JP2003107904A - Developing device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device which has excellent development stability even when toner having good fixation within a wide temperature range as toner constituting a two-component developer is used, and can form a toner image capable of providing a high quality visible image for a long time and to provide an image forming apparatus capable of providing a high quality visible image. SOLUTION: The developing device uses the toner obtained by fusion bonding a crystalline material which has specific characteristics and a resin particulate containing an amorphous polymer material in a water system medium as the toner constituting the two-component developer. The developing device is provided with a toner consumption detecting means to detect toner consumption in a developer carrier, a developer agitation feed part and the two-component developer, and a rotation control means to control the rotational speed of a rotating member for mixing and agitating the developer constituting a developer mixing-agitation part according to the toner consumption detected by the toner consumption detecting means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device and an image forming apparatus for developing an electrostatic charge image with a two-component developer.

[0002]

2. Description of the Related Art In a developing device, for example, in an image forming device, a two-component developer (hereinafter referred to simply as "developer") consisting of toner and carrier is formed on the surface of a latent image carrier on which an electrostatic charge image is formed. It is used to form a toner image by developing the electrostatic charge image with toner by bringing the electrostatic charge image into contact.

In a certain type of such a developing device, for example, a developer carrying member composed of a rotary sleeve for supplying the developer to the latent image carrying member by carrying and carrying the developer, A developer mixing and stirring unit that supplies the developer to the developer carrier while mixing and stirring the developer, and a rotating member for mixing and mixing the developer that constitutes the developer mixing and stirring unit (hereinafter, simply When the developing device is replenished with toner (hereinafter, the toner replenished from the toner replenishing mechanism is referred to as “new toner”) by, for example, the toner replenishing mechanism, by constantly rotating the “rotating member”). Also, the toner concentration and toner charge amount of the developer supplied to the latent image carrier are kept within a certain range by the mixing and stirring action of the rotating member.

On the other hand, as the toner constituting the developer,
A toner obtained by fusing fine particles of a resin containing a crystalline substance having specific thermal characteristics and an amorphous polymer substance in an aqueous medium is known. Since such a toner has a wide fixing temperature range and exhibits a good fixing property in a wide temperature range, it has a good image quality even by an image forming method including a low temperature fixing step in response to a request for energy saving. It is advantageous in that a visible image can be formed.

However, since such a toner has a soft surface, for example, a rotating member (hereinafter, also simply referred to as "rotating member") for mixing and stirring the developer in the developer mixing and stirring section, the developer. When the toner is used, it should be formed especially because it is easily deteriorated by the stress caused by the rotation of the components for mixing, stirring and conveying the developer such as the rotating sleeve in the carrier. When the blackening ratio of the visible image is small, fogging is likely to occur, and there is a problem that a visible image having high image quality cannot be obtained. As described above, the deterioration of the toner eventually causes the image quality of the obtained visible image to gradually deteriorate during the visible image forming operation for a long period of time.

When the amount of new toner supplied by the toner replenishing mechanism is small, the need for mixing and agitating the developer is reduced, so that the developing device is constructed so as to control the rotational speed of the rotating member to be small. (See Japanese Patent Laid-Open No. 5-6090), the control of the rotation speed depends only on the amount of new toner supplied from the toner supply mechanism, and the change of the rotation speed triggers the supply of new toner. Therefore, even when the need to mix and stir the developer is reduced due to the reduction in the toner consumption due to the developing operation, it is necessary to wait until the new toner is replenished. The rotation speed of the rotating member is not reduced, and eventually the rotating member performs excessive mixing and stirring operation. Therefore, it is not possible to sufficiently suppress the deterioration due to the mixing, stirring and conveyance of the toner.

[0007]

The present invention has been made based on the above circumstances, and its purpose is to
Even when a toner having a good fixing property in a wide temperature range is used as a toner constituting a component developer, a toner image having excellent development stability and a visible image having high image quality for a long time can be obtained. To provide a developing device capable of forming Another object of the present invention is an image forming apparatus capable of obtaining a high-quality visible image for a long period of time even when a toner having a good fixing property in a wide temperature range is used as a toner constituting a two-component developer. To provide.

[0008]

The developing device of the present invention comprises a crystalline substance having the following characteristics (1) to (3) as a toner constituting a two-component developer comprising a toner and a carrier: Using a toner obtained by fusing resin fine particles containing a fixed polymeric substance in an aqueous medium, a developer carrier comprising a rotary sleeve that carries and conveys the two-component developer, and two-component development In a developing device having a developer agitating and supplying unit that supplies a developer to a developer carrier while mixing and agitating the developer, a toner consumption amount detecting unit for detecting a toner consumption amount in a two-component developer is provided, A rotation control unit that adjusts the rotation speed of the rotating member for developer mixing and stirring that constitutes the developer mixing and stirring unit according to the toner consumption amount detected by the toner consumption amount detecting unit. And it features.

(1) The endothermic peak (P1) in the first temperature rising process measured by a differential calorimeter is 50 to 130 ° C.
Is. (2) The exothermic peak (P2) in the first cooling process measured by a differential calorimeter is 30 to 110 ° C. (3) P1 ≧ P2.

The developing device of the present invention comprises a crystalline substance having the following characteristics (1) to (3) and an amorphous polymer substance as a toner constituting a two-component developer comprising a toner and a carrier. While using the toner obtained by fusing the resin particles contained therein in an aqueous medium, the developer carrying member composed of a rotary sleeve carrying and carrying the two-component developer and the two-component developer are mixed and stirred. In a developing device having a developer stirring and supplying section for supplying to the developer carrying member, toner consumption amount detecting means for detecting the toner consumption amount of the two-component developer is provided, and the toner consumption amount detecting means is provided. It is characterized by having a rotation control means for adjusting the rotational speed of the rotary sleeve which constitutes the developer carrying member according to the toner consumption amount detected by.

(1) The endothermic peak (P1) in the first temperature rising process measured by a differential calorimeter is 50 to 130 ° C.
Is. (2) The exothermic peak (P2) in the first cooling process measured by a differential calorimeter is 30 to 110 ° C. (3) P1 ≧ P2.

