JPH1115189A - Image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming method which is capable of providing high-grade images having excellent fixability and offset resistance stably for a long period in an image forming method using a contact one-component development method. SOLUTION: The wax in the toner particles in the image forming method using the contact one-component development method (a) exhibits the max. endothermic peak in a region of 50 to 130 deg.C at the time of heating up in a DSC curve measured by a differential scanning calorimeter and (b) the total area (S) of the peak detected in a range of 0 to 50 ppm in the spectra measured by a<13> C-NMR(nuclear magnetic resonance) measuring instrument, the total area (S1) of the peak detected in a range of 36 to 42 ppm and the total area (S2) of the peak detected in a range of 10 to 17 ppm satisfy 1.0<=[(S1/S)×100<=10.0, 1.5<=[(2S/S)×100]<=15.0, S1<S2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method used in a recording method utilizing an electrophotographic method, an electrostatic recording method, a magnetic recording method, or the like. More specifically, the present invention relates to an image forming method used in a copying machine, a printer, and a facsimile, which forms a toner image on a photoreceptor in advance and then transfers the image on a transfer material to form an image.

[0002]

2. Description of the Related Art Conventionally, many methods are known as electrophotography. In general, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means. The latent image is developed with a toner to form a visible image, and if necessary, the toner image is transferred to a transfer material such as paper, and then the toner image is fixed on the transfer material by heat, pressure, etc. to obtain a copy. Things. At this time, the toner remaining on the photoreceptor without being transferred to the transfer material after the transfer is cleaned by various methods, and the above-described steps are repeated.

As a method for visualizing an electric latent image, a cascade developing method, a magnetic brush developing method, a non-magnetic one-component developing method, a pressure developing method and the like are known. Further, a magnetic one-component developing method in which a magnetic toner is used, and a rotating sleeve having a magnetic pole disposed at the center is used to fly between the photosensitive member and the sleeve by an electric field is also used.

[0004] In recent years, LED and LBP printers have become the mainstream of printer devices in the market, and the direction of technology has become higher resolution, that is, from 240, 300 dpi to 400, 600, 1200 dpi. ing. Accordingly, higher definition has been required for the developing system. In addition, the functions of the copying machine have been advanced, and the digital copying machine is moving toward digitalization. In this direction, a method of forming an electrostatic charge image with a laser is mainly used, so that the direction is also moving toward a higher resolution, and a high-resolution and high-definition developing method is required similarly to a printer. .

For this reason, the particle size of the toner has been reduced,
JP-A-1-112253, JP-A-1-19115
No. 6, JP-A-2-214156, JP-A-2-214156
284158, JP-A-3-181952,
Japanese Patent Application Laid-Open No. 4-162048 and the like propose a toner having a specific particle size distribution and a small particle size.

In recent years, a so-called contact one-component developing method has been proposed in which development is performed by using a semiconductive developing roller or a developing roller having a dielectric layer formed on its surface to press against a photosensitive member surface layer.

[0007] For example, Japan Hardcopy '
A study of a contact-type one-component non-magnetic developing system has been made on pages 25 to 28 of 89 papers.

[0008] FUJITSU Sci. Tech.
J. , 28,4, pp. 473-480 (Decemb
er 1992) reports an outline of a printer using a one-component contact developing system.

Japanese Patent Application Laid-Open Nos. 5-188765 and 5-187552 disclose techniques relating to a one-component contact developing method.

In the contact one-component developing method, it has been pointed out that the surface of the photoreceptor and the developing electrode are very close to each other, so that the edge effect of development can be reduced.

However, there are disadvantages and limitations in the application range due to the contact between the photosensitive member surface and the toner carrier.

In the one-component developing method, when the photosensitive member and the toner carrier have a certain distance, the lines of electric force concentrate on the edge of the electrostatic latent image on the photosensitive member, and the toner is developed along the lines of electric force. As a result, the quality of the image is likely to be degraded due to the edge effect in which the toner is unbalancedly developed at the edge of the image.

The edge effect is prevented by bringing the photoconductor and the toner carrier very close to each other, but the gap between the photoconductor and the toner carrier is mechanically set, that is, the thickness of the toner layer on the toner carrier is reduced. It is difficult to set the gap smaller than that.

Therefore, the toner carrier is pressed against the photosensitive member to prevent the edge effect. However, if the toner carrier surface moving speed is the same as the photosensitive member surface moving speed, the latent image on the photosensitive member is When the image is visualized, a satisfactory image cannot be obtained. That is, with respect to the photosensitive member surface moving speed,
There is a difference in the moving speed of the toner carrier surface, and a part of the toner on the toner carrier is developed and another part of the toner is peeled off from the latent image on the photoreceptor. A developed image without a faithful edge effect is obtained.

A study of a contact-type one-component non-magnetic developing system has been conducted in Japan Hardcopy '89, pp. 25-28. However, its durability characteristics are not mentioned.

FUJITSU Sci. Tech.
J. , 28,4, pp. 473-480 (Decemb
er 1992) report an outline of a printer using a one-component contact developing method. However, its durability is not sufficient and there is room for further improvement.

Japanese Patent Application Laid-Open Nos. 5-188765 and 5-187552 disclose techniques relating to a one-component contact developing method, but do not disclose techniques for improving durability.

That is, when such a developing method is used,
It is essential that the surface of the photoconductor is rubbed with the toner and the toner carrier, which causes deterioration of the toner due to long-term use, deterioration of the surface of the toner carrier, deterioration of the surface of the photoconductor or abrasion. There was a need for an improved method. Further, for such a reason, there remains an essential problem that it is difficult to increase the speed of the apparatus.

In recent years, from the viewpoint of environmental protection, primary charging and transfer processes using a corona discharge, which has been conventionally used, have been replaced with primary charging using a photosensitive member contact member.
The transfer process is becoming mainstream.

For example, JP-A-63-149669 and JP-A-2-123385 have been proposed. These are related to a contact charging method and a contact transfer method, but a conductive elastic roller is brought into contact with a photoconductor, and the photoconductor is uniformly charged while applying a voltage to the conductive roller. After obtaining the toner image by the development process,
While pressing another conductive roller to which a voltage is applied to the photoconductor, the transfer material is passed through the transfer roller, and the toner image on the photoconductor is transferred to the transfer material, and then a copy image is obtained through a fixing process. .

However, in such a contact transfer method, the transfer member is brought into contact with the photosensitive member via the transfer member at the time of transfer, so that when the toner image formed on the photosensitive member is transferred to the transfer material, The toner images are pressed against each other, causing a problem of partial transfer failure called so-called "missing transfer".

Further, as the diameter of the toner becomes smaller, the adhesion force (mirror image force, van der Waals force, etc.) of the toner particles to the photoreceptor becomes larger than the cloning force applied to the toner particles during transfer. As a result, the transfer residual toner tends to increase.

Accordingly, the toner and the photoreceptor used in such an image forming method have been required to have excellent releasability.

It is known that a wax is contained in a toner as an anti-offset agent. For example, Tokiko Sho 52
The technology is disclosed in JP-3304, JP-B-52-3305, JP-A-57-52574 and the like.

Also, JP-A-3-50559, JP-A-2-79860, JP-A-1-109359, JP-A-62-14166, and JP-A-61-27
3554, JP-A-61-94062, JP-A-61-138259, JP-A-60-25236
No. 1, Japanese Unexamined Patent Publication No. 60-252360, Japanese Unexamined Patent Publication No.
Japanese Patent Application Laid-Open No. 0-217366 discloses a technique for containing a wax.

Waxes are used to improve the toner's anti-offset properties at low and high temperatures and to improve the fixability at low temperatures. Therefore, in the simultaneous cleaning for development, there is a problem that the toner remaining on the transfer easily causes contamination of the charging member, and the amount of waxes added is limited.

Further, a toner produced by a suspension polymerization method has been proposed for a long time (for example, Japanese Patent Publication No. 36-10231). In this suspension polymerization method, a polymerizable monomer and a colorant (and, if necessary, a polymerization initiator, a crosslinking agent, a charge control agent, and other additives) are uniformly dissolved or decomposed to obtain a monomer composition. After that, this monomer composition is dispersed in a continuous layer (for example, an aqueous phase) containing a dispersion stabilizer using a suitable stirrer, and simultaneously undergoes a polymerization reaction, thereby obtaining toner particles having a desired particle size. Is what you get.

In this suspension polymerization method, since a droplet of the monomer composition is formed in a dispersion medium having a high polarity such as water, the component having a polar group contained in the monomer composition is an aqueous phase. A so-called core / shell structure or a sea-island structure can be formed in which a non-polar component is easily present in the surface layer portion, which is an interface with, and non-polar components are not present in the surface layer portion.

By incorporating a wax component, which is a release agent, into a toner by a polymerization method, it has become possible to simultaneously achieve contradictory performances of low-temperature fixing property, blocking resistance and high-temperature offset resistance.

When such a toner is used, there is an advantage that a colorant is hardly exposed to the surface and the like and uniform triboelectricity is obtained. Further, since the classification process can be omitted, the cost reduction effect is large, such as energy saving, time reduction, and improvement in process yield.

However, since the shape of the toner obtained by this method is substantially spherical, the cleaning failure due to the slipping of the toner particles during the cleaning in the above-described electrophotographic process, especially when the blade cleaning is performed. Can occur and can significantly impair the quality of the copy.

In particular, in non-magnetic one-component contact development, the charge amount of the toner developed on the drum is high, and the adhesion force (mirror image force) of the toner particles to the photoreceptor is increased. The toner tends to increase. The charge amount of the transfer residual toner also tends to be high, and the adhesion of the toner particles to the photoreceptor also becomes large, so that there has been a problem that cleaning failure easily occurs during cleaning.

[0033]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to form an electrostatic latent image on a photoreceptor, and in a developing step of the electrostatic latent image, the toner on the photoreceptor and the toner carrier are charged with the photosensitive latent image. Disclosed is a technique for improving toner deterioration in an image forming method using a contact one-component developing method in which a toner carrier is in contact with a photoconductor and the toner carrier is substantially in contact with the photoconductor via toner. It is in.

Another object of the present invention is to disclose a technique for improving the deterioration of the surface of a toner carrier.

Another object of the present invention is to provide an image forming method which does not cause cleaning failure even in blade cleaning.

It is a further object of the present invention to provide an image forming method capable of increasing the speed of the apparatus.

It is a further object of the present invention to provide an image forming method which improves the fixing property and the anti-offset property, and has the durability which realizes a high quality image stably for a long period of time.

Further, an object of the present invention is to provide a charging method using a contact charging member without causing poor charging.
An object of the present invention is to provide an image forming method capable of obtaining a stable image over a long period of time.

[0039]

SUMMARY OF THE INVENTION The present invention provides at least a step of charging an electrostatic latent image carrier; forming an electrostatic latent image on the electrostatic latent image carrier charged by exposure. Developing the electrostatic latent image with a toner carried on the surface of a toner carrier to form a toner image; and transferring the toner image via an intermediate transfer member or without the intermediate transfer member. In an image forming method having a transfer step of transferring to
In the developing step, a toner layer formed by the toner carried on the toner carrier is brought into contact with the surface of the electrostatic latent image carrier,
An electrostatic latent image is developed, and the toner is a toner having toner particles containing at least a binder resin, a colorant, and a wax, and the wax is represented by (a) a DSC curve measured by a differential scanning calorimeter. 50-130 ° C when the temperature rises
(B) ¹³ C-NMR
(Nuclear magnetic resonance) In the spectrum measured by the measuring device, the total area (S) of the peak detected in the range of 0 to 50 ppm, the total area (S1) of the peak detected in the range of 36 to 42 ppm, and The total area (S2) of peaks detected in the range of 10 to 17 ppm is 1.0 ≦ [(S1 / S) × 100] ≦ 10.0 1.5 ≦ [(S2 / S) × 100] ≦ 15. The present invention relates to an image forming method characterized in that the wax satisfies 0 S1 <S2.

According to the present invention, a toner using a wax having specific physical properties as a toner composition is applied to an image forming method including a cleaning step of recovering the transfer residual toner and a contact developing process. In addition, good fixing performance and offset resistance can be achieved at the same time. Further, it is possible to prevent contamination and fusion of the toner on the photoconductor, the charging member, the toner carrier, and the like, and to stably obtain high-quality image.

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As an example of such a developing unit of the present invention, there is a developing unit employing a method in which a toner is coated on the surface of an elastic roller as a one-component developer and is brought into contact with the surface of a photoreceptor. At this time, regardless of whether the toner is magnetic or non-magnetic, it is important that the toner is in contact with the surface of the photoconductor. Further, the toner carrier is substantially in contact with the surface of the photoconductor, which means that the toner carrier is in contact with the photoconductor when the toner is removed from the toner carrier. At this time, in order to obtain an image without an edge effect by an electric field acting between the photoconductor and the elastic roller facing the photoconductor surface via the toner, the surface of the elastic roller or the vicinity of the surface has a potential, and the surface of the photoconductor is It is necessary to have an electric field between the toner carrier and the toner carrier. 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 to provide a thin dielectric layer on the surface layer of the conductive roller. . Further, a configuration in which a conductive layer is provided on a conductive roller on a conductive resin sleeve on which the side facing the photoreceptor surface is coated with an insulating material, or an insulating sleeve on a side not facing the photoreceptor is also possible.

When the one-component contact developing method is used, the peripheral speed of the surface of the roller carrying the toner and that of the photosensitive member may be rotated in the same direction or in the opposite direction. When the rotation is in the same direction, the peripheral speed ratio is preferably 100% or more with respect to the peripheral speed of the photoconductor. If it is less than 100%, problems remain in image quality such as poor line breaks. The higher the peripheral speed ratio, the greater the amount of toner supplied to the development site, the more frequently the toner is attached to and detached from the latent image, and unnecessary portions are scraped off and given to necessary portions. By repeating, an image faithful to the latent image is obtained.

