JPH10333359A - Toner for developing electrostatic charge image and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a toner for developing an electrostatic charge image less liable to cause filming on a photoreceptor and to contaminate the surface of a toner support such as a sleeve or a carrier without deteriorating low-temp. fixability and excellent in anti-offsetting property and durability. SOLUTION: This toner contains at least a bonding resin, a colorant and a releasing agent. The THF-soluble component of the toner has at least one peak in the mol.wt. range of 1,000 to <2,000 and at least one peak in the mol.wt. range of 2,000-300,000 in the mol.wt. distribution by GPC and has a wt. average mol.wt. (Mw) of 90,000-2,000,000. Integrated mol.wt. (T) in a mol.wt. range of >=800, integrated mol.wt. (L) in the mol.wt. range of 2,000-5,000 and integrated mol.wt. (H) in a mol.wt. range of >=300,000 satisfy the relations of 1<=(L/T)×100<=15 and 3<=(H/T)×100<=30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic image developing toner for developing an electrostatic latent image and an image forming method using the toner.

[0002]

2. Description of the Related Art Electrophotography is disclosed in U.S. Pat.
Numerous methods are known, as described in US Pat. In general, using a photoconductor made of a photoconductive substance, an electric latent image is formed on the photoconductor by various means,
Next, the latent image is developed using a toner to form a visible image,
If necessary, a toner image is transferred to a transfer material (recording material) such as paper, and then the toner image is fixed on the transfer material by heat and / or pressure to obtain a copy or print. Conventionally, various methods have been proposed for fixing a toner image. For example, a transfer roller such as paper having an unfixed toner image on its surface is nipped and conveyed by a heating roller maintained at a predetermined temperature and a pressure roller having an elastic layer and pressing against the heating roller. The fixing method is widely used. However, in this method, since the surface of the heat roller and the toner image come into contact with each other under pressure in a molten state, a part of the toner image adheres and transfers to the surface of the fixing roller, and the adhered toner is transferred to the next transfer material. A phenomenon of re-transfer, a so-called offset phenomenon, is likely to occur.

Further, as a method for preventing the offset phenomenon, for example, Japanese Patent Application Laid-Open Nos. 1-214772, 2-204752, 2-204723, 3-77962, and 3 −2848
No. 67 and JP-A-4-81863 disclose a toner containing a binder resin and wax and having excellent fixing properties and offset resistance. For example, JP-A-5-602
In Gazette No. 9, in the molecular weight distribution by GPC, the region having a molecular weight of 5,000 or less is less than 15%, and the molecular weight is 50%.
5% or more in the region of 100,000 or more, and the molecular weight of 5,000 to
A toner having a main peak in a 100,000 region and a weight average molecular weight of 5,000,000 or more has been proposed. In this case, low-temperature fixability, anti-blocking property, prevention of filming and fusing to a photoreceptor, and development characteristics are excellent.

The above-described offset prevention method is a pulverization method in the toner production method class, that is, a colorant comprising a dye or a pigment is melt-kneaded in a thermoplastic resin, uniformly dispersed, and then pulverized by a pulverizer. And a method in which the finely pulverized material is classified by a classifier and has a desired toner particle size. However, the suspension polymerization method, i.e., a monomer composition obtained by uniformly dissolving or dispersing a polymerizable monomer, a colorant and a polymerization initiator, and further, if necessary, a crosslinking agent, a charge control agent, and other additives. Is prepared by dispersing the monomer composition in a continuous phase containing a dispersion stabilizer, for example, an aqueous phase using a suitable stirrer, and performing a polymerization reaction to obtain a desired toner particle size. In this case, the offset resistance can be more effectively improved. For example, JP-A-5-8
No. 8409, the low softening point substance is uniformly dissolved or dispersed in the monomer composition, and the polarity in the aqueous phase of the low softening point substance is set smaller than that of the main monomer. A toner having a so-called core / shell structure in which a low softening point substance is coated with an outer resin by adding a small amount of a resin or monomer having a large polarity has been proposed. In this case, it is possible to obtain a toner having excellent durability and development characteristics, which does not impair filming on the photoreceptor and does not easily contaminate the surface of the toner carrier (development sleeve) of the carrier without impairing the low-temperature fixability.

[0005] In particular, when performing image formation or the like using a full-color toner, a single-color toner is superposed in multiple layers and then mixed by heating and melting, so that a so-called secondary color is formed. , An offset phenomenon may occur.

Conventionally, in order to prevent the toner from adhering to the surface of the fixing roller, for example, the surface of the roller is formed of a material having excellent releasability (for example, silicone rubber or fluorine resin) with respect to the toner, and the surface of the roller is further offset. In order to prevent this and to prevent the roller surface from being fatigued, the roller surface is coated with a thin film of a liquid having good releasability such as silicone oil. However, although this method is extremely effective in preventing toner offset, it has a problem that a fixing device becomes complicated because an apparatus is required to supply an offset preventing liquid. Therefore, it is not preferable that the offset is prevented by supplying the offset preventing liquid, and the development of an offset-resistant toner having a wide fixing temperature range is desired.

Therefore, in order to increase the releasability of the toner, a method of adding a wax having a low molecular weight such as polyethylene or polypropylene, which sufficiently melts when heated, has been used. The use of wax is effective in preventing offset, but increases the cohesiveness of the toner, makes the charging characteristics unstable, and tends to cause a decrease in durability. Therefore, various attempts have been made to improve the binder resin as another method.

For example, there is known a method of increasing the glass transition temperature (Tg) and the molecular weight of the binder resin in the toner to improve the melt viscoelasticity of the toner in order to prevent offset. However, when the offset phenomenon is improved by such a method, there arises a problem that the fixability becomes insufficient and the fixability at a low temperature (that is, low-temperature fixability) required for high-speed copying machines and energy saving is inferior. .

In view of the above, in order to improve the fixability of the toner, it is necessary to lower the viscosity of the toner at the time of melting and increase the area of adhesion to the fixing substrate. For this purpose, it is required to lower the Tg and molecular weight of the binder resin used.

Since low-temperature fixability and anti-offset properties have contradictory aspects, it is very difficult to develop a toner that satisfies these functions simultaneously.

In order to solve these problems, for example, Japanese Patent Publication No. 51-23354 proposes a toner comprising a vinyl copolymer which is appropriately crosslinked by adding a crosslinking agent and a molecular weight modifier. Japanese Patent Publication No. 55-6805 discloses that the molecular weight distribution is broadened so that the ratio of the weight average molecular weight to the number average molecular weight using α, β-unsaturated ethylenic monomer as a constitutional unit is 3.5 to 40. The proposed toner has been proposed. Further, a toner using a blend resin in which Tg, molecular weight, and gel content are specified in a vinyl polymer has been proposed.

Certainly, the toner according to these proposals has a lower fixing temperature (lowest temperature at which fixing is possible) and an offset temperature (temperature at which offset starts to occur), compared to a toner made of a single resin having a narrow molecular weight distribution. Although the temperature range in which fixing can be performed is widened, it is difficult to sufficiently lower the fixing temperature when sufficient offset prevention performance is provided. Conversely, there is a problem that if low-temperature fixability is emphasized, the offset prevention performance becomes insufficient.

For example, Japanese Patent Application Laid-Open No. 56-158340 proposes a toner comprising a low molecular weight polymer and a high molecular weight polymer. Since it is actually difficult for the binder resin to contain a cross-linking component, in order to improve the offset resistance with high performance, increase the molecular weight of the high molecular weight polymer or reduce the ratio of the high molecular weight polymer. Need to increase. This direction is a direction in which the pulverizability of the resin composition is significantly reduced, and it is difficult to obtain a practically satisfactory one.

Further, regarding a toner blended with a low molecular weight polymer and a crosslinked polymer, Japanese Patent Application Laid-Open No. 58-86558 discloses a toner comprising a low molecular weight polymer and an insoluble infusible high molecular weight polymer as main resin components. Has been proposed. According to the method, it is considered that the fixability of the toner and the pulverizability of the resin composition are improved. However, the weight average molecular weight / number average molecular weight (Mw / Mn) of the low molecular weight polymer is 3.
When it is as small as 5 or less, and when the amount of the insoluble and infusible high molecular weight polymer is as large as 40 to 90% by weight, it is difficult to satisfy both the offset resistance of the toner and the pulverizability of the resin composition with high performance. In practice, it is extremely difficult to produce a toner that sufficiently satisfies the fixing property and the anti-offset property unless the fixing machine has a device for supplying an anti-offset liquid.
Further, when the amount of the insoluble and infusible high molecular weight polymer increases, the melt viscosity becomes extremely high by hot kneading at the time of toner production, so that it is necessary to heat knead at a much higher temperature than usual, and as a result,
There is a problem that the toner characteristics are deteriorated due to the thermal decomposition of the additive.

JP-A-56-16144 discloses that GP
In the molecular weight distribution by C, the molecular weight is 10 ³ to 8 × 10
^There has been proposed a toner containing at least one binder resin component having at least one maximum value in each of the regions having a molecular weight of ⁴ and a molecular weight of 10 ^{5 to} 2 × 10 ⁶ . In this case, the pulverizability of the binder resin component, the anti-offset property of the toner, the fixing property, the prevention of filming and fusing to the photoreceptor, and the development characteristics are excellent. Further, there is a demand for an improvement in offset resistance and fixability of the toner. In particular, it is difficult for the resin to meet today's strict requirements while further improving the fixing property and maintaining or improving various other performances.

As described above, it is extremely difficult to realize high performance related to fixing of toner (low-temperature fixing property and offset prevention property).

However, in recent copiers and printers, demands for miniaturization, weight reduction, and high reliability are increasing, and requirements for toner performance are becoming strict. For example, there has been a demand for a toner having excellent durability that does not impair the low-temperature fixing property and that is less likely to contaminate the surface of a toner carrier such as a carrier or a sleeve without impairing the photoreceptor.

JP-A-59-21845 and JP-A-59-21845.
JP-A-218460, JP-A-59-219755, JP-A-60-28665, JP-A-60-31147,
JP-A-60-45259, JP-A-60-45260 and JP-A-3-197971 disclose toner TH.
A toner having excellent fixability is proposed by specifying the insoluble content in a solvent such as F or toluene. However, further improvement is required at present from the viewpoint of achieving both low-temperature fixability and durability.

JP-A-60-31147 and JP-A-3-197971 further specify the molecular weight of the soluble component. However, further improvements are currently required from the viewpoint of durability.

Japanese Patent Application Laid-Open No. Hei 3-251853 discloses a suspension polymerization method wherein the molecular weight distribution has a plurality of peaks, and when the position of the minimum molecular weight peak is 50,000 or less, the position of the maximum molecular weight peak is 200,000 or more. Has been proposed. However, further improvement is currently required from the viewpoint of low-temperature fixability.

Japanese Patent Application Laid-Open No. 3-39971 discloses a GPC
, The peak M in the molecular weight region of 500 to 2,000
p1, a peak Mp2 in a molecular weight range of 10,000 to 100,000, and a weight average molecular weight (Mw) of 1
000 to 80,000 and a number average molecular weight (M
A color toner in which n) is 1,500 to 8,000 and the ratio of Mw / Mn is 3 or more has been proposed. In this case, a color toner which is excellent in offset resistance and has a high color saturation and a clear color image can be obtained, but without impairing the low-temperature fixability, filming on the photoreceptor, There is a need to develop a toner that is less likely to contaminate the surface of a toner carrier such as a carrier or a sleeve.

On the other hand, in the conventional electrophotographic process, after the transfer step, toner particles remaining on the photoreceptor without being transferred onto the transfer material are removed from the photoreceptor by a cleaning step using a cleaning means. Is common. As the cleaning means, blade cleaning, fur brush cleaning or roller cleaning is used.

From the viewpoint of the apparatus, the provision of such a cleaning device inevitably increases the size of the entire image forming apparatus, which has been a bottleneck when the size of the apparatus is reduced.

Further, from the viewpoint of ecology, there has been a demand for a cleaning-less system and a toner reuse system which do not generate waste toner in terms of effective use of toner.

Conventionally, a technique called simultaneous development cleaning or cleanerless is disclosed in, for example, Japanese Patent Publication No. 5-69427.
In this method, one image is made per rotation of the photoconductor so that the influence of the residual toner on the transfer does not appear in the same image. JP-A-64-205
No. 87, JP-A-2-259784, JP-A-4
In JP-A-50-886 and JP-A-5-165378, even if the same surface of the photoreceptor is used a plurality of times for one image, the residual toner is dispersed on the photoreceptor by a dispersing member and non-patterned. Discloses a configuration that is difficult to appear on an image, but has a problem in deterioration of image quality. Japanese Patent Laid-Open No. 5-2287 discloses a configuration in which the relationship between the amounts of toner charged around the photoreceptor is defined so that a positive memory and a negative memory do not appear on the image due to the influence of the residual toner on the image. Does not disclose what configuration controls the toner charge amount.

Furthermore, JP-A-59-133573, JP-A-62-203182, and JP-A-63-1331, which disclose techniques related to cleanerless.
No. 79, JP-A-2-302772, JP-A-4
In JP-A-155361, JP-A-5-2289, JP-A-5-53482, and JP-A-5-61383, in regard to image exposure, high-intensity light is irradiated or the exposure wavelength is reduced. A method such as using a toner that transmits light is proposed. However, simply increasing the exposure intensity causes bleeding in dot formation of the latent image itself, resulting in insufficient isolated dot reproducibility and poor resolution in terms of image quality, particularly in a graphic image without gradation. . Regarding means using a toner that transmits light of the exposure wavelength, the effect of light transmission is large as much as possible on the fixed toner without grain boundaries, but as a mechanism to block exposure, rather than coloring the toner itself,
Scattering on the surface of the toner particles is main and the effect is small. Further, the range of selection of the colorant of the toner is narrowed, and in addition, when aiming for colorization, at least three types of exposure means having different wavelengths are required. Go backwards.

A contact charging method of charging by contacting a photoreceptor and a contact transfer method of transferring by contacting a photoreceptor via a transfer material are generally desirable from the viewpoint of ecology with little generation of ozone. Configuration. The transfer member is
It also has the characteristic that it can also be used as a transfer member for the transfer material, making it easier to reduce the size of the apparatus. However, if the cleaning in the developing section is insufficient, the charging member and the transfer member are easily stained, and image stains due to poor charging of the photoreceptor, back stains on the transfer material, or a dropout during transfer where the center of the line portion is not transferred. There is a problem that this tends to further accelerate image deterioration.

Further, in the simultaneous development and cleaning which essentially has no cleaning device, it is essential to rub the surface of the latent image holding member with the toner and the toner carrying member. This causes deterioration of the body surface, the surface of the image carrier, or abrasion, and the deterioration of the durability characteristic remains as a problem. Therefore, the conventional technology has not sufficiently solved the problem, and a technique for improving the durability characteristic has been desired.

In particular, there has been a need to improve toner contamination on the latent image holding member surface, that is, the photosensitive member surface. Conventionally, to solve these problems, it has been proposed to impart releasability or lubricity to the toner or the photoconductor. For example, JP-B-57-13868, JP-A-54-58245, JP-A-59-197048, and JP-A-2-30.
No. 73, JP-A-3-63660 and U.S. Pat. No. 4,517,272 disclose a method of incorporating a silicone compound into a toner.
Japanese Patent Application No. 99345/1999 discloses a method of incorporating a lubricating substance represented by a fluorine-containing compound into the surface layer of a photoreceptor.

However, there is no example in which these methods are applied to a so-called cleaning-less, simultaneous-development cleaning system having essentially no cleaning device.

In recent years, various organic photoconductive materials have been developed as a photoconductive material for an electrophotographic photoreceptor, and a function-separated type in which a charge generation layer and a charge transport layer are laminated has been put to practical use.
It is mounted on an image forming apparatus such as a copying machine, a printer, and a facsimile. As a charging unit in such an electrophotographic method, a unit using corona discharge has been used. However, since a large amount of ozone is generated, it is necessary to provide a filter. There was a problem of up.

As a technique for solving such a problem, a charging member such as a roller or a blade is brought into contact with the surface of a photoreceptor to form a narrow space in the vicinity of the contacting portion, which is interpreted according to the so-called Paschen's law. A charging method has been developed in which the generation of ozone is suppressed as much as possible by forming a discharge as possible. Among these, a roller charging method using a charging roller as a charging member is particularly preferably used from the viewpoint of charging stability.

More specifically, since charging is performed by discharging from the charging member to the member to be charged, the charging is started by applying a voltage higher than a certain threshold. For example, when the charging roller is brought into contact with an OPC photosensitive member having a photosensitive layer thickness of 25 μm, the surface potential of the photosensitive member starts to increase when a voltage of about 640 V or more is applied, and thereafter, the applied voltage is increased. The photosensitive member surface potential increases linearly at an inclination of 1.
Hereinafter, this threshold voltage is defined as a charging start voltage Vth. That is, in order to obtain the photoconductor surface potential Vd, the charging roller needs a DC voltage higher than Vd + Vth. However, since the resistance value of the contact charging member fluctuates due to environmental fluctuations or the like, it has been difficult to set the potential of the photoconductor to a desired value.

Therefore, in order to further uniform the charging, Japanese Patent Application Laid-Open No. 63-149669 discloses an AC component having a peak-to-peak voltage of 2 × Vth or more superimposed on a DC voltage corresponding to a desired Vd. To apply the applied voltage to the contact charging member
A charging system is disclosed. This is for the purpose of the leveling effect of the potential by AC, and the potential of the charged body converges to Vd, which is the center of the peak of the AC voltage, and is hardly affected by disturbance such as environmental fluctuation.

However, even in such a contact charging device, the essential charging mechanism uses a discharging phenomenon from the charging member to the photosensitive member, so that the voltage required for charging as described above is used. Requires a value equal to or higher than the photoconductor surface potential. When AC charging is performed for uniform charging, A
Vibration and noise of the charging member and the photoconductor due to the electric field of the C voltage occur, and the deterioration of the photoconductor surface due to the discharge becomes remarkable.
It was a new problem.

JP-A-61-57958 discloses an image forming method in which a photosensitive member having a conductive protective film is charged using conductive fine particles. To this, a photoreceptor using with semiconductive protective film having a resistivity of 10 ⁷ to 10 ¹³ [Omega] cm as a photosensitive member, the photosensitive member 10 ¹⁰ [Omega] cm
By charging using conductive fine particles having the following resistance, the photoconductor can be uniformly charged by discharge without unevenness without injecting charge into the photosensitive layer, and good image reproduction can be performed. It is described as possible. According to this method, vibration and noise, which are problems in AC charging, can be prevented. However, since charging is performed by discharging, deterioration of the photoconductor surface due to discharging still occurs, and a high-voltage power supply is also required. . For this reason, charging by direct injection of charges into the photoconductor has been desired.

A method of applying a voltage to a contact charging member such as a charging roller, a charging brush or a charging magnetic brush and injecting a charge into a trap level on the surface of the photoreceptor to perform contact injection charging is disclosed in Japan Hardcopy, 1992. P2
87, "Contact Charging Characteristics Using Conductive Rollers". This method is used for photoconductors that are insulated in the dark.
Injection charging is performed using a low-resistance charging member to which a voltage has been applied. The charging member has a sufficiently low resistance value and a material (conductive filler or the like) that imparts conductivity to the charging member is sufficiently exposed on the surface. Had to be a condition.

For this reason, the above-mentioned documents also state that the charging member is preferably an aluminum foil or an ion-conductive charging member having a sufficiently reduced resistance under a high humidity environment. According to the study by the present applicants, the resistance value of the charging member capable of sufficiently injecting electric charge into the photoreceptor is 1 × 10 ³ Ωcm or less. Above this value, a difference occurs between the applied voltage and the charging potential. It is known that a problem arises in the convergence of the charging potential at first.

However, when such a charging member having a low resistance value is actually used, an excessive leakage current flows from the contact charging member into a flaw, a pinhole, or the like generated on the surface of the photoreceptor, thereby causing poor charging around the photosensitive member. As a result, the pinholes are enlarged, and the charging member is deenergized.

In order to prevent this, the resistance of the charging member needs to be about 1 × 10 ⁴ Ωcm or more. And the contradiction that charging is not performed occurs.

Therefore, the above-mentioned problems with the contact type charging device or the image forming method using the charging device are solved, that is, the charge injection which does not occur unless a low-resistance contact charging member is used. It has been desired to be able to simultaneously achieve both good charging properties and contradictory characteristics such as pinhole leak on a member to be charged, which could not be prevented by a low-resistance contact charging member.

Further, in an image forming method using contact charging, an image defect due to poor charging due to contamination (spent) of the charging member tends to occur, causing a problem in durability, and charging due to charge injection into the member to be charged. In this case, it was urgently necessary to prevent the influence of defective charging due to contamination of the charging member in order to enable printing of a large number of sheets.

Using contact charging and without cleaning,
Examples of application to a system referred to as simultaneous development cleaning are disclosed in Japanese Patent Application Laid-Open Nos.
No. 230652 is known. These publications disclose an image forming method in which the transfer residual toner on the photoreceptor is simultaneously cleaned in the back exposure simultaneous development method.

However, these proposals are based on the charging potential,
This method is applied to an image forming process in which a developing application bias is set to a low electric field. Image defects such as the following.

Further, there has been proposed a method for preventing the adverse effect of the transfer residual toner from adhering to the charging member by transferring the toner adhering to the charging member to the photosensitive member during non-image formation. No mention is made of the improvement of the retrievability in the developing step and the effect of the toner recovery in the developing step on the development.

Furthermore, if the cleaning effect of the transfer residual toner at the time of development is insufficient, the toner is developed on the surface of the photoreceptor where the transfer residual toner is present. In addition, if the amount of toner remaining after transfer is too large, a positive memory is generated on the image because the toner cannot be completely collected in the developed portion, but these problems have not been essentially solved.

The problem of light shielding by the transfer residual toner is particularly problematic when the surface of the photosensitive member is repeatedly used for one transfer material, that is, the length of one circumference of the photosensitive member is longer than the length of the transfer material in the traveling direction. It is a short case. Since the charge exposure and development must be performed in a state where the transfer residual toner is present on the photoconductor, the potential on the surface of the photoconductor where the transfer residual toner is present cannot be sufficiently reduced, and the development contrast becomes insufficient. Appears on the image as a negative ghost with a lower density than the surroundings. The photoreceptor that has passed the electrostatic transfer is charged to a polarity generally opposite to the toner charging polarity. Toner
Leakage from the charging member during image formation interrupts the exposure, disturbs the latent image and fails to obtain the desired potential, and generates a negative memory on the image. There is a need for an essential solution to these problems.

[0048]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a photoreceptor without filming, without impairing the low-temperature fixability.
An object of the present invention is to provide a toner for developing an electrostatic image, which is less likely to contaminate the surface of a toner carrier such as a carrier and a sleeve, and has excellent offset resistance and durability.

It is an object of the present invention to provide a toner for developing an electrostatic charge image having excellent charge stability irrespective of environmental differences such as temperature difference and humidity difference.

An object of the present invention is to provide a toner for developing an electrostatic charge image capable of obtaining a clear color OHP image.

It is an object of the present invention to provide a toner for developing an electrostatic charge image capable of obtaining a color image requiring no fixing oil.

The object of the present invention is to provide a multi-sheet
An object of the present invention is to provide an image forming method having a charging member capable of maintaining good charging characteristics.

An object of the present invention is to provide an image having an electrophotographic photosensitive member and a member for injecting and charging the photosensitive member, and having a charging step in which the photosensitive member is charged by applying a voltage from the member for injecting and charging. An object of the present invention is to provide an image forming method capable of maintaining good charging characteristics for a long period of time.

It is an object of the present invention to simultaneously achieve both good charging properties due to charge injection and contradictory characteristics such as leakage due to pinholes on a photoreceptor which could not be prevented by a low-resistance contact charging member. An object of the present invention is to provide an image forming method having a charging step which is enabled.

An object of the present invention is to provide an image forming method capable of forming a high-speed image at a high process speed.

[0056]

The above object is achieved by the following constitution of the present invention.

