JP2008152204A - Toner, image forming method and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the occurrence of a ghost even in a large-capacity and high-speed development process, to prevent the occurrence of image density rising and falling phenomenon, effectively suppressing the occurrence of a problem such as paper contamination due to toner scattering, and for a long time. Providing a toner capable of obtaining a stable and high-quality image.
A toner used in an image forming method having a circulation step of circulating by a toner circulation guide member,
The toner has toner particles containing at least a binder resin and a colorant, and inorganic fine particles, and has the following relational expressions (1) and (2):
600 (mJ) ≦ E ≦ 1500 (mJ) (1)
500 (mJ) ≦ (E−Ea) (2)
[Selection figure] None

Description

  The present invention relates to toner used in an electrophotographic image forming method for developing an electrostatic charge image, toner used in a toner jet, an image forming method, and a process cartridge.

  As a general electrophotographic image forming method, for example, the following methods are known. First, an electrostatic latent image is formed on the electrostatic latent image carrier by various means, and the electrostatic latent image is visualized by developing it with toner into a toner image. Next, the toner image is transferred to a transfer material such as paper and then fixed by heating, pressure, heating and pressurization or solvent vapor to obtain a toner image.

  As a developing device used in such an image forming method, a developing blade made of rubber or metal such as a toner layer thickness regulating member for regulating the toner coating amount is generally provided on the surface of a developing sleeve such as a toner carrier. A device having a configuration of contacting is known.

  The friction between the developing blade and the toner and / or the friction between the developing sleeve and the toner gives a positive or negative charge to the toner. Further, the toner is thinly applied to the surface of the developing sleeve by the developing blade, and is developed by flying or adhering to the electrostatic latent image on the surface of the electrostatic latent image carrier facing the developing sleeve.

  In such an image forming method, when magnetic toner is used, a magnet is provided in the developing sleeve, the toner is attracted to the developing sleeve by the magnetic force of the magnet, and the toner is supplied onto the developing sleeve. When the magnetic binding force that holds the toner on the developing sleeve is too strong, the toner circulation is likely to be insufficient, and the sleeve ghost and the rise and fall phenomenon of the image density due to the charge-up of the toner are increased. Such a problem is likely to occur. Patent Documents 1 and 2 propose a circulation regulating member that regulates toner circulation. In the present invention, a circulation regulating member having a free end is provided in the developing container, and by creating a small circulation of the toner in the vicinity of the developing sleeve, the charge amount of the toner is made uniform and the effect of suppressing the sleeve ghost is exhibited. ing. However, in recent image forming apparatuses with long life and large capacity, it is insufficient from the viewpoint of general circulation in the developing container during long-term durability of the toner, and image density reduction due to toner deterioration due to long-term durability. There is room for improvement. In addition, when the toner charge amount is insufficient, there is a problem that the paper is smeared due to toner scattering.

On the other hand, as a recent technical direction of an image forming apparatus, in addition to high definition, high quality, and high image quality, further high speed and long-term high reliability are required. In order to achieve a high-resolution and high-definition development system, development of toners having high development characteristics such as a reduction in toner particle size, sharpening of particle size distribution, and addition of a surface modification process are in progress. In particular, as one of shape control techniques for improving toner transfer efficiency, dot reproducibility, and the like, the shape of toner has been made close to a sphere in recent years. However, a toner having a smaller particle size and a spheroidized shape than those of conventional toners tends to be densely packed, and therefore a developer system that controls toner circulation suitable for the powder characteristics is required. Yes.
JP 2006-84560 A JP 2006-84561 A

  The object of the present invention is to suppress the generation of sleeve ghost even in a large-capacity and high-speed development process, to prevent the rise and fall of image density, to suppress paper stains due to toner scattering, and to achieve a stable and long-term high performance. The object is to provide a toner capable of obtaining a quality image.

  Another object of the present invention is to provide an image forming method using the above toner.

  Another object of the present invention is to provide a process cartridge having the above toner.

  The above problems are solved by the present invention described below.

That is, the present invention includes at least a stirring step in which the toner is stirred by the stirring member, a transporting step in which the toner is carried on the toner carrier, and a layer thickness of the toner on the toner carrier. A toner layer thickness regulating step for regulating by the regulating member, and an upper end and a lower end of the toner layer thickness regulating member that are in non-contact with the toner layer thickness regulating member, on the upper end of the toner layer thickness regulating member And a toner used in an image forming method in which the toner is circulated by a toner circulation guide member having a length from the upper end to the lower end of 3 mm or more, and the toner includes at least a binder resin And toner particles containing a colorant and inorganic fine particles, and the following formulas (1) and (2):
600 (mJ) ≦ E ≦ 1500 (mJ) (1)
500 (mJ) ≦ (E−Ea) (2)
(In the formulas (1) and (2), E (mJ) vertically enters the toner powder layer in the container while rotating the peripheral speed of the outermost edge of the propeller blade at 100 mm / sec. The measurement starts from a position 100 mm from the bottom surface of the toner powder layer, and represents the sum of the rotational torque and the vertical load obtained when the toner powder is moved to a position 10 mm from the bottom surface. Ea is a porous plate at the bottom of the container. The toner represents a sum of rotational torque and vertical load in a ventilation state in which dry air having a flow rate of 0.20 mm / s is sent therefrom).

The present invention also includes at least a stirring step in which the toner is stirred by a stirring member, a transporting step in which the toner is carried on a toner carrier, and a layer thickness of the toner on the toner carrier. A toner layer thickness regulating step for regulating by the regulating member, and an upper end and a lower end of the toner layer thickness regulating member that are in non-contact with the toner layer thickness regulating member, on the upper end of the toner layer thickness regulating member And a circulation step in which the toner is circulated by a toner circulation guide member having a length from the upper end to the lower end of 3 mm or more, wherein the toner contains at least a binder resin and a colorant. It has toner particles and inorganic fine particles, and has the following formulas (1) and (2)
600 (mJ) ≦ E ≦ 1500 (mJ) (1)
500 (mJ) ≦ (E−Ea) (2)
(In the formulas (1) and (2), E (mJ) vertically enters the toner powder layer in the container while rotating the peripheral speed of the outermost edge of the propeller blade at 100 mm / sec. The measurement starts from a position 100 mm from the bottom surface of the toner powder layer, and represents the sum of the rotational torque and the vertical load obtained when the toner powder is moved to a position 10 mm from the bottom surface. Ea is a porous plate at the bottom of the container. And an image forming method characterized by satisfying the sum of the rotational torque and the vertical load in a ventilation state in which dry air having a flow rate of 0.20 mm / s is sent therefrom. .

Further, the present invention regulates at least the stirring member for stirring the toner, the rotatable toner carrier for carrying and transporting the toner, and the layer thickness of the toner on the toner carrier. A toner cartridge for regulating the thickness of the toner layer, and a toner circulation guide member having an upper end and a lower end in a non-contact manner on the upper end of the toner layer thickness regulating member on the side of taking in the toner, The toner has toner particles containing at least a binder resin and a colorant, and inorganic fine particles, and has the following formulas (1) and (2):
600 (mJ) ≦ E ≦ 1500 (mJ) (1)
500 (mJ) ≦ (E−Ea) (2)
(In the formulas (1) and (2), E (mJ) vertically enters the toner powder layer in the container while rotating the peripheral speed of the outermost edge of the propeller blade at 100 mm / sec. The measurement starts from a position 100 mm from the bottom surface of the toner powder layer, and represents the sum of the rotational torque and the vertical load obtained when the toner powder is moved to a position 10 mm from the bottom surface. Ea is a porous plate at the bottom of the container. And represents the sum of the rotational torque and the vertical load in a ventilation state in which dry air with a flow rate of 0.20 mm / s is sent from there.) A process cartridge is provided.

  Suppresses the occurrence of sleeve ghost even in large-capacity and high-speed development processes, prevents image density from rising or falling, prevents paper contamination due to toner scattering, and provides a stable, high-quality image over the long term. It was possible to provide a toner that can be used.

The toner of the present invention is a toner having toner particles containing at least a binder resin and a colorant and inorganic fine particles and satisfying the following formulas (1) and (2).
600 (mJ) ≦ E ≦ 1500 (mJ) (1)
500 (mJ) ≦ (E−Ea) (2)
In the formulas (1) and (2), E (mJ) vertically enters the toner powder layer in the container while rotating the peripheral speed of the outermost edge of the propeller blade at 100 mm / sec. Measurement is started from a position of 100 mm from the bottom surface of the toner powder layer, and represents the sum of rotational torque and vertical load obtained when entering from the bottom surface to a position of 10 mm. Ea is a porous plate at the bottom of the container. Represents the sum of the rotational torque and the vertical load in the aerated state where dry air with a flow rate of 0.20 mm / s is sent.

In the present invention, the powder characteristics of the toner are measured by using a powder fluidity analyzer, powder rheometer FT-4 (manufactured by Freeman Technology) (hereinafter sometimes abbreviated as FT-4). did. There are various conventionally known measuring methods for evaluating powder characteristics, and in particular, fluidity. For example, a powder tester (manufactured by Hosokawa Micron) can measure the angle of repose, the degree of compression, the spatula angle, the degree of uniformity, the degree of aggregation, and the like. However, these measurement results have not been able to evaluate the fluidity of the powder in the static state and the dynamic state under the same conditions. For this reason, when the toner used in the image forming apparatus having the toner conveying member as in the present invention is evaluated, sufficient knowledge may not be obtained. In particular, evaluation of toner fluidity was insufficient in an image forming apparatus capable of accommodating a large amount of toner. The toner in the actual image forming apparatus repeats the stirring state and the pause state during development. Therefore, it is possible to simultaneously evaluate both the static state and the dynamic state of the toner. The FT-4 used in the measurement of the present invention can obtain information on the rotational torque and vertical load applied to each of the toners in the states (i) to (iii) below.
(I) Toner in a state where stirring starts from a stationary state.
(Ii) Toner in a state where a constant flow of dry air is vented, that is, in a state where stirring is continuously performed.
(Iii) Toner that is further agitated from the state of being agitated In particular, toner filled in a large-capacity image forming apparatus is likely to be uneven in the circulation state in the apparatus, and therefore the fluidity of toner from various states It is thought that control of the above becomes an effective means.

<Measuring method of E, Ea and Ed>
In the present invention, E (mJ), Ea (mJ), and Ed (mJ) are measured by a fluidity measurement method using a rotary blade. As the measuring device, for example, a powder fluidity analyzer, powder rheometer FT-4 (manufactured by Freeman Technology) (hereinafter sometimes referred to as “FT-4”) may be used.

