JP4481788B2 - Toner and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide toner which ensures less deterioration in image quality such as fog over a prolonged period of time even if high-speed printing is repeated, and which is excellent in environmental stability, and to provide an image forming method. <P>SOLUTION: The toner is obtained by externally adding a charge control agent (b) to toner particles comprising a binder resin, a colorant, a charge control agent (a) and a polymer having sulfur atoms, wherein the charge control agent (a) is a metal compound of an oxycarboxylic acid, the charge control agent (b) is a metal M compound of an oxycarboxylic acid, the polymer having sulfur atoms is a vinyl polymer containing a constitutional unit of formula (1), an amount of the charge control agent (b) present on the toner surface when the toner is alkali-washed is 0.007-1.000 part by mass (on the basis of the mass of the toner), and the toner has an average circularity of 0.955-0.995 and a standard deviation in circularity of &lt;0.045. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to an electrostatic image developing nonmagnetic toner and an image forming method used for developing an electrostatic latent image in electrophotography and electrostatic recording. More specifically, the present invention relates to a toner used in an image recording apparatus that can be used in a copying machine, a printer, a facsimile, a plotter, and the like, and an image forming method.

  Conventionally, a number of methods are known as electrophotographic methods. In general, an electric latent image is formed on an electrostatic image carrier (hereinafter also referred to as a photoreceptor) by various means using a photoconductive substance. Then, the latent image is developed with toner to make a visible image, and if necessary, the toner image is transferred to a transfer material such as paper, and then the toner image is fixed on the transfer material by heat, pressure, etc. To obtain a copy.

  As a method of visualizing an electric latent image with toner, a cascade development method, a magnetic brush development method, a pressure development method, a magnetic brush development method using a two-component developer composed of a carrier and a toner, a toner carrier is a photoreceptor. Non-contact one-component development method that causes toner to fly from the toner carrier to the photoreceptor without contact with the toner, contact one-component development method in which the toner carrier is pressed against the photoreceptor and the toner is transferred by an electric field, and a jumping method using magnetic toner Are also used.

  In recent years, the colorization of electrophotographic technology has progressed, and in the printer field, higher speed, high-definition images, and longer life are desired. The technological trend of printers is progressing in the direction of further miniaturization and simplification, and the non-magnetic one-component development system is matched as an optimal development system for these.

  Compared to the two-component development method, the one-component development method does not supply fresh toner, and the toner repeatedly circulates in the developing device, and the layer thickness during the process of uniformly coating the developer on the developer carrier Since the pressure stress due to the regulating member is repeatedly received, the toner performance with higher durability is required.

  When the toner deteriorates due to long-term use, background fogging caused by a decrease in the charge amount of the toner is one of the major problems. In electrophotography and electrostatic recording, it is a proposition to keep the toner charge amount stable. The decrease in charge amount not only causes background fogging, but also decreases dot reproducibility and transferability, resulting in initial image quality. It becomes difficult to maintain.

  On the other hand, when the toner is designed to increase the charge amount in fear of a decrease in the charge amount, the latent image is filled with a small amount of high charge amount toner, and as a result, the maximum density and gradation reproducibility are lost. In addition, since electrostatic aggregation and electrostatic repulsion between toners become remarkable in a highly charged toner, uniform coating on a toner carrier becomes difficult, and halftone image quality is impaired.

  Therefore, the amount of charge required for the toner in order to achieve stable image quality over a long period of time is a moderate amount that does not cause fogging and can reproduce sufficient density and gradation from the start of use until the toner is used up. It is required to be able to control within a certain range.

  Furthermore, as the demand for printers increases worldwide, it is necessary to design in consideration of every usage environment, and the environmental stability of toner charging ability is also a very important factor.

  As a toner that takes into account the charge stability required for the toners shown above, a toner that has improved charge rise performance and charge stability performance by using a charge control resin and a charge control agent in combination, and that is compatible with high-speed development systems has been proposed. (See Patent Document 1).

  However, when the present inventors evaluated and examined this toner with a single-component development type high-speed machine, the initial charge rising property in the durability test was good, but the fog in the latter half of the durability, particularly in a high temperature and high humidity environment, was much worse. I found out that

  There has also been proposed a toner in which a charge control resin is internally added and a charge control agent is externally added as a toner aiming at narrow charge control, high chargeability, and good charge maintenance (see Patent Document 2).

  The present inventors similarly evaluated and examined this toner with a single-component development type high-speed machine. The initial charging stability was good, but as the endurance test progressed, the charge rising property was impaired. As a result, the fog was on a worsening trend.

  Both Patent Document 1 and Patent Document 2 matched the two-component development method, but in order to guarantee the image quality with a long life for the one-component development method that requires more durable performance, especially for high-speed machines. It was found that further stabilization of charging was necessary.

  The method of externally adding a charge control agent is certainly an effective means in that a charging function is directly added to the toner surface that determines the charging behavior (see Patent Document 3).

  The above toner has the effect of compensating for the stress deterioration caused by the layer forming blade in the latter half of the endurance by externally adding a charge control agent. However, in the evaluation with a high speed machine, the deterioration of the toner surface layer is promoted, and the fog is deteriorated before the toner is used up. And reached life.

  In order to effectively utilize the external addition effect of the charge control agent, proposals have been made to devise external addition conditions to increase the adhesion of the charge control agent without damaging the toner particles (see Patent Documents 4 and 5).

  The present inventors also studied various external addition conditions according to the above-mentioned document, but if the external addition conditions are too weak, the charging performance effect disappears early, while if the external addition conditions are strong, the durability member contamination due to toner particle damage. There was a problem.

  In other words, it is difficult to satisfy the high-speed process satisfactorily with the non-magnetic one-component development method only by the external addition effect of the charge control agent, and it cannot be put into practical use unless the basic charging ability of the toner particles themselves is stabilized over a long period of time. all right.

Japanese Patent No. 2623684 JP-A-5-119513 JP-A-9-127720 JP 2002-268280 A JP 2003-140391 A

  An object of the present invention is to provide a toner and an image forming method that solve the above-mentioned problems of the prior art.

  That is, an object of the present invention is to provide a toner and an image forming method that are less likely to cause image quality deterioration such as fogging over a long period of time even when high-speed printing is repeated, and that are excellent in environmental stability.

  In addition, the object of the present invention is to combine a quick charge rising property and a quick uniform coating property on a toner carrier in any application output mode, that is, a low-speed process speed condition in a high-temperature and high-humidity environment. It is an object of the present invention to provide a toner and an image forming method that can function stably for a long time and after a large number of sheets are printed.

  As a result of intensive investigations on a toner that can achieve a high-definition image with a long life even at a high process speed, the present inventors have found that a polymer having a sulfur atom having a high chargeability and excellent environmental characteristics in the toner particles. In addition, by uniformly dispersing a charge control agent having excellent charge rise characteristics and electrostatically attaching a charge control agent having an additional specific structure to the surface of the toner particles, the anti-degradation characteristics corresponding to a high-speed process speed machine In addition, the present inventors have found a toner and an image forming method that are excellent in charge rising characteristics at a low process speed in a high temperature and high humidity environment.

The present invention includes toner particles having a binder resin, a colorant, a charge control agent (a) and a polymer having a sulfur atom, and a charge control agent (b) externally added to the toner particles. Non-magnetic toner,
The toner particles are obtained by a polymerization method using an aqueous phase,
The charge control agents (a) and (b) are metal compounds having a metal M selected from any of Al, Zn, Zr, Fe, and B of oxycarboxylic acids,
The polymer having a sulfur atom is a vinyl polymer containing the following general formula (1) of Mw = 20,000 to 50,000 as a structural unit,
The when the non-magnetic toner and alkali washing, determined by X-ray fluorescence loss of the charge control agent (b) derived from the metal (M), parts by weight of the charge control agent present on the toner surface (b) is, the 0.020 to 0.700 part with respect to 100 parts by mass of toner particles,
The total mass A (mg / g) of oxycarboxylic acid extracted from 1 g of the nonmagnetic toner with a 0.1 mol / L sodium hydroxide aqueous solution is 0.5 to 5.0 mg / g (toner mass basis). ,
When the developing machine is filled with the non-magnetic toner and the toner carrier is rotated at a peripheral speed of 135 mm / sec in an environment of 30 ° C. and 80%, the surface potential (i) of the non-magnetic toner after 10 seconds elapses. The surface potential (ii) of the non-magnetic toner after lapse of 60 seconds is -5 to -50 V, and (i / ii) is 0.5 to 1.3.
The non-magnetic toner has an average circularity of 0.955 to 0.995 and a circularity standard deviation of less than 0.045.

［式中、Ｒ₁は水素原子あるいはメチル基、Ｒ₂およびＲ₃は水素原子またはアルキル基を表わす。また、ｎは１〜１０の整数を意味し、Ｘ₁は、水素原子を表す。］

[Wherein R ₁ represents a hydrogen atom or a methyl group, and R ₂ and R ₃ represent a hydrogen atom or an alkyl group. Further, n represents represent an integer of 1 to 10, X ₁ represents a hydrogen atom. ]

Further, the present invention is an image forming method having a developing step of visualizing the electrostatic latent image by transferring toner to the electrostatic latent image carried on the image carrier by developing means,
The developing means includes a rotatable toner carrier that carries toner and is disposed opposite to the image carrier, and a toner regulating member that regulates the amount of toner on the toner carrier,
The toner is a non-magnetic toner having the above-described configuration .

