JP2003207923A - Image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming method capable of forming images of high resolution and high fineness. <P>SOLUTION: The image forming method has (a) an electrostatic charging process step; (b) an exposing process step; (d) a developing process step; (4) a transferring process step; and (e) a cleaning process step, in which toners contain at least a binder resin, coloring agents, wax component, and oxycarboxylic acid and the mass A (mg) of the oxycarboxylic acid extracted by methanol from 1 g toners and the mass B (mg) of the oxycarboxylic acid extracted by 0.1 mol/L aqueous sodium hydroxide solution satify A/B=1.05 to 3.00, B=0.10 to 3.50 mg (based on the mass of the toners). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method used in a recording method using an electrophotographic method, an electrostatic recording method, an electrostatic printing method or the like. More specifically, the present invention relates to an image forming method used in an image recording apparatus that can be used in a copying machine, a printer, a facsimile, a plotter and the like.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic method, U.S. Pat. No. 2,297,691 and JP-B-42-23910 are known.
Many methods are known as described in Japanese Patent Publication No. 43-24748 and Japanese Patent Publication No. 43-24748. Generally, a photoconductive substance is used to form an electrostatic latent image on a photoconductor by various means, and then the electrostatic latent image is developed with a toner, and if necessary, a transfer material such as paper is transferred. After the toner image is transferred with or without the intermediate transfer member, the toner image is fixed by heat, pressure, heat and pressure, solvent vapor, or the like to obtain a fixed image. In addition, when there is a step of transferring the toner image, a step for removing the transfer residual toner on the photoconductor is usually provided.

A developing device for developing an electrostatic latent image with toner is equipped with a toner carrier (hereinafter also referred to as a developing roller) attached to a developing container, and this developing roller serves as a developing section. As a means for regulating the thickness of the thin toner layer carried and conveyed, a toner regulating member (hereinafter also referred to as an elastic blade) is brought into contact with the developing roller, and the toner is brought into contact with the toner regulating member and the toner carrier. A thin layer of toner is formed on the toner carrier by controlling the toner to pass therethrough, and a frictional charge for developing an electrostatic latent image is applied to the toner by friction at the contact portion. Has been.

As the toner regulating member as described above, there are a rubber plate, a metal thin plate and the like, as well as a resin thin plate or a laminate of these, for example, a positively chargeable toner is made of a metal thin plate as a supporting layer. A laminate of a charge-imparting layer such as a charge-controlled silicone rubber, and a negatively-charged toner containing a magnetic material are thin plates of urethane rubber subjected to a charge-control treatment.

In recent years, in printers and facsimiles, the size and color of the image forming apparatus have been remarkably reduced, and various developing devices using one-component non-magnetic toner have been proposed and put into practical use. There is an increasing demand for high resolution for these image forming apparatuses. For example, initially, 200 to 300 d is required.
The resolution that was pi (dot per inch) is 4
It is about 00 to 1200 dpi, further 2400 dpi. Further, with regard to copying machines as well, digitalization has made them highly functional, and there is also a strong demand for developing methods capable of achieving high-resolution and high-definition image formation.

Under such circumstances, it is indispensable to develop a technology for forming a thin layer of toner on a toner carrier, and some measures have been proposed so far.

For example, in Japanese Patent Publication No. 51-36070, a method of contacting a toner regulating member with a toner carrier to sequentially charge the toner, and in Japanese Unexamined Patent Publication No. 62-99772, the material of the toner carrier is specified. It has been proposed to use a material farther in the triboelectric series from the constituent material of the toner. However, although these methods can increase the triboelectric charge amount of the toner to some extent, they have a problem that the toner charge state becomes nonuniform when the toner layer thickness is uneven.

By the way, in order to achieve high-resolution and high-definition image formation, the particle size of the toner is reduced, and at the same time, low-temperature fixing is required in order to save energy. In such a case, it is becoming more difficult to uniformly form the thin layer of toner as described above on the toner carrier, and when the developing operation is repeated many times, the material and structure of the toner regulating member are increased. Therefore, the following problems are likely to occur.

That is, as the toner regulating member, (1) SU
When an elastic blade made of a metal thin plate such as S or phosphor bronze is used, the hardness of the metal thin plate is too high and the contact state in the longitudinal direction is likely to be non-uniform, resulting in a thin toner layer formed on the toner carrier. This causes unevenness in the layer thickness. Further, since excessive force is easily applied to the toner and the releasability of the metal thin plate surface is low, toner fusion occurs at the contact portion between the metal thin plate surface and the toner carrier, causing image defects such as image streaks. I will leave. In this case, it is possible to avoid the toner fusion by reducing the contact pressure between the metal thin plate and the toner carrier, but the unevenness of the toner thin layer and the insufficient triboelectric charge amount as described above. Cause (2) When using a conventional elastic blade made of urethane rubber or silicone rubber in the form of a plate or an elastic blade obtained by adhesively molding these rubber plates on a thin metal plate in order to obtain a stable contact state over time, Although the problem (1) can be prevented to some extent, the ability to impart triboelectric charge to the toner becomes insufficient, causing image fog. Also, unlike magnetic toners that can enjoy a magnetic binding force, non-magnetic toners used for color images and the like must electrostatically adhere to the developing sleeve by the toner itself obtaining a high frictional charge. When the amount is reduced, the toner is scattered from the toner carrier, which causes a problem of contaminating the inside of the image forming apparatus.

Therefore, it is necessary to use a material having a high triboelectric charge imparting ability as the material used for the elastic blade, a material having a high electron accepting property for the positive charging toner and an electron receiving property for the negative charging toner. It is necessary to select a highly donating material. However, in this case, a new problem arises in that the triboelectric charging to the toner is easily affected by the use environment. In particular, for negatively chargeable toner, if a material containing a charge control agent having a high electron donating property in a base material such as silicone rubber or urethane rubber is used, the toner is excessively charged in a low temperature and low humidity environment and the developing sleeve As a result, the developing efficiency is lowered and the image density is lowered. Further, in a high temperature and high humidity environment, triboelectrification is insufficiently applied, so that image fog occurs.

On the other hand, it is also known to select a material having a high electron donating property, such as a polyamide resin typified by nylon, for the toner regulating member for the purpose of sufficiently imparting triboelectric charge to the toner. However, since these polyamide resins do not have elasticity, it is difficult to use a plate-shaped molded product as it is as a toner regulating member in terms of maintaining a uniform contact state with the toner carrier. . Therefore, in order to control the contact pressure to the toner carrier, a thin metal plate is used as a support layer, and the thin metal plate is coated with a polyamide resin, or a plate-shaped product is used for adhesion. Although it has been possible to improve the charge imparting ability to toner to some extent, it becomes difficult to form a uniform thin toner layer on the developing sleeve as in the case of using a thin metal plate alone, and Toner fusion may occur due to repeated operations. These causes are, of course, caused by excessive force applied to the toner particles when the toner particles pass through the toner regulating member because the hardness of the polyamide resin is too high.

From the above, for the purpose of reducing the hardness of the elastic blade, for example, a urethane rubber is adhered to a thin metal plate as an elastic layer, and the surface thereof is coated with the above polyamide resin thinly to form a three-layer structure. Even in such a case, it has been very difficult to solve the conventional problems such as imparting triboelectric charge to the toner, forming the toner layer uniformly on the toner carrier, and preventing toner fusion. In other words, the characteristics required of the elastic blade as the toner regulating member are excellent in imparting triboelectric charging to the toner, and have appropriate hardness, so that the toner can be applied without applying excessive force to the toner at the contact portion. The above-mentioned conventional materials and constitutions did not sufficiently satisfy these characteristics, so that image fog and toner fusion could not be prevented.

Therefore, the applicant of the present invention has filed Japanese Patent Application Laid-Open No. 9-5018.
Japanese Unexamined Patent Application Publication No. 5 and No. 319213, and Japanese Patent Laid-Open No. 10-3
In JP-A-074733, a polyamide resin or a polyamide-containing elastomer containing a polyamide component having good charge imparting ability and a polyether component having elasticity is used with a toner regulating member having an appropriate hardness. By having sufficient triboelectrification ability to the electrostatically charged toner, image fogging is prevented even under high humidity, and image unevenness and image streaks due to toner fusion which occur when the developing operation is repeated even under high temperature. It was proposed to prevent the occurrence of such a phenomenon and to stably form a good toner thin layer on the toner carrier.

However, an elastic blade prepared by preparing a polyamide resin or polyamide elastomer containing a polyamide component having a good triboelectric charging ability and a polyether component having elasticity to have a specific Shore D hardness is provided on a toner carrier. Although it forms a good thin layer of toner, there is room for improvement when the non-magnetic one-component toner for the purpose of reducing the particle size and fixing at low temperature as described above is used in the developing device adopting the contact developing method. Turned out to be.
In particular, it is required to reduce image deterioration and stably perform high-resolution and high-definition image formation even under severe use conditions such as restarting use after being left in a high temperature and high humidity environment for a long time. .

The contact developing system is a developing system in which a toner image formed by directly contacting a thin layer of toner formed on the surface of a toner carrying member with an electrostatic latent image carrying member is achieved, and image reproducibility is further improved. It attracts attention as a developing method. It is also possible to eliminate the AC component from the developing bias applied to the toner carrier at the time of development and simplify it to only the DC component. However, unlike the jumping method in which development is carried out by non-contact, a thin layer of toner is always in contact with the electrostatic latent image carrier, so image fog is likely to occur.
If the process speed during image formation increases,
There is a potential problem that deterioration of the image is caused by acceleration of surface deterioration of the toner particles and poor charging of the toner due to frictional charging with the electrostatic latent image carrier. These problems are likely to occur when a non-magnetic one-component toner having a fine particle size and low temperature fixing is used, and particularly when the AC component is removed from the developing bias and only the DC component is used, the toner in the developing section is not used. It becomes visible because the stirring effect of is lost.

On the other hand, in response to the demand for a developing method capable of achieving high-resolution and high-definition image formation, Japanese Patent Laid-Open No. 112253 / 1-11253.
Japanese Patent Laid-Open No. 1-191156, Japanese Patent Laid-Open No. 2-2
No. 14156, Japanese Patent Application Laid-Open No. 3-181952, Japanese Patent Application Laid-Open No. 4-162048, etc. propose a small particle size toner exhibiting a specific particle size distribution, and more uniform pressure contact with a toner carrier is required. However, the conventional elastic blade has a limitation in forming a uniform thin layer of toner. Also,
As described in JP-A-2-284154, since fine powder particles having a relatively small particle size in a toner have a relatively large triboelectric charge amount, they are strongly reflected on the surface of the toner carrier due to their strong mirroring force. Since the toner fine powder particle layer is formed by adhering to the toner, it is difficult to uniformly apply triboelectric charge to the toner. These problems also tend to occur when the AC component is eliminated from the developing bias.

By the way, in this technical field, as a method for cleaning and removing the transfer residual toner remaining on the image carrier, there are a blade cleaning method using an elastic body such as urethane rubber, a fur brush cleaning method and a roller cleaning method. These methods are widely practiced, and all of these methods bring a cleaning member into contact with the surface of an image bearing member such as a photosensitive drum to mechanically collect the transfer residual toner into a waste toner container. However, there are problems caused by the cleaning member being strongly pressed against the surface of the photoconductor drum, such as scratches and abrasions on the photoconductor surface, image defects due to toner sticking, and shortening of the life of the photoconductor. Further, since the arrangement position of the cleaning device with respect to the image carrier is considerably specified, the degree of freedom in designing the image forming device is narrowed, and downsizing of the device is difficult.

As another method for cleaning and removing the transfer residual toner remaining on the image bearing member, a technique called a developing / cleaning system or a cleanerless system is disclosed in Japanese Patent Laid-Open No. 59-13357. Kaisho 62-20
3182, JP-A-63-133179, JP-A-64-20587, JP-A-2-302772
Japanese Patent Application Laid-Open No. 5-2289, Japanese Patent Application Laid-Open No. 5-534
No. 82 and Japanese Patent Laid-Open No. 5-61383. These are the ones that electrostatically collect the transfer residual toner on the toner carrier, but none of them mention the desirable charging characteristics of the toner.

It is also widely known to use a charge control agent to improve the chargeability of toner, and it is disclosed in JP-A-63-337.
55, JP-A-2-190869, JP-A-2
-230163 and JP-A-4-347863 disclose a method of controlling the charge of a toner with salicylic acid or a derivative thereof, and JP-A-3-84558 discloses a toner in which the dye concentration of a charge control dye on the surface of a toner particle is specified. The technology regarding is disclosed.

However, none of the above-mentioned toners is considered in the method of forming a thin layer of toner on the toner carrier or the cleaning method.

The various performances required for the above-mentioned image forming methods are often reciprocal with each other, and it has been increasingly desired in recent years to satisfy both of them to a high degree. Under such circumstances, the developing device and the toner associated therewith play a large role, and high performance is required, and it is important to design an image forming system that brings out excellent characteristics from each other. However, there is still insufficient comprehensive comprehensive response to the above issues.

[0022]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art and provide an image forming method capable of achieving high resolution and high definition image formation.

[0023]

According to the present invention, at least (a) a charging step of charging an image bearing member for bearing an electrostatic latent image; (b) electrostatic charging of the charged image bearing member by image exposure. An exposure step of forming a latent image; (c) a developing step of developing the electrostatic latent image with a toner included in a developing device to form a toner image; (d) a step of forming the toner image on the surface of an image carrier. Image formation including a transfer step of transferring a toner image to a transfer material with or without an intermediate transfer member; and (e) a cleaning step of cleaning and removing the toner remaining on the surface of the image carrier after the transfer step. In the method, the developing device comprises (1) toner applying means for supplying toner to the surface of the toner carrier by a toner applying roller arranged in contact with the surface of the toner carrier, and (2) spring elasticity. Contact with thin plate toner That Shore D hardness on the surface is 25
Layer-forming means for forming a thin layer of toner on the surface of the toner carrier by means of a toner regulating member to which a polyamide resin or a polyamide-containing elastomer having a degree of from ~ 65 degrees is adhered or molded; and (3) the toner layer as an image carrier. A developing means for achieving the formation of a toner image by contacting the surface of the toner, the toner containing at least a binder resin, a colorant, a wax component, and an oxycarboxylic acid,
The mass A (mg) of the oxycarboxylic acid extracted with methanol from 1 g of the toner and the mass B (mg) of the oxycarboxylic acid extracted with the 0.1 mol / L sodium hydroxide aqueous solution are A / B = 1 .05 to 3.00 B = 0.10 to 3.50 mg (based on the mass of the toner).