In the developing device having the above structure,
It is preferable that the toner consumption amount detecting means detects the toner consumption amount based on the magnetic permeability of the two-component developer.

The developing device of the present invention comprises a crystalline substance having the following characteristics (1) to (3) and an amorphous polymer substance as a toner constituting a two-component developer composed of a toner and a carrier. While using the toner obtained by fusing the resin particles contained therein in an aqueous medium, the developer carrying member composed of a rotary sleeve carrying and carrying the two-component developer and the two-component developer are mixed and stirred. In a developing device having a developer stirring and supplying unit for supplying to the developer carrier, a developer mixing and stirring unit that constitutes a developer mixing and stirring unit according to a predicted toner consumption amount based on image information to be developed. It has a rotation control means for adjusting the rotation speed of the rotating member.

(1) The endothermic peak (P1) in the first temperature rising process measured by a differential calorimeter is 50 to 130 ° C.
Is. (2) The exothermic peak (P2) in the first cooling process measured by a differential calorimeter is 30 to 110 ° C. (3) P1 ≧ P2.

The developing device of the present invention comprises a crystalline substance having the following characteristics (1) to (3) and an amorphous polymer substance as a toner constituting a two-component developer consisting of a toner and a carrier. While using the toner obtained by fusing the resin particles contained therein in an aqueous medium, the developer carrying member composed of a rotary sleeve carrying and carrying the two-component developer and the two-component developer are mixed and stirred. In a developing device having a developer agitating and supplying unit that supplies the developer carrier, the rotation speed of the rotary sleeve that constitutes the developer carrier is adjusted according to the predicted toner consumption based on the image information to be developed. It is characterized by having a rotation control means that adjusts.

(1) The endothermic peak (P1) in the first temperature rising process measured by a differential calorimeter is 50 to 130 ° C.
Is. (2) The exothermic peak (P2) in the first cooling process measured by a differential calorimeter is 30 to 110 ° C. (3) P1 ≧ P2.

In the developing device of the present invention, at least one of the rotating members for mixing and stirring the developer which constitutes the developer mixing and stirring section has a paddle shape.

An image forming apparatus of the present invention is characterized by including the above-mentioned developing device.

Further, the image forming apparatus of the present invention comprises a cleaning section for removing the toner adhering to the surface of the latent image carrier and a recycling means for conveying the toner removed by the cleaning section to the developing apparatus. You may have.

[0020]

According to the developing device of the present invention, the rotational speed of a specific component for mixing, stirring and conveying the two-component developer is adjusted according to the amount of toner required during a series of developing operations. When the necessity of mixing and agitating the two-component developer becomes low, the rotation speed of a specific component becomes small, so that the two-component developer is not adversely affected. It is possible to sufficiently suppress the deterioration due to the mixing, stirring and conveyance of the above. Therefore, even when a toner having a good fixing property in a wide temperature range is used as the toner constituting the two-component developer, excellent development stability can be obtained, and a visible image having a high image quality for a long time can be obtained. Can form a toner image.

[0021]

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

(First Embodiment) FIG. 1 is an explanatory view showing the outline of an example of the constitution of an image forming apparatus of the present invention, and FIG. 2 shows the constitution of a developing device of the image forming apparatus of FIG. FIG. 3 is a transverse plane for explanation shown in FIG. 3, and FIG.
It is a longitudinal plane for explanation showing a cross section A. In this image forming apparatus, a latent image carrier 10 made of, for example, an organic photoconductor, which rotates in a clockwise direction (arrow direction) in FIG. 1, and the latent image carrier 10 are corona discharged by a grid and a corona discharge wire, for example. Charging unit 12 for uniformly charging
And exposing the uniformly charged latent image carrier 10 with laser light emitted from, for example, a laser diode (not shown) based on document image information of an image reading unit (not shown). Image exposing unit 13 that forms an electrostatic charge image on the surface thereof, developing device 20 that develops the electrostatic charge image formed on the surface of latent image carrier 10 to form a toner image, and latent image carrier 10 A transfer section 16 for transferring the toner image formed on the transfer material onto a transfer material such as paper, and a separation section 17 for separating the transfer material in close contact with the latent image carrier 10.
The fixing unit 18 includes a pair of heating rollers 18a and a pair of pressure rollers 18b for fixing the toner image transferred on the surface of the transfer material. In the figure, 11 is a transfer material supplying section, 19 is a cleaning section, and P is a developing area. The cleaning unit 19 includes a cleaning roller 19a that electrically performs cleaning, and a blade 19b that mechanically performs cleaning.

As shown in FIGS. 2 and 3, the developing device 20 has an opening 28C on the side surface facing the latent image carrier 10.
Housing 2 in which a developer (two-component developer) composed of toner and carrier having specific characteristics described below is introduced
8, a plurality of fixed magnets (not shown) are provided inside, and a developer carrying member 21 including a rotating sleeve 22 carrying a developer and supplying it to the latent image carrying member 10, and the developer carrying member 21. A developer regulating member 23 that regulates the thickness of the developer layer formed on the surface of the body 21, and a developer mixing and stirring unit 24 for mixing and stirring the developer and supplying the developer to the developer carrying body 21. It has and. In this example, the developer mixing and stirring section 24 on the top plate 28A of the housing 28 is used.
27A of the mixing screw 27 described later in FIG.
A toner replenishment opening (not shown) for supplying new toner into the housing 28 is formed at the upper position (the position indicated by (a) in FIG. 2).

The developer mixing and stirring section 24 is composed of a cross paddle-shaped rotating member (rotating member for mixing and mixing the developer) which rotates counterclockwise (arrow direction) in FIG. 3, and while stirring the developer. A spiral having a developer stirring and supplying member (hereinafter, also referred to as “stirring and supplying paddle”) 25 to be supplied to the developer carrying member 21 and a plate-shaped blade member 26A at one end side (upper end side in FIG. 2). The first developer mixing member (1) that mixes the new toner replenished through the toner replenishment opening of the housing 28 with the developer in the housing 28 by the toner replenishment mechanism (not shown). Hereinafter, also referred to as "first mixing screw".) 26
And the plate-shaped blade member 2 on the other end side (the lower end side in FIG. 2)
The housing 2 is composed of a spiral rotating member having 7A.
A second developer mixing member (hereinafter, also referred to as “second mixing screw”) 27 arranged in parallel to the first mixing screw 26 with a partition wall 29 projecting from the bottom plate 28B of No. 8 interposed therebetween. , Agitating and feeding paddle 2 by driving
5, a rotation drive mechanism (not shown) for rotating the first mixing screw 26 and the second mixing screw 27, respectively.
It is composed of and.

