JP4437901B2 - Image forming apparatus and combination of developer used therefor - Google Patents

Description

【０１０８】
実施例１ないし４に示すように、本発明に係る現像剤の組合せを適用した装置では、長時間放置後も白スジの発生もなく、感光ドラムの膜削れが少なかった。また、実施例５及び６に示すように、第２もしくは第３のユニットにて使用される現像剤の金属石鹸の添加量が１０部よりも多い場合及び第１のユニットにて使用される現像剤の金属石鹸の添加量が２部よりも多い場合には白スジの発生が多少見られた。また、比較例１及び２に示すように、第１のユニットと第２もしくは第３ユニットにて使用される現像剤の金属石鹸量が同量である場合、第１ユニットにて使用される現像剤の金属石鹸の添加量が、第２もしくは第３ユニットにて使用される現像剤の金属石鹸の添加量よりも多い場合白スジの発生、または感光ドラムの膜削れについて良好な結果が得られなかった。
【０１０９】
【発明の効果】
本発明によれば、ブレード表面における金属石鹸の固着、及び像担持体の膜削れを防止し、良好な画像を形成し得る。
【図面の簡単な説明】
【図１】 本発明の画像形成装置の一例を表す概略図
【図２】 現像スリーブとブレードの位置関係の一例を表す図
【図３】 現像スリーブとブレードの位置関係の一例を表す図
【図４】 現像スリーブとブレードの位置関係の一例を表す図
【符号の説明】
１…画像形成装置、７…中間転写ベルト機構、７ａ…ベルト、１１Ｂ…黒色現像ユニット、９…定着装置、１２…リボルバー、１２Ｙ，１２Ｍ，１２Ｃ…現像ユニット、１３…回転現像装置、１４…感光ドラム、２１Ｙ，２１Ｍ，２１Ｃ…ブレード、２２Ｙ，２２Ｍ，２２Ｃ…現像スリーブ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus for developing an electrostatic charge image and a magnetic latent image in an electrophotographic method, an electrostatic printing method, a magnetic recording method, and the like, and a developer used therefor, and in particular, one image carrier. The present invention relates to an image forming apparatus in which a body and a rotary developing device including a plurality of developing units are provided to face each other, and a developer used therefor.
[0002]
[Prior art]
In full-color electrophotography, an electrostatic latent image is formed on an image carrier, the latent image is then developed with toner, the toner image is transferred to a transfer material such as paper, and then fixed by heating, pressing, or the like. . Regarding the toner to be used, in order to form a full color image as well as the conventional single color black, an image is formed using a plurality of toners. These full-color image forming apparatuses require a plurality of developing units. Although each developing device can be independently provided on the photoconductor to enable high-speed printing, there is a problem that the image forming apparatus becomes large.
[0003]
Therefore, a developing unit containing the developer of each color is accommodated in the rotating developer, and the rotating developer is provided so as to be close to the image carrier, and the developing unit is rotated to each developing unit. There is known a so-called rotary developing device that sequentially conveys the toner to the developing area and develops the electrostatic latent image on the image carrier with each color toner (see, for example, Patent Document 1).
[0004]
Similarly to miniaturization, for example, in order to extend the life of the image carrier, a metal soap is included in the used toner, and the surface of the image carrier is covered, so that the amount of film scraping of the image carrier is reduced. Techniques that can be reduced are known.
[0005]
However, this metal soap may generate soft caking near the regulating blade on the developing sleeve. In particular, in the rotary type developing device, the same developing device is always arranged at the same position when stopped. In the developing device arranged at the bottom, the regulating blade is directed upward, and the developer can be left for a long time in a state where the developer covers the gap between the regulating blade surface and the developing sleeve. At this time, soft caking tends to occur near the blade of the developing sleeve disposed at the bottom due to the weight of the developer. As a result, the image forming apparatus cannot perform normal development and tends to be a defective image. In addition, it is known that when a large amount of metal soap is used for the purpose of protecting the image carrier, the developing sleeve reduces the force of conveying the developer.
[0006]
[Patent Document 1]
JP-A-2-212867
[0007]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION A first object of the present invention is to provide an image forming apparatus capable of forming a good image by preventing the metal soap from sticking to the blade surface and preventing the film of the image carrier from being scraped.