  According to the present invention, a resin having a sulfur atom excellent in charging characteristics, which is extremely superior in durability deterioration, and a charge control agent having a specific complex structure excellent in charge rising property are used in combination, and the manufacturing technology is improved. By making full use of them and controlling the existence state of the toner particles, and adding a charge control agent with a specific structure to the toner particle surface, the degradation characteristics are fully compatible with high-speed process speed machines. A high-quality image with little fogging can be provided over a long period of time even when output is performed at a low process speed in a wet environment.

The toner of the present invention comprises toner particles having a binder resin, a colorant, a charge control agent (a) and a polymer having a sulfur atom, and a charge control agent (b) externally added to the toner particles. Non-magnetic toner,
The toner particles are obtained by a polymerization method using an aqueous phase,
The charge control agents (a) and (b) are metal compounds having a metal M selected from any of Al, Zn, Zr, Fe, and B of oxycarboxylic acids,
The polymer having a sulfur atom is a vinyl polymer containing the following general formula (1) of Mw = 20,000 to 50,000 as a structural unit,
The when the non-magnetic toner and alkali washing, determined by X-ray fluorescence loss of the charge control agent (b) derived from the metal (M), parts by weight of the charge control agent present on the toner surface (b) is, the 0.020 to 0.700 part with respect to 100 parts by mass of toner particles,
The total mass A (mg / g) of oxycarboxylic acid extracted from 1 g of the nonmagnetic toner with a 0.1 mol / L sodium hydroxide aqueous solution is 0.5 to 5.0 mg / g (toner mass basis). ,
When the developing machine is filled with the non-magnetic toner and the toner carrier is rotated at a peripheral speed of 135 mm / sec in an environment of 30 ° C. and 80%, the surface potential (i) of the non-magnetic toner after 10 seconds elapses. The surface potential (ii) of the non-magnetic toner after lapse of 60 seconds is -5 to -50 V, and (i / ii) is 0.5 to 1.3.
By satisfying the relationship that the non-magnetic toner has an average circularity of 0.955 to 0.995 and a circularity standard deviation of less than 0.045, the saturation charge amount and the saturation charge amount arrival time can be controlled well, and the electron It is possible to provide charging characteristics suitable for the photographic system.

［式中、Ｒ₁は水素原子あるいはメチル基、Ｒ₂およびＲ₃は水素原子またはアルキル基を表わす。また、ｎは１〜１０の整数を意味し、Ｘ₁は、水素原子を表す。］

[Wherein R ₁ represents a hydrogen atom or a methyl group, and R ₂ and R ₃ represent a hydrogen atom or an alkyl group. Further, n represents represent an integer of 1 to 10, X ₁ represents a hydrogen atom. ]

  As a result of intensive studies, the present inventors have made a polymer having a sulfonic acid group and a metal compound of oxycarboxylic acid coexist in the toner as described above, and a specific metal compound of oxycarboxylic acid is formed on the toner particle surface. By using externally added toner, high-resolution and high-definition images can be formed that are compatible with high-speed process speed machines, and various output modes after printing a large number of sheets, especially when outputting high-quality glossy images. It has been found that image degradation such as fog and halftone uniformity can be reduced even at low process speeds.

  According to the knowledge of the present inventors, as a characteristic property of a resin having excellent charging characteristics having acrylamide methylpropanesulfonic acid as a constituent monomer that is suitably compatible with a styrene acrylic binder resin, after printing a large number of sheets, Although there is a difficulty with respect to the rise of charge under adverse conditions such as after standing for a long period of time, there is no non-uniform charge distribution or polarization as seen with charge control agents, and both ground and inverted fog are sufficient. We found that there is an advantage and focused on this characteristic.

  Further, the present inventors have found that the oxycarboxylic acid complex having a specific central metal has no problem with respect to the saturation charge amount arrival time, although the fog characteristic at the time of durability deterioration is very poor.

  The above two components have fatal problems when used alone, but have succeeded in extracting the merits of the two components more effectively by precisely controlling the amount and state of presence in the toner. . This is achieved by utilizing the interaction of both components by using a suspension polymerization process without using a new dispersing aid or the like.

  Although it is not necessarily clear about these reasons, the two functions of the charge rising characteristics of the aromatic oxycarboxylic acid having a specific central metal and the deterioration resistance characteristics of the charged site of the polymer having a sulfonic acid group are expressed to the maximum. This is considered to be because the existence of the charged sites was achieved. In other words, it is possible to achieve the existence state of the charging site that can complement both the weak charge deterioration property of the aromatic oxycarboxylic acid having a specific central metal and the weak point of charge rising delay property of the polymer having a sulfonic acid group. It is thought that it was because of.

  The reason why the dispersion stability of the oil droplets in the aqueous system was improved during suspension polymerization even when a polymer having a sulfur atom was used is that aromatic oxycarboxylic acids having a specific metal are suspended by the action of polar groups. It tends to segregate in the vicinity of the surface of the oil droplet when it is cloudy, and it elutes into an aqueous medium depending on the pH. Therefore, it is considered to act suitably as a surfactant on the surface of the toner droplet. It is believed that the interaction with dissolved sulfonic acid groups promotes suitable droplet stability.

  Further, the toner of the present invention is required to externally add a charge control agent having a specific metal of oxycarboxylic acid to the toner particle surface described above. According to the study by the present inventors, it was found that when the durability test was performed at a high process speed, the toner deterioration was further promoted when compared at the same durability sheet number as compared with the case where the durability test was performed at a low process speed. . As the toner deteriorates, the saturated charge amount and the time to reach the saturated charge amount become noticeable, so that the required charge amount of the toner on the toner carrier is satisfied at the time of output at a low process speed such as the high-quality gloss mode. Will not be possible and the background fog will deteriorate. As a substance that effectively improves the durability, a specific metal compound of oxycarboxylic acid, which is the same as or similar to the charge control agent used in the production of the toner particles, is externally added to the toner particle surface, thereby exacerbating the above problem. It was found that it can be achieved.

  Although the reason why the above problem has been solved is not clear, the present inventors consider as follows.

  In general, in order to improve the charging performance of the toner, a method of externally adding a charge control agent to the outermost surface of toner particles that contributes most to the charging performance can be considered. However, since the toner in the developing device is subjected to repeated rubbing stress, the charge control agent is detached from the surface of the toner particles, so that the useful life of the toner does not last long. If the amount of charge control agent to be added is increased in anticipation of detachment, the contamination level of the contact charging member such as the toner layer thickness regulating blade and the toner carrier will be deteriorated, which will have an adverse effect such as fogging. The addition amount is naturally limited. In the toner of the present invention, the sulfonic acid group in the resin component having a sulfur atom used in the toner particle production process is extremely uniformly present on the outermost surface of the toner particle because the polymerization reaction is carried out in an aqueous system. By adding an oxycarboxylic acid containing a specific metal having an interaction such as a salt structure or a cluster structure to the outside, uniform and strong electrostatic adhesion can be achieved, and the improvement of charging ability can be achieved over a long period of time. It is thought to be due to being sustained for a long time.

  As the charge control agent (a) added internally to the toner particles according to the present invention and the charge control agent (b) added externally, a conventionally known metal complex of oxycarboxylic acid can be used. With respect to the charge control agent (b), the central metal is selected from boron, aluminum, zinc, zirconium, and iron from the viewpoint of the interaction with the polar group present on the toner particle surface and the stability of the complex structure. It is limited to what is. In particular, it is more preferable that the central metal is selected from aluminum, zinc and zirconium, which is advantageous in terms of durability and charge rise.

  As the oxycarboxylic acid which is a ligand component, compounds represented by the following general formulas (2) and (3) are preferably used from the viewpoint of charge imparting ability.

［上記式（２）中、（Ａ）は下記の群より選ばれ、Ｘ₁は、水素原子、ナトリウム原子、カリウム原子、アンモニウム又は脂肪族アンモニウムを示す。］

[In the above formula (2), (A) is selected from the following group, and X ₁ represents a hydrogen atom, sodium atom, potassium atom, ammonium or aliphatic ammonium. ]

［上記式（３）中、Ｘ₂は、水素原子、ナトリウム原子、カリウム原子、アンモニウム、又は脂肪族アンモニウムを示し、Ｒ₄は、Ｃ₁〜Ｃ₂₂のアルキル基又はアルケニル基、アリール基を示し、Ｒ₅は、水素原子、Ｃ₁〜Ｃ₂₂のアルキル基又はアルケニル基、アリール基、アルコキシ基を示す。］

[In the above formula (3), X ₂ represents a hydrogen atom, sodium atom, potassium atom, ammonium, or aliphatic ammonium, and R ₄ represents a C _{1 to} C ₂₂ alkyl group, alkenyl group, or aryl group. , R ₅ represents a hydrogen atom, a C ₁ -C ₂₂ alkyl group or alkenyl group, an aryl group, or an alkoxy group. ]

  Among the oxycarboxylic acids represented by the general formulas (2) and (3), those preferably used in the present invention are oxycarboxylic acids having an aromatic ring, and monoalkyl aromatic oxycarboxylic acids, or A dialkyl aromatic oxycarboxylic acid is mentioned. In particular, salicylic acid, di-tert-butylsalicylic acid and alkylsalicylic acid such as 5-tert-octylsalicylic acid, hydroxynaphthoic acid, benzylic acid, etc., in addition to excellent charge rise characteristics, are easy to disperse uniformly on the toner surface due to the production method. Therefore, it is preferably used in the present invention.

  In the toner of the present invention, the mass part of the charge control agent (a) present in the toner, which is obtained from the fluorescent X-ray dose of the metal (M2) derived from the charge control agent (a) detected after alkali cleaning, It is preferably 0.02 to 0.5 part (based on the mass of the toner). A more preferable range is 0.06 to 0.4 part.