The present invention does not include a two-component developing method using a so-called magnetic brush.

As the cleaning member used in the present invention, a blade, a roller, a fur brush, a magnetic brush or the like can be used. Further, two or more of these cleaning members may be used in combination.

The wax according to the present invention is preferably a substance having a low softening point. According to a DSC curve measured by a differential scanning calorimeter, the wax has a temperature of 50 to 130 ° C., preferably 60 to 130 ° C. when the temperature is raised.
It is characterized by having a maximum endothermic peak in the range of ~ 120 ° C, more preferably 65-100 ° C. By having a maximum endothermic peak in the above temperature range, it greatly contributes to low-temperature fixing, and also effectively expresses releasability. When the maximum endothermic peak is less than 50 ° C., the self-cohesive force of the low softening point substance becomes weak, and as a result, the high-temperature offset resistance deteriorates and the gloss becomes too high. On the other hand, when the maximum endothermic peak exceeds 130 ° C., the fixing temperature increases and it becomes difficult to appropriately smooth the surface of the fixed image. Further, when a toner is directly obtained by a polymerization method by performing granulation and polymerization in an aqueous medium, if the maximum endothermic peak temperature is high, problems such as precipitation of wax during granulation are not preferred.

For measuring the maximum endothermic temperature peak of the wax according to the present invention, for example, a DSC manufactured by Perkin Elmer Co., Ltd.
The measurement is performed by a high-precision internal heating type input compensation type differential scanning calorimeter such as -7.

The measuring method is ASTM D3418-82.
Perform according to. In the present invention, the sample is heated once to obtain a pre-history, then rapidly cooled, and then again at a temperature rate of 10 ° C./mi.
n, a DSC curve measured when the temperature is raised in a temperature range of 0 to 200 ° C. is used.

The measurement of the glass transition point Tg of the toner is performed in the same manner.

On the other hand, in the spectrum of the wax component measured by a ¹³ C-NMR (nuclear magnetic resonance) measuring apparatus, the total area (S) of the signal detected in the range of 0 to 50 ppm and the total area (S) of the signal in the range of 36 to 42 ppm By specifying the relationship between the total area of the detected signal (S1) and the total area of the detected signal (S2) in the range of 10 to 17 ppm, it is possible to impart favorable physical properties to the toner. is there.

The wax used in the present invention has a total area (S) of peaks detected in a range of 0 to 50 ppm in a spectrum measured by a ¹³ C-NMR (nuclear magnetic resonance) measuring apparatus as shown in FIG. ), The total area (S ₁ ) of peaks detected in the range of 36 to 42 ppm and 10 to 17 p
The total area (S ₂ ) of peaks detected in the range of pm satisfies the relations of the equations (1), (2) and (3). S ₁ is derived from tertiary and quaternary carbons present in the wax molecule, which indicates that the wax is not composed of linear polymethylene but has a branched structure. S ₂ is derived from the primary carbon of the methyl group present at the ends of the main and branched chains of the wax molecule.

The wax used in the present invention has a ratio [(S ₁
/ S) × 100] is 1.0 to 10.0, and the ratio [(S
₂ / S) × 100] is 1.5 to 15.0. Preferably, the ratio [(S ₁ / S) × 100] is 1.5 to 8.0, and the ratio [(S ₂ / S) × 100] is 2.0 to 13.0. [(S ₁ / S) × 100] is preferably 2.0 to 6.0, and the ratio [(S ₂ / S) × 100] is preferably 3.0 to 10.0.

When the value of [(S ₁ / S) × 100] corresponding to the abundance ratio of the branched carbon constituting the branched structure is set to 1.0 to 10, the my grade of the wax on the toner surface is appropriately adjusted. To prevent deterioration of the photoconductor, toner carrier and toner due to stress caused by the contact between the toner carrier and the photoconductor in the development process, and to prevent contamination of the photoconductor and toner carrier by the toner at the same time as improving the long-term storage stability of the toner. Thus, an improvement in durability is achieved. That is, it is considered that the wax moderately affects the toner surface, thereby alleviating the stress at the contact portion during development.

Further, by setting the value of [(S ₂ / S) × 100] corresponding to the abundance of the long-chain branched terminal carbon to 1.5 to 15, the balance between the viscosity and the elasticity of the toner at a high temperature can be improved. Because of the optimization, low-temperature fixability is achieved while improving the high-temperature offset resistance and maintaining appropriate gloss.

When [(S ₁ / S) × 100] is less than 1.0 and [(S ₂ / S) × 100] is less than 1.5, it is present in the molecules constituting the wax. When the wax is in a molten state, it means that the molecules constituting the wax are less entangled with each other, thereby reducing the melt viscosity and achieving an improvement in the hot offset resistance. It becomes difficult. In addition, molecules constituting the wax are softened due to less long-chain branching,
Contamination to the contacting members is increased.

[(S ₁ / S) × 100] is equal to 10.
If it exceeds 0 and [(S ₂ / S) × 100] exceeds 15.0, it means that there are many long-chain branches present in molecules constituting the wax, and the melt viscosity of the wax increases. This makes it difficult to achieve an improvement in low-temperature fixability.
Further, if there are many long-chain branches, molecules constituting the wax become hard, so that the surface of the photoreceptor or the toner carrier is damaged or abrasion is promoted, thereby lowering the durability. Further, when the molecules constituting the wax become hard, uniform dispersion becomes difficult, so that the charging becomes uneven and fogging is liable to occur.

The effect of improving the electrophotographic characteristics as described above is as follows.
It is further improved by using a wax having a branched structure developed such that a long branched chain has a further branched short chain. Conventionally, when the branched structure of the wax has been developed, various adverse effects due to dispersibility and the like have been observed, but can be avoided by controlling the branch density and the state of the branched chains as described above. It is to be noted that the use of a mixture of linear waxes within the above range is also a preferred embodiment of the present invention.

In the present invention, ¹³ C-NM of the wax component
The R spectrum is measured under the following conditions.

<Measurement Conditions of ¹³ C-NMR> Apparatus: FT NMR apparatus JNM-EX400 (manufactured by JEOL Ltd.) ¹³ C measurement frequency: 100, 40 MHz Pulse condition: 5.0 μs (45 ° C.) by DEPT method. Data point: 32768 Delay time: 25 sec Frequency range: 10500 Hz Number of integrations: 1000 Measurement temperature: 110 ° C

The measurement sample is prepared as follows. That is, 200 mg of a sample was placed in a 10 mmφ sample tube, and benzene-d6 / o-dichlorobenzene-d4 (1/4) was added as a solvent.
And dissolve it in a thermostat to obtain a measurement solution.

When the wax has a long-chain branched structure, the toner containing the wax improves the low-temperature fixing property and the high-temperature offset resistance, and contaminates members such as an electrostatic latent image carrier and a toner carrier. And at the time of melt-kneading in the production of the toner, it becomes possible to apply a shearing force to the entire composition for producing the toner, so that the dispersibility of each toner constituent material is improved and the developability is improved. . This tendency is more effective when producing a polymerized toner in which a shearing force is hardly applied, and the resulting polymerized toner has good dot reproducibility.

The wax according to the present invention is a low-molecular-weight polyalkylene obtained by radical polymerization of alkylene at high temperature and high pressure or by use of a Ziegler catalyst, and a by-product at this time; A wax obtained from a low-molecular-weight polyalkylene obtained by oxidation of a low-molecular-weight polyalkylene obtained by oxidizing a high-molecular-weight polyalkylene is used.

A wax obtained by separating a wax from these waxes according to their molecular weights using a press sweating method, a solvent method, vacuum distillation, a supercritical gas extraction method, and fractional crystallization (for example, melt liquid crystal precipitation and crystal filtration). Are also preferably used in the present invention. After fractionation, oxidation, block copolymerization, or graft modification may be performed.

The wax having a long-chain branched structure used in the present invention includes, for example, a wax composed of a hydrocarbon compound having a long-chain branched structure represented by the following formula.

[0064]

[Outside 3] (Where A, C, and E represent one or more positive numbers, and B and D
Indicates a positive number. )

The wax is

[0066]

[Outside 4] (Where x represents an integer of 1 or more) and ethylene. The α-monoolefinic hydrocarbon is preferably a mixture having different values of x, and the average value of x is preferably 5 to 30 in order to further improve the low-temperature fixing property and the high-temperature offset resistance of the toner.

The wax having a long-chain branched structure used in the present invention has a weight average molecular weight (Mw) of from 600 to 50,000.
00, more preferably 800 to 40,000, even more preferably 1,000 to 30,000.
Further, the wax having a long-chain branched structure has a number average molecular weight (Mn) of 400 to 4,000, more preferably 450 to 4,000.
3500 is good. The wax having a long-chain branched structure has a Mw / Mn value of 3.5 to 30, more preferably 4 to 30.
~ 25 is good.

When the toner of the present invention is a toner produced by a melt-kneading-pulverization method, the wax is preferably contained in an amount of 1 to 20 parts by weight based on 100 parts by weight of the binder resin.
The amount is more preferably 2 to 17 parts by weight, and still more preferably 3 to 15 parts by weight. It is preferable that the toner contains the wax in the above content because the low-temperature fixability, the blocking resistance, and the offset resistance of the toner are improved, and the amount of free wax particles from the toner particles is reduced.

In the case of a toner produced by a polymerization method, it is preferable that 5 to 20 parts by weight of wax is included in the toner particles per 100 parts by weight of the resin component of the toner particles.

An antioxidant may be added to the wax as long as it does not affect the chargeability of the toner.

The wax having a long-chain branched structure can be used in combination with a wax having a relatively low melting point or a wax having a relatively high melting point.

Preferably, the maximum endothermic peak temperature (W ₁ ° C) of the wax having a long-chain branched structure and the maximum endothermic peak temperature (W ₂ ° C) of the wax used in combination are as follows:

[0073]

[Outside 5] It is better to satisfy the relational expression.

The use ratio of the wax used in combination with the wax having a long-chain branched structure is １ ／ to 9/9 by weight.
1, more preferably 1/3 to 8 /
1, more preferably 1/2 to 7/1. By satisfying the above mixing ratio, the low-temperature fixability and the hot offset resistance of the toner can be further improved without impairing the excellent properties of the wax having a long-chain branched structure.

In the toner of the present invention, a third wax component other than the above wax is used for fine adjustment of low-temperature fixability, anti-blocking property or anti-offset property as long as the effect of the present invention is not impaired. The above can be contained. The content of other waxes is 2
It is preferably 0% by weight or less, and the maximum endothermic peak temperature of the wax is preferably 60 to 140 ° C.

Examples of the combinations of waxes used in the present invention include the following combinations.

(1) Combination of low-melting long-chain branched wax and high-melting long-chain branched wax: The low-melting long-chain branched wax has a maximum endothermic peak temperature of 60 to 80 ° C. and a weight average molecular weight of 700 to 20,000. And Mw / Mn = 4
A value of ~ 15 is good.

The high melting point long chain branched wax has a maximum endothermic peak temperature of 90 to 120 ° C. and a weight average molecular weight of 1,5.
It is preferable that the ratio is Mw / Mn = 5 to 20.

(2) Combination of low-melting long-chain branched wax and high-melting wax: The low-melting long-chain branched wax used in the above (1) is used.

The high melting point wax is a polypropylene wax, an ethylene-propylene copolymer wax, or a wax comprising an alkyl group having a long chain with few branches and having a substituent other than a hydrogen atom at a terminal or in a part of the molecule (substitution). The group is a hydroxyl group and / or a carboxyl group), and the high melting point wax preferably contains at least 50% by weight of an alkyl component having a substituent. The maximum endothermic peak temperature of the high melting point wax is 85 to 150 ° C, the weight average molecular weight is 800 to 15,000, and Mw / Mn
Is preferably 1.5 to 3.

(3) Combination of low-melting wax and high-melting long-chain branched wax: Low-melting wax is a wax having a long-chain alkyl group with little branching. It may have a substituent other than a hydrogen atom at the terminal or in a part of the molecule. When it has a substituent, the substituent is a hydrogen group and / or a carboxyl group, and the wax having an alkyl group having a substituent is preferably contained in the low-melting wax in an amount of 40% by weight or more. Low melting wax has a maximum endothermic peak temperature of 7
It is preferably from 0 to 90C, the weight average molecular weight is from 400 to 700, and the Mw / Mn is from 1.5 to 2.5.

Examples of the low melting point wax include a hydrocarbon wax having a long-chain alkyl group with few branches.
Specifically, it is composed of low molecular weight alkylene polymer wax obtained by radical polymerization of alkylene under high pressure or polymerization under low pressure with Ziegler catalyst; alkylene polymer wax obtained by thermally decomposing high molecular weight alkylene polymer; carbon monoxide and hydrogen Preference is given to synthetic hydrocarbon waxes obtained from the distillation residue of polymethylene hydrocarbons obtained from the synthesis gas by the Age method or by hydrogenating them. Further, those obtained by separating a hydrocarbon wax by use of a press sweating method, a solvent method, vacuum distillation or a separation crystallization method are more preferably used. Examples of the hydrocarbon as a base include polymethylene wax synthesized by a reaction between carbon monoxide and hydrogen using a metal oxide-based catalyst (often a multi-component system of two or more types). Further, there may be mentioned, for example, waxes obtained by the Zintol method, the hydrochol method (using a fluidized catalyst bed), or the Age method (using a fixed catalyst bed), in which a large amount of waxy hydrocarbons is obtained.

The above-mentioned long-chain alkyl group may be partially substituted with a hydroxyl group and a functional group derived from the hydroxyl group (for example, a carboxyl group, an ester group, an ethoxy group, a sulfonyl group, etc.). Long-chain alkyl alcohols are, for example,
It is obtained by the following production method. Ethylene is polymerized using a Ziegler catalyst, and after the polymerization is oxidized, an alkoxide of the catalyst metal and polyethylene is generated. Thereafter, hydrolysis is performed to obtain a long-chain alkyl alcohol.