[0008]
A second object of the present invention is to provide a developer capable of forming a good image by preventing the metal soap from adhering to the blade surface and film scraping of the image carrier.
[0009]
[Means for Solving the Problems]
The image forming apparatus of the present invention is firstly provided with a rotatable developer carrying member for supplying the developer to the photoreceptor, and a width direction on the circumferential surface of the developer carrying member. An image forming apparatus having a rotary developing device having a blade for regulating the thickness of a developer layer carried on the surface of a carrying member, and having two or more development units each containing a developer of different color Because
When the rotary developer is stopped, Developer carrying member In the direction of rotation Against The blade and the Developer carrying member The blade surface located upstream from the position facing the , With respect to the vertical axis Along the direction of rotation The developing unit having an angle of 45 degrees to 135 degrees is designated as the first developing unit, Developer carrying member In the direction of rotation Against The blade and the Developer carrying member The blade surface located upstream from the position facing the , With respect to the vertical axis Along the direction of rotation When the developing unit whose angle formed is other than 45 degrees to 135 degrees is set as the second developing unit,
The second developer contained in the second developing unit includes a toner containing a colorant, a binder resin, and a metal soap,
The first developer contained in the first developing unit contains a metal soap in an amount less than the amount of the metal soap contained in the colorant, the binder resin and the second developer, or does not contain the metal soap. It contains toner.
[0010]
In addition, the developer combination of the present invention is, secondly, a rotatable developer carrying member for supplying the developer to the photoreceptor, and a width direction on the circumferential surface of the developer carrying member, A combination of developers respectively applied to each developing unit of a rotary developing device including two or more developing units having blades for regulating the thickness of a developer layer carried on the surface of the developer carrying member. And
When the rotary developer is stopped, Developer carrying member In the direction of rotation Against The blade and the Developer carrying member The blade surface located upstream from the position facing the , With respect to the vertical axis Along the direction of rotation The developing unit having an angle of 45 degrees to 135 degrees is designated as the first developing unit, Developer carrying member In the direction of rotation Against The blade and the Developer carrying member The blade surface located upstream from the position facing the , With respect to the vertical axis Along the direction of rotation When the developing unit whose angle formed is other than 45 degrees to 135 degrees is set as the second developing unit,
More than the amount of the metal developer contained in the second developer unit and containing the toner containing the colorant, the binder resin and the metal soap, and the metal soap contained in the colorant, the binder resin and the second developer. It has a combination with a first developer containing a toner containing a small amount of metal soap or containing no metal soap.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The image forming apparatus according to the present invention is provided with a rotatable developer carrying member for supplying the developer to the photoconductor and a width direction on the circumferential surface of the developer carrying member, and carried on the surface of the developer carrying member. Each of which has a blade for regulating the thickness of the developer layer, each of which has a rotary type developer unit having two or more development units containing different color developers, and when the rotary type developer unit is stopped. The content of the metal soap in the developer accommodated in the first developing unit located at the lowermost position is different from that of the second developing unit located above it.
[0012]
The first developer accommodated in the first developing unit contains a colorant and a binder resin and does not contain a metal soap or contains a small amount. A preferable addition amount is 0 or more and 2% by weight or less based on the total amount of toner.
[0013]
The developer accommodated in the second developing unit includes a colorant, a binder resin, and metal soap, and the content of the metal soap is larger than that of the first developer. Preferably, it is greater than 0 and not more than 10% by weight with respect to the total amount of toner.
[0014]
In the present invention, the content of the above-described metal soap is appropriately determined depending on the angle of the blade provided in each developing device, contamination of the metal soap on the developer carrying member, and the protective effect on the film thickness of the image carrier. Can be done.
[0015]
Further, the developer combination of the present invention is a developer combination applied to the rotary developing device, which is accommodated in the first developing unit, contains a colorant and a binder resin, and contains metal soap. A first developer containing a toner that does not contain or contains a small amount of metal soap, and a metal that is contained in the second development unit and is more than the metal soap content of the colorant, binder resin, and first developer. And a second developer containing toner containing soap.
[0016]
Hereinafter, the present invention will be specifically described with reference to the drawings.
[0017]
FIG. 1 is a schematic view showing an example of an image forming apparatus of the present invention.