  The charge control agent (a) added at the time of toner particle production has a complex structure broken by the influence of heat, pH, etc., or a ligand component that exhibits sublimation, because oxycarboxylic acid is extremely reduced during the toner particle production process. The abundance of the complex itself cannot be clarified. However, by measuring the fluorescent X-rays of the central metal (M2) present in the toner particles, the mass part converted from the calibration curve of the charge control agent (a) to the charge control agent (a) and the durability stability of the toner Therefore, it is more preferable to control the abundance of the charge control agent (a) determined by this measurement method within the above range rather than the number of added parts at the time of toner production.

  When the number of detected parts in terms of the charge control agent (a) calculated from the fluorescent X-ray of the central metal (M2) is less than 0.02 parts, the charge rising characteristics of the toner particles themselves in the deteriorated toner state in the latter half of the durability. Is inferior, the fog tends to deteriorate. In addition, a difference in charge amount due to a difference in environment increases, resulting in poor image quality.

  If the number of detected parts exceeds 0.5 parts, the charge balance as a toner will be lost, and it will be difficult to control the environment such as charging up in a low-humidity environment or drastically decreasing the amount of charge in a high-humidity environment, resulting in poor image quality. To do.

  The approximate addition amount of the charge control agent (a) that can suitably satisfy the above-described amount is achieved by adding 0.1 to 2 parts by mass per 100 parts by mass of the polymerizable monomer. More preferably, 0.2 to 1.5 parts by mass, and even more preferably 0.3 to 1.2 parts by mass can be added to reproduce the optimum existence state.

  In addition, it is preferable that the addition amount of the charge control agent (a) added internally is within the above range regardless of the addition amount of the charge control agent (b) added externally. As in the present invention, the toner particles are formed by a polymerization reaction in an aqueous medium, and are deposited on the surface of the toner particles by adjusting the pH of the aqueous system. Since the charge control agent (b) has different crystal states and existence states and different charge characteristics, it cannot be simply measured by the total amount of internal and external additions.

  On the other hand, the abundance of the charge control agent (b) satisfying the present invention is determined on the surface of the toner, which is determined by the X-ray fluorescence reduction of the metal (M) derived from the charge control agent (b) when the toner is washed with alkali. It is essential that the mass part of the charge control agent (b) present is in the range of 0.007 to 1.000 parts (toner mass standard). A more preferred range is from 0.010 to 0.900 part, and a most preferred range is from 0.020 to 0.700 part.

  In the present invention, the amount of the charge control agent (b) externally added to the surface of the toner particles is limited to the method determined by the above-described fluorescence X-ray reduction during alkali cleaning.

  Although the charge control agent (b) itself shows a stable structure, it is necessary to consider the destruction of the complex structure due to heat damage or the like in the external addition step and the sublimation of the ligand part. ) Is appropriate. Further, in the present invention, it is considered that the central metal (M) ion deviated from the complex structure interacts with the sulfonic acid ion cluster group present on the toner particle surface, and stabilization of charge control is achieved. Therefore, quantification with the central metal (M) is essential.

  In addition, since the charge control agent itself exhibits a very high charge amount, there may be an effect of large adhesion loss in each step of toner production such as external addition and sieving, and the addition amount and the detection amount are different.

  When the abundance of the charge control agent (b) obtained by the above measurement is less than 0.007 part, the charging characteristics of the toner are governed only by the charging characteristics of the toner particle matrix itself, and charging performance associated with durability Deterioration of can not be denied, can not withstand long life.

  On the other hand, when the amount of the charge control agent (b) exceeds 1.000 parts, a thin layer coat spot called blotch is noticeably generated due to an excessive saturation charge amount in a low-temperature and low-humidity environment. This causes the problem that the maximum concentration is lowered.

  The approximate addition amount of the charge control agent (b) that can suitably satisfy the abundance is 0.02 to 0.8 parts by mass, more preferably 0.025 to 0.7 parts by mass, per 100 parts by mass of the toner particles. This is achieved by adding part.

  In the present invention, the mass parts of the charge control agent (b) present on the toner surface and the charge control agent (a) present inside the toner particles are determined by the following method.

  Prepare 100 ml of 0.1N aqueous sodium hydroxide solution containing 0.08 g of Contaminone as a dispersant, weigh 4 g of toner, add it, and stir for 30 minutes to completely dissolve the charge control agent present on the toner surface. . Subsequently, the mixture is filtered using 5C filter paper (manufactured by Advantech), and 100 ml of a 0.1N sodium hydroxide aqueous solution is further added to carefully wash off the toner surface. The filtered sample was dried at 40 ° C. for 24 hours using a vacuum dryer, and the toner was washed with alkali to obtain a toner.

The toner and the toner after alkali washing are each made into pellets having a diameter of 40 mm by a tablet molding machine at a pressure of 159 N / mm ² , and using a wavelength dispersive X-ray fluorescence analyzer RIX3000 (manufactured by Rigaku Corporation), The peak intensity of the central metal (M2) of the charge control agent (a) and the central metal (M) of the charge control agent (b) is measured.

  Using the calibration curves of the charge control agent (a) and the charge control agent (b) measured in advance, the amount of the charge control agent (b) added externally is the peak intensity of the central metal (M) of the toner. From the value obtained by subtracting the peak intensity of the central metal (M) of the toner after alkali cleaning, the toner-based mass part was determined.

  The abundance of the charge control agent (a) in the toner particles was determined based on the toner-based mass part from the peak intensity of the central metal (M2) of the toner after alkali cleaning.

  In the toner of the present invention, the presence state of the two types of charge control agents (a) and (b) on the toner surface, which determines the charge rising characteristics, is defined by a quantitative value of oxycarboxylic acid using an alkali extraction method. can do.

  That is, in addition to the conversion value of the charge control agent amount obtained by determining the central metal for each of the charge control agents described above, by defining the amount of oxycarboxylic acid on the toner surface, the charge control agents (a) and ( The presence state in the toner of b) can be controlled to a higher degree, and charging stability under more severe conditions can be guaranteed.

  The total mass A (mg / g) of oxycarboxylic acid extracted from 1 g of the toner of the present invention with a 0.1 mol / L sodium hydroxide aqueous solution is within the range of A = 0.5 to 7.0 mg / g. Preferably there is. A more preferable range is A = 0.7 to 5.0 mg / g.

  When the mass A of the oxycarboxylic acid is less than 0.5 mg / g, as the durability deterioration progresses, the charging characteristics of the toner are governed only by the resin having a sulfur atom, the charge rising property is remarkably inferior, and the durability Fog worsens in the second half.

  When the mass A of the oxycarboxylic acid exceeds 7 mg / g, the amount of the charge control agent on the toner particle surface is excessive, and with the endurance, the ability to impart tribo to the toner due to the contamination of the charging member decreases, and fogging occurs. Deteriorating tendency.

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

  That is, 50 ml of a 0.1 mol / liter aqueous sodium hydroxide solution containing 0.04 g of contamination is added as a dispersing agent, 1 g of toner is weighed and added, and stirred at 50 rpm using a stirrer to uniformly disperse. After carrying out the dispersion treatment for 30 minutes, filtration is performed using 5C filter paper (manufactured by Advantech), and the absorbance of the obtained filtrate is measured. By using a predetermined calibration curve from the obtained results, the mass A (mg) of oxycarboxylic acid extracted from 1 g of toner with a 0.1 mol / liter sodium hydroxide aqueous solution can be obtained.

  The polymer having a sulfur atom of the present invention has the following general formula (1).

［式中、Ｒ₁は水素原子あるいはメチル基、Ｒ₂およびＲ₃は水素原子またはアルキル基を表わす。また、ｎは１〜１０の整数を意味し、Ｘ₁は、水素原子を表す。］

[Wherein R ₁ represents a hydrogen atom or a methyl group, and R ₂ and R ₃ represent a hydrogen atom or an alkyl group. Further, n represents represent an integer of 1 to 10, X ₁ represents a hydrogen atom. ]

As a sulfur-containing monomer for producing a polymer having a sulfur atom, 2-acrylamido-2-methylpropanesulfonic acid, 2-methacrylamide-2-methylpropanesulfonic acid, and the like are preferable. The monomer is not limited to these as long as it satisfies the formula (1). For example, the following formula X (SO ₃ ⁻ ) n · mY ^{k +}
(X represents a polymer moiety derived from the polymerizable monomer, Y ⁺ represents a counter ion, k is a valence of the counter ion, m and n are integers, and n = k × m. is there.)
The thing which has the following structures is mentioned. The counter ions are preferably hydrogen ions, sodium ions, potassium ions, calcium ions, ammonium ions and the like.

  The resin having a sulfur atom according to the present invention may be a homopolymer of the above monomer, or may be a copolymer of the above monomer and another monomer. As a monomer that forms a copolymer with the above monomer, there is a vinyl polymerizable monomer, and a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used.

  Monofunctional polymerizable monomers include styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butyl. Styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p -Styrene derivatives such as phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2 -Ethylhexyl acrylate , Acrylic polymerizable monomers such as n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl Methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate Methacrylic polymerizable monomers such as dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl formate; vinyl methyl ether Vinyl ether such as vinyl ethyl ether and vinyl isobutyl ether; vinyl ketone such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.

  As polyfunctional polymerizable monomers, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol Diacrylate, polypropylene glycol diacrylate, 2,2′-bis (4- (acryloxydiethoxy) phenyl) propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol Dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol Dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis (4- (methacryloxy-diethoxy) phenyl) propane, 2,2′-bis (4-methacryloxy / polyethoxy) phenyl) propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, divinyl ether, and the like.

  As the resin having a sulfur atom, a monomer as described above can be used, but it is more preferable that the resin contains a styrene derivative.

