfer belt onto the recording paper, and the image quality after the transfer is visually determined and ranked as follows, and “◎”, “○”, “△”, “ “×”.

  A4 color coverage 20% (each color character pattern and solid part, 5% coverage per color (test chart area of single color toner / test paper area)) Test chart with 20,000 prints in HH environment And evaluated.

  Due to the abrasion of the cleaning blade of the intermediate transfer belt, it does not appear as image noise after transfer to the recording paper, and “◎” indicates that there is almost no cleaning failure on the belt, but it does not appear as image noise after transfer to the recording paper. Above, a level with a little cleaning failure is indicated by “◯”, and a level that appears as a slight but slight image noise on the recording paper is indicated by “Δ”. In addition, after transfer to the recording paper, it appeared considerably as image noise, and the level not to be evaluated was indicated by “x”.

  Furthermore, the abrasion state of the blade edge was evaluated with a laser microscope (manufactured by Lasertec Corporation) at an objective of 50 times at the end of 20,000 printing.

  When the wear width at this time is 20 μm or less, it is ◯, 20 μm, but when there is no edge chipping, Δ20 μm or more, and when there is edge chipping, it is ×.

  As the evaluation machine, Konica Minolta 8050 was modified and used as shown in the table.

  The evaluation results are shown below by using the intermediate transfer members as shown in Tables 2, 4, and 6 and evaluating them under the conditions as shown in Tables 3, 5, and 7.

  When the performance is evaluated by applying a fatty acid metal salt to the intermediate transfer body with a brush

  When the toner contains a fatty acid metal salt and the performance is evaluated

  When performance is evaluated by applying a fatty acid metal salt to the photoconductor with a brush

  As shown in Tables 3, 5, and 7, good results were obtained when the toner, intermediate transfer member, and photoconductor contained a fatty acid metal salt.

FIG. 3 is a conceptual cross-sectional view illustrating an example of a layer configuration of an intermediate transfer member. The figure explaining an example of the fatty-acid metal salt application | coating method to a photoreceptor and an intermediate transfer body. 1 is a cross-sectional configuration diagram illustrating an example of an image forming apparatus using an intermediate transfer member of the present invention.

Explanation of symbols

1Y, 1M, 1C, 1K photoconductor (electrostatic latent image carrier)
5Y, 5M, 5C, 5K Primary transfer roller 6A Cleaning means 7 Intermediate transfer body unit 8 Housing 10Y, 10M, 10C, 10K Image forming section 70 Intermediate transfer body 701 Base material layer 702 Surface layer A Apparatus body P Recording member

Claims (7)

In an image forming apparatus in which a toner image formed by development on an electrophotographic photosensitive member is primarily transferred to an intermediate transfer member, and then the toner image is secondarily transferred from the intermediate transfer member to a transfer material. It has at least a base material layer and a surface layer, and the surface layer contains a cured acrylic acid resin or a cured methacrylic acid resin as main components, and the toner contains a fatty acid metal salt. Image forming apparatus. In an image forming apparatus in which a toner image formed by development on an electrophotographic photosensitive member is primarily transferred to an intermediate transfer member, and then the toner image is secondarily transferred from the intermediate transfer member to a transfer material. It has at least a base material layer and a surface layer, and the surface layer contains a cured acrylic acid resin or a cured methacrylic acid resin as a main component, and has a mechanism for applying a fatty acid metal salt to the surface of the intermediate transfer member. An image forming apparatus. In an image forming apparatus in which a toner image formed by development on an electrophotographic photosensitive member is primarily transferred to an intermediate transfer member, and then the toner image is secondarily transferred from the intermediate transfer member to a transfer material. Having at least a base material layer and a surface layer, the surface layer containing a cured acrylic acid resin or a cured methacrylic acid resin as a main component, and a mechanism for applying a fatty acid metal salt to the surface of the electrophotographic photosensitive member An image forming apparatus comprising: The image forming apparatus according to claim 1, wherein the fatty acid metal salt is selected from calcium stearate, aluminum stearate, and zinc stearate. The image forming apparatus according to claim 1, wherein the surface layer contains a metal oxide. The image forming apparatus according to claim 1, wherein the metal oxide is silica. An image forming method used in the image forming apparatus according to claim 1.

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