JP2003186251A - Electrophotographic magenta toner, developer and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide electrophotographic magenta toners which excel in a flow property and uniform dispersibility of coloring agents, do not give rise to surface contamination and scattering of toners, reduces the occurrence of filming and spent toners to carriers, do not admit image defects, have excellent transparency, colorability and color reproducibility, and make it possible to obtain image quality stable for a long period, a developer and an image forming device. <P>SOLUTION: The electrophotographic magenta toners in which a binder resin is a polyester resin and/or polyol resin; a magenta coloring agent is, for example, C.I. Pigment Red 57:1; a charge control agent is a resin charge control agent consisting of (a) a sulfonic acid base-containing monomer, (b) an aromatic monomer containing an electron attractive group, (c) an acrylate monomer and/or methacrylate monomer, and (d) an aromatic vinyl monomer or the described above (a), (b) and (c) as constitutional units; additives are at least silica and/or titania; and the rate of liberation of the additives is 0.3 to 4%. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magenta toner for electrophotography, a developer and an image forming apparatus which are applied to electrophotography, electrostatic recording, electrostatic printing and the like.

[0002]

2. Description of the Related Art As a conventional electrophotographic method, US Pat.
Although various methods are described in Japanese Patent No. 7691, Japanese Patent Publication No. 42-23910, Japanese Patent Publication No. 43-24748, etc., generally, a photoconductive substance is used and the photoconductive support is formed by various means. An electrical latent image is formed on the body, and then the latent image is developed with toner to obtain a visible image, or a powder image is transferred to paper or the like, if necessary, and then heating / pressurizing or solvent vapor is applied. It is fixed by a method such as the above to obtain a visible image. Further, as a full-color electrophotographic method for obtaining a multicolor image of color, as described in U.S. Pat. No. 2,962,374, at least the images are blue, green and red.
The color signals of the colors are separated and exposed, and the above steps are repeatedly developed a plurality of times using at least process color toners such as yellow, magenta, and cyan, and the toner images are superimposed to obtain a multicolor image of color. is there.

In recent years, the hard copy technique using the electrophotographic system has been rapidly developed from black and white to full color, and the full color market is expanding rapidly. Color image formation by full color electrophotography generally reproduces all colors by using three color toners of three primary colors, yellow, magenta, and cyan, or four colors including black. The general method is to first form an electrostatic latent image on the photoconductive layer by passing light from the original through a color separation light transmitting filter having a complementary color relationship with the color of the toner.
Next, the toner is held on the support through a development and transfer process. Then, the above-mentioned steps are sequentially carried out a plurality of times to superimpose the toner on the same support while matching the registration, and the final full-color image is obtained by fixing only once. Such multiple development,
In full-color electrophotography, which requires superposition of several types of toner images of different colors on the same support, the fixing characteristics that color toners must have are extremely important factors.
That is, the fixed color toner is required to suppress diffused reflection due to toner particles as much as possible, have an appropriate glossiness and gloss, and have transparency that does not interfere with toner layers having different tones below the toner layer. The color toner should have wide color reproducibility.

Here, a color toner is generally produced by melt-kneading a binder resin, a colorant and, if necessary, other materials such as a charge control agent, and further pulverizing the mixture to classify it into a predetermined particle size. ing. As the colorant for these color toners, an organic pigment-based colorant, which is superior to the dye-based colorant in terms of light resistance and safety, is generally used.

Further, as a colorant for magenta toner, C.I. I. Pigment Red 57: 1, which is a soluble azo pigment, has a relatively high degree of coloring, is excellent in transparency, and is inexpensive, and thus is widely used.

However, since these organic pigment-based colorants form an aggregate of primary particles,
With the method of melt-kneading a binder resin, a colorant, and if necessary, other materials such as a charge control agent, which is a conventional method for producing a color toner, it is not possible to solve the strong aggregation state of the colorant. Therefore, it is difficult for the colorant to be uniformly dispersed in the binder resin, and the primary particles of the pigment exist as aggregates in the toner. Therefore, the transparency, which is one of the most important characteristics of the color toner, is greatly deteriorated, the color reproducibility and the light transmissivity of the OHP film are greatly reduced, and a sufficient coloring degree cannot be obtained. In particular, this tendency is remarkable in the color toner having a small particle diameter.

Here, for the toner having a low coloring degree, it is necessary to increase the adhesion amount of the toner at the time of development. Especially, in outputting a full-color image, it is necessary to overlap the toners of at least two colors, and the adhesion amount is increased accordingly. Because there are many
Further, the transparency tends to deteriorate and the color reproducibility tends to deteriorate.

Further, the toner having a low degree of coloring increases the amount of toner consumed, especially in the development of solid areas.
It is necessary to frequently replenish toner in the developing unit,
As a result, in the case of a two-component developer, it is difficult to uniformly agitate the toner and carrier in the developing device, and scumming is likely to occur, and uneven transfer and white spots occur when a solid image is output. Image defects are likely to occur, and it is difficult to obtain a uniform solid image.

Further, if the amount of toner adhered is increased, toner dust is likely to occur in the fine line portion, and particularly in the case of outputting fine lines in a full-color image, it is necessary to overlap toners of at least two colors, This tendency is particularly remarkable because the amount of adhesion is further increased.

Therefore, in order to solve such a problem, JP-A-62-30259 and JP-A-62-280755 are used.
JP-A-2-66561 and JP-A-2-293866.
JP-A-2-293867, etc., there has been proposed a method for improving the dispersion of an organic pigment in a toner by using a processed pigment usually called a masterbatch. The processed pigments described in these publications are prepared by first heat-melting and kneading a dry organic pigment with a binder resin so that the organic pigment has a higher concentration than a usual pigment concentration used in a toner, and further, a pigment concentration suitable as a toner is obtained. Is manufactured by diluting, melting and kneading using a binder resin. However, these organic pigment-based colorants form aggregated particles in which primary particles are gathered, and these aggregated particles do not affect the light transmittance of the toner even if the above-described method is used. It is difficult to finely disperse.

As another method, for example, a method of dissolving the raw materials in a solvent, mixing them, and then evaporating the solvent to prepare a masterbatch is disclosed in JP-A-61-117595 and JP-A-61-160554. Although stated,
Just stirring the mixture in solution does not apply sufficient shearing force, and thus the colorant is insufficiently dispersed.

Further, in JP-A-62-127847, an aqueous dispersion of fine particle phthalocyanine pigment obtained by an acid paste method or an acid slurry method is directly dried into a solution of a binder resin and an organic solvent without being dried. By mixing, it is said that phthalocyanine can be uniformly dispersed in the binder resin in the form of fine particles, but in this method, it is necessary to use a large amount of an organic solvent to dissolve the binder resin, Further, there is a problem that the pigment is likely to re-aggregate when removing water or the organic solvent.

Further, in JP-A-7-311479, a pigment-dispersed resin obtained by mixing a water-containing paste of a pigment into a pigment-dispersing resin solution and then heat-treating it is used. It is said that by using an incompatible resin having an SP value difference with the binder resin, the transparency, offset resistance, and wrapping resistance are excellent, but the binder resin and the resin in which the pigment is dispersed are compatible with each other. Since different resins are used, the refractive index becomes high, and sufficient transparency cannot be obtained.

In the case of the color toner, since gloss and transparency are required as compared with the black toner, it is general to use a resin having a low melting sharp melting property,
The shearing applied at the time of kneading is much lower, and even if the above-mentioned processed pigment in which the pigment and the binder resin are dispersed in advance is used, an aggregate of the pigment is inevitably present. I. Pigm
When a soluble azo pigment represented by ent Red 57: 1 is used, aggregates may be present in the toner in the form of aggregates, and these aggregates are detached from the magenta toner surface, This causes factors such as background stains, toner scattering, and filming on the photoconductor.

Even if these agglomerates are not detached from the toner surface, C.I. I. Pigment Red
Since the soluble azo pigment represented by 57: 1 generally has low chargeability, a toner containing a large amount of these agglomerates or agglomerates in the same toner is obviously inferior in chargeability. Since it also becomes broad, it leads to an increase in background stains and toner scattering.Furthermore, filming on the photoconductor and the like, and in the case of a two-component developer, spent on the carrier are also likely to occur, and moreover, transfer unevenness and It was also a cause of image defects such as white spots.

Further, conventionally, a charge control agent has been added in order to stabilize the charge of the toner. The charge control agent controls the triboelectric charge amount of the toner and maintains the triboelectric charge amount. Typical negative charge control agents include monoazo dyes, salicylic acid, naphthoic acid, metal salts / complexes of dicarboxylic acids, diazo compounds, complex compounds of boron, and the like. Examples of the control agent include quaternary ammonium salt compounds, imidazole compounds, nigrosine, and azine dyes. However, since these charge control agents are colored, there is a problem that the hue changes when used for color toner. Further, since such a charge control agent has a poor compatibility with the binder resin, it is easy to detach what is present on the toner surface, which is greatly involved in charging,
There are drawbacks such that variations in toner charge, development sleeves, and photoreceptor filming easily occur. Therefore, in the past, a good image was obtained in the initial stage, but there was a phenomenon that the image quality gradually changed and scumming and blurring occurred, especially when applied to color copying and continuously used while supplying toner. , The charge amount of the toner has decreased, and the color tone of the initial copy image is markedly different, and it cannot withstand long-term use, and an imaging unit called a process cartridge is replaced early after several thousand sheets. It had drawbacks such as being necessary. Therefore, the load on the environment is large and the user's time and effort are taken. Further, since many of these contain heavy metals such as chromium, they are becoming a problem in terms of safety in recent years.

Therefore, as means for improving the above problems, Japanese Patent Laid-Open Nos. 63-88564 and 63-18476.
No. 2, JP-A-3-56974, JP-A-6-2.
Japanese Patent No. 30609 discloses a resin charge control agent having improved compatibility with a binder resin, transparency of a toner-fixed image, and safety. Since these resin charge control agents have good compatibility with the binder resin, they are excellent in stable chargeability and transparency. However, these resin charge control agents are monoazo dyes,
Compared with a toner using a metal salt / metal complex salt of salicylic acid, naphthoic acid, or dicarboxylic acid, there is a drawback in that the charge amount and the charge speed are inferior. Further, although the chargeability is improved by increasing the addition amount of the resin charge control agent, it adversely affects the toner fixability (low temperature fixability, offset resistance). Furthermore, these compounds have low environmental stability (moisture resistance) in the amount of charge. Therefore, there is also a problem that scumming is likely to occur.

Therefore, again, Japanese Patent Laid-Open Nos. 8-30017, 9-171271, and 9-211.
In Japanese Laid-Open Patent Publication No. 896 and Japanese Patent Laid-Open No. 11-218965,
A copolymer of a monomer containing an organic acid salt such as a sulfonate group and an aromatic monomer having an electron-withdrawing group has been proposed. However, due to the hygroscopicity and adhesiveness that are thought to be due to the monomer containing an organic acid salt such as a sulfonate group, a sufficient charge amount is secured, but the dispersion in the binder resin is not sufficient,
The effect of suppressing the variation in the charging of the toner for a long time and preventing the developing sleeve, the photoconductor filming, and the like are not sufficient. The volatile content of the binder resin for toner obtained by a known polymerization method such as solution polymerization or bulk polymerization is usually 0.5 to 2.0% by mass in the devolatilization step. The amount of water and the polymerization solvent, which are considered to be derived from the monomer containing an organic acid salt such as sulfonate group, remains, and the amount of volatile components increases. Therefore, there is a problem in handling such as a problem in storage stability of the resin charge control agent itself, agglomeration when the materials before kneading are left to stand after pre-mixing, and powder cannot be transported. In addition, the dispersion in the binder resin is not sufficient,
The effect of suppressing the variation in the charging of the toner for a long time and preventing the developing sleeve, the photoconductor filming, and the like are not sufficient. Further, in terms of manufacturability in the pulverizing method of the toner, monoazo dyes, salicylic acid, naphthoic acid, and metal salts / complexes of dicarboxylic acids are used as the charge control agent because they adhere to various parts in the pulverizer and the pulverization amount per unit time is small. There was also an adverse effect that productivity was lower than when used.

Further, in order to further improve the compatibility with the binder resin such as styrene resin or polyester resin, a monomer containing an organic acid salt such as a sulfonate group and an aromatic monomer having an electron-withdrawing group are combined with each other. A copolymer with a styrene-based monomer when the binder resin is a styrene-based resin and a polyester-based monomer when the binder resin is a polyester-based resin is also proposed, but it is possible to maintain the charge amount for a long period of time and to The effect of preventing photoconductor filming is not sufficient.
In particular, as a binder resin for color toner, it is insufficient for a polyester resin and a polyol resin which are suitable in terms of color developability and image strength.

Further, in recent years, the demand for printers has expanded, and the downsizing, speeding up, and cost reduction of devices have progressed, and higher reliability and longer service life have begun to be demanded for the devices, and various characteristics of toners have long-term characteristics. However, these resin charge control agents cannot maintain the charge control effect, and the developing sleeve and the layer thickness regulating member (blade and roller) are contaminated and the toner charging performance is deteriorated. However, there is a problem in that filming of the photoconductor is likely to occur.