[0018]
The color image forming apparatus 1 includes a paper feed unit 2 having two stages of paper feed cassettes 2a and 2b and a manual feed unit 3 provided separately. The recording paper fed from the paper feed unit 2 or the manual feed unit 3 moves up the vertical conveyance path 5 and reaches the secondary transfer roller 6. When the recording paper passes between the secondary transfer roller 6 and the belt 7a of the intermediate transfer belt mechanism 7, the toner image of each color is transferred from the belt 7a. The recording paper on which the toner image has been transferred is heated and pressed and fixed when passing between the pressure roller 9a and the heating roller 9b of the fixing device 9. In the figure, 10 indicates a duplex unit.
[0019]
The intermediate transfer belt mechanism 7 and its peripheral devices will be described.
[0020]
Around the photosensitive drum 14, there are a charging device 17, a developing mechanism that accommodates developer of four colors of yellow (Y), magenta (M), cyan (C), and black (B), an intermediate transfer belt mechanism 7, and a drum Each cleaner 18 is provided. In this developing mechanism, the B developing unit 11B and the B developing unit 11B are provided separately, and have a rotary developing unit having Y, M, and C developing units 12Y, 12M, and 12C incorporated in the revolver 12. The Y, M, and C developing units 12Y, 12M, and 12C and the B developing unit 11B each carry toner and supply developing sleeves 22Y, 22M, and 22C to the photoreceptor, and developing sleeves 22Y, 22M, and 22C surfaces The blades 21Y, 21M, and 21C are disposed at a predetermined angle to regulate the thickness of the developer layer carried on the surface.
[0021]
Each developing unit develops and visualizes the electrostatic latent image previously formed on the surface of the photosensitive drum 14 by the exposure device 15 using toner of each color, and forms a toner image. The obtained toner image is transferred to the belt 7 a and further transferred to the recording paper at a position between the belt 7 a and the secondary transfer roller 6.
[0022]
2 to 4 are model diagrams showing the positional relationship between the developing sleeves 22Y, 22M, and 22C and the blades 21Y, 21M, and 21C in FIG. 1, respectively.
[0023]
As shown in FIG. 2, in the C developing unit 12C, a blade 21C is provided at a predetermined interval with respect to the developing sleeve 22C rotating in the direction of the arrow, and the surface opposite to the rotating direction of the developing sleeve 22C. The blade 21 </ b> C surface 23 </ b> C faces upward, and is in a state where the developer tends to accumulate when stopped.
[0024]
In the present invention, as shown in FIGS. 2 to 4, the direction of the blade is represented by an angle formed by the blade with respect to its horizontal and vertical axes. For example, in FIG. 2, the position of the blade 21C is 90 °.
[0025]
In the present invention, the upward direction of the blade means the direction in which the developer tends to accumulate on the surface of the blade.
[0026]
Furthermore, in the present invention, the downward direction of the blade refers to a direction other than upward.
[0027]
In FIG. 3, the blade direction of the Y developing unit 12Y is at 210 °, the surface 23Y of the blade 21Y is downward, and the developer does not accumulate.
[0028]
In FIG. 4, the blade direction of the M developing unit 12M is at 330 °, and the surface 23M of the blade 21M is downward, so that the developer does not accumulate.
[0029]
As shown in FIGS. 1 to 4, the first developing unit 12 </ b> C located at the lowermost position when the rotary developing device is stopped is such that the surface where the blade disposed on the developer carrying member comes into contact with the developer faces upward, Developer tends to accumulate. However, according to the present invention, the developer used in the lowermost developing unit when the rotary developing device is stopped does not contain metal soap or has a low content, so even if the developer is Even if the blade stops in an upward direction that tends to accumulate, the metal soap does not adhere to the surface. On the other hand, by adding more metal soap to the developer of the other developing units above the first developing unit when the rotary developing device is stopped, the metal soap is sufficiently distributed to the image carrier such as the photosensitive drum, Film scraping of the image carrier can be sufficiently prevented.
