JP4855309B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a copying machine or a printer. More specifically, the present invention relates to an image carrier (hereinafter also referred to as a member to be charged), a charging unit, a developing unit, a transfer unit, a cleaning unit, and a lubricant. The present invention relates to an image forming apparatus that includes at least a coating unit and a lubricant, and further uses a specific toner.

  In the conventional image forming apparatus, as shown in FIG. 1, the image forming area on the surface of the image carrier (8) is uniformly charged by the charging means (1), and the image carrier (1) is exposed by the exposure means (2). Then, an image is formed by toner triboelectrically charged on the image carrier 8 by the developing means (3). Subsequently, the toner image on the image carrier (8) is transferred directly to the printing paper conveyed from the paper feeding means (9) by the transfer means (4) or indirectly to the printing paper through the intermediate transfer member. Thereafter, the image is fixed on the printing paper by the fixing means (10). On the other hand, the untransferred toner remaining on the image carrier 8 without being transferred is scraped off from the image carrier (8) by the cleaning means (7). The image carrier (8) is formed in a cylindrical shape or a belt shape, and after going through a series of these image forming processes, it enters the next image forming process as it is.

  An image forming apparatus comprising such a process has a revolver system that has only one image carrier and forms an image for each color with the image carrier, and a tandem system that uses one image carrier for each color. In the revolver method, the cost is low, and in the tandem method, the cost is high, but high-speed printing can be performed. The current mainstream is the tandem method that enables high-speed printing.

  Here, the charging means (1), the exposure means (2), the developing means (3), the transfer means (4), the cleaning means (7), etc., and the toner, lubricant and lubricant application means used in these means The following is a description of the above.

(Charging means)
Examples of the charging means (1) include DC, a proximity charging system in which AC is superimposed on DC, a contact charging system, and a corona charging system. Examples of the corona charging method include a corotron charger and a scorotron charger.
Conventionally, corotron chargers utilizing corona discharge, scorotron chargers and the like have been mainstream as charging means for charging an image carrier. However, the charging means using the corona discharge has a problem that a large amount of ozone is generated or NOx generated by the corona discharge adheres to the image carrier and causes a problem such as image flow over time. There was a point. In addition, since a high voltage power source that applies a high voltage of 5 to 10 kV is required to perform corona discharge, it is difficult to reduce the cost of the image forming apparatus.
Therefore, in recent years, as a charging unit that can be employed in an image forming apparatus, a contact type charging unit that does not use corona discharge, a charging unit that contacts the image carrier, or a proximity type that closes the charging unit to the image carrier. Many charging means have been proposed. In this contact type / proximity type charging means, many of the problems mentioned in the case of the charging means using the corona discharge are solved, but the wear amount of the image carrier increases and the life is shortened. There is also a problem. In addition, when alternating current is used as the applied voltage, noise is also a problem. In addition, since the charging unit rubs toner or paper dust against the image carrier, the surface of the image carrier is promoted to be contaminated, and a problem due to contamination of the surface of the charging unit has also occurred. Therefore, an AC voltage superposition charging method in which a voltage obtained by superimposing an alternating current voltage on a direct current voltage is applied to a charging member to charge the photosensitive member is attracting attention.

(Exposure means)
Examples of the exposure means (2) include an exposure method using an LD, an LED lamp, and a xenon lamp.

(Development means)
Examples of the developing means include a one-component developing means and a developing method using a two-component developing means for mixing and developing toner and a carrier.
As the developer, there are a two-component developer composed of a toner and a carrier and a one-component developer composed of only a magnetic or non-magnetic toner. The production of these toners is generally a kneading and pulverization method in which a resin, pigment, charge control agent, and release agent are melt-kneaded, cooled and then pulverized and classified, but the particle size and shape are not uniform, and these are controlled. It is difficult to do.
Under such circumstances, recently, there has been an attempt to control the particle size of toner particles intentionally to solve the above-mentioned problems, and polymerized toner methods such as emulsion polymerization method and dissolution suspension method as aqueous granulation. Became popular.
In recent years, there has been an increasing demand for higher image quality, and in particular, in order to realize high-definition images in color image formation, there has also been an increasing demand for toner diameter reduction and particle size uniformity. When an image is formed using toner having a wide particle size distribution, the fine powder toner contaminates the developing sleeve, the contact / proximity charging means, the cleaning blade, the image carrier (photoconductor), the carrier, etc., or the toner scatters. It has become difficult to achieve high image quality and high reliability at the same time.
On the other hand, when the particle size is uniform and the particle size distribution is sharp, the development behavior of the individual toner particles is uniform, and the reproducibility of minute dots is greatly improved. However, a toner having a small particle size and a uniform particle size has a problem with respect to cleaning properties. In particular, it is impossible to stably clean a toner having a uniform and small particle diameter by blade cleaning. In view of this, various methods have been proposed for improving the cleaning property by devising the toner. One of them is a method in which the toner is deformed from a spherical shape to cope with it. By changing the shape of the toner, the powder fluidity of the toner is lowered and it is easy to dam by blade cleaning. However, if the degree of toner deformation is excessively large, the behavior of the toner becomes unstable during development and the like, and the fine dot reproducibility deteriorates. As described above, characteristics such as toner transfer quality, transfer efficiency, and cleaning performance are affected by the toner shape. Therefore, in order to obtain a toner having the above characteristics, an optimum design of the toner shape distribution is required.

(Transfer means)
Examples of the transfer means (4) include a transfer method using a transfer belt, a transfer charger, and a transfer roller.

(Cleaning means)
Examples of the cleaning means (7) include a blade-shaped cleaning blade made of polyurethane rubber, silicone rubber, nitrile rubber, chloroprene rubber, or the like, or a fur brush, an elastic roller, a tube-covered roller, and a nonwoven fabric.
Conventionally, the cleaning method of an image forming apparatus in the electrophotographic method is mainly a cleaning method using a blade, and there are a large number of image forming apparatuses having cleaning means only for the blade. Some high-speed machines are provided with cleaning assisting means in order to avoid a state in which a large amount of toner is partially attached. At this time, when a cleaning blade is used as the cleaning means, the image carrier is brought into contact with a trailing or counter.
If the cleaning of the toner on the image carrier is insufficient with only the cleaning means, a means for improving the cleaning property is provided by installing a cleaning auxiliary means on the downstream side in the rotation direction of the image carrier and upstream of the cleaning means. I came. Examples of the cleaning auxiliary means include a fur brush, an elastic roller, a tube covering roller, and a nonwoven fabric.
The conventional cleaning auxiliary means is installed on the upstream side of the cleaning means, and the above-described one has been used. This is intended to mechanically disturb the toner input to the cleaning means and improve the cleaning performance of the cleaning means. At this time, an image forming apparatus in which a voltage is applied to the cleaning auxiliary means and the polarity of the toner is controlled to improve the cleaning property has been put on the market.

  Further, in the image forming apparatus as described above, the water-based granulated toner is desired to be used for obtaining a higher quality image, but it is difficult to ensure the cleaning property. Therefore, in the case of using a toner having a high sphericity, the margin of cleaning performance is improved, the image carrier wear due to discharge in the charging means, the image carrier wear due to the contact of the cleaning means or toner, and the image carrier filming. In order to prevent this, the image carrier is often provided with a means for applying a lubricant.

(Water-based granulated toner)
Regarding the production of water-based granulated toner, Patent Document 1 and the like describe a technique for producing a spherical toner in a wet manner by a suspension polymerization method or an emulsion polymerization method, and Patent Document 2 and Patent Document 3 and the like treat a pulverized toner by heat treatment. Thus, a technique for making the particles spherical has been proposed, and according to such a toner manufacturing method, it is easy to reduce the particle size of the toner.

(Lubricant application means)
In order to increase the life and image quality of an image carrier, a lubricant is applied on the image carrier. The purpose of applying the lubricant is as follows. (I) The occurrence of toner filming (fusion) is prevented. (Ii) By reducing the friction coefficient, the transfer efficiency can be improved and the cleaning failure can be prevented. For these problems, for example, techniques described in Patent Document 4, Patent Document 5, Patent Document 6, Patent Document 7, and the like are known, and a lubricant (5) is placed on an image carrier (8). It is solved by applying. In these examples, the problem is solved by applying the lubricant (5) on the image carrier (8) and reducing the coefficient of friction in any case.

The lubricant applying means may be a method of applying to the image carrier using a fur brush, loop brush, roller, or belt, or a method of applying solid lubricant or lubricant powder directly to the image carrier.
As another method for applying the lubricant to the image carrier, a technique in which the lubricant is externally added to the toner and the lubricant is applied to the image carrier together with the toner supply is also known. In the non-supplied region (non-image region), the lubricant was not applied to the image carrier, and the image carrier wear due to discharge and the image carrier wear due to the contact member could not be prevented.
Also known is a method in which a solid lubricant is brought into direct contact with the cleaning auxiliary means, and the lubricant is applied to the image carrier. In this method, in the region where there is residual transfer toner (image region), the lubricant is It was not applied to the image carrier, and it was impossible to prevent image carrier wear due to discharge and image carrier wear due to the contact member.

  In order to solve these problems, the lubricant powder is brought into direct contact with the image carrier downstream of the image carrier rotation direction cleaning means, and the lubricant is further distributed downstream of the image carrier rotation direction and upstream of the charging means. A method of applying a lubricant to the entire surface of the image carrier by providing a blade has also been devised. Further, as means for measuring the same uniform application of the lubricant, the lubricant is pressed against the lubricant application means in the rotation direction of the image carrier and downstream of the cleaning means, and the lubricant is applied to the image carrier by the lubricant application means. There has also been devised a method of applying a lubricant to the entire surface of the image carrier by applying the lubricant and providing a lubricant leveling blade on the downstream side in the rotation direction of the image carrier and upstream of the charging means. By these methods, the lubricant can be applied to the entire surface of the image carrier, and the entire surface of the image carrier can be protected from the wear of the image carrier due to the discharge by the charging means and the wear of the image carrier by the contact member. .

In order to extend the life of the charging means and the image carrier, non-contact charging means is used, inorganic fine particles are dispersed in the photosensitive layer of the image carrier, and zinc stearate or the like is applied as a lubricant. As an example in which the wear resistance is improved, there is a technique described in Patent Document 8. In addition, an image forming apparatus having a blade-like auxiliary member for adhering the lubricant applied to the surface of the image carrier thinly and uniformly between the charging means and the developing means, and clogging the lubricant having a large diameter As an example of this, the one described in Patent Document 9 is known.
On the other hand, in general, the contact charging method and the proximity charging method have a smaller amount of discharge products than the corona charging method, and can be charged with low power. However, in these charging methods, the photosensitive member and the charging member are in contact with each other, or the distance between the photosensitive member and the charging member is shorter than the distance between the photosensitive member and the charge wire. It is clear that it is larger than the method. In particular, when an AC voltage is superimposed, the hazard increases because the discharge is repeated according to the frequency of the AC voltage. As a result, chemical deterioration of the surface of the photoconductor progresses, and eventually the film is scraped on the surface of the photoconductor. Will occur. When lubricant is applied to the surface of the photoreceptor, the molecular structure or surface energy of the lubricant is changed and the lubricity is lost. The lubricant is gradually scraped and eventually disappears. Etc. also have problems.

(Amount of lubricant applied)
In view of these conventional techniques, in an image forming apparatus employing a contact charging method or a proximity charging method, the amount of lubricant applied to the surface of the photoconductor is set to an amount capable of suppressing deterioration of the surface of the photoconductor, and the image carrier is lubricated. As an application amount of the agent (hereinafter also referred to as a lubricating substance), Patent Document 10 proposes an optimal application amount as follows.
That is, the ratio of the number of elements of the specific element of the lubricating material detected by the XPS to the total number of elements of all elements of the material constituting the outermost surface of the charged body detected by an X-ray photoelectron spectrometer (XPS) Let A [%] be equal to or greater than the following [Equation 1].
[Equation 1]
1.52 × 10 ⁻⁴ × {Vpp−2 × Vth} × f / v × Nα
(Where Vpp is the peak-to-peak voltage value [unit: V] of the AC voltage, f is the frequency of the AC component applied to the charging means 1 [unit: Hz], and v is the moving speed of the surface of the object to be charged [unit: V]. mm / sec], Nα is the number of elements in one molecule of a specific element among the elements constituting the lubricant, and Vth is the discharge start voltage, which is obtained by the following [Equation 2].
[Equation 2]
Vth = 312 + 6.2 × (d / εopc + Gp / εair) + √ (7737.6 × d / εopc)
(At this time, d is the film thickness [unit: μm] of the member to be charged, εopc is the relative dielectric constant of the member to be charged, εair is the relative dielectric constant in the space between the member to be charged and the charging means (1), and Gp is Charging means (1) The closest distance [unit: μm] between the surface and the surface of the object to be charged.)
Further, the ratio A [%] of the number of elements constituting the lubricating material detected by the XPS with respect to the total number of elements of all the elements constituting the material to be charged detected by the XPS is expressed as follows: [Equation 3] It is set to the formula or more.
[Equation 3]
1.52 × 10 ⁻⁴ × {Vpp−2 × Vth} × f / v × Nβ
(Here, Nβ: a value obtained by subtracting the number of hydrogen elements from the total number of elements constituting one molecule of the lubricating substance.)