  The device moves the blades through the powder sample, causing a constant flow measurement and pattern flow. The particles in the sample flow when the blade is in close proximity, and after passing, the blade falls and then rests again. The energy required for the blade to move through the powder is calculated, and from this value the various fluidity indices are calculated. The blade is a propeller type, and at the same time it rotates, it moves in the planting or downward direction, so that the tip draws a helix. The angle and speed of the spiral path of the blade can be adjusted by changing the rotational speed and the vertical movement. When the blade moves along the clockwise spiral path, it acts to mix the powder uniformly. Conversely, when moving along a counterclockwise spiral path, the blade will receive resistance from the powder.

  Specifically, the measurement is performed by the following operation. In all operations, the propeller blade is a 48 mm diameter blade dedicated to FT-4 measurement (see Fig. 5). A rotation axis exists in the normal direction at the center of the blade plate of 48 mm x 10 mm. The outer edge portion (24 mm from the rotating shaft) is 70 ° and the portion 12 mm from the rotating shaft is 35 °, which is smoothly twisted counterclockwise and made of SUS, model number: C210. May be abbreviated as “blade”).

  First, a FT-4 measurement dedicated 50mm x 160ml split container (model number: C203, 82mm height from the bottom of the container to the split part. The material is glass, hereinafter may be abbreviated as container) at 23 ° C, 60% environment. The toner powder layer is formed by adding 150 g of toner left for 3 days or more.

(1) Conditioning operation (a) The rotational speed of the blade (peripheral speed of the outermost edge of the blade) is 60 (mm / sec), the approach speed in the vertical direction to the powder layer is the outermost edge of the moving blade The angle formed by the locus drawn by the powder layer surface (hereinafter may be abbreviated as “seen angle”) is 5 deg. The blade is advanced from the surface of the powder layer to the position 10 mm from the bottom surface of the toner powder layer in the rotation direction (the direction in which the body layer is loosened).

  Thereafter, the blade rotation speed is 60 (mm / sec), the vertical approach speed to the powder layer is 2 (deg), and the rotation angle is clockwise with respect to the powder layer surface. Then, the blade is advanced from the bottom surface of the toner powder layer to a position of 1 mm.

  Thereafter, the toner powder is rotated clockwise with respect to the surface of the powder layer at a rotation speed of the blade of 60 (mm / sec) and an angle forming the extraction speed from the powder layer of 5 (deg). The blade is moved to a position of 100 mm from the bottom of the layer and extracted.

When the extraction is completed, the toner attached to the blade is wiped off by rotating the blade alternately in small clockwise and counterclockwise directions.
(B) By performing the series of operations (1) to (a) five times, the air entrained in the toner powder layer is removed, and a stable toner powder layer is formed.

(2) Split operation A toner powder layer having the same volume is formed by scraping the toner powder layer at the split portion of the above-described cell dedicated to FT-4 measurement and removing the toner on the powder layer.

(3) Measurement operation (i) Measurement of E (a) The same operation as (1)-(a) above is performed once.
(B) Next, the rotation speed of the blade is 100 (mm / sec), the vertical approach speed to the powder layer is an angle of 5 (deg), and it is counterclockwise with respect to the powder layer surface. In the rotational direction (the direction in which the powder layer is pushed in by the rotation of the blade), the blade is advanced to a position 10 mm from the bottom surface of the toner powder layer.

  Thereafter, the blade rotation speed is 60 (mm / sec), the vertical approach speed to the powder layer is 2 (deg), and the rotation angle is clockwise with respect to the powder layer surface. Then, the blade is advanced from the bottom of the powder layer to a position of 1 mm.

  Thereafter, the rotation speed of the blade is 60 (mm / sec), the angle forming the vertical extraction speed from the powder layer is 5 (deg), and in the clockwise rotation direction with respect to the powder layer surface, The blade is extracted from the bottom surface of the powder layer to a position of 100 mm.

When the extraction is completed, the toner attached to the blade is wiped off by rotating the blade alternately in small clockwise and counterclockwise directions.
(C) The above series of operations (b) is repeated seven times.

In the above operation (c), it is obtained when the blade enters the position from 100 mm to 10 mm from the bottom surface of the toner powder layer when the rotation speed of the seventh blade is 100 (mm / sec). Let E be the sum of rotational torque and vertical load.
(Ii) Measurement of Ea FT-4 measurement dedicated 50 mm × 200 ml container (model number: C200 and C620 (bottom plate for aeration). Height: 100 mm. Material is glass, hereinafter may be abbreviated as aeration container) at 23 ° C. A toner powder layer is formed by adding 150 g of toner left in a 60% environment for 3 days or more.
(A) The toner powder for which the measurement of E has been completed is put into an aeration container, and the above operations (1) to (a) are performed once.
(B) Next, dry air is gradually aerated from the porous plate at the bottom of the container so that the flow rate becomes 0.20 (Mm / sec). At this time, a dedicated ventilation unit for FT-4 measurement is used.
(C) The above operations (i) and (b) are performed once in a state where dry air has become familiar to the toner.
(D) Toner powder layer when dry air with a flow rate of 0.20 (Mm / sec) is ventilated and the blade rotation speed is 100 (mm / sec) after the operation of (c) above. Let Ea be the sum of rotational torque and vertical load obtained when the blade is moved from 100 mm to 10 mm from the bottom.
(Iii) Measurement of Ed After the operations of (a), (ii) and (d), the supply of dry air is stopped, and at the same time, the operations of (i) and (b) are performed four times in succession. The sum of rotational torque and vertical load obtained when the blade enters from the surface of the toner powder layer to the position of 10 mm from the bottom surface when the rotation speed of the blade is 100 (mm / sec). Let it be Ed.

  In the case of 600 (mJ) ≦ E ≦ 1500 (mJ), it is indicated that a large torque is applied when the stirring of the toner is stopped, that is, when the stirring is started from a dense state where the toner is deaerated. .

  In the case of 500 (mJ) ≦ (E−Ea), it is indicated that the difference between the torque applied when starting the agitation of the toner and the torque applied when the toner is agitated and containing air is large. This indicates that the toner in the continuous stirring state is more likely to circulate with better fluidity than in the stationary state. Once fluidity is imparted, the torque required for toner agitation is considered to be sufficiently small.

  The toner that satisfies the above formulas (1) and (2) indicates that the difference between the torque applied in the non-ventilated state and the torque applied in the vented state is large.

  In a large-capacity developer container, in order to sequentially supply fresh toner in the developer container and a small circulation for imparting frictional charge necessary for development to the toner in the vicinity of the developing sleeve and the toner layer thickness regulating member And a general circulation. By appropriately performing the small circulation and the large circulation of the toner, a stable image quality can be obtained for a long time. In particular, in the case of magnetic one-component toner, which has a higher specific gravity than non-magnetic toner, in order to sufficiently circulate the toner in the image forming apparatus having a large-capacity developing container, It was necessary to complicate the structure of the stirring member, such as increasing the number. If the configuration of the stirring member is changed in this way, the cost and the size of the printer main body must be increased.

  The large torque applied at the start of stirring as shown by the formula (1) means that the toner is easily subjected to the transport force from the stirring member, and the force to send out the toner not directly receiving the transport force of the stirring member from the toner. I can tell enough. That is, the toner satisfying the formula (1) means that the toner has excellent stirring efficiency. It becomes possible to make stirring simpler by being excellent in the efficiency of stirring. In addition, even when the initial torque is high as in the formula (1), the toner that can have high fluidity as in the formula (2) is a toner circulation guide that regulates the circulation of the toner in the developing container in addition to the stirring. This is effective for realizing the movement of the toner along the member.

  In the case of E <600 (mJ), it is indicated that the torque applied when starting stirring is small. In such a case, the toner hardly conveys the conveying force from the agitating member, and the toner cannot be circulated efficiently and the image density is likely to be thin due to long-term durability deterioration of the toner.

  In the case of 1500 (mJ)> E, it shows that the torque applied when starting stirring is large. In such a case, the toner once pushed in does not easily recover the fluidity and easily causes a thin image density due to the deterioration of the toner. In order to improve the circulation of the toner, it is necessary to increase the thickness of the stirring member or to increase the toner conveying force by stretching, but on the other hand, coarse particles are easily granulated by the stirring member in the developing container. It may create a cause.

  In addition, when (E−Ea) <500, the toner does not have sufficient fluidity even when agitated, and if the toner is packed in the developing unit, insufficient supply of toner to the developing sleeve occurs. In this case, a fading phenomenon in which the image is stripped is caused, and the image density is easily lowered. Further, when the portion where the toner tends to stay is in the developing container, the fluidity of the toner is lowered, and the pushed-in toner is likely to cause a thin density due to durability deterioration.

  The weight average particle size (D4) of the toner particles of the present invention is preferably 3.0 μm or more and 8.0 μm or less, more preferably 3.0 μm or more and 6.5 μm or less. When the weight average particle diameter (D4) of the toner particles is less than 3.0 μm, not only fogging and scattering are likely to occur, but also the toner handling property tends to be poor. When the weight average particle diameter (D4) of the toner particles is larger than 8.0 μm, it is not preferable in terms of high image quality such as fine line reproducibility, and the toner consumption tends to increase. Further, the content of particles having a particle size of 2.00 μm or more and 4.00 μm or less in the number distribution of toner particles is preferably 1% by number to 30% by number, and more preferably 1% by number to 25% by weight. is there. To make the content of particles having a particle size of 2.00 μm or more and 4.00 μm or less in the number distribution of toner particles less than 1% by number is not practical because it is necessary to repeat a classification step in toner production. When it exceeds 30% by number, the frictional charge of the toner becomes non-uniform and fogging tends to deteriorate.

  The weight average particle diameter (D4) of the toner particles can be measured using Coulter Multisizer II (manufactured by Coulter). In the present invention, measurement was performed by connecting a number distribution and volume distribution interface (manufactured by Nikka) and a personal computer to the Coulter Multisizer II.

  As an electrolytic solution used for preparation of toner particles as a test sample, a 1% by mass aqueous sodium chloride solution in which reagent primary sodium chloride is dissolved in water or ISOTONR-II (manufactured by Coulter Scientific Japan) is used. be able to. In the present invention, ISOTONR-II was used as the electrolytic solution.

  The toner as the test sample was added with 0.1 to 5 ml of a surfactant, preferably dodecylbenzenesulfonate, as a dispersant in 100 to 150 ml of the electrolytic solution, and further added with 2 to 20 mg of toner. For about 1 to 3 minutes. In the measurement of the weight average particle diameter (D4) using the Coulter Multisizer, the volume distribution and the number distribution were calculated by measuring the volume and number of toners of 2 μm or more using a 100 μm aperture as the aperture. Then, the weight-based weight average particle diameter D4 obtained from the volume distribution according to the present invention (the median value of each channel is a representative value for each channel) was obtained. In the present invention, the measurement with the Coulter Multisizer preferably measures toner particles, but the influence is ignored when the weight average particle diameter of components other than toner particles such as external additives is less than 2.00 μm. Therefore, an equivalent value can be obtained by measuring either toner or toner particles.