In this example, the new toner replenished from the toner replenishment opening first passes through the first communication opening 29C of the partition wall 29 in the clockwise direction (arrow direction) in FIG.
3 through the developer conveying path (hereinafter, also referred to as “first conveying path”) 29A related to the first mixing screw 26 that rotates in the direction of FIG. 3 and then through the second communication opening 29D of the partition wall 29. In the developer carrying path (hereinafter, referred to as the second mixing screw 27 rotating in the counterclockwise direction (arrow direction)).
Also referred to as the "second transport path". ) 29B is mixed in the process of being conveyed. A developer carrying path is formed here by the first carrying path 29A and the second carrying path 29B.

In the developing device 20, for example, the inside of the housing 28 is located at a position adjacent to the toner supply opening of the second conveying path 29B in the developer mixing / stirring section 24 (the position indicated by the arrow (B) in FIG. 2). A toner concentration detecting means (not shown) for detecting the toner concentration is provided.
Based on the toner concentration information detected by the toner concentration detecting means, a replenishment command signal and a replenishment stop signal are transmitted from a control unit (not shown) to the toner replenishment mechanism, for example.

Then, in the developer mixing / stirring section 24 composed of the stirring / supplying paddle 25, the first mixing screw 26 and the second mixing screw 27, the most upstream position of the developer transport path (in FIG. 3). At a position indicated by an arrow (c)), a toner consumption amount detecting unit (not shown) including a magnetic permeability detecting sensor is provided.

The toner consumption amount detecting means utilizes the fact that the toner concentration in the developer and the magnetic permeability are in inverse proportion to each other, and uses the information on the change rate of the magnetic permeability measured by the magnetic permeability detecting sensor per unit time. The toner consumption amount is calculated based on Actually, based on the information on the change rate of the magnetic permeability per unit time measured by the magnetic permeability detection sensor, the information on the change rate of the toner concentration in the developer per unit time is obtained. The toner consumption amount is calculated based on the change rate information.

Further, there is provided rotation control means (not shown) for adjusting the rotation speed of the stirring and supplying paddle 25 by the rotation drive mechanism according to the toner consumption amount detected by the toner consumption amount detecting means. The rotation control means controls the rotation speed of the stirring and supplying paddle 25 by the rotation drive mechanism to become lower than the reference rotation speed when the toner consumption amount becomes equal to or lower than a certain level. In one specific example,
The time required to form a visible image on the surface of at least one transfer material, specifically, 4 seconds from the start of a series of visible image forming operations in the image forming apparatus (hereinafter, also referred to as "operation initial period"). Toner consumption in the
When it becomes below, the rotation speed of the agitation and supply paddle 25 is set to 70% of the number of rotations per unit time of the reference rotation speed, and when the toner consumption amount becomes 2 mg or less, the agitation and supply paddle 25. The rotation speed of 25 is controlled to be 50% of the rotation speed per unit time of the reference rotation speed.

As the rotation control means, for example, a means for changing a voltage value supplied to a motor constituting a rotation drive mechanism by a signal from a CPU (central processing unit) is used.

The operation of the image forming apparatus as described above is as follows. The image of the document is read by the image reading unit to obtain the document image information, and the image exposure unit 13 performs exposure based on the document image information.
An electrostatic charge image is formed on the surface of the latent image carrier 10. on the other hand,
The transfer material is delivered from the transfer material supply unit 11 and is conveyed toward the transfer unit 16 in synchronization with the latent image carrier 10.

In the developing device 20, the toner and the carrier are mixed in the housing 28 by the mixing screw 2.
6, 27, and is supplied to the surface of the developer carrier 21 while being agitated by the agitation and supply paddle 25 and attached to the surface of the developer carrier 21 to form a developer layer. Is transported to the developing area P after the thickness thereof is regulated by the developer regulating member 23 to a required amount of the developer, and in this developing area P, the developer layer is formed on the surface of the latent image carrier 10. A magnetic brush is formed and contacted, whereby toner adheres and develops according to the electrostatic charge image formed on the surface of the latent image carrier 10 to obtain a toner image.

The toner image thus formed on the surface of the latent image carrier 10 is transferred to the transferred transfer material in the transfer section 16. Then, the transfer material which is in close contact with the latent image carrier 10 is separated from the latent image carrier 10 in the separation unit 17 immediately after the transfer of the toner image. afterwards,
The transfer material separated from the latent image carrier 10 is conveyed toward the fixing section 18, and the toner image is thermally fixed in the fixing section 18, and a visible image corresponding to the image of the original is formed on the transfer material. The transfer material on which the visible image is formed is ejected from the fixing section 18, then conveyed and ejected to the outside.
Further, the latent image carrier 10 after the transfer material is separated passes through the cleaning unit 19, so that the toner remaining on the surface is removed.

During the visible image forming operation of the image forming apparatus as described above, for example, the toner in the housing 28 detected by the toner concentration detecting means provided upstream of the toner replenishment opening of the developer mixing and stirring section 24. When the concentration is too low, the control unit issues a replenishment command signal,
Upon receipt of this replenishment command signal, new toner is replenished from the toner replenishment mechanism to the developing device 20, and on the other hand, when the toner concentration in the housing 28 becomes excessive due to the replenishment of new toner from the toner replenishment mechanism, the control unit A replenishment stop signal is issued, and replenishment of new toner by the toner replenishment mechanism is stopped. In this way, new toner is replenished to the developing device 20 from the toner replenishing mechanism.