The present invention relates to a toner for developing an electrostatic image containing at least a binder resin, a colorant and a release agent, in the molecular weight distribution of the THF-soluble component of the toner by gel permeation chromatography (GPC). The THF-soluble component has a molecular weight of 1,000 to 2,000.
Has at least one peak in a region less than 00,
It has at least one peak in a molecular weight range of 2,000 to 3,000,000, and has a peak of 90,000 to 2,000.
Has a weight average molecular weight (Mw) of 00,000,
The molecular weight integrated value (T) of the region having a molecular weight of 800 or more, the molecular weight integrated value (L) of the region having a molecular weight of 2,000 to 5,000, and the molecular weight integrated value (H) of the region having a molecular weight of 3,000,000 or more are as follows. Relation: The present invention relates to a toner for developing an electrostatic image, wherein 1 ≦ (L / T) × 100 ≦ 153 and 3 ≦ (H / T) × 100 ≦ 30.

Further, the present invention provides a step of charging a surface of a latent image holding member for holding an electrostatic latent image; a step of forming an electrostatic latent image on the charged surface of the latent image holding member; Developing the electrostatic latent image with toner to form a toner image;
Transferring the developed toner image to a recording material with or without an intermediate transfer member; and fixing the transferred toner image to the recording material. And at least a binder resin, a colorant, and a release agent. In the molecular weight distribution of the THF-soluble component of the toner by gel permeation chromatography (GPC), the THF-soluble component has a molecular weight of 1,
It has at least one peak in the region of 2,000 to less than 2,000, and has a molecular weight of 2,000 to 300,000.
Has at least one peak in the region of
Weight average molecular weight (Mw) of 00 to 2,000,000
And a molecular weight integrated value (T) in a region having a molecular weight of 800 or more, a molecular weight integrated value (L) in a region having a molecular weight of 2,000 to 5,000, and a molecular weight integrated value in a region having a molecular weight of 300,000 or more. (H) satisfies the following relationship: 1 ≦ (L / T) × 100 ≦ 153 3 ≦ (H / T) × 100 ≦ 30.

[0059]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In general, in order to impart fixability to a toner, at a temperature higher than room temperature, that is, at a fixing temperature, the viscosity sharply decreases, flows onto a transfer material such as paper, and partially becomes inside the transfer material. A resin that penetrates and rapidly recovers the viscosity at about room temperature and is fixed to the transfer material may be used, and a dispersion of the pigment in the resin may be used as a main component of the toner. Such a resin is called a binder resin. In order to impart offset resistance to the toner, the viscosity starts to decrease sharply at a temperature from room temperature to the fixing temperature, and at the fixing temperature, the fluidity is better than that of the binder resin, and the viscosity of the binder and the fixing roller is higher. A low softening point substance which can easily be present therebetween may be used as a sub-component of the toner. Such a low softening point substance is called a release agent.

The present inventors have conducted intensive studies on a toner containing a binder resin and a release agent. As a result, the binder resin has a molecular weight of 2,000 in the molecular weight distribution by GPC.
It has been found that it is optimal to have a main peak in the range of 0 to 300,000. The binder resin has a molecular weight of 2,
If it has a main peak in a region of less than 000, it may contaminate the surface of the toner carrier such as a carrier and a sleeve,
Filming of the photoconductor may occur. When the binder resin has a main peak in a region exceeding a molecular weight of 300,000, the low-temperature fixability deteriorates.

In addition, as a result of intensive studies, the present inventors have found that a wax as a release agent has a main peak in a molecular weight distribution of 1,000 to less than 2,000 in a molecular weight distribution by GPC. It was found that. When the wax has a main peak in a region having a molecular weight of less than 1,000, the wax leaks out of the toner at room temperature, so that the toner has poor durability and shelf stability. When the wax has a main peak in a region having a molecular weight of 2,000 or more, sufficient fluidity does not occur even at a fixing temperature, and it is difficult for a sufficient amount of molten wax to exist between the binder and the fixing roller. Becomes

[0062] These binders and waxes are GPC
In the measurement, the peaks are located at different positions from each other, but when the components constituting the valley between these peaks are present continuously and in a large amount in the toner by GPC measurement, It becomes difficult to separate the functions of the fixing property and the releasability, that is, the fixing property function of the binder resin and the releasability function of the wax reduce the effect of each other, resulting in a toner having poor fixing property and offset resistance.
In addition, the photosensitive member, the contact charging member that contacts the photosensitive member, the contact transfer member, and the toner carrier are easily contaminated.

On the other hand, when the component constituting the valley between these top peaks does not exist in the GPC measurement, the fixing function by the binder resin and the releasing function by the wax do not cancel each other. . However, in this case, the wax and the binder resin are hardly compatible with each other, and the wax component and the binder resin component are separated from each other.
The resulting toner has poor shelf stability.

The present inventors have conducted intensive studies and found that the molecular weight is 80
Molecular weight 2, relative to the molecular weight integrated value (T) in the region of 0 or more
A toner in which the ratio (L / T) × 100 of the molecular weight integrated value (L) × 100 in the region of 000 to 5,000 is 1 to 15, preferably 1 to 7 maintains the low-temperature fixability well, It has been found that the toner hardly contaminates the surface of a toner carrier such as a carrier or a sleeve.

That is, the molecular weight is 2,000 to 300,000.
Is a binder resin component having a molecular weight of 1,000 to 2,
When the component in the region of less than 000 is considered as a release agent component, when each has a peak in the molecular weight region, the molecular weight distribution of each peak exhibits a sharp distribution, and the molecular weight of the binder resin component is 2, 000-5,000
Can be an essential component for fixing the toner to the paper even with low energy, especially when the fixing temperature is lowered when high-speed copying or continuous paper feeding is performed. When the binder resin component is continuously connected to the distribution of the adjacent release agent component, as described above, when the components constituting the valley between the respective peak tops are too large, each active component is Since there are cases where they are mutually canceled, the abundance of the components constituting the valley between the peak tops must be a specific ratio.

If the value of (L / T) × 100 exceeds 15, it becomes difficult to separate the function of the binder component from the wax component that generates the releasing effect, and the function between the fixing function and the releasing function becomes difficult. The effects are mutually reduced, and it is difficult to achieve a high degree of compatibility between the fixing property and the offset resistance. (L / T)
When the value of x100 is less than 1, the chargeability of the toner becomes unstable because the binder component and the wax component are easily separated.

The high molecular weight component having a molecular weight of 300,000 or more makes the toner robust and gives the toner durability and storage stability. However, if it is present in a large amount, the fixing temperature rises, which is not preferable. The present inventors have conducted intensive studies and found that a molecular weight of 80 was obtained.
Molecular weight 30 with respect to the molecular weight integrated value (T) in the region of 0 or more
The ratio (H) of the molecular weight integrated value (H) in the region of 0000 or more
It has been found that a toner having excellent durability can be obtained when (/ T) × 100 is 3 to 30, preferably 5 to 25, without impairing the fixing temperature property.

Such a component having a molecular weight of 300,000 or more, which is generally regarded as a high molecular weight component, not only adversely affects the fixing property when the amount thereof is large, but also reduces the instability of toner production. GPC
In the chromatogram chart, it is said that the high molecular weight in the vicinity of the above range is small in its fraction and the peak is preferably a horizontally long distribution. However, it is difficult to effectively extract both properties because the toner exhibits opposite properties in terms of storage stability and surface strength of toner particles themselves.

However, in the present invention, as described above, it has been found that the low molecular weight region of the binder resin component, which is largely due to the fixing property of the toner in the molecular weight distribution, enhances the fixing property. It is very useful that a high molecular weight component for maintaining storage stability and surface strength as described above exists in the above-mentioned specific amount.

When the value of (H / T) × 100 exceeds 30, the low-temperature fixability of the toner decreases, and
Since the change in the amount of charge of the toner is large, an offset is likely to occur in the case of an image output by forming the toner in multiple layers. When the value of (H / T) × 100 is less than 3, the toner blocking characteristics after long-term storage are deteriorated, and the charging member is easily contaminated. Furthermore, in the present invention, the resin component in the region having a molecular weight of 100,000 or more is a component that acts on the anti-blocking property and storage stability of the toner. The ratio (M / T) × 100 of the molecular weight integrated value (M) in the region having a molecular weight of 100,000 or more preferably satisfies the above-mentioned characteristics, and is 10 to 50, more preferably 15 to 40. This is good in that good charging characteristics can be obtained by maintaining the fluidity stably.

If the value of (M / T) × 100 exceeds 50, the dispersibility of the colorant and the charge control agent during the production of the toner decreases, and it becomes difficult to uniformly disperse the toner in the toner particles. In addition, it becomes difficult to obtain a desired charge amount (M / T)
If the value of x100 is less than 10, offset tends to occur on the high temperature side.

Further, in the present invention, a molecular weight of 800
It is particularly preferable that Mw / Mn in the region of 3,000 to 3,000 is 3.0 or less.

In the present invention, in the molecular weight distribution, the peak top height (Hb) and the molecular weight of 1,000 to 2,000 in the molecular weight range of 2,000 to 300,000 are used.
Peak top height (Ha) in the region less than 000
(Hb / Ha) is preferably 0.70 to 1.3.
0, more preferably 0.75 to 1.25.

Regarding the relationship of the height ratio (Hb / Ha), the fact that a large number of release components, which are low softening point substances, is present means that the toner maintains more preferable release properties with respect to the heat fixing roller. Is possible. In this case, the molecular weight distribution of the binder resin component described above reflects a state where the molecular weight distribution is sharply cut on the low molecular weight side, and the release agent component does not exhibit an inhibitory effect on the molecular weight of the binder resin component. It is possible to exhibit high releasability of the toner with respect to the heat fixing roller while maintaining the fixing property.

When Hb / Ha is less than 0.70, the wax easily flows out of the toner under normal temperature conditions, resulting in a toner having poor durability and storage stability. Also, Hb / Ha
Exceeds 1.30, the wax content is not sufficient and the toner has poor offset resistance. In particular, an unfixed image composed of multiple layers at the time of full-color image formation is pressed by the heat fixing roller unit. In such a case, an offset easily occurs.

Further, in the molecular weight distribution, the height of the minimum value of the molecular weight existing between the peak top in the molecular weight range of 2,000 to 300,000 and the peak top in the molecular weight range of 1,000 to less than 2,000 ( H
c) and the ratio (Hc / Ha) of the peak top height (Ha) in the region having a molecular weight of 1,000 to less than 2,000 is preferably 0.01 to 1.15, more preferably 0.1 to 1.15.
01 to 0.10, more preferably 0.01 to 0.0
More preferably, it is 0.02 to 0.07.

If Hc / Ha is less than 0.01, the wax and the binder are hardly compatible with each other, and the wax component and the binder component are immediately separated, resulting in a toner having poor durability and storage stability. When Hc / Ha exceeds 0.15, it is difficult to separate the functions of the binder and the wax, that is, the effects between the binder function and the wax function are reduced, resulting in a toner having poor fixability and offset resistance.

Further, in the present invention, the toner TH
In the molecular weight distribution of F-soluble components by GPC, the weight average molecular weight (Mw) is 90,000 to 2,000,000,
Preferably, it is good to be 100,000-1500,000.

The weight average molecular weight (Mw) of the toner is 90,
If it is less than 000, the blocking resistance of the toner may be reduced, and filming on the photoreceptor surface may occur. When the weight average molecular weight of the toner is 2,000
When it exceeds 000, the offset on the high temperature side is liable to occur, the dispersibility of the colorant tends to decrease, and in addition to the decrease in image quality, the uniform toner particles Is difficult to obtain.

Further, in the present invention, the toner TH
In the molecular weight distribution of the F-soluble component by GPC, the number average molecular weight (Mn) is preferably from 8,200 to 700,00.
0, more preferably 8,300 to 500,000.

The number average molecular weight (Mn) of the toner is 8,20
If it is less than 0, the storage stability of the toner is lacking, and the fluidity tends to deteriorate, and the number average molecular weight (Mn) of the toner
Exceeds 700,000, the production stability of the toner becomes unstable, making it difficult to obtain uniform toner particles and affecting the triboelectric charging property of the toner.

Further, Mw / Mn indicating the width of the molecular weight distribution.
Is preferably 4 to 15, more preferably 5 to 13.

When Mw / Mn is less than 4, the blocking resistance of the toner tends to decrease, and when Mw / Mn exceeds 15, the melting characteristics of the binder component become slow. When used as a color toner, the sharp melt property required for sufficient color development is impaired, faithful color reproducibility is hardly obtained, and color mixing with other color toners is also reduced.

In the present invention, the molecular weight distribution of the chromatogram of the THF-soluble component of the toner by GPC (gel permeation chromatography) is measured under the following conditions.

The toner was previously extracted with a toluene solvent using a Soxhlet extractor for 20 hours, and toluene was distilled off from the obtained extract using a rotary evaporator. The extract was then dissolved in THF (tetrahydrofuran), and sampled. Processing filter (pore size 0.3-0.5 μm,
For example, preferably used are Mishoridisc h-25-2 manufactured by Tosoh Corporation and Exiclodisc 25CR manufactured by Germanic Science Japan. G)
Use as a PC sample. The sample concentration was 0.5 to 5 for the resin component.
Prepare to be mg / ml.

In the GPC measuring apparatus, the column was stabilized in a heat chamber at 40 ° C., and THF was passed through the column at this temperature as a solvent at a flow rate of 1 ml / min.
About 100 μl of a THF sample solution is injected and measured. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the count number (retention time). As a standard polystyrene sample for preparing a calibration curve, for example, one having a molecular weight of about 10 ² to 10 ⁷ manufactured by Tosoh Corporation or Showa Denko KK is used.
It is appropriate to use about 0 standard polystyrene samples. An RI (refractive index) detector is used as the detector. As the column, a combination of a plurality of commercially available polystyrene gel columns may be used. For example, a Showa Denko
x GPC KF-801,802,803,804,
805, 806, 807, 808P, TSKgel G1000H (Hx1), G2
000H (Hx1), G3000H (Hx1), G40
00H (Hx1), G5000H (Hx1), G600
0H (Hx1), G7000H (Hx1), TSKgu
and ardcolumn combinations.

From the molecular weight distribution by GPC obtained by the above method, the molecular weight integrated value (T) in the region of molecular weight 800 or more, the molecular weight integrated value (L) in the region of molecular weight 2,000 to 5,000, the molecular weight 100, The molecular weight integrated value (M) in the region of 000 or more and the molecular weight integrated value (H) in the region of 300,000 or more are calculated.

Further, from the molecular weight distribution obtained by the GPC obtained by the above method, the peak top height (Hb) and the molecular weight 1,2 in the molecular weight region of 2,000 to 300,000 were obtained.
The ratio (Hb / Ha) to the peak top height (Ha) in the region of 2,000 to less than 2,000 and the molecular weight of 2,000
The height (Hc) of the minimum value of the molecular weight existing between the peak top in the region of 00 to 300,000 and the peak top in the region of 1,000 to less than 2,000 and the region of 1,000 to 2,000 in molecular weight. The ratio (Hc / Ha) to the height (Ha) of the peak top at is calculated by the following method.

The obtained molecular weight distribution has a molecular weight of 1,000 to 1,000.
Region less than 2,000 and molecular weight 2,000-3,000
A perpendicular is drawn from each local maximum in the region of 0000 toward the baseline. The length of the perpendicular drawn from the highest peak (peak top) in the region of molecular weight 2,000 to 300,000 is defined as the height of the peak top (Hb) in the region of molecular weight 2,000 or more. In addition, molecular weight 1,
The length of the perpendicular drawn from the highest peak (peak top) in the region of 000 to less than 2,000 is defined as the height of the peak top (Ha) in the region of 1,000 to less than 2,000.

The obtained molecular weight distribution has a molecular weight of 2,000 to 2,000.
A perpendicular line is drawn from the minimum molecular weight between the peak top in the region of 300,000 and the peak top in the region having a molecular weight of 1,000 to less than 2,000 toward the baseline, and the lowest point (lowest point) in the above region From the peak top in the region of molecular weight of 2,000 to 300,000 and the molecular weight of 1,000 to 2,000.
The height (Hc) of the minimum molecular weight existing between the peak tops in a region less than 0 is defined.

By using these Ha, Hb and Hc, Hb /
Ha and Hc / Ha were calculated.

Further, in the present invention, the resin component of the toner contains a toluene-insoluble component (that is, a gel component) to improve the offset resistance at the time of fixing and to deform the toner at the time of fixing and melting. It is preferable in that it is easy to cause.

In the present invention, the resin component of the toner preferably contains a toluene-insoluble component in an amount of preferably 2 to 30% by weight, more preferably 3 to 25% by weight, based on the weight of the resin component. .

When the content of the toluene-insoluble component in the resin component of the toner is less than 2% by weight, the releasability is impaired.
The toner may flow (flow out) at the time of high-temperature fixing, and when the content of the toluene-insoluble component exceeds 30% by weight, the toner hardly deforms at the time of fixing and melting, and the low-temperature fixing property is reduced.

In the present invention, the content of the toluene-insoluble component in the resin component of the toner is determined based on the weight of the extraction residue after extracting the toner with a toluene solvent for 20 hours using a Soxhlet extractor used for the GPC measurement described above. The value obtained by subtracting the weight of the colorant and the charge control agent from the weight of the toner before Soxhlet extraction is divided by the weight of the toner before the Soxhlet extraction minus the weight of the colorant and the charge control agent is multiplied by 100.

More specifically, the content of the toluene-insoluble component of the resin component in the present invention is specifically determined by the following measurement method.

A sample of 1 g was placed on a cylindrical filter paper (Toyo Filter Paper, No. 8).
6R). This is immersed in 1 liter of toluene, and extracted for 20 hours in a boiling state. The filter paper after extraction is dried and weighed, and the toluene-insoluble component is calculated based on the following formula.

[0098]

[Outside 1] W ₀ : Weight of thimble filter paper (g) W ₁ : Weight of (sample + thimble filter paper) before extraction (g) W ₂ : Weight of thimble filter paper after extraction and drying (g) Components other than resin component are contained in the sample when being calculates a toluene insoluble components using the weight W ₁ 'and weight W _2' obtained by subtracting the weight of the components other than the respective resin components from the weight W ₁ and W _2.

Examples of the low softening point substance which is a release agent used in the toner for developing an electrostatic image of the present invention include polymethylene wax such as paraffin wax, polyolefin wax, microcrystalline wax and Fischer-Tropsch wax; amide wax Higher fatty acids; long-chain alcohols; ester waxes; and derivatives thereof such as graft compounds and block compounds. These preferably have a sharp endothermic peak in a DSC endothermic curve from which low molecular weight components have been removed.

Preferred waxes include linear alkyl alcohols, linear fatty acids, linear acid amides, linear esters, and montan derivatives having a unit number of 15 to 100. It is also preferable that impurities such as liquid fatty acids have been removed from these waxes in advance.

Further, preferably used wax is
Low-molecular weight alkylene polymer obtained by radical polymerization of alkylene under high pressure or low pressure using Ziegler catalyst or other catalyst; alkylene polymer obtained by thermally decomposing high molecular weight alkylene polymer; A product obtained by separating and purifying a low-molecular-weight alkylene polymer as a by-product; from a distillation residue of a hydrocarbon polymer obtained by the Age method from a synthesis gas comprising carbon monoxide and hydrogen, or a synthetic carbon obtained by hydrogenating the distillation residue. A polymethylene wax obtained by extracting and separating a specific component from hydrogen can be used. An antioxidant may be added to these waxes.

The release agent used in the present invention has a maximum endothermic peak in a temperature range of preferably 40 to 120 ° C., more preferably 40 to 90 ° C., and still more preferably 45 to 85 ° C. in a DSC endothermic curve. It is preferred to have. When the maximum endothermic peak is less than 40 ° C., the self-cohesive force of the low softening point substance becomes weak, and as a result, the high temperature offset resistance becomes weak, which is not preferable. If the maximum endothermic peak exceeds 120 ° C., the fixing temperature becomes high, and further, a substance having a low softening point precipitates during granulation, which disturbs the suspension system, which is not preferable.

Further, a low melting point substance having a sharp melting property having a maximum endotherm of the release agent (the peak has a half width of preferably within 10 ° C., more preferably within 5 ° C.) is preferable.

In the present invention, the DSC measurement of the release agent
Performed in accordance with ASTM D3418-8.

More specifically, for example, DSC-7 manufactured by Perkin Elmer Co., Ltd. was used. The temperature of the detector was corrected using the melting points of indium and zinc, and an empty pan was set for comparison.
The measurement was performed at a rate of 10 ° C./min from 0 ° C. to 200 ° C.

In particular, as the release agent, a C 15-45 carbon atom
Wax composed mainly of an ester compound of a long-chain alkyl alcohol and a long-chain alkyl carboxylic acid having 15 to 45 carbon atoms has transparency in an OHP sheet, low-temperature fixability during fixing, and high-temperature offset resistance It is preferable from the point of view.

In the present invention, the content of the release agent is preferably from 3 to 40 parts by weight based on 100 parts by weight of the binder resin of the toner.
Parts by weight, more preferably 5 to 35 parts by weight,
It is good in terms of offset resistance and stability during toner production.

When the content of the release agent in the toner is less than 3 parts by weight, it is difficult to obtain a sufficient high-temperature offset property, and when the image is fixed on both sides of the recording material, the first time is fixed at the second time (back side). A second (front) image offset may occur. When the content of the release agent exceeds 40 parts by weight,
When toner particles are produced by a pulverization method during the production of a toner, fusion of the toner components into the toner production apparatus is apt to occur, and when the toner particles are produced by a polymerization method, the granulation property during granulation is low. At the same time, the toner particles tend to coalesce.

It is preferable that the release agent is included in the toner particles from the viewpoint of durability. As a specific method of enclosing the release agent, the polarity of the material in the aqueous medium is set to be smaller than that of the main polymerizable monomer in the release agent, and a small amount of a large polar resin or a weight unit By adding the particles, toner particles having a core / shell structure in which the core surface of the release agent is covered with the shell of the outer shell resin can be obtained.

As a specific method for confirming the core / shell structure of the toner particles, the toner particles were sufficiently dispersed in a room temperature curable epoxy resin and then cured in an atmosphere at a temperature of 40 ° C. for 2 days. Ruthenium tetroxide,
After dyeing with osmium tetroxide, if necessary, a flaky sample is cut out using a microtome provided with diamond teeth, and the tomographic morphology of the toner particles is observed using a transmission electron microscope (TEM). In the present invention, it is preferable to use a ruthenium tetroxide dyeing method in order to provide a contrast between materials by utilizing a slight difference in crystallinity between the release agent used and the resin constituting the outer shell.

The toner of the present invention is preferably a polymerized toner obtained by a polymerization method for producing toner particles by polymerizing a polymerizable monomer composition. Polymerized toner has no problems such as breaking of molecular chains of high molecular weight components and pulverizability which occur in processes such as melt-kneading and pulverization in the production of pulverized toner, and it is possible to control the ratio of each component which is a feature of the present invention. Because it is easy.

In the case of producing toner particles by a polymerization method,
Control of the particle size distribution and particle size of the toner can be achieved by changing the type and amount of a poorly water-soluble inorganic salt added to the aqueous medium or a dispersant that acts as a protective colloid; used during granulation in the aqueous medium It can be appropriately controlled by mechanical device conditions, for example, stirring conditions such as the peripheral speed of the rotor, the number of passes, the shape of the stirring blades, and the shape of the container; and by controlling the solid concentration in the aqueous solution.

Examples of the polymerizable monomer used in the present invention include styrene, o (m-, p-)-methylstyrene,
Styrene-based monomers such as (p-)-ethylene styrene;
(Meth) acrylic acid monomer; methyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate (Meth) acrylate monomers such as behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate; butadiene, isoprene, Ene monomers such as cyclohexene, (meth) acrylonitrile and acrylamide are preferably used.

These polymerizable monomers may be used alone or generally in a published polymer handbook, 2nd edition -P139-
192 (manufactured by John Wiley & Sons) and monomers are appropriately mixed and used so that the theoretical glass transition temperature (Tg) thereof is 40 to 80 ° C. If the theoretical glass transition temperature is less than 40 ° C., problems arise in terms of the storage stability of the toner and the durability stability of the developer.
When the temperature exceeds 0 ° C., the fixing point rises. In particular, in the case of a full-color toner, the color mixture of each color toner is insufficient, resulting in poor color reproducibility. Not preferred.