  According to the invention relating to the amount of applied lubricant, the lubricant can be uniformly applied to the entire surface of the image carrier, and the wear of the image carrier due to discharge by the charging means can be reduced, and the life of the image carrier can be extended. However, as a result of studies by the present inventors, it has been found that the conventional technique using the lubricant application technique is insufficient to output high image quality over a long period of time. Specifically, by using the lubricant application technique, it was possible to prevent image carrier wear due to discharge by the charging means, but when a cleaning blade was used as the cleaning means, the edge was worn early, Image quality deterioration occurs due to poor cleaning of the image carrier surface. On the other hand, an abnormal image that is different from a cleaning failure, specifically, an image flow occurs. The reason is considered to be as follows.

According to previous studies, lubricant was applied to the image carrier with the aim of reducing the friction coefficient on the surface of the image carrier, but the charging means used a charging means that uses proximity or direct discharge. The lubricant applied to the surface of the image carrier is decomposed, the molecular chain becomes shorter and the lubricant deteriorates, so that the coefficient of friction on the surface of the image carrier is actually larger than when no lubricant is applied. Turned out to be. Further, in this case, the surface state of the image carrier is not uniform, and the friction coefficient distribution on the surface of the image carrier becomes large.
That is, in the image forming apparatus using the proximity or contact charging method, by applying the lubricant, the coefficient of friction on the surface of the image carrier increases on average, and the distribution also increases. For this reason, when the cleaning blade is used as the cleaning means, the amount of the cleaning blade edge involved becomes larger than that when the lubricant is not normally applied, and the deterioration is promoted.
Further, the distribution of the coefficient of friction on the surface of the image carrier is increased, so that the stick slip of the cleaning blade edge is increased and the wear is further promoted.
For this reason, it is thought that the image defect by the cleaning blade edge wear as described above occurs. Regarding the occurrence of image flow, the lubricant on the surface of the image carrier is deteriorated by receiving electric discharge, so that the surface property (wetting property) is increased. For this reason, it is considered that the moisture tends to be adsorbed on the surface of the image carrier, the resistance of the surface of the image carrier is lowered, the charge transfer after the latent image is written, and the image flow phenomenon occurs.
For these reasons, cleaning blade edge wear is reduced, image carrier wear is also reduced, and in order to obtain high image quality over a long period of time without generating more images than the image flow, always remove the deteriorated lubricant. It is necessary to continue.

JP-A-1-257857 Japanese Patent Publication No. 4-27897 JP-A-6-317928 JP 2002-244516 A JP 2002-156877 A JP 2002-55580 A JP 2002-244487 A JP 2002-229227 A Japanese Patent Laid-Open No. 10-142897 JP 2005-17469 A

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to remove the above-described deteriorated lubricant during image formation, and as a result, on the image carrier. An object of the present invention is to provide an image forming apparatus in which no deteriorated lubricant is present and a stable high quality image can be obtained at all times. Another object of the present invention is to provide an image forming apparatus capable of stably using an image carrier for a long period of time.

As a result of many studies and studies to achieve the above object, the present inventors have found that the above-described deteriorated lubricant is removed during image formation by using a specific toner. I found it. That is, according to the present invention, by using a specific toner, the area for adsorbing the lubricant on the toner surface is increased, the lubricant deteriorated by the toner is removed from the surface of the image carrier, and the cleaning blade is worn and the image flow image is removed. It is intended to prevent the occurrence of.
Therefore, it is necessary to increase the BET specific surface area of the toner in order to remove the deteriorated lubricant after applying the necessary lubricant on the surface of the image carrier. However, the toner in the present invention is a toner granulated in water system. Even so, the BET specific surface area of the toner can be increased by including in the toner at least a binder resin, a colorant, and a modified layered inorganic mineral in which at least some of the ions between layers are modified with organic ions. be able to.
Further, by adding inorganic fine particles to the toner base and producing the toner so that the BET specific surface area is 2.5 to 7.0 (m ² / g), the toner can be used within a range where there is no problem in other systems. In addition, a lubricant removing function can be provided while providing a necessary function.

That is, said subject is solved by invention of following (1)-(11).
(1) an image carrier, a charging unit for charging the surface of the image carrier by proximity or direct discharge, an exposure unit for writing a latent image by exposing the image carrier, and a latent image written on the image carrier. In an image forming apparatus comprising: a developing unit that develops an image with toner; and a transfer unit that transfers the developed toner to an intermediate transfer member or printing paper.
The amount of lubricant applied to the image carrier is in the range represented by the following formulas 1 to 3,
Ratio of the number of elements A of the specific element of the lubricant detected by the XPS to the total number of elements of the elements constituting the outermost surface of the image carrier detected by the X-ray photoelectron spectrometer (XPS) A ( %) Satisfies the following number 1,
[Equation 1]
A ≧ 1.52 × 10 ⁻⁴ × {Vpp−2 × Vth} × f / v × Nα
(Where Vpp is the AC voltage peak-to-peak voltage value [unit: V],
f is the frequency [unit: Hz] of the AC component applied to the charging means 1;
v is the moving speed of the surface of the member to be charged [unit: mm / sec],
Nα is the number of elements in one molecule of a specific element among the elements constituting the lubricating material.
Vth is a discharge start voltage, and is obtained by the following equation (2). )
[Equation 2]
Vth = 312 + 6.2 × (d / εopc + Gp / εair) + √ (7737.6 × d / εopc)
(At this time, d is the film thickness of the member to be charged [unit: μm],
εopc is the dielectric constant of the object to be charged,
εair is the relative dielectric constant in the space between the object to be charged and the charging means (1),
Gp is the closest distance [unit: μm] between the surface of the charging means (1) and the surface of the member to be charged. )
The ratio B (%) of the number of elements constituting the lubricating material detected by XPS with respect to the total number of elements of all the elements constituting the outermost surface of the image carrier detected by XPS is as follows: Satisfy 3
[Equation 3]
B ≧ 1.52 × 10 ⁻⁴ × {Vpp−2 × Vth} × f / v × Nβ
(Here, Nβ: a value obtained by subtracting the number of hydrogen elements from the total number of elements constituting one molecule of the lubricating substance.)
(The lubricating material is a fatty acid metal salt, the specific element is a metal, Nα is 1, and Nβ is 41. The closest distance between the charging means and the image carrier is 1 to 100 [ μm])
The toner used for developing the image bearing member by the developing means is an aqueous granulated toner, and at least a binder resin, a colorant, and at least a part of ions between layers are modified with organic ions. A toner containing a modified layered inorganic mineral and having a BET specific surface area of 2.5 to 7.0 (m ² / g),
An image forming apparatus characterized by that.
(2) The image forming apparatus according to (1), wherein the modified layered inorganic mineral is obtained by modifying at least a part of a metal cation with an organic cation.
(3) The toner may have a ratio (Dv / Dn) of a volume average particle diameter (Dv) to a number average particle diameter (Dn) in a range of 1.00 to 1.40. Or the image forming apparatus according to (2).
(4) The image forming apparatus according to (1) or (2), wherein the toner has 1 to 10% by number of particles of 2 μm or less.
(5) The image forming apparatus according to (1) or (2), wherein the toner is prepared by externally adding a plurality of inorganic fine particles.
(6) The image forming apparatus according to (5), wherein the inorganic fine particles include at least silica and titanium.
(7) The image forming apparatus according to (1) or (2), wherein a cleaning unit is provided in the rotation direction of the image carrier and a lubricant application unit is provided on the downstream side.
(8) A cleaning means is provided in the rotational direction of the image carrier, and a lubricant application means is provided on the downstream side, and a lubricant leveling means is provided on the downstream side of the lubricant application means and on the upstream side of the charging means. The image forming apparatus according to (1) or (2), wherein the image forming apparatus is characterized.
(9) The image forming apparatus according to any one of (1) to (8), wherein the image carrier is a photoreceptor in which a filler is dispersed.
(10) The image carrier has an organic photoreceptor having a surface layer reinforced with a filler, an organic photoreceptor using a crosslinked charge transport material, or a surface layer reinforced with a filler and has a crosslinked type. The image forming apparatus according to any one of (1) to (8), wherein the image forming apparatus is an organic photoreceptor using a charge transport material.
(11) The image forming apparatus according to any one of (1) to (8), wherein the image carrier is an amorphous silicon photoconductor.

According to the first aspect of the present invention, since the lubricant on the surface of the image carrier can be removed efficiently, a high-quality image can always be obtained, and the image carrier can be used for a long time.
According to the second aspect of the present invention, since the lubricant on the surface of the image carrier can be efficiently removed, a high-quality image can always be obtained, and the image carrier can be used for a long time.
According to the invention of claim 3, in the image forming apparatus of claim 1, the toner used is a ratio (Dv / Dn) of volume average particle diameter (Dv) to number average particle diameter (Dn). In the range of 1.00 to 1.40, the development stability in the developer is reduced due to the accumulation of fine powder, the transfer quality is deteriorated due to uneven distribution, the cleaning property is reduced due to the increase in fine powder, the hard fine powder (small particles) The increase in the digging of the image carrier and the shortening of the life of the image carrier due to the increase in the diameter toner) are effectively prevented, and high-quality printing can be performed without causing problems as a series of processes of the image forming apparatus.
According to the fourth aspect of the present invention, the amount of particles of 2 μm or less in the toner is 1 to 10% by number, thereby preventing an increase in the digging of the image carrier due to an increase in the hard fine toner and shortening of the life of the image carrier. be able to.
According to the fifth aspect of the present invention, fluidity, charging characteristics, and the like can be imparted to the toner, and at the same time, the BET specific surface area of the toner base can be increased, so that the deteriorated lubricant can be efficiently removed. it can.
According to the sixth aspect of the present invention, the toner fluidity is improved and the toner can be easily separated from the surface of the image carrier by containing the toner in combination with silica and titanium. Thereby, since the load concerning a cleaning blade edge can be reduced, entrainment of a cleaning blade edge can be suppressed and edge wear can be reduced.
According to the seventh aspect of the present invention, since the lubricant is applied after cleaning, the lubricant can be applied to the entire surface of the image carrier after the toner is cleaned. Thereby, since the surface property of the lubricant on the surface of the image carrier can be made more uniform, stick slip of the cleaning blade edge can be reduced as much as possible.
According to the invention described in claim 8, in general, the lubricant applied by the lubricant applying means often exists in the form of grains on the surface of the image carrier, and covers the entire surface of the image carrier. The friction coefficient distribution is greatly generated on the surface of the image carrier, and the lubricant applied on the surface of the image carrier by providing a lubricant applying means and a lubricant leveling means. Is stretched to the surface of the image carrier and covers the entire surface, thereby reducing the friction coefficient distribution as much as possible and, as a result, reducing edge wear.
According to the invention of claim 9, by using an image carrier having a hard surface layer, fine powder is accumulated in the developing device over time, and even when these are developed and used in the process, the image carrier The body can be used stably over a long period of time.
According to the invention described in claim 10, by using an image carrier having a hard surface layer, fine powder is accumulated in the developing device over time, and even when they are developed and used in the process, the image carrier The body can be used stably over a long period of time.
According to the invention described in claim 11, by using an image carrier having a hard surface layer, fine powder is accumulated in the developing device over time, and even when they are developed and used in the process, the image carrier The body can be used stably over a long period of time.

Hereinafter, the best mode for carrying out the invention will be described, but the present invention is not limited to this.
The present invention can be applied to the image forming apparatus illustrated in FIGS. 3, 4, and 5 using an electrophotographic method, and the image forming apparatus is the same as that described above based on FIGS. 1 and 2. Since it overlaps in part, explanation of the overlapping part is omitted.

  A plurality of cleaning means (7) may be mounted. At this time, as the shape of the cleaning blade, a blade having an obtuse angle (90 to 180 °) at the tip of the blade edge that contacts the image carrier (8) may be used when contacting with the counter. By adopting such a blade shape, the blade contact pressure to the image carrier can be increased, and the cleaning property can be improved. In addition, a method of electrostatically cleaning the toner on the surface of the image carrier by applying a voltage to such a cleaning unit may be used in combination.