The inventors of the present invention have made earnest studies in view of the above, and as a result, (1) toner is supplied to the surface of the toner carrier by a toner application roller provided in contact with the surface of the toner carrier in the developing device. And (2) a toner regulating member in which a polyamide resin or a polyamide-containing elastomer having a Shore D hardness of 25 to 65 degrees is adhered or molded on the surface of the thin plate having spring elasticity that contacts the toner. Toner layer forming means for forming a thin layer of toner on the surface of the toner carrier, and (3) developing means for achieving the formation of a toner image by bringing the toner layer into contact with the surface of the image carrier are provided. By specifying the content and state of presence of oxycarboxylic acid in the
The present invention has been completed by finding that a uniform thin layer of toner is formed on a toner carrier and good charge is imparted, and high-resolution and high-definition image formation is achieved.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to preferred embodiments of the present invention.

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

FIG. 1 is an example of an embodiment of the image forming method of the present invention, and is a sectional view of an image forming apparatus having a process cartridge using a contact developing method using toner as a one-component developer.

In FIG. 1, a photosensitive drum 1, which is an image carrier for carrying an electrostatic latent image, rotates in the direction of arrow A and is uniformly charged by a charging roller 2. Next, the photosensitive drum 1 is exposed by the laser beam 3 emitted according to the image signal, and an electrostatic latent image is formed.

The electrostatic latent image formed on the photosensitive drum 1 is developed by, for example, a reversal developing method by disposing a developing device 4 as a process cartridge, which is removable from the image forming apparatus, close to the photosensitive drum 1. And is visualized as a toner image.

Next, the toner image on the photosensitive drum 1 is
The toner image transferred onto the recording material 13 as a transfer material by the transfer roller 9 and transferred onto the recording material 13 is fixed by the heating and pressing fixing device 12.

The residual toner remaining on the photosensitive drum 1 without being transferred is scraped off by the cleaning blade 10, collected in the waste toner container 11, and the cleaned photosensitive drum 1 is recharged. The image formation is repeated.

In the image forming method of the present invention, the developing device has a developing means for achieving the formation of a toner image by bringing a thin layer of toner on the toner carrier into contact with the electrostatic latent image carrier.

FIG. 2 is an enlarged view of the developing device 4. The developing device 4 has a developing roller 5 as a toner carrier at an opening extending in a longitudinal direction in a developing container 14 containing a toner 8 as a one-component developer.
The electrostatic latent image on the photosensitive drum 1 is developed and visualized.

In the drawing, the developing roller 5 is horizontally installed so that the right substantially half peripheral surface projects into the developing container 14 at the opening of the developing container 14 and the left substantially half peripheral surface is exposed to the outside of the developing container 14. . The developing container 14 is installed opposite to the photosensitive drum 1 located on the left side so that the toner layer formed on the exposed surface of the developing container 14 contacts.

The toner 8 may be either magnetic toner or non-magnetic toner, and the thin layer of toner formed on the developing roller 5 and the surface of the photosensitive drum 1 are in contact with each other. In the developing area, a developing bias voltage is applied to the developing roller 5. At this time, when the developing bias voltage is only a direct-current component whose constant voltage is controlled, the formation state of the toner thin layer on the toner carrier has a great influence on the development, but in the image forming method of the present invention, By using the toner regulating member and the toner, a good thin layer forming state can be obtained.

The light potential (Vl) of the photosensitive drum 1 is 0 to
-250 V, and dark part potential (Vd) is -300 to -1.
When the voltage is 000V, it is preferable that the toner supply bias voltage applied by the bias applying unit 19 is 100 to 900V and the developing bias voltage applied by the bias applying unit 18 is -100 to -900V.

Further, when the non-magnetic toner is used, the supply bias voltage applied by the bias applying means 19 should be larger than the developing bias voltage applied by the bias applying means 18 by 10 to 400 V in absolute value. This is preferable because the toner is smoothly supplied to and peeled off from the developing roller 5.

The developing roller 5 is rotationally driven in the direction of the arrow B, and the surface thereof has a high probability of rubbing against the toner 6 so that the toner 8 has an appropriate unevenness for efficient triboelectrification and good toner conveyance. Have. As the developing roller 5, for example, an elastic roller having a diameter of 16 mm is used, and the developing roller 5 is installed so as to face the photosensitive drum 1. This means that the developing roller 5 is in contact with the surface of the photosensitive drum 1 when the toner layer is removed from the developing roller 5. At this time, in order to obtain an image having no edge effect by the electric field acting between the photoconductor drum 1 and the developing roller 5 facing it through the thin layer of toner, the surface of the developing roller 5 or the vicinity of the surface is at a potential level. Therefore, it is necessary to form an electric field between the surface of the photosensitive drum 1 and the surface of the developing roller 5. Therefore, as the elastic roller preferably used for the developing roller 5, the elastic layer formed by the elastic rubber on the surface of the low-resistance core material controls the resistance in the medium resistance region to establish conduction with the surface of the photosensitive drum 1. It is possible to use a material capable of maintaining an electric field while preventing the above, a material having a low resistance conductive roller provided with a thin dielectric layer on the surface layer, and the like. Further, it is also possible to adopt a configuration in which the surface of the conductive roller is coated with an insulating substance or a conductive layer is provided on the inner surface side of the insulating roller.

In the image forming method of the present invention, the surface of the developing roller 5 as a toner carrier and the surface of the photosensitive drum 1 may rotate in the same direction or in opposite directions. When the rotation directions are the same, the peripheral speed of the surface of the developing roller 5 is preferably 105 to 300% as a peripheral speed ratio with respect to the peripheral speed of the photosensitive drum 1. By setting the peripheral speed ratio to 105 to 300%, the frequency of toner attachment / detachment with respect to the electrostatic latent image is increased, unnecessary portions are scraped off, and necessary portions are adhered to the electrostatic latent image repeatedly. Faithful to If the peripheral speed ratio is smaller than 105%, problems occur in image quality such as image density and reproducibility of fine lines. Further, when the peripheral speed ratio exceeds 300%, the amount of toner supplied to the developing unit becomes excessive and the reproducibility of the electrostatic latent image is not sufficient, and also non-uniform charging of the toner due to frictional charging with the photoconductor drum occurs. Image fogging due to surface deterioration of toner particles and matching with an image forming apparatus cause a problem.

At both ends of the developing roller 5, end seal members (not shown) for preventing toner leakage are provided at the opening of the developing container to seal both ends of the developing roller 5.

The image forming method of the present invention does not include a two-component developing method using a magnetic brush composed of toner and carrier.

Above the developing roller 5, an elastic blade 7 as a toner regulating member is supported by a blade supporting sheet metal 15, and the free end side of the elastic blade 7 is directed to the upstream side in the rotating direction of the developing roller 5, The vicinity of the tip is provided so as to contact the surface of the developing roller 5.

In the image forming method of the present invention, in the developing device, as a toner regulating member, a polyamide resin or a polyamide-containing elastomer having a Shore D hardness of 25 to 65 degrees is adhered on the surface of the thin plate having spring elasticity in contact with the toner. Alternatively, it has a toner layer forming means for forming a thin layer of toner on the surface of the toner carrier with a molded elastic blade.

If the Shore D hardness of the polyamide resin or the polyamide-containing elastomer on the surface of the elastic blade in contact with the toner exceeds 65 degrees, the content of the polyether component exhibiting good elasticity becomes low, so that the elastic blade surface becomes rigid. As described above, since excessive force is easily applied to the toner particles when passing through the elastic blade as described above, toner fusion occurs and the formation of a uniform toner layer is hindered. In addition, since the content of the amide component becomes high, the toner is excessively charged, and the image density is lowered due to the reduction of the developing efficiency, and the toner is fused due to electrostatic adhesion.

On the other hand, when the Shore D hardness is less than 25 degrees, the content of the polyamide component exhibiting a good charge imparting property becomes low, so that the desired triboelectric chargeability cannot be obtained especially for the negatively chargeable toner. In particular, it causes image fog especially in a high humidity environment.

The Shore D hardness of the polyamide resin or polyamide elastomer is measured according to "ASTM D22".
40 ".

The polyamide resin or polyamide elastomer used in the elastic blade according to the present invention is the one in which the polyamide component and the polyether component are ester-bonded or amide-bonded as described above.

Polyamide 6, as the polyamide component,
6,6,6,12,11,12,12,12, or a copolyamide obtained by polycondensation of those monomers, preferably a polyamide whose terminal amino group is carboxylated with a dibasic acid or the like is used. To be Examples of dibasic acids include oxalic acid, succinic acid, adipic acid, suberic acid, sebacic acid, aliphatic saturated dicarboxylic acids such as dodecanedioic acid, aliphatic unsaturated dicarboxylic acids such as maleic acid, phthalic acid and terephthalic acid. Aromatic dicarboxylic acid, and the above dibasic acid and ethylene glycol, butanediol,
A polydicarboxylic acid composed of a diol such as hexanediol or octanediol is used.

As the polyether component, a homopolymerized or copolymerized polyether diol such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol or the like, or a polyether diamine having both ends aminated is used.

The elastic blade according to the present invention melts a polyamide resin or a polyamide elastomer obtained by polycondensing the polyamide component and the polyether component as described above, and directly melts them on a mold equipped with a thin metal plate made of phosphor bronze. It is manufactured by injection molding.

In FIG. 2, the elastic blade 7, which is a toner regulating member, has a structure in which a polyamide elastomer is molded to a thickness of 1 mm on a thin metal plate made of phosphor bronze having a thickness of 0.1 mm. With the blade supporting sheet metal 15, the contact pressure against the developing roller 5 is 24.5 to 3
It is fixed at 4.3 N / m (25 to 35 g / cm).

In the present invention, the contact pressure is the tensile load when three thin metal plates having a known coefficient of friction are stacked and inserted into the contact portion, and the central one is pulled out by a spring or the like. However, the contact load is calculated from the value.

The elastic blade 7 has a distance NE from the contact portion with the developing roller 5 to the tip of the free end of the elastic blade 7.
Is configured so as to be continuously shortened from the central portion of the elastic blade 7 toward both ends, and at the both end portions, the tip position of the elastic blade 7 is located at the developing roller 5.
It is set so that it is in the contact portion with. That is, the layer thickness of the thin layer of toner formed on the surface of the developing roller becomes smaller as the distance NE from the contact portion between the elastic blade 7 and the developing roller 5 to the tip of the free end of the elastic blade 7 becomes shorter. Therefore, it is possible to increase the regulation force of the toner at both ends of the developing roller 5, which makes it difficult to supply the toner by the toner applying roller 6 and peel off the undeveloped toner.

The toner applying roller 6 is an elastic blade 7.
Is arranged in contact with the developing roller 5 on the upstream side in the rotating direction of the developing roller 5 and is rotatably supported. As the structure of the toner applying roller 6, the developing roller 5 has a foam skeletal sponge structure or a fur brush structure in which fibers such as rayon and nylon are planted on a core metal.
It is preferable from the viewpoint of supplying the toner 8 to the toner and peeling off the undeveloped toner. For example, an elastic roller having a diameter of 12 mm and having a polyurethane foam on a core metal is used, and the contact width with the developing roller 5 is 1 to 8 mm. It is preferable that the developing roller 5 has a relative speed at the abutting portion with respect to the developing roller 5.
Set to ~ 3mm, toner application roller 6 during development operation
The surface moving speed of (1) is rotationally driven at a predetermined timing by a driving unit (not shown) so that the peripheral speed ratio is 30 to 90% with respect to the surface moving speed of the developing roller 5.

At the time of image formation, the toner 8 in the developing container 14 is carried to the vicinity of the developing roller 5 by rotating the stirring member 16 in the direction of arrow C and the elastic roller 6 in the direction of arrow D. Further, the developing roller 5 and the toner applying roller 6 are applied on the surface of the developing roller 5 while being frictionally charged by being rubbed against each other at the contact portion.
As the developing roller 5 rotates in the direction of the arrow B, it is sent under pressure contact with the toner regulating member 7 and receives a regulating force to form a thin layer of the toner 8 on the surface of the developing roller 5, for example, a layer thickness of 10 .About.20 .mu.m, toner application amount is 0.
^{2 to} 1.0 mg / cm ² , toner charge amount -20
It is formed so as to be -60 μC / g.

At this time, the toner particles in the toner layer are appropriately filled by the contact pressure received from the elastic blade 7 as the toner regulating member, so that the toner layer is formed into a very uniform toner layer. Particularly, in the image forming method of the present invention, since the toner whose oxycarboxylic acid content state to be described later is specified is used, each toner particle can be rapidly charged by receiving the charge from the elastic blade 7. Therefore, it is possible to behave in the unit of particles without generating agglomerates due to electrostatic repulsion generated between particles, and the developing characteristics are remarkably improved. In particular, when the AC component is eliminated from the developing bias voltage applied to the toner carrier and only the DC component whose constant voltage is controlled is applied, the developing characteristics for the low potential latent image and the minute spot latent image are remarkably improved.

The transfer residual toner that has not been transferred and remains on the photosensitive drum 1 is scraped off by the cleaning blade 10 and collected in the waste toner container 11, and the cleaned photosensitive drum 1 is charged again. The image formation is repeated.

1 is used as an image forming apparatus having a process cartridge consisting of a detachable developing device, it is used as a structure in which the developing device is fixed in the main body of the image forming device and only toner is replenished. Alternatively, a developing device, a photosensitive drum, a cleaning device, a waste toner container, a charging device, and the like may be appropriately combined and used as a process cartridge.

Next, the toner image formed on the image carrier is first transferred to an intermediate transfer member as a transfer material, and the toner image transferred on the intermediate transfer member is secondly transferred to a recording material. An image forming method for performing the transfer will be described with reference to the schematic diagram of FIG.

In FIG. 3, a primary charging roller 52 that is in contact with and rotates with a photosensitive drum 51 as an image carrier.
A surface potential is provided on the photosensitive drum 51 by means of which the electrostatic latent image is formed by the exposure means 53. The electrostatic latent image is magenta toner in the contact developing type developing devices 54, 55, 56, and 57 equipped with the toner regulating member as shown in FIG.
A full-color toner image is obtained by developing with four color toners of cyan toner, yellow toner, and black toner.

The primary charging roller 52 is contact rotated in the reverse direction at a peripheral speed of 150% with respect to the rotation of the photosensitive drum, and a DC bias voltage is applied by the bias applying means (not shown).