  In the toner particles of the present invention, it is preferable that the average circularity with an equivalent circle diameter of 3 μm or more and 400 μm or less measured by a flow type particle image measuring device is 0.940 or more and 0.970 or less. In the toner having such an average circularity, the toner charge amount distribution on the developing sleeve is likely to be uniform, and the toner coat amount is likely to be stable. Further, the contact points between the toner particles are reduced, and the fluidity of the toner during stirring is improved, which is advantageous for large circulation. When the average circularity of the toner particles is less than 0.940, the contact area between the toners or between the toner and the carrier is increased, so that the transfer efficiency is easily lowered. In addition, the charge amount distribution tends to be broad, the developability tends to decrease, and the toner consumption tends to increase. In addition, toner particles having a low degree of circularity are nearly indefinite, and the number of contact points between the toners increases, and the fluidity of the toner as a whole deteriorates, making it impossible to obtain toner with the desired fluidity. On the other hand, when the average circularity of the toner particles is higher than 0.970, the shape of the toner particles approaches a spherical shape, so that frictional charging between the toners or between the toner and the charge imparting member is difficult to occur, and fogging and scattering are caused. It is likely to occur and cause an unclear image.

  The ratio of the number of particles having an equivalent circle diameter of 0.25 μm to less than 3.00 μm measured by the flow particle image measuring apparatus for toner particles of the present invention is 1.0% to 12.0% by number. It is preferable. In order to adjust the ratio of the number of particles having an equivalent circle diameter of 0.25 μm or more and less than 3.00 μm to less than 1.0 number%, the productivity of the toner is remarkably lowered, which is not practical.

  On the other hand, when the ratio of the number of particles having an equivalent circle diameter of 0.25 μm or more and less than 3.00 μm of the toner is more than 12.0% by number, the fog tends to deteriorate depending on the use environment or the durable development conditions. In addition, the toner of ultra fine powder has a large amount of triboelectric charge, and due to its strong mirror power, it easily accumulates on the developing sleeve while adhering to the surface of the developing sleeve and inhibits charging of other toners to form a toner fine powder particle layer. The ghost is thought to worsen if you do. Further, the super fine powder is likely to be accumulated and adhered to the charging member, and it is easy for image defects due to charging failure to occur, sleeve ghost due to charge-up is deteriorated, and image streaks are likely to occur. Further, the circularity measured by the flow particle image measuring device for toner particles measured here is preferably measured for toner particles, but the weight average particle size of components other than toner particles such as external additives is 3 In the case of less than 0.000 μm, the influence can be ignored, so that an equivalent value can be obtained by measuring either toner or toner particles. On the other hand, when measuring the ratio of the number of particles having an equivalent circle diameter of 0.25 μm or more and less than 3.00 μm, the influence of external additives such as inorganic fine particles may not be negligible, so it is necessary to measure toner particles. is there.

  The toner circulation guide member used in the image forming method of the present invention is a non-contact upper end of the toner layer thickness regulating member on the side where the toner is taken in, has an upper end and a lower end, and the upper end and the upper end A toner circulation guide member having a distance from the lower end of 3 mm or more. As shown in FIG. 1, by arranging the toner circulation guide member near the upper portion of the developing sleeve, it is possible to provide a good image free from the occurrence of sleeve ghost.

  The reason why the sleeve ghost is improved by providing the toner circulation guide member will be described.

  When the toner carried on the developing sleeve is regulated by the toner layer thickness regulating member, the toner is frictionally charged and retains the electric charge on the toner surface. If the toner on the developing sleeve is not consumed by printing, it remains on the developing sleeve and is repeatedly triboelectrically charged by the toner layer thickness regulating member. At this time, when the toner on the developing sleeve is not consumed, the same toner is only held on the developing sleeve. However, when the toner on the developing sleeve is consumed by printing (particularly when the printing rate is 100%), if fresh toner that is not subjected to frictional charging is supplied from the image forming apparatus, the first and second rounds of the developing sleeve are supplied. It occurs that the average charged charge amount differs by eye. When the average charge amount of the toner on the developing sleeve is different, the developability, that is, the image density is different, and a problem called sleeve ghost occurs. Therefore, it is necessary to prevent fresh toner with insufficient frictional charging from the developing container from being directly supplied onto the developing sleeve. Particularly in the case of a large-capacity image forming apparatus, the toner when the filling amount is large is pushed into the developing sleeve by its own weight. In this state, this problem becomes more prominent because the toner charged up repeatedly in the vicinity of the developing sleeve after being repeatedly charged and the fresh toner that is not yet sufficiently charged with frictional charging are supplied thereto. Become.

  As a solution for suppressing the sleeve ghost, as shown in FIG. 1, there is a case where a toner circulation guide member 1 is arranged near the upper portion of the developing sleeve. As shown in FIG. 1, it has been found that it is effective to dispose the toner circulation guide member 1 in the vicinity of the toner layer thickness regulating member so that the circulation (M9) is smaller in the back of the developing sleeve (space E2). This is because by arranging the toner circulation guide member 1 between the developing sleeve and the toner supply opening, toner circulation (M3 and M8) is generated so as to prevent the feeding of fresh toner, which is not sufficiently applied with frictional charging by the stirring member. Because. Therefore, it is possible to reduce the difference in the average charge amount on the developing sleeve between when the toner on the developing sleeve is consumed and when it is not. Since a small circulation (M9) of toner occurs in a space formed between the toner circulation guide member 1 and the toner layer thickness regulating member or the developing sleeve, the chance that the toner contacts the developing sleeve is appropriately increased. As a result, the difference in the average charge amount of the toner formed in the first and second rounds of the developing sleeve is reduced. On the other hand, when there is no circulation guide member, it circulates in the direction of M4 from M1 to M2, M8, M3 and the gravity of the toner, and a part of the toner is returned to the developing container and circulates (M10). The general circulation is considered to be dominant.

  However, if the toner circulation guide member is simply disposed near the upper portion of the developing sleeve, the toner can be pushed into the small circulation space provided by the toner circulation guide member. For this reason, toner replacement is unlikely to occur, and there is a possibility that an adverse effect such as low density due to toner packing may occur. In order to solve the problem, the toner circulation guide member is opened on the upper side where the toner is taken in and in the vicinity of the developing sleeve, so that the toner is released without being pushed in (M7), thereby suppressing the deterioration of the toner. It is considered possible.

  When the upper side of the toner circulation guide member that takes in the toner is closed, the toner is packed and the problem of low density tends to occur. This is more likely to cause the above problem in an image forming apparatus having a large capacity developer container with a large amount of toner filling. Further, when the toner is disposed at a position far away from the developing sleeve, it is easy to supply fresh toner with insufficient frictional charging, and image problems such as sleeve ghost and scattering are likely to occur.

  By using a specific toner in the above-described image forming method, the present inventors suppress the occurrence of sleeve ghost even in a large-capacity and high-speed development process, and there is no rise or fall phenomenon of image density, and long-term. It has been found that obtaining a stable and high-quality image is particularly effective.

  The toner satisfying the above-mentioned formulas (1) and (2) is adapted to a change from a densely tightened state to a state in which air-containing fluidity is good, and exhibits a behavior of being pushed in and loosened. It can be said that it is suitable for. When the toner circulation guide member is used, the developer sleeve, the toner layer thickness regulating member, and the toner circulation guide member pass through the space in a dense state. Contact and efficiently apply triboelectric charge. Further, immediately after passing between the developing sleeve, the toner layer thickness regulating member, and the toner circulation guide member, it immediately returns to a fluid-rich state containing air, that is, the toner powder pressure is instantaneously released and reduced. It is thought that it shows the behavior of repeating the circulation. As described above, after the toner is given frictional charge, the small circulation is repeated in a short time, so that the ratio of the uncharged toner is reduced. Accordingly, the time required for the toner on the developing sleeve to have proper frictional charging is shortened. Therefore, the toner rises quickly. As described above, according to the present invention, by using a specific toner in the above-described image forming method, it is possible to obtain a high density from the initial use and to obtain an image having a stable density from the initial stage without a density rise. all right.

The toner of the present invention preferably further satisfies the following formula (3).
0.10 <(Ed / E) <0.70 (3)
In the expression (3), Ed (mJ) is a flow of dry air whose flow rate is controlled into the powder phase of the toner in the container, and when the E reaches a state of 30 (mJ) or less, the ventilation is performed. The measurement is stopped, the same measurement as E is repeated four times, and the sum of the rotational torque and the vertical load obtained by the fourth measurement is represented.

  Formula (3) shows the deaeration state of air from the toner after the aeration is stopped from the aeration state of the toner. The larger the value of Ed / E, the quicker the return to the deaerated state, the shorter the time to return from the agitated state to the dense state, and the greater the torque required for agitation again. Conversely, when the value of Ed / E is small, the return to the deaerated state is slow, indicating that the fluidity is maintained for a while even after the stirring is stopped from the stirred state.

  When the toner satisfies 0.10 <(Ed / E) <0.70, the toner exhibits fluidity even when stirring is stopped from a state where the toner is stirred in the developing container during development. Easy to hold. For this reason, even if the image is intermittently output, the toner hardly deteriorates and a stable density can be maintained for a long time. In addition, it is easy to handle and preferably maintain fluidity for a certain period of time in the manufacturing process until the toner is filled into the image forming apparatus.

  In the case of (Ed / E) ≦ 0.10, it indicates that the toner maintains fluidity, but the toner that is not degassed even after a long time is often in a dense state. Problems such as poor filling efficiency are likely to occur.

  In the case of 0.70 ≦ (Ed / E), it can be considered that when stirring is stopped, it takes a short time until clogging is likely to occur. When images are output intermittently, the toner is sheared every time stirring and stopping are repeated, which tends to cause a decrease in density due to toner deterioration.

  Further, the structure of the toner circulation guide member preferable for achieving the object in the present invention will be described in detail below.

  In addition, the toner circulation guide member used in the present invention is such that the upper end with respect to the straight line A connecting the rotation center of the toner carrier and the end portion of the toner layer thickness regulating member with respect to the rotation direction of the toner carrier. The lower end is present between −30 ° and 15 °, and the distance between the toner circulation guide member and the toner carrier is 1 mm or greater and 7 mm or less. The inclination of the straight line B with respect to the straight line A when the straight line B connecting the lower ends is centered on the intersection with the straight line A is 0 ° or more and 35 ° or less on the toner carrier side, and 0 in the direction far from the toner carrier. It is preferable that the angle is in the range of not less than and not more than 45 °.