  Examples of the cleaning auxiliary means (11) include a fur brush, an elastic roller, a tube covering roller, and a nonwoven fabric. A plurality of these may be mounted. At this time, a cleaning property may be improved by applying a voltage to the cleaning assisting means and controlling the polarity of the toner. Further, a loop brush configured so that the bristles have a loop shape may be used, and the cleaning auxiliary brush may be omitted.

  Examples of the lubricant leveling means (12) include a blade-shaped cleaning blade made of polyurethane rubber, silicone rubber, nitrile rubber, chloroprene rubber or the like. A plurality of cleaning blades may be mounted. At this time, as the shape of the lubricant leveling blade, a blade having an obtuse angle (90 to 180 °) at the tip of the blade edge contacting the image carrier (8) may be used when contacting with the counter. By adopting such a blade shape, the blade contact pressure to the image carrier can be increased, and the lubricant leveling efficiency can be improved. Further, by applying a voltage to the lubricant leveling means (12), the toner that has passed through the cleaning means (7) is electrostatically cleaned from the surface of the image carrier. Also good. The contact of the lubricant leveling blade (12) with the image carrier (8) may be trailing or countering with respect to the image carrier rotation direction.

As the lubricant application means (6), in addition to a method of applying to the image carrier by a fur brush, loop brush, roller, or belt, a solid lubricant or lubricant powder is directly applied to the image carrier (8). It may be a method. Moreover, you may use the loop brush comprised so that a bristle tip might become a loop shape.
The lubricant consists of a fatty acid metal salt, which contains one or more fatty acids selected from the group of stearic acid, palmitic acid, myristic acid, oleic acid, zinc, aluminum, calcium, magnesium, iron It contains at least one metal selected from the group of lithium and is formed by solidifying a powdered fatty acid metal salt. The powder before solidification is preferably a finer powder. Zinc stearate is a typical lamellar crystal powder, but it is preferred to use such materials as lubricants. A lamellar crystal has a layered structure in which amphiphilic molecules are self-organized, and when a shearing force is applied, the crystal is broken and slips easily along the layer. This action is effective in reducing the friction coefficient, and the characteristic of the lamella crystal that uniformly covers the surface of the photoreceptor 2 by receiving a shearing force is that the surface of the photoreceptor 2 can be effectively covered by a small amount of the lubricant 7. it can.
Since the fatty acid metal salt has a linear hydrocarbon structure, slippage between layers is likely to occur, and good lubricity is exhibited. Moreover, in the case of such a linear fatty acid metal salt, it can have favorable weather resistance by selecting a metal.

The fatty acid metal salt is desirably applied to the image carrier in an amount specified as follows.
That is, the amount of lubricant applied to the image carrier (charged body) is in the range represented by the following mathematical formulas 1 to 3,
Ratio of element number A of specific element of lubricant detected by XPS with respect to the total number of elements of all elements of material constituting the outermost surface of the object to be detected detected by an X-ray photoelectron spectrometer (XPS) A [ %]
[Equation 1]
A ≧ 1.52 × 10 ⁻⁴ × {Vpp−2 × Vth} × f / v × Nα
(Where Vpp is the peak-to-peak voltage value [unit: V] of the AC voltage, f is the frequency [unit: Hz] of the AC component applied to the charging means (1), and v is the moving speed of the charged object surface [ (Unit: mm / sec], Nα is the number of elements in one molecule of the specific element among the elements constituting the lubricating material, and Vth is the discharge start voltage, which is determined by the following equation (2).
[Equation 2]
Vth = 312 + 6.2 × (d / εopc + Gp / εair) + √ (7737.6 × d / εopc)
(At this time, d is the film thickness [unit: μm] of the member to be charged, εopc is the relative dielectric constant of the member to be charged, and εair is the dielectric constant in the space between the member to be charged (8) and the charging means (1). Gp is the closest distance [unit: μm] between the surface of the charging means (1) and the surface of the member to be charged.
The ratio B (%) of the number of elements constituting the lubricating material detected by XPS with respect to the total number of elements of all elements constituting the outermost surface of the image carrier detected by XPS is as follows: Equation 3] is satisfied.
[Equation 3]
B ≧ 1.52 × 10 ⁻⁴ × {Vpp−2 × Vth} × f / v × Nβ
(Here, Nβ: a value obtained by subtracting the number of hydrogen elements from the total number of elements constituting one molecule of the lubricating substance.)
(The lubricating material is a fatty acid metal salt, the specific element is a metal, Nα is 1, and Nβ is 41. The closest distance between the charging means and the image carrier is 1 to 100 [ μm])

Further, the toner used for developing the electrostatic latent image on the image carrier by the developing means is a toner granulated in an aqueous system, and at least a binder resin, a colorant, and a modified layered inorganic The toner preferably contains a mineral and has a BET specific surface area of 2.5 to 7.0 (m ² / g).

(Toner production method)
The toner of the present invention can be produced by the following method.
It is effective to contain at least a modified layered inorganic mineral in the toner.
Further, this toner includes a prepolymer comprising at least a binder resin and a modified polyester resin in an organic solvent, a compound that extends or crosslinks with the prepolymer, a colorant, a release agent, a modified layered inorganic mineral (organic modified clay). Is a toner in which 0.05 to 10% of a modified layered inorganic mineral (organic modified clay) is contained in the solid content of the solution or dispersion. It is desirable.
At this time, the toner contains at least an organic solvent containing a binder resin, a modified polyester resin, a compound that extends or crosslinks with the prepolymer, a colorant, a release agent, a modified layered inorganic mineral (organic modified clay). ) Is dissolved or dispersed, the Casson yield value at 25 ° C. of the solution or dispersion is 1 to 100 Pa, and the solution or dispersion is subjected to a crosslinking reaction and / or elongation reaction in an aqueous medium. The toner is preferably obtained by removing the solvent from the dispersion. If the Casson yield value is less than 1 Pa, it is difficult to obtain the target shape, and if it exceeds 100 Pa, the productivity deteriorates. Moreover, it is preferable that 0.05-10% of this organic modified clay is contained in the solid content in this solution or dispersion. If it is less than 0.05%, the target Casson yield value cannot be obtained, and if it exceeds 10%, the fixing performance deteriorates. Moreover, it is preferable that 0.05-10% of this organic modified clay is contained in the solid content in this solution or dispersion. If it is less than 0.05%, the target Casson yield value cannot be obtained, and if it exceeds 10%, the fixing performance deteriorates.
A more detailed description of the toner manufacturing method is shown below.

(Casson yield measurement method)
The Casson yield value can be measured using a high shear viscometer or the like.
The measurement conditions are as follows.
Device: AR2000 (TA Instruments)
Shear stress 120Pa / 5min Geometry: 40mm steel plate Geometry gap: 1mm
Analysis software: TA DATA ANALYSIS (TA Instruments)

(Modified layered inorganic mineral)
Modified layered inorganic minerals are (i) “organic modified silicates (organic cation modified silicates)” and (ii) “organic modified hydrotalcite (organic anion modified hydrotalcite)” (layered mineral [+ multivalent metal]). And the layered side is considered as a concept containing cations). Representative examples of the modified layered inorganic mineral include organic modified montmorillonite and organic modified smectite.

Organically modified silicate (organic cation modified silicates):
The modified layered inorganic mineral used in the toner of the present invention is a layered inorganic mineral having a smectite-based basic crystal structure in which at least some of the ions in the interlayer are modified with organic ions, but those modified with organic cations are used. desirable.
Examples of the layered inorganic mineral modified with an organic cation include montmorillonite or bentonite, beidellite, nontronite, saponite, hectorite and the like.
Examples of the organic cation modifier for the modified layered inorganic mineral include quaternary alkyl ammonium salts, phosphonium salts, imidazolium salts, and the like, and quaternary alkyl ammonium salts are preferable. Examples of the quaternary alkylammonium include trimethylstearylammonium, dimethylstearylbenzylammonium, dimethyloctadecylammonium, oleylbis (2-hydroxyethyl) methylammonium and the like.

  Examples of the modified layered inorganic mineral include bentonite modified with an organic cation, such as BENTONE34, BENTONE52, BENTONE38, BENTONE27, BENTONE57, BENTONE SD1, BENTONE SD2, BENTONE SD3, etc., manufactured by ELEMENTIS. As modified products, CRAYTONE34, CRAYTONE40, CRAYTONE HT, CRAYTONE2000, CRAYTONE AF, CRAYTONE APA, CRAYTONE HY, etc. manufactured by HOJUN, S.B. , Esven NX, Esben NX80, Sven NO12S, S-BEN NEZ, S-BEN NO12, S-BEN WX, S-BEN NE, etc., Kunimine Industries, Ltd. Kunibisu 110, Kunibisu 120, Kunibisu 127, and the like.

  The modified layered inorganic mineral has a volume average particle diameter Dv of 0.1 μm to 0.55 μm, and the modified layered inorganic mineral having a volume average particle diameter of 1 μm or more needs to satisfy 15% or less. When the volume average particle diameter Dv exceeds 0.55 μm, or the frequency of the particle diameter of 1 μm or more exceeds 15%, the effect on the toner shape and toner charging performance decreases. In order to make the particle size of the modified layered inorganic mineral within the above range, the modified layered inorganic mineral is preferably used as a kneaded composite with the binder resin, that is, a masterbatch, and in the masterbatch and in the dispersion, The volume average particle diameter Dv of the modified layered inorganic mineral is preferably 0.1 μm to 0.55 μm, and the modified layered inorganic mineral having a volume average particle diameter of 1 μm or more is preferably 15% or less.

The kneaded composite of the modified layered inorganic mineral and the binder resin, that is, the master batch, is obtained by mixing and kneading the binder resin and the modified layered inorganic mineral modified with an organic cation with high shear force to obtain a master batch. Can do. At this time, an organic solvent can be used to enhance the interaction between the modified layered inorganic mineral and the binder resin. Also, a so-called flushing method is a method in which an aqueous paste containing the modified layered inorganic mineral and water is mixed and kneaded together with a resin and an organic solvent, and the modified layered inorganic mineral is transferred to the resin side to remove moisture and organic solvent components. Also, since the wet cake can be used as it is, it does not need to be dried and is preferably used. For mixing and kneading, a high shear dispersion device such as a three-roll mill is preferably used.
As the raw material of the modified layered inorganic mineral, it is preferable to use a material having a volume average particle diameter Dv of 0.1 to 5 μm when present as at least an aggregate.

Organically modified hydrotalcite (organic anion modified hydrotalcite) ”(layered mineral [+ multivalent metal], layered side is cation:
Organic anion modification produced mainly by reaction of commercially available hydrotalcites in aqueous, organic (eg alcohol) or aqueous-organic suspensions with organic anions (eg in the form of their salts) A hydrotalcite can be illustrated (refer to Japanese translations of PCT publication No. 2006-500605 gazette and special gazette 2006-503313 gazette).

  The toner suitably used in the image forming apparatus of the present invention includes a toner material liquid in which at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent are dispersed in an organic solvent. A toner obtained by crosslinking and / or elongation reaction in an aqueous solvent.

(polyester)
The polyester is obtained by a polycondensation reaction between a polyhydric alcohol compound and a polycarboxylic acid compound.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable. Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyhydric alcohol (TO) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.
Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) with a small amount of (TC) Mixtures are preferred. Divalent carboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).
The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.
The polycondensation reaction between a polyhydric alcohol (PO) and a polycarboxylic acid (PC) is carried out in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and heated to 150 to 280 ° C. while reducing the pressure as necessary. The produced water is distilled off to obtain a polyester having a hydroxyl group. The hydroxyl value of the polyester is preferably 5 or more, and the acid value of the polyester is usually 1 to 30, preferably 5 to 20. By giving an acid value, it tends to be negatively charged, and furthermore, when fixing to a recording paper, the affinity between the recording paper and the toner is good and the low-temperature fixability is improved. However, when the acid value exceeds 30, there is a tendency to deteriorate with respect to the stability of charging, particularly environmental fluctuation.

  The weight average molecular weight of the polyester is 10,000 to 400,000, preferably 20,000 to 200,000. A weight average molecular weight of less than 10,000 is not preferable because offset resistance deteriorates. On the other hand, if it exceeds 400,000, the low-temperature fixability is deteriorated.

  In addition to the unmodified polyester obtained by the above polycondensation reaction, the polyester preferably contains a urea-modified polyester. The urea-modified polyester is obtained by reacting a terminal carboxyl group or hydroxyl group of the polyester obtained by the above polycondensation reaction with a polyvalent isocyanate compound (PIC) to obtain a polyester prepolymer (A) having an isocyanate group. It is obtained by cross-linking and / or extending the molecular chain by the reaction of the amine with amines.

Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) ); Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; Those blocked with caprolactam or the like; and combinations of two or more of these.
The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, when a urea-modified polyester is used, the urea content in the ester is lowered and hot offset resistance is deteriorated.