Examples of the high melting point wax include a hydrocarbon wax having a longer alkyl group with less branching and an ethylene-propylene copolymer. In particular,
For example, low molecular weight alkylene polymer wax obtained by radical polymerization of alkylene under high pressure or Ziegler catalyst under low pressure: alkylene polymer wax obtained by thermally decomposing high molecular weight alkylene polymer: from synthesis gas consisting of carbon monoxide and hydrogen Preference is given to waxes of synthetic hydrocarbons obtained from the distillation residue of polymethylene hydrocarbons obtained by the Age method or by hydrogenating them.

The above-mentioned long-chain alkyl group may be partially substituted with a hydroxyl group and a functional group derived from the hydroxyl group (for example, a carboxyl group, an ester group, an ethoxy group, a sulfonyl group, etc.). ) A copolymer may be formed with acrylic acid (ester) and maleic anhydride.

An antioxidant may be added to the wax in a range that does not affect the charging of the toner.

As the binder resin of the toner used in the present invention, generally used styrene- (meth) acrylic copolymers, polyester resins, epoxy resins and styrene-butadiene copolymers can be used. I can do it. In a method of directly obtaining a toner by a polymerization method, those monomers are preferably used. Specifically, styrene,
styrene-based monomers such as o (m-, p-)-methylstyrene and m (p-)-ethylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, ( Butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth)
(Meth) acrylate monomers such as dimethylaminoethyl acrylate and diethylaminoethyl (meth) acrylate; ene monomers such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile, and acrylamide are preferably used. Can be These can be used alone or generally in the Polymer Handbook, 2nd edition-P13
Monomers are appropriately mixed and used so that the theoretical glass transition temperature (Tg) described in 9 to 192 (manufactured by John Wiley & Sons) indicates 40 to 75 ° C. If the theoretical glass transition temperature is lower than 40 ° C., problems arise in terms of the storage stability of the toner and the durability stability of the developer, while if it exceeds 75 ° C., the fixing point increases.

The molecular weight of the binder resin is measured by GPC (gel permeation chromatography). As a specific GPC measurement method, the toner is extracted in advance with a toluene solvent using a Soxhlet extractor for 20 hours, and then toluene is distilled off with a rotary evaporator. After adding an organic solvent that cannot be dissolved, for example, chloroform, and washing well, the solution dissolved in THF (tetrahydrofuran) was filtered through a solvent-resistant membrane filter having a pore diameter of 0.3 μm. Use
The column configuration is A-801, 802, 803, manufactured by Showa Denko
804, 805, 806, 807 can be connected to measure the molecular weight distribution using a standard polystyrene resin calibration curve. The number average molecular weight (Mn) of the obtained resin component is 5000 to 1
Binder resins having a weight average molecular weight (Mw) and a number average molecular weight (Mn) of 2 to 100 (Mw / Mn) are preferred in the present invention.

In the present invention, a toner having a core / shell structure is preferred. The core / shell structure is a structure in which a core portion composed of a wax component is covered with a shell portion formed of a resin synthesized by polymerization of a polymerizable monomer. Since the toner having the core / shell structure contains a wax component, it is possible to prevent the deterioration of the toner and the contamination of the image forming apparatus. It can be formed over a long period. In addition, the wax acts efficiently at the time of heating, so that the low-temperature fixability and the offset resistance are satisfied.

In the present invention, the core / shell structure can be confirmed by observing the tomographic plane of the toner particles.

As a specific method for measuring the tomographic plane of the toner, a cured product obtained by sufficiently dispersing toner particles in a room-temperature curable epoxy resin and then curing in an atmosphere at a temperature of 40 ° C. for two days is used. After staining with ruthenium tetroxide and, if necessary, osmium tetroxide, a flaky sample is cut out using a microtome with diamond teeth, and the tomographic morphology of the toner is measured using a transmission electron microscope (TEM). . In the present invention, it is preferable to use a ruthenium tetroxide dyeing method in order to give a contrast between materials by utilizing a slight difference in crystallinity between the low softening point substance used and the resin constituting the outer shell. FIG. 2 shows a typical example. In the toner particles obtained in Examples described later, it was observed that the low softening point substance was included in the outer shell resin.

In order to produce a toner having a core / shell structure, a suspension polymerization method described later can be preferably used. In producing toner particles by the suspension polymerization method,
It is particularly preferable to add a polar resin in addition to the outer shell resin containing the wax. As the polar resin used in the present invention, a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, a saturated polyester resin, a polycarbonate, and an epoxy resin are preferably used.

The content of the polar resin in the toner particles is preferably 1 to 20% by weight based on the weight of the toner particles.
More preferably, it is 2 to 16% by weight. When the content of the polar resin is less than 1% by weight, the effect of the addition is not sufficiently exhibited. It is not preferable because the chargeability of the toner under a humid environment is easily reduced.

In the present invention, an outermost resin layer may be further provided on the surface of the toner.

The glass transition temperature of the outermost resin layer is designed to be equal to or higher than the glass transition temperature of the outer resin layer in order to further improve the blocking resistance, and is further crosslinked so as not to impair fixability. Is preferred. The outermost resin layer preferably contains a polar resin and a charge control agent for improving the chargeability.

The method for providing the outermost shell layer is not particularly limited, but includes, for example, the following methods.

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

2. Emulsion polymer particles or soap-free polymer particles composed of monomers containing a polar resin, a charge control agent and a cross-linking agent are added to the reaction system, if necessary, and aggregated on the polymer particles surface, and if necessary, fixed by heat, etc. How to let.

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.

To faithfully develop minute latent image dots for higher image quality, the toner particles have a weight average diameter of 3 μm.
m to 9 μm, preferably 4 μm to 8 μm, and the coefficient of variation in the number distribution is 35% or less, preferably 25%
It is good to be the following. In the toner particles having a weight average diameter of less than 3 μm, a large amount of toner particles remain untransferred on the photoreceptor or the intermediate transfer member due to a decrease in transfer efficiency. Easy to cause. When the weight average diameter of the toner particles exceeds 9 μm, fusion of the surface of the photoreceptor and the intermediate transfer material to the member is likely to occur. When the coefficient of variation in the number distribution of toner particles exceeds 35%, the tendency is further enhanced.

The average particle size and the particle size distribution of the toner were measured using a Coulter Counter TA-II or Coulter Multisizer (manufactured by Coulter), and an interface (manufactured by Nikkaki) for outputting the number distribution and volume distribution, and PC9.
801 personal computer (manufactured by NEC) is connected, and the electrolyte is 1% NaCl using primary sodium chloride.
Prepare an aqueous solution. For example, ISOTON R-II
(Manufactured by Coulter Scientific Japan) can be used. As a measuring method, the electrolytic aqueous solution 100 to 1
0.1 to 5 ml of a surfactant (preferably an alkylbenzene sulfonate) is added as a dispersant in 50 ml,
Further, 2 to 20 mg of measurement data is added. The electrolyte in which the material was suspended was subjected to dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and the volume and number of toner particles of 2 μm or more were measured by using the Coulter Counter TA-II with an aperture of 100 μm. The volume distribution and number distribution were calculated. Then, a volume-based weight average particle diameter (D4) determined from the volume distribution according to the present invention and a number-based number average particle diameter (D1) determined from the number distribution were determined.

The coefficient of variation A in the number distribution of toner particles is calculated from the following equation.

Coefficient of variation = [S / D ₁ ] × 100 where S represents a standard deviation value in the number distribution of toner particles, and D ₁ is a number average particle diameter (μm) of the toner particles.
Is shown).

The toner used in the present invention preferably has a degree of roundness of the toner particles from the viewpoint of improving the fusion of the toner on the toner carrier and the contamination of the surface of the charging member in image formation on a large number of sheets. The value of the shape factor SF-1 is 100 <SF-1 ≦ 160, and the value of the shape factor SF-2 indicating the degree of unevenness of the toner particles is 100 <
SF-2 ≦ 140 is preferable, and more preferably, a toner having a value of SF-1 of 100 <SF-1 ≦ 140 and a value of SF-2 of 100 <SF-2 ≦ 120 is used. It is preferable to improve transferability while maintaining developability.

When the SF-1 exceeds 160, the toner particles are separated from the spherical shape and approach an irregular shape, the toner is easily crushed in the developing device, the particle size distribution fluctuates, the charge amount distribution tends to be broad, and ground fogging and inversion occur. Fog tends to occur. Also, S
When F-2 exceeds 140, the transfer efficiency of the toner image at the time of transfer from the photosensitive member to the transfer material is lowered, and the transfer of characters and line images is undesirably caused.

The toner having a high sphericity as described above is disadvantageous for cleaning in terms of a decrease in scraping property in a cleaning step and an easy passage through a cleaning member. Can also clean toner having a high sphericity as described above, which has been difficult in the past.

In the present invention, the shape factors SF-1, SF
-2 means, for example, FE-SEM (S-80) manufactured by Hitachi, Ltd.
0), 100 toner images of 2 μm or more enlarged 1000 times are sampled at random, and the image information is introduced into, for example, an image analyzer (Luzex III) manufactured by Nicolet and analyzed through an interface. The values calculated from the equations are defined as shape factors SF-1 and SF-2.

[0108]

[Outside 6] (Where MXLNG is the absolute maximum length of the particle, PERI is the perimeter of the particle, and AREA is the projected area of the particle.)

As the colorant used in the present invention, those which are toned to black using carbon black, a magnetic substance, and the following yellow / magenta / cyan colorants as a black colorant are used.

Examples of yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds,
Compounds represented by azo metal complexes, methyl compounds and allylamide compounds are 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 the like are preferably used.

As the magenta coloring agent, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds and perylene compounds are used. Specifically, C.I. I.
Pigment Red 2, 3, 5, 6, 7, 23, 48:
2, 48: 3, 48: 4, 57: 1, 81: 1, 14
4, 146, 166, 169, 177, 184, 18
5, 202, 206, 220, 221 and 254 are preferably used.

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

These colorants can be used alone or as a mixture or in the form of a solid solution. In the case of a color toner, the colorant is selected from the viewpoints of hue angle, saturation, lightness, weather resistance, OHP transparency, and dispersibility in the toner. The colorant is used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the resin.

When a magnetic material is used as the black colorant, unlike the other colorants, 10 to 10 parts by weight of the resin is used.
Used by adding 150 parts by weight. When a magnetic material is used as the black colorant, the shape of the magnetic material may be octahedron, 6
There are a face, a sphere, a needle, a scale, and the like, and an octahedron, a hexahedron, a sphere, an amorphous, and the like having little anisotropy are preferable for increasing the image density. The average particle size of the magnetic material is 0.0
It is preferably 1 to 1.0 μm, more preferably 0.02 μm.
-0.6 [mu] m, and more preferably 0.03-0.4 [mu] m.

The charge control agents used in the present invention include:
A known charge control agent can be used, but a charge control agent having a high charge speed and stably maintaining a constant charge amount is preferable. Further, in the case where a direct polymerization method is used in the present invention, a charge control agent having no polymerization inhibitory property and having no solubilized substance in an aqueous system is particularly preferable. Specific compounds include salicylic acid, naphthoic acid, a metal compound of dicarboxylic acid or a derivative thereof, a metal compound of an azo pigment or a derivative thereof, a sulfonic acid, a polymer compound having a carboxylic acid in a side chain, and a boron compound as a negative compound. , Urea compounds, silicon compounds, curryxarene and the like can be used. As the positive compound, nigrosine, a triphenylmethane compound, a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, an imidazole compound, and the like are preferably used. 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 resin. However, in the present invention, the addition of a charge control agent is not essential. Even when a non-magnetic one-component blade coating developing method is used, the toner is not necessarily charged by positively utilizing the triboelectric charging between the blade member and the sleeve member. It is not necessary to include a control agent.

When a polymerization method is used as the method for producing the toner according to the present invention, for example,
2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,
Azo-based polymerization initiators such as 1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone A peroxide-based polymerization initiator such as peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, and lauroyl peroxide is used.

The amount of the polymerization initiator to be added varies depending on the desired degree of polymerization, but is generally 0.5 to 2 parts by weight per monomer.
0% by weight is used. Although the type of the initiator slightly varies depending on the polymerization method, it is used alone or in combination with reference to the 10-hour half-life temperature.

For controlling the degree of polymerization, known crosslinking agents, chain transfer agents, polymerization inhibitors and the like can be further added and used.

When the suspension polymerization is used as the toner production method according to the present invention, as a dispersant to be used, for example, inorganic oxides such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, and carbonate Examples include calcium, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina, a magnetic material, and ferrite.
As the organic compound, for example, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, starch and the like are used by being dispersed in an aqueous phase. These dispersants are preferably used in an amount of 0.2 to 10.0 parts by weight based on 100 parts by weight of the polymerizable monomer.

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. Can also be used. For example, in the case of tricalcium phosphate, 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. Further, 0.001 to 0.1 part by weight of a surfactant may be used in combination for making these dispersants finer. Specifically, commercially available nonions,
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, calcium oleate and the like are preferably used.

In the case where the suspension polymerization method is used in the toner production method according to the present invention, the toner can be specifically produced by the following production method. A wax, a colorant, a charge control agent, a polymerization initiator, and other additives are added to the monomer, and the monomer composition uniformly dissolved or dispersed by a homogenizer or an ultrasonic disperser is used as a dispersion stabilizer. It is dispersed in the contained aqueous phase by a conventional stirrer, homomixer, homogenizer or the like. Preferably, the stirring speed or time is adjusted so that the droplets of the monomer composition have the desired size of the toner particles, and the granulation is performed. Thereafter, by the action of the dispersion stabilizer, the particles may be stirred to such an extent that the particle state is maintained and the particles are prevented from settling. The polymerization temperature is 40 ° C. or higher, generally 50 to 90 ° C.
The polymerization is carried out at a temperature set to. Further, the temperature may be raised in the second half of the polymerization reaction, and further, for the purpose of improving the durability characteristics in the image forming method of the present invention, the second half of the reaction for removing unreacted polymerizable monomers, by-products, and the like, Alternatively, a part of the aqueous medium may be distilled off 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 3000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer system.