During the developing process, developing devices 54, 55 for each color
Either one of 56 and 57 moves to the photoconductor drum 51 to be developed and a toner image is formed. The toner image formed on the photoconductor drum is transferred onto the intermediate transfer body 58, and the transfer residual toner remaining on the photoconductor drum 51 after the first transfer is removed by a cleaning device 63 having a blade 62. Then, the developing device moves to the original position again. A series of toner images are formed on the intermediate transfer member by sequentially repeating this series of operations for each developing device.

At the time of the first transfer from the photosensitive drum 51 to the intermediate transfer body 58, a DC bias voltage is applied to the support member 59 of the intermediate transfer body 58 by the bias applying means 66 to transfer the toner image.

The multiple toner images formed on the intermediate transfer member 58 are collectively second-transferred onto the recording material S as a transfer material by the transfer roller 61, and then fixed by the heating and pressing means 70. To be done.

The transfer residual toner remaining on the intermediate transfer member 58 after the second transfer is cleaned and removed by a second cleaning device 65 having a blade 64. A charging device may be used instead of the cleaning device 65. In this case, the charging device applies a charge having a polarity opposite to that of the photoconductor drum 51 to the transfer residual toner, and the transfer residual toner is removed from the photoconductive drum 51. After the surface of the intermediate transfer body 58 is cleaned by electrostatically re-transferring the toner to the surface of the intermediate transfer body 58, the transfer residual toner re-transferred onto the photosensitive drum 51 is removed by a cleaning device 63.

Thereafter, similar steps are repeatedly performed.

A drum-shaped member is used as the intermediate transfer member 58, a holding member is stretched on the outer peripheral surface, and a conductivity imparting member such as carbon black, zinc oxide, tin oxide, or silicon carbide is provided on the supporting member 59. Alternatively, it has an elastic layer 60 having a hardness of 10 to 50 degrees (JISK-6301) in which titanium oxide or the like is dispersed. A belt-shaped intermediate transfer member can be used, and in this case, it is preferable that the intermediate transfer member has an elastic layer that exhibits the hardness as described above at the transfer portion to the transfer material.

By the way, in the present invention, it is also preferable to use a developing / cleaning method in which the developing device also serves as a cleaning in the developing step, as a method of collecting the transfer residual toner which is not transferred and remains on the surface of the photosensitive member. This is one of the embodiments.

For example, in FIG. 1, when the cleaning blade 10 and the waste toner container 11 are removed, the transfer residual toner remaining on the surface of the photosensitive drum 1 without being transferred does not go through the cleaning process. When the charging roller 2 is conveyed to the charging roller 2 and passes through the contact portion between the charging roller 2 and the photosensitive drum 1,
From the above, the charge is applied together with the photosensitive drum 1. The transfer residual toner to which the charge is applied passes through the contact portion with the photosensitive drum 1 without adhering to the charging roller 2,
It can be collected by the developing roller 5.

Conventionally, the developing / cleaning method which does not require a toner recovery container is expected to contribute not only to downsizing and weight saving of an image forming apparatus but also to realizing an image forming apparatus having extremely high toner utilization efficiency. However, in the past, the transfer residual toner had a very unstable charge state, so the image carrier was charged due to poor toner collection during the development process or adhesion to the contact charging member. It had problems such as defects.

However, in the present invention, the transfer residual toner remaining on the surface of the photoconductor is in a very good charged state by the toner layer forming means by the toner regulating member as described above, so that the transfer step The influence of the transfer bias voltage in 1) is small, and since the toner described later is used, the toner can be easily collected by the developing / cleaning method in the developing step which has been very difficult in the related art. In addition, the structure can be very simple as compared with the conventional image forming apparatus using the developing and cleaning system.

In the reversal developing method, preferable conditions for carrying out the developing / cleaning method are as follows: dark potential (Vd), light potential (Vl) on the surface of the photosensitive member, and developing DC bias applied to the toner carrier. The relationship with the voltage (Vdc) is preferably set so as to satisfy | Vd−Vdc |> | V1-Vdc |. More preferably 1
0 <| Vd-Vdc |-| V1-Vdc | <400 is set, for example, Vd is about -75.
0V and Vl are about -50V, and Vdc is about -350V.

Undeveloped toner that has not been developed in the developing section is collected from the lower part of the developing roller 5 as the developing roller 5 is driven to rotate. A seal member (not shown) made of a flexible sheet is provided in the collecting portion to allow passage of undeveloped toner into the developing container, and the toner 8 inside leaks from the lower portion of the developing roller 5. Prevent.

The undeveloped toner collected in the developing container is peeled off from the developing roller 5 by the toner applying roller 6, and new toner is supplied onto the developing roller 5 as the toner applying roller 6 is rotationally driven. After that, image formation is repeatedly performed in the same manner.

As described above, in the developing device, the toner application means by the toner application roller provided in contact with the surface of the toner carrier and the surface of the thin plate having spring elasticity in contact with the toner have a Shore D hardness of 25. By providing a toner layer forming means by a toner regulating member to which a polyamide resin or a polyamide-containing elastomer having a degree of from to 65 degrees is adhered or molded, a very good thin layer of toner can be formed on the toner carrier. In particular, by using a toner in which the content of oxycarboxylic acid in the toner is specified as described below, the charge amount of the toner is kept high and the toner application state on the toner carrier such as the developing sleeve is uniform. It is possible to improve the image quality, and it is possible to form a high-resolution and high-definition image.

In the image forming method of the present invention, the toner image transferred on the intermediate transfer member as described above is secondarily transferred to the transfer material.
Even in the case of using the transfer described above, by using the toner in which the content state of the oxycarboxylic acid in the toner is specified, the influence of the transfer process can be minimized and a high-quality full-color image can be obtained.

Further, even when the developing / cleaning system is used, by using the toner in which the content state of oxycarboxylic acid in the toner is specified, the residual toner after transfer is smoothly collected, so that a high-quality image is obtained. Can be stably formed over a long period of time.

One of the characteristics of the image forming method of the present invention is to use a toner having a specified oxycarboxylic acid content.

The toner according to the present invention contains at least a binder resin, a colorant, a wax component, and an oxycarboxylic acid, and has a mass A (mg) of the oxycarboxylic acid extracted with methanol from 1 g of the toner and 0. 1 mol / L
So that the mass B (mg) of the oxycarboxylic acid extracted by the aqueous sodium hydroxide solution of A satisfies the following conditions: A / B = 1.05 to 3.00 B = 0.10 to 3.50 mg (based on the mass of the toner) The content state of oxycarboxylic acid is specified.

As a result of earnest studies, the inventors of the present invention have formed a high-resolution and high-definition image by using a toner having a specified oxycarboxylic acid content in a developing device equipped with the toner layer forming means as described above. It was found that the image deterioration can be reduced not only when printing out a large number of sheets but also under severe use conditions such as restarting use after being left in a high temperature and high humidity environment for a long time. .

Although these reasons are not always clear, according to the findings of the present inventors, in addition to the fact that the oxycarboxylic acid used in the present invention makes it difficult for the toner particles to retain an opposite charge, By specifying the content state in the toner, it is possible to impart a quick and uniform charging characteristic, and the charge polarity control and the charge amount control can be performed more reliably and uniformly. Further, even when the toner is regulated by the toner regulating member as described above, the charge can be rapidly transferred without being affected by the use environment, so that each toner particle can be rapidly charged. Further, since the formation state of the toner layer on the toner carrier such as the developing roller is synergistically improved, the degree of image deterioration can be significantly reduced even when the toner layer is left in a high temperature and high humidity environment for a long period of time. It has become possible.

The mass A of the oxycarboxylic acid extracted from 1 g of the toner with methanol (hereinafter referred to as “amount of oxycarboxylic acid A”) is present on the surface of the toner particles and on the surface layer portion (near the surface) where methanol can penetrate. The amount of oxycarboxylic acid present (mg), and toner 1
The mass B of the oxycarboxylic acid extracted from 0.1 g of the sodium hydroxide aqueous solution of 0.1 mol / L (hereinafter referred to as "oxycarboxylic acid amount B") is the amount of the oxycarboxylic acid present on the surface of the toner particles. (Mg),
It is considered that each of these controls the toner charge amount and charge speed. In particular, even in the case of a non-magnetic toner that is not magnetically restrained by the toner carrier, good triboelectric charging is imparted by the toner regulating member according to the present invention as described above, so that an excellent thin layer of toner is obtained. It is possible to form a high-definition image with high resolution even in a contact development method in which only a direct current component whose low voltage is controlled as a development bias voltage is applied.

That is, the amount of oxycarboxylic acid A extracted with methanol from 1 g of toner and 0.1 mol / L
The value of A / B, which is the ratio of the amount B of oxycarboxylic acid extracted by the aqueous sodium hydroxide solution, is 1.05 to 3.0.
By setting the value to 0, an appropriate amount of charge can be imparted to the toner particles by the effect of suppressing the charging of the oxycarboxylic acid existing on the toner surface due to moisture absorption and the effect of imparting the electrostatic charge of the oxycarboxylic acid existing near the surface.

Further, the amount B of oxycarboxylic acid is 0.10 to
By setting the amount to 3.50 mg, the charging speed of the toner becomes good.

Furthermore, when the amount A of oxycarboxylic acid and the amount B of oxycarboxylic acid have a relationship of satisfying A ≦ (3/4) B + 1, not only when printing a large number of sheets, but also when left for a long time in a high temperature and high humidity environment. It is possible to reduce image deterioration even under severe use conditions such as reuse after being used.

In the present invention, the amount of oxycarboxylic acid A extracted with methanol from 1 g of toner is 0.1
The amount B of oxycarboxylic acid extracted with a mol / L sodium hydroxide aqueous solution is measured by the following method.

That is, 50 ml of a 0.1 mol / L sodium hydroxide aqueous solution containing methanol and 0.04 g of contaminone as a dispersant was prepared in separate containers, and 1 g of the toner was weighed and added into each container. Using 50
Stir at rpm to disperse evenly. After performing dispersion treatment for 3 hours, a membrane filter (pore size: 0.4
5 μm) and the absorbance of the obtained filtrate is measured. From the obtained results, by using a predetermined calibration curve, the mass A (mg) of oxycarboxylic acid extracted with methanol from 1 g of the toner and 0.1 mol / L
The mass B (mg) of the oxycarboxylic acid extracted by the aqueous sodium hydroxide solution can be determined.

The oxycarboxylic acid according to the present invention includes
Although known compounds can be used, compounds represented by the following general formulas (1) and (2) are preferably used from the viewpoint of charge imparting ability.

[0089]

[Chemical 4] [In the above formula (1), (A) is selected from the following group and X ₁
Represents a hydrogen atom, a sodium atom, a potassium atom, ammonium or an aliphatic ammonium. ]

[0090]

[Chemical 5]

[0091]

[Chemical 6] [In the above formula (2), X ₂ represents a hydrogen atom, a sodium atom, a potassium atom, ammonium, or an aliphatic ammonium, and R ₄ represents a C _{1 to} C ₂₂ alkyl group, an alkenyl group, or an aryl group. , R ₅ is a hydrogen atom, C ₁ -C
_{22 represents} an alkyl group, an alkenyl group, an aryl group or an alkoxy group. ]

Among the oxycarboxylic acids represented by the above general formulas (1) and (2), those preferably used in the present invention are oxycarboxylic acids having an aromatic ring, and monoalkyl aromatic oxycarboxylic acids. An acid or a dialkyl aromatic oxycarboxylic acid may be mentioned. In particular, salicylic acid, ditert-butylsalicylic acid and 5-tert
-Alkylsalicylic acid represented by octylsalicylic acid, hydroxynaphthoic acid, benzylic acid and the like are preferably used in the present invention because they can be easily immobilized on the toner surface.

Typical examples of specific compounds are listed below.

[0094]

[Chemical 7]

[0095]

[Chemical 8]

[0096]

[Chemical 9]

[0097]

[Chemical 10]

[0098]

[Chemical 11]

The toner according to the present invention has a circle-equivalent number average diameter D ₁ (μm) of 2 in a circle-equivalent diameter-circularity scattergram based on the number of toner particles measured by a flow-type particle image measuring device. -10 μm, the average circularity of the toner is 0.920 to 0.995, and the toner particle shape is precisely controlled so that the circularity standard deviation is less than 0.040. And the transferability can be improved in a well-balanced manner.

That is, the circle-equivalent number average diameter D ₁ (μ
By reducing the m) to 2 to 10 μm, more preferably 3 to 6 μm, the reproducibility of the outline portion of the image, especially the character image or the line pattern in the development is improved.

Generally, when the toner particle size is reduced, the abundance ratio of the toner of fine particles is inevitably increased, so that it is difficult to uniformly charge the toner, which causes image fog, and is also matched with the image forming apparatus. It also caused trouble.

However, in the toner according to the present invention, the average circularity of the circularity frequency distribution of toner particles is 0.920 to 0.920.
0.995, preferably 0.950 to 0.995, more preferably 0.970 to 0.990,
The transferability of toner with a small particle size, which was difficult in the past, has been significantly improved, and the developing ability for low-potential latent images and the recoverability of toner when using the developing / cleaning method as described above are significantly improved. To do. In particular, the above tendency is very effective when developing a minute spot latent image of a digital system or when forming a full-color image in which a large number of transfers are performed by using an intermediate transfer member, and the matching with an image forming apparatus is also good. It will be

Further, in the toner of the present invention, the circularity standard deviation of the circularity frequency distribution of toner particles is set to less than 0.040, preferably less than 0.035, more preferably 0.015 or more and less than 0.030. As a result, when the thin layer of toner is formed on the toner carrier, the toner charge amount can be made appropriate, and the problems as described above can be greatly improved.

Further, in the circularity frequency distribution, by setting the toner particles having a circularity of less than 0.950 to 15% by number or less, the state of forming a thin layer of toner on the toner carrier is further improved. The formation is also good.

By the way, generally, when a toner having a specific particle size distribution or shape distribution as described above is used, a thin layer of toner is attached to the surface of a toner carrier such as a developing roller by bringing a thin plate having spring elasticity into contact with the toner. In some cases, a phenomenon of slipping-off of toner particles occurs during the formation of the toner particles, and in particular, remarkable image deterioration is often caused under severe use conditions such as restarting use after being left in a high temperature and high humidity environment for a long time. However, in the toner of the present invention, since the content state of the oxycarboxylic acid in the toner is specified and the toner layer forming means by the toner regulating member as described above is used, the charge can be uniformly applied to the toner. Therefore, the image deterioration as described above can be reduced.

The equivalent circle diameter, the circularity and their frequency distribution of the toner in the present invention are used as a simple method for quantitatively expressing the shape of toner particles, and in the present invention, the flow type particle image measurement is performed. Device "FPIA-1000"
(Manufactured by Toa Medical Electronics Co., Ltd.) was used for the measurement, and the following formula was used for calculation.