In the present invention, when producing toner particles having a core / shell structure by a polymerization method, it is preferable to add a polar resin. As the polar resin used in the present invention, a copolymer of styrene (meth) acrylic acid, a maleic acid copolymer, a polyester resin, and an epoxy resin are preferably used. It is particularly preferable that the polar resin does not contain an unsaturated group capable of reacting with the polymerizable monomer in the molecule.

In the present invention, an outermost resin layer may be further provided on the surface of the toner particles. The glass transition temperature of the outermost shell resin layer is set to be equal to or higher than the glass transition temperature of the outer shell resin layer constituting the shell to further improve the blocking resistance, and the glass transition temperature is crosslinked to the extent that the fixability is not impaired. Is preferred. It is preferable that the outermost resin layer contains a polar resin and a charge control agent for improving the chargeability.

The method for providing the outermost shell resin layer is not particularly limited, and examples thereof include the following methods.

[0118] 1. In the latter half or end of the polymerization reaction, if necessary in the reaction system, a monomer in which a polar resin, a charge control agent, a cross-linking agent, etc. are dissolved and dispersed is added, the mixture is adsorbed on polymer particles, and a polymerization initiator is added to perform polymerization. Method.

[0119] 2. If necessary, add emulsion polymerization particles or soap-free polymerization particles composed of monomers containing a polar resin, a charge control agent, and a cross-linking agent into the reaction system, and agglutinate on the surface of the polymerization particles. How to let.

[0120] 3. A method in which emulsion polymerized particles or soap-free polymerized particles comprising a monomer containing a polar resin, a charge control agent, and a cross-linking agent are mechanically fixed to the toner particle surface in a dry system, if necessary.

As the polar resin, a polyester resin is preferable.

As the colorant used in the present invention, a black colorant obtained by using carbon black, a magnetic substance, and the following chromatic colorants of yellow / magenta / cyan as black colorants is used.

Examples of the yellow colorant include condensed azo compounds, isoindolinone compounds, anthraquinone compounds,
A compound represented by an azo metal complex, a methine compound or an allylamide compound is used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 6
2, 74, 83, 93, 94, 95, 109, 110,
111, 128, 129, 147, 168 and 180 are preferably used.

Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazole compounds, thioindigo compounds and perylene compounds. Specifically, C.I.
I. Pigment Red 2, 3, 5, 6, 7, 23, 4
8: 2, 48: 3, 48: 4, 57: 1, 81: 1, 1
22, 144, 146, 166, 169, 177, 18
4, 185, 202, 206, 220, 221, 254
Is particularly preferred.

As the cyan colorant used in the present invention, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds and basic dye lake compounds can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 1
5: 1, 15: 2, 15: 3, 15: 4, 60, 62,
66 and the like can be particularly preferably used.

These colorants can be used alone or as a mixture, or in the form of a solid solution.

When the colorant of the present invention is a color toner,
The selection is made in consideration of hue angle, saturation, lightness, weather resistance, OHP transparency, and dispersibility in toner particles. The amount of the coloring agent is preferably 1 to 100 parts by weight of the binder resin.
Used in an amount of up to 20 parts by weight.

When a magnetic material is used as the black colorant, unlike the case where other colorants are contained, the binder resin 10
It is preferably used by adding 40 to 150 parts by weight to 0 parts by weight.

The charge control agents used in the present invention include:
Known colorants can be used, but in the case of a color toner, a charge control agent that is particularly colorless, has a high toner charging speed, and can stably maintain a constant charge amount is preferable.
Furthermore, in the case of a toner obtained by a polymerization method, a charge control agent having no polymerization inhibition and having no solubilized substance in an aqueous system is particularly preferable.

Specific compounds include salicylic acid, naphthoic acid, dicarboxylic acid, metal compounds of their derivatives, sulfonic acid, high molecular compounds having carboxylic acid in the side chain, boron compounds, urea compounds, and silicon compounds as negative compounds. And calixarene, and a quaternary ammonium salt, a high molecular compound having the quaternary ammonium salt in a side chain, a guanidine compound, and an imidazole compound can be used as the positive system.

The charge control agent is preferably used in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the binder resin. However, in the present invention, the addition of a charge control agent is not essential. For example,
In the case of using a two-component developing method, frictional charging with a carrier is used, and in the case of using a one-component developing method, frictional charging with a blade member or a sleeve member is actively used. It is not always necessary to include a charge control agent in the toner particles.

Examples of the polymerization initiator used in the present invention include, for example, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutylnitrile,
1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-
Azo polymerization initiators such as dimethylvaleronitrile and azobisisobutylnitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroxy peroxide;
A peroxide-based polymerization initiator such as 2,4-dichlorobenzoyl peroxide and lauroyl peroxide is used.

The amount of the polymerization initiator to be added varies depending on the target component ratio of the present invention, but is generally from 0.5 to 20% by weight, more preferably from 0.5 to 20% by weight, based on the polymerizable monomer. 10
% By weight. The type of the initiator slightly varies depending on the polymerization method, but is used alone or in combination with reference to the 10-hour half-life temperature.

In the toner of the present invention, for example, by reducing the amount of the initiator, the amount of the initiator acting as a chain transfer agent is reduced, and the resin component having a molecular weight of 300,000 or more is positively synthesized. In a reaction system in which it has been confirmed that a polymer having a molecular weight of 2,000 to 5,000 hardly grows because the molecular growth reaction lasts for a long time, a weight having a top peak between molecular weights of 2,000 to 5,000 is added. It can be obtained by adding an appropriate amount of the coalescence to the monomer composition before granulation. In addition, for example, polymerization is carried out at a temperature of 40 ° C. or higher, more preferably 50 to 90 ° C. for a certain period of time to synthesize a high molecular weight polymer in the first half of the polymerization reaction, and then the temperature is raised with a gentle temperature gradient. It can be obtained by synthesizing an optimal low molecular weight compound.

In each case, the concentration of dissolved oxygen in the aqueous medium during the polymerization reaction is preferably 0.1 to 0.8 mg / l.
It is better to control strictly so that The control of the dissolved oxygen concentration can be performed by bubbling nitrogen into the aqueous medium.

In the present invention, in order to control the molecular weight distribution of the resin component of the toner, it is preferable to further use a known crosslinking agent, chain transfer agent and polymerization inhibitor.

When suspension polymerization is used to obtain the toner of the present invention, any of an inorganic compound and an organic compound can be used as a dispersant.

Examples of the inorganic compounds include calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, and calcium metasilicate. , Calcium sulfate,
Examples include barium sulfate, bentonite, silica, alumina, magnetic materials, and ferrite.

Examples of the organic compound include polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, and starch.

These dispersants are used in the polymerizable monomer composition 10
It is preferable to use 0.2 to 10 parts by weight with respect to 0 parts by weight.

As these dispersants, commercially available ones may be used as they are, but in order to obtain finely dispersed particles having a uniform particle size, the inorganic compound is formed under high-speed stirring in a dispersion medium. You can also get.

For example, in the case of a calcium phosphate salt, a dispersant suitable for a suspension polymerization method can be obtained by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring.

These dispersants may be used in combination with 0.001 to 0.1 parts by weight of a surfactant. Specifically, commercially available nonionic, anionic, and cationic surfactants can be used, for example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, and olein. Calcium acid is preferably used.

In the present invention, a method for producing a polymerized toner is as follows: a mold release agent, a colorant, a charge control agent, a polymerization initiator and other additives are added to a polymerizable monomer; The monomer composition uniformly dissolved or dispersed by a mixer as described above is dispersed in an aqueous phase containing a dispersion stabilizer by a disperser such as a homomixer. The granulation is stopped when the desired toner particle size is obtained from the droplets of the monomer composition. After that, by the action of the dispersion stabilizer, stirring may be performed to such an extent that the particle state is maintained and the particles are prevented from settling. The polymerization is performed at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. In the present invention, for the purpose of controlling the molecular weight distribution, the temperature may be raised in the latter half of the polymerization reaction.
In order to remove unreacted polymerizable monomers and by-products, the aqueous medium may be partially distilled off in the latter half of the reaction or after the completion of the reaction. After the reaction, the generated toner particles are collected by washing and filtration, and dried. In the suspension polymerization method, it is usually preferable to use 300 to 3,000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer composition.

To produce the toner of the present invention, in addition to the above polymerization method, a binder resin, a release agent, a colorant, a charge control agent and other additives are added to a pressure kneader, an extruder or a medium dispersion. After uniformly dispersing using a disperser such as a disperser, finely pulverizing to a desired toner particle size by a mechanical pulverizer or a collision type pulverizer that collides with a target under a jet stream, followed by a classification step The toner particles can be obtained by a so-called pulverization method in which the particle size distribution is sharpened to form a toner.

The external additive externally added to the toner particles for the purpose of imparting various toner properties has an average particle diameter of 1/10 or less of the weight average particle diameter of the toner particles from the viewpoint of the durability of the toner. Is preferred. The average particle size of this additive is
It means the number average particle diameter obtained by observing the surface of the toner particles with an electron microscope.

As the external additives, for example, the following are used.

For example, metal compounds (aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, tin oxide, zinc oxide), nitrides (silicon nitride), carbides (silicon carbide), metal salts (sulfuric acid) Calcium, barium sulfate, calcium carbonate),
Fatty acid metal salts (zinc stearate, calcium stearate), carbon black and silica.

The amount of these external additives is preferably 0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the toner particles. These external additives may be used alone or in combination. It is more preferable that the external additive has been subjected to a hydrophobic treatment.

In the present invention, the toner particles preferably have a weight average particle diameter (D ₄ ) of preferably _{4 to} 10 μm, more preferably 5 to 8 μm, and a finer latent particle for achieving high image quality. It is good in that the image dots can be faithfully reproduced.
When the weight average particle diameter (D ₄ ) of the toner particles is less than 4 μm, the transfer efficiency is reduced, the transfer residual toner on the surface of the photoreceptor is increased, and unevenness of the image is likely to occur.
When the weight average particle diameter (D ₄ ) of the toner particles exceeds 10 μm, re-imageability of fine dots is reduced and image quality is reduced. In addition, fusing to various members due to the toner coefficient is likely to occur.

The weight average particle size of the toner particles is measured using a Coulter Counter TA-II or a Coulter Multisizer (manufactured by Coulter Inc.). In the present invention, a Coulter Counter TA-II type (manufactured by Coulter) is used, and an interface (manufactured by Nikkaki) for outputting the number distribution and volume distribution is connected to a PC9801 personal computer (manufactured by NEC). A 1% NaCl aqueous solution is prepared using sodium chloride. For example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the electric field aqueous solution.
Add g. The electrolyzed solution in which the sample is suspended
Disperse for ~ 3 minutes and carry out Coal Tarinter TA
A volume distribution and a number distribution were calculated by measuring the volume and the number of toner particles of 2 μm or more by using a 100 μm aperture as an aperture according to type-II. Then, a volume-based weight average particle size (D ₄ : the median value of each channel is a representative value of the channel) obtained from the volume distribution according to the present invention was obtained.

The above-described toner of the present invention can be used as a one-component developer or as a two-component developer by mixing toner and carrier particles.

Examples of the carrier particles of the two-component developer include:
For example, surface oxidized or unoxidized iron, nickel, copper, zinc,
Magnetic metals such as cobalt, manganese, chromium, rare earths,
Their alloys, their oxides and ferrites can be used. There is no special restriction on the manufacturing method.

Further, it is preferable to coat the surface of the carrier particles with a coating material having a resin for the purpose of charge adjustment and the like. As the method, any of conventionally known methods such as a method of dissolving or suspending a coating material having a resin in a solvent, coating and adhering to a carrier, or a method of simply mixing with a powder can be applied. In order to stabilize the composition, a method in which the coating material is dissolved in a solvent and applied is more preferable.

As the coating material on the surface of the carrier,
Depending on the toner material, for example, an aminoacrylate resin, an acrylic resin, or a copolymer of such a resin and a styrene-based resin is preferable.

As the resin for forming the negatively chargeable coating material, silicone resin, polyester resin, fluororesin, polytetrafluoroethylene, monochlorotrifluoroethylene polymer, and polyvinylidene fluoride are located on the negative side in the charging series. Although preferred, it is not necessarily limited to this. The coating amount of these compounds may be appropriately determined so as to satisfy the charge imparting characteristics of the carrier, but is generally preferably 0.1 to 30% by weight, more preferably 0.3 to 20% by weight based on the total amount of the carrier. Good to be.

As the material of the carrier used in the present invention, 98% or more of Cu—Zn—Fe (composition ratio [5-2]
0]: [5 to 20]: Ferrite particles having a composition of [30 to 80] are typical, but there are no restrictions unless the performance is impaired. Further, it may be in the form of a resin carrier composed of a binder resin, a metal oxide, and a magnetic metal oxide.

The average particle size of these carriers is preferably 3
The thickness is preferably 5 to 65 μm, more preferably 40 to 60 μm. Furthermore, the content of particles having a particle size of 26 μm or less in a volume distribution is 2 to 6%, the content of particles having a particle size of 35 to 43 μm is 5% to 25%, and the content of particles having a particle size of 74 μm or more. Is less than 2%, a good image can be formed.

Good results can be obtained when the mixing ratio of the above-mentioned carrier and toner particles is 2 to 9% by weight, preferably 3 to 8% by weight as the toner concentration in the two-component developer. If the toner concentration is less than 2% by weight, the image density is low and it becomes impractical.

The average particle size of the carrier can be measured using a commercially available dry particle size distribution analyzer. Specifically, the dry dispersion is applied to a laser diffraction type particle size analyzer HEROS (manufactured by JEOL Ltd.). Device RODOS (manufactured by JEOL Ltd.)
And the measurement is performed three times for each sample under the condition of a dispersion pressure of 3.0 bar, and the average value of the 50% particle size based on the volume distribution is defined as the average particle size.

The image forming method using the toner of the present invention will be described below with reference to the accompanying drawings.

FIG. 7 is a schematic view of an image forming apparatus capable of performing the image forming method of the present invention.

A first image forming unit Pa, a second image forming unit Pb, a third image forming unit Pc, and a fourth image forming unit Pd are provided in the main body of the image forming apparatus.
Images of different colors are formed on the transfer material through the processes of latent image, development, and transfer.

The structure of each image forming unit provided in the image forming apparatus will be described with reference to the first image forming unit P shown in FIG.
This will be described using a as an example.

The first image forming unit Pa has an electrophotographic photosensitive drum 1a as a latent image holding member, and the photosensitive drum 1a is rotated in the direction of arrow a. Reference numeral 2a denotes a primary charger as a charging unit, and the photosensitive drum 1a
And a contact charging roller is used. Reference numeral 17a denotes a polygon mirror which scans by rotating a laser beam as a latent image forming means for forming an electrostatic latent image on the photosensitive drum 1a whose surface is uniformly charged by the primary charger 2a. Reference numeral 3a denotes a developing device as developing means for developing a latent image formed on the photosensitive drum 1a to form a color toner image, and holds a color toner of each color. Reference numeral 4a denotes a transfer blade as a transfer unit for transferring the color toner image formed on the surface of the photosensitive drum 1a to the surface of a recording material 6 as a transfer material conveyed by a bet-like recording material carrier 8. The transfer blade 4a can apply a transfer bias by contacting the back surface of the recording material carrier 8.

Reference numeral 21a denotes an erase exposure device as a discharging means for discharging the surface of the photosensitive drum 1a.

The first image forming unit Pa uniformly and primary charges the photosensitive member of the photosensitive drum 1a by the primary charger 2a, and then forms an electrostatic latent image on the photosensitive member by the latent image forming means 17a. A developing device 3a develops the electrostatic latent image using color toner, and the developed toner image is belt-shaped to carry and transport the recording material 6 at a first transfer portion (contact position between the photosensitive member and the recording material). A transfer bias is applied from a transfer blade 4a that comes into contact with the back surface of the recording material carrier 8 to transfer the image onto the surface of the transfer material 6.

The color toner present on the photoreceptor can be removed from the photoreceptor by a cleaning means such as a cleaning blade in contact with the surface of the photoreceptor, but is collected by the developing means during development.
Therefore, the photoreceptor having the transfer residual toner is neutralized by the erase exposure device 21a, and the image forming process is performed again.

As shown in FIG. 7, the image forming apparatus has the same structure as the first image forming unit Pa as described above, and the second image forming apparatus having different colors of the color toner held in the developing device. A unit Pb, a third image forming unit Pc, and a fourth image forming unit Pd are provided side by side. For example, the first image forming unit Pa includes magenta toner, the second image forming unit Pb includes cyan toner, and the third image forming unit Pc.
Then, the yellow toner and the black toner are used for the fourth image forming unit Pd, respectively, and the transfer of each color toner onto the transfer material is sequentially performed in the transfer unit of each image forming unit. In this step, while the registration is being performed, each color toner is superimposed on the same recording material by one movement of the recording material, and when the recording is completed, the recording material 6 is separated from the recording material carrier 8 by the separation charger 14. Then, the sheet is sent to the fixing unit 7 by a conveying means such as a conveying belt, and a final full-color image is obtained by a single fixing.

The fixing device 7 has a pair of fixing rollers 71 and a pressure roller 72. Each of the fixing roller 71 and the pressure roller 72 has heating means 75 and 76 inside. Reference numerals 73 and 74 denote wedges for removing dirt on the fixing rollers. Reference numeral 77 denotes an application roller as oil applying means for applying a release oil 78 such as silicone oil to the surface of the fixing roller 71.

The unfixed color toner image transferred onto the recording material 6 passes through the pressure contact portion between the fixing roller 71 and the pressure roller 72 of the fixing device 7, so that the recording material is acted upon by heat and pressure. 6 is fixed.

In FIG. 7, the recording material carrier 8 is an endless belt-shaped member, which is moved in the direction of arrow e by ten drive rollers. 9 is a transfer belt cleaning device, 11 is a belt driven roller, and 12 is a belt static eliminator. Reference numeral 13 denotes a pair of registration rollers 13 for conveying the recording material 6 in the recording material holder 60 to the recording material carrier 8. Reference numeral 17 denotes a polygon mirror, which scans a laser beam emitted from a light source device (not shown) by the polygon mirror, and includes an fθ lens that condenses the scanning light, which is deflected by a reflection mirror, on the generatrix of the photosensitive drum. A latent image is formed in accordance with the image signal via the CPU.

In the present invention, as a charging means for primary charging of the photoreceptor, a contact charging member such as a roller, a blade or a magnetic brush for charging by contacting the photoreceptor is used. Although it is preferable to control the generation amount, it is also possible to use a non-contact charging unit such as a corona charger which charges the photoconductor in a non-contact manner.

The transfer means is a contact transfer in which a transfer bias can be directly applied by contacting the back surface of the recording material support such as a roller-shaped transfer roller instead of the transfer blade contacting the back surface of the recording material support. Means can be used.

Further, in place of the above-mentioned contact transfer means, a non-contact type in which a transfer bias is applied by a transfer bias from a corona charger arranged in a non-contact manner on the back side of a generally used recording material carrier to perform transfer. May be used.

However, it is more preferable to use the contact transfer means because the amount of ozone generated during the transfer bias can be controlled.

The above-described image forming apparatus employs an image forming method of a type in which a toner image formed on a latent image holding member is directly transferred to a recording material without using an intermediate transfer member.

Next, the toner image formed on the latent image holding member is subjected to a first transfer to an intermediate transfer member, and the toner image transferred to the intermediate transfer member is subjected to a second transfer to a recording material. The forming method will be described using the image forming apparatus shown in FIG.

In FIG. 9, a charging roller 142 rotates in contact with a photosensitive drum 141 serving as a latent image holding member.
To give a surface potential on the photosensitive drum 141 to form an electrostatic latent image by the exposure means 143. The electrostatic latent image is developed by magenta toner, cyan toner, yellow toner, and black toner by developing units 144, 145, 146, and 147 to form a toner image. The toner image is transferred onto the intermediate transfer member 148 for each color, and is repeated a plurality of times to form a multiple toner image.

As the intermediate transfer member 148, a drum-shaped one is used, and a holding member is stretched on the outer peripheral surface, and a conductivity-imparting member such as carbon black, zinc oxide, tin oxide, silicon carbide or titanium oxide is provided on a base material. A material having an elastic layer (for example, nitrile butadiene rubber) in which the above components are sufficiently dispersed is used. A belt-shaped intermediate transfer member may be used.

The intermediate transfer member 148 is composed of the elastic layer 150 having a hardness of 10 to 50 degrees (JIS K-6301). In the case of a transfer belt, the intermediate transfer member 148 has this hardness at the second transfer portion to the recording material. Support member 15 having elastic layer 150
5 is preferable.

From the photosensitive drum 141 to the intermediate transfer member 148
The transfer to the toner image is performed by applying a bias from a power source 149 to a core bar 155 as a support member of the intermediate transfer member 148 to obtain a transfer current. Corona discharge or roller charging from the back of the holding member or belt may be used.

The multiple toner image on the intermediate transfer member 148 is
The image is transferred onto the recording material S at once by the transfer means 151. As the transfer unit, a contact electrostatic transfer unit using a corona charger, a transfer roller, or a transfer belt is used.

The recording material S having the toner image is
Fixing Roller 15 as Fixing Member Having 56 Inside
7 and a pressure roller 1 that is in pressure contact with the fixing roller 157
When the recording material S passes through the contact nip between the fixing roller 157 and the pressure roller 158 of the heat fixing device having the fixing member 58, the toner image is fixed on the recording material S.

Next, the structure of a developing device usable in the present invention will be described in detail with reference to the drawings.

In the present invention, a contact development method in which a developer carried on a developer carrier is brought into contact with the surface of a photoreceptor in a development area to perform development, and a development method in which a developer carrier is carried on the surface of a photoreceptor in a development area Any of the non-contact jumping development systems in which the developing agent is made to fly from a developer carrying member set at an interval such that the photoconductor and the developer layer are not in contact with each other to perform development can be used.

Examples of the contact development method include a development method using a two-component developer having a toner and a carrier and a development method using a one-component developer.

As the contact two-component developing method, a two-component developer obtained by mixing a toner and a magnetic carrier is used, for example, as shown in FIG.
The development can be performed using the developing device 120 as shown in FIG.

The developing device 120 includes a two-component developer 128.
, A developing sleeve 121 as a developer carrying member for carrying the two-component developer 128 contained in the developing container 126 and transporting the developer to the developing area;
A developing blade 127 as a developer layer thickness regulating unit for regulating the thickness of the toner layer formed on the developing sleeve 121 is provided.

The developing sleeve 121 has a magnet 123 inside a non-magnetic sleeve base 122.

The inside of the developing container 126 is divided into a developing chamber (first chamber) R ₁ and a stirring chamber (second chamber) R ₂ by a partition 130, and the toner is disposed above the stirring chamber R ₂ via the partition 130. storage chamber R ₃ is formed. The developing chamber R ₁ and the stirring chamber R in ₂ is accommodated developer 128, the replenishing toner (non-magnetic toner) 129 is stored in the toner storage chamber R _3. Note that the toner storage chamber R ₃ replenishing port 13
1 is provided, replenishment toner 129 quantities commensurate with the toner consumed through the supply port 131 is dropped replenished into the stirring chamber R _2.

[0192] A conveying screw 124 in the developing chamber R ₁ provided, the developer 128 in the developing chamber R ₁ by the driving rotation of the conveying screw 124 is conveyed toward the longitudinal direction of the developing sleeve 121 . Similarly, a transfer screw 125 is provided in the stirring chamber R ₂ , and the rotation of the transfer screw 125 causes the supply port 131 or the stirring chamber R to rotate.
_The toner that has fallen into ₂ is transported along the longitudinal direction of developing sleeve 121.

The developer 128 is a two-component developer having a non-magnetic toner and a magnetic carrier.

An opening is provided in a portion of the developing container 126 close to the photosensitive drum 119, and the developing sleeve 121 is discharged to the outside from the opening, and a gap is provided between the developing sleeve 121 and the photosensitive drum 119. Is provided. A bias applying unit 132 for applying a bias is arranged on the developing sleeve 121 made of a non-magnetic material.