[0030]
In FIG. 1, as an example of the image forming apparatus of the present invention, a rotary developing device containing three color developers of Y, M, and C and a black developing device containing B developer are separately provided. Although an apparatus provided is shown, the effect of the present invention is that an image forming apparatus provided with a rotary developing device accommodates developers of four colors Y, M, C, and B, for example. Alternatively, a separate developing device may not be provided, or for example, developers of at least two colors of Y, M, C, and B may be accommodated, and one or more developing devices may be provided separately. In this apparatus, the C developing unit is arranged at the lowest position when stopped, but the Y or M developing unit can be arranged below when stopped when necessary.
[0031]
In addition to the binder resin, the colorant, and the metal soap, a wax, a charge control agent, other external additives, and the like can be added to the developer of the present invention as necessary.
[0032]
Examples of the metal soap used in the present invention include zinc stearate, calcium stearate, aluminum stearate, magnesium stearate, cobalt stearate, and barium stearate. Preferably, zinc-containing materials such as zinc stearate, zinc laurate and zinc pt-butylbenzoate can be used.
[0033]
The first developer contained in the first developing unit does not contain metal soap, or the preferable addition amount of metal soap is greater than 0 and not more than 2% by weight with respect to the total amount of toner. If it exceeds 2% by weight, the metal soap tends to adhere to the vicinity of the blade due to its own weight, and the predetermined developer amount tends not to be conveyed.
[0034]
The content of the metal soap in the second developer accommodated in the second developing unit is preferably greater than 0 and 10% by weight or less with respect to the total amount of toner. When the amount exceeds 10% by weight, the development is repeatedly performed, so that the metal soap covers the developing sleeve, and the force for conveying the developer tends to decrease.
[0035]
Further, in the case where a third developing unit, a fourth developing unit, and the like are further provided in one rotary developing unit, the developer used is included in the first developer, as with the second developer. The amount of metal soap is greater than the amount of metal soap and the content is greater than 0 and not more than 10% by weight. Further, the amount of the developer other than the first developer may be the same as or different from each other, and can be appropriately changed as necessary.
[0036]
The metal soap content of the developer contained in a single developer provided separately from the rotary developer can be set as required, and even if it is greater than the amount of metal soap contained in the first developer, it is less However, the same amount may be used.
[0037]
Examples of the binder resin include styrene acrylic, polyester, polyurethane, and epoxy resin.
[0038]
Examples of styrene / acryl include styrene polymers, copolymers of styrenes and dienes, copolymers of styrenes and alkyl (meth) acrylates, and the like. Particularly preferred is styrene.
[0039]
As polyester, for example, as a raw material monomer for polyester, a divalent or higher valent alcohol component and a carboxylic acid component such as a divalent or higher carboxylic acid, carboxylic acid anhydride, or carboxylic acid ester are used.
[0040]
As the colorant, carbon black, organic or inorganic pigments or dyes are used.
[0041]
In carbon black, for example, acetylene black, furnace black, thermal black, channel black, and ketjen black, face dyes include, for example, First Yellow G, Benzidine Yellow, Indian Fast Orange, Irgadin Red, Carmine FB, Permanent Bordeaux FRR, Pigment Orange R, Resol Red 2G, Lake Red C, Rhodamine FB, Rhodamine B Lake, Phthalocyanine Blue, Pigment Blue, Brilliant Green B, Phthalocyanine Green, Quinacridone and the like can be used alone or in combination.
[0042]
Examples of the wax include aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, polyolefin copolymer, polyolefin wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax, and aliphatic carbonization such as acid value polyethylene wax. Oxide of hydrogen wax or block copolymer thereof, candelilla wax, carnauba wax, wax based on wax, jojoba wax, rice wax, animal wax such as beeswax, lanolin, whale wax, ozokerite Mineral waxes such as ceresin and petrolactam, waxes based on fatty acid esters such as montanic acid ester wax and castor wax, and fatty acid esters such as deoxidized carnauba wax. Those deoxidizing is raised part or all.
[0043]
As the charge control agent, a metal-containing azo compound is used, and the metal element is preferably a complex, complex salt of iron, cobalt, chromium, or a mixture thereof. Metal-containing salicylic acid derivative compounds are also used, and the metal element is preferably a complex, complex salt of zirconium, zinc, chromium, boron, or a mixture thereof.