[0021]

The object of the present invention is to solve the above-mentioned problems in the prior art, and in particular, it has excellent fluidity and uniform dispersibility of the magenta colorant, and does not cause scumming or toner scattering. There is little filming on the photoconductor or the like, and in the case of a two-component developer, the occurrence of spent on the carrier is small, and image defects such as transfer unevenness and white spots are not seen, and the transparency and the degree of coloring are high. And a magenta toner for electrophotography, a developer, and an image forming apparatus capable of obtaining stable image quality for a long time even when a toner having a small particle diameter is used, in addition to being excellent in color reproducibility. To do.

[0022]

SUMMARY OF THE INVENTION The present invention provides a magenta toner for electrophotography, which is obtained by adding an additive to toner particles containing at least a binder resin, a magenta colorant, and a charge control agent. , A polyester resin and / or a polyol resin, the magenta colorant is a compound represented by the following general formula (I), and the charge control agent is
(A) a sulfonate group-containing monomer, (b) an aromatic monomer having an electron-withdrawing group, (c) an acrylic acid ester monomer and / or a methacrylic acid ester monomer, and (d) an aromatic vinyl monomer, or the above ( a),
A resin charge control agent having (b) and (c) as constitutional units, wherein the additive is at least silica and / or titania, and the release rate of the additive of the toner is 0.3.
It relates to a magenta toner for electrophotography, which is characterized in that it is ˜4%.

[0023]

[Chemical 2] (In the formula, R ¹ and R ² may be the same or different,
At least one selected from the group consisting of hydrogen atom, alkyl group, phenyl group and halogen atom, and M is B
It is one of a, Ca, Sr, Mn, and Mg. )

Here, the compound represented by the general formula (I) is C.I. I. Pigment Red 57: 1, which is a soluble azo pigment, has a relatively high degree of coloring among magenta pigments, excellent transparency, and is inexpensive, and thus is a general-purpose colorant for magenta toners. Is used for.

Further, in general, the organic pigment-based colorant represented by the general formula (I) forms an agglomerate of primary particles, so that the binder resin and the colorant, which are the usual toner manufacturing methods, are used. And, by a method of melt-kneading another material such as a charge control agent as necessary, since the strong aggregation state of this colorant cannot be released, it is difficult for the colorant to be uniformly dispersed in the binder resin. The primary particles of the pigment are present as aggregates therein. Therefore, it is widely practiced to improve the dispersibility of the pigment at the time of melt-kneading by preparing a processed pigment usually called a masterbatch in which the pigment and the binder resin are dispersed in advance.

However, in the case of the color toner, glossiness and transparency are required as compared with the black toner, and therefore it is general to use a resin having a low melting sharp melt property,
The shearing applied during kneading is much lower, and even if a resin in which a pigment is previously dispersed, such as a processed pigment, is used, aggregates of the pigment are inevitably present. In particular, the compound represented by the general formula (I) was used. In this case, the aggregates may be present in the toner in the form of agglomerates, and these agglomerates are detached from the magenta toner surface, causing scumming, toner scattering, and filming on the photoconductor. It was a factor such as.

Even when these agglomerates are not detached from the toner surface, the compound represented by the general formula (I) has a low chargeability, and therefore the same toner contains a large amount of these agglomerates and agglomerates. Toner obviously has poor chargeability,
As a result, the charging of the entire toner becomes broad,
In addition to causing scumming and toner scattering, filming on the photoconductor, and in the case of a two-component developer, spent on the carrier are also likely to occur. In addition, image defects such as uneven transfer and white spots occur. Was also the cause.

On the other hand, as a result of intensive studies, the present inventors have used a polyester resin and / or a polyol resin as a binder resin, and (a) a sulfonate group-containing monomer (b) as a charge control agent. ) An aromatic monomer having an electron-withdrawing group, (c) an acrylic acid ester monomer and / or a methacrylic acid ester monomer, and (d) an aromatic vinyl monomer, or (a), (b), and (c) above.
Is used as a constitutional unit, at least silica and / or titania is used as an additive, and the release rate of the additive of the toner is set to 0.3 to 4% to obtain fluidity and magenta. Excellent in uniform dispersibility of the colorant, scumming and toner scattering do not occur, and further, filming on the photoreceptor or the like, in the case of a two-component developer, the occurrence of spent on the carrier is small, and further, No image defects such as transfer unevenness or white spots are seen, and the transparency, coloring degree, and color reproducibility are further excellent.In addition, stable image quality can be obtained for a long period of time even when a toner having a small particle size is used. The inventors have found that they can be obtained and have completed the present invention.

In the toner using the compound represented by the general formula (I) as the colorant, a polyester resin and / or a polyol resin is used as the binder resin, and the (a) sulfonic acid is used as the charge control agent. A base-containing monomer, (b) an aromatic monomer having an electron-withdrawing group, (c) an acrylic acid ester monomer and / or a methacrylic acid ester monomer, and (d) an aromatic vinyl monomer, or (a), (b) above. ), And (c) as a constitutional unit, a magenta toner in which at least silica and / or titania is used as an additive, and the additive release rate of the toner satisfies a certain range. , Did not exist until now.

Here, a polyester resin and / or a polyol resin is used as the binder resin, (a) a sulfonate group-containing monomer, (b) an aromatic monomer having an electron-withdrawing group, and (c) acrylic acid as a charge control agent. By using an ester monomer and / or a methacrylic acid ester monomer, and (d) an aromatic vinyl monomer, or a resin charge control agent containing (a), (b), and (c) as a constitutional unit, When the dispersibility of the compound represented by the formula (I) in the resin is improved, stable chargeability is obtained, and further, transparency and color reproducibility are further excellent, and when a toner having a small particle size is used, It was revealed that stable image quality can be obtained over a long period of time.

The reason for this is not clear at this point, but
Since the compound represented by the general formula (I) is a soluble azo pigment and has a carboxyl group or a sulfonic acid group, the compound represented by the general formula (I) is represented by the interaction with the carboxyl group or the hydroxyl group in the polyester resin or the polyol resin. It is considered that an extremely high effect was obtained on the dispersibility of the compound shown.

Further, since the acid value of the polyester resin and / or the polyol resin at this time is 20 KOHmg / g or less, the charge amount increases under low temperature and low humidity, and the charge amount decreases under high temperature and high humidity. No charge was observed, charge stability was good, stable image quality was obtained for a long period of time, and dispersibility of the compound represented by the general formula (I) was good.

Further, the combined use of (a) a sulfonate group-containing monomer and (b) an aromatic monomer having an electron-withdrawing group as the monomer constituting the resin charge control agent enhances the charge imparting effect. By using the (c) acrylic acid ester and / or methacrylic acid ester monomer, the environmental stability of charging is further improved, and at this time, (a) the sulfonic acid group contained in the sulfonic acid group-containing monomer, or ( c) A carbonyl group or an alkoxyl group of an acrylic acid ester and / or a methacrylic acid ester, a carboxyl group or a hydroxyl group in a polyester resin or a polyol resin, and a carboxyl group or a sulfone of a compound represented by the general formula (I). Due to the interaction with the acid group, the compound of the general formula (I) or the charge control agent is bound. Dispersibility is further improved with respect to the resin, furthermore, it is considered that an extremely high effect was obtained for the chargeability.

Since the resin charge control agent was white, the transparency and color reproducibility were also good at this time.

Further, at this time, at least silica and / or titania is used as an additive, and the release rate of the additive of the magenta toner is 0.3 to 4%, preferably 0.5 to 2%.
Therefore, it is excellent in fluidity, does not cause scumming and toner scattering, and further, filming on a photoreceptor or the like by a magenta colorant or an additive, or a carrier in the case of a two-component developer. There are few occurrences of spent, etc., and on top of that, image defects such as transfer unevenness and white spots are not seen, and further, transparency, coloring degree and color reproducibility are further excellent,
In addition, it was revealed that stable image quality can be obtained for a long period of time even when a toner having a small particle size is used.

This is because by using silica and / or titania as an additive, it is possible to obtain excellent chargeability, environmental stability and the like, and by using silica and titania together, it is possible to obtain appropriate fluidity. Also, under high temperature and high humidity, while maintaining the charge amount of toner required for development,
The charge uniformity on the surface of toner particles and the charge exchange property between toner particles can be accelerated, the charging speed can be improved, and the distribution of charge can be sharpened. It is thought that this is because of the significant improvement.

At this time, by further setting the release rate of the additive of the magenta toner to 0.3 to 4%, preferably 0.5 to 2%, the released additive can be reduced. Since the uniform adhesion of the additive to the toner particles at this time is also improved, it is possible to uniformly coat the magenta colorant having low chargeability exposed on the surface with the additive. It is considered that the above results improved the fluidity and obtained a high effect on the background stain, the toner scattering, and the filming of the photoconductor or the like by the magenta colorant or the additive.

When the release rate of the additive exceeds 4%, the released additive adheres to the image bearing member such as the photoconductor or the developing roller and causes the development failure such as filming or cleaning failure. It is easy to become. Further, the liberated additive easily contaminates the surface of the carrier, particularly in the case of a two-component developer, and reduces the charge imparting ability of the carrier itself. It is easy to cause. Further, in the toner in which the additive is released, the additive amount of the additive decreases with time, and the uniform adhesion of the additive to the toner particles also decreases, so that the magenta colorant exposed on the surface is evenly distributed in the additive. Can no longer be covered. In addition, the fusing property between toners also increases,
Therefore, agglomeration is likely to occur, fluidity is lowered, and
Filming on an image bearing member such as a photoconductor is also likely to occur, and durability is likely to decrease. This tendency is remarkable especially under high temperature and high humidity.

When the release rate of the additive is less than 0.3%, the additive adheres strongly to the toner particles and is easily embedded in the surface of the toner particles, so that aggregation easily occurs and sufficient fluidity is obtained. I can't get it.

By setting the release rate of the additive within the range of 0.3 to 4%, preferably 0.5 to 2%, the filming on the photosensitive member, the developing roller, etc. and the adhesion to the carrier can be prevented. Since it does not occur and there is little decrease in additives and increase in aggregates over time, the fluidity is excellent and the durability can be greatly improved.

Here, the release rate of the additive can be measured by various methods. In the present invention, PT100 is used.
It was calculated by the following equation using 0 (manufactured by Yokogawa Electric Corporation). Additive release rate

[0042]

[Equation 1] I ¹ : Count number of additive element that did not emit light at the same time as C element I ² : Count number of additive element that did not emit light at the same time as C element

The measurement conditions at this time are shown below in the case of using silica and titania as additives. Analysis wavelength: Si element: 288.160 nm Ti element: 334.900 nm C element: 247.860 nm Spectrometer used: Si element: No. 1 or No. 2 (Blazing wavelength: 25
0 nm) Ti element: No. 1 or No. 2 (Blazing wavelength: 25
0 nm) C element: No. 3 or No. 4 (Blazing wavelength: 40
0 nm) Measurement gas: O ₂ 0.1% He gas C element detection number per scan: 500 to 1000 Noise cut level: 1.5 or less Sort time: 30 digits

Here, the main component of the C element is toner particles, and even when an additive surface-treated with a silane coupling agent or the like is used, the substantial addition amount of the silane coupling agent is large. Since it is about several parts by mass, and the amount of C element detected by the silane coupling agent or the like is almost smaller than that of the toner particles, the release rate of the additive can be obtained by the above formula.

When two or more different types of additives were used, the average release rate of all additives was calculated from the release rate of each additive and the amount added at that time.

The amount of the additive added at this time is preferably 2.5 to 4.0 parts by mass, and particularly preferably 3.0 to 3.5 parts by mass, relative to 100 parts by mass of the toner particles. Is. If the amount added is less than 2.5 parts by mass, the fluidity and chargeability of the toner tend to decrease, and the magenta colorant with low chargeability exposed on the toner particle surface is sufficient as an additive. It is not possible to coat on the surface of the photoconductor, and scumming and toner scattering easily occur. Furthermore, filming on the photoconductor and the like, and in the case of a two-component developer, the occurrence of spent on the carrier and the like are seen. Uneven transfer and white spots,
Furthermore, image defects such as voids in the transfer in thin line portions are likely to occur. If the amount is more than 4.0 parts by mass, the fluidity is improved, but the cleaning of the photosensitive member such as chattering or blade curling is not likely to occur, and the filming on the photosensitive member due to the additive released from the toner is likely to occur. The durability of the blade, the photoconductor, etc. is reduced. Further, toner dust is easily generated in a fine line portion called transfer dust, and this tendency becomes more noticeable particularly when two or more color toners are superposed and developed as in a color fine line.

There are various methods for measuring the additive amount of the additive, but the fluorescent X-ray analysis method is generally used. That is, for the toner whose additive amount is known,
A calibration curve was prepared by the fluorescent X-ray analysis method, and the addition amount of the additive was determined using this calibration curve.

Further, the average primary particle size of the additive used in the present invention is 0.002 to 2 from the viewpoint of imparting fluidity.
The thickness is preferably 0.03 μm, and particularly preferably 0.005 to 0.02 μm. When the average primary particle diameter of the additive is smaller than 0.002 μm, the additive is easily embedded in the toner particle surface, which easily causes aggregation and cannot obtain sufficient fluidity. This tendency is more remarkable when used for a color toner having a sharp melt property. Further, filming on an image bearing member such as a photoconductor is likely to occur, and these tendencies are particularly remarkable under high temperature and high humidity. In addition, if the average primary particle size of the additive is smaller than 0.002 μm, the additives tend to coagulate with each other, and this also makes it difficult to obtain sufficient fluidity. Further, if the average primary particle diameter of the additive is larger than 0.03 μm, the fluidity of the toner is lowered, so that sufficient chargeability cannot be obtained, which easily causes scumming and toner scattering. It is easy to damage the surface of the image carrier such as, and it is also likely to cause filming. Here, the particle size of the additive was measured by a transmission electron microscope.