When a toner is produced by the above suspension polymerization method, a toner having a core / shell structure can be obtained by using a monomer having a higher polarity than wax.

Further, in the present invention, by coating the toner surface with inorganic fine powder, the toner particles are provided with appropriate fluidity and chargeability, and at the same time, the cleaning properties are improved and the contact member such as a photosensitive member charging member is provided. It is desirable to adopt a configuration capable of alleviating the stress from the toner, and the coverage of the toner surface is preferably 5 to 99%, more preferably 10 to 99%. Further, by having the inorganic fine powder on the surface of the toner particles, the transfer efficiency is improved and the omission during transfer of characters and line images is improved.

The coverage ratio of the toner surface was determined by using FE manufactured by Hitachi, Ltd.
-Using a SEM (S-800), 100 toner images were randomly sampled, and the image information was introduced into an image analyzer (Luzex3) manufactured by Nicole via an interface, analyzed, and calculated.

Examples of the inorganic fine powder used in the present invention include:
From the viewpoint of durability when added to the toner, it is preferable that the toner particles have an average particle diameter of 1/10 or less. The particle size of the additive means an average particle size obtained by observing the surface of the toner particles with an electron microscope.
As the inorganic fine powder, for example, the following are used. Metal oxides such as aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, tin oxide, zinc oxide; nitrides such as silicon nitride; carbides such as silicon carbide; calcium sulfate, barium sulfate, and carbonate Metal salts such as calcium; fatty acid metal salts such as zinc stearate and calcium stearate; carbon black; silica and the like.

These inorganic fine powders are preferably used in an amount of 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 inorganic fine powders may be used alone or in combination. Those subjected to a hydrophobic treatment are more preferable.

In particular, at least one of them is preferably selected from silica, alumina, titania, and double oxides thereof in order to improve charge stability, developability, fluidity, and storage stability. Furthermore, silica is more preferable. For example, as the silica, both a so-called dry method produced by a vapor phase oxidation of a silicon halide or an alkoxide or a so-called fumed silica and a so-called wet silica produced from an alkoxide water glass can be used. but less silanol groups on the inner surface and the silica fine powder, also Na ₂ O, towards less dry silica of SO ₃ ^2-of such production residue is preferable. In the case of fumed silica, it is also possible to obtain a composite fine powder of silica and another metal oxide by using another metal halide such as aluminum chloride and titanium chloride together with a silicon halide in the manufacturing process. They are also included.

The inorganic fine powder used in the present invention is BET.
The specific surface area by measuring nitrogen adsorption in law 30 m ² / g or more, particularly in the range of 50 to 400 m ² / g give good results. 0.1 to 8 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the toner,
It is particularly preferable to use more than 1.0 part by weight and up to 3.0 parts by weight. In addition, the inorganic fine powder used in the present invention has a silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, a silane coupling agent, and a functional group for the purpose of hydrophobicity and chargeability control, if necessary. It may be treated with a silane coupling agent, a treating agent such as an organosilicon compound or an organotitanium compound, or in combination. In order to maintain a high charge amount and achieve a low consumption and a high transfer rate, it is more preferable that the inorganic fine powder is at least treated with silicone oil.

It is also preferable to add inorganic or organic particles having a primary particle diameter of 50 nm or more (preferably having a specific surface area of less than 30 m ² / g) close to spherical shape to improve transferability and / or cleaning performance. It is one of. For example, spherical silica particles, spherical polymethylsilsesquioxane particles, and spherical resin particles are preferably used.

The toner used in the present invention may further contain other additives within a range that does not substantially adversely affect the toner, for example, lubricant powders such as Teflon powder, zinc stearate powder, polyvinylidene fluoride powder; cerium oxide powder, Abrasives such as silicon carbide powder and strontium titanate powder;
Fluidity-imparting agents such as titanium oxide powder and aluminum oxide powder; anti-caking agents; conductivity-imparting agents such as carbon black powder, zinc oxide powder and tin oxide powder; and improve the developability of organic and inorganic fine particles of opposite polarity. A small amount can be used as an agent.

In order to produce the toner according to the present invention, in addition to the above-mentioned suspension polymerization method, a resin, a wax, a colorant, a charge control agent and the like are uniformly dispersed using a pressure kneader, an extruder or a media disperser. After being dispersed in a toner, the particles are made to collide with a target mechanically or under a jet stream, finely pulverized to a desired toner particle size, and further subjected to a classification process to sharpen the particle size distribution to form a toner, which is a so-called pulverization method. In addition to the production method described in JP-B-56-13945, a method in which a molten mixture is atomized into air using a disk or a multi-fluid nozzle as described in JP-B-56-13945, etc. to obtain a spherical toner, Milk represented by a dispersion polymerization method in which a toner is directly produced using an aqueous organic solvent in which a polymer is insoluble or a soap-free polymerization method in which a polymer is produced directly in the presence of a water-soluble polar polymerization initiator. It is possible to use a polymerization method.

In the present invention, it is preferable that the surface of the photoreceptor is provided with a releasability, and the contact angle of water on the surface of the photoreceptor is preferably 85 degrees or less. More preferably, the contact angle of water on the surface of the photoreceptor is 90 degrees or more. The fact that the surface of the photoreceptor has a high contact angle indicates that the surface of the photoreceptor has high releasability, and this effect can significantly reduce the amount of toner remaining on the transfer, greatly reducing the load on the cleaning process. It is possible to more reliably prevent the occurrence of cleaning failure.

The image forming method of the present invention is particularly effective when a photoreceptor whose surface is mainly composed of a polymer binder is used. For example, when a protective film mainly composed of a resin is provided on an inorganic photoreceptor such as selenium or amorphous silicon, or as a charge transport layer of a function-separated organic photoreceptor, a surface layer composed of a charge transport material and a resin is provided. In some cases, a protective layer as described above may be further provided thereon. As means for imparting releasability to such a surface layer, a resin having a low surface energy is used for the resin constituting the film, additives for imparting water repellency and lipophilicity are added, and high releasability is provided. And dispersing the material having the above into a powder form. Is achieved by introducing a fluorine-containing group, a silicone-containing group, and the like into the structure of the resin. , A surfactant or the like may be added as an additive. As a compound containing a fluorine atom,
That is, it can be achieved by dispersing a compound containing a fluorine atom such as polytetrafluoroethylene, polyvinylidene fluoride, and carbon fluoride.

By these means, the contact angle of water on the surface of the photoreceptor can be made 85 degrees or more. If the contact angle of the photoreceptor surface with water is less than 85 degrees, the toner and the toner carrier are likely to deteriorate due to durability.

Of these, particularly preferred, it is preferred to use a fluorine-containing resin such as polytetrafluoroethylene as a releasing powder and to disperse it in the outermost surface layer of the photoreceptor.

In order to incorporate these powders on the surface, a layer in which the powders are dispersed in a binder resin is provided on the outermost surface of the photoreceptor, or an organic photosensitive resin originally composed mainly of resin is used. In the case of a body, the powder may be dispersed in the outermost surface layer without newly providing a surface layer.

The amount of the powder added to the surface layer is 1 to 60% by weight, and more preferably 2 to 50% by weight, based on the total weight of the surface layer.
Is preferred. When the amount is less than 1% by weight, the residual toner of the transfer is not sufficiently reduced, the cleaning efficiency of the residual toner is not sufficient, and the ghost prevention effect is insufficient. When the amount is more than 60% by weight, the strength of the film is reduced. This is not preferable because the amount of light incident on the photosensitive member is significantly reduced. Also,
Regarding the particle size of the powder, from the viewpoint of image quality, 1 μm or less,
Preferably, it is 0.5 μm or less. If it is larger than 1 μm, the line will be cut poorly due to scattering of incident light, which is not practical.

One preferred embodiment of the photoreceptor used in the present invention will be described below.

Examples of the conductive substrate include metals such as aluminum and stainless steel; plastics having a coating layer made of aluminum alloy, indium oxide-tin oxide alloy; and the like; paper, plastic impregnated with conductive particles, plastic, and conductive polymer. Plastic cylindrical cylinders and films are used.

On these conductive substrates, the adhesion of the photosensitive layer is improved, the coating properties are improved, the substrate is protected, the defect is coated on the substrate,
An undercoat layer may be provided for the purpose of improving the charge injection property from the substrate, protecting the photosensitive layer against electrical destruction, and the like. The undercoat layer is polyvinyl alcohol, poly-N-vinyl imidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, nitrocellulose, ethylene-acrylic acid copolymer, polyvinyl butyral, phenol resin, casein, polyamide, copolymerized nylon, glue,
It is formed by materials such as gelatin, polyurethane, and aluminum oxide. The film thickness is usually 0.1 to 10 μm
m, preferably 0.1 to 3 μm.

It is preferable that a charge generation layer is provided on the undercoat layer. The charge generation layer is made of, for example, azo pigments, phthalocyanine pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, squarylium pigments, pyrylium salts, thiopyrium salts, triphenylmethane pigments, selenium, and amorphous silicon. It is formed by dispersing a charge generating substance in a suitable binder and coating or vapor-depositing. Of these, phthalocyanine pigments are preferred for adjusting the sensitivity of the photoreceptor to a sensitivity suitable for the present invention. As the binder, can be selected from a wide range of binder resins, for example, polycarbonate resin, polyester resin, polyvinyl butyral resin,
Resins such as polystyrene resin, acrylic resin, methacrylic resin, phenolic resin, silicone resin, epoxy resin and vinyl acetate resin are exemplified. The amount of the binder contained in the charge generation layer is 80% by weight or less, preferably 0 to 4%.
It is preferably 0% by weight. Further, the thickness of the charge generation layer is preferably 5 μm or less, particularly preferably 0.05 to 2 μm.

It is preferable that a charge transport layer is laminated on the charge generation layer. The charge transport layer has a function of receiving charge carriers from the charge generation layer in the presence of an electric field and transporting them. The charge transport layer is formed by dissolving a charge transport material in a solvent together with a binder resin as necessary, and applying the solution.
m. As the charge transporting substance, a polycyclic aromatic compound having a structure such as biphenylene, anthracene, pyrene, or phenanthrene in a main chain or a side chain; a nitrogen-containing cyclic compound such as indole, carbazole, oxadiazole, or pyrazoline; a hydrazone compound; Styryl compounds; selenium; selenium-tellurium; amorphous silicon; and cadmium sulfide. Examples of the binder resin for dispersing these charge transporting substances include resins such as polycarbonate resin, polyester resin, polymethacrylate, polystyrene resin, acrylic resin, and polyamide resin, and organic photoconductive resins such as poly-N-vinylcarbazole and polyvinylanthracene. Polymer.

A protective layer may be provided as a surface layer. As the resin of the protective layer, polyester, polycarbonate, acrylic resin, epoxy resin, phenol resin, or a curing agent of these resins is used alone or in combination of two or more.

In addition, conductive fine particles may be dispersed in the resin of the protective layer. Examples of the conductive fine particles include metals and metal oxides. Preferably, there are ultrafine particles such as zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin oxide-coated titanium oxide, tin-coated indium oxide, antimony-coated tin oxide, and zirconium oxide. These may be used alone or as a mixture of two or more. Generally, when particles are dispersed in the protective layer, it is necessary that the particle diameter of the particles is smaller than the wavelength of the incident light in order to prevent scattering of the incident light by the dispersed particles, and the particles are dispersed in the protective layer in the present invention. The particle size of the conductive and insulating particles is preferably 0.5 μm or less. Further, the content in the protective layer is preferably from 2 to 90% by weight, more preferably from 5 to 80% by weight, based on the total weight of the protective layer. The thickness of the protective layer is preferably from 0.1 to 10 μm, more preferably from 1 to 7 μm.

The surface layer can be applied by spray coating, beam coating or permeation (dipping) coating of the resin dispersion.

The condition of the developing step used in the present invention is that the toner layer on the toner carrier is in contact with the surface of the photoreceptor.

In the present invention, a method is also used in which an elastic roller is used as a toner carrier, and a toner layer formed by coating the surface of the elastic roller with toner is brought into contact with the surface of the photoreceptor. At this time, the toner may be either magnetic or non-magnetic, and it is important that the toner layer is in contact with the surface of the photoreceptor. The toner carrier is substantially in contact with the photoconductor surface, which means that the toner carrier is in contact with the photoconductor surface when the toner layer is removed from the toner carrier. At this time, in order to obtain an image without an edge effect by an electric field acting between the photoconductor surface and the elastic roller facing the photoconductor surface via the toner layer, the surface of the elastic roller or the vicinity thereof has a potential. It is necessary to have an electric field between the photoreceptor surface and the toner carrying surface. 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 to provide a thin insulating layer on the surface layer of the conductive roller. . Furthermore, a conductive resin sleeve whose outer surface facing the photoconductor surface of the conductive roller is coated with an insulating substance, or a configuration in which a conductive layer is provided on the inner surface of the insulating sleeve that does not face the photoconductor surface are also possible. It is. It is also possible to use a configuration in which a rigid roller is used as the toner carrier and the photosensitive member is made flexible such as a belt.

The toner carrier according to the present invention is, specifically, a metal core such as aluminum or stainless steel, or a rubber such as silicone rubber or urethane rubber on the surface of a cylindrical sleeve.
It has an elastic layer formed of an elastic material such as an elastomer or a foamed resin.