[0044]
In order to adjust the fluidity and chargeability of the toner particles, inorganic fine particles may be externally mixed. For example, as such inorganic fine particles, silica, titania, alumina, strontium titanate, tin oxide, etc. may be used. These can be used alone or in combination of two or more. The inorganic fine particles are preferably surface-treated with a hydrophobizing agent from the viewpoint of improving environmental stability. In addition to such inorganic oxides, resin fine particles of 1 μm or less can be added to improve the cleaning property.
[0045]
The developer of the present invention can be produced using a known polymerization method or pulverization method.
[0046]
【Example】
EXAMPLES Hereinafter, an Example is shown and this invention is demonstrated more concretely.
[0047]
Unless otherwise specified, hereinafter, all parts represented by “parts” represent “parts by weight”.
[0048]
Example 1
Four toner particle materials of Y, M, C, and B having the following compositions were prepared.
[0049]
Toner particle material composition
92 parts of binder resin (polyester resin)
5 parts of colorant
2 parts of wax (propylene wax)
Charge control agent (quaternary ammonium salt) 1 part
As the colorant, first yellow G as a Y colorant, Carmine FB as an M colorant, phthalocyanine blue as a C colorant, and acetylene black as a B colorant, respectively, were used to obtain toner particles of four colors.
[0050]
The toner particle materials of the four colors yellow, magenta, cyan, and black were mixed using a Henschel mixer, and then melt-kneaded using a biaxial extruder.
[0051]
The obtained melt-kneaded product was cooled, coarsely pulverized with a hammer mill, and then finely pulverized and classified with a jet pulverizer to obtain toner particles of four colors having a volume average diameter of 8.0 μm.
[0052]
0.3 parts of silicon dioxide each having a primary particle diameter of 12 nm and 0.3 parts each of titanium dioxide having a primary particle diameter of 20 nm are added to the obtained toner particles of four colors, and zinc steak which is a metal soap is further added. The rate is not added to the yellow toner particles, but 0.01 parts are added to the magenta toner particles, 0.01 parts to the cyan toner particles, and 0.01 parts to the black toner particles. Each color toner was produced.
[0053]
Next, 6 parts of each of the above toners were mixed with 94 parts of a silicone-coated carrier to prepare four color developers.
[0054]
Thereafter, each developer was applied to each developing unit of the image forming apparatus having the same configuration as in FIG.
[0055]
Thereafter, the C developing unit is set to 120 ° for the Y developing unit and 240 ° to the M developing unit so that the angle formed by the regulating blade with respect to the horizontal and vertical axes is 0 °. Immediately after being left in the wet for 24 hours, solid images of each color were formed.
[0056]
In this arrangement, the Y developing unit is arranged at the lowermost position, and the metal soap content of the developer contained in the Y developing unit is compared with the metal soap content of the developer contained in the M and C developing units. , Is the least.
[0057]
Thereafter, 20000 sheets were passed to form solid images of each color.
[0058]
White streaks did not occur in any of the images after 24 hours and after feeding 20,000 sheets, and good images could be obtained. Moreover, the film scraping amount of the photosensitive drum after passing 20,000 sheets was 18 μm, and it was confirmed that a good image was obtained up to a predetermined life number.
[0059]
The results are shown in Table 1 below.
[0060]
Example 2
Development of four colors in the same manner as in Example 1 except that the amount of zinc stearate added is 2.0 parts cyan, 10.0 parts yellow, 10.0 parts magenta, and 0.01 parts black. An agent was obtained.
[0061]
Thereafter, each developer was applied to each developing unit of the image forming apparatus having the same configuration as in FIG.
[0062]
The arrangement of each developing unit was the same as in FIG. That is, the C developing unit was disposed at the lowermost part of the rotary developing device, and the angle formed by the regulating blade with respect to the horizontal and vertical axes was set to 90 °. The Y developing unit was set to 210 ° and the M developing unit was set to 330 °. Thereafter, immediately after being left for 24 hours at room temperature and humidity, solid images of each color were formed.
[0063]
In this arrangement, the C developing unit is arranged at the bottom, and the metal soap content of the developer contained in the C developing unit is compared with the metal soap content of the developer contained in the other two color developing units. It is the least.
[0064]
Thereafter, 20000 sheets were passed to form solid images of each color.
[0065]
White streaks did not occur in any of the images after 24 hours and after feeding 20,000 sheets, and good images could be obtained. Further, the film thickness of the photosensitive drum after passing 20,000 sheets was 8 μm, and it was confirmed that a good image was obtained up to a predetermined life number.