In the developing device 20, the stirring and supplying paddle 25 and the mixing screws 26 and 27 are always rotated by the rotation driving mechanism during a series of visible image forming operations. When the toner consumption detected by the means falls below a certain level,
The rotation control means reduces the rotation speed of the stirring supply paddle 25 by the rotation drive mechanism.

As described above, when the necessity of mixing and agitating the developer becomes low, the rotational speed of the agitating and supplying paddle 25 is reduced to make the toner of the developer as a toner constituting the developer of the developer in a developing device described later. It is prone to deterioration due to stress associated with mixing, stirring, and transportation, but even when a toner exhibiting good fixing properties in a wide temperature range is used, deterioration of toner due to mixing, stirring, and transportation of developer is sufficiently performed. Can be suppressed. Then, by decreasing the rotation speed of the stirring and supplying paddle 25, the amount of toner supplied to the developer carrying member 21 per unit time is reduced, but the amount of toner required for a visible image to be formed is reduced. Since there is little, there is no adverse effect such as unevenness in the obtained visible image. Therefore,
The image forming apparatus including the developing device 20 can obtain a high-quality visible image for a long period of time even when a toner having a good fixing property in a wide temperature range is used as the toner forming the developer. .

In the first embodiment as described above,
Various changes can be made. For example, the toner consumption amount detecting means can be provided at any position in the housing.

Further, the toner concentration detecting means may be so constructed as to detect the toner concentration in the housing based on the magnetic permeability of the developer measured by the magnetic permeability detecting sensor constituting the toner consumption detecting means. .

The developer suitable for use in the image forming apparatus having the above-mentioned structure is produced by fusing resin fine particles containing a crystalline substance and an amorphous polymer substance in an aqueous medium. Examples of the toner include a toner and a carrier.

The water-based medium used for fusing the resin fine particles is one whose main component (50% by mass or more) is water, and as the components other than water, for example, methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, An organic solvent that dissolves in water, such as tetrahydrofuran, may be mentioned. Among these organic solvents, alcohol-based organic solvents such as methanol, ethanol, isopropanol and butanol, which are resin-insoluble organic solvents, are particularly preferable.

As a method for fusing resin fine particles in an aqueous medium, for example, JP-A-63-186253, JP-A-63-282749, and JP-A-7-146583.
The method described in Japanese Patent Publication can be used. A particularly preferable method is a method of salting out / fusing resin fine particles in an aqueous medium. Here, "salting out / fusion" means that salting out (aggregation of fine particles) and fusion (disappearance of the interface between the fine particles) occur at the same time, or the action of causing salting out and fusion at the same time. Say. In order to carry out salting out and fusion at the same time, it is necessary to aggregate the fine particles under a temperature condition equal to or higher than the glass transition temperature (Tg) of the resin constituting the fine resin particles.

The weight average particle diameter of the resin fine particles is 50 to 200.
It is preferably 0 nm. The resin fine particles may be obtained by any of granulation polymerization methods such as emulsion polymerization method, suspension polymerization method and seed polymerization method, but those obtained by emulsion polymerization method are preferable.

As the crystalline substance contained in the resin fine particles constituting the toner, a differential calorimeter (hereinafter referred to as "DS") is used.
Also referred to as "C". ) Has an endothermic peak (P1) in the first temperature rising process of 50 to 130 ° C., preferably 60 to 1
It is at 20 ° C. Further, the crystalline substance has an exothermic peak (P2) of 30 to 110 in the first cooling process by DSC.
C., preferably 40 to 120.degree. here,
The endothermic peak (P1) and the exothermic peak (P2) are P1
The relation of ≧ P2 is established. The temperature difference (P1-P2) is not particularly limited, but is preferably 50 ° C or less.

By containing the crystalline substance having the above-mentioned thermal characteristics as a resin component of the toner, an excellent offset prevention effect (wide fixing temperature range) and an excellent fixing property (high fixing ratio) are exhibited. Can be made.
In order to exert this effect, it is preferable that the amorphous polymer substance and the crystalline substance exist independently of each other. That is, the crystalline substance dissolves sharply,
In the molten state, it acts to dissolve the amorphous polymer substance, and as a result, the melt viscosity of the entire toner can be lowered and the fixing property can be improved. Further, since they exist independently of each other, it is possible to suppress the decrease in elastic modulus on the high temperature side, and therefore the offset resistance is not impaired.

When the endothermic peak (P1) is below 50 ° C., the melting temperature is low, so that the fixing property is improved but the offset resistance and the storage stability are deteriorated.
Further, when the endothermic peak (P1) is in the range of more than 130 ° C., the melting temperature is high, so that the melting temperature with the amorphous polymer substance becomes high, and as a result, the fixing property can be improved. Can not.

Exothermic peak (P2) showing the state of recrystallization
Is less than 30 ° C., it cannot be recrystallized unless it is cooled to a considerably low temperature, and such a substance exists in the toner in a state of low crystallinity, and the fixability is low. Can not contribute to the improvement of. Further, when the exothermic peak (P2) exists in the range of more than 110 ° C., the recrystallization temperature is too high and the so-called melting temperature becomes high, so that the low temperature fixability is impaired.

Here, the measurement by DSC is 1 at 0 ° C.
After standing for 10 minutes, the temperature is raised to 200 ° C. under the condition of 10 ° C./min, the temperature showing the maximum endothermic peak measured at that time is set to P1, and then, after standing at 200 ° C. for 1 minute, 1
The temperature is lowered under the condition of 0 ° C./min, and the heating / cooling conditions are set such that the temperature showing the maximum exothermic peak measured at that time is P2. As a specific measuring device, Perkin Elmer's DSC-7 and the like can be mentioned.

The number average molecular weight of the crystalline substance is from 1,500 to
It is preferably 15,000, and more preferably 2,000 to 10,000. 1,500-1
The crystalline substance having a number average molecular weight in the range of 5,000 improves the compatibility of the obtained toner with the amorphous polymer substance in the molten state in order to exert a decrease in the overall melt viscosity. , The fixability on the lower temperature side is improved. When the number average molecular weight is less than 1,500, the melt viscosity of the crystalline substance becomes excessively low, and the compatible state tends to be nonuniform, and the fixability cannot be improved. On the other hand, when the number average molecular weight exceeds 15,000, it takes a long time to melt the crystalline substance, and even in this case, the compatibility state becomes nonuniform, so that the effect of improving the fixing property becomes low.

