JP4165822B2 - Full color toner kit, process cartridge, image forming method and image forming apparatus - Google Patents

Description

  The present invention relates to a toner used in a recording method such as an electrophotographic method, an electrostatic recording method, and a toner jet recording method, and further relates to a full color toner kit, a process cartridge, and an image forming apparatus.

  Conventionally, many proposals have been made regarding magnetic toner. For example, Patent Document 1 proposes a developing method using an electrically conductive magnetic toner. In this method, a conductive magnetic toner is supported on a cylindrical conductive sleeve having magnetism inside, and this is brought into contact with an electrostatic image for development. At this time, a conductive path is formed by toner particles between the surface of the recording member and the sleeve surface in the developing unit, and electric charges are guided from the sleeve to the toner particles through this conductive path, and between the image part of the electrostatic image. The toner particles adhere to the image area and are developed by the Coulomb force. The developing method using the conductive magnetic toner is an excellent method that avoids the problems associated with the conventional two-component developing method. However, since the toner is conductive, the developed image is transferred from the recording medium to plain paper or the like. There is a problem that it is difficult to electrostatically transfer to the final support member.

As a developing method using a high-resistance magnetic toner that can be electrostatically transferred, there is a developing method using dielectric polarization of toner particles. However, this method has problems such as a slow development speed and insufficient density of the developed image, and is difficult in practical use.
As another developing method using a high-resistance insulating magnetic toner, the toner particles are frictionally charged by friction between the toner particles, friction between the toner particles and the sleeve, and the like, and then contact the electrostatic image holding member. A developing method is known. However, this method requires less contact between the toner particles and the friction member, and the magnetic toner used has a large amount of magnetic material exposed on the surface of the toner particles. There were problems such as.

Further, a jumping development method is proposed in Patent Document 2 and the like. This involves applying a very thin magnetic toner on the sleeve, tribocharging it, and then developing it very close to the electrostatic image. This method is an excellent method in that the magnetic toner is thinly applied on the sleeve, thereby increasing the chance of contact between the sleeve and the toner and enabling sufficient frictional charging.
However, the developing method using the insulating magnetic toner has unstable elements related to the insulating magnetic toner to be used. This is because a considerable amount of fine powdery magnetic material is mixed and dispersed in the insulating magnetic toner, and a part of the magnetic material is exposed on the surface of the toner particles. As a result, various characteristics required for the magnetic toner, such as development characteristics and durability of the magnetic toner, are changed or deteriorated.

  When the magnetic toner containing the conventional magnetic body is used, the above-mentioned problem occurs because the magnetic body is exposed on the surface of the magnetic toner. That is, by exposing magnetic fine particles having a relatively low resistance compared to the resin constituting the toner to the surface of the magnetic toner, the toner charging performance is lowered, the toner fluidity is lowered, and a long-term In use, toner deterioration such as a decrease in image density due to peeling of the magnetic material due to rubbing between the toners or the regulating member, or generation of shading unevenness called sleeve ghost is caused.

  Conventionally, proposals regarding magnetic iron oxide contained in magnetic toners have been made, but there are still points to be improved. For example, Patent Document 3 proposes a magnetic toner containing magnetic iron oxide containing silicon element. Such magnetic iron oxide intentionally has silicon element present inside the magnetic iron oxide, but still has a point to be improved in the fluidity of the magnetic toner containing magnetic iron oxide.

  Patent Document 4 proposes to control the shape of magnetic iron oxide to be spherical by adding silicate. The magnetic iron oxide obtained by this method uses silicate to control the particle shape, so that a large amount of silicon element is distributed inside the magnetic iron oxide, and the amount of silicon element present on the magnetic iron oxide surface is small. Since the smoothness of the magnetic iron oxide is high, the fluidity of the magnetic toner is improved to some extent, but the adhesion between the binder resin constituting the magnetic toner and the magnetic iron oxide is insufficient.

  Further, Patent Document 5 proposes a method for producing triiron tetroxide by adding a hydrosilosilicate solution during the oxidation reaction to triiron tetroxide. Although the iron tetroxide by this method has Si element near the surface, the Si element exists in a layer near the iron tetroxide surface, and the surface is weak against mechanical impact such as friction. Has a point.

  On the other hand, conventionally, a toner is manufactured as a toner having a desired particle size by melting and mixing a binder resin, a colorant, and the like, uniformly dispersing, pulverizing with a fine pulverizer, and classifying with a classifier. However, there is a limit to the range of materials that can be used to reduce the toner particle size. For example, the resin colorant dispersion must be sufficiently brittle and capable of being finely pulverized by an economically usable production apparatus. From this requirement, in order to make the resin colorant dispersion brittle, when the resin colorant dispersion is actually finely pulverized at a high speed, particles having a wide particle size range are easily formed, and in particular, a relatively large proportion of fine particles ( There arises a problem that excessively pulverized particles) are included therein. Further, such highly brittle materials are often further pulverized or powdered when used as developing toners in copying machines and the like.

  Also, in the pulverization method, it is difficult to completely disperse solid fine particles such as magnetic powder or colorant into the resin, and depending on the degree of dispersion, fogging may increase and image density may decrease. . Furthermore, the pulverization method inherently exposes the magnetic iron oxide particles on the surface of the toner, so that problems still remain in the fluidity of the toner and the charging stability in a harsh environment. That is, in the pulverization method, there is a limit to finer toner particles required for high definition and high image quality, and accordingly, powder characteristics, particularly toner uniform chargeability and fluidity, are significantly attenuated.

In order to overcome the problems of the toner by the pulverization method as described above, and to satisfy the above-described requirements, Patent Document 6, Patent Document 7 and Patent Document 8 include various types of toner including suspension polymerization method toner. A method for producing a toner by a polymerization method has been proposed. For example, in a toner by suspension polymerization, a polymerizable monomer, a colorant (magnetic material), a polymerization initiator, and, if necessary, a crosslinking agent, a charge control agent, and other additives are uniformly dissolved or dispersed. After preparing the monomer composition, the monomer composition is dispersed in a continuous phase containing a dispersion stabilizer, for example, an aqueous phase using a suitable stirrer, and simultaneously subjected to a polymerization reaction to obtain a desired composition. Toner particles having a particle size are obtained.

  Since this toner manufacturing method does not include a pulverization process at all, the toner does not need to be brittle, and a soft material can be used as a resin. The particle size distribution of the toner to be obtained is relatively sharp and the classification step can be omitted, or even if classification is performed, the toner can be obtained in high yield. Further, since a large amount of a low softening point substance can be encapsulated in the toner as a release agent, there is an advantage that the obtained toner has excellent offset resistance. Furthermore, since the obtained toner has a spherical shape, it has excellent fluidity and is advantageous for high image quality.

However, when the polymerized toner contains a magnetic substance, its fluidity and charging characteristics are significantly lowered. This is because magnetic particles are generally hydrophilic, and thus magnetic particles are likely to be present on the toner surface due to the influence of an aqueous dispersion medium when magnetic toner is produced. It is important to improve the surface characteristics of the magnetic material.
Many proposals have been made regarding surface modification for improving the dispersibility of a magnetic substance in a polymerized toner. For example, Patent Document 9, Patent Document 10, Patent Document 11, Patent Document 12, and the like have proposed various silane coupling agent treatment techniques for magnetic materials. In Patent Document 13 and Patent Document 14, silicon element-containing magnetic particles are used. A technique for treating with a silane coupling agent is disclosed.