  When the upper end of the toner circulation guide member is at a position that is not less than −15 ° and not more than 15 ° with respect to the rotation direction of the toner carrier, it is effective in suppressing the occurrence of sleeve ghost. When the upper end is on the plus side with respect to + 15 °, the toner is likely to be clogged, and vertical stripes due to toner deterioration are likely to occur. On the other hand, when the upper end is on the minus side with respect to −15 °, the effect on the sleeve ghost is lost. The space between the developing sleeve, the toner layer thickness regulating member, and the toner circulation guide member becomes too large to prevent sufficient small circulation, and the amount of toner reaching the toner circulation guide member is reduced, so that a lot of fresh toner is supplied to the developing sleeve. It will be. That is, the effect of the toner circulation guide member itself is small.

  When the lower end of the toner circulation guide member is -30 ° or more and 0 ° or less, it is effective in suppressing the generation of sleeve ghost. However, if the toner circulation guide member is in a positive angle region from 0 °, the effect on the sleeve ghost is lost. End up. This is because the flow of the toner that has been circulated through a small amount and is triboelectrically charged cannot be supplied well in the vicinity of the developing sleeve and the toner layer thickness regulating member. When it is on the minus side from −30 °, the deterioration of the toner is easily accelerated and the density is lowered. The toner circulation guide member is positioned below the developing sleeve and the toner layer thickness regulating member, and the toner staying below due to its own weight repeatedly contacts the developing sleeve and the toner layer thickness regulating member to cause toner deterioration.

  When the shortest distance between the toner circulation guide member and the toner carrier is 1 mm or more and 7 mm or less, it is more effective for suppressing the occurrence of sleeve ghost. When the shortest distance is larger than 7 mm, it is difficult to obtain the effect of suppressing the occurrence of sleeve ghost. Further, when the shortest distance is larger than 7 mm, the space between the developing sleeve, the toner layer thickness regulating member, and the toner circulation guide member becomes too large, and small circulation hardly occurs. When the shortest distance is less than 1 mm, the space between the developing sleeve, the toner layer thickness regulating member, and the toner circulation guide member is very small, and the toner may not easily circulate.

  Further, with the intersection of the straight line B and the straight line A as the center, the inclination of the straight line B with respect to the straight line A is 0 ° or more and 35 ° or less on the toner carrier side, and 0 ° or more and 45 ° in the direction away from the developing sleeve. It is preferable to be within the following range. When this numerical range is satisfied, it is effective in suppressing the occurrence of sleeve ghost. If the inclination is greater than 35 ° toward the developing sleeve, sleeve ghost may be difficult to suppress. This is because the angle at which the toner that has passed through the space between the developing sleeve, the toner layer thickness regulating member, and the toner circulation guide member returns to the downstream side in the developing sleeve rotation direction, and the chance of applying frictional charge to the toner is reduced. It is. In addition, when the inclination is greater than 45 ° in the far direction from the developing sleeve, the toner that has passed through the space between the developing sleeve, the toner layer thickness regulating member, and the toner circulation guide member is less likely to return and forms a small circulation. It becomes difficult to suppress the sleeve ghost.

  The shape of the toner circulation guide member of the present invention is preferably a plate shape, but is not particularly limited. The material of the toner circulation guide member is preferably molded, but is not particularly limited as long as it is a non-magnetic material. It is sufficient that the toner pressure below the toner circulation guide member and the toner repelled at the contact portion between the developing sleeve and the toner layer thickness regulating member can be returned to the corresponding contact portion. What is necessary is just to have the surface which implement | achieves this effect | action, making it an open system.

  The method for arranging and supporting the toner circulation guide member in the developing device is not particularly limited as long as it is an arrangement method that does not impede toner circulation.

  Further, the toner circulation guide member of the present invention may also perform a residual amount sequential residual detection in a capacitance detection type. The toner remaining amount sequential detection means that the remaining amount is sequentially detected as the toner is consumed. A plate antenna (hereinafter also referred to as PA), which is a toner circulation guide member that also serves as a residual check for the remaining amount of toner, is installed so that the toner in the developer container is fluid and the degree of toner reduction can be seen. This is preferable because the configuration can be simplified. The material of PA may be any material as long as it is a plate having good conductivity, but is preferably a material that does not adversely affect the toner and is strong against environmental conditions such as humidity. Further, a plurality of PAs may be provided in the developing container. And at least one side of PA has a shape that can be energized from the outside. This connectable portion may be directly connected by a conductive wire or the like, or may be skewered with a conductive pin shape from the side of the cartridge. It is preferable to take a form in which a pin-shaped object is pierced through the side wall of the cartridge into the raising part. Further, the toner remaining amount detection by the developing sleeve and PA measures the remaining amount of toner using a developing bias applied to the developing sleeve. The voltage value induced in PA by the developing bias applied to the developing sleeve is read. If the dielectric constant varies depending on the remaining amount of toner between the developing sleeve and PA, the voltage value induced in PA also varies. The remaining toner level is detected by looking at the different voltage values.

  In the present invention, the toner layer thickness regulating blade may be roughened. When the surface is roughened, the toner layer thickness regulating blade has irregularities on the surface, so that the charge imparting power to the toner coated on the developing sleeve can be further increased. Therefore, the image density becomes good even after long-term use, and the toner has good chargeability, so that it is easy to obtain an excellent image quality with little fog.

  The material of the toner layer thickness regulating blade member used in the present invention is not particularly limited, and examples thereof include the following. Urethane rubber, polyamide resin, polyamide elastomer, silicone rubber and silicone resin. Among these, urethane rubber is preferable for obtaining the effects of the present invention. The support member of the toner layer thickness regulating blade is preferably made of a metal flat plate, a resin flat plate, more specifically, a stainless steel plate, a phosphor bronze plate, an aluminum plate, or the like. An additive such as a conductive material can be added to the main material of the blade member. In addition, the support member and the blade member can be bonded by, for example, an adhesive such as hot melt.

  When a rubber material is used as the toner layer thickness regulating member, the rubber hardness is preferably 40 ° or more and 100 ° or less according to JIS A. More preferably, it is A45 ° to 95 ° in JIS, and more preferably 50 ° to 90 °. If the rubber hardness is less than 40 °, the contact pressure with respect to the developing sleeve tends to be insufficient, and the toner may not be sufficiently charged and the image density may be lowered. On the other hand, when the rubber hardness exceeds 100 °, the contact pressure becomes too high, causing toner deterioration and easily causing poor charging, so that the image density is likely to decrease.

  Further, in the present invention, a preferable toner configuration for achieving the object will be described in detail below.

  Examples of the binder resin used in the toner of the present invention include vinyl resins, polyester resins, epoxy resins, polyurethane resins, and the like, but are not particularly limited, and conventionally known resins can be used. Among them, it is preferable to contain a polyester resin because of good chargeability and quick rise, and sharp melt and particularly excellent low-temperature fixability. As the binder resin, these resins can be used alone or in combination of two or more.

  The composition of the polyester resin is as follows.

  Examples of the divalent alcohol component include 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, and bisphenol represented by the formula (A) and derivatives thereof;

(In the formula, R is an ethylene or propylene group, x and y are each an integer of 0 or more, and the average value of x + y is 0 to 10.)
And diols represented by the formula (B);

(X ′ and y ′ are integers of 0 or more, and the average value of x + y is 0 to 10.)
Is mentioned.

  Examples of the divalent acid component include benzene dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and phthalic anhydride or anhydrides thereof, lower alkyl esters; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid. Acids or anhydrides thereof, lower alkyl esters; alkenyl succinic acids or alkyl succinic acids such as n-dodecenyl succinic acid and n-dodecyl succinic acid, or anhydrides, lower alkyl esters thereof; fumaric acid, maleic acid, citraconic acid, itaconic acid Dicarboxylic acids such as unsaturated dicarboxylic acids or anhydrides thereof, lower alkyl esters;

  Further, it is preferable to use a trivalent or higher alcohol component or a trivalent or higher acid component that acts as a crosslinking component alone or in combination.

  Examples of the trihydric or higher polyhydric alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butane. Triol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxybenzene, etc. Is mentioned.

  Examples of the trivalent or higher polycarboxylic acid component in the present invention include trimellitic acid, pyromellitic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5, 7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylene Carboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, empole trimer acid, and their anhydrides, lower alkyl esters;

(Wherein X is an alkylene group or alkenylene group having 5 to 30 carbon atoms having one or more side chains having 3 or more carbon atoms) and the like, and their anhydrides, lower alkyl esters and the like polyvalent Examples thereof include carboxylic acids and derivatives thereof.

  The alcohol component used in the present invention is 40 to 60 mol%, preferably 45 to 55 mol%, and the acid component is 60 to 40 mol%, preferably 55 to 45 mol%. Moreover, it is preferable that the polyvalent component more than trivalence is 5-60 mol% in all the components.

  The polyester resin is usually obtained by a generally known condensation polymerization.

  In the present invention, in addition to the polyester resin, the following vinyl resin may be used as the binder resin.

  Examples of vinyl resins include styrene; o-methylstyrene, m-methylstyrene, p-methylenestyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethyl. Styrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene , Styrene derivatives such as pn-dodecylstyrene; ethylene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; unsaturated polyenes such as butadiene; vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, etc. Of vinyl halides; vinyl acetate, vinyl propionate, benzo Vinyl esters such as vinyl acid; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, Α-methylene aliphatic monocarboxylic acid esters such as phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, acrylic Acrylic acid esters such as n-octyl acid, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; vinylmethyl Vinyl ethers such as ether, vinyl ethyl ether and vinyl isobutyl ether; Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone N-vinyl compounds such as; vinyl naphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, acrylamide; esters of α, β-unsaturated acids, diesters of dibasic acids; acrylic acid, methacrylic acid, Acrylic acid such as α-ethylacrylic acid, crotonic acid, cinnamic acid, vinyl acetic acid, isocrotonic acid, angelic acid and α- or β-alkyl derivatives thereof; fumaric acid, maleic acid, citraconic acid, alkenyl succinic acid, itaconic acid And polymers using vinyl monomers such as unsaturated dicarboxylic acids such as mesaconic acid, dimethylmaleic acid and dimethylfumaric acid, and monoester derivatives or anhydrides thereof. In the vinyl resin, vinyl monomers as described above are used alone or in combination of two or more. Among these, a combination of monomers that is a styrene copolymer or a styrene-acrylic copolymer is preferable.

  The method for synthesizing a binder resin composed of a vinyl-based homopolymer or copolymer is not particularly limited, and various conventionally known production methods can be used. For example, a bulk polymerization method, a solution polymerization method, Polymerization methods such as suspension polymerization and emulsion polymerization can be used. When a carboxylic acid monomer or an acid anhydride monomer is used, it is preferable to use a bulk polymerization method or a solution polymerization method because of the properties of the monomer.