Examples of the compound constituting the crystalline substance include polyester, polyamide and polyimide, which are obtained by reacting an aliphatic diol with an aliphatic dicarboxylic acid (including an acid anhydride and an acid chloride). Aliphatic polyamides obtained by reacting the aliphatic polyesters and aliphatic diamines with aliphatic dicarboxylic acids (including acid anhydrides and acid chlorides) are preferable, and aliphatic polyesters are particularly preferable. Here, the dicarboxylic acid and diol used for preparing the crystalline substance are preferably those without a branched chain (having a skeleton having 1 or more carbon atoms such as an alkyl group from the skeleton of the main chain).

The diols used to obtain the crystalline polyester include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,
4-butanediol, 1,4, butenediol, neopentyl glycol, 1,5-pentanediol, 1,6
-Hexanediol, decanediol, hexadecanediol, dodecanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like can be mentioned.

As the diamine used to obtain the crystalline polyamide, ethylenediamine, diethylenediamine, triethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,4-butanediamine, 1,4- Butenediamine, 2,2-dimethyl-
1,3-butanediamine, 1,5-pentanediamine,
1,6-hexanediamine, 1,4-cyclohexanediamine, 1,4-cyclohexanedimethylamine and the like can be mentioned.

Dicarboxylic acids used to obtain crystalline polyesters and crystalline polyamides include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid,
Pimelic acid, speric acid, azelaic acid, sebacic acid,
Maleic acid, fumaric acid, citraconic acid, itaconic acid, glutacoic acid, n-dodecylsuccinic acid, n-dodecenylsuccinic acid, isododecylsuccinic acid, isododecenylsuccinic acid, n-octylsuccinic acid, n-octenylsuccinic acid,
These acid anhydrides or acid chlorides can be mentioned.

In addition to the condensation of the above aliphatic dicarboxylic acid and the aliphatic diol, the aliphatic polyester may be prepared by ring-opening polymerization of various lactones. In this case, as the lactone, δ-valerolactone,
Examples include ε-caprolactone and β-propiolactone. As a particularly preferred crystalline substance,
Polyester obtained by reacting cyclohexanediol and adipic acid, polyester obtained by reacting 1,6 hexanediol and sebacic acid, polyester obtained by reacting ethylene glycol and succinic acid, ethylene glycol and sebacic acid And polyesters obtained by reacting 1,4-butanediol and succinic acid. Among these, polyesters obtained by reacting cyclohexanediol and adipic acid are Most preferred.

The amorphous polymer substance contained in the resin fine particles constituting the toner is preferably an amorphous vinyl polymer and satisfies the following conditions (1) to (4).

(1) Glass transition temperature (Tg) is 10 to 7
It is preferably in the range of 5 ° C, more preferably 40
~ 65 ° C. (2) The softening point is preferably in the range of 80 to 220 ° C. (3) The weight average molecular weight (Mw) is 5,000.
The number average molecular weight (Mn) is preferably 2,000 to 200,000, more preferably 8,000 to 500,000. (4) The molecular weight distribution (Mw / Mn) is preferably 2.0 to 100, more preferably 5.0 to 80.

A colorant can be used in the toner, and examples of this colorant include inorganic pigments and organic pigments. As the inorganic pigment, conventionally known ones can be used. Specific inorganic pigments are exemplified below. Examples of black pigments include carbon black such as furnace black, channel black, acetylene black, thermal black, and lamp black.
Further, magnetic powders such as magnetite and ferrite are also used. These inorganic pigments can be used alone or in combination of two or more as desired. The amount of the pigment added is 2 to 20% by mass with respect to the polymer, and preferably 3 to 15%.
Mass% is selected. When used as a magnetic toner, the above magnetite can be added. In this case, from the viewpoint of imparting predetermined magnetic properties, it is preferable to add 20 to 60% by weight to the toner.

As the organic pigment, conventionally known ones can be used. Specific organic pigments are exemplified below. Pigments for magenta or red include C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I.
Pigment Red 5, C.I. I. Pigment Red 6,
C. I. Pigment Red 7, C.I. I. Pigment Red 15, C.I. I. Pigment Red 16, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 5
3: 1, C.I. I. Pigment Red 57: 1, C.I. I.
Pigment Red 122, C.I. I. Pigment Red 1
23, C.I. I. Pigment Red 139, C.I. I. Pigment Red 144, C.I. I. Pigment Red 14
9, C.I. I. Pigment Red 166, C.I. I. Pigment Red 177, C.I. I. Pigment Red 178,
C. I. Pigment Red 222 and the like. Pigments for orange or yellow include C.I. I. Pigment Orange 31, C.I. I. Pigment Orange 4
3, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14,
C. I. Pigment Yellow 15, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 93, C.I.
I. Pigment Yellow 94, C.I. I. Pigment Yellow 138 and the like. Pigments for green or cyan include C.I. I. Pigment Blue 15, C.I.
I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Blue 16, C.I.
I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like. These organic pigments can be used alone or in combination of two or more as desired. The amount of the pigment added is 2 to 20% by mass with respect to the polymer,
Preferably 3 to 15 mass% is selected.

The colorant may be used after surface modification. As the surface modifier, a conventionally known one can be used, and specifically, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent and the like can be preferably used.