  However, although the dispersibility in the toner is improved to some extent by these treatments, there is a problem that it is difficult to uniformly hydrophobize the surface of the magnetic material. Generation of magnetic particles cannot be avoided, which is insufficient to improve the dispersibility in the toner to a good level, and it is possible to completely prevent the magnetic material from being exposed to the toner surface. There wasn't.

The polymerized toner is characterized by being easy to take a spherical shape. If a substance with high hardness such as a magnetic substance is exposed on the toner surface, all the exposed magnetic substances have an effect of polishing other things (in the pulverized magnetic toner, in the toner depressions). Some magnetic materials do not have a polishing force for others). Therefore, it can be said that the magnetically polymerized toner tends to deteriorate particularly in various devices that come into contact with the toner. Among them, the photoreceptor is extremely deteriorated. The toner is strongly pressed against the photoconductor by the cleaning blade. When the toner has a magnetic material exposed on the surface, the surface of the photoconductor is scraped by the magnetic material when the toner is strongly pressed against the photoconductor. As a result, compared with non-magnetic toner, the toner having a magnetic material exposed on the surface has a problem that the surface of the photoconductor is frequently scraped and the life of the photoconductor is shortened.
In particular, in a tandem type full-color image forming apparatus, when the black toner for producing black is a magnetic polymerization toner and the other color toner is a non-magnetic toner, only the photoreceptor of the black toner station deteriorates quickly, The color balance as a full color will be lost.

US Pat. No. 3,909,258 Japanese Patent Laid-Open No. 55-18656 JP 62-279352 A Japanese Patent Publication No. 3-9045 JP 61-34070 A Japanese Patent Publication No. 36-10231 Japanese Patent Publication No. 43-10799 Japanese Patent Publication No. 51-14895 Japanese Patent Laid-Open No. 59-200254 Japanese Patent Laid-Open No. 59-200256 JP 59-200237 A JP 59-224102 A JP-A-63-250660 Japanese Patent Laid-Open No. 10-239897

An object of the present invention is to provide a toner, a full-color toner kit, a process cartridge, and an image forming apparatus that have solved the above-described problems.
That is, an object of the present invention is to provide a toner or a full color toner kit, a process cartridge, and an image forming apparatus in which the color balance as a full color over time is not lost, or the background stain derived from black toner over time does not occur.

The above object is achieved by the present invention described below.
That is, the present invention is used in the same color image forming apparatus for forming a color image on a recording medium, a full-color toner kit comprising at least a yellow toner, magenta toner, cyan toner, and black toner and the toner The black toner is composed of at least a binder resin and a colorant, and the black toner is a spherical polymer toner containing iron oxide and satisfies the following relational expression (1) with respect to other chromatic color toners. This is a full color toner kit .
| Q Color |-| Q Black |> 5 ... Formula (1)
(Q color represents the average value of the triboelectric charge amount of the color toner, and Q black represents the triboelectric charge amount of the black toner.)
As a result of intensive studies, the present inventors need to improve the cleaning property of the black toner using the iron oxide-containing polymer toner in order to maintain the color balance in full color image formation well over time. As a result, they have reached the present invention.

Specifically, polymerized toners using magnetic or non-magnetic iron oxide as a colorant can be completely applied to the toner surface even if the hydrophobicity of iron oxide is improved or the method for producing polymer particles is devised. It is difficult to control the iron oxide not to be exposed.
Therefore, a system of an iron oxide-containing polymerized toner having such properties (the iron oxide-containing polymerized toner has a spherical shape, so that all iron oxide exposed on the surface has an abrasive power with respect to the other). It was necessary to use it properly. In most cases, the iron oxide-containing polymerized toner exhibits such abrasiveness when it is pressed against the photoconductor by a cleaner such as a cleaning blade that is in contact with the photoconductor. Therefore, if the iron oxide-containing polymer toner is easily scraped off from the surface of the photosensitive member by the cleaning blade, the cleaning blade tries to pass through (becomes poor cleaning) and the cleaning blade and the photosensitive member are cleaned. The phenomenon that the iron oxide exposed on the toner surface by the pressing of the blade scrapes the surface of the photoreceptor is suppressed.

The present inventors have found that it is effective to reduce the charge amount of the toner as much as possible so that the toner can be easily scraped off from the photoreceptor by the cleaning blade. This is presumed to be a mechanism in which the electrostatic adhesion between the toner and the photoconductor is reduced by reducing the charge amount of the toner, and the toner is easily scraped by the physical force of the cleaning blade.
As described above, the cleaning performance of black toner using iron oxide-containing polymerized toner is thoroughly improved over the cleaning performance of other color toners. It is considered that the color balance in full-color image formation is not lost over time, and excellent image quality can be maintained.

  By the above solution, the toner of the present invention provides a toner, a full color toner kit, a process cartridge, and an image forming apparatus that can obtain an image free of background stains by reducing the amount of scraping of the photoconductor by the black toner. We were able to.

In addition, it is equipped with a plurality of electrostatic charge image carriers suitably used in the present invention, enabling high-speed response, and being rich in media flexibility (applicable to a wide range of transfer materials such as postcards, cardboard and large-size paper). An example of an image forming apparatus (cleaner system) using an intermediate transfer belt is schematically shown in FIG.
FIG. 1 is a schematic cross-sectional view of a color laser printer which is an embodiment of a color image forming apparatus using an electrophotographic process. This image forming apparatus has one developing device for one electrostatic charge image carrier, and each color toner image sequentially formed on a plurality of electrostatic charge image carriers is an intermediate transfer member. A full-color toner image is formed on the intermediate transfer belt by sequentially transferring the toner images on the intermediate transfer belt so as to overlap each other. In this configuration, without using an intermediate transfer member, a toner image of each color that is sequentially formed on a plurality of electrostatic charge image carriers is sequentially transferred onto a transfer material conveyed by a conveying belt so as to overlap. It may be.
The color laser printer shown in FIG. 1 has a plurality of developing units, and is a four-drum system (in-line) that obtains a full-color print image by once continuously transferring multiple images onto an intermediate transfer belt 60 that is a second image carrier. ) A printer.
In FIG. 1, an endless intermediate transfer belt 60 is suspended from a drive roller 6a, a tension roller 6b, and a secondary transfer counter roller 6c, and rotates in the direction of the arrow in the figure. Four developing units are arranged in series with the intermediate transfer belt 60 corresponding to the respective colors.

Hereinafter, an image forming method will be described.
The photosensitive member 1 disposed in the developing unit (Y) for developing the yellow toner is uniformly charged to a predetermined polarity and potential by the primary charging roller 2 during its rotation process, and then image exposure means (not shown). Receiving image exposure 3 by (color separation / imaging exposure optical system of color original image, scanning exposure system by laser scanning which outputs laser beam modulated in accordance with time series electric digital pixel signal of image information, etc.) As a result, an electrostatic latent image corresponding to the first color component image (yellow component image) of the target color image is formed. Next, the electrostatic latent image is developed with yellow toner, which is the first color, by a first developing device (yellow developing device).