The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.
The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acid block of B1 to B5 (B6).
Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like.
Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of the compound (B6) obtained by blocking the amino group of B1 to B5 include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated.
The urea-modified polyester may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

The urea-modified polyester is produced by a one-shot method or the like. Polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) are heated to 150-280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate, dibutyltin oxide, etc., and water generated while reducing the pressure as necessary. Distill off to obtain a polyester having a hydroxyl group. Subsequently, at 40-140 degreeC, this is made to react with polyvalent isocyanate (PIC), and the polyester prepolymer (A) which has an isocyanate group is obtained. Further, this (A) is reacted with amines (B) at 0 to 140 ° C. to obtain a urea-modified polyester.
When reacting (PIC) and when reacting (A) and (B), a solvent may be used if necessary. Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to isocyanates (PIC), such as tetrahydrofuran (such as tetrahydrofuran).
In addition, in the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B), a reaction terminator can be used as necessary to adjust the molecular weight of the resulting urea-modified polyester. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

  The weight average molecular weight of the urea-modified polyester is usually 10,000 or more, preferably 20,000 to 10,000,000, and more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of the urea-modified polyester or the like is not particularly limited when the above-mentioned unmodified polyester is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. When the urea-modified polyester is used alone, its number average molecular weight is usually 2000-15000, preferably 2000-10000, more preferably 2000-8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color apparatus are deteriorated.

By using the unmodified polyester and the urea-modified polyester in combination, the low-temperature fixability and the glossiness when used in a full-color image forming apparatus are improved. Therefore, it is preferable to use the urea-modified polyester alone. The unmodified polyester may include a polyester modified with a chemical bond other than a urea bond.
The unmodified polyester and the urea-modified polyester are preferably at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Therefore, it is preferable that the unmodified polyester and the urea-modified polyester have a similar composition.
The weight ratio of unmodified polyester to urea-modified polyester is usually 20/80 to 95/5, preferably 70/30 to 95/5, more preferably 75/25 to 95/5, and particularly preferably 80 /. 20-93 / 7. When the weight ratio of the urea-modified polyester is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.
Glossiness when used in a full-color device deteriorates.

The glass transition point (Tg) of the binder resin containing unmodified polyester and urea-modified polyester is usually 45 to 65 ° C, preferably 45 to 60 ° C. If it is less than 45 ° C., the heat resistance of the toner deteriorates, and if it exceeds 65 ° C., the low-temperature fixability becomes insufficient.
In addition, since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the heat-resistant storage stability tends to be good even when the glass transition point is low as compared with known polyester-based toners.

(Coloring agent)
As the colorant, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher , Yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R , Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thio Indigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Lid Russian nin green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

  The colorant can also be used as a master batch combined with a resin. As a binder resin to be kneaded together with the production of the master batch or the master batch, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyl toluene or the like, or a copolymer of these and a vinyl compound, Polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be mentioned, and these can be used alone or in combination.

(Charge control agent)
Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salts or compounds, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit) Manufactured), copper phthalocyanine, perylene, quinacridone, azo series Fee, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used. The amount of the charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the developer fluidity is lowered, and the image density is lowered. Invite.
The charge control agent can be melt-kneaded together with the master batch and the binder resin, or may be added when dissolved and dispersed in an organic solvent.

(Release agent)
As a release agent, a low melting point wax having a melting point of 50 to 120 ° C. works more effectively as a release agent in the dispersion with the binder resin between the fixing roller and the toner interface. The effect on high temperature offset is exhibited without applying a release agent such as oil. Examples of such a wax component include the following. Examples of waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, and paraffin, microcrystalline, And petroleum waxes such as petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones, and ethers can be used. Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbon, and low molecular weight crystalline polymer resin, poly-n-stearyl methacrylate, poly-n- A crystalline polymer having a long alkyl group in the side chain such as a homopolymer or copolymer of polyacrylate such as lauryl methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be used. .
The release agent can be melt-kneaded together with the master batch and the binder resin, or may be added when dissolved and dispersed in an organic solvent.

(Manufacture of toner)
Next, the toner manufacturing method will be described in more detail. Here, although a preferable manufacturing method is shown, it is not limited to this.
(1) A toner material solution is prepared by dispersing a colorant, unmodified polyester, a polyester prepolymer having an isocyanate group, and a release agent in an organic solvent.
The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation. Specifically, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, Methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable. The usage-amount of an organic solvent is 0-300 weight part normally with respect to 100 weight part of polyester prepolymers, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part.

(2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles.
The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.
The amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical.
Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.

As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride, fatty acid amide derivatives, polyhydric alcohols Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine And the like.
Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-Hydroxyethyl) Perful Olooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.
Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).
Moreover, as the cationic surfactant, aliphatic quaternary ammonium such as aliphatic primary, secondary or secondary amic acid, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt which has a right fluoroalkyl group is used. Salt, benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (manufactured by Asahi Glass), Florard FC-135 (manufactured by Sumitomo 3M), Unidyne DS-202 (Daikin Industries) Smoke), Megafac F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products), Footage F-300 (Neos), and the like.

The resin fine particles are added to stabilize the toner base particles formed in the aqueous medium. For this reason, it is preferable to add so that the coverage existing on the surface of the toner base particles is in the range of 10 to 90%. For example, polymethyl methacrylate fine particles 1 μm and 3 μm, polystyrene fine particles 0.5 μm and 2 μm, poly (styrene-acrylonitrile) fine particles 1 μm, trade names are PB-200H (manufactured by Kao), SGP (manufactured by Soken), Techno Examples include polymer SB (manufactured by Sekisui Chemical Co., Ltd.), SGP-3G (manufactured by Sokensha), and micropearl (manufactured by Sekisui Fine Chemical Co., Ltd.).
In addition, inorganic compound dispersants such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite can also be used.

As a dispersant that can be used in combination with the above resin fine particles and inorganic compound dispersant, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid-γ-hydroxy Propyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Luric acid esters, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl Nitrogen compounds such as imidazole and ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, poly Xoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxy Polyoxyethylenes such as ethylene nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. Among these, the high-speed shearing method is preferable in order to make the particle size of the dispersion 2 to 20 μm. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C.

(3) At the same time as the preparation of the emulsion, the amines (B) are added to cause a reaction with the polyester prepolymer (A) having an isocyanate group. This reaction involves molecular chain crosslinking and / or elongation. The reaction time is selected depending on the reactivity between the isocyanate group structure of the polyester prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

(4) After completion of the reaction, the organic solvent is removed from the emulsified dispersion (reactant), washed and dried to obtain toner base particles.
In order to remove the organic solvent, the temperature of the entire system is gradually raised in a laminar stirring state, and after giving strong stirring in a certain temperature range, the solvent base is removed to produce spindle-shaped toner base particles. . Further, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner base particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. Remove. It can also be removed by operations such as enzymatic degradation.

(5) A charge control agent is injected into the toner base particles obtained above, and then inorganic fine particles such as silica fine particles and titanium oxide fine particles are externally added to obtain a toner. The injection of the charge control agent and the external addition of the inorganic fine particles are performed by a known method using a mixer or the like. Thereby, a toner having a small particle size and a sharp particle size distribution can be easily obtained. Furthermore, by giving strong agitation in the process of removing the organic solvent, the shape between the true spherical shape and the rugby ball shape can be controlled, and the surface morphology is also controlled between the smooth shape and the umeboshi shape. be able to.

  The toner used in the present invention preferably has a volume average particle diameter of 3 to 8 μm in order to reproduce minute dots of 600 dpi or more. The ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is preferably in the range of 1.00 to 1.40. The closer (Dv / Dn) is to 1.00, the sharper the particle size distribution. With such a toner having a small particle size and a narrow particle size distribution, the toner charge amount distribution is uniform, a high-quality image with little background fogging can be obtained, and the electrostatic transfer method has a high transfer rate. can do.

The toner used in the present invention preferably contains 1 to 10% by number of particles of 2 μm or less.
As a result, the image carrier can be used for a long time.

  The toner used in the present invention is preferably prepared by externally adding a plurality of inorganic fine particles. As the inorganic fine particles, those having an average primary particle size of 10 nm to 150 nm are preferably used.

The toner used in the present invention preferably contains at least silica and titanium. Silica having an average primary particle size of 10 nm to 150 nm may be used, and a plurality of silicas having different average primary particle sizes may be used. In particular, silica is preferably used in combination of those having an average primary particle size of 50 nm or less and those having an average primary particle size of 50 nm or more. And especially silica uses H2000, H1303, H3004 (made by Nippon Aerosil Co., Ltd.), X24 (made by Shin-Etsu Chemical Co., Ltd.), NHM-3N (made by Tokuyama Co., Ltd.), UFP30HH, UFP35HH, UFP40HH (made by Electrochemical Co., Ltd.), etc. It is good to do.
Titanium having an average primary particle size of 50 nm or less is preferably used. In particular, it is preferable to use SMT150AI, SMT150AFM, JMT150IB, JMT500IB (manufactured by Takeca) or the like.

Next, a measurement method relating to the properties and the like of the toner of the present invention will be shown.
(Particle size distribution)
Examples of the measuring device for the particle size distribution of toner particles by the Coulter counter method include Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). The measurement method is described below.
First, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of an aqueous electrolytic solution. Here, the electrolytic solution is a solution prepared by preparing a 1% NaCl aqueous solution using primary sodium chloride. For example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the measurement device is used to measure the volume and number of toner particles or toner using a 100 μm aperture as an aperture. Volume distribution and number distribution are calculated. From the obtained distribution, the weight average particle diameter (D4) and the number average particle diameter of the toner can be obtained.
As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Uses 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm. In addition, a flow type particle image analyzer (“FPIA-2100”; manufactured by Sysmex Corporation) is used for measurement of ultrafine toner of 2 μm or less, and analysis software (FPIA-2100 Data Processing Program for FPIA version 00-10) is used. Analysis.
Specifically, 0.1 to 0.5 ml of 10 wt% surfactant (alkylbenzene sulfonate Neogen SC-A; Daiichi Kogyo Seiyaku) is added to a glass 100 ml beaker, and each toner 0.1 to 0 is added. 0.5 g was added and stirred with a micropartel, and then 80 ml of ion-exchanged water was added. The obtained dispersion was subjected to a dispersion treatment for 3 minutes with an ultrasonic disperser (manufactured by Honda Electronics Co., Ltd.). The shape and distribution of the toner were measured using the FPIA-2100 until the density of the dispersion was 5000 to 15000 / μl. In this measurement method, it is important that the concentration of the dispersion liquid is 5000 to 15000 / μl from the viewpoint of measurement reproducibility of the average circularity. In order to obtain the dispersion concentration, it is necessary to change the conditions of the dispersion, that is, the amount of surfactant to be added and the amount of toner. The amount of the surfactant varies depending on the hydrophobicity of the toner as in the measurement of the toner particle diameter described above. If it is added in a large amount, noise due to bubbles is generated. If the amount is too small, the toner cannot be sufficiently wetted. It becomes insufficient. Further, the toner addition amount differs from the particle size, and it is necessary to decrease the small particle size and increase the large particle size. When the toner particle size is 3 to 7 μm, the toner amount is 0.1 to 0. By adding 0.5 g, the dispersion concentration can be adjusted to 5000 to 15000 / μl.

(2μm or less grain size)
The particle ratio of 2 μm or less and the circularity of the toner of the present invention can be measured by a flow type particle image analyzer FPIA-2000 (manufactured by Toa Medical Electronics Co., Ltd.). As a specific measuring method, 0.1 to 0.5 ml of a surfactant, preferably alkylbenzene sulfonate is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance, and further measurement is performed. Add about 0.1-0.5g of sample. The suspension in which the sample is dispersed is obtained by performing dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and measuring the shape and distribution of the toner with the above apparatus at a dispersion concentration of 3000 to 10,000 / μl. .