A so-called external additive may be added to the toner for the purpose of improving fluidity, charging property and cleaning property. These external additives are not particularly limited, and various inorganic fine particles, organic fine particles and lubricants can be used. As the inorganic fine particles, conventionally known ones can be used. Specifically, silica, titanium, alumina fine particles and the like can be preferably used. The inorganic fine particles are preferably hydrophobic. Specifically, as the silica fine particles, for example, commercially available products R-805 and R manufactured by Nippon Aerosil Co., Ltd.
-976, R-974, R-972, R-812, R-
809, Hovst HVK-2150, H-20
0, Cabot's commercial products TS-720, TS-53
0, TS-610, H-5, MS-5 and the like. Examples of the titanium fine particles include commercial products T-805 and T-604 manufactured by Nippon Aerosil Co., Ltd., and commercial products MT-100S, MT-100B and MT-500B manufactured by Teika.
S, MT-600, MT-600SS, JA-1, commercial products TA-300SI, TA-500 manufactured by Fuji Titanium Co., Ltd.
TAF-130, TAF-510, TAF-510T,
Commercial products IT-S, IT-OA, IT-O manufactured by Idemitsu Kosan Co., Ltd.
B, IT-OC and the like. As the alumina fine particles, for example, commercially available product RFY- manufactured by Nippon Aerosil Co., Ltd.
C, C-604, a commercial product TTO-55 manufactured by Ishihara Sangyo Co., Ltd. and the like can be mentioned. As the organic fine particles, spherical organic fine particles having a number average primary particle diameter of about 10 to 2000 nm can be used. As this, a homopolymer such as styrene or methyl methacrylate or a copolymer thereof can be used. Lubricants include, for example, zinc stearate, aluminum, copper, magnesium, calcium salts, etc., zinc oleate, manganese, iron,
Salts of copper, magnesium, zinc palmitate, copper,
Metal salts of higher fatty acids such as salts of magnesium and calcium, zinc of linoleic acid, salts of calcium and the like, salts of zinc of ricinoleic acid, calcium and the like can be mentioned.
The addition amount of these external additives is preferably 0.1 to 5 mass% with respect to the toner.

The average particle diameter of the toner is preferably 4 to 8 μm.

As the carrier, magnetic particles made of conventionally known materials such as metals such as iron, ferrite and magnetite, and alloys of these metals with metals such as aluminum and lead can be used. In particular, ferrite particles can be used. Is preferred. The volume average particle size of the carrier is 15
˜100 μm, more preferably 2
It is set to 5 to 60 μm.

Preferred carriers include resin-coated carriers in which the surface of magnetic particles is coated with a resin, and so-called resin dispersion type carriers in which magnetic particles are dispersed in a resin. The resin constituting the resin-coated carrier is not particularly limited, but for example, an olefin resin, a styrene resin, a styrene / acrylic resin,
Examples thereof include silicone resins, ester resins, fluorine-containing polymer resins and the like. The resin constituting the resin-dispersed carrier is not particularly limited, and known ones can be used, and for example, styrene acrylic resin, polyester resin, fluorine resin, phenol resin and the like can be used.

The developer is prepared by mixing the above toner and carrier. When mixing the toner and the carrier, a conventionally known mixer can be used, but a mixer that exerts less stress on the toner and the carrier when mixing, for example, a high-speed stirring type mixer such as a hen shell mixer. Than V type mixer, W cone mixer,
It is preferable to use a rotation type mixer such as a rocking mixer. Further, the mixing ratio of the toner and the carrier is such that the mixing ratio of the toner is 2. with respect to the total mass of the developer.
It is preferably in the range of 0 to 10.0 mass%.

(Second Embodiment) In the image forming apparatus of the second embodiment, instead of the toner consumption amount detecting means, image information of a visible image to be formed, specifically, an image reading unit. The estimated toner consumption amount calculating means for calculating the estimated toner consumption amount based on the document image information obtained by the operation, for example, the image density information input via the operation panel is provided, and the estimated toner consumption amount is calculated by the estimated toner consumption amount calculation means. The configuration is similar to that of the first embodiment, except that a rotation control unit that controls the rotation speed of the developer agitation supply member by the rotation drive mechanism is provided according to the estimated toner consumption amount.

As the toner estimated consumption amount calculating means, for example, the toner estimated consumption amount is calculated on the basis of the image information including the image information obtained by the image reading unit and the image density information input through the operation panel. An arithmetic circuit can be used.

Then, when the estimated toner consumption amount by the estimated toner consumption amount detecting means is below a certain level, the rotation control means causes the rotation speed of the developer agitation supply member by the rotation drive mechanism to be smaller than the reference rotation speed. Control to be. In a specific example, when the expected toner consumption amount is 5 mg or less, the rotation speed of the developer stirring and supplying member is 70 times the rotation speed per unit time of the reference rotation speed.
%, And when the predicted toner consumption amount is 3 mg or less, the rotation speed of the developer stirring and supplying member is controlled to be 50% of the rotation speed per unit time of the reference rotation speed.

According to the image forming apparatus having such a configuration,
For example, when a small amount of toner is consumed in the developing device 20 during a series of image forming operations, for example, a visible image in which an amount of toner of 5 mg or less is required for a transfer material of A4 size is continuously formed. In the case of the formation, the estimated toner consumption amount calculated by the estimated toner consumption amount calculation unit based on the image information such as the document image information and the density information becomes small, and accordingly the developer agitation supply by the rotation drive mechanism is performed. Since the rotation speed of the member is reduced by the rotation control means, it is possible to suppress the deterioration of the toner without causing an adverse effect such as unevenness in the obtained visible image. Therefore, even when a toner having a good fixing property in a wide temperature range is used as the toner constituting the developer, a visible image with high image quality can be obtained for a long period of time.

The image forming apparatus of the present invention as described above has a good fixing property as a toner constituting a developer in a wide temperature range, and is subjected to stress due to mixing, stirring and carrying of the developer in the developing apparatus. A developing device capable of forming a toner image capable of obtaining a visible image having a high image quality for a long period of time even when a toner that is easily deteriorated is used and excellent developing stability can be obtained. Therefore, a high-quality visible image can be obtained over a long period of time.

Various modifications can be made in the present invention. For example, the image forming apparatus includes a recycling unit that conveys the toner (recycled toner) removed by the cleaning unit to the developing device, and a part or all of the recycled toner removed by the cleaning unit by the recycling unit. May be transported to the developing device and reused.

In such a case, during the series of visible image forming operations, the recycled toner is fed to the developing device through the toner replenishing opening in the housing, for example, new toner is replenished, and is supplied. Since the rotation speed of the specific constituent member is controlled by the rotation control means according to the amount of toner required during a series of developing operations, the deterioration of the toner is suppressed and the amount of the developer in the developing device is reduced. The toner concentration and the toner charge amount can be kept within a certain range.