[0066]
The results are shown in Table 1 below.
[0067]
Example 3
Development of four colors in the same manner as in Example 1 except that the amount of zinc stearate was changed to 5.0 parts cyan, 2.0 parts yellow, 10.0 parts magenta, and 0.01 parts black, respectively. An agent was obtained. Each developer was applied to each developing unit of the image forming apparatus having the same configuration as in FIG.
[0068]
The arrangement of each developing unit was set so that the angle formed by the regulating blade of the C developing unit with respect to the horizontal / vertical axis was 15 °. The Y developing unit was set to 135 ° and the M developing unit was set to 255 °. Thereafter, immediately after being left for 24 hours at room temperature and humidity, solid images of each color were formed.
[0069]
In this arrangement, the Y developing unit is arranged at the lowermost position, and the metal soap content of the developer contained in the Y developing unit is compared with the metal soap content of the developer contained in the M and C developing units. , Is the least.
[0070]
Thereafter, 20000 sheets were passed to form solid images of each color.
[0071]
White streaks did not occur in any of the images after 24 hours and after feeding 20,000 sheets, and good images could be obtained. Moreover, the film scraping amount of the photosensitive drum after passing 20,000 sheets was 10 μm, and it was confirmed that a good image was obtained up to a predetermined life number.
[0072]
The results are shown in Table 1 below.
[0073]
Example 4
A four-color developer was obtained in the same manner as in Example 1 except that the amount of zinc stearate added was changed to 10 parts cyan, 0.01 parts yellow, 0 parts magenta, and 0.01 parts black. Each developer was applied to each developing unit of the image forming apparatus having the same configuration as in FIG.
[0074]
The arrangement of each developing unit was set such that the angle formed by the regulating blade of the C developing unit with respect to the horizontal / vertical axis was 165 °. The Y developing unit was set to 285 ° and the M developing unit was set to 45 °. Thereafter, immediately after being left for 24 hours at room temperature and humidity, solid images of each color were formed.
[0075]
In this arrangement, the M developing unit is arranged at the lowermost position, and the metal soap content of the developer contained in the M developing unit is compared with the metal soap content of the developer contained in the Y and C developing units. , Is the least.
[0076]
Thereafter, 20000 sheets were passed to form solid images of each color.
[0077]
White streaks did not occur in any of the images after 24 hours and after feeding 20,000 sheets, and good images could be obtained. Moreover, the film scraping amount of the photosensitive drum after passing 20,000 sheets was 19 μm, and it was confirmed that a good image was obtained up to a predetermined life number.
[0078]
The results are shown in Table 1 below.
[0079]
Comparative Example 1
A four-color developer was obtained in the same manner as in Example 1 except that the amount of zinc stearate added was changed to 0 part cyan, 0 part yellow, 0.01 part magenta, and 0.01 part black. Each developer was applied to each developing unit of the image forming apparatus having the same configuration as in FIG.
[0080]
The arrangement of each developing unit was set so that the angle formed by the regulating blade of the C developing unit with respect to the horizontal and vertical axes was 0 °. The Y developing unit was set to 120 °, and the M developing unit was set to 240 °.
[0081]
In this arrangement, the Y developing unit is arranged at the lowermost position, and the metal soap content of the developer contained in the Y developing unit is equal to the metal soap content of the developer contained in the C developing unit. Amount and no added amount.
[0082]
Thereafter, immediately after being left for 24 hours at room temperature and humidity, solid images of each color were formed.
[0083]
Thereafter, 20000 sheets were passed to form solid images of each color.
[0084]
White streaks did not occur in any of the images after 24 hours and after passing 20000 sheets, and good images could be obtained. However, it was confirmed that the film scraping amount of the photosensitive drum after passing 20,000 sheets was 23 μm, and it was not possible to obtain a good image up to a predetermined life number.
[0085]
The results are shown in Table 1 below.
[0086]
Comparative Example 2
Development of four colors in the same manner as in Example 1 except that the amount of zinc stearate was changed to 2.1% cyan, 1.5% yellow, 1.5% magenta, and 0.01% black. An agent was obtained. Each developer was applied to each developing unit of the image forming apparatus having the same configuration as in FIG.