(Molecular weight)
The molecular weight according to the present invention is measured by GPC (gel permeation chromatography) as follows. Stabilize the column in a heat chamber at 40 ° C., flow THF at a flow rate of 1 ml / min through the column at this temperature, and prepare a THF sample solution of resin prepared at a sample concentration of 0.05 to 0.6% by weight. Is measured by injecting 50 to 200 μl. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of the prepared calibration curve and the count using several types of monodisperse polystyrene standard samples. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical Co. Or molecular weight made by Toyo Soda Industry Co., Ltd. is 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9. It is suitable to use x10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ , and use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

(Acid value)
Measurement is performed under the following conditions in accordance with the measurement method described in JIS K0070-1992.
Sample preparation: 0.5 g of polyester (0.3 g for ethyl acetate-soluble component) is added to 120 ml of toluene and dissolved by stirring at room temperature (23 ° C.) for about 10 hours. Further, 30 ml of ethanol is added to prepare a sample solution.
The measurement can be calculated by the apparatus described above, but specifically, the calculation is performed as follows.
Titrate with a pre-standardized N / 10 caustic potash to alcohol solution, and determine the acid value from the consumption of the alcohol potash solution by the following calculation.
Acid value = KOH (ml) x N x 56.1 / sample weight (where N is a factor of N / 10 KOH)

(Hydroxyl value)
Weigh accurately 0.5 g of sample into a 100 ml volumetric flask and add 5 ml of acetylating reagent correctly. Then, it is immersed in a bath at 100 ° C. ± 5 ° C. and heated. After 1-2 hours, the flask is removed from the bath, allowed to cool, water is added and shaken to decompose acetic anhydride. Furthermore, in order to complete the decomposition, the flask is again heated in a bath for 10 minutes or more and allowed to cool, and then the wall of the flask is thoroughly washed with an organic solvent. This solution is subjected to potentiometric titration with an N / 2 potassium hydroxide ethyl alcohol solution using the electrode to determine the OH value (according to JISK0070-1966).

(Glass transition point)
As a device for measuring Tg, a TG-DSC system TAS-100 manufactured by Rigaku Corporation is used. First, about 10 mg of a sample is placed in an aluminum sample container, which is placed on a holder unit and set in an electric furnace. After heating from room temperature to 150 ° C. at a rate of temperature increase of 10 ° C./min, the sample is allowed to stand at 150 ° C. for 10 minutes, cooled to room temperature and left for 10 minutes, and again at a temperature increase rate of 10 ° C./min. Heat and perform DSC measurement. Tg is calculated from the contact point between the tangent line and the base line of the endothermic curve near Tg, using the analysis system in the TAS-100 system.

Next, the image forming apparatus of the present invention will be described.
As shown in FIG. 3, the image forming apparatus of the present invention preferably has a lubricant applying means (6) downstream of the image carrier rotating direction cleaning means. As shown in FIG. 4, a lubricant application means (6) is provided downstream of the image carrier rotation direction cleaning means, and a lubricant leveling means (12) is provided downstream of the lubricant application means and upstream of the charging means. ) Is preferably provided.

  In such a configuration, at the time of image formation, the image carrier (8) and the lubricant application means (fur brush) (6) rotate, and the fur brush (6) rotates, so that the lubricant (5) becomes the fur brush. It is scraped off by (6) and adheres to the fur brush (6), and the lubricant adhering to the fur brush (6) is applied to the surface of the image carrier (8). The lubricant applied to the surface of the image carrier (8) is leveled into a thin layer by the elastic blade 9, and a thin layer of lubricant having a substantially uniform thickness is formed on the surface of the image carrier (8). .

  In the image forming apparatus of the present invention, the image bearing member (8) is preferably an organic photoreceptor having a layer in which filler is dispersed and reinforced on the surface layer. Accordingly, the life of the image carrier is further increased by using an organic photoreceptor having a layer in which a filler is dispersed and strengthened on the surface layer of the image carrier (8). Further, by using an image carrier having improved wear resistance, the surface of the image carrier can be easily kept flat. For this reason, the toner is not trapped by fine irregularities on the surface, and thus the cleaning property is easily maintained.

(Description of organophotoreceptor with filler dispersed in surface layer)
It is a photoreceptor in which a filler is added to the protective layer for the purpose of improving wear resistance. Examples of organic fillers include fluororesin powders such as polytetrafluoroethylene, silicone resin powders, and a-carbon powders. Inorganic fillers include metal powders such as copper, tin, aluminum, and indium, tin oxide, and oxidation. Examples thereof include zinc, titanium oxide, indium oxide, antimony oxide, bismuth oxide, tin oxide doped with antimony, metal oxides such as tin-doped indium oxide, and inorganic materials such as potassium titanate. These fillers may be used alone or in combination of two or more. These fillers can be dispersed by using a suitable disperser in the protective layer coating solution. Moreover, it is preferable from the point of the transmittance | permeability of a protective layer that the average particle diameter of a filler is 0.5 micrometer or less, Preferably it is 0.2 micrometer or less. In the present invention, a plasticizer or a leveling agent may be added to the protective layer.

In the image forming apparatus of the present invention, the image carrier is preferably an organic photoreceptor using a crosslinkable charge transport material. Accordingly, the life of the image carrier is further increased by using an organic photoreceptor having a layer in which filler is dispersed and strengthened on the surface layer of the image carrier.
Further, by using an image carrier having improved wear resistance, the surface of the image carrier can be easily kept flat. For this reason, the toner is not trapped by fine irregularities on the surface, and thus the cleaning property is easily maintained. Hereinafter, the image carrier having a crosslinked structure will be described.

(Description of cross-linking type protective layer)
As the binder composition of the protective layer, a protective layer having a crosslinked structure is also effectively used. Regarding the formation of a cross-linked structure, a reactive monomer having a plurality of cross-linkable functional groups in one molecule is used to cause a cross-linking reaction using light or heat energy to form a three-dimensional network structure. is there. This network structure functions as a binder resin and exhibits high wear resistance. From the viewpoint of electrical stability, printing durability, and life, it is a very effective means to use a monomer having a charge transporting ability in whole or in part as the reactive monomer. By using such a monomer, a charge transporting site is formed in the network structure, and the function as a protective layer can be sufficiently expressed.
As the reactive monomer having charge transporting ability, a compound containing at least one charge transporting component and a silicon atom having a hydrolyzable substituent in the same molecule, and a charge transporting component in the same molecule A compound containing a hydroxyl group, a compound containing a charge transporting component and a carboxyl group in the same molecule, a compound containing a charge transporting component and an epoxy group in the same molecule, a charge transporting component in the same molecule And a compound containing an isocyanate group. These charge transport materials having a reactive group may be used alone or in combination of two or more. More preferably, a reactive monomer having a triarylamine structure is effectively used as the monomer having a charge transporting ability because of high electrical and chemical stability and high carrier mobility.

  In addition to this, monofunctional and bifunctional polymerizable monomers and polymerizable oligomers are used in combination for the purpose of imparting functions such as viscosity adjustment during coating, stress relaxation of the cross-linked charge transport layer, lower surface energy and reduced friction coefficient. be able to. As these polymerizable monomers and oligomers, known ones can be used.

  In the present invention, the hole transporting compound is polymerized or cross-linked using heat or light, but when the polymerization reaction is performed by heat, the polymerization reaction proceeds when the polymerization reaction proceeds only with thermal energy. Although it may be necessary, in order to advance the reaction efficiently at a lower temperature, it is preferable to add an initiator. In the case of polymerization by light, it is preferable to use ultraviolet light as light, but the reaction rarely proceeds only by light energy, and generally a photopolymerization initiator is used in combination. The polymerization initiator in this case mainly absorbs ultraviolet rays having a wavelength of 400 nm or less, generates active species such as radicals and ions, and starts polymerization. In the present invention, the aforementioned heat and photopolymerization initiators can be used in combination.

  The charge transport layer having a network structure formed in this manner has high wear resistance, but has a large volume shrinkage during the crosslinking reaction, and if it is too thick, it may cause cracks. In such a case, the protective layer may be a laminated structure, a low molecular dispersion polymer protective layer may be used for the lower layer (photosensitive layer side), and a protective layer having a crosslinked structure may be formed on the upper layer (surface side). Good.

An example of creating an image carrier using the above-mentioned crosslinked type protective layer is shown below.
(Image carrier A)
An image carrier A was prepared in the same manner as the image carrier except that the protective layer coating solution, film thickness and preparation conditions were changed as follows.
182 parts by weight of methyltrimethoxysilane, 40 parts by weight of dihydroxymethyltriphenylamine, 225 parts by weight of 2-propanol, 106 parts by weight of 2% acetic acid, and 1 part by weight of aluminum trisacetylacetonate were mixed to prepare a coating solution for the protective layer. Prepared. This coating solution was applied onto the charge transport layer and dried, followed by heat curing at 110 ° C. for 1 hour to form a protective layer having a thickness of 3 μm.
(Image carrier B)
An image carrier B was prepared in the same manner as the image carrier except that the protective layer coating solution, film thickness and preparation conditions were changed as follows. 30 parts by mass of a hole transporting compound (the following structural formula 1), 0.6 part by mass of an acrylic monomer (the following structural formula 2) and a photopolymerization initiator (1-hydroxy-cyclohexyl-phenyl-ketone) It was dissolved in a mixed solvent of parts by mass / 50 parts by mass of dichloromethane to prepare a coating material for the surface protective layer. This paint was applied on the previous charge transport layer by spray coating, and cured for 30 seconds with a light intensity of 500 mW / cm ² using a metal halide lamp to form a surface protective layer having a thickness of 5 μm.

  In the image forming apparatus of the present invention, the photoreceptor is preferably made of amorphous silicon. Accordingly, the life of the image carrier is further increased by using an organic photoreceptor having a layer in which filler is dispersed and strengthened on the surface layer of the image carrier. Further, by using an image carrier having improved wear resistance, the surface of the image carrier can be easily kept flat. For this reason, the toner is not trapped by fine irregularities on the surface, and thus the cleaning property is easily maintained.

(Amorphous silicon photoconductor)
As the electrophotographic photoreceptor used in the present invention, a conductive support is heated to 50 ° C. to 400 ° C., and a vacuum deposition method, a sputtering method, an ion plating method, a thermal CVD method, a photo CVD is applied on the support. An amorphous silicon photoconductor (hereinafter referred to as “a-Si photoconductor”) having a photoconductive layer made of a-Si can be used by a film forming method such as a plasma CVD method. Among them, a plasma CVD method, that is, a method in which a source gas is decomposed by direct current, high frequency or microwave glow discharge to form an a-Si deposited film on a support is preferably used.

<About layer structure>
The layer structure of the amorphous silicon photoreceptor is, for example, as follows, and FIG. 5 is a schematic configuration diagram for explaining the layer structure. The electrophotographic photoreceptor 500 shown in FIG. 5A is provided with a photoconductive layer 502 made of a-Si: H, X and having photoconductivity on a support 501. An electrophotographic photoreceptor 500 shown in FIG. 5B includes a photoconductive layer 502 made of a-Si: H, X and having photoconductivity, and an amorphous silicon surface layer 503 on a support 501. It is configured. An electrophotographic photoreceptor 500 shown in FIG. 5C has a photoconductive layer 502 made of a-Si: H, X and having photoconductivity on a support 501, an amorphous silicon based surface layer 503, And an amorphous silicon based charge injection blocking layer 504. In the electrophotographic photoreceptor 500 shown in FIG. 5D, a photoconductive layer 502 is provided on a support 501.
The photoconductive layer 502 includes a charge generation layer 505 made of a-Si: H, X and a charge transport layer 506, and an amorphous silicon-based surface layer 503 is provided thereon.

About the support
The support for the photoreceptor may be conductive or electrically insulating. Examples of the conductive support include metals such as Al, Cr, Mo, Au, In, Nb, Te, V, Ti, Pt, Pd, and Fe, and alloys thereof such as stainless steel. Also, at least the surface on the side where the photosensitive layer is formed of an electrically insulating support such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polystyrene, polyamide or other synthetic resin film or sheet, glass or ceramic. A conductively treated support can also be used.
The shape of the support can be a cylindrical or plate-like or endless belt with a smooth or uneven surface, and the thickness thereof is appropriately determined so that a desired photoreceptor for an image forming apparatus can be formed. When flexibility as a photoreceptor for an image forming apparatus is required, it can be made as thin as possible within a range where the function as a support can be sufficiently exhibited. However, the support is usually 10 μm or more from the viewpoints of manufacturing and handling, such as mechanical strength.

<Injection prevention layer>
In the amorphous silicon photoconductor that can be used in the present invention, a charge injection blocking layer that functions to block charge injection from the conductive support side is provided between the conductive support and the photoconductive layer as necessary. It is more effective to provide this (FIG. 5 (c)). That is, the charge injection blocking layer has a function of blocking charge injection from the support side to the photoconductive layer side when the photosensitive layer is subjected to a charging process with a certain polarity on its free surface. When charged, it has a so-called polarity dependency that does not exhibit such a function. In order to provide such a function, the charge injection blocking layer contains a relatively large number of atoms for controlling conductivity as compared with the photoconductive layer. The layer thickness of the charge injection blocking layer is preferably from 0.1 to 5 μm, more preferably from 0.3 to 4 μm, and most preferably from 0.5 to 0.5 in view of obtaining desired electrophotographic characteristics and economic effects. It is desirable to be 3 μm.