In FIG. 1, the yellow image formed on the photoreceptor 1 enters the primary transfer nip portion with the intermediate transfer belt 60. In the transfer nip portion, a flexible electrode 65 to which a voltage is applied by a primary transfer bias source 69 is brought into contact with and in contact with the back side of the intermediate transfer belt 60. The intermediate transfer belt 60 first transfers yellow at the first color port. The primary transfer residual toner remaining on the photoreceptor 1 is removed by a cleaning device 4 (a cleaning blade, a cleaning roller, a cleaning brush, etc., which contacts the photoreceptor and scrapes off the toner). Next, through the same process as described above, each color of magenta (M), cyan (C), and black (Bk) is sequentially transferred from each photoconductor 1 corresponding to each color at each port, and remains on the photoconductor 1 of each color. The primary transfer residual toner is removed by the cleaning device 4. However, at this time, the primary transfer residual toner is not completely removed from the photosensitive member 1, but has slightly passed between the cleaning device 4 and the photosensitive member 1.
In this case, even if it slips through, if it is a small amount, it will be collected by the developing means and will not become an abnormal image. When the primary transfer residual toner passes between the cleaning device 4 and the photosensitive member 1, the toner is pressed against the photosensitive member 1 by the cleaning blade 4, so that the surface of the photosensitive member 1 is scraped or conversely. The toner component may adhere to the surface of the toner. However, normally, the photoconductor 1 is used at a level where there is no problem with the amount of scraping or filming.

Here, in the present invention, an iron oxide-containing polymer toner is used as the black toner. As described above, this iron oxide-containing polymer toner has a much higher polishing ability than other color toners. Therefore, if used without any ingenuity, the photoreceptor 1 corresponding to the iron oxide-containing polymer toner, which is a black toner, is remarkably fast. The surface is shaved. However, in the photoconductor 1 corresponding to the color toner used in the same manner, the photoconductor drum 1 is slightly scraped or slightly filmed so that it is almost the same as the initial quality. As a result, variations occur in images formed at stations corresponding to the respective colors.
Therefore, in the present invention, the charge amount of the iron oxide-containing polymer toner that is a black toner is set to be lower than that of other color toners. The effect is that the electrostatic adhesion force between the iron oxide-containing polymerized toner and the photoreceptor 1 is reduced, and the toner can be easily scraped off by the cleaning device 4, resulting in the black The primary transfer residual toner can be prevented from slipping through between the cleaning device 4 and the photosensitive member 1, or the amount of toner passing through can be drastically reduced. Further, the amount of abrasion of the photosensitive member 1 is drastically reduced, and a life equal to or longer than that of the photosensitive member 1 corresponding to other color toners can be obtained.

The four-color full-color image formed on the intermediate transfer belt 60 is then collectively transferred to the transfer material P by the secondary transfer roller 63 and melted and fixed by a fixing device (not shown) to obtain a color print image.
The secondary transfer residual toner remaining on the intermediate transfer belt 60 is subjected to blade cleaning by the intermediate transfer belt cleaner 9 to prepare for the next image forming process.
In selecting the material of the transfer belt 60, in order to improve registration at each color port, a material that expands and contracts is not desirable, and a resin-based or metal cored rubber belt or resin + rubber belt is desirable.

The full-color image forming method of the present invention is suitable for an image forming method employing an auto-refresh development method because the developer to be used is very excellent in transferability and stable in long-term use.
An auto-refresh development method that can be used in the present invention will be described with reference to FIG.
FIG. 2 is a schematic cross-sectional view illustrating a configuration of a developing device in which a developer recovery unit for recovering a deteriorated developer is disposed in the image forming apparatus. In a developing device using the auto-refresh development system, when a decrease in toner density due to repeated development is detected, a replenishment developer in which toner and a carrier are mixed from the replenishment developer storage chamber 61 opens a replenishment port 58. Then, the developing device 4 is replenished. The developer (mainly deteriorated carrier) that has been replenished repeatedly and overflows overflows from the developer-side developer discharge port 62 provided in the developing device 5, and is developed from the developer intermediate recovery chamber 63. It is discharged to a developer collecting container (not shown) through the agent collecting auger 64.
In the present invention, when a toner and a carrier are mixed to prepare a replenishment developer for the auto-refresh development method, the mixing ratio of the toner and the toner is 1 to 30 parts by mass with respect to 1 part by mass of the carrier. Good results can be obtained. Within this range, the charge imparting ability of the carrier in the developing tank can be stabilized efficiently.

  FIG. 3 is a schematic cross-sectional view showing the configuration of the process cartridge taken out from the image forming apparatus main body. In the process cartridge 200, the photosensitive member 1 and at least one process unit of the developing device 51, the cleaning device 4, and the charging device 2 are integrally formed into a cartridge. The process cartridge 200 is a main body of the image forming apparatus 100 (for example, a copying machine). , Laser beam printer, etc.).

Next, the toner used in the present invention will be described.
The toner of the present invention contains a wax. The added amount of the wax is preferably 2 to 30 parts by mass, more preferably 5 to 20 parts by mass, still more preferably 8 to 20 parts by mass, and particularly preferably 13 to 20 parts by mass with respect to 100 parts by mass of the binder resin. Good to use.
Compared with the pulverized toner manufacturing method, the polymerized toner manufacturing method is less polar than the binder resin in the polymerized toner manufacturing method compared to the pulverized toner manufacturing method. A large amount of wax can be used, which is particularly effective for the effect of preventing offset during fixing.
When the amount of the wax is less than the lower limit, the offset prevention effect tends to be lowered, and when the upper limit is exceeded, the anti-blocking effect is lowered and the anti-offset effect is easily adversely affected, and drum fusion or sleeve fusion is likely to occur. In the case of a polymerized toner manufacturing method, a toner having a wide particle size distribution tends to be generated.

Since the black toner uses iron oxide as a colorant as a main component, the toner becomes harder than a color toner using an organic colorant, and is easily offset during fixing. Therefore, when the toner contains a wax, there is a means that the black toner adds more wax than the color toner. Furthermore, by increasing the amount of wax in the toner, the chargeability is simultaneously lowered.
Examples of waxes that can be used in the present invention include paraffin waxes, polyolefin waxes, modified products thereof (for example, oxides and grafted products), higher fatty acids, and metal salts thereof, amide waxes, and esters. System waxes.