[0107]

[Equation 1]

Here, the “particle projection area” is the area of the binarized toner particle image, and the “perimeter of the particle projection image”.
Is defined as the length of the contour line obtained by connecting the edge points of the toner particle image.

The circularity in the present invention is an index showing the degree of unevenness of the toner, and it is 1.000 when the toner is a perfect sphere, and the more the surface shape becomes complicated, the smaller the circularity becomes.

In the present invention, the circle-equivalent number average diameter D ₁ (μ, which means the average value of the particle size frequency distribution based on the number of toner particles)
m) and the particle size standard deviation SDd are calculated from the following equations, where di is the particle size (center value) at the dividing point i of the particle size distribution and f _i is the frequency.

[0111]

[Equation 2]

[0112]

[0113]

[Equation 3]

As a specific measuring method, 10 ml of ion-exchanged water from which impure solids and the like have been removed beforehand was prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, was added as a dispersant into the container. Then, 0.02 g of a measurement sample is further added and uniformly dispersed. As a means for dispersing, an ultrasonic disperser "UH-50 type" (manufactured by SMT) equipped with a titanium alloy chip of 5φ as a vibrator was used, and a dispersion treatment for 5 minutes was performed using a dispersion treatment for 5 minutes. To do. At that time, the dispersion is appropriately cooled so that the temperature of the dispersion does not exceed 40 ° C.

The flow type particle image measuring device was used for measuring the toner shape, and the toner particle concentration at the time of measurement was 3000.
The concentration of the dispersion liquid is readjusted to be about 10,000 particles / μl, and 1,000 or more toner particles are measured. After the measurement, this data is used to determine the equivalent circle diameter of the toner, the circularity frequency distribution, and the like.

The wax component according to the present invention is used for observing a tomographic plane of a toner using a transmission electron microscope (TEM).
(1) 0.9 with respect to the weight-average circle-equivalent diameter D ₄ (μm) of the toner based on the weight of the toner measured by a flow-type particle image measuring device
Twenty tomographic planes of toner particles exhibiting a major axis R (μm) satisfying the relationship of ≦ R / D ₄ ≦ 1.1 are selected, and (2) a phase caused by a wax component present in the tomographic planes of the selected toner particles. Longest diameter r of the largest separation structure
And (3) the calculated arithmetic mean value (r / R) _{st of} r / R is 0.05 ≦ (r / R) _st ≦ 0.95.
In order to satisfy the above condition, it is preferable that the wax component is dispersed in the binder resin in a substantially spherical and / or spindle-shaped island shape.

Arithmetic mean value (r / R) of the above r / R
_st is, 0.05 ≦ by the wax component is dispersed so as to satisfy the _{(r / R) st ≦ 0.95} , localized charge control agent oxy carboxylic acid or later in the vicinity of the surface of efficiently toner particles Therefore, it contributes to the stabilization of the chargeability of the toner, and the effect of fixing these in the vicinity of the toner particle surface can be maintained. Further, by encapsulating the wax component in the toner particles, it is possible to prevent contamination of the image forming apparatus and deterioration of the toner surface. In particular, it is preferably used for an image forming method using a developing means for achieving the formation of a toner image by bringing the toner layer into contact with the surface of the image carrier.

Furthermore, the arithmetic mean value of r / R (r / R)
_{When st} is in a dispersed state satisfying 0.25 ≦ (r / R) _st ≦ 0.90, it is possible to maintain a good chargeability and form a toner image excellent in dot reproduction for a long period of time. Therefore, it is preferable. Further, when the developing / cleaning method is used, it is possible to reduce the influence from the transfer step, which facilitates the recovery of the transfer residual toner, which is preferable.

In the toner according to the present invention, the specific surface area of the toner is reduced by controlling the particle shape of the toner as described above. Therefore, the toner particles contain the oxycarboxylic acid and the wax component. The effect of identifying the condition becomes significant.

As a method of observing the tomographic plane of the toner particles, one of the components is separated by a heavy metal by utilizing the difference in the fine structure of the crystalline phase and the amorphous phase between the wax component used and the binder resin constituting the outer shell. It is preferable to use an electron dyeing method in which the electron density is increased to provide contrast between materials. Specifically, after the toner particles are sufficiently dispersed in a room temperature curable epoxy resin, the toner particles are cured in an ambient temperature of 40 ° C. for 2 days, and the obtained cured product is ruthenium tetraoxide (Ru).
O ₄ ) and, if necessary, osmium tetroxide (OsO ₄ )
After performing the electronic dyeing in combination with the above, a flaky sample is cut out using an ultramicrotome equipped with a diamond knife, and the cross-sectional layer morphology of the toner is observed using a transmission electron microscope (TEM).

A typical example is shown in FIGS. 4 (a) and 4 (b). In the toner particles obtained in the examples described below, it was observed that the wax component was encapsulated by the binder resin.

The wax component used in the present invention has a main endothermic peak temperature (melting point) of 3 in the DSC curve measured according to "ASTM D3418-82".
Compounds in the range of 0 to 120 ° C, more preferably 40 to 90 ° C are preferred.

By using the wax component exhibiting the thermal characteristics as described above, not only the good fixing property of the obtained toner but also the releasing effect by the wax component is efficiently exhibited, and a sufficient fixing region is secured. It is possible to eliminate the adverse effects on the developability, blocking resistance and image forming apparatus due to the conventionally known wax component. In particular, since the specific surface area of the toner decreases as the particle shape of the toner becomes spherical, controlling the thermal characteristics and dispersion state of the wax component becomes very effective.

To measure the main endothermic peak temperature (melting point) of the wax component, for example, "DSC-7" (manufactured by Perkin Elmer Co., Ltd.) is used. The melting points of iridium and zinc are used to correct the temperature of the device detection unit, and the heat of fusion of iridium is used to correct the amount of heat. At the time of measurement, set a measurement sample placed in an aluminum pan and an aluminum pan only (empty pan) for comparison,
The main endothermic peak temperature (melting point) is determined from the DSC curve obtained when the temperature in the measurement region of 180 ° C. is increased at a temperature increase rate of 10 ° C./min. When measuring only the wax component, the temperature is raised and lowered under the same conditions as the measurement to remove the previous history, and then the measurement is started. Further, when measuring the wax component contained in the toner, the measurement is performed as it is without performing the operation of removing the previous history.

As the wax component usable in the present invention, specifically, petroleum wax such as paraffin wax, microcrystalline wax, petrolactam and its derivatives, montan wax and its derivatives,
Examples include hydrocarbon waxes and their derivatives by the Fischer-Tropsch method, polyolefin waxes and their derivatives represented by polyethylene, natural waxes such as carnauba wax and candelilla wax, and their derivatives. The derivatives include oxides and vinyl monomers. Also included are block copolymers with and graft modified products. In addition, alcohols such as higher aliphatic alcohols; fatty acids such as stearic acid and palmitic acid or compounds thereof; acid amides, esters, ketones, hydrogenated castor oil and its derivatives, vegetable wax, animal wax. These can be used alone or in combination.

Among them, when polyolefin, hydrocarbon wax by the Fischer-Tropsch method, petroleum wax, higher alcohol, or higher ester is used, the effect of improving the developability and transferability is further enhanced. An antioxidant may be added to these wax components within a range that does not affect the charging property of the toner.

These wax components are based on the binder resin 100.
It is preferable to use 1 to 30 parts by mass with respect to parts by mass.

Examples of the binder resin of the toner used in the present invention include commonly used styrene- (meth) acrylic copolymers, polyester resins, epoxy resins and styrene-butadiene copolymers. In the method of directly obtaining toner particles by a polymerization method, a monomer for forming them is used. Specifically, styrene; o
Styrene-based monomers such as-(m-, p-) methylstyrene and m- (p-) ethylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth ) Butyl acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth)
(Meth) acrylic acid ester type monomers such as dimethylaminoethyl acrylate and diethylaminoethyl (meth) acrylate; ene type monomers such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile and acrylic acid amide are preferably used. To be These may be used alone or generally in the publication Polymer Handbook Second Edition III-P 139-192 (John Wiley).
& Sons) glass transition temperature (Tg)
However, it is used by appropriately mixing the monomers so as to show 40 to 75 ° C. When the theoretical glass transition temperature is lower than 40 ° C, problems tend to occur from the viewpoint of storage stability and durability stability of the toner, while when it exceeds 75 ° C, the fixing point of the toner is increased.

Further, in the present invention, it is preferable to use a crosslinking agent at the time of synthesizing the binder resin in order to increase the mechanical strength of the toner particles.

As the cross-linking agent used in the toner of the present invention, as a bifunctional cross-linking agent, divinylbenzene, bis (4-acryloxypolyethoxyphenyl) propane,
Ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate , Triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 200, # 400, # 600 diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester type diacrylate (MANDA Nippon Kayaku), And those in which the above diacrylate is replaced with methacrylate.

As the polyfunctional crosslinking agent, pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate and its methacrylate, 2,
Examples include 2-bis (4-methacryloxy, polyethoxyphenyl) propane, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate and triallyl trimellitate.

These cross-linking agents are used as the other vinyl-based monomer 1.
The amount is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 00 parts by mass.

In the present invention, a polar resin such as polyester resin or polycarbonate resin (hereinafter referred to as “polar resin”) can be used together with the above-mentioned binder resin. By adding polar resin in the toner,
It becomes easy to control the content state of the polymer having a sulfonic acid group and the oxycarboxylic acid in the toner to the specific state as described above.

For example, in the case of directly producing a toner by a suspension polymerization method or the like which will be described later, when the polar resin as described above is added during the polymerization reaction from the dispersion step to the polymerization step, the polymerizable monomer which becomes the toner particles is added. Depending on the balance between the polarities of the composition and the aqueous dispersion medium, the added polar resin may form a thin layer on the surface of the toner particles, or may be controlled so as to have a gradient from the surface of the toner particles toward the center. it can. At this time, by using a polar resin having an interaction with the oxycarboxylic acid, it is possible to make the existing state of the oxycarboxylic acid in the toner into a desired form. In particular, when a polar resin having an acid value of 1 to 20 mgKOH / g is used, it becomes easy to control the existing state of oxycarboxylic acid.

The addition amount of the polar resin is 100% by weight of the binder resin 100.
It is preferable to use 1 to 25 parts by weight with respect to parts by weight,
It is more preferably 2 to 15 parts by mass. If it is less than 1 part by mass, the state of existence of the polar resin in the toner particles becomes non-uniform, and conversely, if it exceeds 25 parts by mass, the thin layer of the polar resin formed on the surface of the toner particles becomes thick. It becomes difficult to control the contained state of the carboxylic acid, and the function cannot be sufficiently expressed.

The composition of a typical polyester resin used as the polar resin is as follows.

As the alcohol component of the polyester resin, ethylene glycol, propylene glycol, 1,
3-butanediol, 1,4-butanediol, 2,3
-Butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl 1,3-hexanediol, hydrogenated bisphenol A,
Examples thereof include bisphenol derivatives represented by the following formula (a) and diols represented by the following formula (a).

[0138]

[Chemical 12]

[0139]

[Chemical 13]

It is also a preferred embodiment of the present invention to use a reactive polyester resin or a polycarbonate resin as the polar resin. When these polar resins are used, the charging characteristics of the toner are improved, image fog and scattering are improved, and a high-quality image having excellent dot reproducibility can be obtained. Further, it becomes possible to impart an appropriate mechanical strength to the toner particles, minimize the influence of toner deterioration received from the image forming apparatus, and durability against a large number of printouts and matching with the image forming apparatus described later. improves. Furthermore, it is possible to minimize the influence of the toner manufacturing process such as the sphering treatment of the toner for achieving the toner shape distribution as described above and the drying treatment when the toner is directly produced by the polymerization method. Also,
It is possible to use two or more kinds of polar resins in combination, and it is also possible to utilize the chargeability of the polar resin itself.

The reactive polyester resin according to the present invention means terephthalic acid, isophthalic acid, phthalic acid, adipic acid, maleic acid, succinic acid, sebacic acid, thiodiglycolic acid, diglycolic acid, malonic acid, glutaric acid, Polybasic acids such as pimelic acid, suberic acid, azelaic acid, camphoric acid, cyclohexanedicarboxylic acid, trimellitic acid; ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol , 1,4-butanediol, neopentyl glycol, 1,4-bis (hydroxymethyl) cyclohexane, 1,4-bis (2-hydroxyethyl) benzene, 1,4-cyclohexanedimethanol, polyethylene glycol, polypropylene glycol, Bisfe Lumpur A, hydrogenated bisphenol, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, glycerol, trimethylolpropane, and polyhydric alcohols such as pentaerythritol be one obtained by condensation polymerization,
The obtained condensation polymer has a reactive group in the main chain or side chain. The reactive group means carboxylic acid (or salt thereof), sulfonic acid (or salt thereof), ethyleneimino acid,
Epoxy group, isocyanate group, double bond, acid anhydride,
Various things such as halogen atom can be exemplified, and this reactive polyester resin is reacted with each other or with a polyfunctional crosslinking agent (for example, polyhydric alcohol, polybasic acid, etc.) THF by reacting vinyl monomers (eg esterification, copolymerization, etc.)
Insoluble matter can be obtained. For example, when the toner is obtained by a polymerization method, an unsaturated polyester resin is used as the reactive polyester resin, and this is copolymerized with a vinyl monomer (including a crosslinking agent such as divinylbenzene if necessary). In this case, the polar unsaturated polyester resin migrates to the vicinity of the toner surface with the progress of polymerization and forms a thin layer on the surface of the toner particles, so that a toner excellent in blocking resistance and offset resistance can be obtained. It is possible to obtain.

As the reactive polyester resin which can be used in the present invention, any one can be used as long as it contains the reactive group as described above. However, if the molecular weight is too low, a polyester resin which is not suitable for the crosslinking reaction can be used. It may be present on the toner surface and the blocking resistance may be lowered. Further, when the toner has a too high molecular weight, for example, when a toner is obtained by a polymerization method, it becomes difficult to dissolve the reactive polyester resin in the vinyl-based monomer, which makes the production difficult. Therefore, the weight average molecular weight of the reactive polyester resin is preferably about 3,000 to 100,000 in order to obtain a toner having particularly excellent performance.

On the other hand, as the polycarbonate resin according to the present invention, a polycarbonate resin having a repeating unit represented by the following general formula (I) in the molecular structure is preferably used.