<< About photoconductive layer >>
The photoconductive layer is formed on the undercoat layer as necessary, and the layer thickness of the photoconductive layer 502 is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economic effects, preferably It is desirable that the thickness is 1 to 100 μm, more preferably 20 to 50 μm, and most preferably 23 to 45 μm.

<About the charge transport layer>
The charge transport layer is a layer mainly having a function of transporting charges when the photoconductive layer is functionally separated.
The charge transport layer includes at least silicon atoms, carbon atoms, and fluorine atoms as constituent elements, and is formed of a-SiC (H, F, O) including hydrogen atoms and oxygen atoms as required. It has conductive properties, particularly charge retention properties, charge generation properties, and charge transport properties. In the present invention, it is particularly preferable to contain an oxygen atom.
The layer thickness of the charge transport layer is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economic effects. The charge transport layer is preferably 5 to 50 μm, more preferably 10 to 40 μm, Optimally, the thickness is desirably 20 to 30 μm.

《Charge generation layer》
The charge generation layer is a layer mainly having a function of generating charges when the photoconductive layer is functionally separated. This charge generation layer is composed of a-Si: H containing at least silicon atoms as components and substantially no carbon atoms and, if necessary, hydrogen atoms, and has desired photoconductive properties, particularly charge generation properties. , Has charge transport properties. The layer thickness of the charge generation layer is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economic effects, etc., preferably 0.5 to 15 μm, more preferably 1 to 10 μm, optimally 1 ˜5 μm.

<About the surface layer>
If necessary, the amorphous silicon photoconductor that can be used in the present invention can be provided with a surface layer on the photoconductive layer formed on the support as described above. It is preferable to form a surface layer. This surface layer has a free surface, and is provided to achieve the object of the present invention mainly in moisture resistance, continuous repeated use characteristics, electrical pressure resistance, use environment characteristics, and durability.
The layer thickness of the surface layer in the present invention is usually 0.01 to 3 μm, preferably 0.05 to 2 μm, and most preferably 0.1 to 1 μm. If the layer thickness is less than 0.01 μm, the surface layer is lost due to wear or the like during use of the photoreceptor, and if it exceeds 3 μm, electrophotographic characteristics such as an increase in residual potential are observed.

  The present invention is an apparatus for forming an image using the above-described photoreceptor and water-granulated toner, and having a specific amount of lubricant present on the photoreceptor, but the surface of the photoreceptor actually exists. It is generally difficult to measure a small amount of lubricant. However, the present applicant has already succeeded in obtaining knowledge about the lubricant necessary for the surface of the photoreceptor by measuring characteristic elements in the lubricant (see Patent Document 10 and JP-A-006-113499). Issue gazette). The measurement was performed by a Quantum 2000 type scanning X-ray photoelectron spectrometer (XPS) manufactured by PHI under the conditions of an X-ray source AlKα and an analysis region 100 [μm] φ.

  When the lubricant is partially covered on the surface of the photoreceptor, the surface element to be measured is an element constituting the lubricant and the protective layer or charge transport layer constituting the photoreceptor. In this case, in the measurement region, the higher the ratio of surface elements derived from the lubricant, the higher the ratio of the lubricant covering the surface of the photoreceptor. On the other hand, when the lubricant uniformly covers the surface of the photoreceptor and the lubricant is applied thicker than the measurement area in the depth direction, all surface elements measured by XPS are derived from the lubricant. Become. In addition, the lubricant uniformly covers the surface of the photoconductor, but when the lubricant is applied thinner than the measurement region in the depth direction, the surface element measured by XPS covers the lubricant and the photoconductor. It comes from the other layer which comprises.

  Therefore, for example, zinc stearate as a lubricant may be applied to the surface of the photoreceptor and measured by XPS. The measurement is performed, for example, with a diameter of 100 [μm] existing at a depth of 20 to 50 [Å] from the outermost surface of the photoreceptor. Perform in a circle. Here, the surface area of the photoreceptor measured by XPS is composed of at least carbon element (C), oxygen element (O), silicon element (Si), zinc element (Zn), and hydrogen element (H). Further, the elemental zinc (Zn) is configured not to be present in constituent materials other than zinc stearate. Note that the hydrogen element (H) is not detected by the XPS measurement.

An element number ratio [%] of each element detected by XPS with respect to the total number of elements of all elements constituting the surface of the photoreceptor detected by XPS is derived. Since zinc element (Zn) exists only in zinc stearate, the element number ratio [%] of zinc stearate detected by XPS from the element number ratio [%] of this zinc element (Zn), and zinc stearate The ratio of the number of elements [%] detected by XPS of each element constituting can be obtained. Zinc stearate has a molecular formula of [CH ₃ (CH ₂ ) ₁₆ COO] ₂ Zn. One zinc element (Zn) has 36 carbon elements (C), 4 oxygen elements (O), 4 hydrogen elements (Z 70) exists. Of these, hydrogen element (H) is not detected by XPS. Accordingly, the ratio of the number of elements detected by XPS of zinc stearate to the total number of elements of all elements detected by XPS of the substance constituting the surface of the photoreceptor is the ratio of the number of elements of zinc element (Zn) [%]. ] Is multiplied by 41 which is the sum of carbon, oxygen and zinc elements. In addition, the element number ratio [%] of each constituent element detected by XPS of zinc stearate to the total element number of all elements detected by XPS of the substance constituting the photoreceptor surface is the element number ratio [%] of zinc. ] Is multiplied by the number of each element present in one molecule. Even when a lubricant other than zinc stearate is used, knowledge about the amount of lubricant can be obtained if the lubricant contains a characteristic element that does not exist in the photoreceptor.

[Explanation of experiment]
[Experimental Example 1]
The inventors of the present invention conducted the following experiment in order to examine the deterioration state of the surface of the photosensitive member as a member to be charged, which becomes conspicuous in the AC applied discharge by the charging member arranged in contact or close to the charging member. In order to eliminate the deterioration of the surface of the photoreceptor due to mechanical wear, the charging means (1) was disposed in a non-contact manner with respect to the surface of the photoreceptor (8). Further, all the means for contacting the photoreceptor (8) were removed. Then, a non-contact rotating roller-shaped charging means (1) to which a voltage obtained by superimposing an alternating current (AC) voltage bias on a direct current (DC) bias is applied, that is, a photoconductor continuously for about 150 hours using a charging roller. (8) was charged. The photoreceptor (8) used in this experiment is provided with an undercoat layer that is an insulating layer on a support, and further, a charge generation layer (CGL), a charge transport layer (CTL), a surface protective layer ( FR) are sequentially stacked.

  In this photoconductor, the film thickness of the photoconductor decreases as the charging time increases. It is presumed that this is due to chemical deterioration of the surface of the photosensitive member 1 after charging, which becomes noticeable in alternating current application discharge, and film thickness reduction. The details of the mechanism that causes chemical degradation of the surface of the object to be charged, which becomes noticeable in the AC applied discharge by the charging member arranged in contact or close to each other, are under investigation, but the binder resin constituting the charge transport layer and the surface protective layer A carboxylic acid, which is considered to be a decomposition product of polycarbonate, was detected.

  Since it is considered that the components constituting the photoconductor have been decomposed, the mechanism for reducing the film thickness of the photoconductor can be considered as follows. When the energy of particles (ozone, electrons, excited molecules, ions, plasma, etc.) generated by discharge by a charging member placed in contact with or in close proximity is irradiated to the surface protective layer on the surface of the photoreceptor, this energy is transferred to the surface of the photoreceptor. Resonant and absorbed by the binding energy of the molecules constituting the surface layer. And it induces chemical degradation such as a decrease in the degree of entanglement of the polymer chains forming the outermost surface layer, a decrease in molecular weight due to the cleavage of the resin molecular chains, and evaporation of the resin and decomposition products. Along with such chemical deterioration, it is presumed that the outermost surface layer on the surface of the photoreceptor is gradually shaved.

  The film thickness reduction is considered to be caused by the energy of particles generated by the discharge by the charging member arranged in contact with or close to the film. Therefore, it is not a problem peculiar to polycarbonate which is a substance forming the surface layer and the charge transport layer in Experimental Example 1, and it is considered that the same phenomenon occurs also in the photoconductor using other materials.

[Experimental example 2]
Next, a description will be given of an experimental example showing that the chemical deterioration of the surface of the photoconductor, which becomes remarkable in the AC applied discharge, can be suppressed by the presence of a lubricant on the photoconductor. In order to compare the deterioration state of the photoreceptor surface due to the presence or absence of the lubricant on the photoreceptor, a region A where the lubricant is applied and a region B where the lubricant is not applied are provided on the photoreceptor surface. All members other than the charging roller and the lubricant application unit were removed in advance so as not to cause deterioration of the surface of the photoreceptor due to mechanical wear. Then, the charging unit and the lubricant applying unit were continuously driven together with the photoconductor, and the deterioration state of the surface of the photoconductor was examined. The experimental conditions are as follows.

(Experimental conditions)
Charging conditions:
Vpp (peak-to-peak voltage value of AC voltage) = 2.12 [kV]
f (frequency of AC voltage) = 877.2 [Hz]
DC voltage value = −660 [V]
Moving speed of photoreceptor surface v = 125 [mm / s]
Fur brush linear velocity = 216 [mm / sec]
: Zinc stearate

  It was found that the film thickness of the photoconductor after 200 hours of the experiment was compared with the film thickness of the photoconductor before the experiment. In the region B where the lubricant is not applied, the film thickness is reduced by 2.5 [μm], whereas in the region A where the lubricant is applied, the thickness is reduced to 1/8 or less of the reduced film thickness in the region B. Reduced. In addition, when the surface of the photoconductor after the experiment was continuously performed for 200 hours was visually observed, in the region B where the lubricant was not applied, the surface of the photoconductor turned white and deteriorated, In the area A where the lubricant was applied, the same mirror surface as that of the new photoreceptor surface before the experiment was held. From these results, it has been clarified that chemical deterioration of the surface of the photoconductor, which becomes remarkable in the AC applied discharge, can be suppressed by applying a lubricant to the surface of the photoconductor.

[Experimental Example 3]
Next, an experimental example will be described that shows that conditions for suppressing chemical deterioration of the surface of the photoreceptor, which becomes noticeable in AC applied discharge, are different from those for reducing the coefficient of friction of the surface of the photoreceptor. Experimental conditions are basically the same as in Experimental Example 2. However, the lubricant non-existing area B is not provided on the surface of the photoreceptor, and the lubricant is applied to the entire area (area A and area B) of the photoreceptor surface so that the following abundance is present. Different. The coating amount of zinc stearate as a lubricant on the surface of the photoconductor is 0.0002 [mg / mm ² ] and 0.0016 [mg / mm ² ], and the chemicals on the surface of the photoconductor are used for both samples. The presence or absence of deterioration was examined.

As a result, when zinc stearate was applied at 0.0002 [mg / mm ² ], the film thickness on the surface of the photoconductor was shaved and the surface of the photoconductor was deteriorated. On the other hand, when zinc stearate was applied at 0.0016 [mg / mm ² ], film thickness shaving on the surface of the photoreceptor did not occur and deterioration of the surface of the photoreceptor did not occur. When the coating amount is 0.0002 [mg / mm ² ], the coating amount is insufficient, and the surface deterioration of the photosensitive member, which becomes remarkable in the AC application discharge, cannot be suppressed. On the other hand, when the coating amount is 0.0016 [mg / mm ² ], it can be said that the coating amount for that purpose is satisfied.

  Here, the friction coefficient of the surface of the photoconductor was measured for the above two samples (by the Euler belt method). Immediately after the lubricant was applied to the surface of the photoconductor, the friction coefficient differs depending on the amount applied, but after a certain amount of time has passed. It was found that the friction coefficient was comparable. According to this experiment, the coefficient of friction became about 0.1 after a certain period of time. With such a low coefficient of friction, it is possible to prevent the film thickness from being removed on the surface of the photoreceptor due to mechanical wear.

A coating amount of 0.0002 [mg / mm ² ] is sufficient for applying zinc stearate as a lubricant to reduce the coefficient of friction on the surface of the photoreceptor, but the surface of the photoreceptor is notable for AC applied discharge. It can be seen that the coating amount needs to be larger than 0.0016 [mg / mm ² ] in order to protect from chemical deterioration. That is, the conditions for lowering the coefficient of friction of the photoconductor and the conditions for protecting the surface of the photoconductor from the chemical degradation that becomes noticeable in AC applied discharge are different. It can be seen that the conditions for protection cannot be derived from the prior art. According to the applicant's investigation, it is clear that the presence state of zinc stearate necessary for obtaining a low coefficient of friction action is different from the presence state of zinc stearate necessary for preventing deterioration of the photoreceptor surface due to electric discharge. Became.