Examples of the toner colorant used in the present invention include the following.
Further, the iron oxide used in the toner relating to the method for producing the black toner of the present invention may contain an element such as phosphorus, cobalt, nickel, copper, magnesium, manganese, aluminum, silicon, etc. The main component is iron oxide, such as iron oxide, and these are used alone or in combination of two or more. These iron oxides preferably have a BET specific surface area of 2 to 30 m ² / g, particularly 3 to 28 m ² / g, and a Mohs hardness of 5 to 7 by a nitrogen adsorption method.
The shape of iron oxide includes octahedron, hexahedron, spherical shape, needle shape, scale shape, and the like, but those with less anisotropy such as octahedron, hexahedron, spherical shape, and indeterminate shape increase the image density. preferable. These shapes can be confirmed by SEM or the like. The average particle size of iron oxide is preferably 0.01 to 1.0 μm, more preferably 0.05 to 0.5 μm. When the average particle size is less than 0.01 μm, the blackness is remarkably lowered, the coloring power is insufficient as a colorant for black and white toner, and the aggregation of the composite oxide particles becomes strong, so that Tend to deteriorate.
On the other hand, when the average particle size exceeds 1.0 μm, the coloring power becomes insufficient as in the case of a general colorant. In addition, particularly when used as a colorant for small-diameter toner, it is probabilistically difficult to disperse the same number of iron oxide particles in individual toner particles, and the dispersibility tends to deteriorate. The average particle diameter of the iron oxide particles can be measured using a transmission electron microscope. Specifically, a powder sample of the toner to be measured is observed with a transmission electron microscope, and the diameter of 100 iron oxide particles in the field of view is measured to determine the average particle diameter.

In the iron oxide used in the iron oxide-containing polymerized toner that can be produced in the present invention, when the particle surface is hydrophobized, the coupling agent is dispersed in the aqueous medium while dispersing the iron oxide particles to have a primary particle size. It is very preferable to use a method in which the surface treatment is carried out while hydrolysis. This hydrophobic treatment method is less likely to cause coalescence between the iron oxide particles than the treatment in the gas phase, and the repulsive action between the iron oxide particles due to the hydrophobic treatment works, and the iron oxide particles are almost in the state of primary particles. Surface treatment with.
The method of treating the surface of iron oxide particles while hydrolyzing the coupling agent in an aqueous medium does not require the use of a coupling agent that generates gas, such as chlorosilanes and silazanes. In the gas phase, the iron oxide particles can be easily combined with each other, and a highly viscous coupling agent which has been difficult to be treated can be used, so that the hydrophobizing effect is great. Examples of coupling agents that can be used in the surface treatment of iron oxide particles according to the present invention include silane coupling agents and titanium coupling agents.
More preferably used is a silane coupling agent, which has the general formula (4)
Rm-SiYn ......... Formula (4)
[Wherein, R represents an alkoxy group, m represents an integer of 1 to 3, Y represents a hydrocarbon group such as an alkyl group, a vinyl group, a glycidoxy group, or a methacryl group, and n represents an integer of 1 to 3. Show. ].

  For example, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, Examples thereof include trimethylmethoxysilane, hydroxypropyltrimethoxysilane, phenyltrimethoxysilane, n-hexadecyltrimethoxysilane, and n-octadecyltrimethoxysilane.

In particular, formula (5)
_{C p H 2p + 1 -Si- (} OC q H 2q + 1) 3 ......... formula (5)
[In formula, p shows the integer of 2-20, q shows the integer of 1-3. ]
It is preferable to hydrophobize iron oxide particles in an aqueous medium using an alkyltrialkoxysilane coupling agent represented by
When p in the above formula (5) is smaller than 2, the hydrophobization treatment is easy, but it is difficult to sufficiently impart hydrophobicity, and it is difficult to suppress exposure of the iron oxide particles from the toner particles. Become. On the other hand, when p is larger than 20, the hydrophobicity is sufficient, but the coalescence between the iron oxide particles increases, making it difficult to sufficiently disperse the iron oxide particles in the toner. Deteriorating.
On the other hand, when q is larger than 3, the reactivity of the silane coupling agent is lowered and the hydrophobicity is not sufficiently performed.
In particular, p in formula (5) represents an integer of 2 to 20 (more preferably, an integer of 3 to 15), and q represents an integer of 1 to 3 (more preferably, an integer of 1 or 2). A trialkoxysilane coupling agent is preferably used.
The treatment amount is 0.05 to 20 parts by mass, preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the iron oxide particles.

  Furthermore, other colorants may be used in combination with iron oxide. Examples of coloring materials that can be used in combination include magnetic or nonmagnetic inorganic compounds, and known dyes and pigments. Specifically, for example, ferromagnetic metal particles such as cobalt and nickel, or alloys obtained by adding chromium, manganese, copper, zinc, aluminum and rare earth elements to these, particles such as hematite, titanium black, nigrosine dye / pigment , Carbon black, phthalocyanine and the like. These may also be used after treating the surface.

  As the yellow colorant, condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168 or 180 is preferably used. Furthermore, C.I. I. A dye such as Solvent Yellow 93, 162, 163 may be used in combination.

  As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 144, 146, 166, 169, 177, 184, 185, 202 , 206, 220, 221 or 254 are preferably used.

  As the cyan colorant, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds are used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62 or 66 can be particularly preferably used.

  These colorants can be used alone, mixed or in a solid solution state. In the present invention, the colorant is selected in consideration of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. In the toner used in the present invention, the addition amount of the colorant is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.

  As the binder resin used for the toner, the following binder resins can be used. For example, a homopolymer of styrene and its substitute such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, Styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinylethyl Styrene copolymers such as ether copolymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers; polyvinyl chloride; phenol resins ; Naturally modified film Natural resin-modified maleic acid resin; acrylic resin; methacrylic resin; polyvinyl acetate; silicone resin; polyester resin; polyurethane; polyamide resin; furan resin: epoxy resin; xylene resin: polyvinyl butyral; Resin; Petroleum resin can be used. Preferred binder materials include styrene copolymers or polyester resins. A cross-linked styrene resin is also a preferable binder resin.

The styrenic polymer or styrenic copolymer may be cross-linked, or may be a mixed resin of a cross-linked resin and a non-cross-linked resin.
As the crosslinking agent for the binder resin, a compound having two or more polymerizable double bonds may be mainly used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; for example, carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-butadiol dimethacrylate; , Divinyl aniline, divinyl ether, divinyl sulfide, divinyl compounds such as divinyl sulfone; and compounds having three or more vinyl groups are used alone or as a mixture.
As addition amount of a crosslinking agent, 0.001-10 mass parts is preferable with respect to 100 mass parts of polymerizable monomers used for synthesize | combining binder resin.

  The toner of the present invention may contain a charge control agent.

  The following substances are used for controlling the toner to be negatively charged. For example, organometallic compounds and chelate compounds are effective, and monoazo metal compounds, acetylacetone metal compounds, aromatic hydroxycarboxylic acids or their metal compounds, aromatic mono or polycarboxylic acids or their metal compounds are preferably used. Further, phenol derivatives such as bisphenol; urea derivative; boron compound; quaternary ammonium salt; calixarene; silicon compound; styrene-acrylic acid copolymer; styrene-methacrylic acid copolymer; styrene-acrylic-sulfonic acid copolymer Coalescence is mentioned.