Further, as the developing device, for example, instead of the rotation control means for controlling the rotation speed of the rotating member (rotating member for developer mixing and stirring) constituting the developer mixing and stirring section according to the first embodiment. A rotation control unit that adjusts the rotation speed of the rotary sleeve that constitutes the developer carrier according to the toner consumption amount by the toner consumption amount detection unit may be provided. The rotation control unit controls the rotation speed of the rotating sleeve to be lower than the reference rotation speed when the toner consumption amount is below a certain level.
In a specific example, for example, when the toner consumption amount is 5 mg or less, the rotation speed of the rotating sleeve is 70% of the rotation number per unit time of the reference rotation speed, and the toner consumption amount is 3 mg or less. In such a case, the rotation speed of the rotary sleeve is controlled to be 50% of the rotation speed per unit time of the reference rotation speed.

In this case, the amount of toner supplied to the latent image carrier per unit time is small, but since the amount of toner required for a visible image to be formed is small, for example, the obtained visible image is obtained. It is possible to suppress deterioration of the toner without causing an adverse effect such as image unevenness.

In the developing device, the rotation speed of the developer mixing member of the developer mixing and stirring section may be controlled, or the rotation speeds of a plurality of constituent members may be controlled. Good. Further, the rotation control means may perform appropriate control based on each of the plurality of control factors.

[0074]

EXAMPLES Examples of the present invention will be described below.
The present invention is not limited to these.

<Embodiment 1> According to the structure shown in FIG. 1, a first member having a developer carrying member and a developer mixing and stirring section.
An image forming apparatus including the developing device according to the embodiment is manufactured.

A resin cross paddle having a diameter of 20 mm is used as a developer stirring and supplying member in the developer mixing and stirring section, and a spiral rotating member made of aluminum having a blade member on one end side and having a diameter of 18 mm is used as the developer mixing member. A member was used.

As the rotation control means for the developer stirring / supplying member, the reference rotation speed of the developer stirring / supplying member is set to 288 rpm, and the toner consumption detecting means including a magnetic permeability detecting sensor (manufactured by TDK Corporation) is used. When the amount of toner consumption detected during the four seconds from the start of the visible image forming operation of the image forming apparatus is 10 mg or less, the rotational speed is controlled to 202 rpm.

As the developer, a crystalline polyester (crystalline substance) obtained from succinic acid and ethylene glycol having the following characteristics (1) to (3) and styrene /
A toner produced by fusing fine particles made of a resin containing an n-butyl acrylate / methacrylic acid copolymer (amorphous polymer substance) in an aqueous medium, and a volume average particle diameter coated with a silicone resin. A carrier composed of a ferrite carrier of 60 μm was used. Also,
In this developer, carbon black (“Regal 330R” manufactured by Cabot Corporation) was used as the colorant,
As the external additive, hydrophobic silica (hydrophobicity 65, number average particle size 12 nm) was used.

(1) The endothermic peak (P1) in the first temperature rising process measured by a differential calorimeter is 95 ° C. (2) The exothermic peak (P2) in the first cooling process measured by a differential calorimeter is 75 ° C. (3) P1 ≧ P2.

By moving the image forming apparatus having the above structure,
A visible image with a blackened area ratio of 1.8% was continuously formed 2000 times on A4 paper as a transfer material, and the state of fogging in the visible image obtained during the visible image forming operation was visually observed. I confirmed it. The results are shown in Table 1. Regarding the state of fogging, a good state without fogging was evaluated as “A”, and there was a slight fogging, but when there was no problem in practical use, it was evaluated as “B”. When coming, it evaluated as "C".

Comparative Example 1 An image forming apparatus having the same structure as in Example 1 was used, and the rotation speed of the developer stirring / supplying member during the visible image forming operation was controlled without controlling the rotation speed of the developer stirring / supplying member. By the same method as in Example 1 except that the speed was always 288 rpm, the occurrence state of fogging of the obtained visible image was confirmed. The results are shown in Table 1.

[0082]

[Table 1]

From the above results, according to the image forming apparatus of the first embodiment, even when a toner having a good fixing property in a wide temperature range is used as the toner forming the developer, It was confirmed that a high quality visible image can be obtained.

<Embodiment 2> As a developing device, the reference rotation speed of the developer agitation supply member is set to 288 rpm, and when the estimated toner consumption amount calculated by the estimated toner consumption amount calculation means is 2 mg or less, the rotation speed thereof is set. 144 rpm
An image forming apparatus having the same configuration as that of the first embodiment is used except that a rotation control unit for performing the control is used, and a method similar to that of the first embodiment except that the image forming apparatus is used. Thus, the occurrence state of fogging of the obtained visible image was confirmed. The results are shown in Table 2.

Comparative Example 1 An image forming apparatus having the same structure as in Example 2 was used, and the rotation speed of the developer stirring and supplying member was not controlled and the rotation speed of the developing stirring and supplying member was kept constant during the visible image forming operation. Example 2 except that 288 rpm was used.
By the same method as described above, the occurrence state of fogging of the obtained visible image was confirmed. The results are shown in Table 2.

[0086]

[Table 2]

From the above results, according to the image forming apparatus according to the second embodiment, even when a toner having a good fixing property in a wide temperature range is used as the toner constituting the developer, It was confirmed that a high quality visible image can be obtained.

[0088]

According to the developing device of the present invention, the rotational speed of a specific component for mixing, stirring and conveying a two-component developer according to the amount of toner required during a series of developing operations. A rotation control means for adjusting the amount of the two-component developer is provided, and when the need for mixing and stirring the two-component developer becomes low,
Since the rotation speed of the specific constituent member becomes small, deterioration due to mixing, stirring, and conveyance of the two-component developer can be sufficiently suppressed without any adverse effect. Therefore, 2
Even when a toner having a good fixing property in a wide temperature range is used as a toner constituting the component developer, excellent development stability can be obtained, and a visible image having high image quality can be obtained for a long time. A toner image can be formed.