  In addition, the binder resin used in the present invention may be a polymer or copolymer cross-linked with a cross-linkable monomer as exemplified below if necessary. As the crosslinkable monomer, a monomer having at least two crosslinkable unsaturated bonds can be used. As such a crosslinkable monomer, various monomers as shown below are conventionally known and can be suitably used for the developer of the present invention.

  Examples of the crosslinkable monomer include divinylbenzene and divinylnaphthalene as aromatic divinyl compounds; diacrylate compounds linked with an alkyl chain such as ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and those obtained by replacing acrylate of the above compounds with methacrylate; ether bond Examples of diacrylate compounds linked by an alkyl chain containing, for example, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol Coal # 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate and the above compounds in which the acrylate is replaced with methacrylate; diacrylate compounds linked by a chain containing an aromatic group and an ether bond For example, polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,2-bis (4-hydroxyphenyl) propane diacrylate and the above The thing which replaced the acrylate of the compound with the methacrylate is mentioned; As a polyester type diacrylate, a brand name MANDA (Nippon Kayaku) etc. are mentioned, for example.

  Polyfunctional cross-linking agents include pentaerythritol triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate, and acrylates of the above compounds replaced with methacrylate; triallylcia Examples thereof include nurate and triallyl trimellitate.

  Among the above-mentioned crosslinkable monomers, aromatic divinyl compounds (particularly divinylbenzene), aromatic groups and ether bonds are preferred as binder resins from the viewpoint of fixability and offset resistance of the resulting toner. Examples include diacrylate compounds linked by a chain.

  Moreover, it is preferable to adjust the usage-amount of the said crosslinking agent by the kind of monomer which is going to bridge | crosslink, the physical property calculated | required by binder resin, etc. For example, the crosslinking agent is preferably used in an amount of 0.01 to 10 parts by mass, more preferably 0.03 to 5 parts by mass, with respect to 100 parts by mass of other monomer components that generally constitute the binder resin.

  In the present invention, a vinyl polymer homopolymer or copolymer other than the above, polyester, polyurethane, epoxy resin, polyvinyl butyral, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, Aromatic petroleum resin or the like can be used by mixing with the above-described binder resin as necessary. When two or more kinds of resins are mixed and used as the binder resin, it is more preferable to mix those having different molecular weights at an appropriate ratio.

  The binder resin used in the toner of the present invention preferably has a glass transition temperature (Tg) of 45 to 80 ° C., more preferably 50 to 70 ° C., from the viewpoints of storage stability and fixability.

  The measuring method of the glass transition temperature (Tg) of the binder resin is performed according to ASTM D3418-82 using Q-1000 manufactured by TA Instruments. The DSC curve used in the present invention is a DSC curve measured when the temperature is raised at a rate of 10 ° C./min after raising and lowering the temperature once and taking a previous history. In the DSC curve at the time of temperature increase obtained at this time, the temperature at the intersection of the line connecting the midpoint of the baseline before and after the change in specific heat and the DSC curve was defined as the glass transition temperature (Tg).

  The binder resin used in the toner of the present invention preferably has an acid value from the viewpoint of reducing environmental dependency. The acid value of the binder resin is preferably 1 to 50 (mgKOH / g).

  The hydroxyl value of the binder resin used for the toner is preferably 60 mgKOH / g or less from the viewpoint of reducing the environmental dependency.

  The toner of the present invention may contain a wax.

  The waxes used in the present invention include the following. For example, low molecular weight polyethylene, low molecular weight polypropylene, polyolefin copolymer, polyolefin wax, microcrystalline wax, paraffin wax, aliphatic hydrocarbon wax such as Fischer-Tropsch wax; oxide of aliphatic hydrocarbon wax such as oxidized polyethylene wax Or block copolymers thereof; plant waxes such as candelilla wax, carnauba wax, wax wax, jojoba wax; animal waxes such as beeswax, lanolin, spermaceti; mineral systems such as ozokerite, ceresin, petrolactam Waxes; waxes mainly composed of aliphatic esters such as montanic acid ester wax and castor wax; those obtained by partially or fully deoxidizing aliphatic esters such as deoxidized carnauba wax . Further, saturated linear fatty acids such as palmitic acid, stearic acid, montanic acid, or long-chain alkyl carboxylic acids having a long-chain alkyl group; unsaturated fatty acids such as brassic acid, eleostearic acid, and valinal acid; stearyl alcohol Saturated alcohol such as eicosyl alcohol, behenyl alcohol, cannavir alcohol, seryl alcohol, melyl alcohol, or alkyl alcohol having a long chain alkyl group; polyhydric alcohol such as sorbitol; linoleic acid amide, oleic acid amide, lauric acid Aliphatic amides such as acid amides; saturated aliphatic bisamides such as methylene bisstearic acid amide, ethylene biscapric acid amides, ethylene bislauric acid amides, hexamethylene bisstearic acid amides; Unsaturated fatty acid amides such as inamide, hexamethylenebisoleic acid amide, N, N′-dioleyl adipic acid amide, N, N′-dioleyl sebacic acid amide; m-xylene bisstearic acid amide, N, Aromatic bisamides such as N'-distearylisophthalamide; aliphatic metal salts such as calcium stearate, calcium laurate, zinc stearate and magnesium stearate (commonly referred to as metal soap); aliphatic hydrocarbons Wax grafted with a vinyl monomer such as styrene or acrylic acid; Partial esterified product of fatty acid and polyhydric alcohol such as behenic acid monoglyceride; Hydroxyl group obtained by hydrogenating vegetable oil Methyl ester compound. Specific product names of the wax include the following. Biscol (registered trademark) 330-P, 550-P, 660-P, TS-200 (Sanyo Chemical Industries), High Wax 400P, 200P, 100P, 410P, 420P, 320P, 220P, 210P, 110P (Mitsui Chemicals) ), Sazole H1, H2, C80, C105, C77 (Schumann Sazol), HNP-1, HNP-3, HNP-9, HNP-10, HNP-11, HNP-12 (Nippon Seiki Co., Ltd.), Unilin (registered trademark) 350, 425, 550, 700, Unicid (registered trademark), Unicid (registered trademark) 350, 425, 550, 700 (Toyo Petrolite), wood wax, beeswax, rice wax, candelilla wax Carnauba wax (available from Celerica NODA).

  In addition, these waxes have a sharp molecular weight distribution using a press sweating method, a solvent method, a recrystallization method, a vacuum distillation method, a supercritical gas extraction method or a melt liquid crystal deposition method, a low molecular weight solid fatty acid, a low molecular weight A solid alcohol, a low molecular weight solid compound, and other impurities are preferably used.

  When the toner of the present invention is obtained, the use of a one-component toner one-component developing system by incorporating a magnetic material eliminates the need for a carrier, which is advantageous in terms of downsizing the apparatus.

  The following are mentioned as a magnetic material in this invention. Iron oxides such as magnetite, maghemite, ferrite; metals such as iron, cobalt, nickel or these metals aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, Alloys of metals such as selenium, titanium, tungsten, vanadium and mixtures thereof.

  These magnetic materials preferably have an average particle size of 2 μm or less, more preferably 0.05 to 0.5 μm. The amount of the magnetic material contained in the toner is preferably 20 to 200 parts by mass with respect to 100 parts by mass of the resin component, and more preferably 40 to 150 parts by mass with respect to 100 parts by mass of the resin component.

  The toner of the present invention preferably contains a charge control agent.

  Examples of the charge control agent for controlling the toner to be negatively charged include the following compounds.

  Organometallic complexes and chelate compounds are effective, and there are monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid metal complexes. Others include aromatic hydroxycarboxylic acids, aromatic mono and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.

  Among these, an azo metal complex represented by the following general formula (1) or a basic organic acid metal complex represented by the following general formula (2) is preferable.

  In the above general formula (1), the coordination center metal M is particularly preferably Fe, the substituent is preferably a halogen, an alkyl group or an anilide group, and the counter ion is preferably hydrogen, an alkali metal, ammonium or aliphatic ammonium. . A mixture of complex salts having different counter ions is also preferably used.

  In the general formula (2), the coordination center metal M is particularly preferably Fe, Cr, Si, Zn or Al, and the substituent is preferably an alkyl group, anilide group, aryl group or halogen. The counter ion is preferably hydrogen, ammonium or aliphatic ammonium.

  Examples of the charge control agent for controlling the toner to be positively charged include the following compounds.

  Modified products with nigrosine and fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and onium salts such as phosphonium salts thereof. And lake pigments thereof, triphenylmethane dyes and lake pigments thereof (as rake agents, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide) Metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate, dioctyltin borate, dicyclohexyl Such diorgano tin borate of Suzuboreto; guanidine compounds, imidazole compounds. These can be used alone or in combination of two or more. Among these, triphenylmethane compounds and quaternary ammonium salts whose counter ions are not halogen are preferably used. The following general formula (3)

[Wherein R ₁ represents H or CH ₃ , and R ₂ and R ₃ represent a substituted or unsubstituted alkyl group (preferably C _{1 to} C ₄ ). ]
Monomers of monomers represented by: A copolymer with a polymerizable monomer such as styrene, acrylic acid ester or methacrylic acid ester described above can be used as a positive charge control agent. In this case, these charge control agents also have an action as a binder resin (all or a part thereof).

  In particular, a compound represented by the following general formula (4) is preferred as the positive charge control agent of the present invention.

  As a method for adding the charge control agent to the toner, there are a method of adding the toner inside the toner particles and a method of adding the toner outside the toner particles. The amount of use of these charge control agents is determined by the toner production method including the type of binder resin, the presence or absence of other additives, and the dispersion method, and is not uniquely limited. As a guide, the following amounts are preferable. That is, it is preferable that a charge control agent is 0.1-10 mass parts with respect to 100 mass parts of binder resin, More preferably, it is 0.1-5 mass parts.

  It is preferable that inorganic particles are externally added to the toner particles of the present invention. Examples of the inorganic fine particles include fine silica powder, fine titanium oxide powder, and hydrophobized products thereof. They are preferably used alone or in combination.

  Examples of the silica fine powder include both a dry process produced by vapor phase oxidation of a silicon halogen compound or dry silica called fumed silica, and wet silica produced from water glass or the like. Dry silica with fewer silanol groups on the surface and inside and no production residue is preferred.

  Further, the silica fine powder is preferably hydrophobized. The hydrophobizing treatment is applied by chemically treating with an organosilicon compound that reacts or physically adsorbs with silica fine powder. Preferable methods include a method in which a dry silica fine powder produced by vapor phase oxidation of a silicon halogen compound is treated with a silane compound or with a silane compound and simultaneously with an organosilicon compound such as silicone oil.

  The following are mentioned as a silane compound used for a hydrophobization process. Hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloro Ethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilane mercaptan, trimethylsilyl mercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyl Disiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane Siloxane.