  The following substances are used to control the toner to be positively charged. For example, nigrosine; modified product of fatty acid metal salt; guanidine compound; imidazole compound; quaternary ammonium salt such as tributylbenzammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate Lake salts of onium salts such as phosphonium salts and quaternary ammonium salts or onium salts; triphenylmethane dyes and lake lake pigments (for example, phosphotungstic acid, phosphomolybdic acid, phosphotungstic molybdic acid, tannic acid , Lauric acid, gallic acid, ferricyanide, ferrocyanide); metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide Dibutyl tin borate, dioctyl tin borate, such as diorganotin tin borate such dicyclohexyl tin borate, and the like. These can be used alone or in combination of two or more. Among these, a charge control agent such as a nigrosine-based or quaternary ammonium salt is particularly preferably used because it can provide a good rise in charge.

  These charge control agents are used in an amount of 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and still more preferably 0.2 to 4 parts by mass with respect to 100 parts by mass of the binder resin of the toner. Good to do.

  Further, the toner of the present invention can provide better results when an external additive is mixed as necessary. Examples of additives include fluidity improvers such as titanium oxide, silica and alumina, lubricants such as polyfluorinated ethylene and zinc stearate, abrasives such as cerium oxide, silicon carbide and strontium titanate, or carbon such as carbon. Examples thereof include conductivity imparting agents such as black and tin oxide, and fixing aids such as low molecular weight polyethylene. Also, white fine particles having a reverse polarity can be used as a developability improver.

  The toner according to the present invention preferably has a weight average particle diameter D4 of 3.0 to 10.0 μm. If the weight average particle diameter of the toner exceeds 10.0 μm, the toner particles for developing the electrostatic charge image become large. Therefore, even if the magnetic force of the magnetic coat carrier is lowered, development that is faithful to the electrostatic charge image is difficult to be performed. Further, when electrostatic transfer is performed, the toner is likely to be scattered. In addition, a toner having a weight average particle diameter of less than 3 μm has poor handling properties as a powder. In order to measure the particle size distribution of the toner, for example, a method using a Coulter counter can be mentioned.

Further, in the black toner according to the present invention, the ratio (D4 / D1) of the weight average particle diameter D4 and the number average particle diameter D1 is preferably in the following relationship.
1.00 <(D4 / D1) <1.25 Formula (3)
In general, the smaller the (D4 / D1), the sharper the particle size distribution of the toner, and (D4 / D1) is 1 when the toner has a single particle size. In the present invention, by sharpening the particle size distribution of the toner so that (D4 / D1) is less than 1.25, a uniform transfer state can be obtained regardless of the toner particles. As a result, the cleaning margin of the photoconductor is increased, and as a result, the photoconductor can be prevented from being scraped.

The black toner according to the present invention is substantially spherical, but specifically, the average circularity of the toner is preferably 0.97 or more. When the circularity of the toner is 0.97 or more, the transfer rate is remarkably increased, and the cleaning margin of the photosensitive member is increased. As a result, it is possible to suppress the abrasion of the photosensitive member.
Here, the circularity is an index of the degree of unevenness of the toner particles, and indicates 1.00 when the toner is a perfect sphere, and the circularity becomes smaller as the surface shape becomes more complicated. The calculation formula is as follows.
Circularity a = _{L 0} / _L ... (6)
(L ₀ is the circumference of a circle having the same projected area as the particle image, and L is the circumference of the projected image of the particle.)
Next, a method for measuring the circularity will be described.
The circularity can be measured using a flow type particle image analyzer FPIA-1000 manufactured by Toa Medical Electronics. As a specific measuring method, 0.1 to 0.5 ml of a surfactant, preferably alkylbenzene sulfonate is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance, and further measurement is performed. Add about 0.1-0.5g of sample. The suspension in which the sample is dispersed is subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the shape of the toner is measured by the above apparatus with the dispersion concentration being 3000 to 10000 / μl.

Next, a method for producing the toner used in the present invention will be described. The color toner used in the present invention can be manufactured using a pulverized toner manufacturing method and a polymerized toner manufacturing method. On the other hand, the black toner can be manufactured using a polymerization toner manufacturing method.
As the toner according to the present invention, it is preferable to use a polymerized toner from the viewpoints that good transferability and charge amount can be obtained, and that it is easy to maintain a stable full color image quality over a long period of time.

  In the present invention, when a pulverized toner is used, a binder resin, wax, a pigment or dye as a colorant, and if necessary, a charge control agent and other additives are mixed with a mixer such as a Henschel mixer or a ball mill. Mix thoroughly; melt and knead the resulting mixture using a heat kneader such as a heated roll, kneader, extruder, etc., and disperse or melt the metal compound and colorant while the resin components are mutually compatible; The resulting kneaded product is cooled and solidified, and then pulverized and classified to obtain a toner. Further, the toner used in the present invention can be obtained by sufficiently mixing the toner and a desired external additive by a mixer such as a Henschel mixer, if necessary.

  In the present invention, when a polymerized toner is used, for example, a method of obtaining a spherical toner particle by atomizing a molten mixture into air using a disk or a multi-fluid nozzle described in JP-B-56-13945; 36-10231, JP-A-59-53856, and JP-A-59-61842, a monomer composition containing at least a polymerizable monomer, a colorant and a wax is directly polymerized to form toner particles. A method of directly producing toner particles by using the generated suspension polymerization method; a dispersion polymerization method or a water-soluble polarity in which toner particles are directly produced using an aqueous organic solvent which is soluble in the monomer and insoluble in the obtained polymer. Emulsion polymerization method represented by soap-free polymerization method that directly polymerizes in the presence of a polymerization initiator to produce toner particles; It is possible to produce a toner using a hetero aggregation method or the like for the added association polarity particles having a. In addition, a so-called seed polymerization method in which a monomer is further adsorbed to the obtained polymer particles and then polymerized using a polymerization initiator can be suitably used in the present invention.

  When the two-component developer is prepared by mixing the toner and the carrier in the present invention, generally good results are obtained when the mixing ratio is 2 to 15% by mass, preferably 4 to 13% by mass, as the toner concentration in the developer. Is obtained. If the toner concentration is less than 2% by mass, the image density is low and practical use becomes difficult. If the toner concentration exceeds 15% by mass, fogging and in-machine scattering increase, and the useful life of the developer is shortened.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but this does not limit the present invention in any way. In addition, all the parts in the following mixing | blending are a mass part.

<Toner Production Example 1 (polymerized cyan toner)>
450 parts by mass of 0.1M Na ₃ PO ₄ aqueous solution was added to 710 parts by mass of ion-exchanged water, heated to 60 ° C., and then at 12000 rpm using a TK homomixer (manufactured by Special Machine Industries). Stir. To this, 68 parts by mass of 1.0 M CaCl ₂ aqueous solution was gradually added to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .

on the other hand,
·styrene
165 parts by mass / n-butyl acrylate
35 parts by mass I. Pigment Blue 15: 3 (colorant)
15 parts by weight, dialkyl salicylic acid metal compound (charge control agent)
5 parts by mass / saturated polyester (polar resin)
10 parts by mass, ester wax (melting point 70 ° C)
50 parts by mass The above material was heated to 60 ° C., and uniformly dissolved and dispersed at 11000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). In this, 10 parts by mass of a polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was put into an aqueous medium and stirred at 11000 rpm for 10 minutes with a TK homomixer at 60 ° C. in an N ₂ atmosphere to granulate the polymerizable monomer composition. Then, while stirring with a paddle stirring blade, the temperature was raised to 80 ° C. and reacted for 10 hours. After completion of the polymerization reaction, the residual monomer was distilled off under reduced pressure. After cooling, hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) ₂ , followed by filtration, washing with water and drying to obtain cyan toner particles.
To 100 parts by mass of the obtained cyan toner particles, 1.6 parts by mass of hydrophobized silica fine powder (number average particle size of primary particles: 0.03 μm) was externally added to give a weight average particle size of 6.8 μm. A polymerized cyan toner was obtained.