To the elastic layer of the toner carrier, a resistance adjuster such as carbon black is added for the purpose of imparting charge to the toner, preventing the toner from sticking, and protecting the inside, and the like, or a polyamide resin, a urethane resin, a silicone resin or the like. A coating layer may be provided by a coating agent or a tube. In this case, the electric resistance of the toner carrier is 10 ² to 10 ⁹ Ω.
It is desirable that the adjustment be made so as to fall within the range.

The electrical resistance of the toner carrier is measured by the following method.

That is, as shown in FIG.
The aluminum roller 102 and the developing roller 101 are brought into contact with a contact load of 4.9 N (500 g), and the aluminum roller 102 is rotated at 2 rps. Next, the developing roller 10
1 is applied with a DC voltage of V ₁ = 400V.

A variable resistor R is arranged on the ground side, the voltage V ₂ at both ends is measured while adjusting the resistance value of the variable resistor R according to the developing roller 101, and the current value is calculated. The electric resistance of the toner carrying member 101 was calculated and used as the electric resistance of the toner carrier.

When the one-component contact developing method is used, the surface of the developing roller carrying the toner may be rotated in the same direction as the moving direction of the photosensitive member surface, or may be rotated in the opposite direction. When the rotation is in the same direction, it is desirable that the peripheral speed ratio is higher than 100% with respect to the peripheral speed of the photoconductor.
If it is less than 100%, the image quality is poor. The higher the peripheral speed ratio, the higher. The amount of toner supplied to the development site is large, the frequency of toner detachment from the latent image increases, and unnecessary parts are scraped off and applied to necessary parts repeatedly, so that an image faithful to the latent image is repeated. can get. Specifically, the moving speed of the surface of the toner carrier is preferably 1.05 to 3.0 times the moving speed of the surface of the photoconductor.

Hereinafter, the transfer process applicable to the image forming method of the present invention will be specifically described.

In the transfer step, it is preferable to use a contact transfer method in which a toner image is electrostatically transferred to a transfer material while the transfer means is in contact with the surface of the photosensitive member via the transfer material.
The contact pressure of the transfer means against the photoreceptor surface is preferably at least a linear pressure of 2.9 N / m (3 g / cm), and more preferably 9.8 to 490 N / m (10 to 490 N / m).
(500 g / cm). If the linear pressure as the contact pressure is less than 2.9 N / m (3 g / cm), it is not preferable because the transfer of the transfer material and the occurrence of transfer failure tend to occur. If the contact pressure is too high, the surface of the photoconductor is deteriorated and toner adheres, and as a result, the toner is fused to the surface of the photoconductor.

As the transfer means in the contact transfer step,
An apparatus having a transfer roller or a transfer belt is used. The transfer roller has at least a core metal and a conductive elastic layer covering the core metal, and the conductive elastic layer has a volume resistance of about 10 ⁶ to 10 ¹⁰ Ωcm such as urethane or EPDM in which conductive fine particles such as carbon are dispersed. Made of elastic material.

The present invention is particularly effectively used in an image forming apparatus in which the surface of a photoreceptor is an organic compound. That is, when the organic compound forms the surface layer of the photoreceptor, the transferability is higher because the adhesiveness to the binder resin contained in the toner particles is higher than other photoreceptors using an inorganic material. It has a technical problem that it tends to decrease.
Therefore, the effect of high transferability by the toner used in the present invention becomes more remarkable.

In the present invention, the present invention is particularly effectively used for an image forming apparatus having a small-diameter photosensitive drum having a diameter of 50 mm or less. That is, in the case of a small-diameter photosensitive drum, pressure concentration at the contact portion of the contact member at the same linear pressure is likely to occur. Although it is considered that the same phenomenon occurs in the belt photoconductor, the present invention is also effective for an image forming apparatus using a photoconductor belt having a radius of curvature of 25 mm or less at the contact portion.

Further, in the present invention, it is desirable to control the total charge amount of the toner when developing the toner. Therefore, the surface of the toner carrier according to the present invention is preferably covered with a resin layer in which conductive fine particles and / or a lubricant are dispersed.

As a charging method, a known corona charging method called corotron or scorotron is used, and a method using a pin electrode can also be used. Further, a contact charging method in which a charging member is charged on the surface of the photoreceptor with the ground contacting the same can also be used.

In the present invention, it is particularly effective when the charging means is a contact charging method in which the charging member is brought into contact with the surface of the photosensitive member. That is, compared to non-contact corona discharge in which the charging means does not come into contact with the photoreceptor surface, the contact charging method is liable to cause deterioration of the photoreceptor surface, and from the viewpoint of durability, an increase in untransferred toner due to a decrease in transferability. There is a technical problem that cleaning performance is in a severe direction. Therefore, the effect of the high transferability used in the present invention becomes more remarkable.

As a preferable process condition when a charging roller is used as the contact charging member, the contact pressure of the charging roller is 4.9 to 490 N / m5 to 500 g / cm, more preferably 9.8 to 392 N / m. (10-400g
/ Cm). Further, a DC voltage is preferably applied in order to make the polarity of the transfer residual toner the same as the charge polarity of the photoreceptor and facilitate recovery during development, but an AC voltage is superimposed on the DC voltage. 2 × Vth (V)
It is preferable that an AC voltage having a peak-to-peak voltage less than [Vth; discharge start voltage (V) in DC application] is superimposed on the DC voltage.

Other contact charging members include a method using a charging blade and a method using a conductive brush. These contact charging means have the effects of eliminating the need for high voltage and reducing the generation of ozone.

When the contact charging member is a roller or a blade, a conductive base such as a conductive metal such as iron, copper, or stainless steel; a carbon-dispersed resin; or a metal or metal oxide-dispersed resin is used. In the case of a blade, a rod shape or a plate shape can be used. As the configuration of the elastic roller, a configuration in which an elastic layer, a conductive layer, and a resistance layer are provided on a conductive substrate is used.

As the elastic layer, a sponge made of rubber or rubber such as chloroprene rubber, isoprene rubber, EPDM rubber, polyurethane rubber, epoxy rubber and butyl rubber; styrene-butadiene thermoplastic elastomer, polyurethane thermoplastic elastomer, It can be formed of a thermoplastic elastomer such as a polyester-based thermoplastic elastomer or an ethylene-vinyl acetate thermoplastic elastomer.

The conductive layer preferably has a volume resistivity of 10
⁷ Ω · cm or less, more preferably 10 ¹ to 10 ⁶ Ω · c
m is good. As the conductive layer, for example, a metal deposition film, a conductive particle dispersed resin, a conductive resin, or the like is used. Specific examples include vapor-deposited films of conductive metals such as aluminum, indium, nickel, copper and iron; carbon,
Conductive particle-dispersed resin in which conductive particles such as aluminum, nickel and titanium oxide are dispersed in a resin such as urethane, polyester, vinyl acetate-vinyl chloride copolymer and polymethyl methacrylate; quaternary ammonium salt-containing polymethacrylic acid Examples include conductive resins such as methyl, polyvinylaniline, polyvinylpyrrole, polydiacetylene, and polyethyleneimine.

The resistance layer has a low volume efficiency of 10 ⁶ to 10 ¹² Ω.
・ It is good to be a layer of cm. As the resistance layer, a semiconductive resin or a conductive particle dispersed insulating resin can be used. As the semiconductive resin, for example, ethyl cellulose,
Nitrocellulose, methoxymethylated nylon, ethoxymethylated nylon, copolymerized nylon, polyvinyl hydrin or casein is used. As the conductive particle-dispersed resin, for example, a small amount of conductive particles such as carbon, aluminum, indium oxide, and titanium oxide are dispersed in an insulating resin such as urethane, polyester, vinyl acetate-vinyl chloride copolymer, and polymethyl methacrylate. Dispersed materials may be mentioned.

As the conductive brush as the contact charging member, a brush whose resistance is adjusted by dispersing a conductive material in generally used fibers is used. As the fibers, generally known fibers can be used, and examples thereof include nylon, acrylic, rayon, polycarbonate, and polyester. As the conductive material, generally known conductive materials can be used, for example, conductive metals such as nickel, iron, aluminum, gold and silver; iron oxide, zinc oxide, tin oxide, antimony oxide, and titanium oxide. Oxide of a conductive metal as described above; or a conductive powder such as carbon black. In addition, these conductive materials may be subjected to a surface treatment for the purpose of hydrophobicity and resistance adjustment as required. At the time of use, it is selected and used in consideration of dispersibility with fibers and productivity.

The conductive brush may have a fiber thickness of 1 to 20 denier (fiber diameter of about 10 to 500 μm),
The length of the brush fiber is preferably 1 to 15 mm, and the brush density is preferably 10,000 to 300,000 per square inch (about 1.5 × 10 ^{7 to} 4.5 × 10 ⁸ per square meter). .

In the present invention, it is preferable to have a cleaning step for removing transfer residual toner remaining on the surface of the photoreceptor without being transferred in the transfer step. As a cleaning method, there is a pre-development cleaning method.

In the pre-development cleaning method, the transfer residual toner on the photoreceptor is removed by bringing the cleaning member into contact with the surface of the photoreceptor downstream of the transfer unit and upstream of the charging unit. By providing the cleaning unit on the upstream side of the charging unit, the influence of the transfer residual toner on the charging member can be reduced.

As a cleaning member used in the pre-development cleaning method, a blade, a roller, a fur brush, and a magnetic brush can be used. In addition, two or more of these cleaning members can be used in combination.

However, in the pre-development cleaning method, cleaning is performed by pressing the cleaning member against the surface of the photoconductor, so that the photoconductor is worn and the life of the photoconductor is shortened. However, there is a problem that filming is likely to occur, and a problem of contamination of the cleaning member is easily caused. In addition, among the pre-development cleaning methods, particularly when a spherical toner is applied to a cleaning method using a cleaning blade, the toner passes through the cleaning blade, resulting in a problem of poor cleaning. In the present invention, excellent cleaning properties are obtained by using a toner containing a wax having the above-described characteristics.

Next, the image forming method of the present invention will be specifically described with reference to FIG.

The photoreceptor 36 is charged by the charging roller 31, and after charging, an electrostatic latent image is formed by exposure to a laser beam 40. The electrostatic latent image on the photoreceptor 36 is
4 is developed by the upper toner. Photoconductor 3 after development process
The toner image on 6 is transferred by the transfer roller 37 onto the transferred transfer material 38. After the transfer process, the photoreceptor 36 is charged again by the charging roller 31 after the transfer residual toner is removed by the cleaning member, and the same process is repeated thereafter.

FIG. 5 shows another example of the image forming apparatus capable of smoothly removing the toner that has contributed to the development from the developing sleeve in addition to supplying the toner to the developing sleeve as the toner carrier.

In FIG. 5, reference numeral 1 denotes a photosensitive drum, around which a primary charging roller 2 as contact charging means, a developing device 8 as developing means, a transfer charging roller 21 as contact transfer means, and a register roller 19 are provided. ing. The photosensitive drum 1 is moved by the primary charging roller 2 to, for example, -7.
It is charged to 00V. The applied voltage by the bias applying means 5 is, for example, a DC voltage of -1350V. Then, the photosensitive drum 1 is exposed by irradiating the photosensitive drum 1 with a laser beam 7 by a laser generator 6, and a digital electrostatic latent image is formed. The electrostatic latent image on the photosensitive drum 1 is developed by the developing device 8 with the non-magnetic one-component toner 115 and the transfer agent 20
Bias applying means 2 contacting the photosensitive drum 1 via the
At 4, the image is transferred onto the transfer material 20 by the transfer roller 21 to which the bias voltage is applied. The transfer material 20 on which the toner image 26 has been placed is heated
The toner is conveyed to a heat and pressure fixing device 27 having a pressure roller 29 and is fixed on the transfer material 20.

The charging roller 2 basically has a core 4 in the center and a conductive elastic layer 3 formed on the outer periphery thereof.

As shown in FIGS. 4 and 7, the developing unit 8 contacts the photosensitive drum 1 with the toner layer on the developing or leave 9 as a toner carrier, and applies a bias to the core by a bias applying means 18. A developing sleeve as a toner carrying member including an elastic roller 9 having an elastic layer 11 is provided. A toner application roller 12 having a core metal 13 to which a bias is applied by a bias applying unit 17 and an elastic layer 14 is provided in the developing device 8. A toner regulating blade 16 is provided as a member for regulating the amount of toner attached to and transported to the developing sleeve 9, and the amount of toner (toner layer) transported to the developing area by the contact pressure of the toner regulating blade 16 against the developing sleeve 9. Thickness) is controlled.
In the developing area, at least a DC developing bias is applied to the developing sleeve 9, and the toner layer on the developing sleeve contacts the surface of the photosensitive drum 1, and the photosensitive drum 1 according to the electrostatic latent image.
Transfers upward to form a toner image.

In order to carry out the simultaneous development cleaning, the supply bias voltage applied by the bias applying means 17 is set when the light portion potential of the photosensitive drum 1 is 0 to 250 V and the dark portion potential is 300 to 1000 V. 100
The developing bias voltage applied by the bias applying unit 18 is preferably 100 to 900 V. Further, the supply bias voltage applied by the bias applying means 17 is 10 to 400 in absolute value more than the developing bias voltage applied by the bias applying means 18.
The larger V is preferable because the supply of the nonmagnetic toner 15 to the developing sleeve 9 and the removal of the nonmagnetic toner from the developing sleeve 9 are performed smoothly.

With respect to the rotation direction of the developing sleeve 9, the toner application rollers 12 move their surfaces in the counter direction as shown by the arrows (the rotation direction is the same direction), which indicates that the supply and the stripping of the non-magnetic toner are performed. It is preferred in that respect.

FIG. 4 and FIG. The image forming apparatus adopts an image forming method of a type in which a toner image formed on an image carrier is directly transferred to a recording material without using an intermediate transfer member.