Further, it is preferable that the additives used in the toner of the present invention are subjected to surface treatment, if necessary, for the purpose of hydrophobizing, improving fluidity, controlling chargeability and the like. Here, the treatment agent used for the surface treatment is preferably an organic silane compound or the like, for example, methyltrichlorosilane,
Examples thereof include alkylchlorosilanes such as octyltrichlorosilane and dimethyldichlorosilane, alkylmethoxysilanes such as dimethyldimethoxysilane and octyltrimethoxysilane, hexamethyldisilazane, and silicone oil. Further, as the treatment method, there are a method of immersing the additive in a solution containing an organic silane compound and drying, a method of spraying a solution containing the organic silane compound as an additive and drying, but in the present invention, Any of these methods can be preferably used.

The toner of the present invention may further contain other additives in addition to the above additives. Examples of such additives include Al, Mg, Ca, S
r, Ba, In, Ga, Ni, Mn, W, Fe, Co,
Oxides and complex oxides of Zn, Cr, Mo, Cu, Ag, V, Zr, etc., and Teflon (registered trademark), zinc stearate, polyvinylidene fluoride, etc. as lubricants,
As an abrasive, cerium oxide, silicon carbide, strontium titanate, etc., as a conductivity imparting agent, carbon black, zinc oxide, antimony oxide, tin oxide, etc.,
Each is listed.

Further, in the magenta toner of the present invention, the charge control agent is (a) a sulfonate group-containing monomer, (b)
An aromatic monomer having an electron-withdrawing group, (c) an acrylic acid ester monomer and / or a methacrylic acid ester monomer, and (d) an aromatic vinyl monomer, or (a), (b), or (c) is constituted. It is a resin charge control agent as a unit.

Examples of the (a) sulfonate group-containing monomer constituting the resin charge control agent used in the present invention include an aliphatic sulfonate group-containing monomer and an aromatic sulfonate group-containing monomer.

Examples of the aliphatic sulfonate group-containing monomer include vinyl sulfonic acid, allyl vinyl sulfonic acid, 2-
Examples thereof include alkali metal salts such as acrylamido-2-methylpropanesulfonic acid and methacryloyloxyethylsulfonic acid, alkaline earth metal salts, amine salts and quaternary ammonium salts.

Examples of the aromatic sulfonate group-containing monomer include styrene sulfonic acid, sulfophenylacrylamide, sulfophenylmaleimide, sulfophenylitaconimide and other alkali metal salts, alkaline earth metal salts, amine salts and quaternary ammonium salts. Is mentioned.
Heavy metal salts (nickel, copper, zinc, mercury, chromium, etc.) are not preferable in terms of safety.

(B) Examples of aromatic monomers having an electron-withdrawing group include chlorostyrene, dichlorostyrene, bromostyrene, fluorostyrene, nitrostyrene, styrene substitution products such as cyanstyrene, and chlorophenyl (meth).
Acrylate, bromophenyl (meth) acrylate,
Phenyl (meth) acrylate substitution products such as nitrophenyl (meth) acrylate and chlorophenyloxyethyl (meth) acrylate, chlorophenyl (meth) acrylamide, bromophenyl (meth) acrylamide,
Phenyl (meth) acrylamide substitution products such as nitrophenyl (meth) acrylamide, chlorophenylmaleimide, dichlorophenylmaleimide, nitrophenylmaleimide, phenylmaleimide substitution products such as nitrochlorophenylmaleimide, chlorophenylitaconimide,
Examples thereof include phenylitaconimide substitution products such as dichlorophenylitaconimide, nitrophenylitaconimide and nitrochlorophenylitaconimide, and phenyl vinyl ether substitution products such as chlorophenyl vinyl ether and nitrophenyl vinyl ether. Particularly, a phenylmaleimide-substituted product and a phenylitaconimide-substituted product substituted with a chlorine atom or a nitro group are preferable in terms of charging property and filming resistance.

(C) Acrylic ester monomer and /
Alternatively, as the methacrylic acid ester monomer, methyl (meth) acrylate, ethyl (meth) acrylate,
Propyl (meth) acrylate, n- (meth) acrylic acid
Examples include butyl, isobutyl (meth) acrylate, stearyl (meth) acrylate, dodecyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate.

Examples of the aromatic vinyl monomer (d) include styrene, vinyltoluene and α-methylstyrene.

By adding a sulfonic acid group-containing monomer as a monomer constituting the resin charge control agent used in the present invention, the charge imparting effect of the resin charge control agent is improved, but the environmental stability of the toner is improved due to its hygroscopicity. It is generally known to be used as a copolymer with an aromatic monomer having an electron-withdrawing group, etc., since the property (temperature and humidity stability) is reduced, but it may be used for about several thousand sheets, For long-term use of more than one sheet, the developing sleeve and layer thickness control members (blades and rollers) may be contaminated and the photoconductor filming may occur, resulting in insufficient charge stability of toner and maintenance of high image quality. There is a problem that the sex is also reduced. In order to make up for such drawbacks, (a) a sulfonic acid group-containing monomer, (b) is used as a binder resin for a color toner, in contrast to a polyester resin or a polyol resin suitable in terms of color developability and image strength.
An aromatic monomer having an electron-withdrawing group, (c) an acrylic acid ester and / or a methacrylic acid ester monomer,
And (d) by using a copolymer containing four kinds of aromatic vinyl monomers or three kinds of monomers (a), (b), and (c) as a resin charge control agent,
Long-term charging, excellent environmental stability, no contamination of the developing sleeve or layer thickness control member (blade or roller), good toner thin layer formation, photoconductor filming prevention,
An electrophotographic toner having high image quality and high productivity can be obtained.

It is presumed that these effects are due to the following reasons. That is, the combined use of (a) a sulfonate group-containing monomer and (b) an aromatic monomer having an electron-withdrawing group enhances the charge imparting effect,
(C) By using an acrylic acid ester monomer and / or a methacrylic acid ester monomer, the environmental stability of charging is further increased and the resin hardness is increased,
The pulverizability is improved, the developing sleeve and the layer thickness regulating member (blade and roller) are not contaminated, and the photoconductor filming prevention effect is improved. Further, by combining it with a polyester resin or a polyol resin, which is suitable as a binder resin for color toners in terms of color developability and image strength, a suitable dispersibility can be obtained, and a magenta toner for electrophotography having a sharp charge distribution can be obtained.

The resin charge control agent used in the present invention has (b) a volume resistance which is considered to be caused by residues such as a catalyst, a polymerization inhibitor and a solvent at the time of synthesizing an aromatic monomer having an electron-withdrawing group. Variation may occur and affect the desired charge amount of the toner. Therefore, problems such as rising of the charge of the toner containing the resin charge control agent and charge-up of the saturated charge amount may occur.

From this point of view, the volume resistance of the resin charge control agent used in the present invention is 9.5 to 11.5 LogΩ · c.
m is preferable, and more preferably 10.0 to 11.0 Lo.
It is gΩ · cm. The volume resistance of the resin charge control agent is 9.5.
If it is less than Log Ω · cm, the toner on the developing roller cannot initially obtain a desired charge amount, and scumming and toner scattering occur. On the other hand, when the volume resistance of the resin charge control agent exceeds 11.5 LogΩ · cm, the toner on the developing roller initially obtains a desired charge amount, but the toner is charged up over time, and in the one-component developing method. The thin toner layer on the developing roller is not uniform, and color streaks appear on the image.
In the two-component development method, unevenness occurs, image density is lowered, and background stains, toner scattering, and the like occur.

Here, the volume resistance of the resin charge control agent was measured by the following method. For example, 3 g of resin powder that has been sized using a sieve or the like is pressed at about 500 kgf / cm ² and molded into pellets having an area of 12.5 cm ² and a thickness of 1.8 to 2.2 mm. Frequency 1 using a derivative loss measuring instrument (TR-10C type manufactured by Ando Electric Co., Ltd.)
The measurement was performed in the state where kHz was applied, and the volume resistance was calculated from this.

The composition ratio of the monomer in the resin charge control agent used in the present invention is preferably 1 to 30% by mass, more preferably 2 to 30% by mass of the (a) sulfonic acid group-containing monomer.
It is 20% by mass. When the amount of the (a) sulfonic acid group-containing monomer is less than 1% by mass, the rise of charge and the amount of charge are insufficient, and the image is likely to be affected. If it exceeds 30% by mass, the environmental stability of charging is deteriorated, the charging amount at high temperature and high humidity is low, and the charging amount at low temperature and low humidity is high, so that the charging stability of toner and the maintenance of high image quality are not sufficient. . Further, there is a problem that the developing sleeve and the layer thickness regulating member (blade and roller) are apt to be contaminated and the filming of the photoconductor is caused, and the productivity at the time of toner production by the kneading / pulverizing method is also lowered.

(B) The aromatic monomer having an electron-withdrawing group is preferably 1 to 80% by mass, more preferably 20.
Is about 70% by mass. When the amount of the aromatic monomer having an electron-withdrawing group is less than 1% by mass, the amount of charge is insufficient, and scumming and toner scattering easily occur. On the other hand, if it exceeds 80% by mass, the dispersion in the toner is poor, the charge distribution of the toner is widened, and scumming and toner scattering easily occur, and the maintenance of high image quality is not sufficient.

(C) Acrylic ester monomer and /
Alternatively, the methacrylic acid ester monomer is preferably 1
The amount is 0 to 80% by mass, more preferably 20 to 70% by mass. When the acrylic acid ester monomer and / or the methacrylic acid ester monomer is less than 10% by mass, sufficient environmental stability of charging cannot be obtained, and the pulverizability at the time of toner production by the kneading / pulverization method is insufficient. Therefore, it is not possible to sufficiently prevent the developing sleeve and the layer thickness regulating member (blade and roller) from being contaminated and the photoreceptor filming. If it exceeds 80% by mass, the rise of charge and the amount of charge are insufficient, and the image is likely to be affected.

The aromatic vinyl monomer (d) is preferably 0 to 30% by mass, more preferably 3 to 20% by mass. When the aromatic vinyl monomer exceeds 30% by mass,
The resin becomes hard, the dispersibility in the toner is lowered, the charge distribution is widened, and scumming and toner scattering in the machine are likely to occur. Further, the fixability of the toner, particularly the color developability when the color toners are mixed, becomes poor.

The apparent viscosity of the resin charge control agent used in the present invention measured by a flow tester is 10 ⁴ P (10 ⁴ P).
= 10 ⁴ g / cm · s) is preferably 85 to 110 ° C. If the temperature is lower than 85 ° C, appropriate dispersibility in the toner cannot be obtained, and not only the charge is lowered but also storage stability becomes poor and solidification (aggregation) is likely to occur. In the method of obtaining, sticking is likely to occur in the pulverizing step, which deteriorates productivity.
Further, when the temperature exceeds 110 ° C., the dispersibility in the toner is lowered, the charge distribution is widened, and scumming and toner scattering in the machine are likely to occur. Further, the fixability of the toner, particularly the color developability when the color toners are mixed, becomes poor. Apparent viscosity is 1
The temperature at which 0 ⁴ P (10 ⁴ P = 10 ⁴ g / cm · s) is
For example, using a flow tester, load 10 kg / cm ² ,
Viscosity was measured at an orifice of 1 mm × 1 mm and a heating rate of 5 ° C./min, and the apparent viscosity was 10 ⁴ P (10 ⁴ P = 10 ⁴ g / cm 2).
・ It is a value obtained by reading the temperature of s). Shimadzu CFT-500 type can be used as the flow tester.

Further, the number average molecular weight of the resin charge control agent used in the present invention is preferably 5,000 to 100,000. If it is less than 5,000, appropriate dispersibility in the toner cannot be obtained, and not only the charge is lowered but also sticking occurs in the pulverizing step in the method obtained from the kneading, pulverizing and classifying production steps. Easy and reduces productivity. If it exceeds 100,000, the dispersibility in the toner is lowered, the charge distribution is widened, scumming and toner scattering in the machine are likely to occur, and the fixability and color developability of the toner become poor.

The dispersed particle diameter of the resin charge control agent is, when observed with a transmission electron microscope, a major axis of 0.05 to 1.50 μm.
m, and the minor axis is preferably 0.02 to 1.00 μm. When the major axis exceeds 1.50 μm and the minor axis exceeds 1.00 μm, the charge distribution of the toner becomes wide, and scumming of the toner and toner scattering in the machine are likely to occur. Major axis is 0.05μm, minor axis is 0.02μ
If it is m or less, the rise of charge and the amount of charge are not sufficient,
Easy to affect the image.