[0144]

[Chemical 14] [In formula, R shows an organic group. ]

The above general formula (I) has various structures. For example, it is possible to use any known polycarbonate produced by reacting a dihydric phenol with a carbonate precursor by a solution method or a melting method. The following general formula (II) can be used.

[0146]

[Chemical 15] [In the formula, R ² is a hydrogen atom, an aliphatic hydrocarbon group, or an aromatic substituent, and when there are plural R ² 's, they may be the same or different, and m is , 0-4. Z is a single bond, an aliphatic hydrocarbon group, an aromatic substituent, -S -, - SO -, - SO 2 -, - O -, - CO
-Indicates a bond represented by a bond. And a polymer having a repeating unit represented by the formula:

The polycarbonate resin may be various ones, but is usually represented by the general formula (III) to
(V)

[0148]

[Chemical 16]

[0149]

[Chemical 17]

[0150]

[Chemical 18] [In the formula, R ² , m and Z are the same as defined above. ] It can be easily produced by reacting a dihydric phenol represented by the above with a phosgene or a carbonate precursor such as a carbonate compound. That is, for example, by reacting a dihydric phenol with a carbonate precursor such as phosgene in a solvent such as methylene chloride in the presence of a known acid acceptor or a molecular weight regulator, or by reacting dihydric phenol with diphenyl carbonate. It is produced by a transesterification reaction with various carbonate precursors.

There are various dihydric phenols represented by the above general formulas (III) to (V), and 2,2-
Starting with bis (4-hydroxyphenyl) propane [common name: bisphenol A], for example, bis (4-hydroxyphenyl) methane; bis (4-hydroxyphenyl)
Phenylmethane; Bis (4-hydroxyphenyl) naphthylmethane; Bis (4-hydroxyphenyl)-(4-
Isopropylphenyl) methane; bis (3,5-dimethyl-4-hydroxyphenyl) methane; 1,1-bis (4-hydroxyphenyl) ethane; 1-naphthyl-
1,1-bis (4-hydroxyphenyl) ethane; 1-
Phenyl-1,1-bis (4-hydroxyphenyl) ethane; 1,2-bis (4-hydroxyphenyl) ethane; 2-methyl-1,1-bis (4-hydroxyphenyl) propane; 2,2-bis (3,5-dimethyl-4-
Hydroxyphenyl) propane; 1-ethyl-1,1-
Bis (4-hydroxyphenyl) propane; 2,2-bis (3-methyl-4-hydroxyphenyl) propane;
1,1-bis (4-hydroxyphenyl) butane; 2,
2-bis (4-hydroxyphenyl) butane; 1,4-
Bis (4-hydroxyphenyl) butane; 2,2-bis (4-hydroxyphenyl) pentane; 4-methyl-
2,2-bis (4-hydroxyphenyl) pentane;
1,1-bis (4-hydroxyphenyl) cyclohexane; 2,2-bis (4-hydroxyphenyl) hexane; 4,4-bis (4-hydroxyphenyl) heptane; 2,2-bis (4-hydroxyphenyl) Nonan;
1,10-bis (4-hydroxyphenyl) decane;
Dihydroxyarylalkanes such as 1,1-bis (4-hydroxyphenyl) cyclodecane, bis (4-hydroxyphenyl) sulfone; dihydroxyarylsulfones such as bis (3,5-dimethyl-4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ether; dihydroxyaryl ethers such as bis (3,5-dimethyl-4-hydroxyphenyl) ether, 4,4′-dihydroxybenzophenone; 3,
Dihydroxy aryl ketones such as 3 ′, 5,5′-tetramethyl-4,4′-dihydroxybenzophenone, bis (4-hydroxyphenyl) sulfide; bis (3-methyl-4-hydroxyphenyl sulfide; bis (3, Dihydroxyaryl sulfides such as 5-dimethyl-4-hydroxyphenyl) sulfide, dihydroxyaryl sulfoxides such as bis (4-hydroxyphenyl) sulfoxide, dihydroxydiphenyls such as 4,4′-dihydroxydiphenyl, hydroquinone; zorcinol; Dihydroxybenzenes such as methylhydroquinone, 1,5-dihydroxynaphthalene;
Examples thereof include dihydroxynaphthalenes such as 2,6-dihydroxynaphthalene. These dihydric phenols may be used alone or in combination of two or more.

Examples of the carbonic acid ester compound include diaryl carbonate such as diphenyl carbonate and dialkyl carbonate such as dimethyl carbonate and diethyl carbonate.

The polycarbonate resin used in the present invention may be a homopolymer using one of these dihydric phenols, or a copolymer using two or more thereof, or It may be a blend. Further, it may be a thermoplastic random branched polycarbonate resin obtained by reacting a polyfunctional aromatic compound with the above dihydric phenol and / or carbonate precursor.

Further, in order to adjust the glass transition temperature and viscoelasticity of the polycarbonate resin, part of the dihydric phenol is replaced with ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol,
1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-bis (hydroxymethyl) cyclohexane, 1,4-bis (2-hydroxyethyl) benzene, 1,4-cyclohexanedimethanol, Modification of polyethylene glycol, propylene glycol, hydrogenated bisphenol A and its derivatives, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, polyhydric alcohol such as glycerin, trimethylolpropane, pentaerythritol, etc. A polycarbonate resin is also preferably used. In this case, it is possible to simply replace a part of the dihydric phenol with the above-mentioned method, but as another example of the production method, the dihydric phenol and the aliphatic or aromatic bischloroformate may be used. Examples thereof include a method in which and are reacted in a methylene chloride solvent using pyridine as a catalyst, but, of course, synthesis by other production methods is also possible.

Further, in the present invention, as the polycarbonate resin, the above-mentioned polycarbonate and polystyrene, styrene- (meth) acrylic copolymer, polyester, polyurethane, epoxy resin, polyolefin,
Use of block copolymers with polyamides, polysulfones, polycyanoaryl ethers, polyarylene sulfides, etc., and graft modified copolymers grafted with alkyl (meth) acrylate, (meth) acrylic acid, maleic acid, styrene-based monomers, etc. It is possible.

The molecular weight of the polycarbonate resin used in the present invention is not particularly limited, but it is preferable that the peak molecular weight measured by GPC is in the range of 1000 to 500,000, and more preferably 2000 to 500.
It is 100,000. If the peak molecular weight is less than 1000, the charging characteristics may be adversely affected, and the peak molecular weight may be 500000.
If it is higher than this, the melt viscosity becomes too high, which may cause a problem in fixing property. Further, in producing the polycarbonate resin used in the present invention, an appropriate molecular weight modifier, a branching agent for improving viscoelasticity, a catalyst for accelerating the reaction and the like can be used if necessary.

The above-mentioned polar resins are not limited to one kind of polymer, and for example, two or more kinds of reactive polyester resins may be used at the same time, or two or more kinds of vinyl polymers may be used. It is possible, and further, completely different types of polymers, such as non-reactive polyester resin, epoxy resin, polycarbonate resin, polyolefin, polyvinyl acetate, polyvinyl chloride, polyalkyl vinyl ether, polyalkyl vinyl ketone,
Various polymers such as polystyrene, poly (meth) acrylic ester, melamine formaldehyde resin, polyethylene terephthalate, nylon and polyurethane can be added to the binder resin as required.

Generally, the thin layer formed on the surface of the toner particles by the polar resin as described above has a ruthenium tetroxide (RuO 4) content in the tomographic surface observation of the toner particles using the transmission electron microscope (TEM) as described above. ₄ ) and / or osmium tetroxide (OsO ₄ ) for identification by electron staining. At this time, the binder resin and the wax component are present in the toner inward direction of the thin layer formed on the surface of the toner particles, and the wax component is substantially spherical and / or spindle-shaped island-shaped in the binder resin. It is observed that they are dispersed in. Representative examples are shown in FIGS. 4 (c) and 4 (d).
As shown in FIG. 4C, a state in which a thin layer covers the surface of the toner particles substantially uniformly is defined as a continuous layer.
A state in which the thin layer partially covers the surface of the toner particles as in (d) is defined as a discontinuous layer.

The colorants used in the present invention include the following yellow colorants, magenta colorants and cyan colorants. Black colorants include carbon black, magnetic substances or the following yellow colorants / magenta colorants. / A black color mixture is used by mixing a cyan colorant.

The carbon black used in the present invention is
The nitrogen adsorption specific surface area is preferably 100 m ² / g or less, and when the nitrogen adsorption specific surface area is larger than 100 m ² / g, it becomes difficult to disperse it in the toner, which causes a problem in the chargeability and coloring power of the toner. Further, it is not suitable for use because it affects the polymerizability of the monomer when the toner is produced by the polymerization method.

The BET specific surface area of carbon black is measured according to "ASTM D3037-78".

D of carbon black used in the present invention
The BP oil absorption is desirably 40 to 150 ml / 100 g.

Carbon black having a short structure having a DBP oil absorption of less than 40 ml / 100 g tends to cause the toner charge amount to be too low, while exceeding 150 ml / 100 g makes it difficult to obtain a fine dispersion of carbon black because of a strong long structure. .

The measurement of the DBP oil absorption is conducted according to "ASTM D2
414-79 ”.

As the yellow colorant used in the present invention, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds and allylamide compounds are used. Specifically, for example, C.I. I. Pigment Yellow 12, 1
3, 14, 15, 17, 62, 74, 83, 93, 9
4, 95, 97, 109, 110, 111, 120, 1
27, 128, 129, 147, 168, 174, 17
6,180,181,191 etc. are used suitably.

As the magenta colorant used in the present invention, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds,
A thioindigo compound and a perylene compound are used. Specifically, for example, C.I. I. Pigment Red 2, 3,
5, 6, 7, 23, 48: 2, 48: 3, 48: 4,5
7: 1, 81: 1, 144, 146, 166, 169,
177, 184, 185, 202, 206, 220, 2
It is particularly preferable to use No. 21, 254 and the like.

As the cyan colorant used in the present invention, a copper phthalocyanine compound and its derivative, an anthraquinone compound, a basic dye lake compound and the like can be used.
Specifically, for example, C.I. I. Pigment Blue 1,
7, 15, 15: 1, 15: 2, 15: 3, 15: 4,
60, 62, 66 and the like are particularly suitable.

These colorants may be used alone or in a mixture, and further, they may be used in a solid solution state. The amount of the colorant added to the toner is preferably 40 to 150 parts by mass with respect to 100 parts by mass of the binder resin when a magnetic material is used as the colorant. When the agent is used, it is preferably used in an amount of 5 to 20 parts by mass with respect to 100 parts by mass of the polymerizable vinyl monomer.

Further, in the present invention, a magnetic toner may be prepared by containing a magnetic material. In this case, the magnetic material can also serve as a coloring agent. Examples of the magnetic material that can be used in the present invention include iron oxides such as magnetite, hematite and ferrite; metals such as iron, cobalt and nickel; or these metals and aluminum, cobalt, copper, lead, magnesium, tin and zinc. , Antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, alloys with metals such as vanadium, and mixtures thereof.

Further, as these magnetic materials used in the present invention, more preferably surface-modified magnetic materials are used. In particular, when a toner is produced by a polymerization method, it is preferable to use a toner that has been subjected to a hydrophobic treatment with a surface modifier that does not inhibit polymerization. Examples of such surface modifiers include silane coupling agents and titanium coupling agents.

Further, these magnetic materials have an average particle size of
Of 1 μm or less, preferably 0.1 to 1 μm
It is good. As a magnetic material, 795.8 kA / m (10
As a magnetic characteristic under the application of k eslutted, coercive force (H
_c) Is 1.59 to 23.9 Am²/ G (20 to 300 d
Rusted), saturation magnetization (σ_S) Is 50 to 200 Am ²/
g, remanent magnetization (σ_r) Is 2 to 20 Am²Use / g
Preferably.

In the present invention, a known charge control agent can be used in combination with the above-mentioned oxycarboxylic acid, and a charge control agent having a particularly high charging speed and capable of stably maintaining a constant charge amount is preferable. At this time, when the toner particles are directly polymerized, a charge control agent having no polymerization inhibitory property and having no solubilized product in the aqueous dispersion medium is preferable. Specific compounds include metal compounds of carboxylic acids such as salicylic acid, naphthoic acid and dicarboxylic acid as negative charge control agents; polymer type compounds having a sulfonic acid or carboxylic acid group in the side chain; boron compounds; urea compounds; Silicon compounds; curlyx arenes and the like can be mentioned. Examples of the positive charge control agent include a quaternary ammonium salt; a polymer type compound having the quaternary ammonium salt in its side chain; a guanidine compound; an imidazole compound.

Of these, 2-acrylamido-2-methylpropanesulfonic acid is particularly preferable at a copolymerization ratio of 2% by mass.
As described above, a high-molecular compound containing styrene and / or styrene (meth) acrylic acid copolymer having a glass transition temperature (Tg) of 40 to 70 ° C., which is contained in an amount of 5% by mass or more, is preferable, and is bound to the toner. By containing 2 to 10 parts by mass with respect to 100 parts by mass of the coating resin, the charge state of the toner can be further improved by the combined use with the oxycarboxylic acid according to the present invention.

The addition of inorganic fine powder to the toner of the present invention is a preferred embodiment for improving the developability, transferability, charge stability, fluidity and durability. As the inorganic fine powder, known ones can be used, but it is particularly preferable to select from silica, alumina, titania or a complex oxide thereof. Furthermore, silica is more preferable. For example, as the silica, both a so-called dry method produced by vapor phase oxidation of a silicon halide or an alkoxide or a dry silica called fumed silica and a so-called wet silica produced from alkoxide, water glass, etc. can be used. However, there are few silanol groups on the surface and inside the silica fine powder, and Na ₂ O, SO ₃
Dry silica having less production residue such as ^2- is preferable. Further, in the case of dry silica, it is also possible to obtain a composite fine powder of silica and other metal oxide by using other metal halogen compound such as aluminum chloride and titanium chloride together with the silicon halogen compound in the manufacturing process. Also includes.

The inorganic fine powder used in the present invention is BET.
Nitrogen adsorption specific surface area measured is 30 m ² / g or more by law, in particular 50 to 400 m ² / g give good results in the range of, used 0.3 to 8 parts by mass relative to 100 parts by weight of the toner particles , Preferably 0.5 to 5 parts by mass.

By allowing the inorganic fine powder having a controlled specific surface area as described above to coexist with an oxycarboxylic acid existing in the vicinity of the toner surface, the amount of water adsorbed on the toner particles can be controlled, and the triboelectric charge amount and the charging speed can be controlled. The control effect is increased.
Further, image defects due to contamination of the toner carrier or the like with oxycarboxylic acid are prevented in advance. Further, since the toner is imparted with an appropriate fluidity, the uniform charging property of the toner is synergistically improved, and the above-described excellent effect is maintained even when a large number of printouts are continuously repeated.