[Experimental Example 4]
Next, the film thickness scraping amount on the surface of the photoreceptor, which becomes noticeable in the AC applied discharge, is the AC voltage peak-to-peak voltage value Vpp (hereinafter simply referred to as “Vpp”), that is, the amplitude value of the AC component applied to the charging member. An experimental example showing proportionality will be described.
The following experiment was performed using an apparatus including the photoconductor (8), the charging unit (2), and the lubricant applying unit (6) as shown in FIG. In order not to cause deterioration of the surface of the photosensitive member due to mechanical wear, all members in contact with the photosensitive member other than the charging roller (1) and the lubricant applying means (6) were removed in advance. Then, the Vpp was changed, and the film thickness scraping amount was measured when the surface of the photoreceptor was charged by alternating current discharge for 100 hours continuously. The experimental conditions are as follows.

(Experimental conditions)
Charging conditions:
Vpp (peak-to-peak voltage value of AC voltage) = 2.2, 2.6, 3.0 [kV]
f (frequency of AC voltage) = 1350 [Hz]
DC voltage value = −600 [V]
Movement speed of photoreceptor surface v = 113 [mm / s]
Protective substance: Zinc stearate Charging time: 100 hours

  As a result, it was found that the amount of film thickness scraping on the surface of the photoreceptor is proportional to Vpp. It was also found that the film thickness reduction amount was 0 when Vpp was about 1.9 [kV].

The present inventors consider this point as follows. It is known that when an AC voltage is applied, discharge does not start between the charging member surface and the photoreceptor surface unless the voltage applied to the charging member exceeds a predetermined value. According to the applicant's research, in the case of non-contact charging, when the closest distance between the charging member surface and the surface to be charged is Gp [μm], the voltage applied to the charging member is not less than the value shown in Formula 6. Then, discharge is started between the charging member surface and the photoreceptor surface. Hereinafter, this value is referred to as a discharge start voltage Vth.
[Equation 2]
Vth = 312 + 6.2 × (d / ε _opc + Gp / ε _air ) + √ (7737.6 × d / ε _opc )
Here, d is the film thickness [μm] of the photoreceptor, εopc is the relative permittivity of the photoreceptor, and εair is the relative permittivity of the space between the photoreceptor and the charging member.
When Vpp is equal to or greater than twice the above Vth, a bidirectional discharge occurs between the charging member and the photosensitive member.
In this experimental example, the gap between the charging roller and the photoconductor is 50 [μm], the relative permittivity of the photoconductor is about 3, the film thickness of the photoconductor is 30 [μm], and the space between the photoconductor and the charging means. Since the relative dielectric constant at is about 1, when these are applied to the above equation, Vth = 962 [V]. When the voltage applied to the charging means is 962 [V] or higher, discharge is started between the surface of the charging means and the surface of the photosensitive member, and when Vpp exceeds about 1924 [V], discharge by AC voltage is started. Conceivable. The dominant discharge phenomenon is a bidirectional discharge caused by an AC voltage. Therefore, when Vpp exceeds about 1.9 [kV], it is considered that the film thickness reduction of the photoreceptor starts.

[Experimental Example 5]
Next, a description will be given of an experimental example showing that the film thickness shaving amount on the surface of the photosensitive member, which is noticeable in AC applied discharge, is proportional to the frequency f of the AC voltage.
The basic configuration and experimental conditions of the apparatus used in this experimental example are the same as those in the experimental example 4, but the charging conditions and the moving speed of the photosensitive member surface are different from those in the experimental example 4. That is, in Experimental Example 4, the frequency f of the AC voltage is fixed and Vpp is changed, but in this experimental example, Vpp is fixed and the frequency f of the AC voltage is changed.

(Experimental conditions)
Charging conditions:
Vpp (peak-to-peak voltage value of AC voltage) = 2.2 [kV]
f (frequency of AC voltage) = 500, 900, 1400, 2000, 4000 [Hz] DC voltage value = −600 [V]
Moving speed of photoreceptor surface v = 104 [mm / s]
Lubricant: Zinc stearate Charging time: 100 hours

  As a result, it can be seen that the amount of film thickness reduction on the surface of the photoreceptor is proportional to the frequency f of the AC voltage.

  From the results of the present experimental example and the above experimental example 4, it has been clarified that the decrease in the thickness of the photosensitive member varies depending on the charging conditions (specifically, proportional to Vpp and f). Therefore, the present applicant has predicted that the reduction in the thickness of the photosensitive member has the following relationship. The validity of this prediction is confirmed by Experimental Example 6 to be described later, and in order to prevent chemical deterioration of the object to be charged, which becomes remarkable in the AC applied discharge by the charging means arranged in contact with or close to the object, The following knowledge about the amount of lubricant to be applied to the surface was obtained.

In the region where the object to be charged is charged by the charging means, the ratio of the number of elements of the specific element of the lubricant detected by XPS to the total number of elements of all the elements constituting the surface of the object to be charged detected by XPS [ %] Is set to the following number 1 or more, it becomes possible to prevent the surface of the charged object from being noticeably deteriorated in the AC applied discharge by the charging means arranged in contact or in proximity.
[Equation 1]
2,22 × 10 ⁻⁴ × {Vpp−2 × Vth} × f / v × Nα
Here, Vpp is the peak-to-peak voltage value [unit: V] of the AC voltage, f is the frequency of the AC component applied to the charging means [unit: Hz], and v is the moving speed of the surface of the object to be charged [unit: mm / mm. sec], Nα is the number of elements in one molecule of the specific element among the elements constituting the lubricant. Further, Vth is a discharge start voltage and is obtained by the above formula 2.

Further, the ratio of the number of elements constituting the lubricant detected by XPS to the total number of elements of all the elements constituting the surface to be charged detected by XPS in the region where the body to be charged is charged by the charging means. By setting B [%] to the following number 3 or more, the film thickness of the member to be charged can be prevented from being scraped.
[Equation 3]
2.22 × 10 ⁻⁴ × {Vpp−2 × Vth} × f / v × Nβ

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, the part here is a mass part.
In the examples, toners were prepared by changing the composition ratio of the toner materials, and the amount of wear of the image carrier when these toners were used was evaluated.

The toner used as a sample for the experiment was manufactured as follows.
[Toner A]
229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propion oxide 3-mole adduct, 208 parts of terephthalic acid, 46 parts of adipic acid and dibutyltin oxide 2 parts were added and reacted at 230 ° C. under normal pressure for 8 hours. Next, after reacting under reduced pressure of 10 to 15 mmHg for 5 hours, 44 parts of trimellitic anhydride was added to the reaction vessel and reacted at 180 ° C. for 2 hours under normal pressure to synthesize an unmodified polyester resin. .
The obtained unmodified polyester resin had a number average molecular weight of 2500, a weight average molecular weight of 6700, a glass transition temperature of 43 ° C., and an acid value of 25 mgKOH / g.
1200 parts of water, 540 parts of carbon black Printex 35 (manufactured by Dexa; DBP oil absorption = 42 ml / 100 mg, pH = 9.5) and 1200 parts of unmodified polyester resin were mixed using a Henschel mixer (manufactured by Mitsui Mining). . The resulting mixture was kneaded at 150 ° C. for 30 minutes using two rolls, then rolled and cooled, and pulverized with a pulverizer (manufactured by Hosokawa Micron Corporation) to prepare a master batch.
In a reaction vessel equipped with a stirrer and a thermometer, 378 parts of unmodified polyester resin, 110 parts of carnauba wax, 22 parts of salicylic acid metal complex E-84 (manufactured by Orient Chemical Co., Ltd.) and 947 parts of ethyl acetate were charged and stirred. The temperature was raised to 80 ° C., held at 80 ° C. for 5 hours, and then cooled to 30 ° C. over 1 hour. Next, 500 parts of a master batch and 500 parts of ethyl acetate were charged into the reaction vessel and mixed for 1 hour to obtain a raw material solution.
1324 parts of the obtained raw material solution was transferred to a reaction vessel, and filled with 80% by volume of 0.5 mm zirconia beads using a bead mill Ultra Visco Mill (manufactured by Imex Co., Ltd.). 3 passes under the condition of 6 m / sec. I. Pigment Red and carnauba wax were dispersed to obtain a wax dispersion.
Next, 1324 parts of a 65 wt% ethyl acetate solution of unmodified polyester resin was added to the wax dispersion. A layered inorganic mineral montmorillonite (Clayton APA Southern Clay modified at least partially with a quaternary ammonium salt having a benzyl group) was added to 200 parts of a dispersion obtained by one pass using Ultraviscomyl under the same conditions as above. 3 parts) (manufactured by Products) are added. K. The mixture was stirred for 30 minutes using a homodisper (manufactured by Tokushu Kika Kogyo Co., Ltd.) to obtain a toner material dispersion.

The viscosity of the obtained dispersion of toner material was measured as follows.
Using a parallel plate type rheometer AR2000 (made by D.A. Instruments Japan Co., Ltd.) equipped with a parallel plate with a diameter of 20 mm, the gap was set to 30 μm, and the toner material dispersion was at 25 ° C. After applying a shear force at a shear rate of 30000 seconds-1 for 30 seconds, the viscosity (viscosity A) when the shear rate was changed from 0 seconds-1 to 70 seconds-1 in 20 seconds was measured. Further, using a parallel plate rheometer AR2000, the viscosity (viscosity B) when a shearing force was applied to the dispersion liquid of the toner material at 25 ° C. at a shear rate of 30000 seconds-1 for 30 seconds was measured. The results are shown in Table 1.

In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, 22 parts of trimellitic anhydride And 2 parts of dibutyltin oxide were added and reacted at 230 ° C. for 8 hours under normal pressure. Next, it was made to react under reduced pressure of 10-15mHg for 5 hours, and the intermediate polyester resin was synthesize | combined.
The obtained intermediate polyester resin had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, a glass transition temperature of 55 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl value of 51 mgKOH / g.

Next, 410 parts of the intermediate polyester resin, 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are charged into a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. Was synthesized. The free isocyanate content of the obtained prepolymer was 1.53% by weight.
In a reaction vessel equipped with a stir bar and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to synthesize a ketimine compound. The amine value of the obtained ketimine compound was 418 mgKOH / g.
In a reaction vessel, 749 parts of a dispersion of toner material, 115 parts of a prepolymer and 2.9 parts of a ketimine compound are charged and mixed at 5,000 rpm for 1 minute using a TK homomixer (manufactured by Tokushu Kika). A mixture was obtained.
In a reaction vessel equipped with a stir bar and thermometer, 683 parts of water, 11 parts of reactive emulsifier (sodium salt of methacrylic acid ethylene oxide adduct) Eleminol RS-30 (manufactured by Sanyo Chemical Industries), styrene 83 Parts, 83 parts of methacrylic acid, 110 parts of butyl acrylate and 1 part of ammonium persulfate were stirred at 400 rpm for 15 minutes to obtain an emulsion. The emulsion was heated, heated to 75 ° C. and reacted for 5 hours. Next, 30 parts of a 1% by weight aqueous ammonium persulfate solution was added and aged at 75 ° C. for 5 hours to prepare a resin particle dispersion.

(Dispersion particle size and dispersion particle size distribution of toner material liquid)
In the present invention, “Microtrac UPA-150” (manufactured by Nikkiso Co., Ltd.) is used to measure the dispersoid particle size and dispersion particle size distribution of the toner material liquid, and analysis software “Microtrac Particle Size Analyzer-Ver. Analysis was performed using “10.1.2-016EE” (manufactured by Nikkiso Co., Ltd.). Specifically, the toner material liquid and then the solvent used for the toner material liquid preparation were added to a glass 30 ml sample bottle to prepare a 10 mass% dispersion. The obtained dispersion was subjected to a dispersion treatment for 2 minutes with an “ultrasonic wave disperser W-113MK-II” (manufactured by Honda Electronics Co., Ltd.).
After measuring the background with the solvent used for the toner material liquid to be measured, the dispersion was dropped, and the dispersed particle size was measured under the condition that the sample loading value of the measuring device was in the range of 1-10. In this measurement method, it is important to measure under the condition that the sample loading value of the measuring device is in the range of 1 to 10 from the viewpoint of measurement reproducibility of the dispersed particle size. In order to obtain the sample loading value, it is necessary to adjust the dripping amount of the dispersion.

Measurement and analysis conditions were set as follows.
Distribution display: volume, particle size classification selection: standard, number of channels: 44, measurement time: 60 sec, number of measurements: once, particle permeability: transmission, particle refractive index: 1.5, particle shape: non-spherical, density: The value of the solvent used for the toner material liquid among the values described in “Guidelines on Input Conditions at Measurement” published by Nikkiso Co., Ltd. was used as the value of 1 g / 3 cm ³ and the solvent refractive index.