A magnet roller as a magnetic field generating means fixed to the sleeve base 122, ie, a magnet 123,
As described above, the developing magnetic pole S ₁ , the magnetic pole N ₃ located downstream thereof, and the magnetic poles N ₂ , S
₂ , N ₁ . The magnet 123 is provided on the sleeve base 122 so that the developing magnetic pole S ₁ is opposed to the photosensitive drum 119.
Is located within. The developing magnetic pole S ₁ is the developing sleeve 1
A magnetic field is formed near the developing unit between the photoconductor 21 and the photoconductor drum 119, and the magnetic field forms a magnetic brush.

The regulating blade 127 disposed above the developing sleeve 121 and regulating the layer thickness of the developer 128 on the developing sleeve 121 is made of a non-magnetic material such as aluminum or SUS316. The distance A between the end of the non-magnetic blade 127 and the surface of the developing sleeve 121 is 300 to 100.
0 μm, preferably 400 to 900 μm. If this distance is less than 300 μm, the magnetic carrier is clogged during this time, and the developer layer is likely to be uneven, and the developer required for good development cannot be applied, and the density of the developed image is low and uneven. There is a problem that only can be obtained. In order to prevent uneven application (so-called blade jam) due to unnecessary particles mixed in the developer, 4
It is preferably at least 00 μm. If the thickness is larger than 1000 μm, the amount of the developer applied on the developing sleeve 121 increases, and a predetermined thickness of the developer layer cannot be regulated. As a result, the adhesion of the magnetic carrier particles to the photosensitive drum 119 increases, and the developer circulates. There is a problem that the development regulation by the non-magnetic developing blade 127 is weakened, and toner tribo is insufficient and fogging is likely to occur.

In the development of the two-component developing device 120, a state in which an alternating electric field is applied and a magnetic brush latent image carrier (for example, a photosensitive drum) 119 composed of a toner and a magnetic carrier is in contact with the toner. It is preferable to carry out development. The distance (S-D distance) B between the developer carrier (developing sleeve) 121 and the photosensitive drum 119 is 100 to 10
The thickness of 00 μm is favorable in preventing carrier adhesion and improving dot reproducibility. If it is smaller than 100 μm, the supply of the developer tends to be insufficient and the image density is lowered. If it is larger than 1000 μm, the magnetic force lines from the magnet S ₁ are widened and the density of the magnetic brush is reduced, resulting in poor dot reproducibility or poor carrier performance. The binding force is weakened and carrier adhesion is likely to occur.

The voltage between the peaks of the alternating electric field is 500 to 50.
00V is preferable, the frequency is 500 to 10000 Hz,
The frequency is preferably 500 to 3000 Hz, and can be appropriately selected and used for each process. In this case, a triangular wave, a rectangular wave, a sine wave, or a waveform having a changed duty ratio can be used as the waveform. If the applied voltage is lower than 500 V, it is difficult to obtain a sufficient image density, and it may not be possible to satisfactorily collect the fog toner in the non-image area. If the voltage exceeds 5000 V, the electrostatic image may be disturbed via the magnetic brush, which may cause deterioration in image quality.

By using a two-component developer having a well-charged toner, the fog removal voltage (Vback) can be reduced.
And the primary charge of the photoconductor can be reduced, so that the life of the photoconductor can be extended. Vbac
k is preferably 150 V or less, more preferably 100 V or less, depending on the developing system.

As the contrast potential, 200 V to 500 V is preferably used so that a sufficient image density can be obtained.

If the frequency is lower than 500 Hz, it depends on the process speed. However, since charge injection into the carrier occurs, the image quality may be degraded by carrier adhesion or disturbing the latent image. If the frequency exceeds 10,000 Hz, the toner cannot follow the electric field, and the image quality is likely to deteriorate.

The contact width (developing nip C) of the magnetic brush on the developing sleeve 121 with the photosensitive drum 119 is preferably 3 in order to obtain a sufficient image density, have excellent dot reproducibility, and perform development without carrier adhesion. ８8 mm. If the developing nip C is smaller than 3 mm, it is difficult to sufficiently satisfy a sufficient image density and dot reproducibility. If the developing nip C is larger than 8 mm, packing of a developer occurs and the operation of the machine is stopped or the carrier adheres. It is difficult to sufficiently suppress this. As a method of adjusting the developing nip, the nip width is appropriately adjusted by adjusting the distance A between the developer regulating member 127 and the developing sleeve 121 or adjusting the distance B between the developing sleeve 121 and the photosensitive drum 119.

Incidentally, the transfer residual toner on the photoreceptor is collected at the time of development by a magnetic brush composed of the toner and the carrier of the developing device.

As the contact one-component developing method, it is possible to develop using a non-magnetic toner, for example, using a developing device 80 as shown in FIG.

The developing device 80 carries a developing container 81 containing a one-component developer 88 having a magnetic or non-magnetic toner, and carries the one-component developer 88 contained in the developing container 81 and transports it to the developing area. Roller 82 for supplying developer to developer carrier 82 for supplying toner to developer carrier
5. Elastic blade 86 as a developer layer thickness regulating member for regulating the thickness of the developer layer on the developer carrier, and developing container 8
1 has a stirring member 87 for stirring the developer 88.

As the developer carrying member 82, an elastic layer 8 formed on a roller base 83 by an elastic member such as rubber or resin having elasticity such as foamed silicone rubber.
It is preferred to use an elastic roller having 4.

The elastic roller 82 is brought into pressure contact with the surface of a photosensitive drum 89 as a latent image holding member, and electrostatically formed on the photosensitive member by a one-component developer 88 applied to the surface of the elastic roller. While developing the latent image, an unnecessary one-component developer 88 existing on the photoreceptor after transfer is collected.

In the present invention, the developer carrying member is substantially in contact with the photosensitive member surface. This means that the developer carrier is in contact with the photoconductor when the one-component developer is removed from the developer carrier. At this time, an image having no edge effect is obtained by an electric field acting between the photoconductor and the developer carrier via the developer, and at the same time, cleaning is performed. There is a need to have an electric potential between the surface of the elastic roller or the vicinity of the surface as a developer carrier and an electric field between the surface of the photosensitive member and the surface of the elastic roller. For this reason, it is also possible to use a method in which the elastic rubber of the elastic roller is resistance-controlled in the medium resistance region to keep the electric field while preventing conduction with the photoreceptor surface, or a thin dielectric layer is provided on the surface layer of the conductive roller. . Furthermore, a conductive layer is provided on the conductive roller on a conductive resin sleeve in which the surface on the outer surface in contact with the photoreceptor surface is coated with an insulating material or on an inner surface which is not in contact with the photoreceptor with an insulating sleeve. Other configurations are also possible.

The elastic roller carrying the one-component developer may rotate in the same direction as the photosensitive drum or in the opposite direction. When the rotation is in the same direction, it is preferable that the peripheral speed ratio is greater than 100% with respect to the peripheral speed of the photosensitive drum. If it is less than 100%, problems tend to occur in image quality such as poor line clarity. As the peripheral speed ratio increases, the amount of the developer supplied to the developing site increases, and the frequency of attaching and detaching the developer to the electrostatic latent image increases.
An unnecessary portion of the developer is scraped off, and the necessary portion is repeatedly supplied with the developer, whereby an image faithful to the electrostatic latent image is obtained. More preferably, the peripheral speed ratio is 100
% Or more is good.

The developer layer thickness regulating member 186 is not limited to an elastic blade, but may be an elastic roller as long as it is in pressure contact with the surface of the developer carrying member 182 by elastic force.

As the elastic blade and elastic roller, rubber elastic bodies such as silicone rubber, urethane rubber and NBR; synthetic resin elastic bodies such as polyethylene terephthalate; metal elastic bodies such as stainless steel and steel can be used. Further, even a complex thereof can be used.

In the case of an elastic blade, the base on the upper side of the elastic blade is fixed and held on the developer container side, and the lower side is bent in the forward or reverse direction of the developing sleeve against the elasticity of the blade. In this state, the inner surface of the blade (the outer surface in the case of the opposite direction) is brought into contact with the sleeve surface with moderate elastic pressure.

[0213] The supply roller 85 is made of a foam material such as polyurethane foam.
The developer rotates in a forward or reverse direction at a relative speed other than 0, and supplies the one-component developer and also peels off the developed developer (undeveloped developer) on the developer carrier.

When the electrostatic latent image on the photosensitive member is developed with a one-component developer on the developer bearing member in the developing area, a direct and / or alternating current is applied between the developer bearing member and the photosensitive drum. It is preferred to apply a developing bias of to develop.

Next, the non-contact jumping development method will be described.

The non-contact jumping development method includes a development method using a one-component developer having a magnetic toner or a non-magnetic toner.

Here, a developing method using a one-component non-magnetic developer having a non-magnetic toner will be described with reference to a schematic configuration diagram shown in FIG.

The developing device 170 includes a developing container 17 containing a non-magnetic one-component developer 176 having a non-magnetic toner.
1. A developer carrier 172 for carrying the one-component non-magnetic developer 176 contained in the developing container 171 and transporting it to the development area, and supplying the one-component non-magnetic developer on the developer carrier Roller 173 for controlling the thickness, the elastic blade 174 as a developer layer thickness regulating member for regulating the thickness of the developer layer on the developer carrier, and the one-component non-magnetic developer 176 in the developing container 171 are stirred. Stirring member 175 for the purpose.

Reference numeral 169 denotes an electrostatic latent image holding member, and the latent image is formed by electrophotographic processing means or electrostatic recording means (not shown). Reference numeral 172 denotes a developing sleeve as a developer carrier, which is made of a non-magnetic sleeve made of aluminum or stainless steel.

As the developing sleeve, a rough tube of aluminum or stainless steel may be used as it is, but preferably, the surface thereof is uniformly roughened by spraying glass beads,
A mirror-finished one or a resin-coated one is preferred.

The one-component non-magnetic developer 176 is used in the developing container 1
The developer is supplied to the developer carrier 172 by a supply roller 173. Supply roller 173
Is made of foam material such as polyurethane foam,
The developer carrier is rotated in a forward or reverse direction at a relative speed other than 0, and the developer is supplied and the developer (undeveloped developer) on the developer carrier 172 after the development is peeled off. ing. The one-component non-magnetic developer supplied onto the developer carrier 172 is uniformly and thinly applied by an elastic blade 174 as a developer layer thickness regulating member.

The contact pressure between the elastic coating blade and the developer carrier is 0.3 to 2 as a linear pressure in the developing sleeve genera direction.
5 kg / m, preferably 0.5 to 12 kg / m is effective. When the contact pressure is less than 0.3 kg / m, it is difficult to uniformly apply the one-component non-magnetic developer, and the charge amount distribution of the one-component non-magnetic developer becomes broad, which causes fogging and scattering. When the contact pressure exceeds 25 kg / m, a large pressure is applied to the one-component non-magnetic developer, and the one-component non-magnetic developer is deteriorated. Absent. Further, a large torque is required to drive the developer carrier, which is not preferable. That is, by adjusting the contact pressure to 0.3 to 25 kg / m, it becomes possible to effectively loosen the aggregation of the one-component non-magnetic developer using the toner of the present invention. It is possible to instantly raise the charge amount of the non-magnetic developer.

As the developer layer thickness regulating member, an elastic blade or an elastic roller can be used, and it is preferable to use a material of a triboelectric series suitable for charging the developer to a desired polarity.

In the present invention, silicone rubber, urethane rubber and styrene butadiene rubber are preferred. Furthermore, polyamide, polyimide, nylon, melamine, melamine cross-linked nylon, phenolic resin, fluororesin,
An organic resin layer such as a silicone resin, a polyester resin, a urethane resin, and a styrene resin may be provided. Uses conductive rubber and conductive resin, and further disperses fillers and charge control agents such as metal oxides, carbon black, inorganic whiskers, and inorganic fibers in the rubber and resin of the blade to achieve appropriate conductivity and charging. It is preferable because it can provide imparting properties and appropriately charge the one-component non-magnetic developer.

In this non-magnetic one-component developing method, in a system in which a one-component non-magnetic developer is thinly coated on a developing sleeve by a blade, a one-component non-magnetic developer on a developing sleeve is required to obtain a sufficient image density. It is preferable that the thickness of the non-magnetic developer layer is made smaller than the opposing gap length β between the developing sleeve and the latent image holding member, and an alternating electric field is applied to this gap.
That is, by applying a developing bias in which an alternating electric field or a DC electric field is superimposed on the alternating electric field between the developing sleeve 172 and the latent image holder 169 by the bias power supply 177 shown in FIG. The transfer of the one-component non-magnetic developer to the non-magnetic developer can be facilitated, and a higher quality image can be obtained.

The charging step using a contact charging member for primary charging the surface of the latent image holding member used in the above-described image forming method will be described in detail below.

In the present invention, in order to primary-charge the surface of the holding member by contact charging, the surface of the photosensitive member having the charge injection layer having a volume resistance of 10 ⁸ to 10 ¹⁵ Ωcm is compared with the rotating body of the conductor. When the volume resistance value in the dynamic resistance measurement method in contact with the substrate is | V−VD | / d or | V | / d
When the higher electric field is V1 (V / cm),
In the applied electric field range of 20 to V1 (V / cm), 1
The charging is performed by applying a voltage by bringing a contact charging member in a range of from 0 ⁴ Ωcm to ^{10 10} Ωcm into contact. Here, V is the applied voltage applied to the contact charging member, VD is the potential on the photoconductor when it enters the nip between the photoconductor and the contact charging member, d
Is the distance between the voltage applying portion of the contact charging member and the photosensitive member.

By employing the above-described structure using the charging member and the photosensitive member according to the present invention, the charging start voltage Vh is small and the photosensitive member charging potential is charged to almost 90% or more of the voltage applied to the charging member. Becomes possible. For example, when a DC voltage of 100 to 2000 V in absolute value is applied to the charging member, the charging potential of the electrophotographic photosensitive member having the charge injection layer can be set to 80% or more, and more preferably 90% or more of the applied voltage. On the other hand, the charging potential of the photoconductor obtained by charging using the conventional discharge is almost 0 V when the applied voltage is 640 V or less, and only about 640 V from the applied voltage is obtained when the applied voltage is 640 V or more. Did not.

The distance (d) between the voltage application portion of the contact charging member and the photoreceptor is preferably 300 μm to 800 μm, from the viewpoint that good charging properties can be obtained.

As described above, in the present invention, as a means for improving the charging efficiency of charge injection into the photosensitive member while using a medium-resistance contact charging member in order to prevent pinhole leak and adhesion of the charging member to the photosensitive member. It is preferable to provide a charge injection layer for assisting charge injection into the photoconductor on the surface of the photoconductor.

The charge injecting layer is made of a material having a medium resistance by dispersing an appropriate amount of light-transmitting and conductive particles in an insulating binder, and an ionic conductive material having a high light-transmitting property in an insulating binder. what constitutes by mixing or copolymerizing the resin with gender, or it is conceivable to constitute a resin alone with a photoconductive a medium resistance, the charge injection layer are all 10 ⁸ to 10 composed of these It is preferable to have a resistance of about ¹⁵ Ωcm.

By adopting the above-described structure, the charging by the charge injection, which would not otherwise occur unless the contact charging member had a resistance value of not more than 10 ³ Ωcm, and conversely 10 ⁴ Ωcm
It is possible to achieve both prevention of pinhole leak that could not be prevented otherwise.

According to the present invention, good chargeability due to charge injection which cannot be produced unless a low-resistance contact charging member is used in the past, and a pinhole on a photoreceptor which could not be prevented by a low-resistance contact charging member. In order to simultaneously satisfy the characteristic of leakage due to the above and to obtain sufficient potential convergence, the contact charging member that contacts the photoreceptor having the charge injection layer and charges by injection has the above resistance of 20 to V1 ( (V / cm), it is preferable to use a contact charging member in the range of 10 ⁴ Ωcm to ^{10 10} Ωcm.
The measurement was performed in an environment of 23 ° C./65%.

The resistance value of the charging member generally fluctuates depending on the applied electric field applied to the charging member. In particular, a high applied electric field has a low resistance, and a low applied electric field has a high resistance. Dependency is observed.

In the case where charging is performed by injecting electric charge into the photosensitive member, when the charged surface of the photosensitive member enters the nip portion between the photosensitive member and the charging member (upstream from the charging member). The voltage difference between the charging potential of the photosensitive member before the entry and the voltage applied to the charging member is large, and therefore, the electric field applied to the charging member increases. However, when the photoreceptor passes through the nip portion, charges are injected into the photoreceptor, and charging is gradually performed in the nip portion, so that the potential on the photoreceptor gradually decreases to an applied voltage applied to the charging member. Approach, the difference between the applied voltage applied to the voltage application portion and the potential on the photoreceptor is small, and the difference approaches the direction of 0 V,
Accordingly, the applied electric field applied to the charging member becomes smaller. That is, in the step of charging the photosensitive member, the applied electric field applied to the charging member is different between the upstream side and the downstream side of the nip portion of the charging member, and the applied electric field applied to the charging member is high on the upstream side and low on the downstream side. .

Therefore, if a charge removal step such as pre-exposure is performed before the charging step, the potential on the photosensitive member when it enters the nip portion of the charging member is almost 0 V, so that the upstream side is charged. The applied electric field is substantially determined by the applied voltage applied to the charging member. However, when a process for removing such charges is not provided, the applied voltage and polarity of charging and transfer, that is, on the photoreceptor after transfer, It is determined by the potential and the applied voltage applied to the charging member.

That is, when charging is performed by injecting charges onto the photosensitive member, even if the resistance value of the charging member is in the range of 10 ⁴ Ωcm to ^{10 10} Ωcm at a certain applied electric field. For example, an applied electric field of 0.3 × (| V | /) at an applied voltage of 30% of the applied voltage applied to the charging member
d) If the resistance exceeds 10 ¹⁰ Ωcm within the range of (V / cm) or less, the charging due to injection at the downstream side of the nip portion of the charging member is significantly reduced, and the applied voltage of 7
Charging up to 0% is good, but the remaining 30% has poor charge injectability, making it difficult to inject charges onto the photoreceptor, making it impossible to charge to a desired potential, resulting in poor charging. In other words, the resistance value when a lower electric field is applied has a great effect on the charge injectability to the photoconductor.

Therefore, the volume resistance value of the contact charging member in the dynamic resistance measuring method in which the charging member is brought into contact with the rotating body of the conductor is | V−VD | / d or | V | / d. When the higher electric field is V1 (V / cm), 20 to
10 ⁴ Ω in the applied electric field range of V1 (V / cm)
It is necessary to use a contact charging member in the range of ¹⁰ cm to 10 ¹⁰ Ωcm, and a potential substantially equal to the applied voltage can be obtained on the photosensitive member.

On the other hand, if the applied electric field at an applied voltage applied to the charging member is less than 10 ⁴ Ωcm, an excessive leakage current flows from the contact charging member to scratches, pinholes, etc. generated on the surface of the photoreceptor. As a result, poor charging in the surroundings, enlargement of pinholes, and destruction of electrification of the charging member occur.
Since the conductive layer (metal substrate) of the photoreceptor is exposed on the surface of the scratches and pinholes on the photoreceptor, the potential on the photoreceptor is 0 V. Therefore, the maximum applied electric field of the charging member is applied to the charging member. It is determined by the applied voltage applied.

That is, even if the resistance value of the charging member is controlled within the range of 10 ⁴ Ωcm to ^{10 10} Ωcm at a certain applied electric field, poor charging and poor pressure resistance will result.

Therefore, in order to charge the photosensitive member, the maximum electric field of the charging member, that is, the voltage applied between the photosensitive member potential upstream of the charging member nip and the voltage applied to the charging member is determined. The applied electric field V1 (V / cm), which is the higher of the electric field or the applied electric field determined by the applied voltage applied to the charging member when a pinhole is present due to a pre-exposure step or a scratch or the like on the photosensitive member. ), The resistance value must be in the range of 10 ⁴ Ω to ^{10 10} Ω in the applied electric field range of 20 to V1 (V / cm).

The larger the nip width between the charging member and the photosensitive member, the larger the contact area between the charging member and the photosensitive member and the longer the contact time. Good charging is achieved. However, in order to obtain a sufficient charge injection property even when the nip width is narrowed, the resistance of the charging member is set to R1 and R2 of the resistance due to the applied electric field within the range of the applied electric field. / R2 ≦ 1
It is preferably in the range of 000. In the process in which charging is performed in the nip, a sudden change in resistance causes the injection of charge to the photoconductor not to follow, passes through the nip, and may not be sufficiently charged. It is.

The voltage applied to the contact charging member is AC
In discharging, the effect of aligning the toner charge to the regular toner charging polarity is not sufficient, and in DC discharging, the toner charging aligns to the regular toner charging polarity, but the toner tends to be excessively charged and adversely affects development. On the contrary, in the present invention, the configuration using the photoreceptor and the contact charging member as described above adjusts the charge of the residual toner to the normal toner charge polarity and appropriately controls the charge amount. This makes it possible to provide an image forming method which is excellent in recoverability of toner remaining after transfer and has stable repetition characteristics of development.

In the present invention, it is preferable that the polarity of frictional charging of the contact charging member with the photoconductor is the same as the charging polarity of the photoconductor. According to the knowledge of the present inventors, the charging potential of the photoconductor in the charging step by charge injection is obtained by adding frictional charging of the contact charging member with the photoconductor to the injection property. If the frictional charging polarity of the contact charging member with the photoreceptor is opposite to the charging polarity of the photoreceptor, the potential of the photoreceptor is reduced by the amount of the triboelectric charge, thereby causing a potential difference between the contact charging member and the surface of the photoreceptor. The reduction of the photoreceptor potential due to frictional charging is almost up to several tens of volts. However, this electric field reduces the recoverability and retention of the transfer residual toner of the contact charging member. It causes transfer to the photoreceptor and causes image defects such as positive ghost and fog.

In the present invention, it is preferable that the contact charging member moves with a peripheral speed difference with respect to the photosensitive member. By making the moving speed of the peripheral surface of the contact charging member different from the moving speed of the surface of the photoreceptor, while maintaining the charging stability for a long period of time, maintaining the long life of the photoreceptor, and maintaining the long life of the charging roller Can be achieved at the same time, and high stabilization of charging and a long life of the image forming system can be achieved. That is, the toner easily adheres to the surface of the contact charging member, and the adhered toner tends to inhibit the charging. By making the surface moving speed of the photoconductor different from the surface moving speed of the contact charging member, the toner is attached to the same photoconductor surface. On the other hand, it is possible to supply substantially more contact charging member surfaces, so that an effect on charging inhibition is obtained. In other words, when the transfer residual toner comes to the charged portion, the toner having a small adhesive force to the photoconductor moves toward the charging member due to the electric field, and the resistance of the surface of the charging member locally changes, so that the discharge path is interrupted. As a result, it becomes difficult to apply a potential to the surface of the photoreceptor, and as a result, the problem of poor charging is effectively solved.

From the viewpoint of simultaneous cleaning with development,
Due to the peripheral speed difference between the contact charging member and the photoconductor, an effect of physically peeling off the toner adhesion portion from the surface of the photoconductor and improving the efficiency of collection by an electric field can be expected, and the transfer residual toner can be further improved. It is possible to control the charging efficiency and improve the recoverability in the development.

If a speed difference is provided between the surface of the photoconductor and the surface of the contact charging member, the contact angle of water with respect to the surface of the photoconductor is reduced in order to prevent abrasion or contamination of the surface of the photoconductor or the surface of the contact charging member due to mutual rubbing effect. Is 85 degrees or more, preferably 90 degrees
A photoreceptor of a degree or higher is effective.

When the photosensitive member surface moving speed and the contact charging member surface moving speed are made different from each other, preferably, when the photosensitive member surface moving speed is V and the roller surface moving speed is v at the contact portion between the photosensitive member and the roller, The absolute value of v / V is 1.
If it is 1 or more, that is, if it is 110% or more, stable characteristics in chargeability can be obtained, and improvement in recoverability of toner remaining after transfer in development can be seen.

The shape of the contact charging member may be a blade shape or a brush shape, but it is considered that a rotatable roller shape, a belt shape, or a brush roller shape is advantageous for appropriately setting the peripheral speed difference.