Next, the toner image formed on the image carrier 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 method will be described using the image forming apparatus shown in FIG.

In FIG. 6, a charging roller 52, which is opposed to and rotates in contact with a photosensitive drum 51 serving as an image carrier, provides surface electricity on the photosensitive drum 51, and forms an electrostatic latent image by an exposing means 53. The electrostatic latent image is developed by four color toners of magenta toner, cyan toner, yellow toner, and black toner by developing units 54, 55, 56, and 57 of a one-component contact developing system to form a full-color toner image. At the time of development, each of the developing devices 54, 55,
When one of 56 and 57 moves, the toner carrier of the developing device comes into contact with the surface of the photosensitive drum 51 to perform development. After the development, the developing device moves to the original position again, and The toner carrier is separated from the surface of the body drum 51. This operation is repeated four times for each developing device.

The toner image is transferred to the intermediate transfer member 58 for each color.
The multi-toner image is formed by being transferred onto the top and repeated a plurality of times.

As the intermediate transfer member 58, 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,
What has an elastic layer (for example, nitrile butadiene rubber) in which silicon carbide or titanium oxide is sufficiently dispersed is used. A belt-shaped intermediate transfer member may be used.

The hardness of the intermediate transfer member 58 formed on the surface of the support member 59 is 10 to 50 degrees (JIS K-6301).
In the case of a transfer belt, in the case of a transfer belt to which a transfer material (recording material) is formed, it is preferable that the transfer member is formed of a support member having an elastic layer having this hardness.

In the transfer from the photosensitive drum 51 to the intermediate transfer member 58, a transfer current is obtained by applying a bias from a power source 66 to a metal core 59 as a support member of the intermediate transfer member 58, and the transfer of the toner image is performed. Done. Corona discharge or roller charging from the back side of the holding member or the belt may be used.

The multiple toner images on the intermediate transfer member 58 are collectively transferred onto the recording material S by the transfer means 61. 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 a toner image was
A fixing nip portion between the fixing roller 68 and the pressure roller 69 of the heating and fixing device 70 having a fixing roller 68 as a fixing member having the fixing member 7 therein and a pressure roller 69 pressing the fixing roller 68 is formed. As the S passes, the toner image is fixed on the recording material S.

In FIG. 6, reference numeral 63 denotes a cleaner (first cleaning means) having a cleaning member 62 for removing toner remaining on the surface of the photosensitive drum 51 after the first transfer. Is
It is in contact with the surface of the photosensitive drum 51. 65 is the second
Is a cleaner (second cleaning means) having a cleaning member 64 for removing toner remaining on the surface of the intermediate transfer member 58 after the transfer of the toner image.

[0192]

Hereinafter, the present invention will be described with reference to specific examples, but the present invention is not limited to these examples.

The content of the wax used in the present invention is represented by DS
Table 1 summarizes the measurement results of C and ¹³ c-NMR.

[0194]

[Table 1]

In Table 1, waxes 1 to 6 and comparative waxes 7 to 10 are waxes produced by copolymerizing α-monoolefinic hydrocarbon and ethylene, and comparative wax 1 is a polyethylene wax. Comparative wax 2 is a polypropylene wax, comparative wax 3 is a wax formed of an ethylene-propylene copolymer (copolymerization weight ratio 90:10), and comparative wax 4 is a propylene-ethylene copolymer (copolymer Polymerization weight ratio is 90:10), comparative wax 5 is a paraffin wax, and comparative wax 6 is an ester wax.

[Production Example 1 of Polymerized Toner] 0.1M-ion was added to 710 g of ion-exchanged water in a two-liter four-necked flask.
After adding 450 g of an aqueous solution of Na ₃ PO ₄ and heating to 60 ° C., the mixture was stirred at 12000 rpm using a high-speed stirrer TK homomixer (manufactured by Tokushu Kika Kogyo). This gradually added to 1.0 M-CaCl ₂ aqueous solution 68g to obtain an aqueous medium containing a fine sparingly water-soluble dispersion stabilizer.

On the other hand, as a dispersoid, (monomer) styrene 165 parts by weight 2-ethylhexyl acrylate 35 parts by weight (colorant) carbon black 15 parts by weight (BET specific surface area: 60 m ² / g, oil absorption: 115 ml / 1
(Charge control agent) salicylic acid-based metal compound 2 parts by weight (polar resin) saturated polyester 10 parts by weight (acid value 14, peak molecular weight 7000) (release agent) wax 1 30 parts by weight The above mixture was heated to 60 ° C. After uniformly dissolving and dispersing for 3 hours using an attritor (manufactured by Mitsui Kinzoku), 10 parts by weight of a polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) was dissolved therein. And a polymerizable monomer composition.

The polymerizable monomer composition was put into the aqueous medium, and the mixture was stirred at 12,000 rpm for 10 minutes using a TK homomixer at 60 ° C. in an N ₂ atmosphere. Granulated. Thereafter, the reaction was carried out at the same temperature for 5 hours while stirring with a paddle stirring blade (50 rpm), then the temperature was raised to 80 ° C., and the reaction was carried out for another 5 hours. After completion of the polymerization reaction, the remaining monomer was distilled off under reduced pressure. After cooling, hydrochloric acid was added to remove the dispersion stabilizer, followed by filtration, washing with water, and drying to obtain a sharp black suspension having a weight average diameter of about 6.8 μm. Suspended particles were obtained.

With respect to 100 parts by weight of the obtained particles, BE
2.0 parts by weight of hydrophobic silica having a specific surface area of 140 m ² / g by the T method was externally added to obtain Polymerized Toner 1. Table 2 shows the physical properties of the obtained toner. As shown in FIG. 2A, the wax in the polymerized toner 1 was substantially spherical and dispersed without being compatible with the binder resin.

[Production Examples 2 and 3 of Polymerized Toner] Wax 1
Polymerized toners 2 and 3 were produced in the same manner as in Polymerized toner production example 1 except that waxes 2 and 3 were used instead. Table 2 shows the physical properties of the obtained toner.

[Production Example 4 of Polymerized Toner] The same procedure as in Production Example 1 of the polymerization toner was adopted except that wax 4 was used instead of wax 1 and a metal compound of an azo pigment was used as a charge control agent instead of a metal compound of salicylic acid. Polymerized toner 4 was produced in the same manner. Table 2 shows the physical properties of the obtained toner.

[Production Examples 5 and 6 of Polymerized Toner] 0.1M-
By adjusting the amounts of the aqueous solution of Na ₃ PO _{4 and the} aqueous solution of 1.0 M CaCl ₂ , polymerized toners 5 and 6 were produced in the same manner as in Production Example 4 of polymerized toner. Table 2 shows the physical properties of the obtained toner.

[Comparative Polymerized Toners 1 to 10] Comparative Polymerized Toners 1 to 10 were prepared in the same manner as in Polymerized Toner 4 except that comparative waxes 1 and 2 were used instead of wax 4. did. Table 2 shows the physical properties of the obtained toner.
Shown in

[Production Example 1 of Pulverized Toner] (Resin) 100 parts by weight of styrene-butyl acrylate copolymer (weight average molecular weight: about 300,000, Ta 60 ° C.) (colorant) carbon black (BET specific surface area: 60 m ²⁾
/ G, oil absorption 115ml / 100g) 7.5 parts by weight (charge control agent) salicylic acid-based metal compound 2 parts by weight (release agent) wax 2 3 parts by weight

The above-mentioned materials were previously mixed and melt-kneaded at 130 ° C. by a twin screw extruder. This melt-kneaded material was crushed by a hammer mill to obtain a crushed toner having a 1 mm mesh pass. Further, the crushed product was finely pulverized by a collision type pulverizer using a jet stream, and then subjected to air classification to obtain toner particles having a weight average particle size of 7.2 μm. Based on 100 parts by weight of the obtained particles, the specific surface area by the BET method was 14%.
2.0 parts by weight of hydrophobic silica of 0 m ² / g was externally added,
A pulverized toner 1 was obtained. Table 2 shows the physical properties of the obtained toner. Note that the wax in the pulverized toner 1 is as shown in FIG.
And in a finely dispersed state.

[Preparation Example 2 of Pulverized Toner] A pulverized toner 2 was prepared in the same manner as in Preparation Example 1 of pulverized toner, except that wax 5 was used instead of wax 2. Table 2 shows the physical properties of the obtained toner.

[Production Example 1 of Comparative Pulverized Toner] A comparative pulverized toner 1 was produced in the same manner as in Production Example 1 of the pulverized toner, except that comparative wax 2 was used instead of wax 2. Table 2 shows the physical properties of the obtained toner.

[Comparative Pulverized Toners 2 to 4] [0208] Comparative Pulverized Toners 2 to 4 were prepared in the same manner as Pulverized Toner Production Example 1 except that Comparative Waxes 7 to 9 were used instead of Wax 2, respectively. Was prepared. Table 2 shows the physical properties of the obtained toner.

[0209]

[Table 2]

[Production Example 1 of Photosensitive Drum] As a photosensitive member, an aluminum cylinder having a diameter of 30 mm and a length of 254 mm was used as a base. Produced.

(1) Conductive coating layer: Mainly composed of a powder of tin oxide and titanium oxide dispersed in a phenol resin. The thickness is 15 μm.

(2) Subbing layer: mainly composed of modified nylon and copolymerized nylon. The film thickness is 0.6 μm.

(3) Charge generation layer: mainly composed of an azo pigment having absorption in a long wavelength region dispersed in butyral resin. The film thickness is 0.6 μm.

(4) Charge transporting layer: mainly composed of a hole transporting triphenylamine compound dissolved in a polycarbonate resin (molecular weight 20,000 according to Ostwald viscosity method) at a weight ratio of 8:10, and further comprising polytetrafluoroethylene. Powder (particle size: 0.2 μm) was added at 10% by weight based on the total solid content, and dispersed uniformly. 25 μm thick.

The contact angle of the surface of the obtained photosensitive drum 1 with water was 95 degrees.

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

[Production Example 2 of Photoreceptor Drum] The same procedure as in Production Example 1 of the photoreceptor drum was carried out except that polytetrafluoroethylene powder (particle diameter: 0.2 μm) was not added. A 25 μm charge transport layer was formed, and a photoreceptor drum 2 was produced.

The contact angle of the surface of the obtained photosensitive drum 2 with water was 79 °.

<Embodiment 1> An image forming apparatus used in this embodiment will be described. The image forming apparatus applied to the present embodiment has a configuration as shown in FIG. 5, and is obtained by remodeling a commercially available laser printer LBP-8 Mark IV (manufactured by Canon Inc.) and resetting it.

That is, the surface of the electrostatic latent image carrier 36 is 24 m
It moves in the direction of the arrow at a rotational peripheral speed of m / sec (corresponding to a printout speed of 4 sheets (LTR size) / min). At this time, DC and AC components are applied to the charging roller 31,
The surface of the electrostatic latent image carrier is charged uniformly. Next, the electrostatic latent image carrier is exposed to laser light 40 (600 dpi) to form an electrostatic latent image, an image is formed as a visible image by the toner 30, and then the toner is transferred by the transfer roller 37 to which a voltage 42 is applied. The image is transferred to the transfer material 38.

The developing device of the process cartridge was also modified. That is, instead of an aluminum sleeve containing a magnet serving as a toner supply body, a medium-resistance rubber roller (16 mm in diameter) made of silicone rubber in which carbon black is dispersed and whose resistance is adjusted is used as the toner carrier 34, and an electrostatic latent image carrier is used. 36. The moving direction and the rotational speed of the surface of the toner carrier are the same in the contact portion with the surface of the electrostatic latent image carrier 36, and become 200% of the peripheral speed of the electrostatic latent image carrier. Drive, that is,
The peripheral speed of the toner carrier is 48 mm / sec, and the relative speed with respect to the surface of the electrostatic latent image carrier 36 is 24 mm / s.
ec.

As a means for applying the toner to the toner carrier 34, an application roller 35 was provided at the developing portion and was brought into contact with the toner carrier 34. At the contact portion, the toner 30 was applied onto the toner carrier 34 by rotating the application roller 35 so that the surface of the application roller 35 moved in the opposite direction to the surface of the toner carrier 34. Furthermore, in order to control the coat layer of the toner on the toner carrier,
A resin-coated stainless steel blade 33 was attached. A blade 39 made of urethane rubber was used as a cleaning member for the electrostatic latent image carrier.

As the electrostatic latent image carrier, the photosensitive drum manufactured in Production Example 1 of the photosensitive drum was used, and as the toner, the polymerized toner 1 was used, and the process conditions were set so as to satisfy the following developing conditions. .

Photoconductor dark area potential -700V Photoconductor light area potential -150V Development bias -450V (DC component only)

The toner image transferred onto the transfer material under the above-mentioned image forming conditions was fixed using a hot roll type fixing device having no oil application function.

The set temperature of the fixing device was 130 ° C.

A printout test was performed on 1000 sheets while toner was supplied, and the image was evaluated. The image density, fog suppression and dot reproducibility were all good, and no image fogging, scattering, and cleaning failure occurred. Image quality equivalent to the initial one was obtained. The surface of the photosensitive drum and the surface of the toner carrier were observed, but no replacement was required without fusing.

Table 3 shows the evaluation results.

<Embodiment 2> Embodiment 1 is performed except for the following conditions.
Was performed in the same manner as described above.

The direction of movement of the surface of the toner carrier 34 and the rotational speed thereof are the same at the portion in contact with the electrostatic latent image carrier 36, and are equal to the rotational speed of the electrostatic latent image carrier 36.
Drive is performed so as to be 50%. That is, the peripheral speed of the toner carrier is 60 mm / sec, and the relative speed with respect to the surface of the electrostatic latent image carrier 36 is 36 mm / sec.