[0087]
The arrangement of each developing unit was set so that the angle formed by the regulating blade of the C developing unit with respect to the horizontal / vertical axis was 90 °. The Y developing unit was set to 210 ° and the M developing unit was set to 330 °.
[0088]
In this arrangement, the C developing unit is arranged at the bottom, and the metal soap content of the developer contained in the C developing unit is compared with the metal soap content of the developer contained in the Y and M developing units. The most.
[0089]
Thereafter, immediately after being left for 24 hours at room temperature and humidity, solid images of each color were formed.
[0090]
Thereafter, 20000 sheets were passed to form solid images of each color.
[0091]
The image immediately after being left for 24 hours contained two white streaks. This is presumably because zinc stearate aggregated in the vicinity of the developing sleeve. White lines were not generated in the image after passing 20,000 sheets, and a good image could be obtained. The film scraping amount of the photosensitive drum after passing 20,000 sheets was 17 μm, and it was confirmed that a good image was obtained up to a predetermined life number.
[0092]
The results are shown in Table 1 below.
[0093]
Example 5
Development of four colors in the same manner as in Example 1 except that the amount of zinc stearate was changed to 2.0% cyan, 10.1% yellow, 1.5% magenta, and 0.01% black. An agent was obtained.
[0094]
Each developer was applied to each developing unit of the image forming apparatus having the same configuration as in FIG.
[0095]
In this arrangement, the C developing unit is arranged at the bottom, and the metal soap content of the developer contained in the C developing unit is compared with the metal soap content of the developer contained in the Y and M developing units. , More than M and less than Y.
[0096]
The arrangement of each developing unit was the same as in Comparative Example 2. Thereafter, immediately after being left for 24 hours at room temperature and humidity, solid images of each color were formed.
[0097]
Thereafter, 20000 sheets were passed to form solid images of each color.
[0098]
The image immediately after being left for 24 hours had no white streaks. Three white streaks occurred in the image after passing 20,000 sheets, and a good image was not obtained. The film scraping amount of the photosensitive drum after passing 20,000 sheets was 14 μm, and it was confirmed that a good image was obtained up to a predetermined life number.
[0099]
The results are shown in Table 1 below.
[0100]
Example 6
Development of four colors in the same manner as in Example 1 except that the amount of zinc stearate was changed to 2.1% cyan, 10.1% yellow, 1.5% magenta, and 0.01% black. An agent was obtained.
[0101]
Each developer was applied to each developing unit of the image forming apparatus having the same configuration as in FIG.
[0102]
In this arrangement, the C developing unit is arranged at the bottom, and the metal soap content of the developer contained in the C developing unit is compared with the metal soap content of the developer contained in the Y and M developing units. , More than M and less than Y.
[0103]
The arrangement of each developing unit was the same as in Comparative Example 2. Thereafter, immediately after being left for 24 hours at room temperature and humidity, solid images of each color were formed.
[0104]
Thereafter, 20000 sheets were passed to form solid images of each color.
[0105]
Two white streaks occurred in the image immediately after being left for 24 hours, and a good image could not be obtained. This is presumably because zinc stearate aggregated in the vicinity of the developing sleeve. Furthermore, four white streaks were generated in the image obtained after passing 20,000 sheets, and a good image could not be obtained. This is presumably because a large amount of zinc stearate covered the developing sleeve, so that the force for transporting the developer decreased. The film scraping amount of the drum after passing 20,000 sheets was 13 μm, and it was confirmed that good images were obtained up to a predetermined life number.
[0106]
The results are shown in Table 1 below.
[0107]
[Table 1]

[0108]
As shown in Examples 1 to 4, in the apparatus to which the developer combination according to the present invention was applied, there was no white streaking even after being left for a long time, and there was little film abrasion on the photosensitive drum. Further, as shown in Examples 5 and 6, when the addition amount of the metal soap of the developer used in the second or third unit is more than 10 parts and the development used in the first unit When the amount of the metal soap added was more than 2 parts, some white streaks were observed. Further, as shown in Comparative Examples 1 and 2, when the amount of metal soap of the developer used in the first unit and the second or third unit is the same, the development used in the first unit. When the addition amount of the metallic soap as the agent is larger than the addition amount of the metallic soap as the developer used in the second or third unit, good results can be obtained with respect to generation of white stripes or film removal of the photosensitive drum. There wasn't.