When the nitrogen adsorption specific surface area is less than 30 m ² / g, it is difficult to impart appropriate fluidity to the toner, and it is possible to prevent the toner carrier from being contaminated by the oxycarboxylic acid. The effect becomes smaller. Further, when the nitrogen adsorption specific surface area exceeds 400 m ² / g, the inorganic fine powder is embedded in the surface of the toner particles during continuous printout, which may lower the fluidity of the toner.

If the addition amount of the inorganic fine powder is less than 0.3 part by mass, the effect of addition is not exhibited, and if it exceeds 8 parts by mass, problems occur in the charging property and fixing property of the toner. In addition, the loosened inorganic fine powder significantly deteriorates matching with the image forming apparatus.

The inorganic fine powder used in the present invention is
Silicone varnishes, various modified silicone varnishes, silicone oils, various modified silicone oils, silane coupling agents, silane coupling agents having functional groups, other organic silicon compounds, organics for the purpose of hydrophobicizing, controlling chargeability, etc. It is also possible and preferable to treat with a treating agent such as a titanium compound or in combination with various treating agents.

The nitrogen adsorption specific surface area of the inorganic fine powder was calculated by the BET multipoint method by adsorbing nitrogen gas on the sample surface using a specific surface area measuring device "Autosorb 1" (manufactured by Yuasa Ionics).

In order to maintain a high charge amount, achieve a low consumption amount and a high transfer rate, it is more preferable that the inorganic fine powder is treated with at least silicone oil.

In the toner of the present invention, other additives, for example, lubricant powders such as polyfluorinated ethylene powder, zinc stearate powder, and polyvinylidene fluoride powder; cerium oxide powder, Abrasives such as silicon carbide powder and strontium titanate powder;
For example, a fluidity-imparting agent such as titanium oxide powder and aluminum oxide powder; an anti-caking agent, or a conductivity-imparting agent such as carbon black powder, zinc oxide powder, tin oxide powder, and reverse polarity organic fine particles and inorganic fine particles. It can also be used in a small amount as a developability improver.

As a method for producing the toner according to the present invention, a binder resin, a colorant, a wax component and the like are melt-kneaded by a pressure kneader or the like, and then the cooled kneaded product is finely pulverized to a desired toner particle size. Further, a pulverization method in which a finely pulverized product is classified to adjust the particle size distribution to obtain a toner; JP-B-36-10231.
JP, JP-A-59-53856 and JP-A-59.
A method for directly producing a toner by using the suspension polymerization method described in JP-A-61842; JP-B-56-13945.
A method for producing a spherical toner by atomizing a melt-kneaded product into the air using a disk or a multi-fluid nozzle described in Japanese Patent Publication No. JP-A No. 2000-187; and a known method such as an emulsion polymerization method typified by a soap-free polymerization method Although it is possible, it is preferable to produce a toner in which the content state of oxycarboxylic acid is specified by the suspension polymerization method while controlling the pH in the aqueous dispersion medium during the polymerization reaction of the polymerizable vinyl monomer. .

By the way, the oxycarboxylic acid added to the toner for the purpose of controlling the triboelectric charge amount and the charging speed has a large number of hydrophilic functional groups, so that the polymerizable monomer in the aqueous dispersion medium is used. When the granulated particles of the composition are polymerized to form toner particles, elution of the oxycarboxylic acid into the aqueous medium occurs. When elution of oxycarboxylic acid occurs, the obtained toner particles do not sufficiently exhibit the effect of improving the charge amount and the charge speed. Further, since the eluted oxycarboxylic acid behaves like a surfactant, it becomes very difficult to maintain the shape of the toner particles in the polymerization step, and the toner cannot be controlled to have a desired particle size distribution or spherical distribution. In particular, when the amount of oxycarboxylic acid eluted is large, particles having a finer particle size smaller than the toner particles are produced as a by-product, which also interferes with matching with the image forming apparatus.

On the other hand, the present inventors prevent the elution of oxycarboxylic acid by controlling the polymerization conversion rate of the polymerizable vinyl monomer and the pH in the aqueous dispersion medium,
It has been found that the oxycarboxylic acid can be immobilized in a good state near the surface of the toner.

That is, in the polymerization reaction of the polymerizable monomer composition from the granulation step to the polymerization step, the pH in the aqueous dispersion medium was adjusted to 4 until the polymerization conversion rate of the polymerizable vinyl monomer reached 10% or more. Hold at 0.5-8.5. As a result, elution of the oxycarboxylic acid is prevented and the oxycarboxylic acid is encapsulated in the toner particles.

Furthermore, after the pH in the aqueous dispersion medium is readjusted to 9 to 13 and the polymerization conversion rate is further increased, the oxycarboxylic acid encapsulated in the toner can be involved in the triboelectric charging near the surface of the toner particles. At the same time as drawing out, the oxycarboxylic acid existing on the surface can be dissolved and removed in an alkaline atmosphere.

As described above, it becomes possible to immobilize the oxycarboxylic acid in the vicinity of the surface of the toner particles in a good condition, and the resulting toner has very good charging characteristics. In addition, since the particle size distribution and shape distribution of the toner particles can be controlled to desired ones without causing by-products of fine particle diameters, the charging characteristics are synergistically improved, and it is possible to improve the image forming apparatus. Matching can be very good. In particular, by carrying out the polymerization reaction of the polymerizable vinyl monomer while maintaining the pH in the aqueous medium at 4.5 to 6.0, the encapsulating property of the oxycarboxylic acid is further enhanced, so that the above-described improving effect is further improved. It will be good.

Further, when the toner of the present invention is produced, the pH in the aqueous dispersion medium and the pH in the aqueous dispersion medium are adjusted so that the oxycarboxylic acid amount A and the oxycarboxylic acid amount B satisfy the above relationship. The polymerization conversion rate of the polymerizable vinyl monomer in the polymerizable monomer composition at the time of switching is appropriately adjusted.

In the present invention, the "polymerization conversion rate" of the polymerizable vinyl-based monomer means the total mass (W ₁ ) of the polymerizable vinyl-based monomer used in the polymerizable monomer composition. Based on the total mass of unreacted polymerizable vinyl-based monomer (W
₂ ) can be calculated from the following formula by quantifying.

[0191]

[Equation 4]

The unreacted polymerizable vinyl monomer is
Immediately after sampling from the reaction container, a polymerization terminator, cold methanol, etc. are added to the sample to stop the polymerization reaction, and thermogravimetric measurement (TG) is used to measure the amount of mass loss during heating with a thermobalance or the like. The method can be carried out by applying a known method such as a method using gas chromatography (GC). Among these, the method using GC is useful.

In the present invention, the unreacted polymerizable vinyl-based monomer is quantified under the following conditions.

<GC measurement conditions> Apparatus: GC-14A (manufactured by Shimadzu Corporation) Column: Fused silica capillary column (J & W SC
Made by IENTIFC; size ... 30m × 0.249m
m, liquid phase ... DBWAX, film thickness ... 0.25 μm) Sample: 2.55 mg of DMF as an internal standard, 10
Make solvent with internal standard by adding 0 ml of acetone. Next, 400 mg of toner is made into a 10 ml solution with the above solvent. After ultrasonically shaking for 30 minutes, leave it for 1 hour. Then, filter with a 0.5 μm filter. The amount of sample to be implanted is 4 μl. Detector: FID (split ratio: 1:20) Carrier gas: N ₂ gas Oven temperature: 70 ° C. → 220 ° C. (Wait at 70 ° C. for 2 minutes, then raise the temperature at a rate of 5 ° C./minute) Inlet temperature: 200 ° C. Detector temperature: 200 ° C. Preparation of calibration curve: Gas chromatograph measurement was similarly performed on a standard sample prepared by adding the polymerizable vinyl monomer of interest to the DMF and acetone solution similar to the sample solution, and the polymerizable vinyl series was used. The mass ratio / area ratio of the monomer and the internal standard DMF is determined.

In the production of the toner of the present invention, as the dispersant used when preparing the aqueous dispersion medium, known inorganic and organic dispersants can be used. Specifically, as the inorganic dispersant, for example, tricalcium phosphate, magnesium phosphate, aluminum phosphate,
Examples thereof include zinc phosphate, magnesium carbonate, calcium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica and alumina. Further, as the organic dispersant, for example, polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, starch and the like can be used.

Commercially available nonionic, anionic and cationic surfactants can also 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 can be used.

In the production of the toner of the present invention, an inorganic sparingly water-soluble dispersant is preferable, and a sparingly water-soluble inorganic dispersant which is soluble in an acid may be used. In addition, in the present invention, when an aqueous dispersion medium is prepared using a poorly water-soluble inorganic dispersant, the amount of the poorly water-soluble inorganic dispersant is 0.2 to 100 parts by mass of the polymerizable vinyl-based monomer. It is preferable to prepare 2.0 parts by mass, and it is preferable to prepare the aqueous dispersion medium using 300 to 3,000 parts by mass of water with respect to 100 parts by mass of the polymerizable monomer composition.

In the present invention, when an aqueous dispersion medium in which the poorly water-soluble inorganic dispersant as described above is dispersed is prepared, a commercially available dispersant may be used as it is, but a fine uniform particle size may be used. In order to obtain the dispersant particles having the above, the poorly water-soluble inorganic dispersant as described above may be prepared in a liquid medium such as water under high speed stirring. For example, when using tricalcium phosphate as a dispersant,
A preferable dispersant can be obtained by mixing an aqueous sodium phosphate solution and an aqueous calcium chloride solution under high-speed stirring to form fine particles of tricalcium phosphate.

According to the method for producing a toner having the above-mentioned structure, the friction charge amount under high humidity and the friction under low humidity, which have been conventionally found in toners containing a charge control agent, are reduced. It is possible to easily obtain a toner in which the decrease in the charging speed is suppressed and the occurrence of the transfer failure of the toner image can be effectively suppressed.

Next, the polymerizable monomer composition used in the production of the toner according to the present invention will be described. The polymerizable monomer composition contains at least a polymerizable vinyl-based monomer, a colorant, a charge control agent, and an oxycarboxylic acid, preferably, in addition to this, a wax component, and if necessary, various additives. It is prepared by dissolving and mixing substances.

As the polymerizable vinyl-based monomer used at this time, the polymerizable monomers described above are appropriately mixed and used so that the theoretical glass transition temperature (Tg) is 40 to 75 ° C. To be In particular, when Tg is high, when a color toner for forming a full-color image is manufactured, the color mixing property of each color toner at the time of fixing is lowered, the color reproducibility is poor, and the transparency of the OHP image is lowered. It is not preferable because

Specific examples of the polymerization initiator used for producing the toner according to the present invention include 2,2'-azobis- (2,4-dimethylvaleronitrile) and 2,2'-azobisiso. Butyronitrile, 1,1, -azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile,
Azo- or diazo-type polymerization initiators such as azobisisobutyronitrile; peroxide-type polymerization initiators such as benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide Is used. The amount of these polymerization initiators used varies depending on the intended degree of polymerization, but is generally 5 to 20 parts by mass with respect to 100 parts by mass of the polymerizable vinyl-based monomer. The type of polymerization initiator varies slightly depending on the polymerization method, but with reference to the 10-hour half-life temperature,
Used alone or as a mixture.

In the polymerizable monomer composition, in order to control the degree of polymerization, known crosslinking agents, chain transfer agents, polymerization inhibitors and the like may be further added and used. These additives can be added to the polymerizable monomer composition in advance, or can be appropriately added during the polymerization reaction, if necessary.

[0204]

EXAMPLES The present invention will be described below with reference to specific examples, but the present invention is not limited thereto.

(Toner Production Example 1) 700 g of ion-exchanged water and 0.1 g of deionized water were placed in a 2-liter four-necked flask equipped with a high-speed stirrer Clearmix (manufactured by M Technique Co., Ltd.).
It was charged mol / L-Na ₃ PO ₄ aqueous solution 800 g, to set the rotational speed of the high-speed stirrer to 15000 rpm, 70 ° C.
It was heated to. 1.0 mol / L-CaCl ₂ here
70 parts by mass of an aqueous solution is added, and a minute sparingly water-soluble dispersant Ca
_An aqueous dispersion medium containing ₃ (PO ₄ ) ₂ was prepared. Further, it was re-prepared with dilute hydrochloric acid so that the pH of the aqueous dispersion medium became 5.5.

On the other hand, as dispersoids: styrene monomer 83 parts by mass, n-butyl acrylate monomer 17 parts by mass, divinylbenzene monomer 0.3 parts by mass, carbon black (BET specific surface area = 45 m ² / g) 6 parts by mass polyester resin (acid value = 20 mg KOH / g) 2 parts by mass charge control agent 1 part by mass [charge control resin: styrene-2-acrylamido-2-methylpropanesulfonic acid copolymer copolymerization ratio ( Mass%) = 85:15, Tg = 65 ° C.] 1 part by mass of the oxycarboxylic acid (1-A) / ester wax (melting point = 60 ° C.) 7 parts by mass of an attritor (manufactured by Mitsui Kinzoku Co., Ltd.) Was dispersed for 3 hours, and then 3 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was added to prepare a polymerizable monomer composition.

Then, the polymerizable monomer was added to the aqueous dispersion medium.
The body composition is added, and the internal temperature is 70 ° C. ₂Fast in the atmosphere
While maintaining the rotation speed of the stirring device at 15000 rpm, 1
The mixture was stirred for 0 minute to granulate the polymerizable monomer composition. That
After that, change the stirring device to one equipped with paddle stirring blades,
While maintaining the same temperature while stirring at 200 rpm,
When the polymerization conversion rate of the nil monomer reached 95%
Aqueous dispersion by adding 0.1 mol / L NaOH aqueous solution
The pH of the medium was changed to 11. Furthermore, the reaction temperature was raised to 85 ° C.
When the temperature rises and the polymerization conversion rate becomes almost 100%,
The combined reaction was completed.

After completion of the polymerization, the residual monomer was distilled off under heating and reduced pressure, and after cooling, dilute hydrochloric acid was added to dissolve the hardly water-soluble dispersant. After repeating water washing several times,
A conical ribbon dryer (manufactured by Okawara Seisakusho Co., Ltd.) was used to perform a drying treatment to obtain polymer particles (A).