The roller-shaped contact charging member is disclosed as a material in, for example, Japanese Patent Application Laid-Open No. 1-211799, but as a conductive substrate, a metal such as iron, copper, stainless steel, a carbon-dispersed resin, a metal or And a metal oxide-dispersed resin can be used.

As the structure of the elastic roller, a structure in which an elastic layer, a conductive layer, and a resistance layer are provided on a conductive substrate is used.

As the elastic layer, rubber such as chloroprene rubber, isoprene rubber, EPDM rubber, polyurethane rubber, epoxy rubber, butyl rubber, sponge, styrene-butadiene thermoplastic elastomer, polyurethane thermoplastic elastomer, polyester thermoplastic elastomer, ethylene -It can be formed of a thermoplastic elastomer such as vinegar plastic thermoplastic elastomer.

The conductive layer has a volume resistivity of 10 ⁷ Ωc.
m, preferably 10 ⁶ Ωcm or less. For example,
A metal-deposited film, a conductive particle-dispersed resin, and a conductive resin are used. Specific examples include vapor-deposited films of aluminum, indium, nickel, copper, iron, and the like, and conductive particles such as carbon, aluminum, nickel, and titanium oxide as urethane, polyester, and vinyl acetate. Examples thereof include those dispersed in a resin such as a vinyl chloride copolymer polymethyl methacrylate. As the conductive resin, quaternary ammonium salt-containing polymethyl methacrylate,
Examples include polyvinyl aniline, polyvinyl pyrrole, polydiacetylene, and polyethylene imine.

The resistance layer has, for example, a volume resistivity of 10 ⁶ Ω.
cm 10 to 10 ¹² Ωcm, and a semiconductive resin, a conductive particle dispersed insulating resin, or the like can be used. Examples of the semiconductive resin include ethyl cellulose, nitrocellulose, methoxymethylated nylon, ethoxymethylated nylon, copolymerized nylon, polyvinylhydrin, and casein. Examples of the conductive particle-dispersed resin include a small amount of conductive particles such as carbon, aluminum, indium oxide, and titanium oxide in an insulating resin such as urethane, polyester, vinyl acetate-vinyl chloride copolymer, and polymethyl methacrylate. Dispersed materials may be mentioned.

One preferred embodiment of the present invention uses a rotatable brush roll as the contact charging member. When the contact portion with the photoreceptor is a fine fiber, the number of points of contact with the photoreceptor is significantly increased as compared with a roller having a smooth surface, which is advantageous in giving a uniform charging potential to the photoreceptor.

As a fiber aggregate preferably used for forming a brush, an aggregate composed of ultrafine fiber-generating conjugate fibers, an aggregate whose fibers are chemically treated with an acid, an alkali or an organic solvent, a brushed fiber Fiber entangled bodies and electrostatic flocking.

It is considered that the essential charging mechanism in the present invention is that charge is injected from the conductive charging layer to the charge injection layer when the conductive charging layer comes into contact with the charge injection layer on the surface of the photoreceptor. Therefore, the characteristics required for the charging member are to have a sufficient density on the surface of the charge injection layer and an appropriate resistance to the movement of charges.

Therefore, a method of increasing the fiber density by using ultrafine fiber-generating conjugate fibers, a method of increasing the number of fibers by chemical etching of the fibers, and a method of raising a fiber entangled member or an electrostatic flocking to the surface are used. The method of providing a flexible fiber end has the effect of increasing the frequency of contact with the charge injection layer, and enables uniform and sufficient charging. That is, a configuration in which the fiber density is increased, the number of contact points is increased, and the fiber end is in contact with the charge injection layer is suitably used in the present invention.

It is preferable that the aggregate composed of the ultrafine fiber-generating conjugate fiber generates ultrafine fibers physically or chemically, and the raised fiber entangled body is an ultrafine fiber-generating conjugate fiber. Preferably, the ultrafine fiber-generating conjugate fiber is physically or chemically generated to generate ultrafine fibers, and is more preferably raised.

It is preferable that the constituent fibers of the electrostatic flocking body have been chemically treated with an acid, an alkali or an organic solvent. Another preferred form of the electrostatic flocking is a form in which the constituent fibers are microfiber-generating conjugate fibers and physically or chemically generate microfibers.

One preferred embodiment of the present invention uses magnetic particles for the contact charging member. Further, the form of the conductive magnetic particles in which the volume resistivity of the magnetic particles is controlled in the resistance range of 10 ⁴ Ωcm to 10 ⁹ Ωcm is preferable.

The average particle size of the magnetic particles is preferably from 5 to 20 μm. If it is less than 5 μm, the magnetic brush tends to adhere to the photoreceptor, and if it is more than 200 μm, the density of the magnetic brush on the sleeve cannot be increased, and the chargeability to be injected into the photoreceptor deteriorates. There is a tendency. More preferably, the particle size is 10 to 100 μm, and within this particle size range, the residual toner on the photoreceptor is more efficiently scraped, more efficiently electrostatically taken into the magnetic brush, and more reliably. In order to control the charging of the toner, the toner can be temporarily held in the magnetic brush. Further, the average particle size of the magnetic particles is more preferably from 10 to 50 μm.

The average particle diameter of the whole was randomly extracted by using an optical microscope or a scanning electron microscope.
The volume particle size distribution is calculated using the maximum chord length in the horizontal direction, and the 50% average particle size may be used as the average particle size. Alternatively, using a laser diffraction particle size distribution analyzer HEROS (manufactured by JEOL Ltd.) Range of ~ 200 μm
The measurement may be performed by dividing by two logarithms, and the average particle size may be defined as the 50% average particle size.

When magnetic particles having these particle sizes are used for the contact charging member, the number of points of contact with the photoreceptor greatly increases,
This is advantageous in giving a uniform charging potential to the photoconductor. Further, there is an advantage that the magnetic particles that are in direct contact with the photoreceptor can be replaced by the rotation of the magnetic brush, so that a decrease in charge injection property due to contamination of the magnetic particle surface can be significantly reduced.

The gap between the holding member for holding the magnetic particles and the photosensitive member is preferably in the range of 0.2 to 2 mm. If the diameter is smaller than 0.2 mm, the magnetic particles are less likely to pass through the gap, and the magnetic particles are not smoothly transported on the holding member, resulting in poor charging and excessive accumulation of the magnetic particles in the nip portion, causing adhesion to the photoreceptor. If the diameter is larger than 2 mm, it is difficult to form a wide nip width between the photosensitive member and the magnetic particles, which is not preferable. More preferably, it is 0.2 to 1 mm, particularly preferably 0.3 to 0.7 mm.

In the present invention, the contact charging member has a magnet for holding magnetic particles, and the magnetic flux density B (T: Tesla) of the magnetic field generated by the magnet and the magnetic flux density within the magnetic flux density B It is preferable that the maximum magnetization σ _{B of the} particles is set to each value that satisfies the following relational expression.

B · σ _B ≧ 4 If the above expression is not satisfied, the coercive force of the contact charging member on the magnetic particles is not sufficient because the magnetic force acting on the magnetic particles is small, and the magnetic particles are transferred to the photoreceptor. May be lost.

The magnetic particles according to the present invention are made of magnetic material such as iron, cobalt, nickel, etc., which are made of magnetic material, such as iron, cobalt, nickel, etc. An alloy or a compound containing, for example, a ferrite whose composition is adjusted by performing an oxidation treatment, a reduction treatment, or the like, and a Zn—Cu ferrite subjected to a hydrogen reduction treatment are used. Adjustment of the composition of the metal can also be used to keep the ferrite resistance within the above-mentioned range below the applied electric field as described above. In general, the resistance increases when the amount of metal other than divalent iron increases. And the resistance tends to drop sharply.

It is preferable that the triboelectric charging polarity of the magnetic particles used in the present invention is not opposite to the charging polarity of the photoreceptor.
As described above, the decrease in the charging potential of the photoconductor due to the triboelectric charge is a force in the direction of the transfer of the magnetic particles to the photoconductor, so that the conditions for holding the magnetic particles on the contact charging member are more severe.
As a method of controlling the triboelectric charging property of the magnetic particles, it is easy to use a magnetic particle surface coating.

The form of the magnetic particles having a surface layer used in the present invention is such that the surface of the magnetic particles is coated with a vapor-deposited film, a conductive resin film, a conductive pigment-dispersed resin film, or the like.
The surface layer does not necessarily need to completely cover the magnetic particles, and the magnetic particles may be exposed as long as the effects of the present invention can be obtained. That is, the surface layer may be formed discontinuously.

It is preferable to coat a conductive pigment-dispersed resin film from the viewpoint of productivity, cost and the like.

Further, from the viewpoint of suppressing the electric field dependence of the resistance value, it is preferable to coat a high-resistance binder resin with a resin film in which an electron-conductive conductive pigment is dispersed.

As a matter of course, the resistance of the magnetic particles after coating must be within the above-mentioned range, and furthermore, the resistance drops sharply on the high electric field side, and depends on the size and depth of the scratch on the photoreceptor. From the viewpoint of widening the allowable range of the leak image generation, it is preferable that the resistance of the base magnetic particles also falls within the above range.

Examples of the binder resin used for coating the magnetic particles include styrenes such as styrene and chlorostyrene; monoolefins such as ethylene, propylene, butylene and isobutylene; vinyl acetate, vinyl propionate, vinyl benzoate and butyric acid. Vinyl esters such as vinyl; α-methylenes such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Aliphatic monocarboxylic acid esters; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone alone Polymer or copolymer. Particularly typical binder resins include polystyrene, styrene-alkyl acrylate copolymer (styrene-acrylonitrile copolymer, Styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyethylene, polypropylene, polycarbonate, phenolic resin, polyester,
Examples include polyurethane, epoxy resin, polyolefin, fluorine resin, silicone resin, and polyamide. In particular, from the viewpoint of preventing toner contamination, it is more desirable to include a resin having a low critical surface tension, for example, a polyolefin, a fluororesin, or a silicone resin.

Further, from the viewpoint of maintaining a wide allowable range for preventing a leak image due to a reduction in resistance on the high electric field side and a scratch on the photosensitive member,
The resin coated on the magnetic particles is preferably a high voltage resistant silicone resin or the like.

As the fluororesin, for example, polyvinyl fluoride, polyvinylidene fluoride, polytrifluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, polytetrafluoroethylene, polyhexafluoropropylene and other monomers are copolymerized. And a solvent-soluble copolymer.

Examples of the silicone resin include KR271, KR282, KR311 and KR manufactured by Shin-Etsu Silicone Co., Ltd.
255, KR155 (straight silicone varnish),
KR211, KR212, KR216, KR213, K
R217, KR9218 (modified silicone varnish),
SA-4, KR206, KR5206 (silicone alkyd varnish), ES1001, ES1001N, ES
1002T, ES1004 (silicone epoxy varnish), KR9706 (silicone acrylic varnish), K
R5203, KR5221 (silicone polyester varnish) and SR2100, SR21 manufactured by Toray Silicone Co., Ltd.
01, SR2107, SR2110, SR2108, S
R2109, SR2400, SR2410, SR241
1, SH805, SH806A, and SH840 are used.

The dynamic resistance of the magnetic particles was measured using an apparatus as shown in FIG. That is, a magnet-encapsulating sleeve 91 as a magnetic particle holding member having an aluminum drum 92 as a conductive base and a gap 94 of 0.5 mm.
The nip 93 between the magnetic particles 97 and the aluminum drum is 5 m
m, rotate the charging member and photoconductor at the rotation speed and rotation direction when actually forming an image, apply a DC voltage to the charging member, and measure the current flowing through the system. And the nip 93
The dynamic resistance was calculated from the width of contact between the magnetic particles and the aluminum drum.

In the present invention, the charge injection layer of the photoreceptor is composed of an inorganic layer such as a metal vapor-deposited film, or a conductive powder resin dispersion layer in which conductive fine particles are dispersed in a binder resin. The conductive powder resin dispersion film is formed by applying a suitable coating method such as a dipping coating method, a spray coating method, a roll coating method, and a beam coating method. It may be constituted by mixing or copolymerizing a resin having high light transmittance and ionic conductivity with an insulating binder, or may be constituted by a single resin having a medium resistance and photoconductivity. In the case of the conductive fine particle dispersed film, the amount of the conductive fine particles is 2 to 250 parts by weight based on 100 parts by weight of the binder resin.
It is preferable that the amount be 2 parts by weight, more preferably 2 to 190 parts by weight. If the amount is less than 2 parts by weight, it is difficult to obtain a desired volume resistance value. If the amount is more than 250 parts by weight, the film strength is reduced and the charge injection layer is easily scraped off. This is because the resistance tends to be short, and the resistance becomes low, so that an image defect easily occurs due to the flow of the latent image potential.

The binder of the charge injection layer may be the same as the binder of the lower layer. However, in this case, the coating surface of the charge transport layer may be disturbed at the time of coating the charge injection layer. In particular, it is necessary to select a coating method.

In the present invention, the charge injection layer preferably contains lubricant particles. The reason is that the friction between the photoreceptor and the injection charging member during charging is reduced, so that the charging nip is enlarged and the charging characteristics are improved. In particular, it is more preferable to use a fluororesin, a silicone resin, or a polyolefin resin having a low critical surface tension as the lubricant particles. More preferably, ethylene tetrafluoride resin (PTFE)
Is used. In this case, the addition amount of the lubricant particles is preferably 2 to 50 parts by weight, and more preferably 5 to 40 parts by weight based on 100 parts by weight of the binder. If the amount is less than 2 parts by weight, the amount of the lubricant powder is not sufficient, so that the charging characteristics are not sufficiently improved. If the amount exceeds 50 parts by weight, the resolution of the image and the sensitivity of the photoreceptor are greatly reduced. Because.

In the present invention, the thickness of the charge injection layer is 0.1
It is preferably from 10 to 10 μm, particularly preferably from 1 to 7 μm.

The present invention relates to a medium-resistance contact charging member for injecting electric charge to the surface of a photoreceptor having a medium-resistance surface resistance. Preferably, the electric charge is injected to a trap potential of the surface material of the photoreceptor. Instead, the electric charge is charged by charging the conductive fine particles of the charge injection layer in which the conductive fine particles are dispersed in a light-transmitting and insulating binder.

More specifically, it is based on the theory of charging a small capacitor having a charge transporting layer as a dielectric material and an aluminum substrate and conductive fine particles in the charge injection layer as both electrode plates with a contact charging member. is there. At this time, the conductive fine particles are electrically independent of each other and form a kind of minute float electrode. Therefore, macroscopically, the photoreceptor surface appears to be charged and charged to a uniform potential, but in reality, there are situations in which countless minute charged charged conductive fine particles cover the photoreceptor surface. Has become. Therefore, even if image exposure is performed by a laser, each conductive fine particle is electrically independent, so that an electrostatic latent image can be held.

Accordingly, by substituting the trap level, which was present on the surface of the conventional photoreceptor, albeit little, with the conductive fine particles, the charge injection property and the charge retention property are improved.

Here, the method of measuring the volume resistance of the charge injection layer is as follows. A charge injection layer is formed on a polyethylene terephthalate (PET) film having a conductive film deposited on the surface thereof, and this is used as a volume resistance measurement device (Hewlett Packard Co., Ltd.). Made 41
The measurement is performed by applying a voltage of 100 V in an environment of 23 ° C. and 65% at 40 B pAMATER).

[0287]

EXAMPLE 1 0.1 M Na ₃ PO ₄ was added to 700 parts by weight of ion-exchanged water.
An aqueous solution (450 parts by weight) was charged and heated to 50 ° C.
10, using a K-type homomixer (manufactured by Tokushu Kika Kogyo)
The mixture was stirred at 000 rpm. 1.0M-CaCl
₂ 70 parts by weight of the aqueous solution was gradually added to obtain an aqueous medium containing a calcium phosphate salt.

(Monomer) 170 parts by weight of styrene 30 parts by weight of n-butyl acrylate (colorant) I. Pigment Blue 15: 3 10 parts by weight (charge control agent) Metal compound of dialkylsalicylic acid 2 parts by weight (polar resin) Saturated polyester 20 parts by weight (acid value 10, peak molecular weight: 15,000) (release agent) behenyl stearate 30 parts by weight (DSC maximum endothermic peak: 68 ° C) (Crosslinking agent) 0.2 parts by weight of divinylbenzene (low molecular weight substance) 6 parts by weight of low molecular weight polystyrene (weight average molecular weight (Mw) 2,800, molecular weight distribution (Mw / Mn) 5.2) The above formulation was heated to 50 ° C, and uniformly dissolved and dispersed at 9,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). Into this, 1 part by weight of a polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was charged into the aqueous medium, and the mixture was stirred at 9500 rpm with a TK homomixer at 55 ° C. in an N ₂ atmosphere to granulate the polymerizable monomer composition. did.

Then, while stirring with a paddle stirring blade, 55
C. for 1 hour, and then the temperature was raised to 60 ° C. in 1 hour. After 4 hours of reaction, the temperature was raised at a rate of 40 ° C./Hr. At 80 ° C. for 4 hours. Nitrogen is bubbled every hour into the aqueous medium during the polymerization reaction, so that the dissolved oxygen concentration in the aqueous medium becomes 0.5%.
It was adjusted to be ~ 1.0 mg / l. After completion of the polymerization reaction, the remaining monomer was distilled off under reduced pressure, and after cooling, hydrochloric acid was added to dissolve the calcium phosphate salt, followed by filtration, washing with water and drying to obtain cyan colored particles having a weight average particle size of 7.0 μm ( Cyan toner particles) were obtained.

To 100 parts by weight of the obtained cyan toner particles, hydrophobic silica having a specific surface area of 200 m ² / g by a BET method was externally added to obtain a cyan toner A. 95 parts by weight of an acryl-coated ferrite carrier was mixed with 5 parts by weight of the obtained cyan toner A to prepare a two-component developer. Using this two-component developer, a fixing test and an endurance evaluation were performed using the following evaluator A. Tables 1 and 2 show the physical properties of the toner and the evaluation results.

Example 2 The durability of the cyan toner A obtained in Example 1 was evaluated by the following evaluator B. The results are shown in Tables 1 and 2.

Comparative Example 1 In Example 1, the polymerization initiator 2,2'-azobis (2,4-
A cyan toner B and a two-component developer were obtained in the same manner as in Example 1 except that 3 parts by weight of dimethylvaleronitrile) was added, and a fixing test and an endurance evaluation were performed using the following evaluator A. Tables 1 and 2 show the physical properties of the toner and the evaluation results.

Comparative Example 2 The durability of the cyan toner B obtained in Comparative Example 1 was evaluated by the following evaluator B. The results are shown in Tables 1 and 2.

Comparative Example 3 In Example 1, the polymerization initiator 2,2'-azobis (2,4-
Dimethyl valeronitrile) was added, and a cyan toner C and a two-component developer were obtained in the same manner as in Example 1 except that low-molecular-weight polystyrene as a low-molecular-weight substance was not added. And a fixing test and durability evaluation were performed. Tables 1 and 2 show the physical properties of the toner and the evaluation results.

Comparative Example 4 The durability of the cyan toner C obtained in Comparative Example 3 was evaluated by the following evaluator B. The results are shown in Tables 1 and 2.

Comparative Example 5 A cyan toner D and a two-component developer were obtained in the same manner as in Example 1 except that low-molecular-weight polystyrene as a low-molecular-weight substance was not added. To perform a fixing test and an endurance evaluation. Tables 1 and 2 show the physical properties of the toner and the evaluation results.

Comparative Example 6 The durability of the cyan toner D obtained in Comparative Example 5 was evaluated by the following evaluator B. The results are shown in Tables 1 and 2.

Comparative Example 7 A cyan toner E and a two-component developer were obtained in the same manner as in Example 1 except that 15 parts by weight of low-molecular-weight polystyrene, which is a low-molecular-weight substance, was used. And a fixing test and durability evaluation were performed. Tables 1 and 2 show the physical properties of the toner and the evaluation results.

Comparative Example 8 The durability of the cyan toner E obtained in Comparative Example 7 was evaluated by the following evaluator B. The results are shown in Tables 1 and 2.

Comparative Example 9 In Example 1, the amount 3 of the polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) was changed to parts by weight, and low-molecular-weight polystyrene as a low-molecular-weight substance was not added. A polymerizable monomer composition was prepared.

The temperature of the aqueous medium at the time of granulation of the polymerizable monomer composition was changed to 60 ° C., and after granulation, the temperature was raised to 80 ° C. in 1 hour while stirring with a paddle stirring blade, and then 10 hours. The cyan toner F and the two-component developer were prepared in the same manner as in Example 1 except that the polymerization conditions were changed so as to cause the reaction, and that nitrogen was not bubbled into the aqueous medium during the polymerization reaction. Then, a fixing test and an endurance evaluation were performed using the following evaluator A. Tables 1 and 2 show the physical properties of the toner and the evaluation results. Incidentally, the dissolved oxygen concentration in the aqueous medium during the polymerization reaction is:
1.5 mg / l.

Comparative Example 10 The durability of the cyan toner F obtained in Comparative Example 9 was evaluated by the following evaluator B. The results are shown in Tables 1 and 2.

Comparative Example 11 (Monomer) Styrene 170 parts by weight Ethylhexyl acrylate 30 parts by weight (colorant) I. Pigment Blue 15: 3 10 parts by weight (Charge control agent) Metal compound of dialkylsalicylic acid 2 parts by weight (mold release agent) Paraffin wax 30 parts by weight (DSC maximum endothermic peak: 70 ° C) (polymerization initiator) 2,2'- Azobis (2,4-dimethylvaleronitrile) 10 parts by weight Dimethyl 2,2'-azobisisobutyrate 1 part by weight

The above formulation was heated to 60 ° C. and uniformly dissolved and dispersed at 9,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare a polymerizable monomer composition.

The above polymerizable monomer composition was used in place of the polymerizable monomer composition used in Example 1, the temperature of the aqueous medium during granulation was changed to 60 ° C., and the After granulation, the mixture was reacted at 60 ° C. for 7 hours while stirring with a paddle stirring blade.
Example 1 was repeated except that the polymerization conditions were changed so that the temperature was raised to 80 ° C. for 4 hours and the reaction was carried out for 4 hours, and that nitrogen was not bubbled into the aqueous medium during the polymerization reaction.
To obtain a cyan toner G and a two-component developer,
A fixing test and an endurance evaluation were performed using the following evaluator A.
Tables 1 and 2 show the physical properties of the toner and the evaluation results. The concentration of dissolved oxygen in the aqueous medium during the polymerization reaction was 5 mg / l.

Comparative Example 12 The cyan toner G obtained in Comparative Example 11 was evaluated using the following evaluator B
The durability was evaluated. The results are shown in Tables 1 and 2.

Example 3 0.1M-Na ₃ PO ₄ was added to 800 parts by weight of ion-exchanged water.
500 parts by weight of an aqueous solution is added, and after heating to 50 ° C., T
10, using a K-type homomixer (manufactured by Tokushu Kika Kogyo)
The mixture was stirred at 000 rpm. 1.0M-CaCl
₂ 70 parts by weight of the aqueous solution was gradually added to obtain an aqueous medium containing a calcium phosphate salt.

(Monomer) Styrene 185 parts by weight n-butyl acrylate 15 parts by weight (colorant) I. Pigment Yellow 17 15 parts by weight (charge control agent) Metal compound of dialkyl salicylic acid 2 parts by weight (polar resin) Saturated polyester 15 parts by weight (acid value 15, peak molecular weight: 20,000) (release agent) Ester wax (DSC maximum) Endothermic peak: 70 ° C.) 30 parts by weight (crosslinking agent) 0.5 parts by weight of divinylbenzene (low molecular weight substance) 6 parts by weight of low molecular weight polystyrene (weight average molecular weight (Mw) 3,500, molecular weight distribution (Mw / Mn) 4 .5) The above formulation was heated to 50 ° C, and was uniformly dissolved and dispersed at 9,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). Into this, 1 part by weight of a polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was charged into the aqueous medium, and the mixture was stirred at 55 ° C. in a N ₂ atmosphere with a TK homomixer at 9,500 rpm to granulate the polymerizable monomer composition. did.