  There are bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, ionic polymerization and the like as a method for producing a resin having a sulfur atom, but solution polymerization is preferable from the viewpoint of operability.

  In the resin having a sulfur atom, the acid value (mgKOH / g) of the polymer having a sulfonic acid group is preferably 3 to 50. More preferably, it is 5 to 40.

  When the acid value is less than 3, sufficient charge control action as mentioned in the present invention cannot be obtained, and environmental characteristics are poor because it is governed by the charging ability of only the metal complex of oxycarboxylic acid. When the acid value exceeds 50, when particles are produced by suspension polymerization using a composition containing such a polymer, the toner particles have an irregular shape and the circularity is reduced. As a result, durability characteristics are inferior.

  As for the molecular weight of the resin having a sulfur atom according to the present invention, the weight average molecular weight (Mw) is in the range of 20,000 to 50,000. More preferably, 27000-45000 is good. When the weight average molecular weight (Mw) is less than 20000, segregation on the outermost surface of the toner particles becomes remarkable, and charge-up tends to be caused in a low temperature and low humidity environment. If it exceeds 50,000, it takes a long time to dissolve in the monomer and, in addition, results in a decrease in the dispersibility of other functional materials when forming toner particles.

  The glass transition point (Tg) of the resin having a sulfur atom is preferably 50 ° C to 100 ° C. When the glass transition point is less than 50 ° C., the fluidity and storage stability of the toner are inferior, and the development characteristics are also inferior. When the glass transition point exceeds 100 ° C., the fixability at the time of an image having a high toner printing rate is poor.

  In addition, the measurement of the glass transition temperature (Tg) of resin which has a sulfur atom uses DSC-7 by Perkin Elmer, for example. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium. An aluminum pan is used as a measurement sample, an empty pan is set as a control, and measurement is performed at a heating rate of 10 ° C./min.

  As the definition of Tg, from the DSC curve at the time of the second temperature increase, the intersection of the base line before the endothermic peak and the base line after the endothermic peak and the rising curve is defined as Tg.

  The volatile content of the resin having sulfur atoms is preferably 0.01% to 2.0%. In order to reduce the volatile content to less than 0.01%, the volatile content removal process becomes complicated, and when the volatile content exceeds 2.0%, charging under high temperature and high humidity, especially charging after standing. It becomes inferior. The polymer volatile content is the ratio of the weight that decreases when heated at high temperature (135 ° C.) for 1 hour.

  The extraction of the resin having a sulfur atom from the toner is not particularly limited, and any method can be used.

  In the toner of the present invention, the ratio (S / C) of atomic number% (S) of sulfur element to atomic number% (C) of carbon element present on the toner surface measured by X-ray photoelectron spectroscopy is 0.0005. It is desirable to be within the range of ~ 0.0050. A more preferable range is 0.001 to 0.004.

  When (S / C) is less than 0.0005, the amount of sulfonic acid groups present on the surface of the toner particles is small, the amount of charge as toner particles is reduced, and the charge control agent (b) added externally Because it cannot be expected to interact with the battery, the deterioration of charging performance due to durability cannot be denied.

  On the other hand, when (S / C) exceeds 0.0050, due to excessive saturation charge in a low-temperature and low-humidity environment, thin coat spots called blotches are noticeably generated, and halftone reproducibility and maximum density decrease. Cause problems.

The composition analysis of the toner surface by ESCA (X-ray photoelectron spectroscopic analysis) can be measured under the following conditions.
Equipment used: 1600S type X-ray photoelectron spectrometer manufactured by PHI Measurement conditions: X-ray source MgKα (400 W)
Spectral region 800μmφ

  In the present invention, the surface atomic concentration was calculated from the measured peak intensity of each element using a relative sensitivity factor provided by PHI. Specifically, when the content ratio of the sulfur element is obtained, the sulfur element having a peak top at a binding energy of 166 to 172 eV with respect to the content (C) of the carbon element present on the toner surface measured by X-ray photoelectron spectroscopy analysis. The ratio (S / C) of the content (S) was determined.

  When the toner is obtained by synthesizing the present invention by the suspension polymerization method, the amount of the sulfur atom-containing resin is preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of the binder resin. A more preferable range is 0.2 to 1.5 parts by mass.

  When the amount of the resin having a sulfur atom added is less than 0.1 parts by mass, the toner surface existing amount of the sulfonic acid group as a charging site is insufficient, and the effect of stabilizing the charge distribution cannot be obtained.

On the other hand, when it exceeds 2 parts by mass, the droplet stability is deteriorated in the granulation step, the average circular shape degree and particle size distribution is disturbed.

  The content of the resin having a sulfur atom in the toner can be measured using a capillary electrophoresis method or the like.

  The average circularity and circularity standard deviation, which are essential conditions for the toner of the present invention, will be described below.

The toner of the present invention, the essential der average circularity is 0.955 or more 0.995 or less is, preferably Ru der 0.970 or 0.995 or less. Since the toner having an average circularity of 0.955 or more has few edge portions on the surface, it is difficult for the charge to localize within one particle, and the charge amount distribution tends to be sharp. Developed faithfully. In addition, since the agitation and rubbing stress in the developing device also increase in the durability at a high process speed, the toner having an average circularity of less than 0.955 is deteriorated in toner charging ability due to the scraping of the edge portion of the surface. It is promoted and fogging worsens.

  On the other hand, toner having an average circularity exceeding 0.995 is not preferable because the circularity is very high and there is a concern about poor cleaning.

  Furthermore, the toner of the present invention has a sharp charge distribution by making the circularity standard deviation of the circularity frequency distribution of the toner particles less than 0.045, preferably less than 0.035, and dot reproduction at high process speeds. Excellent in properties.

  When the circularity standard deviation is 0.045 or more, the charge distribution tends to widen and the latitude such as fog becomes narrow.

  The average circularity in the present invention is used as a simple method for quantitatively expressing the shape of the particles. In the present invention, the average circularity is measured using a flow type particle image analyzer “FPIA-1000” manufactured by Toa Medical Electronics. The circularity degree (ai) of each particle measured for a particle group having a circle-equivalent diameter of 3 μm or more was determined by the following equation (1), and the total particle size measured by the following equation (2) A value obtained by dividing the sum of the circularity by the total number of particles (m) is defined as the average circularity (a).

  In addition, “FPIA-1000”, which is a measuring apparatus used in the present invention, calculates the circularity of each particle, and then calculates the average circularity. A calculation method is used in which 1.00 is divided into 61 classes and the average circularity is calculated using the center value and frequency of the dividing points. However, the error from each value of the average circularity calculated by this calculation formula is very small and is substantially negligible. In the present invention, the calculation time can be shortened and the calculation formula For reasons of handling data such as simplification, such a calculation formula partially modified by using the concept of the calculation formula that directly uses the circularity of each particle described above may be used.

  Measuring means are as follows. A dispersion is prepared by dispersing 5 mg of the developer in 10 ml of water in which about 0.1 mg of the surfactant is dissolved, and the dispersion is irradiated with ultrasonic waves (20 KHz, 50 W) for 5 minutes. Measurement is performed with the above apparatus at 20,000 particles / μl, and the average circularity of a particle group having a circle-equivalent diameter of 3 μm or more is determined.

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

  In this measurement, the reason why the circularity is measured only for the particle group having an equivalent circle diameter of 3 μm or more is that the particle group of the external additive existing independently of the toner particles in the particle group having an equivalent circle diameter of less than 3 μm. This is because the circularity of the toner particle group cannot be accurately estimated due to the influence of such a large amount.

  Next, the particle size of the toner will be described.

  The toner of the present invention preferably has a weight average diameter of 3 μm to 10 μm in order to develop a finer latent image dot faithfully for higher image quality. The weight average diameter of the toner is more preferably 4 μm to 8 μm. In a toner having a weight average diameter of less than 3 μm, fluidity and agitation as a powder are lowered, and it becomes difficult to uniformly charge individual toner particles. This is not preferable for the toner used in the present invention. When the weight average diameter of the toner exceeds 10 μm, the characters and the line image are likely to be scattered, and high resolution is difficult to obtain. Further, as the apparatus becomes higher in resolution, the dot reproduction of toner of 8 μm or more tends to deteriorate.

  The weight average particle diameter and number average particle diameter of the toner of the present invention can be measured by various methods such as Coulter Counter TA-II type or Coulter Multisizer (manufactured by Coulter Inc.). Specifically, it can be measured as follows. Using Coulter Multisizer (manufactured by Coulter), an interface (manufactured by Nikka) and a PC9801 personal computer (manufactured by NEC) that output number distribution and volume distribution are connected, and the electrolyte is 1% NaCl using first grade sodium chloride. Adjust the aqueous solution. For example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used. The measurement procedure is as follows. 100 to 150 ml of the electrolytic aqueous solution is added, and 2 to 20 mg of a measurement sample is further added. The electrolyte in which the sample is suspended is dispersed for about 1 to 3 minutes with an ultrasonic disperser, and the volume and number distribution of toner particles of 2 μm or more are measured by using the aperture with the Coulter Multisizer. And calculate. Then, the volume-based weight average particle diameter (D4) obtained from the volume distribution according to the present invention and the number-based average particle diameter obtained from the number distribution, that is, the number average particle diameter (D1) are obtained.

  The toner particles of the present invention are preferably particles obtained by a polymerization method using an aqueous phase. By polymerizing the toner particles in an aqueous system, the sulfonic acid group-containing resin and the charge control agent (a), which are essential components of the present invention, are easily distributed uniformly on the surface of the toner particles. It becomes possible to control the existence state of the charge site in the toner including the interaction between the group and the externally added charge control agent (b) more precisely.