100 parts by mass of the polymer particles (A) and a silica fine powder treated with a hydrophobic oil (BET: 200 m ² / g)
Toner (A) was obtained by dry-mixing 2 parts by mass with a Henschel mixer (manufactured by Mitsui Kinzoku Co., Ltd.).

The amount A of oxycarboxylic acid extracted with methanol from 1 g of the toner (A) was 1.82 mg /
The amount of oxycarboxylic acid B extracted with 0.1 mol / L sodium hydroxide aqueous solution is 1.45 mg / g.
In g, the A / B value was 1.26 and the (3/4) B + 1 value was 2.09.

The circle-equivalent number average diameter is 5.5 μm,
In the circularity frequency distribution, the average circularity was 0.985, the circularity standard deviation was 0.020, and the number of toner particles having a circularity of less than 0.95 was 3.7% by number.

Further, when the tomographic plane of the toner (A) was observed by TEM, a continuous thin layer was formed on the surface of the toner particles as shown in the schematic view of FIG. The binder resin and the wax component were present, and the value of (r / R) _st was 0.33.

(Toner Production Examples 2 to 6) The types and addition amounts of the oxycarboxylic acid, the charge control agent, and the wax component are changed, and the pH of the aqueous dispersion medium during the polymerization reaction during the production of the toner and the pH switching are performed. Polymer particles (B) to (F) were obtained in the same manner as in the toner production example 1 except that the polymerization conversion rate was changed, and then the toners (B) to (F) were obtained.
Was prepared.

(Production Examples 1 and 2 of Comparative Toner) The types and addition amounts of the oxycarboxylic acid, the charge control agent, and the wax component were changed, and the pH of the aqueous dispersion medium during the polymerization reaction during the production of the toner, and Comparative polymer particles (a) and (b) were obtained in the same manner as in the toner production example 1 except that the polymerization conversion rate at the time of pH switching was changed, and then the comparative toners (a) and (b) were obtained. Was prepared.

In the observation of the tomographic planes of the comparative toners (a) and (b) by TEM, formation of a thin layer on the surface of the toner particles was not confirmed, and the dispersed state of the wax component is shown in the schematic diagram of FIG. 4 (b). As described above, they were substantially spherical and dispersed in the binder resin, and the value of (r / R) _st was less than 0.05.

The types and amounts of the oxycarboxylic acid, the charge control agent, and the wax component used in the above-mentioned toner production examples and comparative toner production examples, and the pH conditions of the aqueous dispersion medium, and the toner obtained The various properties of are shown in Tables 1 and 2.

[0217]

[Table 1]

[0218]

[Table 2]

(Toner Production Example 7) 700 parts by mass of ion-exchanged water and 0.1 mol / L-Na ₃ PO were placed in a 2-liter four-necked flask equipped with a high-speed stirrer CLEARMIX (manufactured by M Technique Co., Ltd.). ₄ 800 parts by mass of the aqueous solution was added, the rotation speed of the high-speed stirring device was set to 15000 rpm, and the mixture was heated to 65 ° C. 1.0 mol / L-
70 parts by mass of an aqueous CaCl ₂ solution was added to prepare an aqueous dispersion medium containing a minute sparingly water-soluble dispersant Ca ₃ (PO ₄ ) ₂ . Further, it was re-prepared with diluted hydrochloric acid so that the pH of the aqueous dispersion medium became 5.5.

On the other hand, as dispersoids: styrene monomer 77 parts by mass, 2-ethylhexyl acrylate monomer 23 parts by mass, divinylbenzene monomer 0.2 parts by mass, carbon black (DBP oil absorption = 75 ml / 100 g) ) 5 parts by mass Polyester resin (acid value = 15 mgKOH / g) 2 parts by mass (condensation polymer of epoxidized bisphenol A and isophthalic acid, Tg = 70 ° C.) Unsaturated polyester resin 1 part by mass (with epoxidized bisphenol A) Fumaric acid condensation polymer, Tg = 65 ° C.) Charge control agent 1 part by mass [charge control resin: styrene-2-acrylamido-2-methylpropanesulfonic acid copolymer Copolymerization ratio (wt%) = 80:20 , Tg = 60 ° C.] 1 part by mass of the oxycarboxylic acid (1-A) Ester wax (melting point = 65 ° C.) 10 parts by mass After dispersing the mixture consisting of 3 to 3 with an attritor (Mitsui Kinzoku Co., Ltd.), 3 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) is added to the polymerizable monomer composition. Was prepared.

Next, the polymerizable monomer is added to the aqueous dispersion medium.
The body composition is added and the internal temperature is 65 ° C. ₂Fast in the atmosphere
While maintaining the rotation speed of the stirring device at 15000 rpm, 1
The polymerizable monomer composition was granulated by stirring for 5 minutes. That
After that, change the stirring device to one equipped with paddle stirring blades,
While maintaining the same temperature while stirring at 80 rpm,
No. 1 when the polymerization conversion rate of vinyl monomer reached 95%
The reaction process was completed. 0.1 mol / L of NaO
H aqueous solution was added to change the pH of the aqueous dispersion medium to 10.
It was Furthermore, the reaction temperature was raised to 85 ° C, and the polymerization conversion rate was almost
When 100% is reached, the second reaction step is completed and polymerization
The process is complete.

After the completion of the polymerization, polymer particles (G) were obtained in the same manner as in Production Example 1 of the above toner.

100 parts by mass of the above polymer particles (G) and hydrophobic
Silica fine powder (BET: 200m ²/ G) 1.5 mass
Part and hydrophobic titanium oxide fine powder (BET: 50m²/ G)
0.5 parts by mass with a Henschel mixer (Mitsui Kinzoku Co., Ltd.)
Toner (G) was obtained by dry mixing.

Oxycarboxylic acid content A extracted with methanol from 1 g of the toner (G) was 1.67 m.
The amount of oxycarboxylic acid B extracted with a 0.1 mol / L sodium hydroxide aqueous solution is 1.19 m in g / g.
The value of A / B is 1.40 in g / g, and (3/4) B + 1
The value of was 1.89.

The circle-equivalent number average diameter is 5.6 μm,
In the circularity frequency distribution, the average circularity was 0.988, the circularity standard deviation was 0.019, and the number of toner particles having a circularity of less than 0.95 was 2.5% by number.

Further, when the tomographic plane of the toner (G) was observed by TEM, a continuous thin layer was formed on the surface of the toner particles as shown in the schematic view of FIG. The binder resin and the wax component were present, and the value of (r / R) _st was 0.36.

(Toner Production Examples 8 to 13) The types and amounts of the oxycarboxylic acid, the charge control agent, and the wax component were changed, and the pH of the aqueous dispersion medium during the polymerization reaction during the production of the toner and the pH switching were performed. Polymer particles (H) to (M) were obtained in the same manner as in the toner production example 7 except that the polymerization conversion rate was changed.
(M) was prepared.

(Production Examples 3 and 4 of Comparative Toner) The types and addition amounts of the oxycarboxylic acid, the charge control agent, and the wax component were changed, and the pH of the aqueous dispersion medium during the polymerization reaction during the production of the toner, and Comparative polymer particles (c) and (d) were obtained in the same manner as in the toner production example 7 except that the polymerization conversion rate at the time of pH switching was changed, and then the comparative toners (c) and (d) were obtained. Was prepared.

The types and addition weights of the colorant, charge control agent, oxycarboxylic acid, and wax components used in the above-mentioned toner production examples and comparative toner production examples, and the pH conditions of the aqueous dispersion medium, and Various properties of the obtained toner are summarized in Tables 3 and 4.

[0230]

[Table 3]

[0231]

[Table 4]

(Production Example 1 of Elastic Blade) 12-nylon carboxylated with dodecanedioic acid as a polyamide component and polytetramethylene glycol as a polyether component were used to carry out condensation polymerization to obtain a polyamide elastomer. After drying for a predetermined time, a melting temperature of 200
C / mold temperature of 30 ° C. is directly molded by injection molding into a mold equipped with a 0.1 mm thick metal thin plate made of phosphor bronze that exhibits spring elasticity in advance, and a thickness of 1 m on the thin metal plate.
A blade 1 having an elastic body of polyamide elastomer of m was prepared.

Shore D of the elastic body of the obtained blade 1
The hardness was 25 °.

(Production Examples 2 to 5 of Elastic Blade and Production Examples 1 and 2 of Comparative Blade) Blade 2 having different Shore D hardness is the same as Production Example 1 of the elastic blade except that the production conditions are changed. ~ 5, and comparative blade 1
And 2 were manufactured.

The elastic bodies of the obtained blades 2 to 5 had Shore D hardnesses of 30 °, 45 °, 50 ° and 65 °, respectively, and the Shore D hardnesses of the comparative blades 1 and 2 were 20 ° and 70 °.
Met.

(Production Example 3 of comparative blade) Thickness 0.1
A 1 mm-thick urethane sheet (Shore D hardness = 30 °) molded and processed by a centrifugal molding machine as an elastic body was adhered to a thin metal plate made of phosphor bronze having a thickness of mm to prepare a comparative urethane blade.

(Production Example 6 of elastic blade) A die having a mirror surface with a preheated vent mechanism was used, and SUS having a thickness of 60 μm was used.
After a metal thin plate made of azodicarbonamide was installed, a polyamide elastomer to which an azodicarbonamide foaming agent was added and mixed was injected to form a foamed polyamide elastomer foam with a skin layer on which a mirror surface was transferred.

After further heat treatment, secondary processing was performed into the shape of an elastic blade. That is, the distance NE from the contact portion with the developing roller to the free end is continuously shortened from the central portion of the elastic blade to both ends, and the tip position of the free end is different from the developing roller at both end portions. The blade 6 was manufactured by processing so as to fit in the abutting part.

The Shore D hardness of the obtained blade 6 is 2
It was 5 °.

(Production Examples 7 and 8 of Elastic Blade, and Production Examples 4 and 5 of Comparative Blade) Blade 7 having a different Shore D hardness is the same as Production Example 6 of the elastic blade except that the production conditions are changed. And 8, and comparative blade 4
And 5 were manufactured.

The Shore D hardnesses of the obtained blades 7 and 8 were 50 ° and 65 °, respectively, and the Shore D hardness of the comparative blades 4 and 5 were 20 ° and 70 °.

Example 1 A commercially available laser beam printer was modified to prepare the image forming apparatus shown in FIG. 1 according to the above-mentioned specific example, and the image forming conditions were set so as to satisfy the following developing conditions. Photoconductor dark area potential (Vd): -800V Photoconductor light area potential (Vl): -100V Development bias voltage: -400V (DC component only)

For the toner regulating member, the blade 3 (Shore D hardness =
45 °) and the contact pressure with the developing roller is 0.29N
It was adjusted to be (30 g).

An elastic roller having a foamed skeletal sponge structure is used as the toner applying roller 6, is arranged so as to have a contact width of 2 mm with the developing roller 5, and the surface moving speed of the developing roller (216 mm / sec. , The peripheral speed ratio to the surface moving speed of the photoconductor drum = 150%) 70
The peripheral speed ratio was set to be rotationally driven in the opposite direction (direction of arrow D in FIG. 2).

The toner (A) obtained in the toner manufacturing example 1 is sequentially replenished to the process cartridge of the image forming apparatus, and the printout speed is 24 sheets / minute (A4 size paper) under the normal temperature and normal humidity environment. A printout test for 5,000 sheets was performed.

The obtained print-out image was excellent in image density, image scattering, image ghost, image fog, and dot reproducibility.

Furthermore, the above toner (A) is added at 40 ° C./85%
When the same printout test was performed again after leaving it for 1 week in a high temperature and high humidity environment, a good printout image could be obtained again.

After the print-out test, the toner application state on the developing roller was observed, and it was confirmed that a uniform thin layer of toner was formed.

The evaluation items and the evaluation criteria are as follows, and the same evaluation was performed in Examples 2 to 6 and Comparative Examples 1 to 6 described later.

[Evaluation of Printout Image] <1> Image Density Evaluation was made based on the image density when a predetermined number of printouts were completed on a normal copying machine plain paper (75 g / m ² ). The image density is "Macbeth reflection densitometer RD918".
(Manufactured by Macbeth Co., Ltd.) was used to measure the relative density of a white background portion having a document density of 0.00 with respect to a printout image. A: 1.40 or more B: 1.35 or more, less than 1.40 C: 1.00 or more, less than 1.35 D: less than 1.00

<2> Image Scattering The “electrical” character pattern shown in FIG.
The toner scattering (state in FIG. 5B) to the peripheral portion of the character when printed out at g / m ² ) was visually evaluated. A: Almost no occurrence. B: Minor scattering is seen. C: Some scattering is seen. D: Remarkable scattering is seen.

<3> Image ghost A solid black strip image X of width a and length l shown in FIG. 6 (A).
After printing out, the width b (>
When a halftone image Y having a length of 1 is printed out in a), the grayscale difference appearing on the halftone image (see FIG. 6).
The portions (A, B, and C of (C)) were visually evaluated. A: No gray level difference is observed B: Minor gray level difference is observed between B and C C: A, B, and C are slightly gray level differences D: Significant gray level difference is seen

<4> Image fog solid image When a white image is formed, the transfer residual toner on the photoconductor is taped off with Mylar tape and peeled off.
918 ". Evaluation was performed using the numerical value obtained by subtracting the reflection density when the Mylar tape was directly attached to the paper from the obtained reflection density. The smaller the value, the more the image fogging is suppressed. A: less than 0.03 B: 0.03 or more, less than 0.07 C: 0.07 or more, less than 0.15 D: 0.15 or more

<5> Dot Reproducibility An image of an isolated dot pattern having a small diameter (45 μm) as shown in FIG. 7 was printed out and the dot reproducibility was evaluated by closing the electric field due to the latent image electric field and making it difficult to reproduce. A: 2 or less defects in 100 B: 3 to 5 defects in 100 C: 6 to 10 defects in 100 D: 11 or more defects in 100

[Matching Evaluation of Image Forming Apparatus] <1> State of Forming Thin Layer of Toner on Developing Roller After completion of the printout test, state of forming thin layer of toner on the developing roller was visually evaluated. A: A uniform thin layer of toner is formed. B: There is slight unevenness, but there is no effect on the image. C: Streaky coat unevenness occurs in the rotating direction, and the image is also affected. D: It is difficult to form a uniform thin layer of toner, and toner is scattered from the developing roller.

<2> Matching with Toner Coating Roller After completion of the printout test, the state of toner adhesion to the toner coating roller and the influence on the printout image were visually evaluated. A: No sticking occurred. B: Contamination occurs, but sticking hardly occurs. C: There is sticking, but the effect on the image is small. D: Much sticking and image unevenness occur.