The addition amount of the resin charge control agent used in the present invention is preferably 0.1 to 20% by mass, and more preferably 0.5 to 10% by mass based on the toner particles. When the addition amount is less than 0.1% by mass, the rise of charging and the amount of charging are insufficient, and the image is likely to be affected. 20
When the content is more than mass%, the dispersion becomes poor, the charge distribution becomes wide, and the background stain and the toner scattering in the machine are likely to occur.

The resin charge control agent used in the present invention is further combined with a polyester resin or a polyol resin, which are suitable as a binder resin for color toners in terms of color developability and image strength, to obtain appropriate dispersibility. A color toner for electrophotography having a sharp charge distribution can be obtained, and long-term charge stability and high image quality can be obtained.

As the charge control agent, at least one selected from the group consisting of a chromium complex or salt of salicylic acid and an alkylsalicylic acid may be used in combination.

The binder resin used in the present invention is a polyester resin and / or a polyol resin suitable as a binder resin for color toners in terms of color developability and image strength. Color images have several types of toner piled up, so
The toner layer becomes thick, cracks and defects in the image occur due to insufficient strength of the toner layer, and proper gloss is lost. From this point of view, the polyester resin and / or the polyol resin is used in order to maintain appropriate gloss and excellent strength. Further, by using this polyester resin and / or polyol resin, the above general formula (I)
A more excellent effect was obtained on the uniform dispersibility of the magenta colorant represented by

The polyester resin can be generally obtained by an esterification reaction of a polyhydric alcohol and a polycarboxylic acid. Among the monomers constituting the polyester resin in the present invention, examples of alcohol monomers include polyfunctional monomers having a valence of 3 or more, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3- Propylene glycol, 1,4-butadieneol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol and other diols, bisphenol A, hydrogenated bisphenol A, polyoxypropylene Bisphenol A alkylene oxide adducts such as bisphenol A, other dihydric alcohols, or sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol , Tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentane triol, glycerol, diglycerol, 2
-Methylpropanetriol, 2-methyl-1,2,4
Examples include butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxybenzene, and other polyhydric alcohols having 3 or more valences.

Among these monomers, those using a bisphenol A alkylene oxide adduct as a main component monomer are preferably used. Bisphenol A
When an alkylene oxide adduct is used as a constituent monomer, a polyester having a relatively high glass transition point is obtained due to the properties of the bisphenol A skeleton, and the copy blocking resistance and heat resistant storage stability are good. Further, the presence of the alkyl groups on both sides of the bisphenol A skeleton functions as a soft segment in the polymer, and the color developability and the image strength at the time of fixing the toner are improved. Of the bisphenol A alkylene oxide adducts, as the alkylene group, ethylene group and propylene group are preferably used.

Among the monomers constituting the polyester resin in the present invention, examples of the acid monomer include polyfunctional monomers having a valence of 3 or more, such as maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid and phthalic acid. , Isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, or n-dodecenylsuccinic acid, n-
Alkenyl succinic acids such as dodecyl succinic acid or alkyl succinic acids, anhydrides of these acids, esters, other divalent carboxylic acids, and 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid. Acid, 1,2,4-naphthalene tricarboxylic acid, 1,
2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-methylenecarboxypropane, tetra (methylenecarboxyl) methane, Examples thereof include 1,2,7,8-octanetetracarboxylic acid, empol trimer acid, and anhydrides, alkyl esters, alkenyl esters, aryl esters, and other trivalent or higher carboxylic acids thereof.

Specific examples of the above-mentioned alkyl ester, alkenyl ester or aryl ester include 1,
Trimethyl 2,4-benzenetricarboxylate 1,2,
Triethyl 4-benzenetricarboxylate, 1,2,4-
Tri-n-butyl benzenetricarboxylate, 1,2,4-
Isobutyl benzene tricarboxylate, tri-n-octyl 1,2,4-benzene tricarboxylate, tri-2-ethylhexyl 1,2,4-benzene tricarboxylate, 1,
Tribenzyl 2,4-benzenetricarboxylate, 1,
2,4-benzenetricarboxylic acid tris (4-isopropylbenzyl) and the like can be mentioned.

As the polyol resin used in the present invention, the end of the epoxy resin is capped from the viewpoints of environmental stability of charging, fixing stability, color reproducibility, gloss stability, curl resistance after fixing, and the like. Further, those having a polyoxyalkylene portion in the main chain are preferable. For example, it can be obtained by reacting an epoxy resin having a glycidyl group at both ends with an alkylene oxide adduct of a dihydric phenol having a glycidyl group at both ends with a dihalide, an isocyanate, a diamine, a diol, a polyhydric phenol, or a dicarboxylic acid. Of these, it is most preferable to react a dihydric phenol from the viewpoint of reaction stability. In addition, it is also preferable to use polyhydric phenols and polyhydric carboxylic acids in combination with dihydric phenol within the range where gelation does not occur.

Examples of the alkylene oxide adduct of dihydric phenol having glycidyl groups at both ends used in the present invention include the following. Examples thereof include reaction products of ethylene oxide, propylene oxide, butylene oxide, or a mixture thereof with bisphenol such as bisphenol A and bisphenol F. The obtained adduct may be glycidylated with epichlorohydrin or β-methylepichlorohydrin before use. In particular, glycidyl ether of an alkylene oxide adduct of bisphenol A represented by the following general formula (II) is preferable.

[0080]

[Chemical 3] (In the formula, R is —CH ₂ —CH ₂ —, —CH ₂ —CH (CH ₃ ).
Or a —CH ₂ —CH ₂ —CH ₂ — group, and n, m
Is the number of repeating units, each of which is 1 or more, and n +
m = 2-6. )

The method for producing these binder resins is not particularly limited, and bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization and the like can be used.

Here, the relationship between the chargeability of the binder resin and the acid value is almost proportional, and it is known that the higher the acid value, the higher the chargeability of the binder resin. It also affects the environmental stability of. That is, if the acid value is high, the charge amount will be high under low temperature and low humidity, and the charge amount will be low under high temperature and high humidity, and background stains, image density, and color reproducibility will be large, making it difficult to maintain high image quality. . Therefore, the acid value of the binder resin is preferably 20 KOHmg / g or less,
It is particularly preferably 5 KOHmg / g or less, and at this time, the dispersibility of the compound of the general formula (I) in the binder resin was also good. Here, the acid value of the resin is JIS K
It measured according to 0070.

The content of the compound represented by the general formula (I) is 1 to 20 parts by mass, preferably 3 to 10 parts by mass with respect to 100 parts by mass of the binder resin. Here, when the content of the compound represented by the general formula (I) is less than 1 part by mass, sufficient coloring property cannot be obtained. Also, the content is 2
If the amount exceeds 0 parts by mass, the transparency deteriorates and, particularly when reproducing the halftone part, a minute electrostatic latent image on the photoconductor must be developed with a very small amount of toner. Roughness in the tones tends to be noticeable, and in addition, stains tend to be noticeable.

Further, as the colorant used in the magenta toner of the present invention, in addition to the compound of the general formula (I), for example, red iron oxide, red lead, lead red, cadmium red, cadmium mercury red, antimony red, permanent red 4R. , Para Red, Fire Red, Parachloro Ortho Nitroaniline Red, Resor Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F
4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resor Rubin GX, Permanent Red (F5R, FBB), Pigment Scarlet 3
B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10
B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red,
Conventionally known dyes and pigments such as pyrazolone red, polyazo red, chrome vermilion, benzidine orange, perinone orange and oil orange may be used in combination. The content of these colorants is usually 1 to 20 parts by mass, and preferably 3 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

Further, in order to improve the releasability of the toner from the fixing member at the time of fixing and to improve the fixability of the toner, it is possible to include a releasing agent in the toner. Here, as the release agent, conventionally known release agents can be used, and examples thereof include low molecular weight polyolefin waxes such as low molecular weight polyethylene and low molecular weight polypropylene, synthetic hydrocarbon waxes such as Fischer-Tropsch wax, beeswax, carnauba. Natural waxes such as wax, candelilla wax, rice wax and montan wax, petroleum waxes such as paraffin wax and microcrystalline wax, higher fatty acids such as stearic acid, palmitic acid and myristic acid, and metal salts of higher fatty acids, higher fatty acids Examples thereof include amides and various modified waxes thereof. These releasing agents can be used alone or in combination of two or more kinds, and particularly by using carnauba wax, good releasing property can be obtained.

The content of the release agent is 100% by weight of the binder resin 100.
Generally 1 to 15 parts by mass, preferably 2 to parts by mass.
10 parts by mass. If it is less than 1 part by mass, the effect of preventing offset is insufficient, and if it exceeds 15 parts by mass, the transferability, durability and the like are deteriorated.

Further, the toner of the present invention may contain a magnetic material and be used as a magnetic toner. Specific magnetic materials include magnetite, hematite, iron oxides such as ferrite, metals such as cobalt and nickel, or these metals and aluminum, copper, lead, magnesium,
Examples thereof include alloys with metals such as tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten and vanadium, and mixtures thereof. These magnetic materials have an average particle size of 0.
It is preferably about 1 to 2 μm, and the content is usually 20 to 200 parts by mass, preferably 40 to 150 parts by mass with respect to 100 parts by mass of the binder resin.

As an example of the method for producing the magenta toner in the present invention, first, the binder resin, the colorant, and water are thoroughly mixed by a mixer such as a Henschel mixer, and then the ordinary two rolls and three rolls are used. In addition to rolls, a method of using a Banbury mixer as an open type or a method of using an open type kneader such as a continuous two roll kneader manufactured by Mitsui Mining Co., Ltd. is used for heat kneading to obtain a masterbatch pigment.

Next, the masterbatch pigment is mixed with a binder resin, a charge control agent, and if necessary, other materials such as a release agent, and sufficiently mixed by a mixer such as a Henschel mixer. Further, a batch type twin roll, a Banbury mixer or a continuous type twin screw extruder, for example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type twin screw extruder manufactured by Toshiba Machine Co., Ltd., TEX manufactured by Japan Steel Works Ltd. Mold twin-screw extruder, KCK
Company twin screw extruder, Ikegai Iron Works PCM type twin screw extruder, Kurimoto Iron Works KEX type twin screw extruder, continuous single screw kneader, such as Bus Co Co kneader After thoroughly kneading the constituent materials using a machine, cooling, coarsely crushing with a hammer mill, etc., further finely crushing with a fine crusher using a jet stream or a mechanical crusher, and a classifier using a swirling air stream The toner particles are obtained by classifying the particles into a predetermined particle size by a classifier using the Coanda effect.

Then, the toner particles and the additives are thoroughly mixed by a mixer such as a Henschel mixer (manufactured by Mitsui Miike Co., Ltd.), a mechanofusion system (manufactured by Hosokawa Micron Co., Ltd.), a mechanomill (manufactured by Okada Seiko Co., Ltd.) and the like, if necessary. 10
After passing through a sieve with an opening of about 0 μm or less, aggregates and coarse particles are removed.

In the method for producing magenta toner of the present invention, the peripheral speed of the stirring blade tip at the time of mixing the toner particles and the additive is 25 to 45 m / sec, and the total mixing of the toner particles and the additive is performed. At least 15 hours
It is preferably 0 sec or more. Here, as a method of mixing the toner particles and the additive, a method of mixing the toner particles and the additive with one agitation, a method of providing a pause time between them and performing a plurality of agitation, and the like can be mentioned. In the present invention, either method can be preferably used,
Particularly, the total mixing time at this time is preferably 150 sec or more.

When the peripheral speed of the stirring blade tip is less than 25 m / sec, or the total mixing time of the toner particles and the additive is 150
If it is less than sec, sufficient mixing is not performed, so
The additives are not uniformly mixed, and the released additives adhere to the image carrier such as the photoconductor, the developing roller and the carrier,
It is likely to cause development problems such as filming, and
It becomes easy to cause a background stain and a decrease in developability due to poor charging of the toner. On the contrary, the peripheral speed of the tip of the stirring blade is 45 m / s.
If it is higher than ec, the additive strongly adheres to the toner particles and is easily embedded in the surface of the toner particles, so that aggregation easily occurs and sufficient fluidity cannot be obtained. Further, the toner may melt due to heat generated during mixing, and in particular, in the case of color toner, it is common to use a low-softening binder resin having many low molecular weight components. The trend is more pronounced.

The particle size of the magenta toner of the present invention is
The weight average diameter is preferably 2.5 to 10 μm,
Particularly preferably, it is 4 to 8 μm. When the particle size is smaller than 2.5 μm, background stains and toner scattering may occur during development, and fluidity may be deteriorated to hinder toner replenishment and cleaning properties. Further, when the particle diameter is larger than 10 μm, dust in the image, deterioration of resolution, etc. may become a problem, and particularly in the case of a color image, the influence is great.

By adopting the constitution of the present invention, it is possible to obtain a high effect against background stains, toner scattering, filming, etc. even with toner having a small particle size.

Here, the weight average particle diameter of the toner can be measured by various methods, but in the present invention, the Coulter Multisizer was used. That is, a Coulter Multisizer IIe type (manufactured by Beckman Coulter, Inc.) is used as a measuring device, an interface (manufactured by Nikkaki Co., Ltd.) that outputs a number distribution and a volume distribution, and a personal computer are connected, and the electrolyte is a first-class chloride. With sodium 1
% NaCl aqueous solution was prepared.