A specific example of toner particle size measurement is shown below.
0.1 to 5 ml of a surfactant (alkylbenzene sulfonate) is added to 100 to 150 ml of the electrolyte solution, and 2 to 20 mg of a measurement sample is added thereto. The electrolytic solution in which the sample is suspended is dispersed for 1 to 3 minutes using an ultrasonic disperser, and the volume is set to 0. 0 on the basis of the volume using an aperture adjusted to an appropriate toner size such as 17 μm or 100 μm using the Coulter counter multisizer described above. The particle size distribution of 3 to 40 μm is measured. The number average particle diameter and weight average particle diameter measured under these conditions were determined by computer processing.

<Toner Production Example 2 (Polymerized Magenta Toner)>
A polymerized magenta toner having a weight average particle diameter of 6.8 μm was obtained in the same manner as in Toner Production Example 1 except that 8 parts by mass of quinacridone was used in place of Pigment Blue used in Toner Production Example 1. .

<Toner Production Example 3 (Polymerized Yellow Toner)>
A polymerized yellow having a weight average particle diameter of 6.8 μm, similar to Toner Production Example 1, except that 6.5 parts by weight of Pigment Yellow 93 was used instead of Pigment Blue used in Toner Production Example 1. A toner was obtained.

<Toner Production Example 4 (Polymerized Black Toner 1)>
(Example of manufacturing surface-treated magnetic material)
An aqueous solution containing ferrous hydroxide was prepared by mixing 1.0 to 1.1 equivalents of a caustic soda solution with respect to iron ions in an aqueous ferrous sulfate solution. While maintaining the pH of the aqueous solution at around 9, air was blown and an oxidation reaction was performed at 80 to 90 ° C. to prepare a slurry liquid for generating seed crystals. Subsequently, after adding ferrous sulfate aqueous solution so that it may become 0.9-1.2 equivalent with respect to the original alkali amount (sodium component of caustic soda) to this slurry liquid, the slurry liquid is maintained at pH 8 and air is supplied. The oxidation reaction was promoted while blowing, and the magnetic iron oxide particles produced after the oxidation reaction were washed, filtered, and taken out once. At this time, a small amount of water-containing sample was collected and the water content was measured. Next, this water-containing sample was re-dispersed in another aqueous medium without drying, and then the pH of the re-dispersed liquid was adjusted to about 6, and the silane coupling agent (n-C10H ₂₁ Si ( 1.0 part of OCH ₃ ) ₃ ) was added to the magnetic iron oxide (the amount of magnetic iron oxide was calculated as a value obtained by subtracting the water content from the water-containing sample), and a coupling treatment was performed. The produced hydrophobic iron oxide particles were washed, filtered and dried by a conventional method, and then the slightly agglomerated particles were pulverized to obtain a surface-treated magnetic body 1.

(Production example of magnetic material)
In the same manner as in Production Example 1 of the surface-treated magnetic material, the magnetic iron oxide particles generated after the oxidation reaction are washed, filtered, dried without surface treatment, and the aggregated particles are crushed. Magnetic material 1 was obtained.

450 parts of a 0.1 M Na ₃ PO ₄ aqueous solution was added to 710 parts of ion-exchanged water, heated to 60 ° C., and then stirred using the apparatus shown in FIGS. 4 and 5 are schematic cross-sectional views showing the configuration of a stirring device that uses polymerized toner for production. To this, 68 parts of 1.0 M CaCl ₂ aqueous solution was added to obtain an aqueous dispersion medium containing a minute water-insoluble dispersant Ca ₃ (PO ₄ ) ₂ .

·styrene
80 parts n-butyl acrylate
20 parts, unsaturated polyester resin
1 part saturated polyester resin
3 parts, negative charge control agent (monoazo dye-based Fe compound)
1 part, surface-treated magnetic material 1
90 parts / ester wax (maximum endothermic peak 72 ° C. in DSC) 6 parts The above formulation was heated to 60 ° C. and uniformly dissolved or dispersed and mixed using a dissolution tank (with a stirrer). A polymerization monomer composition was prepared by dissolving 5 parts of a polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile).
The polymerizable monomer composition was put into the aqueous dispersion medium, and the polymerizable monomer composition was granulated at 60 ° C. in an N 2 atmosphere. The relationship shown in FIGS. 4 and 5 at this time is L / D = 1.3, 1 / L = 0.1, d / D = 0.25.
The relationship between the volume V (m3) in the granulation container and the power P (kW) of the stirring device was P / V = 25.

In addition, when the flow direction of the fluid at this time was confirmed with the high-speed video camera (the Kodak company make, Ekta promotion analyzer HS4540), as shown in FIG. 4, it was attracted | sucked from the upper direction and the downward direction of the stirring chamber, and was injected from the side surface. Was clearly confirmed.
Also, immediately after the polymerizable monomer composition was put into the granulation vessel, the inside of the granulation vessel was confirmed with the above high-speed video camera, and the polymerizable monomer composition was smoothly mixed into the aqueous medium. I was able to confirm.

Ten minutes after charging the polymerizable monomer composition, the stirring device was stopped and transferred to a polymerization tank equipped with a paddle stirring blade. In the polymerization tank, the reaction was carried out for 10 hours at 60 ° C. in an N 2 atmosphere while stirring with a paddle stirring blade. After the completion of the polymerization reaction, the remaining monomer was distilled off under reduced pressure. After cooling, hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) ₂ , followed by filtration, washing with water and drying to obtain colored suspended particles. .
When the particle size distribution of the colored suspended particles was measured with a Coulter Multisizer, the volume average particle size was 6.5 μm and the number variation coefficient was 30%. The number variation coefficient is
Number variation coefficient = [S / D1] × 100 (7)
In the formula (7), S represents the standard deviation in the number distribution of toner particles, and D1 represents the number average diameter (μm) of the toner particles.
That is, the smaller the coefficient of variation, the sharper the particle size distribution of the toner particles, and a larger value indicates a broader particle size distribution. Further, when the toner tomographic plane was observed, a core / shell structure was confirmed.

  100 parts by mass of the toner particles, 0.6 parts by mass of the hydrophobized silica fine powder of toner production example 1 and 1.0 part by mass of hydrophobic titania fine powder having a primary particle size of 15 nm were mixed with a Henschel mixer (Mitsui Miike Chemical Industries, Ltd.). And a mixed black toner 1 having a weight average particle diameter of 6.5 μm was obtained.