Examples of the organosilicon compound include silicone oil. The silicone oil preferably has a viscosity at 25 ° C. of about 30 to 1,000 mm ² / s. Examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, and fluorine modified silicone oil.

  Silicone oil treatment can be performed by directly mixing silica powder treated with a silane compound and silicone oil using a mixer such as a Henschel mixer, or spraying silicone oil onto the base silica. It may be by the method. Alternatively, the silicone oil may be dissolved or dispersed in an appropriate solvent, and then mixed with the base silica fine powder to remove the solvent.

  As a preferable hydrophobizing treatment of the silica fine powder, there is a method of preparing by treating with hexamethyldisilazane and then treating with silicone oil.

  As described above, it is preferable to treat the silica fine powder with the silane compound and then oil-treat it later, so that the degree of hydrophobicity can be effectively increased.

  The silica fine powder is preferably subjected to a hydrophobization treatment, and further, an oil treatment applied to the titanium oxide fine powder, similarly to the silica-based one.

  To the toner particles of the present invention, additives other than silica fine powder or titanium oxide fine powder may be externally added as necessary.

  For example, charging aids, conductivity-imparting agents, fluidity-imparting agents, anti-caking agents, release agents at the time of heat roll fixing, resin fine particles or inorganic fine particles functioning as lubricants or abrasives can be mentioned.

  The fine resin particles preferably have an average particle size of 0.03 to 1.0 μm. Examples of the polymerizable monomer constituting the resin fine particles include the following. Styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-ethylstyrene derivatives; acrylic acid; methacrylic acid; methyl acrylate, ethyl acrylate, n-butyl acrylate, acrylic acid Acrylic esters such as isobutyl, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; methyl methacrylate, ethyl methacrylate , N-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, methacryl Dimethylaminoethyl, such as methacrylic acid esters of diethylaminoethyl methacrylate; acrylonitrile, methacrylonitrile, a monomer such as acrylamide.

  Examples of the polymerization method for producing resin fine particles from the polymerizable monomer include suspension polymerization, emulsion polymerization, and soap-free polymerization. More preferably, particles obtained by soap-free polymerization are good.

  Examples of other fine particles include the following.

  Lubricants such as poly (ethylene fluoride), zinc stearate and polyvinylidene fluoride (especially preferred is polyvinylidene fluoride); abrasives such as cerium oxide, silicon carbide and strontium titanate (especially preferred is strontium titanate); titanium oxide A fluidity-imparting agent such as aluminum oxide (in particular, a hydrophobic agent is preferred); an anti-caking agent; a conductivity-imparting agent such as carbon black, zinc oxide, antimony oxide, and tin oxide. Further, a small amount of white fine particles and black fine particles having a polarity opposite to that of the toner may be used as a developability improver.

  The inorganic fine particles contained in the toner are preferably 0.01 to 5 parts by mass, more preferably 0.01 to 3 parts by mass with respect to 100 parts by mass of the toner.

  The toner of the present invention can be produced by a known method. As a method for producing the toner of the present invention, the materials constituting the toner particles are sufficiently mixed by a ball mill or other mixer, then kneaded well using a heat kneader such as a hot roll kneader or an extruder, and after cooling and solidification. A method in which the toner is obtained by mechanically pulverizing and classifying the pulverized powder and then adding and mixing external additives is preferable.

  The equipment used for producing the toner of the present invention is not particularly limited, and examples thereof include the following.

  Henschel mixer (made by Mitsui Mining); Super mixer (made by Kawata); Ribocorn (made by Okawara Seisakusho); Nauta mixer, turbulizer, cyclomix (made by Hosokawa Micron); Pacific Kiko Co., Ltd.); Redige mixer (Matsubo Co., Ltd.).

  As a kneading machine, for example, KRC kneader (manufactured by Kurimoto Iron Works); Bus co-kneader (manufactured by Buss); TEM type extruder (manufactured by Toshiba Machine); TEX twin-screw kneader (manufactured by Nippon Steel Works) PCM kneading machine (Ikegai Iron Works); Three roll mill, mixing roll mill, kneader (Inoue Seisakusho); Needex (Mitsui Mining); MS pressure kneader, Nider Ruder (Moriyama Seisakusho) A Banbury mixer (manufactured by Kobe Steel).

  Examples of the pulverizer include an inomizer (manufactured by Hosokawa Micron); a kryptron (manufactured by Kawasaki Heavy Industries); a turbo mill (manufactured by Turbo Industry); and a super rotor (manufactured by Nisshin Engineering).

  Classifiers include, for example, a class seal, a micron classifier, a speck classifier (manufactured by Seishin Enterprise); a turbo classifier (manufactured by Nisshin Engineering); a micron separator, a turboplex (ATP), a TSP separator (manufactured by Hosokawa Micron) ); Elbow Jet (manufactured by Nippon Steel Mining Co., Ltd.), Dispersion Separator (manufactured by Nippon Pneumatic Industrial Co., Ltd.); YM Microcut (manufactured by Yaskawa Shoji Co., Ltd.).

  Examples of sieving devices used to screen coarse particles include Ultrasonic (manufactured by Sakae Sangyo Co., Ltd.); Resonator Sheave, Gyroshifter (Tokuju Kosakusha Co., Ltd.); Vibrasonic System (Dalton Co., Ltd.); Examples include a turbo screener (manufactured by Turbo Industry Co., Ltd.), a micro shifter (manufactured by Kanno Sangyo Co., Ltd.), and a circular vibrating sieve.

  Next, a method for producing toner particles using a surface modification step, which is a preferred method for obtaining the toner particles of the present invention, will be described.

  Examples of the surface modification apparatus include those shown below. Faculty (manufactured by Hosokawa Micron), Mechano-Fusion (manufactured by Hosokawa Micron), Nobilta (manufactured by Hosokawa Micron), Hybridizer (manufactured by Nara Machinery Co., Ltd.), Inomizer (manufactured by Hosokawa Micron Co., Ltd.), Mechano mill (Okada Seiko Co., Ltd.), Cryptron (Kawasaki Heavy Industries Co., Ltd.), Super Rotor (Nisshin Engineering Co., Ltd.), Turbo Mill (Turbo Industry Co., Ltd.), Tornado Mill (Nikkiso Co., Ltd.). A pulverizer or the like can also be used as the toner particle surface modifying apparatus of the present invention. In the surface modification of the toner particles, the treatment may be repeated twice or more with the same apparatus, or two or more kinds of surface modification apparatuses may be combined.

  In the surface modification apparatus, for example, Faculty (manufactured by Hosokawa Micron Corporation) has a function of removing fine powder components simultaneously with the surface modification of toner particles in the toner particle surface modification step. When using a surface modification device that can remove fine powder components at the same time as the surface modification of toner particles in this way, the raw material toner particles finely divided in the vicinity of a desired particle size are converted into fine powder and coarse particles using an airflow classifier. It is preferable to perform surface modification after removing the powder to some extent. In this case, the toner particles from which fine powder has been removed by the airflow classifier have a cumulative value of the number average distribution of toner particles of less than 4 μm in a particle size distribution measured using a Coulter counter method of 10% or more and less than 50%. Preferably, it is 15% or more and less than 45%, more preferably 15% or more and less than 30%. Setting the cumulative value of the number average distribution of toner particles of less than 4 μm in the classification step to less than 10% is not practical because the toner productivity is significantly reduced. On the other hand, when it is 50% or more, the surface modification is likely to be non-uniform, and it becomes difficult to obtain the desired toner fluidity of the present invention. Examples of the airflow classifier used in the present invention include elbow jet (manufactured by Nippon Steel Industries Co., Ltd.).

  The present invention is characterized in that in the toner particle surface modification step, the fine powder component can be removed simultaneously with the toner particle surface modification. As a result, the ultrafine particles present in the toner particles do not adhere to the surface of the toner particles, and toner particles having a desired average circularity, average surface roughness, and ultrafine particle amount can be obtained effectively.

  In the present invention, “removing the fine powder component simultaneously with the surface modification” means that the surface modification of the toner particles and the removal of the fine powder are repeatedly performed. An apparatus having processes may be used, or surface modification and fine powder removal may be performed by different apparatuses, and each process may be repeated.

  A laser beam printer that is one of the electrophotographic image forming apparatuses applied to the present invention will be described below. The laser beam printer receives image information from the host computer and outputs it as a visualized image. The consumables such as an electrophotographic photosensitive member, developing means, and developer can be attached to and detached from the main body of the apparatus as a process cartridge. This is an electrophotographic image forming apparatus.

(About overall configuration of image forming apparatus)
As shown in FIG. 2, the process cartridge 2 is detachable from the image forming apparatus main body 101. When the process cartridge 2 is attached to the main body of the image forming apparatus main body 101, an exposure device (laser scanner unit) 3 for oscillating the laser beam 1 is disposed above the process cartridge 2. A sheet tray 4 containing a recording medium (sheet material) P that is an image forming target is disposed below the process cartridge 2. Further, the image forming apparatus main body 101 includes a pickup roller 5, a paper feed roller (not shown), a transfer roller (not shown), a transfer guide 6, a transfer charging roller 7, along the transport direction of the sheet material P. A conveyance guide 8, a fixing device 9, a paper discharge roller 10, a paper discharge tray 11, and the like are arranged. The fixing device 9 includes a heating roller 9a and a pressure roller 9b.

(About process cartridge configuration)
As shown in FIG. 2 to FIG. 4, the process cartridge 2 integrally includes four types of process devices including a photosensitive drum 20, a charging device 30, a developing device 40, and a cleaning device 50 having a cleaning blade 52. Is housed in. The photosensitive drum 20 and the charging device 30 are attached to a frame 51 of the cleaning device 50. On the other hand, the developing device 40 has coupling arms 48 in the vicinity of both ends thereof as shown in FIG. Note that the photoreceptor rotates in the direction of R1 as shown in FIGS.

  The process cartridge 2 is designed such that when the image forming apparatus main body 101 notifies the user of toner out in the developing device 40, the other process devices also reach the end of their lives at the same time. The user can again output an image having the same performance by taking out the process cartridge out of the toner from the image forming apparatus main body 101 and newly installing a new process cartridge. It can be easily replaced without bothering the user and has excellent usability.

  The developing device 40 is rotatably attached to the frame 51 by means (not shown) at the tip end region of the coupling arm 48. Further, an urging means 60 that is a coil spring is disposed between the developing device 40 and the frame 51, and the developing device 40 is urged clockwise in the drawing.

  Here, an interval holding member (not shown) is attached to both ends of the developing roller 41, and the developing roller 41 is held at a predetermined interval from the photosensitive drum.