As the toner, polymerized toner 2 was used, and process conditions were set so as to satisfy the following developing conditions.

Developing bias -350 V (DC component only) A printout test was performed on 1000 sheets while toner was supplied. Both image density and dot reproducibility were good.
No image fogging, splattering, poor cleaning,
Image quality equivalent to the initial one was obtained. The surface of the photosensitive drum and the surface of the toner carrier were observed, but no replacement was required without fusing. Table 3 shows the evaluation results.

Example 3 Example 1 except for the following conditions.
Was performed in the same manner as described above.

The direction of movement of the surface of the toner carrier 34 and the rotational speed thereof are the same in the contact portion with the electrostatic latent image carrier 36, and are 1 to the rotational speed of the electrostatic latent image carrier 36.
Drive is performed so as to be 50%.

As the electrostatic latent image carrier, the photoreceptor produced in Production Example 2 of the photoreceptor drum was used, the polymerization toner 3 was used as the toner, and the process conditions were set so as to satisfy the following development conditions.

Developing bias -450 V (DC component only)

A printout test was performed on 1,000 sheets while toner was supplied. The image density and dot reproducibility were both good, and no image fogging, scattering, or poor cleaning occurred, and image quality equivalent to the initial level was obtained. Obtained. Further, when the surfaces of the photosensitive drum and the toner carrier were observed, slight fusion was observed on the toner carrier, but the image was not affected and the image had no practical problem. Table 3 shows the evaluation results.

<Examples 4 to 6> The same procedures as in Example 1 were carried out except that polymerized toners 4, 5, and 6 were used. When the toner 5 was used, the reproduction of a latent image of about 50 μm was slightly inferior, but as in Example 1, a good image was obtained through durability. Table 3 shows the results.

<Examples 7 and 8> Operations were performed in the same manner as in Example 1 except that pulverized toners 1 and 2 were used as toners. Although the image density was slightly lowered due to contamination of the toner carrier, there was no practical problem. Table 3 shows the results.

<Comparative Example 1> An experiment was performed in the same manner as in Example 1 except that Comparative Polymerized Toner 1 was used instead of Polymerized Toner 1. The process conditions were set most so as to satisfy the following development conditions.

Developing bias -450 V (only DC component)

When the printout test was started, 10
At the time of 0 sheets, cleaning failure occurred. Then, every time a cleaning failure occurred, the printout test was continued while cleaning the cleaning blade.
At the time of image formation, a white dot image defect due to fusion of the toner on the surface of the photosensitive drum occurred in a part of the solid black image. Then, when the photosensitive drum was replaced, the image defect disappeared, but the image density did not recover to the initial level.

After the printout test of 1,000 sheets is completed,
When a new toner carrier was incorporated and the image density was examined, it was restored to the initial level. When the image density was checked by combining the toner carrier used for 1000 sheets and fresh toner, it was 1.30 and did not recover to the initial level. Table 3 shows the results.

<Comparative Examples 2 to 10> A printout test was performed in the same manner as in Comparative Example 1 except that Comparative Polymerized Toners 2 to 10 were used instead of Comparative Polymerized Toner 1. Table 3 shows the evaluation results.

<Comparative Example 11> A similar test was performed as in Example 1, except that the comparative polymerized toner 2 and the photosensitive drum 2 manufactured in Production Example 2 of the photosensitive drum were used. The process conditions were reset so as to satisfy the following development conditions.

Development bias -350 V (DC component only)

When the printout test was performed, 200
Insufficient cleaning occurred on sheets. Thereafter, every time a defective cleaning occurred, the printout test was continued while cleaning the cleaning blade.
At the time of printing, a white dot-like image defect due to fusion of the toner on the surface of the photosensitive drum occurred in a part of the solid black image.

Then, when the photosensitive drum was replaced, the image defect disappeared, but the image density did not recover to the initial level.

After the completion of the printout test for 1,000 sheets,
When an unused photosensitive drum and toner carrier were incorporated and the image density was examined, it was recovered to the initial level. on the other hand,
When the image density was checked with the combination of the toner carrier used for 1000 sheets and the new toner, the image density was 1.28, and did not recover to the initial level. In addition, the reproduction of the isolated dots was insufficient, and the scattering of the line image was conspicuous. Table 3 shows the results.

<Comparative Example 12> In Example 1, the photosensitive drum 2 manufactured in Production Example 2 of the photosensitive drum was used.
The same print-out test was performed except that the comparative pulverized toner 1 was used as the toner. The image density is 1.
It was as low as 0, and cleaning failure occurred at 100 sheets. Each time a cleaning failure occurred, the printout test was continued while cleaning the cleaning blade. When 200 sheets were printed, a white dot-like image defect due to fusion of toner on the surface of the photosensitive drum to a part of the solid black image was observed. There has occurred.

When the photosensitive drum was replaced, the image defect disappeared, but the image density did not recover to the initial level.

After the printout test for 1000 sheets is completed,
When an unused photosensitive drum and toner carrier were incorporated and the image density was examined, it was recovered to the initial level. One
When the image density was checked with the combination of the toner carrier used for 000 sheets and the new toner, the image density was 1.28, and did not recover to the initial level.

<Comparative Examples 13 to 15> In Example 1,
The same test was performed except that comparative pulverized toners 2 to 4 were used as toners. Table 3 shows the results.

[0254]

[Table 3]

[Production Examples 7-9 of Polymerized Toner] Except that the type of the colorant was changed in place of carbon black, the same procedure as in Production Example 1 of the polymerized toner was carried out.
9 was produced. Table 4 shows the physical properties of the obtained toner.

[Production Examples 5 to 7 of Comparative Pulverized Toner] Comparative pulverized toners 5 to 7 were produced in the same manner as in Production Example 1 of the pulverized toner except that the type of the colorant was changed instead of carbon black. Produced. Table 4 shows the physical properties of the obtained toner.
Shown in

[0257]

[Table 4]

Example 9 An image was formed using an image forming apparatus in which a bias applying means was attached to a toner applying roller of an image forming apparatus having a transfer belt as an intermediate transfer member shown in FIG.

In the image forming apparatus, as a first cleaning means for removing toner remaining on the surface of the electrostatic latent image carrier, a cleaner having a cleaning member in contact with the surface of the electrostatic latent image carrier is provided as a second cleaning means. And a charging unit for charging the electrostatic latent image carrier.
After the transfer step, as a cleaning means for removing the toner remaining on the surface of the intermediate transfer member, a cleaner having a cleaning member in contact with the surface of the intermediate transfer member is used as a cleaning means.
Are provided on the downstream side of the transfer portion and on the upstream side of the first transfer portion.

As the developing device 57, the developing device 8 shown in FIG.
Having the configuration described above. After the first transfer, the toner remaining on the photoreceptor drum surface is made up of only the toner present in the non-image area in the developing unit at the time of development after the charging polarity of the toner is adjusted to a negative polarity by applying a charging bias at the charging unit It was configured to be collected in a developing unit.

In the developing unit 8, a medium-resistance rubber roller (diameter 16 mm) made of silicone rubber in which resistance was adjusted by dispersing carbon black was used as the toner carrier 9, and was brought into contact with the photosensitive drum. Up to the moving direction of the surface of the toner carrier 9, the rotational peripheral speed is the same direction at the portion in contact with the photoreceptor surface, and is driven to be 150% of the rotational peripheral speed of the photoreceptor drum. That is, the peripheral speed of the toner carrier is 1
20 mm / s, and the relative speed to the surface of the photosensitive drum is 40 mm / s.

As a means for applying toner to the toner carrier, a sponge roller having a single layer structure was provided as an application roller 12, and was brought into contact with the toner carrier. In the contact portion, the toner was applied onto the toner carrier by rotating the application roller 12 such that the surface of the application roller 12 moved in a direction opposite to the direction of movement of the toner carrier. further,
A resin-coated stainless steel blade 16 was attached for controlling the toner coat layer on the toner carrier.

As the photosensitive drum, the photosensitive drum 1 manufactured in Production Example 1 of the photosensitive drum is used, the polymerization toner 1 is used as the toner, and the image forming conditions are set so as to satisfy the following developing conditions and transfer conditions. did.

Photoconductor dark area potential: -700 V Photoconductor light area potential: -150 V Development bias applied to toner carrier: -450 V (DC component only) Bias applied to toner application roller: -300 V (DC component only) Transfer bias applied to the intermediate transfer member in the transfer step 1:
300V (DC component only) Transfer bias applied to the transfer roller in the second transfer step: 1000V (DC component only)

The toner image transferred onto the recording material under the above-described image forming conditions was heat-fixed to the transfer material by the following heat fixing device.

As the heat fixing device 70, a heat roll type fixing device having no oil application function was used. At this time, both the upper roller 68 and the lower roller 69 had a surface layer of a fluororesin, and the diameter of the roller was 60 mm. The fixing temperature was set at 150 ° C., and the nip width was set at 7 mm.

Using the image forming apparatus having the above configuration, 10
When a printout test was performed on 00 sheets, a high-density, high-quality image free of image stains was obtained.

The image density, dot reproducibility, and transferability were always good, and image fogging, scattering, image contamination, and poor cleaning hardly occurred. Further, the photoreceptor, the toner carrier, and the intermediate transfer member were observed, but no fusion of the toner occurred.

<Examples 10 to 12> Examples 9 to 12 were repeated except that polymerized toners 7 to 9 were used as toners.
A printout test was performed in the same manner as described above. Table 5 shows the results
As shown in FIG.

<Comparative Examples 16 to 19> A printout test was performed in the same manner as in Example 9 except that Comparative Polymerized Toner 1 and Comparative Pulverized Toners 5 to 7 were used as toners. The results are shown in Table 5.

[0271]

[Table 5]

Example 13 Polymerized Toner 1 as Toner
An attempt was made to form a full-color image in the same manner as in Example 9 except that polymerized toners 7 to 9 were used.
A good full-color image was obtained.

<Comparative Example 20> An attempt was made to form a full-color image in the same manner as in Example 13, except that Comparative Pulverized Toner 1 and Comparative Pulverized Toners 5 to 7 were used as toners. And poor image quality.

<Example 14> Image formation was performed in the same manner as in Example 1 except that a bias voltage (-300 V) was applied to the toner application roller using an image forming apparatus having a configuration as shown in FIG. And a printout test of 2,000 sheets was performed. After completion of the printout, the surface of the toner carrier was observed. As a result, the toner was not fixed, and the toner was successfully peeled off. The obtained image was of high quality.

<Embodiment 14> The cleaner having the first cleaning member, which is the first cleaning means, is removed from the image forming apparatus used in Embodiment 9 and the first transfer is performed by applying a charging bias to the charging section. After uniforming the charge characteristics of the transfer residual toner remaining on the photoreceptor surface to the negative polarity after the process, the developing unit is configured to collect only the toner present in the non-image area in the developing unit in the developing unit, and further to the toner carrier. The applied developing bias was changed to -400V. An image was formed in the same manner as in Example 9 except that the conditions were changed as described above. As a result, the image density, dot reproducibility, and transferability were all good, and image fog, line scattering, and image contamination were observed. And poor cleaning hardly occurred. Further, the photoreceptor, the toner carrier, and the intermediate transfer member were observed, but no fusion of the toner occurred.

<Comparative Example 21> An image was formed in the same manner as in Example 15 except that the comparative pulverized toner 1 was used as a toner. However, contamination of the charging member by the toner was remarkable. Poor charging occurred, and the test had to be stopped halfway.

The evaluation items and the evaluation criteria described in the examples and comparative examples of the present invention will be described.

[Evaluation of Printout Image] (1) Image Density The image density was evaluated based on the image density when a predetermined number of printouts were completed on ordinary paper for copying machines (75 g / m ² ). Note that the image density is "Macbeth reflection densitometer Macbet
hRD918 "(manufactured by Macbeth) was used to measure the relative density of a white background portion with a document density of 0.00 with respect to the printout image.

(2) Fixing Property The fixing property was evaluated by applying a load of 50 g / cm ² , rubbing the fixed image with soft thin paper, and decreasing the image density before and after rubbing (%).

A: Very good (less than 5%) B: Good (5% or more, less than 10%) C: Normal (10% or more, less than 20%) D: Bad (20% or more)

(3) Offset Resistance The offset resistance was evaluated by changing the set temperature of the fixing unit to 180 ° C. and printing out a sample image having an image area ratio of about 5%, based on the degree of stain on the image. .

A: No occurrence B: Almost no occurrence C: Observation with a loupe shows that occurrence is slight D: Offset occurrence is found visually

(4) Scattering A fine line image having a width of 100 μm as shown in FIG.
A line pattern image having alternately non-image portions having a width of 0 μm was printed out, and the state of scattering in the non-image portion between the line images was evaluated.

A: Almost no occurrence B: Slight scattering is observed C: Slight scattering is observed D: Remarkable scattering is observed

(5) Dot Reproducibility The electric field is easily closed by the latent image electric field, and it is difficult to reproduce. An isolated dot pattern having a diameter of 50 μm as shown in FIG.
An image of an isolated dot pattern having a diameter was printed out, and the dot reproducibility was evaluated.

A: Very good (2 or less defects / 100) B: Good (3 to 5/100 defects) C: Normal (6 to 10/100 defects) D: Bad (11 defects) Above / 100)

(6) Image Fogging In printing out a solid white image, the toner on the photosensitive drum before the transfer step after the developing step was peeled off with a transparent adhesive tape, and the toner was uniformly applied on white paper.
The reflection density was measured using a “Macbeth reflection densitometer” (described above), and the amount of toner on the photosensitive drum was evaluated using the difference from the reflection density when only the tape was used. At this time, the smaller this value is, the smaller the amount of toner on the photosensitive drum is, which means that the degree of image fogging is minor.