[0109]
【The invention's effect】
According to the present invention, it is possible to prevent the metal soap from sticking to the blade surface and to prevent the image carrier from being scraped off and form a good image.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating an example of an image forming apparatus of the present invention.
FIG. 2 is a diagram illustrating an example of a positional relationship between a developing sleeve and a blade
FIG. 3 is a diagram illustrating an example of a positional relationship between a developing sleeve and a blade.
FIG. 4 is a diagram illustrating an example of a positional relationship between a developing sleeve and a blade
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 7 ... Intermediate transfer belt mechanism, 7a ... Belt, 11B ... Black developing unit, 9 ... Fixing device, 12 ... Revolver, 12Y, 12M, 12C ... Developing unit, 13 ... Rotating developing device, 14 ... Photosensitive Drum, 21Y, 21M, 21C ... blade, 22Y, 22M, 22C ... developing sleeve

Claims (7)

A rotatable developer carrying member for supplying the developer to the photoreceptor, and the thickness of the developer layer disposed on the surface of the developer carrying member and supported on the surface of the developer carrying member. An image forming apparatus having a rotary developer having two or more developing units each having a blade for regulating the thickness and containing developers of different colors,
Against the direction of rotation of said developer carrying member at the time of stopping the rotary developing device, the blade surface located upstream from the position facing the said blade and said developer carrying member, in the rotating direction with respect to the vertical axis along angle formed by the developing unit is 135 degrees from 45 degrees first developing unit, against the rotation direction of the developer carrying member, positioned upstream from the position facing the said blade and said developer carrying member When the developing unit whose blade surface has an angle along the rotation direction with respect to the vertical axis other than 45 degrees to 135 degrees is defined as the second developing unit,
The second developer contained in the second developing unit includes a toner containing a colorant, a binder resin, and a metal soap,
The first developer contained in the first developing unit contains a metal soap in an amount less than the amount of the metal soap contained in the colorant, the binder resin and the second developer, or does not contain the metal soap. An image forming apparatus comprising a toner.   A developer selected from a yellow developer, a magenta developer, and a cyan developer is applied to the developing unit of the rotary developer, and a black developer is applied independently of the rotary developer. The image forming apparatus according to claim 1, further comprising a black developing unit to be accommodated.   The image forming apparatus according to claim 2, wherein the black developer contains a larger amount of metal soap than that of the first developer.   The rotary developer further includes a third developer unit that is above the first developer unit when the rotary developer is stopped, and the third developer accommodated in the third developer unit is 4. The image forming apparatus according to claim 1, further comprising: a toner containing a metal soap in an amount greater than the metal soap content of the colorant, the binder resin, and the first developer. .   5. The image according to claim 1, wherein the amount of the metal soap contained in the first developer is 0 or more and 2% by weight or less based on the total toner weight. Forming equipment.   6. The image forming apparatus according to claim 1, wherein an amount of the metal soap contained in the second developer is greater than 0 and equal to or less than 10% by weight with respect to the total weight of the toner. . A rotatable developer carrying member for supplying the developer to the photoreceptor, and the thickness of the developer layer disposed on the surface of the developer carrying member and supported on the surface of the developer carrying member. A combination of developers respectively applied to each developing unit of a rotary developing device provided with two or more developing units having blades for regulating the thickness,
Against the direction of rotation of said developer carrying member at the time of stopping the rotary developing device, the blade surface located upstream from the position facing the said blade and said developer carrying member, in the rotating direction with respect to the vertical axis along angle formed by the developing unit is 135 degrees from 45 degrees first developing unit, against the rotation direction of the developer carrying member, positioned upstream from the position facing the said blade and said developer carrying member When the developing unit whose blade surface has an angle along the rotation direction with respect to the vertical axis other than 45 degrees to 135 degrees is defined as the second developing unit,
More than the amount of the metal developer contained in the second developer unit and containing the toner containing the colorant, the binder resin and the metal soap, and the metal soap contained in the colorant, the binder resin and the second developer. A combination with a first developer containing a toner containing a small amount of metal soap or no metal soap.

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