  Methods for polymerizing toner particles in an aqueous system include suspension polymerization method, emulsion polymerization method, emulsion association polymerization method, seed polymerization method, etc. Among them, it is said that the balance between particle size and particle shape is easy to balance. In this respect, it is particularly preferable to produce the suspension by a suspension polymerization method. In this suspension polymerization method, a monomer composition is prepared by uniformly dissolving or dispersing a polymerizable monomer and a colorant (and, if necessary, a polymerization initiator, a crosslinking agent, a charge control agent, and other additives). After that, this monomer composition is dispersed in a continuous layer (aqueous phase) containing a dispersion stabilizer using a suitable stirrer, and simultaneously subjected to a polymerization reaction to obtain a toner having a desired particle size. Is. The toner obtained by this suspension polymerization method (hereinafter, polymerized toner) has toner particles satisfying the physical property requirement that the average circularity is 0.955 to 0.995 or more because individual toner particle shapes are almost spherical. Further, such toners have high development characteristics because the distribution of charge amount is relatively uniform.

  The toner according to the present invention can also be produced by a pulverization method. However, toner particles obtained by this pulverization method are generally amorphous, and the average circularity which is a preferable requirement of the present invention is 0.955. In order to obtain a physical property of ˜0.995, it is necessary to perform mechanical / thermal or some special treatment.

  The toner of the present invention preferably contains 0.5 to 50 parts by weight of a release agent with respect to 100 parts by weight of the binder resin. Examples of the binder resin include various waxes as will be described later.

  The toner image transferred onto the transfer material is then fixed on the transfer material with energy such as heat and pressure to obtain a semi-permanent image. At this time, heat roll type fixing and film type fixing are generally used.

  As described above, if toner particles having a weight average particle size of 10 μm or less can be used, a very high-definition image can be obtained. However, toner particles having a small particle size can be obtained when a transfer material such as paper is used. It enters into the gaps between the fibers, and heat reception from the heat fixing roller becomes insufficient, so that low temperature offset is likely to occur. However, in the toner according to the present invention, by including an appropriate amount of the release agent, it is possible to achieve both high resolution and offset resistance.

  As the release agent usable for the toner according to the present invention, petroleum wax such as paraffin wax, microcrystalline wax, petrolactam and derivatives thereof, montan wax and derivatives thereof, hydrocarbon wax and derivatives thereof by Fischer-Tropsch method, Polyolefin waxes represented by polyethylene and derivatives thereof, natural waxes such as carnauba wax and candelilla wax, and derivatives thereof. These derivatives include oxides, block copolymers with vinyl monomers, and graft modified products. Furthermore, higher fatty alcohols, fatty acids such as stearic acid and palmitic acid, or compounds thereof, acid amide waxes, ester waxes, ketones, hydrogenated castor oil and derivatives thereof, plant waxes, animal waxes and the like can be mentioned. Among these waxes, those having an endothermic peak in a differential thermal analysis of 40 ° C. to 110 ° C. are preferred, and those having a temperature of 45 ° C. to 90 ° C. are more preferred.

  As content when using a mold release agent, the range of 0.5-50 mass parts is preferable with respect to 100 mass parts of binder resin. If the content is less than 0.5 parts by mass, the effect of suppressing the low temperature offset is poor, and if it exceeds 50 parts by mass, the long-term storage stability is deteriorated and the dispersibility of other toner materials is deteriorated, and the toner fluidity is deteriorated. Leading to deterioration and deterioration of image characteristics.

  The maximum endothermic peak temperature of the wax component is measured according to “ASTM D 3418-8”. For the measurement, for example, DSC-7 manufactured by PerkinElmer is used. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium. An aluminum pan is used as a measurement sample, an empty pan is set as a control, and measurement is performed at a heating rate of 10 ° C./min.

  The toner of the present invention contains a colorant as an essential component in order to impart coloring power. Examples of the organic pigment or dye preferably used in the present invention include the following.

  As the organic pigment or organic dye as the cyan colorant, a copper phthalocyanine compound and a derivative thereof, an anthraquinone compound, a basic dye lake compound, or the like can be used. Specifically, C.I. I. Pigment blue 1, C.I. I. Pigment blue 7, C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 1, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. Pigment blue 60, C.I. I. Pigment blue 62, C.I. I. And CI Pigment Blue 66.

  As organic pigments or dyes as magenta colorants, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds are used. . Specifically, C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I. Pigment red 7, C.I. I. Pigment violet 19, C.I. I. Pigment red 23, C.I. I. Pigment red 48: 2, C.I. I. Pigment red 48: 3, C.I. I. Pigment red 48: 4, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 81: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 144, C.I. I. Pigment red 146, C.I. I. Pigment red 150, C.I. I. Pigment red 166, C.I. I. Pigment red 169, C.I. I. Pigment red 177, C.I. I. Pigment red 184, C.I. I. Pigment red 185, C.I. I. Pigment red 202, C.I. I. Pigment red 206, C.I. I. Pigment red 220, C.I. I. Pigment red 221, C.I. I. And CI Pigment Red 254.

  As the organic pigment or organic dye as the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 62, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 83, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 95, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 109, C.I. I. Pigment yellow 110, C.I. I. Pigment yellow 111, C.I. I. Pigment yellow 120, C.I. I. Pigment yellow 127, C.I. I. Pigment yellow 128, C.I. I. Pigment yellow 129, C.I. I. Pigment yellow 147, C.I. I. Pigment yellow 151, C.I. I. Pigment yellow 154, C.I. I. Pigment yellow 168, C.I. I. Pigment yellow 174, C.I. I. Pigment yellow 175, C.I. I. Pigment yellow 176, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 181, C.I. I. Pigment yellow 191, C.I. I. And CI Pigment Yellow 194.

  These colorants can be used alone or mixed and further used in the form of a solid solution. The colorant used in the toner of the present invention is selected from the viewpoints of hue angle, saturation, brightness, light resistance, OHP transparency, and dispersibility in the toner.

  The colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.

  As the black colorant, carbon black, a magnetic material, and a color toned to black using the yellow / magenta / cyan colorant are used.

  In the present invention, when a toner is obtained using a polymerization method, it is necessary to pay attention to the polymerization inhibitory property and water phase transfer property of the colorant, and preferably a material that does not inhibit surface modification, for example, polymerization inhibition. It is better to apply a hydrophobizing treatment. In particular, dyes and carbon blacks have many polymerization inhibiting properties, so care must be taken when using them. A preferable method for surface-treating the dye system includes a method in which a polymerizable monomer is polymerized in the presence of these dyes in advance, and the obtained colored polymer is added to the monomer system.

  Carbon black may be treated with a substance that reacts with the surface functional groups of carbon black, such as polyorganosiloxane, in addition to the same treatment as the above dye.

  The toner of the present invention may contain a charge control agent as a third component in order to stabilize the charge characteristics. As the charge control agent, a known one can be used, and a charge control agent that has a high charging speed and can stably maintain a constant charge amount is particularly preferable. Further, when the toner is produced using a direct polymerization method, a charge control agent having a low polymerization inhibitory property and substantially free from a solubilized product in an aqueous dispersion medium is particularly preferable. However, addition of a charge control agent is not essential for the toner of the present invention, and the third charge is not necessarily contained in the toner by actively utilizing frictional charging with the toner layer thickness regulating member or the toner carrier. It is not necessary to include a control agent.

  Next, a method for producing the toner of the present invention by suspension polymerization will be described.

  When the toner of the present invention is produced by the suspension polymerization method, examples of the polymerizable monomer constituting the polymerizable monomer system to be used include the following.

  Examples of the polymerizable monomer include styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-ethylstyrene, methyl acrylate, ethyl acrylate, Acrylic esters such as n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, etc. , Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, Methacrylic acid dimethyl aminoethyl methacrylate esters such as diethylaminoethyl methacrylate and other acrylonitrile-methacrylonitrile-monomer acrylamide.

  These monomers can be used alone or in combination. Among the above-mentioned monomers, styrene or a styrene derivative is preferably used alone or mixed with other monomers from the viewpoint of the developing characteristics and durability of the toner.

  In the production of the polymerized toner according to the present invention, a resin may be added to the monomer system for polymerization.

  For example, a monomer containing a hydrophilic functional group such as an amino group, a carboxylic acid group, a hydroxyl group, a glycidyl group, or a nitrile group that cannot be used because it is soluble in an aqueous suspension and causes emulsion polymerization by dissolving in an aqueous suspension. When it is desired to introduce a body component into the toner, a random copolymer of these with a vinyl compound such as styrene or ethylene, a block copolymer, a graft copolymer, or the like, or in the form of a copolymer, or polyester, polyamide, etc. It can be used in the form of a polyaddition polymer such as a polycondensate, a polyether or a polyimine. When such a polymer containing a polar functional group is allowed to coexist in the toner, the above-mentioned wax component is phase-separated and the encapsulation becomes stronger, and a toner having good offset resistance, blocking resistance, and low-temperature fixability can be obtained. Obtainable.

  In addition, resins other than those described above may be added to the monomer system for the purpose of improving the dispersibility and fixing properties of the material or image characteristics. Examples of the resin used include styrene such as polystyrene and polyvinyltoluene. And styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, Styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-methacrylic acid Acid butyl copolymer, styrene-dimethylaminoethyl methacrylate copolymer Polymer, Styrene-vinyl methyl ether copolymer, Styrene-vinyl ethyl ether copolymer, Styrene-vinyl methyl ketone copolymer, Styrene-butadiene copolymer, Styrene-isoprene copolymer, Styrene-maleic acid copolymer Styrene copolymers such as styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacryl Acid resins, rosins, modified rosins, terpene resins, phenol resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins and the like can be used alone or in combination.