<Toner Production Example 5 (Polymerized Black Toner 2)>
Instead of the external additive treatment in Toner Production Example 4, only 1.2 parts by mass of the hydrophobic titania fine powder of Toner Production Example 4 was externally added, and the weight was the same as in Toner Production Example 4. Polymerized black toner 2 having an average particle diameter of 6.5 μm was obtained.

<Toner Production Example 6 (Polymerized Black Toner 3)>
Instead of the external additive treatment in Toner Production Example 4, the weight was the same as in Toner Production Example 4 except that 1.6 parts by mass of the hydrophobized silica fine powder of Toner Production Example 1 was externally added. Polymerized black toner 3 having an average particle diameter of 6.5 μm was obtained.

<Carrier production example 1>
・ Phenol
7.5 parts by mass / formalin solution
11.25 parts by mass (formaldehyde about 40%, methanol about 10%, the rest is water)
・ Magnetite fine particles oleophilicized with 1.0% by mass of γ-glycidoxypropyltrimethoxysilane
62 parts by mass (average particle size 0.24 μm, specific resistance 5 × 105 Ω · cm)
.Alpha.-Fe2O3 fine particles treated with lipophilicity with 1.0 mass% of .gamma.-glycidoxypropyltrimethoxysilane
26 parts by mass (average particle size 0.60 μm, specific resistance 2 × 109 Ω · cm)
The lipophilic treatment of magnetite and α-Fe 2 O 3 used here was performed by adding 1.0 part by mass of γ-glycidoxypropyltrimethoxysilane to 99 parts by mass of magnetite and 99 parts by mass of α-Fe 2 O 3, respectively. This was carried out by premixing and stirring for 30 minutes at 100 ° C. in a Henschel mixer.

  The above materials and 11 parts by mass of water were mixed at 40 ° C. for 1 hour. To this slurry, 2.0 parts by mass of 28% by mass ammonia water as a basic catalyst and 11 parts by mass of water were placed in a flask, heated to 85 ° C. over 40 minutes with stirring and mixing, and reacted for 3 hours. A phenolic resin was produced and cured. Then, after cooling to 30 degreeC and adding 100 mass parts water, the supernatant liquid was removed, the deposit was washed with water, and air-dried. Next, this was dried at 180 ° C. under reduced pressure (5 mmHg or less) to obtain spherical magnetic carrier core particles containing magnetite fine particles using a phenol resin as a binder resin.

Coarse particles are removed from the particles with a 60 mesh and 100 mesh sieve, and then a multi-division wind classifier (Elbow Jet Lab EJ-L-3, manufactured by Nittetsu Mining Co., Ltd.) using the Coanda effect is used. Fine powder removal and coarse powder removal were performed to obtain carrier core particles having a volume average 50% particle size of 35 μm. The obtained carrier core had a specific resistance of 2.2 × 10 ¹² Ω · cm.
Thereafter, 3% by mass of γ-aminopropyltrimethoxysilane A diluted with a toluene solvent was applied to the core surface while continuously applying a shear stress. At that time, it was carried out while volatilizing the solvent at 40 ° C., 100 torr and a dry nitrogen stream. Subsequently, a mixture of 0.5% by mass of a straight silicone resin in which all substituents are methyl groups and 0.015% by mass of γ-aminopropyltrimethoxysilane B was coated with toluene as a solvent. At that time, it was performed while volatilizing the solvent at 40 ° C., 500 torr, and a dry nitrogen stream.

Furthermore, this magnetic coat carrier was baked at 180 ° C., coarse particles aggregated were cut with a 100 mesh sieve, and then fine particles and coarse particles were removed with a multi-division wind classifier to adjust the particle size distribution.
Thereafter, the carrier 1 was obtained by adjusting the humidity at 20 ° C./60% RH for 100 hours in a hopper kept at 23 ° C. and 60%. The physical properties of the obtained carrier 1 are shown in Table 1.

The measuring method of each physical property is described below.
A method for measuring the charge amount of toner and carrier will be described.
The toner and carrier charge amounts are measured by the blow-off method.
FIG. 6 is an explanatory diagram of an apparatus for measuring the tribo charge amount. As a measurement sample, 1.0 g of toner and 19.0 g of magnetic carrier are put in a 50 cc polyethylene container and left open for one day in a normal temperature and humidity environment (23 ° C./50%). What was mixed with a mixer for 600 seconds is used. About 0.3 g (W (g)) of the sample is placed in a metal measuring vessel 212 having a screen 213 having an opening of 20 μm (625 mesh) on the bottom, and a metal lid 214 is placed. At this time, the total weight of the measurement container 212 is weighed and is defined as W1 (g). Next, in the suction machine 211 (at least a part in contact with the measurement container 212 is an insulator), suction is performed from the suction port 217 and the air volume control valve 216 is adjusted to set the pressure of the vacuum gauge 215 to 250 mmAq. In this state, suction is sufficiently performed, preferably for 2 minutes, and the toner is removed by suction. At this time, the potential of the electrometer 219 is set to V (volt). Here, reference numeral 218 denotes a capacitor whose capacity is C (μF). The total weight of the measurement container after suction is weighed and is defined as W2 (g). At this time, the charge amounts (μC / g) of the toner and the carrier are calculated as follows. Incidentally, the triboelectric charge amounts Q color and Q black shown in Tables 1 and 2 are values obtained when measurement was performed using iron powder EFV200 and 300 as standard carriers.
Toner charge amount (mC / kg) = C × V / (W1-W2)
Charge amount of carrier (mC / kg) = − C × V / (W− (W1−W2))
Further, the triboelectric charge amount of the developer toner at the time of durability was measured by sampling 1 g of the developer on the developing sleeve and using the above measuring apparatus without mixing and stirring.

<Example 1>
A carrier 1 and a polymerized yellow toner, a polymerized magenta toner, a polymerized cyan toner, or a polymerized black toner 1 are mixed so that the ratio of the toner to the total mass is 8% by mass, respectively, to produce a two-component developer of four colors. did. Using the commercially available printer IPSiO COLOR 8000 (manufactured by Ricoh), the obtained four-color two-component developer is used to input an original image with a blackening ratio: image DUTY 5%, and print out 40,000 sheets. Evaluation was made on the amount of photoconductor shaving corresponding to each color. The results are shown in Table 1.
Each measurement condition and evaluation criteria are shown below.

  The evaluation environment was performed under high temperature and high humidity (H / H: 32.5 ° C./90% RH). The paper used was a color laser copier SK paper manufactured by Canon Inc., which was conditioned for 24 hours under high temperature and high humidity (H / H: 32.5 ° C./90% RH).

<Example 2>
A carrier 1 and a polymerized yellow toner, a polymerized magenta toner, a polymerized cyan toner, or a polymerized black toner 2 are mixed so that the ratio of the toner to the total mass is 8% by mass, respectively, and a four-component two-component developer is manufactured. did.
The obtained four-color two-component developer was evaluated in the same manner as in Example 1. The results are shown in Table 1.

<Comparative Example 1>
A carrier 1 and a polymerized yellow toner, a polymerized magenta toner, a polymerized cyan toner, or a polymerized black toner 3 are mixed so that the ratio of the toner to the total mass is 8% by mass, thereby producing a two-component developer of four colors. did. The obtained four-color two-component developer was evaluated in the same manner as in Example 1. The results are shown in Table 1.