The measuring method is as follows:
A surfactant, preferably 0.1 to 5 ml of alkylbenzene sulfonate, is added as a dispersant to 150 ml,
Furthermore, add 2 to 20 mg of the measurement sample, and use an ultrasonic disperser to
Dispersion processing was performed for 3 minutes. Further, 100 to 200 ml of the electrolytic aqueous solution was placed in another beaker, the sample dispersion liquid was added thereto to a predetermined concentration, and 1 was used as an aperture by the Coulter Multisizer IIe type.
This was done by measuring the average of 50,000 particles using a 00 μm aperture.

The magenta toner of the present invention can be applied to both a one-component developer and a two-component developer. In the case of a two-component developer, it is used as a mixture with a carrier.

Here, as the carrier, conventionally known carriers can be used, and examples thereof include magnetic powders such as iron powder, ferrite powder, nickel powder, and glass beads, and in particular, the surface of these. Is preferably coated with a resin or the like.

In this case, as the resin used, polyfluorocarbon, polyvinyl chloride, polyvinylidene chloride, phenol resin, polyvinyl acetal, acrylic resin,
Silicone resin etc. are mentioned.

As a method of forming this resin layer, the resin may be applied to the surface of the carrier by a method such as a spraying method or a dipping method as in the conventional method. The amount of the resin used is usually preferably 1 to 10 parts by mass with respect to 100 parts by mass of the carrier. The resin film thickness is preferably 0.02 to 2 μm, particularly preferably 0.05 to 1 μm.
m, and more preferably 0.1 to 0.6 μm. When the film thickness is large, the fluidity of the carrier and the developer tends to be low, and when the film thickness is thin, the film is liable to be affected by abrasion of the film over time.

Here, the average particle size of these carriers is usually 10 to 100 μm, preferably 30 to 60 μm. Further, the proper mixing ratio of the toner and the carrier is generally about 0.5 to 7.0 parts by mass of the toner to 100 parts by mass of the carrier.

When the magenta toner of the present invention is used in an image forming apparatus, the toner is filled in a container, and the container filled with the toner is distributed separately from the image forming apparatus, and the user installs it in the image forming apparatus. It is generally used for image formation. What is used as the container is not limited and can be used without being limited to the conventional bottle type or cartridge type.

The image forming apparatus is not limited as long as it is an apparatus for forming an image by an electrophotographic method, and includes, for example, a copying machine, a printer, a FAX and the like.

[0104]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the image forming apparatus of the present invention will be described.

FIG. 1 is a schematic configuration diagram of a copying machine as an image forming apparatus according to the embodiment. This copying machine includes a copying apparatus main body 100 (hereinafter referred to as a printer unit), a paper feeding table 200 (hereinafter referred to as a paper feeding unit), and a copying apparatus main body 10.
A scanner 300 (hereinafter referred to as a scanner section) mounted on the scanner 0, and an automatic document feeder (ADF) 400 (hereinafter referred to as a document feeder) mounted on the scanner section. Further, a control unit (not shown) for controlling the operation of each device in the copying machine is also provided.

The scanner unit 300 includes the contact glass 3
2 reads the image information of the document placed on the sensor 2
And the image information read is sent to this control unit.
Based on the image information received from the scanner unit 300, the control unit controls a laser, an LED, or the like (not shown) provided in the exposure device 21 of the printer unit 100 to control the photosensitive drums 40Bk, 40Y, 40M, and 40C. The laser writing light L is emitted toward. By this irradiation, an electrostatic latent image is formed on the surfaces of the photoconductor drums 40Bk, 40Y, 40M, 40C, and this latent image is developed into a toner image through a predetermined developing process.

The printer section 100 includes the exposure device 21.
In addition, a primary transfer device 62, a secondary transfer device 22, a fixing device 25, a paper discharge device 56, a toner supply device (not shown), and the like are also provided. The developing process will be described in detail later.

The paper feeding section 200 is provided with a multi-stage paper feeding cassette 44 in the paper bank 43, a paper feeding roller 42 for feeding the transfer paper as an image carrier from the paper feeding cassette, and a paper feeding path for separating the fed transfer paper. Separation roller 4 sent to 46
5. The paper feed path 48 of the printer unit 100 is provided with a carrying roller 47 for carrying the transfer paper. In the apparatus of the present embodiment, in addition to this paper feeding unit, manual feeding is also possible, and one sheet of manual feeding tray 51 for manual feeding and a sheet of transfer paper on the manual feeding tray are directed toward the manual feeding path 53. Separation rollers 52 for separating the parts are also provided on the side surface of the apparatus. The registration roller 49 discharges only one sheet of transfer paper placed on the paper feed cassette 44 or the manual feed tray 51, and the intermediate transfer belt 10 as an intermediate transfer member and the secondary transfer device 2 are discharged.
2 is sent to the secondary transfer nip portion located between

In the above structure, when copying a color image, the original is set on the original table 30 of the original conveying section 400, or the original conveying section 400 is opened and the original is placed on the contact glass 32 of the scanner section 300. The document is set, the document feeding unit 400 is closed, and the document is pressed. Then, when a start switch (not shown) is pressed, the document is conveyed onto the contact glass 32 when the document is set on the document conveyance section 400, and immediately after the document is set on the other contact glass 32, the scanner is immediately scanned. The part 300 is driven to travel the first traveling body 33 and the second traveling body 34. And
The first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34,
The image information is read by being reflected by the mirror of the second traveling body 34 and entering into the reading sensor 36 through the imaging lens 35.

Then, when the image information is received from the scanner section 300, the laser writing as described above and the developing process described later are carried out so that the photosensitive drums 40Bk, 40B.
One of four registration rollers is operated to form a toner image on Y, 40M, and 40C and to feed a transfer paper of a size corresponding to the image information.

Along with this, a driving motor (not shown) rotationally drives one of the supporting rollers 14, 15, 16 to rotate the other two supporting rollers, and the intermediate transfer belt 1 is driven.
0 is conveyed by rotation. At the same time, the individual image forming units 1
8 the photosensitive drum 40Bk, 40Y, 40M, 40
Rotate C to rotate the photoconductor drums 40Bk, 40Y, 40
Black, yellow, magenta, and cyan single-color images are formed on M and 40C, respectively. Then, as the intermediate transfer belt 10 is conveyed, the single color images are sequentially transferred to form a composite color image on the intermediate transfer belt 10.

On the other hand, one of the paper feed rollers 42 of the paper feed unit 200
One of them is selectively rotated, and the transfer paper is fed from one of the paper feed cassettes 44, separated by the separation roller 45 one by one, and fed to the paper feed path 4.
6 and guides it to the paper feed path 48 in the copying machine main body 100 by the conveyance roller 47, and stops this transfer paper by abutting it on the registration roller 49. Alternatively, the paper feed roller 50 is rotated to feed out the transfer paper on the manual feed tray 51, and the separation roller 52
The sheets are separated one by one and placed in the manual paper feed path 53, and similarly abut against the registration rollers 49 and stop.

Then, the registration roller 49 is rotated in synchronism with the composite color image on the intermediate transfer belt 10 and transferred to the secondary transfer nip portion which is the contact portion between the intermediate transfer belt 10 and the secondary transfer roller 23. The paper is fed, the color image is secondarily transferred by the influence of the transfer electric field formed in the nip, the contact pressure, etc., and the color image is recorded on the transfer paper.

The transfer paper after the image transfer is sent to the fixing device 25 by the conveyor belt 24 of the secondary transfer device, and the fixing device 2
After the toner image is fixed by applying pressure and heat by the pressure roller 27 at 5, the discharge roller 56 discharges the paper to the discharge tray 57.
Discharge on top.

Next, details of the printer section 100 in the copying machine of this embodiment will be described. FIG. 2 is an enlarged view of a main part of the printer unit 100. This printer unit 100
Are three supporting rollers 14 and 1 as an intermediate transfer belt.
The intermediate transfer belt 10 designated by 5 and 16 is provided side by side so as to face the intermediate transfer belt, and serves as a latent image carrier that carries a toner image of one of black, yellow, magenta, and cyan on the surface. 4 photoconductor drums 4
0Bk, 40Y, 40M, 40C and developing units 61Bk, 6 for forming a toner image on the surface of the photosensitive drum.
1Y, 61M, 61C. Further, the photoconductor cleaning devices 63Bk, 63Y, 63M for removing the toner remaining after the primary transfer from the surface of the photoconductor drum,
It also has 63C. The plurality of photosensitive drums 40B
k, 40Y, 40M, 40C, developing unit 18Bk,
A tandem image forming apparatus 20 is configured by four image forming units 18Bk, 18Y, 18M, and 18C, which include 18Y, 18M, and 18C, and the photoconductor cleaning devices 63Bk, 63Y, 63M, and 63C.

Further, on the left side of the support roller 15, there is provided a belt cleaning device 17 for removing the residual toner remaining on the intermediate transfer belt 10 after the toner image is transferred onto the transfer paper. The belt cleaning device 17 includes two fur brushes 90 as cleaning members.
91 is provided. The fur brushes 90, 91 are, for example, φ20 mm, acrylic carbon, 6.25 D / F, 10
Ten thousand / inch ² , 1 × 10 ⁷ Ω is used, and it is provided so as to come into contact with the intermediate transfer belt 10 and rotate in the counter direction. And each fur brush 90,
To 91, biases having different polarities are applied from a power source (not shown). And these fur brushes 90, 91
, Metal rollers 92 and 93 are brought into contact with each other so as to be rotatable in the forward or reverse direction with respect to the fur brush.

In the present embodiment, the intermediate transfer belt 10
(-) Voltage is applied from the power supply 94 to the metal roller 92 on the upstream side in the rotation direction of the power supply 9 to the metal roller 93 on the downstream side.
A (+) voltage is applied from 5. Those metal rollers 9
The tips of blades 96 and 97 are pressed against 2, 93, respectively.

Then, with the rotation of the intermediate transfer belt 10 in the direction of the arrow, for example, a bias of (-) is first applied using the fur brush 90 on the upstream side to clean the surface of the intermediate transfer belt 10. If the metal roller 92
When -700V is applied to the fur brush 90, the fur brush 90 is -400.
It becomes V, and the (+) toner on the intermediate transfer belt 10 can be transferred to the fur brush 90 side. The toner transferred to the fur brush side is further transferred from the fur brush 90 to the metal roller 92 by the potential difference, and the blade 96
To scrape off.

Thus, the toner on the intermediate transfer belt 10 is removed by the fur brush 90.
There is still a lot of toner left on top of 0. The toners are negatively charged by the negative (-) bias applied to the fur brush 90. This is considered to be charged by charge injection or discharge. Next, the fur brush 91 on the downstream side is used to apply a (+) bias this time to perform cleaning, thereby removing those toners. The removed toner is transferred from the fur brush 91 to the metal roller 93 due to the potential difference,
It is scraped off by the blade 97. The toner scraped off by the blades 96 and 97 is collected in a tank (not shown).
These toners may be returned to the developing device 61 using a toner recycling device described later.

On the other hand, most of the toner has been removed from the surface of the intermediate transfer belt 10 that has been cleaned by the fur brush 91, but some toner still remains. The toner remaining on these intermediate transfer belts 10 is charged to (+) by the (+) bias applied to the fur brush 91 as described above. The toner charged to (+) is transferred to the photoconductor drums 40Bk, 40Y, 40M, and 40C by the transfer electric field applied at the primary transfer position, and the photoconductor cleaning devices 63Bk, 63Y, and 63B.
It can be recovered with M and 63C.

On the other hand, the secondary transfer device 22 is provided on the side opposite to the tandem image forming device 20 with the intermediate transfer belt 10 interposed therebetween.
Equipped with. In the present embodiment, the secondary transfer device 22 is configured by spanning a secondary transfer belt 24 between two rollers 23 and pressing the secondary transfer belt 24 against the third support roller 16 via the intermediate transfer belt 10. The secondary transfer nip portion is formed, and the color toner image on the intermediate transfer belt 10 is secondarily transferred onto the transfer paper. Intermediate transfer belt 1 after secondary transfer
Reference numeral 0 denotes a belt cleaning device 17, which removes residual toner remaining on the intermediate transfer belt 10 after image transfer,
Preparing for another image formation by the tandem image forming apparatus 20.

The above-mentioned secondary transfer device 22 is also provided with a transfer paper carrying function for carrying the transfer paper after the image transfer to the fixing device 25. As a matter of course, a transfer roller or a non-contact charger may be arranged as the secondary transfer device 22, and in such a case, it is difficult to provide this transfer paper transport function together.

The registration roller 49 is generally grounded and used in many cases, but it is also possible to apply a bias for removing the paper dust of the transfer paper. For example, a bias is applied using a conductive rubber roller. Diameter 18mm
Then, the surface is made of a conductive NBR rubber having a thickness of 1 mm. The electrical resistance is about 1 × 10 ¹⁰ Ω · cm in terms of volume resistance of the rubber material, and the applied voltage is −80 on the toner transfer side (front side).
A voltage of about 0 V is applied. Also, the back side of the paper is +
A voltage of about 200 V is applied.

Generally, in the intermediate transfer method, the paper dust does not easily move to the photoconductor, so that it is not necessary to consider the paper dust transfer, and it may be grounded. Also, as the applied voltage, D
Although a C bias is applied, this may be an AC voltage having a DC offset component in order to charge the transfer paper more uniformly. The paper surface after passing through the resist roller 49 thus biased is slightly charged to the negative side. Therefore, in the transfer from the intermediate transfer belt 10 to the transfer paper, the transfer condition may be changed and the transfer condition may be changed as compared with the case where no voltage is applied to the registration roller 49.