  As addition amount of these resin, 1-20 mass parts is preferable with respect to 100 mass parts of monomers. If the amount is less than 1 part by mass, the effect of addition is small.

  Furthermore, if a polymer having a molecular weight different from the molecular weight range of the toner obtained by polymerizing the monomer is dissolved in the monomer and polymerized, a toner having a wide molecular weight distribution and high offset resistance can be obtained. it can.

  The polymerization initiator used in the production of the polymerized toner according to the present invention has a half-life of 0.5 to 30 hours at the time of the polymerization reaction, and 0.5 to 20 mass per 100 mass parts of the polymerizable monomer. When the polymerization reaction is carried out with a part addition amount, a polymer having a maximum between 10,000 and 100,000 in molecular weight can be obtained, and the toner can be provided with desirable strength and suitable melting characteristics. Examples of polymerization initiators include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile) Azo or diazo polymerization initiators such as 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile; benzoyl peroxide, t-butylperoxy 2-ethylhexa Noate, t-butyl peroxypivalate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl Peroxide polymerization such as peroxide and lauroyl peroxide Agents.

  When the polymerized toner according to the present invention is produced, a crosslinking agent may be added, and a preferable addition amount is 0.001 to 15% by mass.

  In producing the polymerized toner according to the present invention, a molecular weight modifier can be used. Examples of the molecular weight modifier include mercaptans such as t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan; halogenated hydrocarbons such as carbon tetrachloride and carbon tetrabromide; α-methylstyrene dimer, and the like. Can be mentioned. These molecular weight regulators can be added before the polymerization starts or during the polymerization. The molecular weight modifier is usually used in a proportion of 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  In the method for producing a polymerized toner according to the present invention, generally, the above-described toner composition, that is, a polymer having a sulfonic acid group in a polymerizable monomer, a release agent, a plasticizer, a charge control agent, a crosslinking agent, The components necessary for the toner, such as colorants, and other additives such as an organic solvent, a high molecular weight polymer, and a dispersant added to reduce the viscosity of the polymer produced by the polymerization reaction are appropriately added, and the homogenizer, ball mill The monomer system uniformly dissolved or dispersed by a dispersing machine such as a colloid mill or an ultrasonic dispersing machine is suspended in an aqueous medium containing a dispersion stabilizer. At this time, the particle size of the obtained toner particles becomes sharper by using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser to obtain a desired toner particle size at a stretch. The polymerization initiator may be added at the same time when other additives are added to the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. Also, a polymerization initiator dissolved in a polymerizable monomer or solvent can be added immediately after granulation and before starting the polymerization reaction.

  After granulation, stirring may be performed using a normal stirrer to such an extent that the particle state is maintained and the particles are prevented from floating and settling.

  In the production of the polymerized toner according to the present invention, known surfactants and organic or inorganic dispersants can be used as dispersion stabilizers. Among them, inorganic dispersants are unlikely to produce harmful ultra fine powders, and due to their steric hindrance. Since the dispersion stability is obtained, the stability is not easily lost even if the reaction temperature is changed, and the toner can be preferably used because it is easily washed and does not adversely affect the toner. Examples of such inorganic dispersants include polyvalent metal phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate and zinc phosphate, carbonates such as calcium carbonate and magnesium carbonate, calcium metasuccinate, calcium sulfate and barium sulfate. Inorganic oxides such as inorganic salts, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, bentonite and alumina can be mentioned.

  These inorganic dispersants may be used alone in an amount of 0.2 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer, and 0.001 to 0.1 parts by mass for the purpose of adjusting the particle size distribution. These surfactants may be used in combination. Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.

  When these inorganic dispersants are used, they may be used as they are, but in order to obtain finer particles, the inorganic dispersant particles can be generated in an aqueous medium. For example, in the case of calcium phosphate, a sodium phosphate aqueous solution and a calcium chloride aqueous solution can be mixed with high-speed stirring to produce water-insoluble calcium phosphate, which enables more uniform and fine dispersion. At the same time, water-soluble sodium chloride salt is produced as a by-product. However, if water-soluble salt is present in the aqueous medium, dissolution of the polymerizable monomer in water is suppressed, and ultrafine toner is generated by emulsion polymerization. This is more convenient. Since it becomes an obstacle when removing the remaining polymerizable monomer at the end of the polymerization reaction, it is better to replace the aqueous medium or desalinate with an ion exchange resin. The inorganic dispersant can be almost completely removed by dissolving with an acid or alkali after completion of the polymerization.

  In the polymerization step, the polymerization is performed at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. When the polymerization is carried out in this temperature range, the release agent or wax to be sealed inside is precipitated by phase separation, and the encapsulation becomes more complete. In order to consume the remaining polymerizable monomer, the reaction temperature can be increased to 90 to 150 ° C. at the end of the polymerization reaction. The polymerized toner particles are filtered, washed, and dried by a known method after the polymerization is completed, and the toner can be obtained by mixing and adhering the inorganic fine powder to the surface. Moreover, it is also one of desirable forms that a classification process is included in the manufacturing process to cut coarse powder and fine powder.

  When the toner of the present invention is produced by a pulverization method, a known method is used. For example, as a toner such as a binder resin, a polymer having a sulfonic acid group, a release agent, a charge control agent, and optionally a colorant. The necessary ingredients and other additives are mixed thoroughly using a mixer such as a Henschel mixer or ball mill, and then melt-kneaded using a heat kneader such as a heating roll, kneader or extruder to make the resins compatible with each other. Disperse or dissolve other toner materials such as magnetic powder in the caulking, cool and solidify, pulverize, classify, surface treatment as necessary to obtain toner particles, add fine powder etc. if necessary By mixing, the toner of the present invention can be obtained. Either the classification or the surface treatment may be performed first. In the classification step, it is preferable to use a multi-division classifier in terms of production efficiency. The pulverization step can be performed by a method using a known pulverizer such as a mechanical impact type or a jet type. In order to obtain a toner having a specific degree of circularity according to the present invention, it is preferable to further heat and pulverize or to add a mechanical impact as an auxiliary. Further, a hot water bath method in which finely pulverized (classified as necessary) toner particles are dispersed in hot water, a method of passing in a hot air stream, or the like may be used.

  As a means for applying a mechanical impact force, for example, a method using a mechanical impact type pulverizer such as a kryptron system manufactured by Kawasaki Heavy Industries, Ltd. or a turbo mill manufactured by Turbo Industry, a mechano-fusion system manufactured by Hosokawa Micron Co., Ltd. There is a method of applying a mechanical impact force to the toner by a force such as a compressive force or a frictional force by pressing the toner to the inside of the casing by a centrifugal force with a blade rotating at high speed, as in a device such as a hybridization system manufactured by the manufacturer.

  In the case of using the mechanical impact method, a thermomechanical impact in which the processing temperature is a temperature in the vicinity of the glass transition point Tg (Tg ± 10 ° C.) of the toner is preferable from the viewpoint of preventing aggregation and productivity. More preferably, it is particularly effective to improve the transfer efficiency to carry out at a temperature in the range of the glass transition point Tg ± 5 ° C. of the toner.

  Furthermore, the toner of the present invention is a method for obtaining a spherical toner by atomizing a molten mixture into air using a disk or a multi-fluid nozzle described in JP-B-56-13945, etc. An emulsion polymerization method typified by a dispersion polymerization method for directly producing a toner using an aqueous organic solvent in which the resulting polymer is insoluble or a soap-free polymerization method for producing a toner by directly polymerizing in the presence of a water-soluble polar polymerization initiator, etc. The toner can also be manufactured by a method of manufacturing the toner used.

  As the binder resin when the toner of the present invention is produced by a pulverization method, styrene such as polystyrene and polyvinyltoluene, and a homopolymer of a substituted product thereof; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene -Vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate Copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer Styrene-vinyl ethyl ether Polystyrene, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer, etc .; poly Methyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or fat Cyclic hydrocarbon resins, aromatic petroleum resins, paraffin wax, carnauba wax and the like can be used alone or in combination. In particular, a styrene copolymer and a polyester resin are preferable in terms of development characteristics, fixing properties, and the like.

  In the toner of the present invention, it is also a very preferable usage form that an inorganic fine powder having an average primary particle diameter of 4 to 80 nm is added as a fluidizing agent in an amount of 0.1 to 4% by mass relative to the whole toner. Inorganic fine powder is added to improve the fluidity of the toner and to make the toner base particles evenly charged. However, the inorganic chargeable powder is treated to make it hydrophobic and adjust the toner charge amount and improve the environmental stability. It is also preferable to provide such functions.

  When the average primary particle size of the inorganic fine powder is larger than 80 nm, good toner fluidity cannot be obtained, and the toner particles are likely to be non-uniformly charged, and the triboelectric chargeability under low humidity is not uniform. Therefore, problems such as an increase in fog, a decrease in image density, and a decrease in durability cannot be avoided. When the average primary particle size of the inorganic fine powder is smaller than 4 nm, the cohesiveness between the inorganic fine particles is increased, and the aggregate is not a primary particle but an aggregate having a wide particle size distribution having a strong cohesive property that is difficult to break even by crushing treatment. It is easy to behave, and image defects due to development of the aggregate, damage to the image carrier or toner carrier, and the like are likely to occur. In order to make the charge distribution of the toner particles more uniform, the average primary particle size of the inorganic fine powder is preferably 6 to 35 nm.

  The average primary particle diameter of the inorganic fine powder is a photograph of the toner magnified by a scanning electron microscope, and is further mapped with the elements contained in the inorganic fine powder by an elemental analysis means such as XMA attached to the scanning electron microscope. The method can be measured by measuring 100 or more primary particles of inorganic fine powder present on the toner surface while adhering to or separating from the toner image, and determining the number average diameter.