Thereafter, the mixture was stirred at 55 ° C. with a paddle stirring blade.
After 1 hour, the temperature was raised to 60 ° C. in 1 hour, and after 4 hours,
Heating rate 40 ° C / Hr. At 80 ° C. for 4 hours. Nitrogen is bubbled into the aqueous medium during the polymerization reaction every hour so that the dissolved oxygen concentration in the aqueous medium is 0.5 to 1.
It was adjusted to be 0 mg / l. After the completion of the polymerization reaction, the remaining monomer was distilled off under reduced pressure, and after cooling, hydrochloric acid was added to dissolve the calcium phosphate salt, followed by filtration, washing with water, and drying to obtain yellow colored particles having a weight average particle size of 7.2 μm ( (Yellow toner).

To 100 parts by weight of the obtained yellow colored particles, hydrophobic silica having a specific surface area of 200 m ² / g by the BET method was externally added to obtain a yellow toner H. 95 parts by weight of an acryl-coated ferrite carrier was mixed with 5 parts by weight of the obtained yellow toner H to obtain a two-component developer. Using this two-component developer, a fixing test and an endurance evaluation were performed using the following evaluator A. Tables 1 and 2 show the physical properties of the toner and the evaluation results.

Example 4 The yellow toner H obtained in Example 3 was evaluated using the following evaluator B
The durability was evaluated. The results are shown in Tables 1 and 2.

Comparative Example 13 A yellow toner I and a two-component developer were obtained in the same manner as in Example 3 except that 90 parts by weight of an ester wax as a release agent was added. And a fixing test and durability evaluation were performed. Tables 1 and 2 show the physical properties of the toner and the evaluation results.

Comparative Example 14 The yellow toner I obtained in Comparative Example 13 was evaluated for durability by the following evaluator B. The results are shown in Tables 1 and 2.

Comparative Example 15 A yellow toner J and a two-component developer were obtained in the same manner as in Example 3 except that the ester wax as a releasing agent was not added. A fixing test and durability evaluation were performed. Tables 1 and 2 show the physical properties of the toner and the evaluation results.

Comparative Example 16 The durability of the yellow toner J obtained in Comparative Example 15 was evaluated by an evaluation machine B. The results are shown in Tables 1 and 2.

Example 5 In 700 parts by weight of ion-exchanged water, 0.1 M Na ₃ PO _{4 was} added.
An aqueous solution (450 parts by weight) was charged and heated to 50 ° C.
10, using a K-type homomixer (manufactured by Tokushu Kika Kogyo)
The mixture was stirred at 000 rpm. 1.0M-CaCl
₂ 70 parts by weight of the aqueous solution was gradually added to obtain an aqueous medium containing a calcium phosphate salt.

(Monomer) 170 parts by weight of styrene 30 parts by weight of n-butyl acrylate (colorant) I. Pigment Blue 15: 3 10 parts by weight (charge control agent) Metal compound of dialkylsalicylic acid 2 parts by weight (polar resin) Saturated polyester 20 parts by weight (acid value 10, peak molecular weight: 15,000) (release agent) behenyl stearate 30 parts by weight (DSC maximum endothermic peak: 68 ° C) (Crosslinking agent) 0.2 parts by weight of divinylbenzene (low molecular weight substance) 6 parts by weight of low molecular weight polystyrene (weight average molecular weight (Mw) 2,800, molecular weight distribution (Mw / Mn) 5.2) The above formulation was heated to 50 ° C, and uniformly dissolved and dispersed at 9,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). Into this, 4 parts by weight of a polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was charged into the aqueous medium, and stirred at 9500 rpm with a TK homomixer at 55 ° C. in an N ₂ atmosphere to granulate the polymerizable monomer composition. did.

Thereafter, while stirring with a paddle stirring blade, 55
After 1 hour of reaction at 1 ° C., the temperature was raised to 60 ° C. in 1 hour, and after 4 hours, the temperature was raised at a rate of 5 ° C./Hr. At 80 ° C. for 4 hours. Nitrogen is bubbled into the aqueous medium during the polymerization reaction every hour so that the dissolved oxygen concentration in the aqueous medium is 0.5 to
It was adjusted to be 1.0 mg / l. After completion of the polymerization reaction, the remaining monomer was distilled off under reduced pressure, and after cooling, hydrochloric acid was added to dissolve the calcium phosphate salt, followed by filtration, washing with water and drying to obtain cyan colored particles having a weight average particle size of 7.0 μm ( Cyan toner) was obtained.

To 100 parts by weight of the obtained cyan colored particles, hydrophobic silica having a specific surface area of 200 m ² / g by a BET method was externally added to obtain a cyan toner K. 95 parts by weight of an acryl-coated ferrite carrier were mixed with 5 parts by weight of the obtained cyan toner K to obtain a two-component developer. Using this two-component developer, a fixing test and an endurance evaluation were performed using the following evaluator A. Tables 1 and 2 show the physical properties of the toner and the evaluation results.

Example 6 A four-necked flask was charged with 180 parts by weight of water purged with nitrogen and 20 parts by weight of a 0.2 wt% aqueous solution of polyvinyl alcohol, and then 77 parts by weight of styrene and acrylic acid-n-
23 parts by weight of butyl, 3 parts by weight of benzoyl peroxide and 0.01 part by weight of divinylbenzene were added, and stirred to form a suspension. Then, after the inside of the flask was replaced with nitrogen, the temperature was raised to 80 ° C. and maintained at the same temperature for 10 hours to carry out a polymerization reaction.

After the polymer was washed with water, it was dried under reduced pressure while maintaining the temperature at 65 ° C. to obtain a resin. 88 parts by weight of the resin, 2 parts by weight of a metal-containing azo dye, 5 parts by weight of carbon black, 8 parts by weight of paraffin wax, low molecular weight polystyrene (weight average molecular weight (Mw) 2,800, molecular weight distribution (Mw / Mn) 5.2 ) 2 parts by weight were mixed by a fixed-tank type dry mixer, and the mixture was melt-kneaded by a twin-screw extruder while the vent port was connected to a suction pump for suction.

This melt-kneaded product was coarsely ground with a hammer mill to obtain a coarsely crushed toner composition of 1 mm mesh pass.
Further, the coarsely crushed product is crushed by a mechanical crusher to a volume average diameter of 20 to 30 μm, and then crushed by a jet mill utilizing collision between particles in a swirling flow. The toner composition was modified by mechanical and mechanical shearing force and classified by a multi-stage classifier to obtain black toner particles having a weight average particle size of 6.9 μm.

To 98.6 parts by weight of the black toner particles, 1.4 parts by weight of colloidal silica were added and mixed to obtain a black ground toner L. 95 parts by weight of an acryl-coated ferrite carrier were mixed with 5 parts by weight of the black toner L to prepare a two-component developer. Using this two-component developer, a fixing test and an endurance evaluation were performed by the following evaluator A. Tables 1 and 2 show the physical properties of the toner and the evaluation results.

Example 7 A four-necked flask was charged with 180 parts by weight of nitrogen-purged water and 20 parts by weight of a 0.2 wt% aqueous solution of polyvinyl alcohol, and then 77 parts by weight of styrene and acrylic acid-n-
23 parts by weight of butyl, 1.5 parts by weight of 2,2'-azobis (2,4-dimethylvaleronitrile) and 0.01 part by weight of divinylbenzene were added, and stirred to form a suspension. After this,
After the atmosphere in the flask was replaced with nitrogen, the temperature was raised to 70 ° C. and maintained at the same temperature for 10 hours to carry out a polymerization reaction.

After the polymer was washed with water, it was dried under reduced pressure while maintaining the temperature at 65 ° C. to obtain a resin. 88 parts by weight of the resin, 2 parts by weight of salicylic acid metal compound, 5 parts by weight of quinacridone, 9 parts by weight of paraffin wax, low molecular weight polystyrene (weight average molecular weight (Mw) 3,500, molecular weight distribution (Mw / Mn) 4.5) 1 The parts by weight were mixed by a fixed-tank type dry mixer, and the mixture was melt-kneaded by a twin-screw extruder while the vent port was connected to a suction pump for suction.

The melt-kneaded product was coarsely ground with a hammer mill to obtain a coarsely crushed toner composition of 1 mm mesh pass.
Further, the coarsely crushed product is crushed by a mechanical crusher to a volume average diameter of 20 to 30 μm, and then crushed by a jet mill utilizing collision between particles in a swirling flow. The toner composition was modified by mechanical and mechanical shearing force, and classified by a multi-stage classifier to obtain magenta toner particles having a weight average particle size of 7.5 μm.

To 98.6 parts by weight of the magenta toner particles, 1.4 parts by weight of colloidal silica were added and mixed to obtain a magenta ground toner M. Acrylic-coated ferrite carrier 9 was added to 5 parts by weight of the magenta toner M.
5 parts by weight were mixed to obtain a two-component developer. Using this two-component developer, a fixing test and an endurance evaluation were performed by the following evaluator A. Tables 1 and 2 show the physical properties of the toner and the evaluation results.

(Evaluation Method) Evaluator A Recording was performed using a commercially available full-color copying machine CLC-500 (manufactured by Canon Inc.) using a remodeling machine in which a non-magnetic one-component type developer can be used and a peripheral process. An unfixed image was formed on the material.

An unfixed image formed on a recording material is fixed
A fixing unit of a commercially available NP-6650 (manufactured by Canon Inc.) was set to a fixing speed of 150 mm / sec, and the fixing temperature was set to 5 ° C.
The one modified so as to be able to modulate every other time (120 ° C. to 220 ° C.) was used. As a recording material, commercially available copy paper Canon New Dry Paper (available from a Canon sales company, basis weight: 54 g / m ² ) was used.

Evaluation Machine B Using a modified machine in which a commercially available copying machine NP-6030 (manufactured by Canon Inc.) was changed to a developing machine for developing using a non-magnetic one-component developing material as shown in FIG. An unfixed image was formed thereon.

The fixing of the unfixed image formed on the recording material
A fixing unit of a commercially available NP-6650 (manufactured by Canon Inc.) was set to a fixing speed of 150 mm / sec, and the fixing temperature was set to 5 ° C.
The one modified so as to be able to modulate every other time (120 ° C. to 220 ° C.) was used. As a recording material, commercially available copy paper Canon New Dry Paper (available from a Canon sales company, basis weight: 54 g / m ² ) was used.

In FIG. 5, reference numeral 52 denotes a photosensitive drum as a latent image holding member; 55, a corona charger for primary charging the surface of the photosensitive drum 52;
Is an exposure for forming an electrostatic latent image on the surface of the primary charged photoconductor drum 52; and 51 is a non-magnetic toner having a toner for developing the electrostatic latent image formed on the photoconductor 52. Reference numeral 54 denotes a recording material as a transfer material for transferring a toner image;
Is a corona transfer unit for transferring the toner image of the photoconductor 52 to the recording material 54. As the developing device 52, FIG.
The development was performed under the following development conditions using the developing apparatus shown in FIG.

Developing conditions Developing sleeve: Stainless steel sleeve blasted with ^# 600 glass beads Gap between developing sleeve and photosensitive drum β: 500 μm Elastic blade: Urethane rubber plate with nylon resin layer on the surface Developing on developing sleeve Agent layer thickness: 70 μm Development bias: AC electric field with peak voltage of 2 KV Process speed: 150 m / sec

The following evaluation items were evaluated using the evaluation machines A and B described above.

[0338] (Evaluation Items) fog fog, the fog amount of reflection densitometer (TOKYO DE
NSHOKU CO. , LTD REFLECTO
METER ODEL TC-6DS) (Ds-Dr when Ds is the worst value of the reflection density on a white background after printing, and Ds is the average reflection density of the paper before printing is Dr)
Was determined as the fog amount). When the fog amount is 2% or less, a good image having substantially no fog is obtained, and when the fog amount exceeds 5%, the image is fuzzy and unclear.

The evaluation criteria for each of the evaluator A and the evaluator B are shown below.

(Evaluation Criteria of Evaluation Machine A) a: Fog amount less than 2% at the end of printing 20,000 sheets b: Fog amount 2% or more at the end of printing 20,000 sheets c: 15,000 sheets at the end of printing Fog amount 2% or more d: fog amount 2% or more at the end of printing 10,000 sheets e: fog amount 2% or more at the end of 5,000 sheets printing

(Evaluation Criteria of Evaluation Machine B) a: Fog amount less than 2% at the end of printing 3,000 sheets b: Fog amount 2% or more at the end of printing 3,000 sheets c: At the end of printing 1,000 sheets Fog amount 2% or more d: fog amount 2% or more at the end of printing 500 sheets e: fog amount 2% or more at the end of 100 sheets printing

[0342] Visually carrier, sleeve, the toner contamination of the photoconductor for toner fusion toner fusion were evaluated the degree of toner fusing on the basis of the following evaluation criteria.

(Evaluation Criteria of Evaluation Machine A) a: No toner fusion occurred at the end of printing 20,000 sheets b: Toner fusion occurred at the end of printing 20,000 sheets c: At the end of printing 15,000 sheets , Toner fusion occurred d: toner fusion occurred at the end of 10,000-sheet printing e: toner fusion occurred at the end of 5,000-sheet printing (evaluation criteria of evaluation machine B) a: at the end of 3,000-sheet printing B: no toner fusion occurred. B: toner fusion occurred at the end of printing 3,000 sheets. C: toner fusion occurred at the end of printing 1,000 sheets. D: toner fusion occurred at the end of printing 500 sheets. E: 100 At the end of sheet printing, toner fusion occurs

The charge amount of the toner was measured by the following method.

In the evaluation machine A, at the start of the endurance and at the end of the endurance, the toner containing the carrier was taken out of the modified CLC-500, and the following measuring apparatus and the following measuring method were used.
The charge amount of the toner was measured using a calculation method.

In the evaluator B, under normal temperature and normal humidity conditions,
After the toner and the carrier were allowed to stand overnight, the charge amount of the toner was measured using the following measurement setup, the following measurement method, and the calculation method.

FIG. 6 is an explanatory view of an apparatus for measuring the triboelectric charge amount of the toner. First, a mixture of toner and carrier whose weight ratio is to be measured at a weight ratio of 1:19 is 50 to
Put into a 100 ml polyethylene bottle and infiltrate by hand for 5 to 10 minutes.
About 0.5 to 1.5 g of the mixture (developer) is put into a metallic measuring container 202 having a metallic cover 204.
At this time, the weight of the entire measurement container 202 is weighed and W ₁ (g)
And Next, in the suction device 201 (at least the portion in contact with the measurement container 202 is an insulator), the pressure of the vacuum gauge 205 is adjusted to 250 mmAq by adjusting the air volume control valve 206 by suctioning from the suction port 207. In this state, suction is sufficiently performed, preferably for 2 minutes, to remove the toner by suction. The potential of the electrometer 209 at this time is set to V (volt). Where 20
Reference numeral 8 denotes a capacitor having a capacity of C (μF). The weight of the whole measuring container of the suction machine is weighed and is defined as W ₂ (g). The triboelectric charge (mC / kg) of this toner is calculated as in the following equation.

[0348]

[Outside 2]

Image Density Image density (5 mm square, 500 mm round, solid) was measured with a Macbeth densitometer (manufactured by Macbeth).

Fixing Start Density The fixing start temperature is determined by modulating the fixing temperature from 120 ° C. to 5 ° C., fixing the image, and observing the obtained fixed image on symbol paper 10 times with a load of about 100 g. Image peeling was set at a temperature at which the reflection density reduction rate (%) became 10% or less.

[0351] Determination of offset temperature offset temperature modulates the fixing temperature to 10 ° C. intervals from 120 ° C., 5 cm × 5 cm to the copy sheet leading edge central portion
Solid image (toner amount 0.5 to 0.6 mg / cm)
^{When the} image formed in ² ) was passed, the temperature at the time when the toner in the solid image portion was peeled off at the rear end of the copy sheet in the paper passing direction and retransfer occurred.

[0352]

[Table 1]

[0353]

[Table 2]

Example 8 The C.I. I. Pigment Blue 15: 3 and C.I. I. A yellow toner N and a two-component developer were obtained in the same manner as in Example 1 except that Pigment Yellow 17 was used.

The C.I. I. Pigment Blue 15: 3, and a magenta toner O and a two-component developer were obtained in the same manner as in Example 1, except that a quinacridone pigment was used as a colorant.

The C.I. I. Pigment Blue 15: 3 and a black toner P and a two-component developer were obtained in the same manner as in Example 1 except that carbon black was used as a coloring agent.

In addition to the two-component developer having the yellow toner N, the two-component developer having the magenta toner O, and the two-component developer having the black toner P, the toner has the cyan toner A of Example 1. When a full-color image was formed using a four-component two-component developer of the two-component developer in the evaluation machine A, excellent color tone and gradation were exhibited, and no contamination to the charging member was observed. Also, the fixability was good.

Example 19 The cyan toner A and yellow toner N used in Example 8
A full-color image was formed using the four types of color toners of magenta toner O and black toner P in the image forming apparatus shown in FIG.

As the charging member, a charging roller having a 16 mm diameter conductive sleeve on which a polyurethane-based elastic layer was formed was used, and the surface of the photoreceptor was primarily charged under the following charging conditions.

Charging conditions Charging bias: Constant current control with an AC current value of 1900 μA Rotational direction and peripheral speed difference of charging roller with respect to photosensitive drum: Followed with photosensitive drum (no difference in peripheral speed) Photoconductor surface potential: -500 V primary The charged photoreceptor surface was irradiated with laser light to form a digital electrostatic latent image.

As the developing device, a developing device using a non-contact developing method using a non-magnetic one-component developer as shown in the figure is used. Was formed. The development operation is
The test was performed four times in the order of yellow, magenta, cyan, and black.

Developing conditions Developing sleeve: Stainless steel sleeve blasted with ^# 600 glass beads Gap between developing sleeve and photosensitive drum β: 500 μm Elastic blade: Urethane rubber plate provided with nylon resin layer on surface Developing on developing sleeve Agent layer thickness: 70 μm Developing bias: AC electric field with a peak voltage of 2 KV Process speed: 150 m / sec

The toner image developed on the photoreceptor is charged four times on the intermediate transfer member in the order of yellow color toner image, magenta color toner image, cyan color toner image, and black color toner image under the following transfer conditions. Transcribed (first
Transfer step) A full-color image having four color toners was electrostatically transferred onto a recording material by one transfer operation (second transfer step) using the transfer member under the following transfer conditions.

As the intermediate transfer member, an intermediate transfer drum having an elastic layer formed on the surface of a conductive drum having a diameter of 186 mm was used.

As the transfer conditions in the first transfer step, a transfer bias of 100 to 200 V was applied to the intermediate transfer drum. As the transfer member in the second transfer step, the diameter 16
mm conductive rubber roller was used.

Transfer conditions in the second transfer step Transfer bias: DC voltage of 1 KV Contact pressure of transfer roller against intermediate transfer member: 1 kgf A full-color image having four color toners transferred onto a recording material was prepared as follows. The image was fixed by heating with a fixing device.

As the fixing device, a heating roller fixing device having a heating roller and an elastic layer capable of modulating the fixing density at intervals of 5 ° C. and having a pressure roller pressed against the heating roller was used.

As a result, high offset resistance, a wide fixing temperature range, and a good full-color image in a wide fixing temperature range were obtained.

(Charging Member Production Example 1) Zn—Cu ferrite having a composition represented by (Fe ₂ O ₃ ) _2.3 (CuO) ₁ (ZnO) ₁ having an average particle diameter of 25 μm was prepared as magnetic particles, When the dependence of the value on the applied electric field was measured, the behavior of A in FIG. 2 was shown. The volume resistance of the magnetic particles was measured by a resistance measuring device using an aluminum drum. 20 at this time
ＶV1 (V / cm) is 10 ⁷ to 10 ⁸ Ωcm,
R1 / R2 was 10.

(Example 2 of Production of Charged Charging Member) Magnetic particles were prepared by coating the surface of the magnetic particles of Production Example 1 of the charged member with a conductive resin in which 1% of carbon black was dispersed in a silicone resin, and the resistance value was measured. When the above method was used, the applied electric field dependence of the resistance value showed the behavior of B in FIG. At this time, 20 to V1 (V / cm) was 10 ⁷ to 10 ⁹ Ωcm, and R1 / R2 was 100.

(Charging Member Production Example 3) Magnetic particles were prepared by subjecting Zn-Cu ferrite of Charging Member Production Example 1 to oxidation treatment, and the resistance was measured by the above-described method. The electric field dependence showed the behavior of C in FIG. At this time, 20 to V1 (V / cm) was 10 ⁹ to 10 ¹¹ Ωcm, and R1 / R2 was 1000.

(Charging Member Production Example 4) Z of Charged Part Production Example 1
Magnetic particles were prepared by coating a conductive resin obtained by dispersing 3% of carbon black in a silicone resin on the surface of magnetic particles obtained by oxidizing n-Cu ferrite, and measuring the resistance value by the above-described method. The dependence of the resistance value on the applied electric field showed the behavior of D in FIG. At this time, 20 to V1 (V
/ Cm) is 10 ⁶ to 10 ⁹ Ωcm, and R1 / R2
Was 1000.

(Charging Member Production Example 5) (Fe ₂ O ₃ ) _2.4 (MnO) 1 (ZnO) _1.1 having an average particle size of 45 μm
When the magnetic particles of Mn-Zn ferrite having the composition represented by the following formula and the surface of which is coated with a silicone resin were prepared and the applied electric field dependence of the resistance value was measured, the behavior of E in FIG. 2 was shown. At this time, 20 to V1 (V / cm) is 10
² to 10 ⁶ Ωcm, and R1 / R2 was 1,000.

(Charging Member Production Example 6) (Fe ₂ O ₃ ) _2.4 (MnO) ₁ (ZnO) _1.1 having an average particle size of 45 μm
When Mn-Zn ferrite magnetic particles having the composition represented by the following formula were prepared and the dependence of the resistance value on the applied electric field was measured, FIG.
The behavior of F was shown. 20-V1 (V / cm) at this time
Is 10 ² to 10 ⁵ Ωcm, and R1 / R2 is 100
Met.

(Production Example 7 of Charging Member) A plain woven sheet was prepared using orange-type split fibers (8 filaments, average fiber diameter of 1 μm) composed of polyethylene terephthalate and nylon 6 and nylon 6 fibers (single fiber, 20 μm). did. After injecting a high-pressure water stream to open the split fibers,
Brushed with sandpaper.

Next, the brushed fiber sheet was impregnated with a 15% by weight aqueous solution of ferric chloride for 1 hour, placed in a closed container filled with pyrrole monomer vapor, and subjected to a polymerization reaction for 3 hours. To form polypyrrole.
After the reaction, it was sufficiently washed with pure water and ethanol and dried at 100 ° C. With respect to the dried fiber sheet, the raised portion was brushed with a rigid brush to uniform the fur.

The above brushed fiber sheet was processed into a strip having a width of 1 cm, and wound around a conductive urethane sponge roller (outer diameter φ12 mm) formed on a stainless steel core bar of φ6 mm.

(Photoreceptor Production Example 1) A photoreceptor (hereinafter referred to as an OPC photoreceptor) using an organic photoconductive substance for negative charging.
The following five functional layers are provided on a 30 mm aluminum cylinder.

The first layer is a conductive particle-dispersed resin layer having a thickness of about 20 μm, which is provided to smooth defects of the aluminum cylinder and to prevent the occurrence of moire due to the reflection of laser exposure. It is.

The second layer is a positive charge injection preventing layer (undercoat layer), which serves to prevent positive charges injected from the aluminum support from canceling out negative charges charged on the surface of the photoreceptor. A medium resistance layer having a thickness of about 1 μm, the resistance of which is adjusted to about 10 ⁶ Ωcm by -66-610-12-nylon resin and methoxymethylated nylon.

The third layer is a charge generation layer, and is a layer having a thickness of about 0.3 μm in which a disazo pigment is dispersed in a resin.
Upon receiving the laser exposure, positive and negative charge pairs are generated.

The fourth layer is a charge transport layer, a layer having a thickness of 25 μm in which hydrazone is dispersed in a polycarbonate resin, and is a P-type semiconductor. Therefore, the negative charges charged on the photoreceptor surface cannot move through this layer, and only the positive charges generated in the charge generation layer can be transported to the photoreceptor surface.