In the present embodiment, the secondary transfer device 2
Below the fixing device 25 and the fixing device 25, a transfer paper reversing device 28 (see FIG. 1) is provided in parallel with the tandem image forming device 20 described above so as to reverse the transfer paper so as to record images on both sides of the transfer paper. As a result, after the image is fixed on one side of the transfer paper,
Switch the transfer paper path to the transfer paper reversing device side with the switching claw,
Therefore, the toner image may be inverted and transferred again at the maintenance transfer nip, and then discharged onto the discharge tray.

Next, the tandem image forming apparatus 20 will be described. FIG. 3 is a partially enlarged view of the tandem image forming apparatus 20. Four image forming units 18Bk, 18
Since Y, 18M, and 18C have the same configuration, the four color symbols Bk, Y, M, and C are omitted and the configuration of one unit will be described in detail. As shown in FIG. 3, the image forming unit includes a charging device 60, a developing device 61, a primary transfer device 62 as a primary transfer means, and a photoconductor cleaning device 6 around the photoconductor drum 40.
3, a neutralization device 64 and the like are provided.

In the illustrated example, the photosensitive drum 40 has a drum shape in which a photosensitive layer is formed by coating an organic photosensitive material having photosensitivity on a tube made of aluminum or the like, but it may have an endless belt shape. Good.

Although not shown, at least the photosensitive drum 40 is provided, and the process cartridge is formed by all or part of the portion forming the image forming unit 18.
The maintainability may be improved by making it attachable to and detachable from the copying machine main body 100 at once.

Further, among the parts constituting the image forming unit 18, the charging device 60 is formed in a roller shape in the illustrated example, and the photosensitive drum 40 is charged by contacting the photosensitive drum 40 and applying a voltage thereto. I do. Of course, charging can also be performed with a non-contact scorotron charger.

The developing device 61 may use a one-component developer, but in the illustrated example, a two-component developer comprising a magnetic carrier and a non-magnetic toner is used. Then, the agitating portion 66 that conveys the two-component developer while stirring and supplies the two-component developer to the developing sleeve 65 and attaches it, and the toner of the two-component developer attached to the developing sleeve 65 to the photosensitive drum. The developing unit 67 for transferring to 40 is provided, and the stirring unit 66 is located at a position lower than the developing unit 67.

The stirring section 66 includes two parallel screws 6
8 is provided, and the space between the two screws 68 is partitioned by a partition plate 69 except for both ends (see FIG. 4). A toner concentration sensor 71 is provided on the developing case 70.

In the developing section 67, a developing sleeve 65 is provided facing the photosensitive drum 40 through the opening of the developing case 70, and a magnet 72 is fixedly provided in the developing sleeve 65. Further, a doctor blade 73 is provided with its tip approaching the developing sleeve 65. In the illustrated example, the distance between the doctor blade 73 and the developing sleeve 65 at the closest position is set to 500 μm.

The developing sleeve 65 has a non-magnetic rotatable sleeve-like shape, and has a plurality of magnets 7 inside.
2 are arranged. Since the magnet 72 is fixed, a magnetic force can be applied when the developer passes through a predetermined place. In the illustrated example, the developing sleeve 65 has a diameter of 18 mm, and the surface is formed by sandblasting or a process of forming a plurality of grooves having a depth of 1 to several mm so that RZ falls within the range of 10 to 30 μm. .

The magnet 72 is, for example, N1 in the rotation direction of the developing sleeve 65 from the position of the doctor blade 73,
It has five magnetic poles S1, N2, S2, and S3.

The developer forms a magnetic brush by the magnet 72 and is carried on the developing sleeve 65. The developing sleeve 65 is disposed in a region on the S1 side of the magnet 72 that forms a magnetic brush of developer so as to face the photosensitive drum 40.

With the above structure, the two-component developer is conveyed and circulated while being stirred by the two screws 68, and is supplied to the developing sleeve 65. The developer supplied to the developing sleeve 65 is drawn up and held by the magnet 72,
A magnetic brush is formed on the developing sleeve 65. The magnetic brush is cut into an appropriate amount by the doctor blade 73 as the developing sleeve 65 rotates. The developer that has been cut off is returned to the stirring unit 66.

The toner of the developer carried on the developing sleeve 65 is transferred to the photosensitive drum 40 by the developing bias voltage applied to the developing sleeve 65, and the electrostatic latent image on the photosensitive drum 40 is visualized. Image. After the visible image is formed, the developer remaining on the developing sleeve 65 is separated from the developing sleeve 65 and returns to the stirring unit 66 in the absence of the magnetic force of the magnet 72. By repeating this, when the toner density in the stirring section 66 becomes low, the toner density sensor 71 detects it and the toner is replenished to the stirring section 66.

In the apparatus of the present embodiment, the setting of each part is such that the linear velocity of the photosensitive drum 40 is 200 mm / s, the linear velocity of the developing sleeve 65 is 240 mm / s, the diameter of the photosensitive drum 40 is 50 mm, and the developing The diameter of the sleeve 65 is 18
The development process is performed in mm. The charge amount of the toner on the developing sleeve 65 is preferably in the range of -10 to -30 μC / g. The developing gap GP, which is the gap between the photosensitive drum 40 and the developing sleeve 65, is 0.8 mm as in the conventional case.
Can be set in the range of 0.4 mm to 0.4 mm, and the developing efficiency can be improved by reducing the value.

Further, the thickness of the photosensitive member is 30 μm, the beam spot diameter of the optical system is 50 × 60 μm, and the light amount is 0.4.
It is set to 7 mW. Further, the charge (before exposure) potential V0 of the photosensitive drum 40 is −700 V, and the post-exposure potential VL is −12.
The developing step is performed by setting the developing bias voltage to 0V and the developing bias voltage to -470V, that is, 350V.

The primary transfer device 62 is composed of a roller-shaped primary transfer roller, and is provided by pressing the intermediate transfer belt 10 against the photosensitive drum 40. A conductive roller 74 is provided between the primary transfer rollers 62 in contact with the base layer side of the intermediate transfer belt 10. The conductive roller 74 prevents the bias applied by each primary transfer roller 62 at the time of transfer from flowing into each adjacent image forming unit 18 through the medium resistance base layer.

The photoconductor cleaning device 63 uses a cleaning blade 75 made of polyurethane rubber, for example.
Its tip is pressed against the photosensitive drum 40. Furthermore,
In order to improve the cleaning property, in this embodiment,
A fur brush 76 having a contact conductivity whose outer periphery contacts the photosensitive drum 40 is rotatably provided in the arrow direction. Also,
A metal electric field roller 77 for applying a bias to the fur brush 76 is rotatably provided in the arrow direction.
The tip of scraper 78 is pressed against 7. further,
A recovery screw 79 for recovering the removed toner is also provided.

With the photoconductor cleaning device 63 having the above structure, the fur brush 76 rotating in the counter direction with respect to the photoconductor drum 40 removes the residual toner on the photoconductor drum 40. The toner attached to the fur brush 76 is removed by the electric field roller 77 to which a bias is applied, which contacts the fur brush 76 in the counter direction and rotates. The toner attached to the electric field roller 77 is cleaned by the scraper 78. The toner collected by the photoconductor cleaning device 63 is brought to one side of the photoconductor cleaning device 63 by the collection screw 79, and is returned to the developing device 61 by the toner recycling device 80 described later for reuse.

The static eliminator 64 uses a static eliminator and irradiates light to initialize the surface potential of the photosensitive drum 40.

The developing process with the above configuration will be described. As the photoconductor drum 40 rotates, first the charging device 6
At 0, the surface of the photosensitive drum 40 is uniformly charged, and the writing light L is irradiated to form an electrostatic latent image on the photosensitive drum 40. Thereafter, the electrostatic latent image is developed by the developing device 61 to develop the toner into a toner image, and the toner image is primarily transferred onto the intermediate transfer belt 10 by the primary transfer roller 62. On the surface of the photoconductor drum 40 after the image transfer, the residual toner is removed by the photoconductor cleaning device 63, and the charge removing device 6
The charge is removed in step 4 to prepare for another image formation. On the other hand, the residual toner removed from the surface of the photoconductor drum is used again for development by a toner recycling device described later. Here, the order of colors for forming an image is not limited to the above, but differs depending on the aim and characteristics of the image forming apparatus.

Next, the toner recycling mechanism will be described with reference to FIGS. 4 and 5. FIG. 4 is a perspective view showing a layout of the photoconductor drum 40 and its adjacent member, and FIG. 5 is a perspective view showing a recovery screw in the photoconductor cleaning device 63.

As shown in FIG. 5, the recovery screw 79 of the photoconductor cleaning device 63 is provided with a roller portion 82 having a pin 81 at one end. Then, the roller portion 82
On one side, one side of the belt-shaped collected toner conveying member 83 of the toner recycling device 80 is hooked, and the collected toner conveying member 83
Insert the pin 81 into the long hole 84 of the. Collected toner conveying member 8
Blades 85 are provided at regular intervals on the outer circumference of 3, and the other side is hooked on a roller portion 87 of a rotating shaft 86. The collected toner carrying member 83 is put in the carrying path case 88 shown in FIG.

The transport path case 88 is formed integrally with the cartridge case 89, and one end of the above-mentioned two screws 68 of the developing device 61 is inserted into the end portion of the developing device 61 side. Then, while driving force is transmitted from the outside to rotate the recovery screw 79, the recovery toner transfer member 83 is rotationally transferred, and the toner recovered by the photoconductor cleaning device 63 is transferred to the developing device 61 through the transfer path case 88. Then, the screw 68 is rotated to insert it into the developing device 61.
After that, as described above, the two screws 68 carry and circulate the developer already in the developing device 61 while stirring, and use it for development.

[0148]

The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. Further, in the following examples, parts and% are based on mass unless otherwise specified.

(Synthesis Example of Resin Charge Control Agent) Synthesis Example 1 350 parts of 3,4-dichlorophenylmaleimide and 2-
Acrylamide-2-methylpropanesulfonic acid 100
One part was subjected to copolymerization in dimethylformaldehyde (DMF) at a boiling point for 8 hours using ditertiary butyl peroxide as an initiator. Then add n-butyl acrylate to 500
And 50 parts of styrene were added, and graft polymerization was carried out for 4 hours using ditertiary butyl peroxide as an initiator.
DMF was removed by a vacuum dryer, and volume resistance was 10.5L.
A resin charge control agent A having a weight average molecular weight of 10,000, an apparent viscosity of 10 ⁴ P (10 ⁴ P = 10 ⁴ g / cm · s) and a temperature of 96 ° C. was obtained.

Synthesis Example 2 600 parts of m-nitrophenylmaleimide and 100 parts of perfluorooctanesulfonic acid were copolymerized in dimethylformaldehyde (DMF) at a boiling point for 8 hours using ditertiarybutyl peroxide as an initiator. Next, 250 parts of 2-ethylhexyl acrylate and 30 parts of styrene were added.
In addition, after graft-polymerizing with ditertiary butyl peroxide as an initiator for 4 hours, DMF was removed by a vacuum dryer to obtain a volume resistance of 9.5 Log Ω · cm, a weight average molecular weight of 5,500, and an apparent viscosity of 10 ⁴ P. (10 ⁴ P =
A resin charge control agent B having a temperature of 10 ⁴ g / cm · s) of 85 ° C. was obtained.

Synthesis Example 3 500 parts of 3,4-dichlorophenylmaleimide and 2-
Acrylamide-2-methylpropanesulfonic acid 150
One part was subjected to copolymerization in dimethylformaldehyde (DMF) at a boiling point for 8 hours using ditertiary butyl peroxide as an initiator. Then, n-butyl acrylate is added to 350
Part, 250 parts of α-methylstyrene was added, and graft polymerization was carried out for 4 hours using ditertiary butyl peroxide as an initiator, and then DMF was removed by a vacuum dryer to obtain a volume resistance of 11.5 LogΩ · cm and a weight average molecular weight of 96, 00
0, apparent viscosity 10 ⁴ P (10 ⁴ P = 10 ⁴ g / cm ·
A resin charge control agent C having a temperature of s) of 110 ° C. was obtained.

Synthesis Example 4 400 parts of 3,4-dichlorophenylmaleimide and 200 parts of perfluorooctanesulfonic acid were copolymerized in dimethylformaldehyde (DMF) at a boiling point for 8 hours with ditertiarybutyl peroxide as an initiator. Next, 300 parts of n-butyl acrylate was added, and graft polymerization was carried out for 4 hours using ditertiary butyl peroxide as an initiator, and then DMF was removed by a vacuum dryer to obtain a volume resistance of 10.4 LogΩ · cm and a weight average molecular weight of 15, 00
0, apparent viscosity 10 ⁴ P (10 ⁴ P = 10 ⁴ g / cm ·
A resin charge control agent D having a temperature of s) of 105 ° C. was obtained.