表１に示すように、実施例１と２では、ブラックトナーの感光体の削れ量が、比較例１と比べて、非常に少ないことがわかる。

As shown in Table 1, in Examples 1 and 2, it can be seen that the amount of black toner photoconductor scraping is much smaller than that in Comparative Example 1.

<Example 3>
Polymerized yellow toner, polymerized magenta toner, polymerized cyan toner, or polymerized black toner 1 is filled in a process cartridge corresponding to each color, and a commercially available printer LBP-2810 (manufactured by Canon Inc.) is used to obtain a blackening rate. : An original image of DUTY 5% was input to produce 20,000 sheets, and the amount of abrasion of the photosensitive member of each color process cartridge was evaluated. The results are shown in Table 2.

<Example 4>
Polymerized yellow toner, polymerized magenta toner, polymerized cyan toner, or polymerized black toner 2 is filled in a process cartridge corresponding to each color, and a commercially available printer LBP-2810 (manufactured by Canon Inc.) is used to obtain a blackening rate. : An original image of DUTY 5% was input to produce 20,000 sheets, and the amount of abrasion of the photosensitive member of each color process cartridge was evaluated. The results are shown in Table 2.

<Comparative example 2>
Polymerized yellow toner, polymerized magenta toner, polymerized cyan toner, or polymerized black toner 3 is filled in a process cartridge corresponding to each color, and a commercially available printer LBP-2810 (manufactured by Canon Inc.) is used to obtain a blackening rate. : An original image of DUTY 5% was input to produce 20,000 sheets, and the amount of abrasion of the photosensitive member of each color process cartridge was evaluated. The results are shown in Table 2.

表２に示すように、実施例３と４では、ブラックトナーの感光体の削れ量が、比較例２と比べて、非常に少ないことがわかる。

As shown in Table 2, in Examples 3 and 4, it can be seen that the amount of black toner photoconductor scraping is much smaller than that in Comparative Example 2.

1 is a schematic cross-sectional view of a color image forming apparatus using an electrophotographic process. FIG. 2 is a schematic cross-sectional view illustrating a configuration of a developing device in which a developer recovery unit for recovering a deteriorated developer is disposed in the image forming apparatus. FIG. 2 is a schematic cross-sectional view illustrating a configuration of a process cartridge taken out from the image forming apparatus main body. It is a schematic sectional drawing which shows the structure of the stirring apparatus which uses a polymerization toner for manufacture. It is a schematic sectional drawing which shows the structure of the stirring apparatus which uses a polymerization toner for manufacture. It is explanatory drawing of the apparatus which measures the amount of tribo charges.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging apparatus 3 Image exposure 4 Cleaning apparatus 5 Developing apparatus 51 Developing sleeve 52 Developer 53 Supply roller 54 Conveying roller 55 Control member 56 Toner 57 Carrier 58 Supply port 61 Replenishment developer storage chamber 62 Developer side developer Discharge port 63 Developer intermediate recovery chamber 64 Developer recovery auger 7 Transfer device 70 Intermediate transfer belt 73 Primary transfer roller 76 Secondary transfer roller 79 Primary transfer bias source 81 Stirring tank 82 Stirring tank lid 83 Dispersing section 84 Stirring rotor shaft 85 Temperature Adjusting medium jacket 86 Motor 87 Control device 91 Stirring rotor shaft 92 Stirring rotor 93 Stirring stator 100 Image forming device 110 Process cartridge 200 Charge amount measuring device 211 Suction machine 212 Measuring container 213 Screen 214 Lid 215 Vacuum gauge 216 Air flow rate adjusting valve 2 17 Suction port 218 Condenser 219 Electrometer P Transfer material

Claims (12)

A full color toner kit comprising at least a yellow toner, a magenta toner, a cyan toner, and a black toner used in the same color image forming apparatus for forming a color image on a recording medium ,
The toner comprises at least a binder resin and a colorant,
The black toner is a spherical polymer toner containing iron oxide and satisfies the following relational expression (1) with respect to other chromatic color toners.
| Q Color |-| Q Black |> 5 ... Formula (1)
(Q color represents the average value of the triboelectric charge amount of the color toner, and Q black represents the triboelectric charge amount of the black toner.)
This is a full color toner kit. The full color toner kit according to claim 1,
The black toner and the color toner satisfy the following relational expression (2).
| Q Color |-| Q Black |> 10 ... Formula (2)
This is a full color toner kit. The full color toner kit according to claim 1 or 2 ,
The full color toner kit , wherein the black toner has an average circularity of 0.97 or more . The full-color toner kit according to any one of claims 1 to 3,
The black toner satisfies the following relational expression (3).
1.00 <(D4 / D1) <1.25 Formula (3)
(Here, D4 is a volume average particle diameter, and D1 is a number average particle diameter.)
This is a full color toner kit. A full-color toner kit according to any one of claims 1 to 4,
A full color toner kit characterized in that the black toner contains more release agent than any color toner . A process cartridge for use in a color image forming apparatus that includes at least a photoreceptor and a developing device and forms a color image on a recording medium;
  The toner cartridge according to any one of claims 1 to 5 is used as the toner in the process cartridge,
  The process cartridge containing black toner and the process cartridge containing color toner have different potential settings on the photoreceptor surface.
  A process cartridge characterized by that. An image carrier that forms an electrostatic latent image by electrostatic charge, a latent image forming unit that exposes the image carrier to form a latent image, and supplies a toner to the latent image on the surface of the image carrier to make a visible image. Development means, transfer means for transferring onto the recording material via an intermediate transfer body that moves on the surface while being in contact with the image carrier, and cleaning for recovering transfer residual toner remaining on the surface of the image carrier after transfer from the image carrier In an image forming apparatus comprising a cleaning unit having a blade,
  For development in the image forming apparatus, the toner kit according to claim 1 is used as toner,
  The potential setting on the surface of the photoreceptor varies depending on the toner to be developed.
  An image forming apparatus. In an image forming method of forming an image using black toner and chromatic color toner,
The black toner and the chromatic toner comprise at least a binder resin and a colorant,
The black toner is a spherical polymer toner containing iron oxide, and satisfies the following relational expression (1) with respect to the chromatic color toner.
| Q Color |-| Q Black |> 5 ... Formula (1)
(Q color represents the average value of the triboelectric charge amount of the color toner, and Q black represents the triboelectric charge amount of the black toner.)
An image forming method. The image forming method according to claim 8,
  The black toner and the color toner satisfy the following relational expression (2).
          | Q Color |-| Q Black |> 10 ... Formula (2)
  An image forming method. The image forming method according to claim 8, wherein:
  Black toner has an average circularity of 0.97 or more.
  An image forming method characterized by that. The image forming method according to any one of claims 8 to 10,
  The black toner satisfies the following relational expression (3).
          1.00 <(D4 / D1) <1.25 Formula (3)
          (Here, D4 is a volume average particle diameter, and D1 is a number average particle diameter.)
  An image forming method. 12. The image forming method according to claim 8, wherein
  Black toner contains more release agent than any color toner
  An image forming method.

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