According to the image forming apparatus of the present invention, even when a toner having a good fixing property in a wide temperature range is used as a toner constituting a developer, it has excellent development stability and a good toner. Since the developing device of the present invention capable of forming an image is provided, a visible image of high image quality can be obtained for a long period of time.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an outline of an example of a configuration of an image forming apparatus of the present invention.

FIG. 2 is a cross-sectional plan view for explaining a configuration of a developing device of the image forming apparatus of FIG.

3 is a vertical plan view for explaining an AA cross section of the developing device according to FIG.

[Explanation of symbols]

10 latent image carrier 11 transfer material supply unit 12 charging unit 13 image exposure unit 16 transfer unit 17 separation unit 18 fixing unit 18a heating roller 18b pressure roller 19 cleaning unit 19a cleaning roller 19b blade 20 developing device 21 developer carrier 22 Rotating sleeve 23 Developer regulating member 24 Developer mixing and stirring section 25 Developer stirring and supplying member (stirring and supplying paddle) 26 First developer mixing member (first mixing screw) 26A Blade member 27 Second developer mixing member (Second mixing screw) 27A Blade member 28 Housing 28A Top plate 28B Bottom plate 28C Opening 29 Partition 29A First developer transport path 29B Second developer transport path 29C First communication opening 29D Second communication opening P development area

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/08 507X 9/08 321 381 325 331 (72) Inventor Yotaro Sato 2970 Ishikawacho, Hachioji, Tokyo Konica stock company (72) Inventor Hiroshi Akita 2970 Ishikawa-cho, Hachioji, Tokyo Konica stock company F-term (reference) 2H005 AA01 AB03 CA03 CA08 CA09 EA03 FA02 2H077 AB02 AB03 BA02 BA03 DA10 DA15 DA42 DA52 DB25 EA03

Claims (8)

[Claims] 1. As a toner constituting a two-component developer comprising a toner and a carrier, resin fine particles containing a crystalline substance having the following characteristics (1) to (3) and an amorphous polymer substance: A toner obtained by fusing in an aqueous medium is used, and a developer carrying member composed of a rotary sleeve that carries and conveys the two-component developer and the developer carrying member while mixing and stirring the two-component developer. In a developing device having a developer agitating and supplying section for supplying the toner to the toner, a toner consumption detecting means for detecting the toner consumption of the two-component developer is provided, and the toner detected by the toner consumption detecting means. A developing device comprising: a rotation control unit that adjusts a rotation speed of a rotating member for mixing and stirring a developer that constitutes a developer mixing and stirring unit according to a consumption amount. (1) The endothermic peak (P1) in the first temperature rising process measured by a differential calorimeter is 50 to 130 ° C. (2) The exothermic peak (P2) in the first cooling process measured by a differential calorimeter is 30 to 110 ° C. (3) P1 ≧ P2. 2. A resin fine particle containing a crystalline substance having the following characteristics (1) to (3) and an amorphous polymer substance as a toner constituting a two-component developer comprising a toner and a carrier. A toner obtained by fusing in an aqueous medium is used, and a developer carrying member composed of a rotary sleeve that carries and conveys the two-component developer and the developer carrying member while mixing and stirring the two-component developer. In a developing device having a developer agitating and supplying section for supplying the toner to the toner, a toner consumption detecting means for detecting the toner consumption of the two-component developer is provided, and the toner detected by the toner consumption detecting means. A developing device comprising: a rotation control unit that adjusts a rotation speed of a rotating sleeve that constitutes a developer carrier according to a consumption amount. (1) The endothermic peak (P1) in the first temperature rising process measured by a differential calorimeter is 50 to 130 ° C. (2) The exothermic peak (P2) in the first cooling process measured by a differential calorimeter is 30 to 110 ° C. (3) P1 ≧ P2. 3. The developing device according to claim 1, wherein the toner consumption amount detecting means detects the toner consumption amount based on the magnetic permeability of the two-component developer. 4. A resin fine particle containing a crystalline substance having the following characteristics (1) to (3) and an amorphous polymer substance as a toner constituting a two-component developer comprising a toner and a carrier. A toner obtained by fusing in an aqueous medium is used, and a developer carrying member composed of a rotary sleeve that carries and conveys the two-component developer and the developer carrying member while mixing and stirring the two-component developer. In a developing device having a developer agitating and supplying section that supplies toner to the developer, the rotation of the rotating member for agitating and mixing the developer that constitutes the developer mixing and agitating section is performed according to the estimated toner consumption based on the image information to be developed. A developing device having a rotation control means for adjusting the speed. (1) The endothermic peak (P1) in the first temperature rising process measured by a differential calorimeter is 50 to 130 ° C. (2) The exothermic peak (P2) in the first cooling process measured by a differential calorimeter is 30 to 110 ° C. (3) P1 ≧ P2. 5. A resin fine particle containing a crystalline substance having the following characteristics (1) to (3) and an amorphous polymer substance as a toner constituting a two-component developer consisting of a toner and a carrier. A toner obtained by fusing in an aqueous medium is used, and a developer carrying member composed of a rotary sleeve that carries and conveys the two-component developer and the developer carrying member while mixing and stirring the two-component developer. In a developing device having a developer agitating and supplying section that supplies toner to the developer, a rotation control unit that adjusts the rotation speed of a rotating sleeve that constitutes the developer carrier according to the predicted toner consumption based on the image information to be developed. And a developing device. (1) The endothermic peak (P1) in the first temperature rising process measured by a differential calorimeter is 50 to 130 ° C. (2) The exothermic peak (P2) in the first cooling process measured by a differential calorimeter is 30 to 110 ° C. (3) P1 ≧ P2. 6. The developer mixing / stirring section, wherein at least one of the rotating members for mixing / stirring the developer has a paddle shape. Developing device. 7. An image forming apparatus comprising the developing device according to any one of claims 1 to 6. 8. A cleaning unit for removing the toner adhering to the surface of the latent image carrier, and a recycling unit for transporting the toner removed by the cleaning unit to a developing device. 7. The image forming apparatus according to item 7.