Synthesis Example 5 3,4-dichlorophenylmaleimide 400 parts and 2-
Acrylamide-2-methylpropanesulfonic acid 100
One part was subjected to copolymerization in dimethylformaldehyde (DMF) at a boiling point for 8 hours using ditertiary butyl peroxide as an initiator. Then add n-butyl acrylate to 500
Parts and 100 parts of styrene were added, and graft polymerization was carried out for 4 hours using ditertiary butyl peroxide as an initiator, and then DMF was removed by a vacuum dryer to give a volume resistance of 9.3.
A resin charge control agent E having a log Ω · cm, a weight average molecular weight of 30,000 and an apparent viscosity of 10 ⁴ P (10 ⁴ P = 10 ⁴ g / cm · s) and a temperature of 101 ° C. was obtained.

Synthesis Example 6 3,4-dichlorophenylmaleimide 400 parts and 2-
Acrylamide-2-methylpropanesulfonic acid 200
One part was subjected to copolymerization in dimethylformaldehyde (DMF) at a boiling point for 8 hours using ditertiary butyl peroxide as an initiator. Then add n-butyl acrylate to 200
Parts, 400 parts of styrene were added and dissolved, and then DMF was removed by a vacuum dryer to obtain a volume resistance of 11.6 LogΩ · c.
m, weight average molecular weight 119000, apparent viscosity 10
^The temperature at which ⁴ P (10 ⁴ P = 10 ⁴ g / cm · s) is 11
A resin charge control agent F having a temperature of 5 ° C. was obtained.

Synthesis Example 7 450 parts of 3,4-dichlorophenylmaleimide and par
150 parts of fluorooctane sulfonic acid was added to dimethylform
Ditertiary butyl in aldehyde (DMF) at boiling point
Copolymerization was carried out with peroxide as an initiator for 3 hours. Next
Add 500 parts of methyl acrylate and add
Graft polymerization for 4 hours using chill peroxide as an initiator
After that, the DMF was removed by a vacuum dryer to remove the volume resistance.
9.2 Log Ω · cm, weight average molecular weight 3,000, see
Applied viscosity is 10^FourP (10^FourP = 10 ^Fourg / cm · s)
A resin charge control agent G having a temperature of 80 ° C. was obtained.

(Synthesis Example of Polyester Resin) Synthesis Example 1 Stirrer, thermometer, nitrogen inlet, flow-down condenser,
In a four-neck separable flask equipped with a cooling tube, 740 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene (2.
2) -2,2-bis (4-hydroxyphenyl) propane 300 g, dimethyl terephthalate 466 g, isododecenyl succinic anhydride 80 g, and tri-n-butyl 1,2,4-benzenetricarboxylate 114 g were added together with the esterification catalyst. In a nitrogen atmosphere, the atmospheric pressure was raised to 210 ° C. in the first half, and the reaction was performed while stirring at 210 ° C. in the latter half under reduced pressure. Acid value 2.3 KOHmg / g, hydroxyl value 28.0 KOHmg
A was obtained as a polyester resin having a softening point of 106 ° C / g and a Tg of 62 ° C.

Synthesis Example 2 Polyoxypropylene (2.2) -2,2-bis (4-)
725 g of hydroxyphenyl) propane, 165 g of polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 500 g of terephthalic acid, 130 g of isododecenyl succinic anhydride, and triisopropyl 1,2,4-benzenetricarboxylic acid. 170 g was added to the flask along with the esterification catalyst. These were reacted with the same equipment and the same formulation as in Synthesis Example 1 to give an acid value of 0.5 KO.
A polyester resin B having a Hmg / g, a hydroxyl value of 25.0 KOHmg / g, a softening point of 109 ° C. and a Tg of 63 ° C. was obtained.

Synthesis Example 3 Polyoxypropylene (2.2) -2,2-bis (4-)
650 g of hydroxyphenyl) propane, 650 g of polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 515 g of isophthalic acid, 70 g of isooctenylsuccinic acid, 80 g of 1,2,4-benzenetricarboxylic acid It was added to the flask together with the oxidization catalyst. These were reacted with the same apparatus and the same formulation as in Synthesis Example 1 to give an acid value of 19.5 KOHmg / g and a hydroxyl value of 3
A polyester resin C having 5.0 KOHmg / g, a softening point of 110 ° C. and a Tg of 60 ° C. was obtained.

Synthesis Example 4 Polyoxypropylene (2.2) -2,2-bis (4-)
Ester of 714 g of hydroxyphenyl) propane, 663 g of polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 648 g of isophthalic acid, 150 g of isooctenylsuccinic acid and 100 g of 1,2,4-benzenetricarboxylic acid It was added to the flask together with the oxidization catalyst. These were reacted with the same apparatus and the same formulation as in Synthesis Example 1 to give an acid value of 21.0 KOHmg / g, a hydroxyl value of 24.0 KOHmg / g, a softening point of 128 ° C. and a Tg of 65.
C. Polyester resin D was obtained.

(Synthesis Example of Polyol Resin) Synthesis Example 1 378.4 g of low molecular weight bisphenol A type epoxy resin (number average molecular weight: about 360) was placed in a separable flask equipped with a stirrer, thermometer, nitrogen inlet, and cooling tube. High molecular weight bisphenol A type epoxy resin (number average molecular weight: about 270
0) 86.0 g, glycidyl compound of bisphenol A-type propylene oxide adduct (n + m in the general formula (II): about 2.1) 191.0 g, bisphenol F
274.5 g, p-cumylphenol 70.1 g, and xylene 200 g were added. 70-100 ° C under nitrogen atmosphere
The temperature is raised to 0.1839 g of lithium chloride, the temperature is further raised to 160 ° C., and xylene is removed under reduced pressure to obtain 180
Polymerization is carried out at a reaction temperature of ℃ for 7 to 9 hours to give an acid value of 0.0KO.
A polyol resin A having a Hmg / g, a hydroxyl value of 70.0 KOHmg / g, a softening point of 110 ° C. and a Tg of 62 ° C. was obtained.

Synthesis Example 2 Using the apparatus of Synthesis Example 1, 205.3 g of low molecular weight bisphenol A type epoxy resin (number average molecular weight: about 360),
High molecular weight bisphenol A type epoxy resin (number average molecular weight: about 3000) 54.0 g, glycidylated bisphenol A type propylene oxide adduct (n + m in the general formula (II): about 2.2) 432.0 g, bisphenol F282 0.7 g, p-cumylphenol 2
6.0 g and xylene 200 g were added. In a nitrogen atmosphere, the temperature is raised to 70 to 100 ° C., and lithium chloride is added to 0.183.
g, further heated to 160 ° C., and stripped of xylene under reduced pressure, and polymerized at a reaction temperature of 180 ° C. for 6 to 8 hours to give an acid value of 0.0 KOHmg / g and a hydroxyl value of 58.0 KOHmg.
/ G, softening point 105 ° C, Tg 58 ° C polyol resin B
Got

(Synthesis Example of Styrene Acrylic Resin) Synthesis Example 1 200 parts by mass of cumene was placed in a reactor, the temperature was raised to the reflux temperature, 75 parts of styrene monomer and 25 parts of n-butyl acrylate were added, and ditertiary butyl peroxide was added. Polymerization was carried out for 4 hours using oxide as an initiator. Then remove cumene,
Acid value 20 KOHmg / g, softening point 110 ° C, Tg 64 ° C
Styrene acrylic resin A was obtained.

(Production Example of Masterbatch Pigment) Production Example 1 Binder resin: Polyester resin A 60 parts Colorant: Carmine 6B magenta pigment (CI Pigment Red 57: 1) 40 parts Auxiliary agent: water 30 parts After mixing with a Henschel mixer, the roll surface temperature is set to 110 ° C by two rolls
Knead for minutes, then pulverize with a pulverizer,
A masterbatch pigment A having a weight average diameter of 1.2 mm was obtained.

Production Example 2 Binder resin: Polyester resin B 60 parts Colorant: Carmine 6B type magenta pigment (CI Pigment Red 57: 1) 40 parts Auxiliary agent: Water 30 parts After mixing the above raw materials with a Henschel mixer, Roll surface temperature is set to 110 ° C by two rolls, 30
Knead for minutes, then pulverize with a pulverizer,
A masterbatch pigment B having a weight average diameter of 1.2 mm was obtained.

Production Example 3 Binder resin: Polyester resin C 60 parts Colorant: Carmine 6B type magenta pigment (CI Pigment Red 57: 1) 40 parts Auxiliary agent: Water 30 parts After mixing the above raw materials with a Henschel mixer, Roll surface temperature is set to 110 ° C by two rolls, 30
Knead for minutes, then pulverize with a pulverizer,
A masterbatch pigment C having a weight average diameter of 1.2 mm was obtained.

Production Example 4 Binder resin: Polyester resin D 60 parts Colorant: Carmine 6B type magenta pigment (CI Pigment Red 57: 1) 40 parts Auxiliary agent: Water 30 parts After mixing the above raw materials with a Henschel mixer, Roll surface temperature is set to 110 ° C by two rolls, 30
Knead for minutes, then pulverize with a pulverizer,
A masterbatch pigment D having a weight average diameter of 1.2 mm was obtained.

Production Example 5 Binder resin: Polyol resin A 60 parts Colorant: Carmine 6B type magenta pigment (CI Pigment Red 57: 1) 40 parts Auxiliary agent: Water 30 parts After mixing the above raw materials with a Henschel mixer, Roll surface temperature is set to 110 ° C by two rolls, 30
Knead for minutes, then pulverize with a pulverizer,
A masterbatch pigment E having a weight average diameter of 1.2 mm was obtained.

Production Example 6 Binder resin: Polyol resin B 60 parts Colorant: Carmine 6B magenta pigment (CI Pigment Red 57: 1) 40 parts Auxiliary agent: Water 30 parts After mixing the above raw materials with a Henschel mixer, Roll surface temperature is set to 110 ° C by two rolls, 30
Knead for minutes, then pulverize with a pulverizer,
A masterbatch pigment F having a weight average diameter of 1.2 mm was obtained.

Production Example 7 Binder resin: Styrene acrylic resin A 60 parts Colorant: Carmine 6B magenta pigment (CI Pigment Red 57: 1) 40 parts Auxiliary agent: water 30 parts After mixing the above raw materials with a Henschel mixer , 30 by 2 rolls with roll surface temperature set to 110 ℃
Knead for minutes, then pulverize with a pulverizer,
A masterbatch pigment G having a weight average diameter of 1.2 mm was obtained.

Production Example 8 Binder resin: Polyester resin A 60 parts Colorant: Quinacridone type magenta pigment (CI Pigment Red 122) 40 parts Auxiliary agent: Water 30 parts After mixing the above raw materials with a Henschel mixer, roll surface temperature 30 by 2 rolls set to 110 ℃
Knead for minutes, then pulverize with a pulverizer,
A masterbatch pigment H having a weight average diameter of 1.2 mm was obtained.

Example 1 Binder resin: Polyester resin A 95 parts Colorant: Masterbatch pigment A 10 parts Charge control agent: Resin charge control agent A 3 parts After mixing the above raw materials with a Henschel mixer,
Melt kneading was carried out by a twin-screw kneader heated to 0 ° C. The kneaded product was cooled with water, coarsely pulverized with a cutter mill, pulverized with a fine pulverizer using a jet stream, and then toner particles were obtained using an air classifier.

Toner particles: 100 parts Additive: Silica (hexamethyldisilazane surface-treated product, average primary particle size: 0.012 μm) 2.4 parts Titania (isobutyltrimethoxysilane surface-treated product, average primary particle size: 0.015 μm) 0.8 part Further, the above toner particles and additives were mixed with a Henschel mixer so that the peripheral speed of the tip of the stirring blade was 40 m / sec, and the mixture was mixed for 360 seconds, after which the mesh was further opened. A 100 μm sieve was used for air sieving, and the weight average diameter was 6.5.
Toner T1 of Example 1 having a size of μm was obtained.

Example 2 In Example 1, the peripheral speed of the tip of the stirring blade at the time of mixing the additive was 30 m.
/ Sec, except that the mixing time was changed to 300 seconds, a toner T2 of Example 2 having a weight average diameter of 6.3 μm was obtained in the same manner as in Example 1.

Example 3 The weight average diameter was 6. In the same manner as in Example 1 except that the amount of silica added was changed to 1.8 parts and the amount of titania added was changed to 0.6 part. 8 μm of Toner T3 of Example 3 was obtained.

Example 4 In Example 1, the titania as an additive was added in an average primary particle size of 0.0
Example 1 except that the surface-treated product of 31 μm n-butyltrimethoxysilane was changed and the addition amount was also changed to 1.2 parts.
In the same manner as described above, Toner T4 of Example 4 having a weight average diameter of 6.4 μm was obtained.

Example 5 The procedure of Example 1 was repeated except that the binder resin was changed to the polyester resin B and the colorant was changed to the masterbatch pigment B, and the weight average diameter was 6.8 μm. Toner T5 of Example 5 was obtained.

Example 6 In the same manner as in Example 1, except that the binder resin was changed to the polyester resin C and the colorant was changed to the masterbatch pigment C, the weight average diameter was 6.5 μm. Toner T6 of Example 6 was obtained.

Example 7 In the same manner as in Example 1 except that the polyester resin D was used as the binder resin and the masterbatch pigment D was used as the colorant, the weight average diameter was 6.6 μm. Toner T7 of Example 7 was obtained.