990 parts of water, 83 parts of resin particle dispersion, 37 parts of a 48.5% by weight aqueous solution of dodecyl diphenyl ether disulfonate, Eleminol MON-7 (manufactured by Sanyo Kasei Kogyo Co., Ltd.), 1% by weight aqueous solution of sodium carboxymethylcellulose polymer dispersant 135 parts of BS-H-3 (Daiichi Kogyo Seiyaku Co., Ltd.) and 90 parts of ethyl acetate were mixed and stirred to obtain an aqueous medium.
To 1200 parts of the aqueous medium, 867 parts of the oil phase mixed liquid was added and mixed for 20 minutes at 13000 rpm using a TK homomixer to prepare a dispersion (emulsified slurry).
Next, the emulsified slurry was charged into a reaction vessel in which a stirrer and a thermometer were set, and after removing the solvent at 30 ° C. for 8 hours, aging was performed at 45 ° C. for 4 hours to obtain a dispersed slurry.

After filtering 100 parts of the dispersion slurry under reduced pressure, 100 parts of ion-exchanged water was added to the filter cake, followed by mixing at 12000 rpm for 10 minutes using a TK homomixer, followed by filtration.
To the obtained filter cake, 10 wt% hydrochloric acid was added to adjust the pH to 2.8, and the mixture was mixed at 12000 rpm for 10 minutes using a TK homomixer, followed by filtration.
Furthermore, 300 parts of ion-exchanged water was added to the obtained filter cake, mixed for 10 minutes at 12000 rpm using a TK homomixer, and then filtered twice to obtain a final filter cake.
The obtained final filter cake was dried at 45 ° C. for 48 hours using a circulating drier, sieved with a mesh opening of 75 μm, and hydrophobic silica 1 as an external additive was added to 100 parts of the obtained toner base particles. 0.0 part and 0.5 part of hydrophobized titanium oxide were added and mixed using a Henschel mixer (Mitsui Mining Co., Ltd.) to produce a toner.
Table 1 shows the physical properties of Toner A produced here.

[Toner B]
Toner B was produced in the same manner as Toner A, except that the amount of the modified layered inorganic mineral (trade name: Clayton APA) was changed from 3 parts to 0.1 part. Table 1 shows the physical properties of Toner B produced here.

[Toner C]
Toner C was produced in the same manner as Toner A, except that at least a part of Clayton APA was changed to layered inorganic mineral montmorillonite (Clayton HY Southern Clay Products) modified with an ammonium salt having a polyoxyethylene group. The physical properties of Toner C produced here are shown in Table 1.

[Toner D]
Toner D was produced in the same manner as Toner A, except that the amount of Kraton APA added was changed from 3 parts to 1.4 parts. Table 1 shows the physical properties of Toner D produced here.

[Toner E]
Toner F was produced in the same manner as Toner A, except that the amount of Clayton APA added was changed from 3 parts to 6 parts. Table 1 shows the physical properties of Toner E produced here.

[Toner F]
Toner F was prepared in the same manner as Toner A, except that Clayton APA was not added. Table 1 shows the physical properties of Toner F produced here.

[Toner G]
Toner G was produced in the same manner as toner A, except that the amount of Clayton APA added was changed from 3 parts to 10 parts. Table 1 shows the physical properties of Toner G produced here.

[Toner H]
Toner H was produced in the same manner as Toner A, except that Clayton APA (manufactured by Southern Clay Products) was changed to unmodified layered inorganic mineral montmorillonite (trade name: manufactured by Kunipia Kunimine Kogyo Co., Ltd.). Table 1 shows the physical properties of Toner H produced here.

[Toner I]
The modified layered inorganic mineral (trade name Kraton APA) was changed to organosilica sol (MEK-ST-UP, solid content concentration 20% by mass, average primary particle size 15 nm, manufactured by Nissan Chemical Industries, Ltd.), and the amount added was 20 parts. Toner I was produced in the same manner as Toner A except for the changes. Table 1 shows the physical properties of Toner I produced here.

(Examples 1-5 and Comparative Examples 1-4)
Using toners A to I produced by the above method, image formation was carried out under the following methods and conditions. As the image carrier used for image formation, the image carrier having a film thickness of 30 μm in which the filler is dispersed in the surface layer in the above text was used.
In this experiment, Imagio neo C600 was used, but there is a concern that the lubricant is not sufficiently applied in the state of a commercial product. Therefore, this time, in accordance with Embodiment 1 described in Japanese Patent Application Laid-Open No. 2005-17469, the Imagio neo C600 PCU was remodeled, and after the primary transfer, a cleaning blade was brought into contact with a solid lubricant formed in a bar shape of zinc stearate. The lubricant application brush and then the lubricant application blade were brought into contact with the image carrier, and the gap between the charging roller and the photoconductor was set to 50 μm.
Using the PCU modified in this way, it was first confirmed whether the lubricant was properly applied.
The image bearing member is brought into contact with a charging means, a cleaning blade, a zinc stearate bar, a lubricant application brush, and a lubricant application blade, and under the photosensitive member rotation conditions (moving speed of the photosensitive member surface of 300 mm / sec) for actual experiments. The photoconductor was rotated while charging only for 10 minutes (Vpp (AC voltage peak-to-peak voltage value [unit: V]) 2000 V, f (AC voltage AC frequency [unit: Hz]) 2200 Hz), and lubricant was applied. Applied. Thereafter, according to Japanese Patent Laid-Open No. 2005-17469, the zinc element contained in the protective material of the lubricant detected by XPS with respect to the total number of elements of all the elements constituting the outermost surface of the photoreceptor detected by XOS The element number ratio [%] was found to be 0.42, and the ratio of the number of elements constituting the lubricant detected by XPS to the total number of elements of all elements constituting the outermost surface of the photoreceptor [ %] Was 12.05.
On the other hand, when the right side value of Equation (1) and the right side value of Equation (3) were determined using the set values under the above experimental conditions, A = 0.28 and B = 11.15. The detected element ratio was a larger value, and it was confirmed that the lubricant could be applied to the photoreceptor sufficiently uniformly under the PCU and experimental conditions. (In the derivation of Vth in equation (2), since the relative permittivity of the photosensitive member was about 3, εopc was set to 3, and the relative permittivity in the gap between the charging means and the photosensitive member was about 1, so εair was Calculated as 1.)
From the above, the following experiment was performed using the modified PCU and the above experimental conditions. The evaluation results are shown in Table 1.

1. All sample toners and equipment used in the experiment are left in an environmental room at 25 ° C. and 50% for one day.
2. Solid lubrication using Imagio neo C600 modified PCU according to Embodiment 1 described in Japanese Patent Application Laid-Open No. 2005-17469, primary transfer and cleaning auxiliary brush, then cleaning blade, and then zinc stearate in bar shape The lubricant application brush contacted with the agent and then the lubricant application blade were in contact with the image carrier.
3. The elastic modulus of the cleaning blade was 70%, the thickness was 2 mm, and the contact angle of the counter with the image carrier was 20 °.
4). All the toner on the PCU is removed, leaving only the carrier in the developing device.
5. 28 g of black toner serving as a sample is put into a developing device having only a carrier, and 400 g of a developer having a toner concentration of 7% is prepared.
6). The modified PCU is mounted on the Imageo neo C600 main body, and only the developing device is spun for 5 minutes at a developing sleeve linear velocity of 300 mm / s.
7). Both the developing sleeve and the photoconductor were rotated at 300 mm / s trailing, and the developing bias was adjusted so that the toner on the photoconductor was 0.6 ± 0.05 mg / cm ² .
8). Under the above development conditions, the transfer current was adjusted so that the transfer rate was 96 ± 2%. Using the set value, the fine line image shown in FIG. 6 was output until an abnormal image estimated to be caused by the deteriorated lubricant was generated.
9. When the number of sheets when an abnormal image occurred reached the guaranteed number of sheets of the target image forming apparatus, the evaluation result was “◯”.
10. The above experiment was performed for each toner.

 The evaluation results are shown in Table 1. From these experimental results, it was revealed that in Examples 1 to 5 using the toner of the present invention, the deteriorated lubricant could be removed from the photoreceptor.

1 is a diagram illustrating an entire image forming apparatus. 1 is a diagram illustrating a main part of an image forming apparatus. 1 is a diagram illustrating an image forming apparatus using toner according to the present invention. It is a figure which shows the other image forming apparatus using the toner in this invention. It is a figure which shows the other image forming apparatus using the toner in this invention. It is a figure which shows the layer structure of an amorphous silicon photoconductor. It is a figure which shows a chart (thin line image).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Charging means 2 Exposure means 3 Developing means 4 Transfer means 5 Lubricant 6 Lubricant application means 7 Cleaning means 8 Image carrier 9 Paper feed means 10 Fixing means 11 Cleaning auxiliary means 12 Lubricant leveling means 500 Image carrier (electrons) Photoconductor)
501 Support 502 Photoconductive layer 503 Surface layer
504 Charge injection layer 505 Charge generation layer

Claims (11)

An image carrier, a charging unit that charges the surface of the image carrier by proximity or direct discharge, an exposure unit that writes a latent image by exposing on the image carrier, and a latent image written on the image carrier. In an image forming apparatus having a developing means for developing the toner and a transferring means for transferring the developed toner to an intermediate transfer body or printing paper,
The amount of lubricant applied to the image carrier is in the range represented by the following formulas 1 to 3,
The ratio of the number of elements A of the specific element of the lubricant detected by XPS to the total number of elements of all the elements constituting the outermost surface of the image carrier detected by an X-ray photoelectron spectrometer (XPS) %) Satisfies the following number 1,
[Equation 1]
A ≧ 1.52 × 10 ⁻⁴ × {Vpp−2 × Vth} × f / v × Nα
(Where Vpp is the AC voltage peak-to-peak voltage value [unit: V],
f is the frequency of the AC component applied to the image carrier [unit: Hz],
v is the moving speed of the image carrier surface [unit: mm / sec],
Nα is the number of elements in one molecule of a specific element among elements constituting the lubricant.
Vth is a discharge start voltage, and is obtained by the following equation (2). )
[Equation 2]
Vth = 312 + 6.2 × (d / εopc + Gp / εair) + √ (7737.6 × d / εopc)
(At this time, d is the film thickness of the image carrier [unit: μm],
εopc is the relative permittivity of the image carrier,
εair is the relative dielectric constant in the space between the image carrier and the charging means,
Gp is the closest distance [unit: μm] between the surface of the charging unit and the surface of the image carrier. )
Further, the ratio B (%) of the number of elements constituting the lubricant detected by XPS with respect to the total number of elements of all the elements constituting the outermost surface of the image carrier detected by XPS is the following number. Satisfy 3
[Equation 3]
B ≧ 1.52 × 10 ⁻⁴ × {Vpp−2 × Vth} × f / v × Nβ
(Here, Nβ: a value obtained by subtracting the number of hydrogen elements from the total number of elements constituting one molecule of the lubricating substance.)
(The lubricant is a fatty acid metal salt, the specific element is metal, the Nα is 1, and the Nβ is 41. The closest distance between the charging means and the image carrier is 1 to 100 [ μm]),
The toner used for developing the image bearing member by the developing means is an aqueous granulated toner, and at least a binder resin, a colorant, and at least a part of ions between layers are modified with organic ions. A toner containing a modified layered inorganic mineral and having a BET specific surface area of 2.5 to 7.0 (m ² / g),
An image forming apparatus characterized by that.  2. The image forming apparatus according to claim 1, wherein the modified layered inorganic mineral is obtained by modifying at least a part of a metal cation with an organic cation.   3. The toner according to claim 1, wherein a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is in the range of 1.00 to 1.40. The image forming apparatus described.   The image forming apparatus according to claim 1, wherein the toner includes 1 to 10% by number of particles having a size of 2 μm or less.   The image forming apparatus according to claim 1, wherein the toner is prepared by externally adding a plurality of inorganic fine particles.   The image forming apparatus according to claim 5, wherein the inorganic fine particles include at least silica and titanium. The image forming apparatus according to claim 1, wherein a cleaning unit is provided in a rotation direction of the image carrier and a lubricant application unit is provided on the downstream side.   A cleaning unit is provided in the rotation direction of the image carrier, and a lubricant application unit is provided on the downstream side, and a lubricant leveling unit is further provided on the downstream side of the lubricant application unit and on the upstream side of the charging unit. The image forming apparatus according to claim 1. The image forming apparatus according to claim 1, wherein the image carrier is a photosensitive member in which a filler is dispersed.   An organic photoreceptor having a surface layer reinforced with a filler, an organic photoreceptor using a crosslinkable charge transport material, or a surface layer reinforced with a filler and a crosslinkable charge transport material. The image forming apparatus according to claim 1, wherein the image forming apparatus is an organic photoreceptor using   The image forming apparatus according to claim 1, wherein the image carrier is an amorphous silicon photoconductor.

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