The fifth layer is a charge injection layer, which is a feature of the present invention. The fifth layer increases the contact time between a photocurable acrylic resin and ultrafine SnO ₂ particles, and further increases the contact time between the contact charging member and the photosensitive member.
In this case, ethylene tetrafluoride resin particles having a particle size of about 0.25 μm are dispersed for uniform charging. In particular,
Antimony-doped, low-resistance particle size of about 0.0
3 μm of SnO ₂ particles were added to
7 parts by weight, 20 parts by weight of ethylene tetrafluoride resin particles, and 1.2 parts by weight of a dispersant.

The coating solution thus prepared was applied to a thickness of about 2.5 μm by a spray coating method to form a charge injection layer.

As a result, the volume resistivity of the photoreceptor surface layer was 1 × 10 ¹⁵ Ωcm in the case of the charge transport layer alone, whereas the resistance of the photoreceptor surface was reduced to 5 × 10 ¹² Ωcm. The contact angle of the photoreceptor surface with water was 93 degrees. This photoconductor is referred to as photoconductor 1.

The contact angle was measured using pure water, and the apparatus used was a contact angle meter CA-DS, Kyowa Interface Science Co., Ltd.

(Photoreceptor Production Example 2) The photoreceptor was prepared according to Photoreceptor Production Example 1 up to the undercoat layer. The charge generation layer is
It is mainly composed of a titanyl phthalocyanine pigment having absorption in a long wavelength region dispersed in a butyral resin (a film thickness of 0.7
μm). As the charge transport layer, a material obtained by dissolving a hole transporting triphenylamine compound in a polycarbonate resin at a mass ratio of 10:10 was used (film thickness: 18 μm). Further, as a charge injection layer thereon, a composition in which the same material was dissolved at a mass ratio of 5:10 was mixed with 120 parts by mass of low resistance SnO ₂ particles (particle size: 0.03 μm) per 100 parts by mass of resin. A polytetrafluoroethylene powder (particle diameter: 0.1 μm) was added at 30% by mass with respect to the total solid content, and was uniformly dispersed, and spray-coated on the charge transport layer (thickness: 3).
μm). The resistance of the photoreceptor surface is 2 × 10 ¹³ Ωcm,
The contact angle of the photoreceptor surface with water was 101 degrees. This photoconductor is referred to as photoconductor 2.

(Photoreceptor Production Example 3) A photoreceptor was produced in the same manner as in Photoreceptor Production Example 2, except that polytetrafluoroethylene powder was not added to the charge injection layer (photoreceptor surface layer). The contact angle of the photoreceptor surface with water was 78 degrees.
This photoconductor is referred to as photoconductor 3.

Photoconductor Characteristics: The photoconductor characteristics are measured under the process conditions of an apparatus actually used. The measuring method is such that the surface electrometer probe is disposed immediately after the exposure position, and the potential of the photoconductor without exposure is Vd.

Next, the exposure intensity is gradually changed, and the surface potential of the photosensitive member is recorded. The half-exposure intensity means the exposure intensity at the time when the potential of the photoconductor becomes half of the potential of the dark portion, that is, Vd / 2.

Further, the potential at the time of exposure with a light amount 30 times the half-reduced exposure intensity is defined as a residual potential Vr.

A laser beam printer (manufactured by Canon: LBP-
860). Process speed is 47mm /
s. The latent image was formed at 300 dpi and binary. In this embodiment, a DC voltage is applied by replacing the photosensitive member charging member with a magnetic brush roll charging member.

The photoreceptor characteristics were measured by changing the amount of laser light and monitoring the potential. At this time, in the laser exposure, the entire surface is exposed by continuous light emission in the sub-scanning direction.

In the measurement of the photoreceptor of the photoreceptor production example 1, the dark area potential was -700 V, the light quantity at which the dark area potential was reduced by half, the half light quantity of the photoreceptor was 0.38 cJ / m ² , and the residual potential Vr
Is −55 V, the slope of the straight line connecting Vd and (Vd + Vr) / 2 is 920 Vm ² / cJ, and the 1/20 slope is 45
m ² / cJ. The contact point between the photosensitive member characteristic curve and the 1/20 slope is 1.55 cJ / m ^2, which is 5
1.90 cJ / m ² . A graph of the photoconductor characteristics is shown in FIG. Further, the same measurement was performed on the photoconductors of Photoconductor Production Examples 2 and 3. The results are shown in Table 3 below.

[0395]

[Table 3]

Example 10 170 parts by weight of styrene 30 parts by weight of n-butyl acrylate 10 parts by weight of carbon black 3 parts by weight of ditertiary butylsalicylic acid AI compound 10 parts by weight of saturated polyester (acid value 10, peak molecular weight 9, 100) ・ Ester wax 40 parts by weight (Mw: 450, M
n: 400, Mw / Mn: 1.13, DSC maximum endothermic peak: 68 ° C., viscosity: 6.1 mPa · s, Vickers hardness: 1.2, SP value: 8.3) divinylbenzene
0.5 parts by weight

The above disposal was heated to 55 ° C., and 10,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo).
To dissolve and disperse uniformly. In addition, polymerization initiator 2,
2'-azobis (2,4-dimethylvaleronitrile) 4
A part by weight was dissolved to prepare a polymerizable monomer composition.

Separately, 0.10 parts by weight of ion-exchanged water
450 parts by weight of an aqueous solution of M-Na ₃ PO ₄
TK homomixer (manufactured by Tokushu Kika Kogyo)
And stirred at 1,300 rpm. To this 1.
It was added gradually 0M-CaCl ₂ aqueous solution 68 parts by weight, C
An aqueous medium containing a ₃ (PO ₄ ) ₂ was obtained.

The above polymerizable monomer composition was charged into this aqueous medium, and 2 parts by weight of polyethylene was added.
Under a N ₂ atmosphere at ℃ 1 with a TK homomixer
The mixture was stirred at 000 rpm for 20 minutes to granulate the polymerizable monomer composition. Thereafter, while stirring the aqueous medium with a paddle stirring blade, the reaction was carried out at 55 ° C. for 1 hour, the temperature was raised to 60 ° C. in 1 hour, and after 4 hours, the temperature was raised at a rate of 40 ° C./Hr. The temperature was raised to 80 ° C., and a polymerization reaction was performed for 4 hours. Nitrogen was bubbled into the hydrogen medium during the polymerization reaction every hour to adjust the dissolved oxygen concentration in the aqueous medium to 0.5 to 1.0 mg / l.

After the completion of the polymerization reaction, the mixture was cooled, hydrochloric acid was added to dissolve calcium phosphate, and then filtered, washed with water and dried to obtain black polymer particles (black toner particles) having a weight average particle size of 6.8 μm. Obtained black toner particles 10
To 0 part by weight, 1.0 part by weight of silica fine powder subjected to hydrophobic treatment with silicone oil and 1.0 part by weight of hydrophobic titanium oxide fine particles were added and mixed with a Henschel mixer to obtain a black toner AA.

Further, a two-component developer AA was prepared by mixing the black toner AA and the ferrite carrier (average particle size: 50 μm) at a ratio of 7: 100.

Table 4 shows the properties of the black toner AA.

A digital copying machine (GP55, manufactured by Canon) was prepared as an electrophotographic apparatus. This copier was modified as follows.

The process was modified so as to increase the process speed by 1.5 times, and the latent image was formed as a 300 dpi on-off digital latent image.

As the contact charging member, the magnetic particles used in the charging member manufacturing example 1 were used, and a magnet roll was placed in a conductive sleeve obtained by blasting the surface of a non-magnetic aluminum sleeve for raising the particles as a magnetic brush. A gap between the surface of the conductive sleeve and the surface of the photoconductor is set to about 500 μm, and the magnetic particles are formed on the surface of the photoconductor so that a charging nip having a width of about 5 mm is formed on the surface of the photoconductor. Then, the magnetic brush was formed by the magnetic restraint of a magnet roll. The surface of the sleeve was rotated so as to be rubbed at a speed of 200% in the direction opposite to the rotation direction of the photoconductor so that the surface of the photoconductor was uniformly contacted with the magnetic brush.

Here, when the peripheral speed of the photosensitive member is V and the peripheral speed of the charging member is v at the contact portion between the charging member and the photosensitive member, the peripheral speed difference is given by: peripheral speed difference = (| V−v | / | V |) × 100.

[0407] The magnetic flux density (B) of the magnet roll is equal to 0.
At 09T, the pole showing the maximum magnetic flux density was fixed at a position facing the photoconductor. 0.09 of the magnetic particles of the charging member production example 1
The magnetization (σ _B ) at T is about 58 (Am ² / kg) and B · σ _B is 5.22.

When the magnetic brush is fixed, since the magnetic brush itself has no physical restoring force, the nip of the magnetic brush can be secured when the magnetic brush is pushed away due to deflection or eccentricity of the photoconductor. It tends to disappear and may cause poor charging. For this reason, it is preferable to always apply a new magnetic brush surface, and in this embodiment, charging is performed using a charging device that rotates in the opposite direction at twice the speed.

Further, the developing portion of the process cartridge was modified. A medium resistance rubber roller (φ16 mm) made of urethane foam was used as a toner carrier instead of the stainless steel sleeve as the toner supply body, and was brought into contact with the photoconductor. The peripheral speed of rotation of the toner carrier is the same in the contact portion with the photoconductor, and is 18 to the peripheral speed of the photoconductor.
Drive is performed so as to be 0%.

[0410] As means for applying toner to the toner carrier, an application roller was provided at the developing portion and was brought into contact with the toner carrier. Further, a stainless steel blade coated with a resin was attached to control the coat layer of the toner on the toner carrier. In addition, the applied voltage during development is changed to a DC component (−
300 V) only.

In a copying machine obtained by modifying the above-mentioned GP55, a continuous image forming test of 50,000 sheets was performed using the two-component developer AA, and the image quality, durability and contamination of the charging member were evaluated.

Image quality The image quality was evaluated by visually observing the tone reproducibility after continuous printing of 50,000 sheets (image with a printing ratio of 5.24%) and based on the following evaluation criteria.

(Evaluation Criteria) A: Excellent B: Good C: Normal D: Somewhat bad E: Bad

[0414] Durability durability, following evaluation of an image density change when subjected 50,000 sheets of continuous paper feed at the GP55 remodeled machine (printing ratio 5.24% image having a solid portion with a diameter of 5mm) The evaluation was based on criteria.

Regarding the image density, a solid portion having a diameter of 5 mm was measured with a Macbeth densitometer (manufactured by Macbeth).

(Evaluation Criteria) A: Image density more than 1.50 B: Image density more than 1.20 to 1.50 C: Image density more than 1.10 to 1.20 D: Image density more than 1.00 to 1. 10 E: Image density 1.00 or less

[0417] Contamination of the charging member The contamination of the charging member was visually observed after passing through 50,000 sheets continuously (image with a printing ratio of 5.24%) by the above-mentioned GP55 modified machine. Was evaluated based on the evaluation criteria.

(Evaluation Criteria) A: No contamination on the surface of the charging member B: Dirt was confirmed on about 30% of the surface of the charging member C: Dirt was confirmed on about 50% of the surface of the charging member D: A state in which dirt is confirmed on about 70% of the charging member surface E: A state in which dirt is entirely confirmed on the charging member surface

Further, an unfixed image is formed on the recording material using a copier modified from the above GP55, and the unfixed image is fixed on the recording material using the following external fixing device. And the offset temperature were measured, and the fixability was evaluated.

The fixing of the unfixed image formed on the recording material is performed by
A fixing unit of a commercially available NP-6650 (manufactured by Canon Inc.) was set to a fixing speed of 150 mm / sec, and the fixing temperature was set to 5 ° C.
The one modified so as to be able to modulate every other time (120 ° C. to 220 ° C.) was used. As a recording material, a commercially available copy paper, Canon New Dry Paper (available from a Canon sales company, landfill: 54 g / m ² ) was used.

The following evaluation items were evaluated.

Fixing start temperature The fixing start temperature was determined by modulating the fixing temperature every 120 ° C. to 5 ° C., and the obtained fixed image was rubbed with silbon paper 10 times in a reciprocating manner at a load of about 100 g. Image peeling was set at a temperature at which the reflection density reduction rate (%) became 10% or less.

[0423] Determination of offset temperature offset temperature modulates the fixing temperature to 10 ° C. intervals from 120 ° C., 5 cm × 5 cm to the copy sheet leading edge central portion
Solid image (toner amount 0.5 to 0.6 mg / cm)
The temperature of the solid image was peeled off at the rear end of the copy sheet in the sheet passing direction when the sheet prepared in ² ) was passed, and the temperature was set at the point of retransfer.

Further, the storage stability of the black toner A was evaluated.

[0425] The storage stability was determined by adding 5 parts of black toner A to a polycup on a cylinder.
g After placing in a 30 ° C./80% Rh environment for 1 week, the poly cup is rotated at a 45 ° angle while the poly cup is rotated once while maintaining the 45 ° angle. It was observed visually and evaluated based on the following evaluation criteria.

(Evaluation Criteria) A: Toner dissolves quickly B: Toner dissolves about 70% C: Toner dissolves about 50% D: Toner dissolves about 30% E: Toner completely Table 6 shows the evaluation results that cannot be understood.

Example 11 Styrene 170 parts by weight 2-Ethylhexyl acrylate 30 parts by weight Copper phthalocyanine pigment 15 parts by weight Cr ditertiary butylsalicylate compound 3 parts by weight Saturated polyester 10 parts by weight (acid value 10, peak molecular weight 9) , 100) ・ Ester wax 30 parts by weight (Mw: 500, M
n: 400, Mw / Mn: 1.25, DSC maximum endothermic peak: 70 ° C., viscosity: 6.5 mPa · s, Vickers hardness: 1.1, SP value: 8.6) 0.2 parts by weight of divinylbenzene

Except that the above formulation was used, cyan polymer particles (cyan toner particles) having a weight average particle size of 6.3 μm were obtained in the same manner as in Example 10. The obtained cyan toner particles were mixed with silica fine powder subjected to hydrophobic treatment with silicone oil in the same manner as in Example 10 to obtain a cyan toner BB having the physical properties shown in Table 3. A ferrite carrier was mixed with the obtained cyan toner BB in the same manner as in Example 10 to prepare a two-component developer BB.

Evaluation was carried out in the same manner as in Example 10 except that the two-component developer BB was used instead of the two-component developer AA used in Example 10.

The results of the evaluation are shown in Table 6.

Comparative Example 17 170 parts by weight of styrene 30 parts by weight of 2-ethylhexyl acrylate 15 parts by weight of carbon black pigment 3 parts by weight of monoazo type Fe complex 10 parts by weight of saturated polyester (acid value 10, peak molecular weight 9,100) )-30 parts by weight of paraffin wax (Mw: 570, M
n: 380, Mw / Mn: 1.50, DSC maximum endothermic peak: 69 ° C., viscosity: 6.8 Pa · s, Vickers hardness: 0.7, SP value: 8.3) 0.28 parts by weight of divinylbenzene

A polymerizable monomer composition was prepared in the same manner as in Example 10 and charged into the aqueous medium prepared in Example 10, except that polyethylene was not added. Black polymer particles (black toner particles) having an average particle size of 7.4 μm were obtained. The obtained black toner particles were mixed with silica fine powder subjected to hydrophobic treatment with silicone oil in the same manner as in Example 10 to obtain a black toner CC having the physical properties shown in Table 3. A ferrite carrier was mixed with the obtained black toner CC in the same manner as in Example 10 to prepare a two-component developer CC.

The evaluation was performed in the same manner as in Example 10 except that the two-component developer CC was used instead of the two-component developer AA used in Example 10.

Table 6 shows the results of the evaluation.

Comparative Example 18 170 parts by weight of styrene 30 parts by weight of 2-ethylhexyl acrylate 15 parts by weight of quinacridone pigment 3 parts by weight of a chromium ditertiarybutylsalicylate compound 10 parts by weight of a saturated polyester (acid value 10, peak molecular weight 9, 100) ・ 30 parts by weight of carnauba wax (Mw: 900, M
n: 530, Mw / Mn: 1.70, DSC maximum endothermic peak: 65 ° C., viscosity: 6.3 mPa · s, Vickers hardness: 6.8, SP value: 8.7) ・ divinylbenzene 0.20 part by weight

Magenta polymer particles (magenta toner particles) having a weight average particle size of 6.6 μm were obtained in the same manner as in Example 10 except that the above formulation was used. The obtained magenta toner particles were mixed with silica fine powder which had been subjected to hydrophobic treatment with silicone oil in the same manner as in Example 10 to obtain a magenta toner DD having the physical properties shown in Table 3. A ferrite carrier was mixed with the obtained magenta toner DD in the same manner as in Example 10 to prepare a two-component developer DD.

The evaluation was performed in the same manner as in Example 10 except that the two-component developer DD was used instead of the two-component developer AA used in Example 10.

The results of the evaluation are shown in Table 6.

Comparative Example 19 A polymerizable monomer composition was prepared in the same manner as in Example 10 except that the amount of the polymerization initiator 2.2'-azobis (2.4-dimethylpareronitrile) was changed to 3 parts by weight. .

The temperature of the aqueous medium was changed to 60 ° C. without adding polyethylene during granulation of the polymerizable monomer composition, and after granulation, the temperature was raised to 80 ° C. in 1 hour while stirring with a paddle stirring blade. Change the polymerization conditions to raise the temperature and react for 10 hours,
Further, black polymer particles (black toner particles) were obtained in the same manner as in Example 10, except that nitrogen was not bubbled into the hydrogen medium during the polymerization reaction. The obtained black toner particles were mixed with silica fine powder subjected to hydrophobic treatment with silicone oil in the same manner as in Example 10 to obtain a black toner EE having the physical properties shown in Table 3. The obtained black toner EE was mixed with a ferrite carrier in the same manner as in Example 10 to prepare a two-component developer EE.

The evaluation was performed in the same manner as in Example 10 except that the two-component developer EE was used instead of the two-component developer AA used in Example 10.

The results of the evaluation are shown in Table 6.

Comparative Example 20 (monomer) 170 parts by weight of styrene 30 parts by weight of 2-ethylhexyl acrylate (colorant) 10 parts by weight of carbon black (charge control agent) Al compound of ditert-butylsalicylic acid 3 parts by weight (release agent) Paraffin wax 30 parts by weight (DSC maximum endothermic peak: 70 ° C.) (Polymerization initiator) 2,2′-azobis (2.4-dimethylvaleronitrile) 10 parts by weight dimethyl 2.2′-azobisisisobutyrate 1 part by weight

The above formulation was heated to 60 ° C., and uniformly dissolved and dispersed at 9,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare a polymerized monomer composition.

In place of the polymerizable monomer composition used in Example 10, a higher polymerizable monomer composition was used, and the temperature of the aqueous medium was changed to 60 ° C. without adding polyethylene during granulation. Then, after granulation for 1 hour, while stirring with paddle stirring blades, 6
After reacting at 0 ° C for 7 hours, the temperature was raised to 80 ° C in 0.5 hours,
The polymerization conditions were changed so as to allow the reaction to proceed for a period of time, and black polymer particles (black toner) were prepared in the same manner as in Example 10 except that nitrogen was not bubbled into the aqueous medium during the polymerization reaction. Particles). The obtained black toner particles were mixed with silica fine powder subjected to hydrophobic treatment with silicone oil in the same manner as in Example 10 to obtain a black toner FF having the physical properties shown in Table 3. The obtained black toner FF was mixed with a ferrite carrier in the same manner as in Example 10 to prepare a two-component developer FF.

Evaluation was performed in the same manner as in Example 10 except that the two-component developer FF was used instead of the two-component developer AA used in Example 10.

The results of the evaluation are shown in Table 6.

Example 12 170 parts by weight of styrene 30 parts by weight of n-butyl acrylate 15 parts by weight of quinacridone pigment 3 parts by weight of a Cr compound of ditertiary butylsalicylate 3 parts by weight of saturated polyester 10 parts by weight (acid value 10, peak molecular weight 9, 100) 30 parts by weight of diester wax (Mw: 480, M
n: 410, Mw / Mn: 1.17, melting point: 73 ° C., viscosity: 10.5 mPa · s, Vickers hardness: 1.0, S
P value: 9.1) 0.18 parts by weight of divinylbenzene

A polymerizable monomer composition was prepared in the same manner as in Example 10 and charged into the aqueous medium prepared in Example 10. The polymerization reaction time at 80 ° C. without adding polyethylene was added. Was changed from 4 hours to 6 hours to obtain magenta polymer particles (magenta toner particles) having a weight average particle size of 6.9 μm through the same steps as described below. The obtained magenta toner particles were mixed with silica fine powder that had been subjected to a hydrophobic treatment with silicone oil in the same manner as in Example 10 to obtain a magenta toner GG having the physical properties shown in Table 3. A ferrite carrier was mixed with the obtained magenta toner GG in the same manner as in Example 10 to prepare a two-component developer GG.

Evaluation was carried out in the same manner as in Example 10 except that the two-component developer GG was used instead of the two-component developer AA used in Example 10.

Table 6 shows the results of the evaluation.

Example 13 170 parts by weight of styrene 30 parts by weight of 2-ethylhexyl acrylate 15 parts by weight of copper phthalocyanine pigment 3 parts by weight of an aluminum ditert-butylsalicylate compound 10 parts by weight of a saturated polyester (acid value 10, peak molecular weight 9) , 100) ・ Ester wax 30 parts by weight (Mw: 450, M
n: 400, Mw / Mn: 1.25, melting point: 70 ° C., viscosity: 6.5 mPa · s, Vickers hardness: 1.1, SP
Value: 8.6) 0.20 parts by weight of divinylbenzene

Except that the above formulation was used, cyan polymer particles (cyan toner particles) having a weight average particle size of 6.8 μm were obtained in the same manner as in Example 10. The obtained cyan toner particles were mixed with silica fine powder subjected to hydrophobic treatment with silicone oil in the same manner as in Example 10 to obtain a cyan toner HH having the physical properties shown in Table 3. A ferrite carrier was mixed with the obtained cyan toner HH in the same manner as in Example 10 to prepare a two-component developer HH.

Evaluation was carried out in the same manner as in Example 10 except that the two-component developer HA was used instead of the two-component developer AA used in Example 10.

Table 6 shows the results of the evaluation.

Example 14 As shown in Table 5, the magnetic particles used in Example 10 were replaced with the magnetic particles used in Example 3, and the magnetic particles used in Example 3 were used as the charging member. Photoconductor production example 3 as shown
Example 1 except that the photoreceptor 3 produced in was used.
The evaluation was performed using a copying machine that was modified in the same manner as in Example 1. Table 6 shows the evaluation results.

Comparative Examples 21 and 22 Table 5 was used in place of the magnetic particles used in Example 10 for the charging member.
The two-component developer used in Comparative Examples 17 and 18 was used in a copier modified as shown in Example 10 using the magnetic particles produced in Charging Member Production Example 2 and Charging Member Production Example 4 as shown in FIG. Table 6 shows the results of evaluation using CC and DD in the same manner as in Example 10.

Example 15 Table 5 was used instead of the magnetic particles used in Example 10 for the charging member.
As shown in FIG. 11, a two-component developer BB used in Example 11 was used in a copier modified as shown in Example 10 using magnetic particles produced in Charging Member Production Line 2, and Table 6 shows the results of each evaluation in the same manner as in Example 10.

Examples 16 and 17 The same evaluation as in Example 10 was performed except that the magnetic particles used in Production Examples 5 and 6 were used instead of the magnetic particles used in the charging member in Example 10. Was. Table 6 shows the results of each evaluation.

Example 18 Instead of the charging member used in Example 10, a fur brush roll prepared in Production Example 7 of the charging member was used, and the fur brush having a width of about 5 mm was formed between the fur brush and the photosensitive member during image formation. It was arranged to form a charging nip. The fur brush roll was rotated at a speed of 250% so as to be rubbed in the direction opposite to the photoconductor rotation direction, so that the photoconductor and the fur brush were in uniform contact. Photoconductor 2 manufactured in Photoconductor Manufacturing Example 2 was used instead of Photoconductor 1.