(7) Transferability In printing out a solid black image, the toner on the photosensitive drum before the cleaning step and after the transfer step was peeled off with a transparent adhesive tape, and the resulting toner was uniformly applied on white paper. The toner amount on the photosensitive drum was evaluated in the same manner as the evaluation of the image fog described above. At this time, the smaller this value is, the smaller the amount of toner on the photosensitive drum is, and the better the transferability is.

(8) Image Stain The image stain due to poor charging appearing on the image at the period of the circumference of the charging roller was visually evaluated.

A: Almost no occurrence B: Slight image dirt is seen C: Some image dirt is seen D: Remarkable image dirt is seen

[Evaluation of Matching of Image Forming Apparatus] (1) Matching with Toner Carrier After the printout test was completed, the state of fixation of the residual toner on the surface of the toner carrier and the effect on the printout image were visually evaluated.

A: No sticking has occurred. B: Hardly sticking has occurred. C: There is sticking, but there is little influence on the image. D: There is much sticking, and image unevenness occurs.

(2) Matching with Photosensitive Drum After the printout test was completed, the occurrence of scratches on the surface of the photosensitive drum and the adhesion of residual toner and the effect on the printout image were visually evaluated.

A: Scratches and sticking are not generated. B: Slight scratches are seen, but there is no effect on the image. C: There is sticking or scratching, but there is little effect on the image. D: Many sticks. Vertical streak image loss

(3) Matching with Intermediate Transfer Body After the completion of the printout test, the surface of the intermediate transfer body and the state of fixation of residual toner were visually evaluated.

A: No scratch and fixation occurred B: The presence of residual toner on the surface was recognized, but no scratch was recognized and there was no effect on the image C: There was fixation or damage but little effect on the image D: Many adhesions cause image loss

[0297]

According to the present invention, the cleaning performance can be improved by applying a toner using a specific wax as a toner composition to an image forming method including a cleaning step of collecting transfer residual toner and a contact developing process. , And both good fixability and offset resistance can be achieved. Further, it is possible to prevent the toner from being contaminated or fused to the photoconductor, the charging member, the toner carrier, and the like, and to stably obtain a high-quality image.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a wax ¹³ C-NMR spectrum according to the present invention.

FIG. 2 is a schematic view showing an example of a cross section of toner particles containing wax.

FIG. 3 is a schematic explanatory view of a measuring device for measuring an electric resistance value of a developing roller.

FIG. 4 is a diagram schematically illustrating an image forming apparatus using a contact one-component developing method.

FIG. 5 is a diagram schematically showing an image forming apparatus used as another example of the image forming method of the present invention.

FIG. 6 is a diagram schematically illustrating an image forming apparatus using an intermediate transfer member.

FIG. 7 is an enlarged view of a developing device.

FIG. 8 is an explanatory diagram of a line document for evaluating scattering.

FIG. 9 is an explanatory diagram of an isolated dot pattern for evaluating dot reproducibility.

[Explanation of symbols]

 Reference Signs List 1 photosensitive drum 8 developing device 9 developing sleeve 10 core metal 11 elastic layer 12 toner application roller 13 core metal 14 elastic layer 15 toner 16 toner regulating blade 31 charging roller 34 toner carrier 36 photoconductor 37 transfer roller 38 transfer material 40 laser light Reference Signs List 51 photoconductor drum 52 charging roller 53 exposing means 54, 55, 56.57 developing device 58 intermediate transfer member 59 support member 60 elastic layer 62, 64 cleaning member 63, 65 cleaner 66 power supply 67 heating element 68 fixing roller 69 pressure roller 70 Heat Fixing Device 101 Developing Roller 102 Aluminum Roller

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03G 15/02 102 G03G 15/08 507L 15/06 101 15/16 103 15/08 507 9/08 361 15/16 103 371 21 / 10 374 384 21/00 310 (72) Inventor Satoshi Handa 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Yasawa Aya 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (44)

[Claims] An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier charged by exposure; and charging the electrostatic latent image. Developing with a toner carried on the surface of the toner carrier to form a toner image; image forming having a transfer step of transferring the toner image to a transfer material with or without an intermediate transfer member In the method, in a developing step, a toner layer formed by the toner carried on the toner carrier is brought into contact with the surface of the electrostatic latent image carrier,
Developing an electrostatic latent image, wherein the toner is a toner having toner particles containing at least a binder resin, a colorant, and a wax; and the wax is (a) a DSC curve measured by a differential scanning calorimeter. Shows a maximum endothermic peak in the range of 50 to 130 ° C. when the temperature is raised, and (b) a total of peaks detected in a range of 0 to 50 ppm in a spectrum measured by a ¹³ C-NMR (nuclear magnetic resonance) measuring apparatus. Area (S), total area of peaks detected in the range of 36 to 42 ppm (S1), and 10 to 1
The total area (S2) of peaks detected in a range of 7 ppm is 1.0 ≦ [(S1 / S) × 100] ≦ 10.0 1.5 ≦ [(S2 / S) × 100] ≦ 15.0 S1 <An image forming method, characterized in that the wax satisfies S2. 2. The image forming method according to claim 1, wherein the toner has an inorganic fine powder. 3. The inorganic fine powder comprises an inorganic compound selected from the group consisting of silica, alumina, titania, and a double oxide thereof.
2. The image forming method according to 1., 4. A spectrum of the wax measured by a ¹³ C-NMR (nuclear magnetic resonance) measuring apparatus, wherein 1
4. The image forming method according to claim 1, wherein a plurality of peaks are detected in a range of 0 to 17 ppm. 5. A weight average molecular weight (Mw) of the wax.
The image forming method according to any one of claims 1 to 4, wherein the number is 600 to 50,000. 6. A weight average molecular weight (Mw) of the wax.
The image forming method according to any one of claims 1 to 4, wherein the number is 800 to 40,000. 7. A weight average molecular weight (Mw) of the wax.
The image forming method according to any one of claims 1 to 4, wherein the number is from 1,000 to 30,000. 8. The number average molecular weight (Mn) of the wax
The image forming method according to any one of claims 1 to 7, wherein the number is from 400 to 4,000. 9. A number average molecular weight (Mn) of the wax.
The image forming method according to any one of claims 1 to 7, wherein the number is 450 to 3,500. 10. The weight average molecular weight (Mw) of the wax.
And the number average molecular weight (Mn), Mw / Mn, is 3.5.
The image forming method according to any one of claims 1 to 9, wherein 11. A weight average molecular weight (Mw) of the wax.
And the number average molecular weight (Mn) Mw / Mn is 4.0 to 4.0.
The image forming method according to claim 1, wherein the number is 25. 12. In the spectrum of the wax measured by a ¹³ C-NMR (nuclear magnetic resonance) measuring apparatus, 0%
Total area of peaks detected in the range of 50 ppm (S), total area of peaks detected in the range of 36 to 42 ppm (S1), and total area of peaks detected in the range of 10 to 17 ppm (S2) Is a wax satisfying 1.5 ≦ [(S1 / S) × 100] ≦ 8.0 2.0 ≦ [(S2 / S) × 100] ≦ 13.0. 12. The image forming method according to any one of 11. 13. The spectrum of the wax measured by a ¹³ C-NMR (nuclear magnetic resonance) measuring apparatus,
The total area (S) of peaks detected in the range of 〜50 ppm, the total area of peaks detected in the range of 36 to 42 ppm (S1), and the total area of peaks detected in the range of 10 to 17 ppm (S2) 2) is a wax which satisfies 2.0 ≦ [(S1 / S) × 100] ≦ 6.0 3.0 ≦ [(S2 / S) × 100] ≦ 10.0. 12. The image forming method according to any one of claims 1 to 11. 14. The wax has a DSC curve
14. The image forming method according to claim 1, wherein the image forming method has a maximum endothermic peak at 60 to 120 [deg.] C. when the temperature is raised. 15. The wax has a DSC curve
The image forming method according to claim 1, wherein the image forming method has a maximum endothermic peak at 65 to 100 ° C. when the temperature is raised. 16. The wax represented by the following formula: (Where A, C and E each represent an integer of 1 or more; B and D
Represents an integer. 16. The image forming method according to claim 1, wherein the wax is a wax having a branched structure represented by the following formula: 17. The wax of the formula The image according to any one of claims 1 to 16, wherein the image is a copolymer of α-monoolefinic hydrocarbon and ethylene represented by the formula (where x represents an integer of 1 or more). Forming method. 18. The wax, wherein the average value of x is 5 to 3
18. The image forming method according to claim 17, wherein the image forming method is a copolymer of α-monoolefinic hydrocarbon of 0 and ethylene. 19. In a transmission electron microscope (TEM) for observing a tomographic plane of the toner particles, the wax is dispersed in a substantially spherical and / or spindle-shaped island shape without being compatible with the binder resin. The image forming method according to claim 1, wherein: 20. The toner particles having a weight average particle size of 3 to
The image forming method according to claim 1, wherein the thickness is 9 μm. 21. The toner particles having a weight average particle size of 4 to
The image forming method according to claim 1, wherein the thickness is 8 μm. 22. The toner particles, wherein the value of the shape factor SF-1 is 100 <SF-1 ≦ 160, and the shape factor S
22. The image forming method according to claim 1, wherein the value of F-2 satisfies 100 <SF-2 ≦ 140. 23. The toner particles, wherein the value of the shape factor SF-1 is 100 <SF-1 ≦ 140, and the shape factor S
22. The image forming method according to claim 1, wherein the value of F-2 is 100 <SF-2 ≦ 120. 24. The method according to claim 1, wherein the toner particles are toner particles produced by a polymerization method.
3. The image forming method according to any one of 3. 25. The image forming method according to claim 1, wherein the toner particles have a core / shell structure. 26. The image forming method according to claim 25, wherein in a toner particle having a core / shell structure, a main component of a core portion is wax, and the melting point of the wax is 40 to 90 ° C. 27. The method according to claim 1, further comprising a cleaning step for collecting toner remaining on the surface of the electrostatic latent image carrier after the transfer step. Image forming method. 28. A pre-development cleaning method in which the cleaning step is performed after the transfer step and before the charging step, in which the surface of the electrostatic latent image carrier is cleaned by a cleaning member in contact with the surface of the electrostatic latent image carrier. 28. The image forming method according to claim 27, wherein: 29. The electrostatic latent image carrier according to claim 1, wherein the surface of the photosensitive member has a contact angle with water of 85 degrees or more. An image forming method according to any one of the above. 30. The electrostatic latent image carrier according to claim 1, wherein the surface of the photosensitive body has a contact angle with water of 90 degrees or more. 2. The image forming method according to 1., 31. The electrostatic latent image carrier according to claim 1, having a surface layer in which a compound powder containing a fluorine atom is dispersed in a resin. The image forming method as described in the above. 32. In the developing step, the moving direction of the surface of the toner carrier in the developing area is set to the same direction as the moving direction of the surface of the electrostatic latent image carrier. 31. The image forming method according to any one of items 31. 33. In the developing step, the moving speed of the surface of the toner carrier in the developing area is set to be 1.05 to 3.0 times the moving speed of the surface of the electrostatic latent image carrier. 33. The image forming method according to claim 32, wherein: 34. In the developing step, a toner layer having a regulated toner layer thickness is formed on the surface of the toner carrier by bringing a toner layer thickness regulating member into contact with the toner carried on the toner carrier. The image forming method according to any one of claims 1 to 33, wherein: 35. The toner held in a developing device, and the toner held in the developing device is supplied to the toner carrier by a toner supply member for supplying the toner to the toner carrier. 2. The method according to claim 1, wherein the supply is performed.
35. The image forming method according to any one of items 34 to 34. 36. The toner supply member comprises a coating roller abutting on the surface of the toner carrier, and the direction of movement of the surface of the toner coating roller is opposite to the direction of movement of the surface of the toner carrier. The image forming method according to claim 35, wherein the setting is set. 37. A developing bias voltage is applied to the toner carrier during development of the electrostatic latent image, and a coating bias voltage is applied to the toner applying roller when supplying toner to the toner carrier. 37. The image forming method according to claim 36, wherein is applied. 38. An application bias voltage applied to the toner application roller is set to be higher in absolute value than a development bias voltage applied to the toner carrier, and the toner application roller is 38. The image forming method according to claim 37, wherein the toner is supplied to the surface of the body, and the toner remaining on the surface of the toner carrier after development is peeled off. 39. The electrostatic latent image on the electrostatic latent image carrier has a light portion potential having an absolute value of 0 to 250 V, a dark portion potential having an absolute value of 300 to 1000 V, and applying the toner. The coating bias voltage applied to the roller is 100 to 900 V in absolute value
The developing bias voltage applied to the toner carrier has an absolute value of 100 to 900 V, and the coating bias voltage is 10 to 400 V in absolute value than the developing bias voltage.
38. The method according to claim 37, wherein the toner application roller is configured to supply the toner to the surface of the toner carrier and to remove the toner remaining on the surface of the toner carrier after the development. The image forming method as described in the above. 40. In the transfer step, a transfer member to which a voltage is externally applied is brought into contact with the electrostatic latent image carrier through the transfer material, thereby forming the image on the electrostatic latent image carrier. 40. The image forming method according to claim 1, wherein the transferred toner image is transferred to the transfer material. 41. The method according to claim 1, wherein in the transfer step, a recording material is used as the transfer material, and the toner image transferred to the recording material is fixed on the recording material. The image forming method as described in the above. 42. In the charging step, the electrostatic latent image carrier is charged by bringing a charging member to which a voltage is applied from the outside into contact with the electrostatic latent image carrier. The image forming method according to any one of claims 1 to 41. 43. The image forming method according to claim 1, wherein in the charging step, a DC voltage is externally applied to the charging member. 44. The charging device according to claim 1, wherein in the charging step, a DC voltage and an AC voltage that is less than twice the discharge starting voltage when the DC voltage is applied are externally applied to the charging member. 2. The image forming method according to 1.,