(Configuration of developing device)
The magnetic one-component toner T in the toner chamber 45 which is a toner storage chamber is supplied to a toner supply port 45a which is a communication port between the toner chamber 45 and the developing chamber by a toner stirring member 43 having a stirring blade 43a which rotates in the direction of R3. Through the developing chamber 44. The magnetic one-component toner T conveyed to the developing chamber 44 is attracted to the developing sleeve 41 by a magnet roller 41a enclosed and fixed in the developing roller 41, and the developing blade 41 rotates as the developing sleeve 41 rotates in the R2 direction. The toner is transported in the direction of the toner layer thickness regulating member 42, and is fed in the direction of the photosensitive drum 20 by the developing blade 42 after being subjected to frictional charging and layer thickness regulation. The developing blade 42 contacts the developing sleeve 41 at 20 g / cm. A developing bias is applied to the developing sleeve 41 by a developing bias power source 46 by superimposing an AC voltage (peak-to-peak voltage = 1500 Vpp, frequency f = 2400 Hz) on a DC voltage (Vdc = −400 V), and the photosensitive drum 20 is grounded. ing. Since an electric field is generated in a region where the photosensitive drum 20 faces the developing roller 41, the latent image on the surface of the photosensitive drum 20 is developed by the charged magnetic one-component toner T described above.

  Hereinafter, the present invention will be described with reference to specific examples, but the present invention is not limited thereto. Further, “Mn” described in the examples means a number average molecular weight.

  Table 1 shows the physical properties of the binder resin used in this example.

(Toner Production Example 1)
Binder resin 1: 100 parts by mass Wax: 3 parts by mass (low molecular weight polyethylene, DSC endothermic peak temperature = 102 ° C., Mn = 850)
Magnetite (average particle size 0.18 μm) 95 parts by mass Charge control agent (T-77 manufactured by Hodogaya Chemical Co., Ltd.): 2 parts by mass The above mixture was premixed with a Henschel mixer and then heated to 110 ° C. The kneaded material was melt-kneaded with an extruder, and the cooled kneaded material was coarsely pulverized with a hammer mill to obtain a coarsely pulverized toner product. The obtained coarsely pulverized product is finely pulverized using a turbo mill T-250 (manufactured by Turbo Kogyo Co., Ltd.) with an air temperature adjusted to 45 ° C. Fine powder and coarse powder were simultaneously classified and removed by the multi-division classifier (elbow jet classifier manufactured by Nittetsu Mining Co., Ltd.). The weight average particle diameter (D4) measured by the Coulter counter method of the obtained raw material toner particles was 5.9 μm, and the cumulative value of the number average distribution of toner particles of less than 4 μm was 21.1%.

  The raw toner particles were subjected to surface modification and fine powder removal using a surface modification device faculty (manufactured by Hosokawa Micron). At that time, the rotational peripheral speed of the dispersion rotor is 150 m / sec, the input amount of the finely pulverized product is 7.6 kg per cycle, and the surface modification time (= cycle time, the discharge valve opens after the raw material supply is completed) Time) was 82 sec. The temperature when discharging the toner particles was 44 ° C. Through the above steps, negatively chargeable toner particles 1 were obtained. The physical properties of the toner particles 1 are shown in Table 2. Toner 100 was obtained by adding 1.3 parts by mass of hydrophobic silica and 1.0 part by mass of strontium titanate to 100 parts by mass of the toner particles with a Henschel mixer. Table 2 shows the physical properties of this toner 1 and the values of E, E-Ea, and Ed / E measured by FT-4. In addition, the cumulative value of the number average distribution of the toner 1 having a weight average particle diameter (D4) of 5.9 μm and less than 4 μm was 19.3%.

(Toner Production Example 2)
The cumulative value of the number average distribution of the toner particles having a weight average particle diameter (D4) of the raw material toner particles of 5.5 μm and less than 4 μm is set to 25.4%, and the input amount per cycle of the surface reformer is 8.5 kg. A toner particle 2 was obtained in the same manner as the toner particle 1 except that. Table 2 shows the physical properties of Toner Particles 2. Toner 2 was obtained by externally mixing 100 parts by mass of toner particles 2 with 1.0 part by mass of hydrophobic silica and 0.8 parts by mass of strontium titanate using a Henschel mixer. Table 2 shows the physical properties of this toner 2 and the values of E, E-Ea, and Ed / E measured by FT-4. The weight average particle diameter (D4) of the toner 2 is 5.3 μm, and the cumulative value of the number average distribution of toners less than 4 μm is 21.2%.

(Toner Production Example 3)
Toner particles 3 were obtained in the same manner as toner particles 1 except that binder resin 2 was used in place of binder resin 1 and the temperature at the time of toner particle discharge from the surface modification device was set to 35 ° C. Table 2 shows the physical properties of the toner particles 3. Toner 3 was obtained by externally mixing 100 parts by mass of the toner particles 3 with 1.3 parts by mass of hydrophobic silica and 1.0 part by mass of strontium titanate using a Henschel mixer. Table 2 shows the physical properties of this toner 3 and the values of E, E-Ea, and Ed / E measured by FT-4. The weight average particle diameter (D4) of the toner 3 was 5.8 μm, and the cumulative value of the number average distribution of toners less than 4 μm was 18.4%.

(Toner Production Example 4)
The binder resin 2 is used instead of the binder resin 1, the weight average particle diameter (D4) of the raw toner particles is 6.8 μm, the cumulative value of the number average distribution of toner particles less than 4 μm is 46.3%, Toner particles 4 were obtained in the same manner as toner particles 1 except that the rotating peripheral speed of the dispersing rotor of the reformer was 140 m / sec and the temperature at which the toner particles were discharged was 38 ° C. Table 2 shows the physical properties of the toner particles 4. Toner 4 was obtained by adding 1.45 parts by mass of hydrophobic silica and 1.2 parts by mass of strontium titanate to 100 parts by mass of the toner particles by a Henschel mixer. Table 2 shows the physical properties of this toner 4 and the values of E, E-Ea, and Ed / E measured by FT-4. The weight average particle diameter (D4) of the toner 4 was 6.8 μm, and the cumulative value of the number average distribution of toners less than 4 μm was 17.0%.

(Toner Production Example 5)
Toner particles 1 except that the weight average particle diameter (D4) of the raw material toner particles is 6.8 μm, the cumulative value of the number average distribution of toner particles less than 4 μm is 49.0%, and no treatment is performed in the surface reforming apparatus. In the same manner, toner particles 5 were obtained. Table 2 shows the physical properties of the toner particles 5. Toner 5 was obtained by adding 1.5 parts by mass of hydrophobic silica and 1.0 part by mass of strontium titanate to 100 parts by mass of the toner particles with a Henschel mixer. Table 2 shows the physical properties of this toner 5 and the values of E, E-Ea, and Ed / E measured by FT-4. The weight average particle diameter (D4) of the toner 5 is 6.6 μm, and the cumulative value of the number average distribution of toner particles of less than 4 μm is 28.1%.

(Toner Production Example 6)
The binder resin 2 is used in place of the binder resin 1, and finely pulverized using a jet airflow pulverizer IDS type mill (manufactured by Nippon Pneumatic Industry Co., Ltd.) without using a mechanical pulverizer, and the weight of the raw toner particles The cumulative value of the number average distribution of toner particles having an average particle diameter (D4) of 5.7 μm and less than 4 μm is set to 41.6%, and the same method as that for the toner particles 1 is used except that the treatment with the surface modifying apparatus is not performed. Toner particles 6 were obtained. Table 2 shows the physical properties of the toner particles 6. Toner 6 was obtained by adding 1.5 parts by weight of hydrophobic silica and 0.8 parts by weight of strontium titanate to 100 parts by weight of the toner particles by a Henschel mixer. Table 2 shows the physical properties of this toner 6 and the values of E, E-Ea, and Ed / E measured by FT-4. The cumulative value of the number average distribution of toner particles having a weight average particle diameter (D4) of the toner 6 of 5.8 μm and less than 4 μm was 30.1%.

(Toner Production Example 7)
The binder resin 2 was used in place of the binder resin 1, and the cumulative value of the number average distribution of the toner particles having a weight average particle diameter (D4) of the raw toner particles of 8.9 μm and less than 4 μm was set to 30.3%. Obtained toner particles 7 in the same manner as toner particles 1. Table 2 shows the physical properties of the toner particles 7. Toner 7 was obtained by adding 1.0 part by mass of hydrophobic silica and 1.5 parts by mass of strontium titanate to 100 parts by mass of the toner particles by a Henschel mixer. Table 2 shows the physical properties of the toner 7 and the values of E, E-Ea, and Ed / E measured by FT-4. The cumulative value of the number average distribution of toner particles having a weight average particle diameter (D4) of the toner 7 of 9.0 μm and less than 4 μm was 28.7%.

<Measurement of average circularity of toner particles>
The average circularity of the toner particles was measured with a flow type particle image analyzer “FPIA-3000 type” (manufactured by Sysmex Corporation) under the measurement and analysis conditions during the calibration operation.

  As a specific measurement method, a suitable amount of a surfactant, preferably an alkylbenzene sulfonate, is added to 20 ml of ion-exchanged water, and then 0.06 g of a measurement sample is added, and an oscillation frequency of 50 kHz and an electric output of 150 W is added. Dispersion treatment was carried out for 2 minutes using a desktop type ultrasonic cleaner / disperser (for example, “VS-150” (manufactured by VervoCrea Co., Ltd.)) to obtain a dispersion for measurement. It cools suitably so that it may become 10 to 40 degreeC.

  For the measurement, the flow type particle image analyzer equipped with a high-magnification imaging unit (objective lens (20 ×)) was used, and the particle sheath “PSE-900A” (manufactured by Sysmex Corporation) was used as the sheath liquid. The dispersion prepared in accordance with the above procedure is introduced into the flow type particle image analyzer, and 2000 toner particles are measured in the total count mode in the HPF measurement mode, and the binarization threshold at the time of particle analysis is 85%. It was. The analysis particle diameter was limited to the equivalent circle diameter of 1.98 μm or more and less than 30.0 μm, or the equivalent circle diameter of 0.25 μm or more and less than 30.0 μm, and the average circularity and the ratio of ultrafine powder were calculated.

  In measurement, automatic focus adjustment is performed using standard latex particles (for example, Duke Scientific 5100A diluted with ion-exchanged water) before the start of measurement. Thereafter, it is preferable to perform focus adjustment every two hours from the start of measurement.

  In the examples of the present application, a calibration work by Sysmex Corporation was performed, a flow type particle image analyzer that received a calibration certificate issued by Sysmex Corporation was used, except that the analysis particle diameter was limited. The measurement was performed under the measurement and analysis conditions when the calibration certificate was received.