Table 6 shows the results of the evaluation of the two-component developer AA used in Example 10 in the same manner as in Example 10 using the copier thus modified.

[0462]

[Table 4]

[0463]

[Table 5]

[0464]

[Table 6]

Example 19 In place of carbon black used in Example 10, C.I. I. A yellow toner II and a two-component developer were obtained in the same manner as in Example 10 except that Pigment Yellow 17 was used.

A magenta toner JJ and a two-component developer were obtained in the same manner as in Example 10, except that a quinacridone pigment was used as a colorant instead of the carbon black used in Example 10.

In place of carbon black used in Example 1, C.I. A cyan toner KK and a two-component developer were obtained in the same manner as in Example 10 except that I Pigment Blue 15: 3 was used.

In addition to the two-component developer having the yellow toner II, the two-component developer having the magenta toner JJ, and the two-component developer having the cyan toner KK, the toner having the black toner AA of Example 10 is provided. A full-color image was formed using four-component two-component developers in the full-color image forming apparatus shown in FIG.

The image forming apparatus shown in FIG. 7 includes a two-component developer having the yellow toner II in the first image forming unit Pa, a two-component developer having the azenda toner JJ in the second image forming unit Pb, Four-component developer having cyan toner KK in image forming unit Pc;
A two-component developer having a black toner AA was used for the image forming unit Pd.

Each of the image forming units Pa, Pb, Pc, and Pd uses the magnetic particles used in the charging member manufacturing example 1 as a charging member, and forms a magnetic brush on the surface of a nonmagnetic aluminum sleeve for raising the magnetic brush. Using a conductive sleeve with a magnet roll encased in a plasted conductive sleeve, the gap between the conductive sleeve surface and the photoreceptor surface is set to about 500 μm, and the magnetic particles are charged to a width of about 5 mm on the photoreceptor surface. A magnetic brush was formed on the conductive sleeve by magnetically constraining a magnet roll so as to form a nip. 200% sleeve surface
The surface of the photoreceptor was uniformly contacted with the magnetic brush by rotating the photoreceptor so as to rub it in the direction opposite to the rotational direction of the photoreceptor.

Here, when the peripheral speed difference is V and the charging member peripheral speed is v at the contact portion between the charging member and the photosensitive member, the peripheral speed difference = (| V−v | / | V |) × 100.

[0472] The magnetic flux density (B) of the magnet roll is equal to 0.
At 09T, the pole showing the maximum magnetic flux density was fixed at a position facing the photoconductor. 0.09 of the magnetic particles of the charging member production example 1
The magnetization (σ _B ) at T is about 58 (Am ² / kg) and B · σ _B is 5.22.

When the magnetic brush is fixed, the magnetic brush itself does not have a physical restoring force. Therefore, when the magnetic brush is pushed away due to deflection or eccentricity of the photosensitive member, the nip of the magnetic brush can be secured. It tends to disappear and may cause poor charging. For this reason, it is preferable to always apply a new magnetic brush surface. In this embodiment, charging is performed using a charging device that is rotated at twice the speed in the reverse direction.

As the photoconductor, the photoconductor manufactured in Photoconductor Manufacturing Example 1 was used, and a charging bias voltage of an AC component having a peak voltage of 2 Kv was applied to the conductive sleeve to primary charge the photoconductor surface voltage to 500V. .

The surface of the primary charged photosensitive member was irradiated with a laser beam to form a digital electrostatic latent image having a residual potential of 350V.

As a developing device, a developing device using a dry two-component contact developing system using a two-component developer as shown in FIG. 10 is used. The digital electrostatic latent image on the photosensitive member is subjected to reversal development under the following developing conditions. The toner image formation was carried out.

Developing conditions Developing sleeve: SUS sleeve developing surface blasted with ^# 600 glass beads, air gap between photosensitive drum and P: 550 μm Elastic blade: Urethane rubber blade provided with nylon resin layer on surface Developer layer thickness on sleeve: 70 μm Development bias: AC voltage with peak voltage of 2 Kv Process speed: 180 m / sec

The toner images developed on the respective photosensitive members were sequentially subjected to electrostatic transfer on the conveyed recording material, and a full-color image having four color toners was electrostatically transferred onto the recording material.

Transfer conditions : Transfer bias: From the first image forming unit to the fourth image forming unit, the transfer bias is gradually increased from 0.8 to
A DC voltage of 1.2 KV was applied.

A full-color image having four color toners transferred onto a recording material was heat-fixed by the following fixing device.

As a fixing device, a heating roller fixing device having a heating roller set at a predetermined temperature and an elastic layer, and having a pressure roller pressed against the heating roller was used.

As a result, toner characteristics having a high offset resistance and a wide fixing temperature range were obtained. In addition, sufficient color mixing properties and excellent chroma of the color exhibited by the formation of the multilayer toner were obtained, and the quality of a full-color image was improved.

[0483]

As described above, the electrostatic charge developing toner of the present invention can be used for filming on a photoreceptor, carrier or toner without deteriorating characteristics excellent in low-temperature fixability and offset resistance. The surface of the toner carrier such as a sleeve is not easily contaminated, and the durability of a large number of sheets is excellent.

[Brief description of the drawings]

FIG. 1 shows the GP of magenta toner particles in Example 12.
The figure which shows the chart of the molecular weight distribution of C.

FIG. 2 is a graph showing the applied electric field dependence of the resistance value of the magnetic particles of the charging member production examples 1 to 8.

FIG. 3 is a graph showing photoconductor characteristics of Photoconductor Manufacturing Example 1.

FIG. 4 is a schematic view of an apparatus used for a method for measuring magnetic particles as a charging member.

FIG. 5 is a schematic diagram of a developing device used for durability evaluation in Examples.

FIG. 6 is an explanatory diagram of an apparatus for measuring a triboelectric charge amount of a toner.

FIG. 7 is a schematic diagram illustrating an image forming apparatus used in the present invention.

FIG. 8 is a schematic diagram of a first image forming unit.

FIG. 9 is a schematic view illustrating another example of the image forming apparatus used in the present invention.

FIG. 10 is a schematic diagram of an image forming apparatus using a two-component developer.

FIG. 11 is a schematic view of a developing device using a contact one-component developing method.

FIG. 12 is a schematic diagram of a developing device using a non-contact one-component developing method.

[Explanation of symbols]

Pa, Pb, Pc, Pd Image forming units 1a, 1b, 1c, 1d Photosensitive drums 2a, 2b, 2c, 2d Drum chargers 3a, 3b, 3c, 3d Developers 4a, 4b, 4c, 4d Transfer chargers 5a, 5b, 5c, 5d Photosensitive band cleaning unit 6 Recording material 7 Fixing unit 8 Recording material carrier 9 Transfer cleaning device 10 Belt drive roller 11 Belt driven roller 12 Belt neutralizer 13 Registration roller 14 Separation charger 15 Peeling charger 16 Fur brush 17 Polygon mirror 18 Separation claw 21a, 21b, 21c, 21d Exposure lamp 22a, 22b, 22c, 22d Potential sensor 31a, 31b, 31c, 31d Photo sensor 41a, 41b, 41c, 41d Transfer pressing member 51 Developing device 52 Photoconductor 53 Corona transfer charger 54 Transfer material 55 Roller Charger 56 Exposure 60 Recording paper cassette 71 Fixing roller 72 Pressure roller 73 Cleaning device 74 Cleaning device 75 Heater 76 Heater 77 Oil application roller 78 Oil reservoir 79 Thermistor 91 Sleeve 91-a Conductive sleeve 91-b Magnet roll 92 Aluminum Drum 93 Nip width between charging member and aluminum drum 94 Gap between magnet enclosing sleeve and aluminum drum 95 Ammeter 96 Constant voltage device 97 Magnetic particles serving as charging member

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI G03G 13/06 G03G 15/02 101 13/16 15/08 507L 15/02 101 15/01 J 15/08 507 9/08 361 // G03G 15/01 365 384

Claims (58)

[Claims] 1. An electrostatic image developing toner containing at least a binder resin, a colorant and a release agent, wherein the THF-soluble component of the toner has a molecular weight distribution determined by gel permeation chromatography (GPC).
The THF-soluble component has a molecular weight of 1,000 to 2,000.
Has at least one peak in a region having a molecular weight of less than 2,000 to 300,000.
90,000-2,000,
000 having a weight average molecular weight (Mw) of 8,000 and a molecular weight integrated value (T) of a region having a molecular weight of 800 or more;
A molecular weight integrated value (L) in the range of 000 to 5,000;
Molecular weight integrated value (H) in the region of molecular weight 300,000 or more
Satisfies the following relationship: 1 ≦ (L / T) × 100 ≦ 153 3 ≦ (H / T) × 100 ≦ 30. 2. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a molecular weight of 8
The molecular weight integrated value (T) of the region of 00 or more and the molecular weight of 2,0
The molecular weight integrated value (L) in the region of 00 to 5,000 and the molecular weight integrated value (H) in the region of 300,000 or more have the following relationship: 1 ≦ (L / T) × 100 ≦ 73 ≦ ( 2. The electrostatic image developing toner according to claim 1, wherein the following condition is satisfied: H / T) × 100 ≦ 30. 3. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a molecular weight of 8
The molecular weight integrated value (T) of the region of 00 or more and the molecular weight of 2,0
The molecular weight integral (L) in the region of 00 to 5,000 and the molecular weight integral (H) in the region of 300,000 or more have the following relationship: 1 ≦ (L / T) × 100 ≦ 75 ≦ ( 2. The electrostatic image developing toner according to claim 1, wherein H / T) × 100 ≦ 25 is satisfied. 4. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a molecular weight of 8
The molecular weight integrated value (T) of the region of 00 or more and the molecular weight of 10
The molecular weight integral value (M) in the region of 000 or more satisfies the following relationship: 10 ≦ (M / T) × 100 ≦ 50. An electrostatic image developing toner. 5. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a molecular weight of 8
The molecular weight integrated value (T) of the region of 00 or more and the molecular weight of 10
The molecular weight integrated value (M) in the region of 000 or more satisfies the following relationship: 15 ≦ (M / T) × 100 ≦ 40. An electrostatic image developing toner. 6. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a top peak height (Ha) and a molecular weight of 2,000 in a region having a molecular weight of 1,000 to less than 2,000. 000-300,000
The electrostatic charge according to any one of claims 1 to 5, wherein the height (Hb) of the top peak in the region (1) satisfies the following relationship: 0.70 ≦ Hb / Ha ≦ 1.30. Image developing toner. 7. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a top peak height (Ha) and a molecular weight of 2,7 to less than 1,000 to less than 2,000. 000-300,000
The height (Hb) of the top peak in the region of (1) satisfies the following relationship: 0.75 ≦ Hb / Ha ≦ 1.25. The electrostatic charge according to claim 1, wherein: Image developing toner. 8. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a top peak in a region having a molecular weight of 1,000 to less than 2,000 and a top peak having a molecular weight of 2,000 to 300,000. Height of the molecular weight minimum existing between the top peak in the region (H
c) wherein the height (Ha) of the top peak in the region having a molecular weight of 1,000 to less than 2,000 satisfies the following relationship: 0.01 ≦ Hc / Ha ≦ 0.15. Item 8. The toner for developing an electrostatic image according to any one of Items 1 to 7. 9. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a top peak in a region having a molecular weight of less than 1,000 to 2,000 and a peak having a molecular weight of 2,000 to 300,000. Height of the molecular weight minimum existing between the top peak in the region (H
c) and the height (Ha) of the top peak in a region having a molecular weight of 1,000 to less than 2,000 satisfies the following relationship: 0.01 ≦ Hc / Ha ≦ 0.10. Item 8. The toner for developing an electrostatic image according to any one of Items 1 to 7. 10. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component is 10% or less.
Weight average molecular weight (M.
The toner for developing an electrostatic charge image according to claim 1, wherein w) is satisfied. 11. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component is 8,2.
The electrostatic image developing toner according to any one of claims 1 to 10, wherein the toner has a number average molecular weight (Mn) of 00 to 700,000. 12. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component is 4 to 1%.
The electrostatic image developing toner according to any one of claims 1 to 11, wherein the toner has a weight average molecular weight / number average molecular weight (Mw / Mn) of 5. 13. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a weight average molecular weight / number average molecular weight (Mw / Mn) in the range of 800 to 3,000. 13. The electrostatic image developing toner according to claim 1, wherein the value is 0 or less. 14. The toner according to claim 1, wherein the resin component of the toner contains 2 to 30% by weight of a toluene-soluble component based on the weight of the resin component. The toner for developing an electrostatic image according to the above. 15. The toner according to claim 1, wherein the resin component of the toner contains 3 to 25% by weight of a toluene-soluble component based on the weight of the resin component. The toner for developing an electrostatic image according to the above. 16. The method according to claim 1, wherein the release agent has a wax having a maximum endothermic peak measured by DSC in a range of 40 ° C. to 120 ° C. An electrostatic image developing toner. 17. The method according to claim 1, wherein the release agent has a wax having a maximum endothermic peak measured by DSC in a range of 40 ° C. to 90 ° C. An electrostatic image developing toner. 18. The toner according to claim 1, wherein the toner contains 3 to 40 parts by weight of the release agent based on 100 parts by weight of the binder resin. Charge image developing toner. 19. The toner according to claim 1, wherein the toner has toner particles having a core / shell structure in which a surface of a core portion of the release agent is covered with a shell portion of a shell resin. The toner for developing electrostatic images according to any one of the above. 20. The toner is obtained by polymerizing a polymerizable monomer composition containing at least a polymerizable monomer, a colorant and a release agent in a liquid medium in the presence of a polymerization initiator. 20. It has toner particles.
The toner for developing electrostatic images according to any one of the above. 21. The toner is obtained by polymerizing a polymerizable monomer composition containing at least a polymerizable monomer, a colorant and a release agent in an aqueous medium in the presence of a polymerization initiator. 2. The image forming apparatus according to claim 1, further comprising toner particles.
10. The toner for developing an electrostatic image according to any one of items 9 to 9. 22. The toner, comprising: a polymerizable monomer, a colorant,
It has toner particles obtained by polymerizing a polymerizable monomer composition containing at least a release agent and a polar resin in an aqueous medium in the presence of a polymerization initiator. 20. The electrostatic image developing toner according to claim 1, wherein the toner has a core / shell structure in which a surface of a core portion of the agent is covered with a shell portion of an outer shell resin. 23. The toner for developing an electrostatic image according to claim 1, wherein the toner is used as a one-component developer. 24. The toner for developing an electrostatic image according to claim 1, wherein the toner is used as a two-component developer by being mixed with carrier particles. 25. A step of charging a surface of a latent image holding member for holding an electrostatic latent image; a step of forming an electrostatic latent image on the charged surface of the latent image holding member; Developing the toner image with a toner to form a toner image; transferring the developed toner image to a recording material with or without an intermediate transfer member; and fixing the transferred toner image to the recording material. The toner contains at least a binder resin, a colorant and a release agent, and a molecular weight distribution of a THF-soluble component of the toner by gel permeation chromatography (GPC). At
The THF-soluble component has a molecular weight of 1,000 to 2,000.
Has at least one peak in a region having a molecular weight of less than 2,000 to 300,000.
90,000-2,000,
It has a weight average molecular weight (Mw) of 000, a molecular weight integrated value (T) of a region having a molecular weight of 800 or more, and a molecular weight of 2,0.
The molecular weight integrated value (L) in the region of 00 to 5,000 and the molecular weight integrated value (H) in the region of 300,000 or more have the following relationship: 1 ≦ (L / T) × 100 ≦ 153 ≦ ( H / T) × 100 ≦ 30. 26. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a molecular weight integrated value (T) in a region having a molecular weight of 800 or more, a molecular weight of 2,
A molecular weight integrated value (L) in the range of 000 to 5,000;
Molecular weight integrated value (H) in the region of molecular weight 300,000 or more
26. The image forming method according to claim 25, wherein the following relationship is satisfied: 1 ≦ (L / T) × 100 ≦ 73 ≦ (H / T) × 100 ≦ 30. 27. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a molecular weight integrated value (T) of a region having a molecular weight of 800 or more, a molecular weight of 2,
A molecular weight integrated value (L) in the range of 000 to 5,000;
Molecular weight integrated value (H) in the region of molecular weight 300,000 or more
26. The image forming method according to claim 25, wherein the following relationship is satisfied: 1 ≦ (L / T) × 100 ≦ 75 ≦ (H / T) × 100 ≦ 25. 28. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a molecular weight integrated value (T) in a region having a molecular weight of 800 or more and a molecular weight of 10
28. The method according to claim 25, wherein the molecular weight integral value (M) in the region of 000 or more satisfies the following relationship: 10 ≦ (M / T) × 100 ≦ 50. Image forming method. 29. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a molecular weight integrated value (T) of a region having a molecular weight of 800 or more and a molecular weight of 10
28. The method according to claim 25, wherein the molecular weight integrated value (M) in the region of 000 or more satisfies the following relationship: 15 ≦ (M / T) × 100 ≦ 40. Image forming method. 30. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a top peak height (Ha) and a molecular weight of 2,7 to less than 2,000. 000-300,000
30. The image formation according to claim 25, wherein the height (Hb) of the top peak in the region of (1) satisfies the following relationship: 0.70 ≦ Hb / Ha ≦ 1.30. Method. 31. In the molecular weight distribution of a THF-soluble component of the toner by GPC, the THF-soluble component has a height (Ha) of a top peak and a molecular weight of 2,2 in a region having a molecular weight of 1,000 to less than 2,000. 000-300,000
30. The image forming apparatus according to claim 25, wherein the height (Hb) of the top peak in the region satisfies the following relationship: 0.75 ≦ Hb / Ha ≦ 1.25. Method. 32. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a top peak in a region having a molecular weight of less than 1,000 to 2,000 and a peak having a molecular weight of 2,000 to 300,000. Height of the molecular weight minimum existing between the top peak in the region (H
c) wherein the height (Ha) of the top peak in the region having a molecular weight of 1,000 to less than 2,000 satisfies the following relationship: 0.01 ≦ Hc / Ha ≦ 0.15. Item 32. The image forming method according to any one of Items 25 to 31. 33. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a top peak in a region having a molecular weight of 1,000 to less than 2,000 and a peak having a molecular weight of 2,000 to 300,000. Height of the molecular weight minimum existing between the top peak in the region (H
c) and the height (Ha) of the top peak in a region having a molecular weight of 1,000 to less than 2,000 satisfies the following relationship: 0.01 ≦ Hc / Ha ≦ 0.10. Item 32. The image forming method according to any one of Items 25 to 31. 34. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component is 10% or less.
Weight average molecular weight (M.
34. The method of claim 25, wherein
The image forming method according to any one of the above. 35. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component is 8,2.
35. The image forming method according to claim 25, wherein the image forming method has a number average molecular weight (Mn) of 00 to 700,000. 36. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component is 4 to 1
The image forming method according to any one of claims 25 to 35, having a weight average molecular weight / number average molecular weight (Mw / Mn) of 5. 37. In the molecular weight distribution of the THF-soluble component of the toner by GPC, the THF-soluble component has a weight average molecular weight / number average molecular weight (Mw / Mn) of 3.0 to 3,000 in a molecular weight range of 800 to 3,000. The image forming method according to any one of claims 25 to 36, wherein the value is 0 or less. 38. The toner according to claim 25, wherein the resin component of the toner contains 2 to 30% by weight of a toluene-insoluble component based on the weight of the resin component. Image forming method. 39. The toner according to claim 25, wherein the resin component of the toner contains 3 to 25% by weight of a toluene-insoluble component based on the weight of the resin component. Image forming method. 40. The release agent according to claim 25, wherein the release agent has a wax having a maximum endothermic peak measured by DSC in a range of 40 ° C. to 120 ° C. Image forming method. 41. The method according to claim 25, wherein the release agent has a wax having a maximum endothermic peak measured by DSC in a range of 40 ° C. to 90 ° C. Image forming method. 42. The image according to claim 25, wherein the toner contains 3 to 40 parts by weight of the release agent based on 100 parts by weight of the binder resin. Forming method. 43. The toner according to claim 25, wherein the toner has toner particles having a core / shell structure in which a surface of a core of the release agent is covered with a shell of a shell resin.
43. The image forming method according to any one of the above items. 44. The toner is obtained by polymerizing a polymerizable monomer composition containing at least a polymerizable monomer, a colorant and a release agent in a liquid medium in the presence of a polymerization initiator. 5. The toner according to claim 1, further comprising toner particles.
3. The image forming method according to any one of 3. 45. The toner is obtained by polymerizing a polymerizable monomer composition containing at least a polymerizable monomer, a colorant and a release agent in an aqueous medium in the presence of a polymerization initiator. The image forming method according to any one of claims 25 to 43, comprising toner particles. 46. The toner, comprising: a polymerizable monomer, a colorant,
It has toner particles obtained by polymerizing a polymerizable monomer composition containing at least a release agent and a polar resin in an aqueous medium in the presence of a polymerization initiator. The image forming method according to any one of claims 25 to 43, wherein the image forming method has a core / shell structure in which a core portion surface of the agent is covered with a shell portion of an outer shell resin. 47. The image forming method according to claim 25, wherein the toner is used as a one-component developer. 48. The image forming method according to claim 25, wherein the toner is used as a two-component developer by mixing with carrier particles. 49. The surface of the latent image holding member is charged by applying a charging bias voltage while a contact charging member is in contact with the surface of the latent image holding member. 49. The image forming method according to any one of 25 to 48. 50. A latent image bearing member is an electrophotographic photosensitive member, the photosensitive member surface has a 10 ⁸ to 10 ¹⁵ volume resistivity of the [Omega] cm, and the surface of the photoreceptor, 85 degrees 50. The image forming method according to claim 49, wherein the image has the above contact angle with water. 51. The latent image holding member is a photoconductor for electrophotography, the surface of the photoconductor has a volume resistance value of 10 ⁸ to 10 ¹⁵ Ωcm, and the surface of the photoconductor is 85 ° A dynamic resistance measuring method in which the contact angle with respect to water is greater than that of the contact charging member, and the volume resistance between the voltage applying portion of the contact charging member and the portion in contact with the photoconductor is determined by contacting the charging member with the rotating body of the conductor In | V−VD | / d or |
When the higher electric field of V | / d is defined as V1 (V / cm) (where V is the applied voltage applied to the contact charging member, and VD enters the nip between the photoconductor and the contact charging member). And d is the distance between the voltage applying portion of the contact charging member and the photosensitive member at the time of application, and d is in the range of 10 ⁴ to 10 ¹⁰ Ωcm in the applied electric field range of 20 to V1 (V / cm). The image forming method according to claim 49, wherein: 52. When the applied electric field dependency of the resistance value of the contact charging member, which is higher of | V−VD | / d or | V | / d, is defined as V1 (V / cm), 20 to V1 (V / c
52. The image forming method according to claim 51, wherein in the applied electric field range of m), when a maximum resistance value is R1 and a minimum resistance value is R2, R1 / R2 ≦ 1000. 53. The image forming method according to claim 49, wherein the contact charging agent contains magnetic particles. 54. The image forming method according to claim 53, wherein the magnetic particles used in the contact charging agent have a volume resistance of 10 ⁴ to 10 ⁹ Ωcm. 55. The image forming method according to claim 53, wherein the magnetic particles used for the contact charging agent have an average particle diameter of 5 to 200 μm. 56. The contact charging member has a magnet for holding the magnetic particles, and the magnetic flux density B (T: Tesla) of the magnetic field generated by the magnet, and the maximum of the magnetic particles within the magnetic flux density B The magnetization σ _B (Am ² / kg)
The image forming method according to claim 50, wherein each value is set so as to satisfy the following relational expression B · σ _B ≧ 4. 57. The image according to claim 53, wherein the surface layer of the magnetic particles used in the contact charging agent contains a conductive resin or a conductive particle and a resin. Forming method. 58. A toner comprising a magenta toner having a magenta colorant, a cyan toner having a cyan colorant,
A yellow toner having a yellow colorant and a black toner having a black colorant, and the toner image is
The image forming method according to any one of claims 25 to 57, wherein the image is a full color toner image including the magenta toner, the cyan toner, the yellow toner, and the black toner.