Example 8 The procedure of Example 1 was repeated except that the binder resin was changed to the polyol resin A and the colorant was changed to the masterbatch pigment E, and the weight average diameter was 6.9 μm. Example 8
Toner T8 was obtained.

Example 9 The procedure of Example 1 was repeated except that the binder resin was changed to the polyol resin B and the colorant was changed to the masterbatch pigment F, and the weight average diameter was 6.4 μm. Example 9
Toner T9 was obtained.

Example 10 The weight average diameter was 6.8 μm in the same manner as in Example 1 except that the charge control agent was changed to the resin charge control agent B in Example 1.
m of Toner T10 of Example 10 was obtained.

Example 11 The weight average diameter was 6.4 μm in the same manner as in Example 1 except that the resin charge control agent C was used instead of the charge control agent.
m of Toner T11 of Example 11 was obtained.

Example 12 The weight average diameter was 6.7 μm in the same manner as in Example 1 except that the resin charge control agent D was used instead of the charge control agent.
m of Toner T12 of Example 12 was obtained.

Example 13 The weight average diameter was 6.2 μm in the same manner as in Example 1 except that the resin charge control agent E was used instead of the charge control agent.
m of the toner T13 of Example 13 is obtained.

Example 14 The weight average diameter was 6.5 μm in the same manner as in Example 1 except that the resin charge control agent F was used instead of the charge control agent.
m of Toner T14 of Example 14 was obtained.

Example 15 The weight average diameter was 6.6 μm in the same manner as in Example 1 except that the resin charge control agent G was used instead of the charge control agent.
m of Toner T15 of Example 15 was obtained.

Comparative Example 1 In Example 1, the peripheral speed of the stirring blade tip at the time of mixing the additive was 15 m.
A toner T16 of Comparative Example 1 having a weight average particle diameter of 6.7 μm was obtained in the same manner as in Example 1 except that the toner T16 was changed to / sec.

Comparative Example 2 The weight average diameter was 7.2 in the same manner as in Example 1 except that the mixing time at the time of mixing the additives was changed to 60 seconds.
Toner T17 of Comparative Example 2 having a size of μm was obtained.

Comparative Example 3 In Example 1, the peripheral speed of the stirring blade tip at the time of mixing the additive was 48 m.
Toner T18 of Comparative Example 3 was obtained in the same manner as in Example 1, except that the toner was changed to / sec.

Comparative Example 4 The weight average particle diameter was 6.5 μm in the same manner as in Example 1 except that the binder resin was changed to styrene acrylic resin A and the colorant was changed to masterbatch pigment G. Toner T19 of Comparative Example 4 was obtained.

Comparative Example 5 The weight average diameter was 6.6 μm in the same manner as in Example 1 except that the masterbatch pigment H was used as the colorant.
m of the toner T20 of Comparative Example 5 was obtained.

Comparative Example 6 Toner T of Comparative Example 6 having a weight average diameter of 6.6 μm was obtained in the same manner as in Example 1 except that the charge control agent was changed to the chromium compound of ditertiarybutylsalicylic acid.
I got 21.

With respect to the magenta toners of Examples and Comparative Examples obtained at this time, the release rate of the additive was measured. The results at this time are shown in Table 1.

[0194]

[Table 1] When two or more different types of additives were used, the average release rate of all additives was calculated from the release rate of each additive and the addition amount at that time.

(Production Example of Carrier) Core material: Cu—Zn ferrite particles (weight average diameter: 45 μm) 5000 parts Coating material: Toluene 450 parts Silicone resin SR2400 (manufactured by Toray Dow Corning Silicone, non-volatile content 50%) 450 Part Aminosilane SH6020 (manufactured by Toray Dow Corning Silicone) 10 parts carbon black 10 parts The above coating material is dispersed with a stirrer for 10 minutes to prepare a coating solution, and the coating solution and the core material are placed in a fluidized bed in a rotary bottom plate disk. The coating liquid was applied to the core material, which was provided with a stirrer and a stirring blade to perform coating while forming a swirling flow. Further, the obtained carrier is baked in an electric furnace at 250 ° C. for 2 hours to give a film thickness of 0.5 μm.
Got a career.

(Manufacturing Example of Developer) 5 parts of each of the toners of these Examples and Comparative Examples and 95 parts of the carrier of the above manufacturing example were mixed by a tumbler mixer to prepare a two-component developer having a toner concentration of 5%. Obtained.

[Evaluation Method] The toner and the two-component developer of these Examples and Comparative Examples were set in the image forming apparatus shown in FIG.
The sheets were continuously copied, and the following various evaluations were performed. Then, the following criteria were used to rank in 5 stages. The results at this time are shown in Table 2. ◎: Very good level ○: Good level □: General level Δ: Practically no problem level ×: Practical problem level

(Durability) The durability was evaluated by measuring the image density of a solid portion with the passage of time using X-Rite 938, and
The evaluation was made based on the degree of reduction in image density with respect to the initial image density after continuous copying of 000 sheets. Here, it is indicated that the lower the image density with respect to the initial image density, the lower the durability.

(Soil Contamination) Evaluation of scumming is carried out at the initial stage, 50,
After continuously copying 000 sheets, the toner existing in the non-image area on the photoconductor is transferred to the tape, and the image density of the tape is changed to X.
The degree of occurrence of background stain was evaluated by measuring with Rite 938, and then obtaining the difference from the image density of the untransferred tape. Here, the larger the difference in image density, the more severe the background stain.

(Toner Scattering) To evaluate the toner scattering, the degree of toner scattering in the image forming apparatus was visually evaluated at the initial stage and after continuous copying of 50,000 sheets.

(Filming) The evaluation of filming is as follows.
After continuous copying of 50,000 sheets, the degree of filming of the photosensitive member, the intermediate transfer member and the like was visually evaluated.

(Transparency) The transparency was evaluated using the image forming apparatus shown in FIG. 1, and an OHP sheet (TYPE PPC-DX, manufactured by Ricoh Elemex Co., Ltd.) was used as a transfer paper.
In addition, a solid image with an adhesion amount of 1.00 ± 0.05 mg / cm ² was created under the following fixing conditions, and the haze degree of the solid image at this time was measured by a direct reading haze computer HGM-2DP manufactured by Suga Test Instruments Co., Ltd. Measured according to the mold, the following criteria,
It was carried out by ranking in 5 steps. This haze degree is also referred to as haze and is measured as a measure of the transparency of the toner. The lower the value, the higher the transparency and the better the color developability when OHP is used. Fixing machine linear speed: 90 ± 2 mm / sec Fixing nip width: 10 ± 1 mm Fixing roller temperature: 160 ± 2 ° C. ◎: Less than 20% ○: 20-25% □: 25-30% Δ: 30-35% ×: 35% or more

(Color Reproducibility) To evaluate the color reproducibility, the image forming apparatus shown in FIG. 1 was used, and transfer paper (TYPE 6) was used.
000 <70W>, manufactured by Ricoh Co., Ltd.)
A solid image of ± 0.05 mg / cm ² was created under the following fixing conditions, and the saturation (C ^* ) of the solid image at this time was determined by X-Ri.
It was measured by te938 and ranked by 5 levels according to the following criteria. Here, the higher the saturation, the better the color reproducibility. Fixing machine linear speed: 180 ± 2 mm / sec Fixing nip width: 10 ± 1 mm Fixing roller temperature: 160 ± 2 ° C .: 76 or more ○: 72 to 76 □: 68 to 72 Δ: 64 to 68 ×: less than 64

(Transfer unevenness / white spots) The transfer unevenness / white spots are evaluated in the initial stage and after continuous copying of 50,000 sheets, and then transfer unevenness / white spots in the image after continuously outputting ten A3 size solid images. The degree of omission was visually evaluated.

[0205]

[Table 2]

[0206]

According to the present invention as described above, in particular, the fluidity and the uniform dispersibility of the magenta colorant are excellent, the background stain and the toner scattering do not occur, and further, the filming on the photoreceptor or the like In the case of a component developer, the occurrence of spent on the carrier is small, and further, image defects such as transfer unevenness and white spots are not seen, and transparency, coloring degree and color reproducibility are further excellent. Provided are a magenta toner for electrophotography, a developer, and an image forming apparatus capable of obtaining stable image quality for a long time even when a toner having a small particle diameter is used.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a copying machine according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of the printer unit according to the embodiment of the present invention.

FIG. 3 is a partially enlarged sectional view of the tandem image forming apparatus according to the embodiment of the present invention.

FIG. 4 is a perspective view showing a layout of a photosensitive drum and its adjacent member according to the embodiment of the present invention.

FIG. 5 is a perspective view showing a recovery screw in the photoconductor cleaning device according to the embodiment of the present invention.

[Explanation of symbols]

10 Intermediate Transfer Belts 14, 15, 16 Support Roller 17 Belt Cleaning Device 18, 18Bk, 18Y, 18M, 18C Image Forming Unit 20 Tandem Image Forming Device 21 Exposure Device 22 Secondary Transfer Device 23 Secondary Transfer Roller 24 Secondary Transfer Belt 25 Fixing Device 27 Pressure Roller 28 Transfer Paper Reversing Device 30 Original Plate 32 Contact Glass 33 First Traveling Body 34 Second Traveling Body 35 Imaging Lens 36 Reading Sensor 40, 40Bk, 40Y, 40M, 40C Photosensitive Drum 42, 50 Paper feeding roller 43 Paper bank 44 Paper feeding cassette 45, 52 Separation roller 46, 48, 53 Paper feeding path 47 Conveying roller 49 Registration roller 51 Manual feed tray 56 Discharging roller 57 Discharging tray 60 Charging device 61, 61Bk, 61Y, 61M, 61C developing unit (developing device) 62 1 Transfer device (transfer roller) 63, 63Bk, 63Y, 63M, 63C Photoconductor cleaning device 64 Static eliminator 65 Development sleeve 66 Stirring part 67 Development part 68 Screw 69 Partition plate 70 Development case 71 Toner concentration sensor 72 Magnet 73 Doctor blade 74 Conductivity Characteristic roller 75 cleaning blade 76 fur brush 77 electric field roller 78 scraper 79 recovery screw 80 toner recycling device 81 pins 82, 87 roller portion 83 recovered toner transport member 84 elongated hole 85 blade 86 rotating shaft 88 transport path case 89 cartridge case 90, 91 Fur brushes 92, 93 Metal rollers 94, 95 Power sources 96, 97 Blade 100 Printer unit (copying device main body) 200 Paper feeding unit (paper feeding table) 300 Scanner unit 400 Document feeder (Automatic document feeder) L laser writing light

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 9/09 G03G 9/08 333 9/10 361 331 (72) Inventor Osamu Uchinokura Nakata, Ota-ku, Tokyo Magome 1-chome 3-6 F-term in Ricoh Co., Ltd. (reference) 2H005 AA01 AA06 AA08 AA21 CA07 CA08 CA22 CB07 CB13 DA02 EA03 EA07 EA10 FA02

Claims (7)

[Claims] 1. At least a binder resin, a magenta colorant,
In an electrophotographic magenta toner obtained by adding an additive to toner particles containing a charge control agent, the binder resin is a polyester resin and / or a polyol resin, and the magenta colorant has the following general formula (I ), Wherein the charge control agent is (a) a sulfonate group-containing monomer, (b) an aromatic monomer having an electron-withdrawing group, (c) an acrylic acid ester monomer and / or a methacrylic acid ester monomer. , And (d) an aromatic vinyl monomer, or a resin charge control agent having (a), (b), and (c) as a constituent unit, and the additive is at least silica and / or titania. Further, a magenta toner for electrophotography, wherein the release rate of the additive of the toner is 0.3 to 4%. [Chemical 1] (In the formula, R ¹ and R ² may be the same or different,
At least one selected from the group consisting of hydrogen atom, alkyl group, phenyl group and halogen atom, and M is B
It is one of a, Ca, Sr, Mn, and Mg. ) Wherein the apparent viscosity by a flow tester of the resin charge controlling agent is ^{10 4 P (10 4 P =} 10 4 g / cm ·
The magenta toner for electrophotography according to claim 1, wherein the temperature of s) is 85 to 110 ° C. 3. The magenta toner for electrophotography according to claim 1, wherein the resin charge control agent is contained in an amount of 0.1 to 20 mass% with respect to the toner particles. 4. The repeating unit of the (a) sulfonic acid group-containing monomer is 1 to 3 relative to the mass of the resin charge control agent.
0% by mass, the repeating unit of the aromatic monomer having the electron-withdrawing group (b) is 1 with respect to the mass of the resin charge control agent.
To 80% by mass, the repeating unit of the (c) acrylic acid ester monomer and / or the methacrylic acid ester monomer is 10 to 80% by mass with respect to the mass of the resin charge control agent, and the repeating of the (d) aromatic vinyl monomer. The magenta toner for electrophotography according to claim 1, wherein a unit is contained in a proportion of 0 to 30% by mass with respect to the mass of the resin charge control agent. 5. A two-component developer using the magenta toner for electrophotography according to claim 1 and a carrier. 6. A container containing the magenta toner for electrophotography according to any one of claims 1 to 4 or the two-component developer according to claim 5. 7. An image forming apparatus for developing an electrostatic latent image formed on a latent image carrier, wherein the container according to claim 6 is loaded.