  The content of the inorganic fine powder can be quantified using a calibration curve prepared from a standard sample using fluorescent X-ray analysis.

  As the inorganic fine powder added to the toner of the present invention, silica, alumina, titania and the like can be used.

For example, as the silica, both a so-called dry method produced by vapor phase oxidation of silicon halide or dry silica called fumed silica, and so-called wet silica produced from water glass or the like can be used. Further, dry silica with less silanol groups on the surface and inside of the silica fine powder and less production residue such as Na ₂ O, SO ₃ ^2- is preferred. In dry silica, it is also possible to obtain composite fine powders of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with silicon halogen compounds in the production process. Is also included.

  The addition amount of such inorganic fine powder having an average primary particle size of 4 to 80 nm is preferably 0.1 to 4.0 parts by mass with respect to 100 parts by mass of the toner base particles, and the addition amount is 0.1. If the amount is less than part by mass, the effect is not sufficient, and if it exceeds 4.0 parts by mass, the fixability is deteriorated.

  The inorganic fine powder is preferably hydrophobized from the viewpoint of improving characteristics in a high humidity environment. When the inorganic fine powder added to the toner absorbs moisture, the charge amount as the toner is remarkably lowered, and the developability and transferability are easily lowered.

  As treatment agents for hydrophobic treatment, treatment agents such as silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organic silicon compounds, and organic titanium compounds may be used alone or in combination. And may be processed.

  Among them, those treated with silicone oil are preferable, and more preferably, the inorganic fine powder treated with silicone oil at the same time as or after hydrophobizing treatment maintains a high charge amount of toner particles even in a high humidity environment. In addition, the selective developability may be reduced.

  The processing conditions for the inorganic fine powder include, for example, a silylation reaction as the first stage reaction to eliminate active hydrogen groups on the surface by chemical bonding, and then a hydrophobic thin film is formed on the surface with silicone oil as the second stage reaction. can do. As a usage-amount of a silylating agent, 5-50 mass parts is preferable with respect to 100 mass parts of inorganic fine powder. If it is less than 5 parts by mass, it is not sufficient to eliminate the active hydrogen groups on the surface of the inorganic fine particles, and if it exceeds 50 parts by mass, the siloxane compound produced by the reaction between the excess silylating agents acts as a paste, and the inorganic fine particles Aggregation occurs and image defects are likely to occur.

The silicone oil preferably has a viscosity at 25 ° C. of 10 to 200,000 mm ² / s, and more preferably 3,000 to 80,000 mm ² / s. If it is less than 10 mm ² / s, the inorganic fine powder is not stable, and the image quality tends to deteriorate due to heat and mechanical stress. If it exceeds 200,000 mm ² / s, uniform processing tends to be difficult.

  As a method for treating silicone oil, for example, inorganic fine powder treated with a silane compound and silicone oil may be directly mixed using a mixer such as a Henschel mixer, or a method of spraying silicone oil on inorganic fine powder. May be used. Alternatively, after dissolving or dispersing silicone oil in an appropriate solvent, inorganic fine powder may be added and mixed to remove the solvent. A method using a sprayer is more preferable in that the formation of aggregates of inorganic fine powder is relatively small.

  The treatment amount of silicone oil is 1 to 23 parts by mass, preferably 5 to 20 parts by mass with respect to 100 parts by mass of the inorganic fine powder. If the amount of the silicone oil is too small, good hydrophobicity cannot be obtained, and if it is too large, aggregation of inorganic fine particles tends to occur.

The toner of the present invention has a primary particle size of more than 30 nm (preferably a specific surface area of less than 50 m ² / g), more preferably a primary particle size of 50 nm or more (preferably a specific surface area of 30 m ² ) for the purpose of improving cleaning properties. It is also one of preferable modes to add inorganic or organic fine particles close to spherical shape (less than / g). For example, spherical silica particles, spherical polymethylsilsesquioxane particles, spherical resin particles and the like are preferably used.

  The developer used in the present invention may further contain other additives, for example, a lubricant powder such as a polyethylene fluoride powder, a zinc stearate powder, a polyvinylidene fluoride powder, or a cerium oxide powder within a range that does not substantially adversely affect the developer. Abrasives such as silicon carbide powder and strontium titanate powder; or fluidity-imparting agents such as titanium oxide powder and aluminum oxide powder; anti-caking agents; A small amount can also be used. These additives can also be used after hydrophobizing the surface.

  Next, an image forming method and an apparatus unit used in the present invention will be described with reference to the drawings.

  In the image forming method of the present invention, the condition of the developing process is that the toner is carried in a non-contact manner even in the so-called contact one-component development method in which the toner carrying member and the surface of the photosensitive member that is the electrostatic latent image carrying member are in contact. The non-contact one-component development method in which the toner is allowed to fly from the photosensitive member to the photosensitive member can be applied to both, and is not particularly limited.

When the present invention is carried out by the contact one-component developing method, an elastic roller is used as the toner carrier, and a method of coating the toner on the surface of the elastic roller and bringing it into contact with the surface of the photoreceptor can be used. In this case, development is performed by an electric field acting between the photosensitive member and the elastic roller facing the surface of the photosensitive member via the toner. Therefore, the surface of the elastic roller or the vicinity of the surface has an electric potential, and it is necessary to have an electric field in a narrow gap between the surface of the photoreceptor and the toner carrying surface. Therefore, it is possible to use a method in which the elastic rubber of the elastic roller is resistance-controlled in the middle resistance region to keep the electric field while preventing conduction with the surface of the photoreceptor, or a method of providing a thin insulating layer on the surface layer of the conductive roller. . Furthermore, a conductive resin sleeve in which the side facing the surface of the photoreceptor is covered with an insulating material on the conductive roller, or a conductive layer is provided on the side not facing the photoreceptor with the insulating sleeve is also possible. Further, a configuration in which a rigid roller is used as the toner carrying member and the photosensitive member is a flexible material such as a belt is also possible. The resistance of the developing roller as the toner carrier is preferably in the range of 10 ² to 10 ⁹ Ω · cm.

  As the surface shape of the toner carrier, when the surface roughness Ra (μm) is set to 0.2 to 3.0, both high image quality and high durability can be achieved. The surface roughness Ra correlates with the toner conveying ability and the toner charging ability. If the surface roughness Ra of the toner carrier exceeds 3.0, it is difficult not only to make the toner layer on the toner carrier thin, but also the chargeability of the toner is not improved, so that improvement in image quality cannot be expected. . Since the toner carrying ability on the surface of the toner carrier is suppressed by setting it to 3.0 or less, the toner layer on the toner carrier is thinned, and the number of contact between the toner carrier and the toner increases. Since the chargeability of the toner is also improved, the image quality is synergistically improved. On the other hand, when the surface roughness Ra is smaller than 0.2, it becomes difficult to control the toner coat amount.

  In the present invention, the surface roughness Ra of the toner carrier is measured based on JIS surface roughness “JISB 0601” using a surface roughness measuring instrument (Surfcoder SE-30H, manufactured by Kosaka Laboratory Co., Ltd.). This corresponds to the centerline average roughness. Specifically, a 2.5 mm portion as the measurement length a is extracted from the roughness curve in the direction of the center line, the center line of this extraction portion is the X axis, the direction of the vertical magnification is the Y axis, and the roughness curve is When expressed by y = f (x), it means a value obtained by the following formula expressed in micrometers (μm).

  In the image forming method of the present invention, the toner carrier may be rotated in the same direction as the circumferential speed of the photosensitive member, or may be rotated in the opposite direction. When the rotation is in the same direction, it is preferable to set the peripheral speed of the toner carrier to be 1.05 to 3.0 times the peripheral speed of the photosensitive member.

  When the peripheral speed of the toner carrier is less than 1.05 times the peripheral speed of the photoreceptor, the stirring effect received by the toner on the photoreceptor is insufficient, and good image quality cannot be expected. On the other hand, when the peripheral speed ratio exceeds 3.0, toner deterioration due to mechanical stress and toner adhesion to the toner carrier are generated and promoted, which is not preferable.

As the photoreceptor, a photosensitive drum or a photosensitive belt having a photoconductive insulating material layer such as a-Se, Cds, ZnO ₂ , OPC, or a-Si is preferably used. The binder resin of the organic photosensitive layer in the OPC photoreceptor is not particularly limited.

  Of these, polycarbonate resins, polyester resins, and acrylic resins are particularly preferable because they are excellent in transferability and hardly cause toner fusion to the photoreceptor and filming of external additives.

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

  In FIG. 1, 100 is a developing device, 109 is a photosensitive member, 105 is a transfer target such as paper, 106 is a transfer member, 107 is a fixing pressure roller, 108 is a fixing heating roller, and 110 is in contact with the photosensitive member 109. A primary charging member that performs direct charging is shown.

  A bias power source 115 is connected to the primary charging member 110 so as to uniformly charge the surface of the photoconductor 109.

  The developing device 100 contains toner 104 and includes a toner carrier 102 that contacts the photoconductor 109 and rotates in the direction of the arrow. Further, a developing blade 101 for regulating the amount of toner and applying a charge, and a coating roller that rotates in the direction of the arrow in order to attach the toner 104 to the toner carrier 102 and to apply a charge to the toner by friction with the toner carrier 102 103 is also provided. A developing bias power source 117 is connected to the toner carrier 102. A bias power source (not shown) is also connected to the application roller 103, and when negatively charged toner is used, the voltage is more negative than the developing bias, and when positively charged toner is used, the voltage is more positive than the developing bias. Is set.

  A transfer bias power supply 116 having a polarity opposite to that of the photoconductor 109 is connected to the transfer member 106.