The evaluation results are summarized in Table 5.

Example 2 When evaluated in the same manner as in Example 1 except that the toner (B) obtained in Toner Production Example 2 was used as the toner, generally good results were obtained.

The evaluation results are summarized in Table 5.

<Embodiments 3 to 6> Toners (C) to (F) are used as toners, and the type of elastic blade and the setting of the peripheral speed ratio of the toner applying roller to the surface moving speed of the developing roller are changed. When evaluated in the same manner as in Example 1 except that, almost good results were obtained.

The evaluation results are summarized in Table 5.

<Comparative Examples 1 and 2> Evaluations were made in the same manner as in Example 1 except that comparative toners (a) and (b) were used as toners.

As a result, good results could not be obtained because the content and existing state of the oxycarboxylic acid in the toner were not controlled to a specific state.

The evaluation results are summarized in Table 5.

Comparative Examples 3 and 4 Similar to Example 1 except that the comparative toners (a) and (b) were used as toners and the elastic blades were changed to comparative blades 2 and 1, respectively. evaluated.

As a result, good results could not be obtained because the content and existing state of the oxycarboxylic acid in the toner were not controlled to a specific state.

Further, since the Shore D hardness of the elastic blade was not appropriate, the thin layer formation state of the toner was not sufficient.

The evaluation results are summarized in Table 5.

Comparative Example 5 The same evaluation as in Example 6 was conducted except that the toner (F) was used as the toner and the elastic blade was changed to the urethane blade for comparison.

As a result, good results could not be obtained because the content and existing state of the oxycarboxylic acid in the toner were not controlled to a specific state.

Further, since the material of the elastic blade was not appropriate, the thin layer formation state of the toner was not sufficient.

The results of these evaluations are summarized in Table 5.

[0273]

[Table 5]

Example 7 A commercially available full-color copying machine was modified to prepare the image forming apparatus shown in FIG. 3 according to the above-described specific example.

The developing device 4 shown in FIG. 1 was used as the developing device, and the image forming conditions were set so as to satisfy the following developing conditions and transfer conditions. Photoconductor dark area potential (Vd): -750V Photoconductor light area potential (Vl): -50V Development bias voltage: -350V (DC component only) Transfer bias voltage applied to the intermediate transfer body in the first transfer step: 300V ( DC component only) Transfer bias voltage applied to the transfer roller in the second transfer step: 1000 V (DC component only)

The cleaner 63 was removed so that the residual toner remaining on the photosensitive drum could be collected by the developing device.

For the toner regulating member, the blade 7 (Shore D hardness =
50 °) and the contact pressure with the developing roller is 0.245.
It was adjusted to be N (25 g).

The elastic roller used in the above-described Example 1 is diverted to the toner applying roller 6, and it is arranged so as to have a contact width of 3 mm with respect to the developing roller 5, and the surface moving speed of the developing roller (144 mm / Sec, the peripheral speed ratio to the surface moving speed of the photosensitive drum = 150%), 60%
The peripheral speed ratio was set to rotate in the opposite direction (the direction of arrow D in FIG. 2).

The process cartridge of the above image forming apparatus is successively replenished with the toner (G) obtained in Toner Production Example 7 and printed at 16 sheets / minute (A4 size paper) in the monochrome mode under the normal temperature and normal humidity environment. 5000 out speed
A printout test for one sheet was performed.

The obtained printout image was excellent in image density, image ghost, image fog, and dot reproducibility. In addition, image contamination due to poor charging of the photoconductor drum did not occur, toner adhesion to the charging roller was slight, and recovery of the transfer residual toner remaining on the photoconductor drum was good.

Furthermore, the above toner (A) is added at 40 ° C./85%
When the same printout test was performed again after leaving it for 1 week in a high temperature and high humidity environment, a good printout image could be obtained again.

After the completion of the printout test, the toner application state on the developing roller was observed, and it was confirmed that a uniform thin layer of toner was formed.

The description of the evaluation items and the evaluation criteria are as follows, and the same evaluation was made in Examples 8 to 13 and Comparative Examples 5 to 8 described later.

[Evaluation method] <1> Image density According to the case shown in Table 5.

<2> Image Staining Image smearing when a halftone image composed of 1 dot line and 1 dot space was printed out on plain paper (75 g / m ² ) was visually evaluated. A: Not generated B: Minor stains are seen C: Fine black dot stains are seen D: Periodic band-like stains or vertical stripe-like stains are seen

<3> Image ghost According to the case shown in Table 5.

<4> Image ghost According to the case shown in Table 5.

<5> Dot reproducibility According to the case shown in Table 5.

[Image forming apparatus matching evaluation] <1> Forming state of thin layer of toner on developing roller According to the case shown in Table 5.

<2> Amount of Toner Attached to Charging Roller The mass of toner (mg / cm ² ) per unit area attached to the surface of the charging roller was measured. The smaller the toner adhesion amount, the better. A: 0.20mg / cm ² less B: 0.20mg / cm ² or more, 0.35 mg / cm ² less than C: 0.35mg / cm ² or more, 0.55 mg / cm ² less than D: 0.55 mg / cm ² or more

The results of these evaluations are summarized in Table 6.

<Embodiments 8 to 13> Toners (H) to (M) are used as toners, and the type of elastic blade and the setting of the peripheral speed ratio of the toner applying roller to the surface moving speed of the developing roller are changed. When evaluated in the same manner as in Example 7 except that, almost good results were obtained.

The evaluation results are summarized in Table 6.

Comparative Examples 5 and 6 Evaluations were made in the same manner as in Example 7 except that comparative toners (c) and (d) were used as the toners.

As a result, good results could not be obtained because the content and existing state of the oxycarboxylic acid in the toner were not controlled to a specific state.

The results of these evaluations are summarized in Table 6.

Comparative Examples 7 and 8 Same as Example 1 except that comparative toners (a) and (b) were used as toners and the elastic blades were changed to comparative blades 5 and 4, respectively. evaluated.

As a result, good results could not be obtained because the content and existing state of the oxycarboxylic acid in the toner were not controlled to a specific state.

Since the Shore D hardness of the elastic blade was not appropriate, the thin layer formation state of the toner was not sufficient.

The results of these evaluations are summarized in Table 6.

[0301]

[Table 6]

<Embodiment 14> Toner (G) as toner
And (I) to (K) were used, and evaluation was performed in the same manner as in Example 7 except that 5000 graphic images were printed out in the full color mode. During the print-out test, the image forming apparatus repeats the pause and the start every time 50 sheets are continuously printed, so that the toner adhering to the charging roller may be collected by the developing device during the preliminary operation at the time of restart. Set.

The obtained print-out image was a good full-color image excellent in image density and image fog and free from uneven image density and uneven color reproduction. In addition, image contamination due to poor charging of the photoconductor drum did not occur, toner adhesion to the charging roller was slight, and recovery of the transfer residual toner remaining on the photoconductor drum was good.

[0304]

As described above, according to the image forming method of the present invention, the developing device is provided with the toner regulating member using the polyamide resin or the polyamide-containing elastomer having the Shore D hardness of 25 to 65 degrees. On the other hand, by using a toner with a specified content of oxycarboxylic acid, a uniform thin layer of toner can be formed on the toner carrier and good charging can be achieved. It is possible to reduce image deterioration and perform high-resolution and high-definition image formation even under severe usage conditions such as starting.

Further, when the developing / cleaning system is used, more stable recovery of the transfer residual toner on the photosensitive member can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of an image forming apparatus having a process cartridge using a contact one-component developing device as an example of an image forming method of the present invention.

FIG. 2 is an enlarged view of a developing device of the image forming apparatus.

FIG. 3 is a schematic view of an image forming apparatus including an intermediate transfer member using a contact one-component developing device as another example of the image forming method of the present invention.

FIG. 4 is a schematic diagram showing an example of a cross section of toner particles encapsulating a wax component.

FIG. 5 is a schematic diagram showing a scattered state of character images.

FIG. 6 is an explanatory diagram of an image ghost.

FIG. 7 is an explanatory diagram of an isolated dot pattern for evaluating resolution.

[Explanation of symbols]

1 Photoconductor drum (electrostatic latent image carrier) 2 charging roller 3 Laser light (exposure means) 4 Developing device 5 Development roller (toner carrier) 6 Toner application roller 7 Toner regulation blade 8 toner 9 Transfer roller 10 Cleaning blade (cleaning member) 11 Waste toner container

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/08 504 G03G 9/08 344 507 15/08 507B 507C 507L F term (reference) 2H005 AA06 AA15 CA04 CA14 CA30 DA01 EA03 EA05 EA07 FA07 2H073 AA02 BA02 BA13 CA02 2H077 AB04 AB14 AC04 AD02 AD06 AD13 AD18 AD23 AD31 AD35 AE04 EA15 FA13 FA22 FA25 GA13

Claims (14)

[Claims] 1. At least (a) a charging step of charging an image carrier for carrying an electrostatic latent image; (b) an exposure step of forming an electrostatic latent image on the charged image carrier by imagewise exposure;
(C) a developing step of developing the electrostatic latent image with toner contained in a developing device to form a toner image; (d) transferring the toner image formed on the surface of the image carrier through an intermediate transfer body. Or a non-intermediate transfer step of transferring to a transfer material; and (e) a cleaning step of cleaning and removing the toner remaining on the surface of the image bearing member after the transfer step; (1) toner applying means for supplying toner to the surface of the toner carrier by means of a toner applying roller arranged in contact with the surface of the toner carrier; and (2) on a surface of the thin plate having spring elasticity that contacts the toner. A thin layer of toner is formed on the surface of the toner carrier by a toner regulating member to which a polyamide resin or a polyamide-containing elastomer having a Shore D hardness of 25 degrees to 65 degrees is adhered or molded. A toner layer forming means that,
(3) A developing means for achieving the formation of a toner image by bringing the toner layer into contact with the surface of an image carrier, wherein the toner contains at least a binder resin, a colorant, a wax component, and an oxycarboxylic acid. Then, the mass A (mg) of oxycarboxylic acid extracted with methanol from 1 g of the toner and the mass B (mg) of oxycarboxylic acid extracted with a 0.1 mol / L sodium hydroxide aqueous solution are A / B = 1.05 to 3.00 B = 0.10 to 3.50 mg (based on toner mass). 2. Mass A (mg) of oxycarboxylic acid extracted with methanol from 1 g of toner and 0.1 m
The image forming method according to claim 1, wherein the mass B (mg) of the oxycarboxylic acid extracted by the ol / L sodium hydroxide aqueous solution satisfies A ≦ (3/4) B + 1. 3. The image forming method according to claim 1, wherein the oxycarboxylic acid is a compound represented by the following formula (1). [Chemical 1] (In the above formula (1), (A) is selected from the following group and X ₁
Represents a hydrogen atom, sodium atom, potassium atom, ammonium or aliphatic ammonium. ) [Chemical 2] 4. The image forming method according to claim 1, wherein the oxycarboxylic acid is a compound represented by the following formula (2). [Chemical 3] (In the formula (2), X ₂ represents a hydrogen atom, a sodium atom, a potassium atom, ammonium, or an aliphatic ammonium, and R ₄ represents a C _{1 to} C ₂₂ alkyl group, an alkenyl group, or an aryl group. , R ₅ is a hydrogen atom, C ₁ -C
_{22 represents} an alkyl group, an alkenyl group, an aryl group or an alkoxy group. ) 5. 2-Acrylamido-2-methylpropanesulfonic acid as a charge control agent in a copolymerization ratio of 2% by mass.
5. A toner containing the above, containing a charge control resin composed of styrene and / or styrene (meth) acrylic acid copolymer having a glass transition temperature (Tg) of 40 to 70 [deg.] C. is used. The image forming method according to any one of 1. 6. In the developing step, the surface moving speed of the toner applying roller provided in the developing device is set to a peripheral speed ratio of 30 to 90% with respect to the surface moving speed of the toner carrier, and the toner carrying roller is provided. 6. The image forming method according to claim 1, wherein a developing bias voltage of only a direct current component whose constant voltage is controlled is externally applied to the body. 7. The image forming method according to claim 1, wherein the method of collecting the transfer residual toner in the cleaning step is a developing / cleaning method which is also performed by the developing device in the developing step. Method. 8. In a toner number-based circle-equivalent diameter-circularity scattergram measured by a flow-type particle image measuring device, the toner has a circle-equivalent number average diameter D ₁ (μm) of 2
And the average circularity of the toner is 0.
The image forming method according to claim 1, wherein the circularity standard deviation is 920 to 0.995 and less than 0.040. 9. The average circularity of the toner is 0.950 to.
9. The image forming method according to claim 8, wherein the circularity standard deviation is 0.995 and is less than 0.035. 10. An average circularity of the toner is 0.970 to.
0.990, circularity standard deviation 0.015 or more 0.0
The image forming method according to claim 8, which is less than 35. 11. In a scattergram of circle-equivalent diameter-circularity based on the number of toner particles measured by the flow type particle image measuring device, the toner particles having a circularity value of less than 0.950 are 15% by number or less. The image forming method according to any one of claims 1 to 10, wherein: 12. A transmission electron microscope (TEM) of the toner.
In observing the tomographic plane of toner particles using (1) Weight of toner measured by a flow type particle image measuring device
0.9 for the weight-based average diameter D4 (μm)
Presents a major axis R (μm) that satisfies the relationship of ≦ R / D4 ≦ 1.1
Select 20 tomographic planes of toner particles to (2) Watts existing in the tomographic plane of the selected toner particles
Of the largest phase separation structure due to the
Measure the major axis r, (3) Calculated arithmetic mean value (r / R) of r / R_stBut,
0.05 ≦ (r / R) _stTo satisfy ≦ 0.95
The wax component is substantially spherical and / or spun in the binder resin.
The particles are dispersed in a cone-shaped island shape.
12. The image forming method according to any one of 1 to 11. 13. The arithmetic mean value (r / R) _{st of the} r / R
However, the wax component is dispersed in the binder resin in a substantially spherical and / or spindle-shaped island shape so as to satisfy 0.25 ≦ (r / R) _st ≦ 0.90. The image forming method according to claim 12. 14. In observation of a tomographic plane of a toner particle using a transmission electron microscope (TEM), the surface of the toner particle is subjected to electronic staining with ruthenium tetroxide (RuO ₄ ) and / or osmium tetroxide (OsO ₄ ). A thin layer of a material identified by the method is formed, a binder resin and a wax component are present in the toner inward direction, and the wax component is substantially spherical and / or spindle-shaped islands in the binder resin. 14. The particles are dispersed in a uniform shape.
The image forming method according to any one of 1.