[Examples 1-7, Comparative Examples 1-4]
Next, evaluation was performed using the toners 1 to 7 prepared as described above by the following method. Table 3 shows the used toner and the configuration of the toner circulation guide member. The evaluation results are shown in Table 4.

(Evaluation of image density and image streaks)
A commercially available LBP printer (Laser Jet 4350n, manufactured by HP) was modified to obtain A4 size 65 sheets / min. The developer was modified so that the capacity of the toner container of the process cartridge was 1.2 times. Further, the stirring blade was stretched 1.2 times in the rotation direction, and 1300 g of toner was charged.

  Using this as an imaging tester, after leaving overnight in a high-temperature and high-humidity environment of 32.5 ° C. and 85% RH, a horizontal line pattern with a printing rate of 2% is taken as one sheet / job, and between jobs. A print durability test of 20,000 sheets was performed using A4 plain paper (75 g / m 2) in a mode in which the machine was temporarily stopped and the next job was started.

  The following evaluation was performed during this print durability test or after a durability test of 20,000 sheets.

  The image density was measured and evaluated by measuring the reflection density of a 5 mm square solid black image using an SPI filter with a Macbeth densitometer (Macbeth Co., Ltd.), which is a reflection densitometer.

The image density was measured by measuring the reflection density of a solid black image of 5 mm square using an SPI filter with a Macbeth densitometer (Macbeth Co.) which is a reflection densitometer. The evaluation results are shown in Table 4. In addition, the evaluation criteria of the image density at this time are shown below.
A: The reduction rate of the reflection density before and after durability is less than 2%.
B: The decrease rate of the reflection density before and after durability is 2% or more and less than 4%.
C: The reduction rate of the reflection density before and after durability is 4% or more and less than 8%.
D: The reduction rate of the reflection density before and after durability is 8% or more.

The evaluation criteria for image streaks are shown below.
A: No streak is generated even after 20,000 sheets.
B: Streaks occur in halftone up to 20,000 sheets.
C: Solid black streaks occur up to 20,000 sheets.
D: Streaks occur up to 5000 sheets.

(Evaluation of fading)
After the image density evaluation, 10 halftone patterns with a printing rate of 25% were output, and the occurrence of fading was confirmed. As a result, even when a halftone image having a high printing rate was output, fading did not occur and an image without unevenness was obtained. The evaluation results are shown in Table 4. The fading evaluation criteria at this time are shown below.
A: No occurrence.
B: There is a slightly thin part.
C: The density is clearly reduced in a band shape.

(Evaluation of rise of image density)
Under normal temperature and humidity conditions (23 ° C, 50% RH), set the toner filling amount to 200 g, 2 sheets / 1 job, and the machine will stop once between jobs before the next job starts. In this mode, 200 sheets were endured, and the density variation was evaluated as a difference between the first sheet and the 200th sheet. The evaluation results are shown in Table 4. The evaluation criteria for the image density variation at this time are shown below.
A: Density difference less than 0.02 There is no rise in density.
B: Density difference 0.02 or more and less than 0.05 The density rises.
C: Density difference of 0.05 or more There is a rise in density.

(Evaluation of sleeve ghost and fog)
The same testing machine used for image density and image streaking was left overnight in a low-temperature and low-humidity environment at 15 ° C and 10% RH, and then a horizontal line pattern with a printing rate of 3% was printed per sheet / job. In a mode in which the machine is temporarily stopped between jobs and the next job starts, a print durability test of 15,000 sheets using A4 plain paper (90 g / m ² ) went. Sleeve ghost and fog were evaluated every 500 sheets from the beginning of the durability, and the evaluation was based on the worst image among them. The evaluation results are shown in Table 4. The evaluation criteria for sleeve ghost at this time are shown below. The sleeve ghost was evaluated by the difference between the image density of the first round of the sleeve on the top of the solid black image and the image density after the second week.

Evaluation of sleeve ghost A: 0 ≦ | (image density at the first round of the sleeve) − (image density after the second week of the sleeve) | ≦ 0.02
B: 0.02 <| (image density in the first round of the sleeve) − (image density after the second week of the sleeve) | ≦ 0.04
C: 0.04 <| (Image density of the first round of the sleeve) − (Image density of the second and subsequent weeks of the sleeve) | ≦ 0.06
D: 0.06 <| (image density in the first round of the sleeve) − (image density in the second and subsequent weeks of the sleeve) |
The evaluation criteria for fogging are shown below.
A: Fog amount less than 1.0% B: Fog amount less than 2.0% C: Fog amount less than 3.0% D: Fog amount less than 4.0% E: Fog amount 4.1% or more

It is a schematic diagram of a partial cross section of an example of a developing device used in the present invention. It is a schematic diagram of a partial cross-sectional view of an example of an image forming apparatus used in the present invention. It is a schematic diagram of the longitudinal cross-sectional view of an example of the process cartridge of this invention. It is a schematic diagram of the longitudinal cross-sectional view of an example of the image development apparatus used for this invention. It is explanatory drawing of the external appearance (a) of the propeller-type blade of a powder fluidity | liquidity analyzer, and the twist angle (b) of a blade outermost edge part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Toner circulation guide member 2 Process cartridge 3 Laser scanner unit 4 Sheet tray 5 Pickup roller 6 Transfer guide 7 Transfer charging roller 8 Conveyance guide 9 Fixing device 9a Heating roller 9b Pressure roller 10 Paper discharge roller 11 Paper discharge tray 20 Photosensitive drum 30 Charging device 40 Developing device 41 Developing sleeve 41a Magnet roller 42 Toner layer thickness regulating member (developing blade)
43 toner stirring member 43a stirring blade 44 developing chamber 45 toner chamber 45a toner supply port 46 developing bias power supply 48 coupling arm 50 cleaning device 51 frame 52 cleaning blade 60 coil spring 101 image forming apparatus main body L laser beam P recording medium T magnetic one component Toner M1 to M9 Toner circulation direction R2 Development sleeve rotation direction N1, N2, S1, S2 Magnetic pole of magnet roller E2 Space

Claims (5)

At least a stirring step of stirring the toner by a stirring member;
A conveying step of carrying the toner on a toner carrier;
A toner layer thickness regulating step of regulating the layer thickness of the toner on the toner carrier by a toner layer thickness regulating member;
The toner has an upper end and a lower end on the upper side of the toner layer thickness regulating member on the side where the toner is taken in, is not in contact with the toner layer thickness regulating member, and extends from the upper end to the lower end. A toner used in an image forming method having a circulation step of circulating by a toner circulation guide member having a length of 3 mm or more,
The toner has toner particles containing at least a binder resin and a colorant, and inorganic fine particles, and has the following formulas (1) and (2):
600 (mJ) ≦ E ≦ 1500 (mJ) (1)
500 (mJ) ≦ (E−Ea) (2)
(In the formulas (1) and (2), E (mJ) vertically enters the toner powder layer in the container while rotating the peripheral speed of the outermost edge of the propeller blade at 100 mm / sec. The measurement starts from a position 100 mm from the bottom surface of the toner powder layer, and represents the sum of the rotational torque and the vertical load obtained when the toner powder is moved to a position 10 mm from the bottom surface. Ea is a porous plate at the bottom of the container. It represents the sum of the rotational torque and the vertical load in the ventilation state in which dry air with a flow rate of 0.20 mm / s is sent from there.)
A toner characterized by satisfying The toner has the following formula (3)
0.10 <(Ed / E) <0.70 (3)
(In the formula (3), Ed (mJ) sends dry air whose flow rate is controlled to the powder phase of the toner in the container, and stops the ventilation when E becomes 30 (mJ) or less. Then, the same measurement as the above E is repeated four times, and represents the total of the rotational torque and the vertical load obtained by the fourth measurement.)
The toner according to claim 1, wherein: The toner circulation guide member has an upper end of −15 ° to 15 ° with respect to the rotation direction of the toner carrier with respect to a straight line A connecting the rotation center of the toner carrier and the end of the toner layer thickness regulating member. The lower end is present between −30 ° and 0 °,
The shortest distance between the toner circulation guide member and the toner carrier is 1 mm or more and 7 mm or less,
The inclination of the straight line B with respect to the straight line A when it is centered on the intersection of the straight line B connecting the upper end and the lower end is 0 ° or more and 35 ° or less on the toner carrier side, and is far from the toner carrier. The toner according to claim 1, wherein the toner is in a range of 0 ° to 45 ° in a direction. At least a stirring step of stirring the toner by a stirring member;
A conveying step of carrying the toner on a toner carrier;
A toner layer thickness regulating step of regulating the layer thickness of the toner on the toner carrier by a toner layer thickness regulating member;
The toner has an upper end and a lower end on the upper side of the toner layer thickness regulating member on the side where the toner is taken in, is not in contact with the toner layer thickness regulating member, and extends from the upper end to the lower end. An image forming method including a circulation step of circulating by a toner circulation guide member having a length of 3 mm or more,
The toner has toner particles containing at least a binder resin and a colorant, and inorganic fine particles, and has the following formulas (1) and (2):
600 (mJ) ≦ E ≦ 1500 (mJ) (1)
500 (mJ) ≦ (E−Ea) (2)
(In the formulas (1) and (2), E (mJ) vertically enters the toner powder layer in the container while rotating the peripheral speed of the outermost edge of the propeller blade at 100 mm / sec. The measurement starts from a position 100 mm from the bottom surface of the toner powder layer, and represents the sum of the rotational torque and the vertical load obtained when the toner powder is moved to a position 10 mm from the bottom surface. Ea is a porous plate at the bottom of the container. It represents the sum of the rotational torque and the vertical load in the ventilation state in which dry air with a flow rate of 0.20 mm / s is sent from there.)
An image forming method characterized by satisfying At least a stirring member for stirring the toner;
A rotatable toner carrier for carrying and transporting the toner;
A toner layer thickness regulating member for regulating the layer thickness of the toner on the toner carrier;
A process cartridge having a toner circulation guide member having an upper end and a lower end in a non-contact manner on an upper end of the toner layer thickness regulating member on the side of taking in the toner;
The toner has toner particles containing at least a binder resin and a colorant, and inorganic fine particles, and has the following formulas (1) and (2):
600 (mJ) ≦ E ≦ 1500 (mJ) (1)
500 (mJ) ≦ (E−Ea) (2)
(In the formulas (1) and (2), E (mJ) vertically enters the toner powder layer in the container while rotating the peripheral speed of the outermost edge of the propeller blade at 100 mm / sec. The measurement starts from a position 100 mm from the bottom surface of the toner powder layer, and represents the sum of the rotational torque and the vertical load obtained when the toner powder is moved to a position 10 mm from the bottom surface. Ea is a porous plate at the bottom of the container. It represents the sum of the rotational torque and the vertical load in the ventilation state in which dry air with a flow rate of 0.20 mm / s is sent from there.)
A process cartridge characterized by satisfying

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