  Here, the length in the rotational direction at the contact portion between the photosensitive member 109 and the toner carrier 102, that is, the so-called development nip width is preferably 0.2 mm or more and 8.0 mm or less. If the thickness is less than 0.2 mm, the development amount is insufficient and a satisfactory image density cannot be obtained, and the transfer residual toner is not sufficiently collected. If it exceeds 8.0 mm, the amount of toner supplied becomes excessive, fog suppression is likely to deteriorate, and the wear of the photoreceptor is also adversely affected.

  As the toner carrier, a so-called elastic roller having an elastic layer on the surface is preferably used.

  The hardness of the material of the elastic layer used is preferably 30 to 60 degrees (asker-C / load 1 kg).

The resistance of the toner carrier is preferably in the range of about 10 ² to 10 ⁹ Ωcm in terms of volume resistance. If it is lower than 10 ² Ωcm, for example, if there is a pinhole on the surface of the photoconductor 109, an overcurrent may flow. On the other hand, if it is higher than 10 ⁹ Ωcm, the toner is likely to be charged up by frictional charging, and the image density is likely to be lowered.

The toner coat amount on the toner carrier is preferably 0.1 to 1.5 mg / cm ² . If it is less than 0.1 mg / cm ^2, it is difficult to obtain a sufficient image density, and if it exceeds 1.5 mg / cm ^2, it becomes difficult to uniformly triboelectrically charge all individual toner particles, which causes deterioration of fog suppression. It becomes. Furthermore, 0.2 to 0.9 mg / cm ² is more preferable.

  The toner coating amount is controlled by the developing blade 101, and the developing blade 101 is in contact with the toner carrier 102 through the toner layer. The contact pressure at this time is preferably in the range of 4.9 to 49 N / m (5 to 50 gf / cm). If it is less than 4.9 N / m, it is difficult to control the toner coating amount and uniform triboelectric charging, leading to deterioration of fog suppression. On the other hand, if it exceeds 49 N / m, the toner particles are subjected to an excessive load, so that the deformation of the particles and the fusion of the toner to the developing blade or the toner carrier are likely to occur.

  The free end portion of the restricting member may have any shape as long as a preferable NE length is provided. For example, in addition to a linear cross-sectional shape, an L-shape bent near the tip, or near the tip A shape having a spherical shape is preferably used.

  As the toner coat amount regulating member, a rigid metal blade or the like may be used in addition to the elastic blade for press-fitting toner.

  For the elastic regulating member, it is preferable to select a frictional charging material suitable for charging the toner to a desired polarity. A rubber elastic body such as silicone rubber, urethane rubber or NBR, or a synthetic resin such as polyethylene terephthalate. A metal elastic body such as an elastic body, stainless steel, steel, or phosphor bronze can be used. Moreover, those composites may be sufficient.

  Further, when durability is required for the elastic regulating member and the toner carrying member, it is preferable that the metal elastic member is bonded or coated with a resin or rubber so as to contact the sleeve contact portion.

  Furthermore, an organic substance or an inorganic substance may be added to the elastic regulating member, and it may be melt-mixed or dispersed. For example, the chargeability of the toner can be controlled by adding a metal oxide, metal powder, ceramics, carbon allotrope, whisker, inorganic fiber, dye, pigment, surfactant or the like. In particular, when the elastic body is a molded body such as rubber or resin, fine metal oxide powders such as silica, alumina, titania, tin oxide, zirconia, and zinc oxide, carbon black, and a charge control agent generally used for toners Etc. are also preferably contained.

  Furthermore, application of a DC electric field and / or an AC electric field to the regulating member also improves the uniform thin-layer coating property and uniform charging property due to the loosening action on the toner, achieving a sufficient image density and high quality. Images can be obtained.

  In FIG. 1, a primary charging member 110 uniformly charges a photoconductor 109 that rotates in the direction of an arrow.

  The primary charging member used here is a charging roller having a basic configuration of a central core metal 110b and a conductive elastic layer 110a formed on the outer periphery thereof. The charging roller 110 is brought into contact with the entire surface of the electrostatic latent image carrier with a pressing force, and is rotated following the rotation of the electrostatic latent image carrier 109.

  As a preferable process condition when using a charging roller, the contact pressure of the roller is 4.9 to 490 N / m (5 to 500 gf / cm), and an applied voltage is a DC voltage or an AC voltage superimposed on a DC voltage. In the present invention, an applied voltage of only a DC voltage is preferably used, and a voltage value in this case is used in a range of ± 0.2 to ± 5 kV.

  Other charging means include a method using a charging blade and a method using a conductive brush. These contact charging means have an effect that a high voltage is unnecessary and generation of ozone is reduced as compared with non-contact corona charging. The material of the charging roller and charging blade as the contact charging means is preferably conductive rubber, and a release coating may be provided on the surface thereof. As the releasable coating, nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride), and the like are applicable.

  Following the primary charging step, an electrostatic latent image corresponding to the information signal is formed on the photoconductor 109 by exposure 123 from the light emitting element, and the electrostatic latent image can be developed with toner at a position where it abuts the toner carrier 102. Visualize. Furthermore, in the image forming method of the present invention, particularly in combination with a developing system in which a digital latent image is formed on a photoreceptor, it becomes possible to develop the dot latent image faithfully without disturbing the latent image. . The visible image is transferred to the transfer target 105 by the transfer member 106 and passes between the heating roller 108 and the pressure roller 107 to be fixed to obtain a permanent image. In addition to the heat roller system, the heating and pressure fixing means includes a heating roller having a built-in heating element such as a halogen heater and an elastic pressure roller pressed against the heating roller with a pressing force. A system in which heat is fixed by a heater through a film is also used.

  On the other hand, the untransferred toner remaining on the photoconductor 109 without being transferred is collected by a cleaner 138 having a cleaning blade in contact with the surface of the photoconductor 109, and the photoconductor 109 is cleaned.

  Next, the surface potential of the toner coat layer on the toner carrier will be described as an effective method for directly measuring the charge rising performance and the toner characteristics that determine the occurrence of fogging, which are the characteristics of the present invention.

  The toner and the image forming method of the present invention aim at the fog improvement effect at a low process speed for outputting a high gloss image called a gloss mode, and the manifestation of the above effect can be clearly shown. , 90 mm / sec. In the same environment, that is, a high temperature and high humidity environment of 30 ° C. and 80%. Measure the charge rise characteristics by monitoring the low process speed. Actually, 90 mm / sec. When an image is output at a process speed of 135 mm / sec., The toner carrier is 150% faster. Therefore, the surface potential of the present invention is 135 mm / sec. At the peripheral speed of the toner carrier. Defined as the value in.

  In the toner of the present invention, the surface potential (i) at the start of the rotation of the toner carrier in the non-magnetic one-component developing system in the non-magnetic one-component developing system at the start of rotation for 10 seconds is (i) = − 5 to −45 V, and 60 The surface potential (ii) at the second is (ii) = − 5 to −50 V, and the relationship (i / ii) between (i) and (ii) is (i / ii) = 0.5 to 1.3. More preferably, the surface potential (i) is (i) = − 7 to −40V, the surface potential (ii) is (ii) = − 7 to −45V, and the (i / ii) Is (i / ii) = 0.7-1.

  If the surface potential (i) at 10 seconds after the start of rotation is less than −5 V, the toner layer that can be developed is not sufficiently formed on the toner carrier, and a stable density cannot be output. Unsuitable.

  On the other hand, if it exceeds −45 V, the charged potential is excessive, and the coat surface is disturbed by electrostatic repulsion between the overcharged toners on the toner carrier, so that the uniformity of the halftone image is deteriorated.

  If the surface potential (ii) at 60 seconds from the start of rotation is less than −5 V, the toner charging potential is insufficient, the background fogging amount is large, and it is not practical.

  On the other hand, when the voltage exceeds −50 V, the charged potential is excessive, and the coating surface is disturbed, so that a uniform halftone image cannot be reproduced.

  If the ratio (i / ii) of the surface potential (i) at 10 seconds to the surface potential (ii) at 60 seconds is less than 0.5, the coating amount on the toner carrier is not stable and the image Gradation reproducibility with stable density cannot be obtained.

  When (i / ii) exceeds 1.3, the surface potential at the start of rotation jumps all at once, and then the potential is attenuated. Therefore, the coating amount on the toner carrier is unstable, and an appropriate image density is obtained. Gradation reproducibility cannot be obtained.

  The surface potential is measured by setting a developing device of a cartridge EP-85 (manufactured by Canon Inc.) of a commercially available laser beam printer LBP-2510 (manufactured by Canon Inc.) on an idle rotating jig, and setting the toner carrier to a peripheral speed of 135 mm / sec. . The value at 10 seconds and the value at 60 seconds when rotating at 650 were used. Specifically, 200 g of sample toner is refilled and left overnight in a high-temperature and high-humidity environment (temperature 30 ° C., humidity 80% RH), the probe is opposed to the toner carrier with a 1 mm gap, and a surface potential meter model 344 ( The rise of the charging potential was measured using a Trek company).

  An example of the rise of the potential read by the memory high coder (manufactured by Hioki Electric Co., Ltd.) is shown in FIG. (Profile when idle rotating for 90 seconds at toner carrier peripheral speed of 135 mm / sec.).

  Next, an image forming method and an apparatus unit using the toner of the present invention will be described with reference to the drawings.

  3 and 4 are schematic views of an image forming apparatus that collectively transfers multiple toner images onto a recording material using an intermediate transfer member in the image forming method of the present invention.

  FIG. 3 is a schematic view of an image forming apparatus that batch-transfers multiple toner images onto a recording material using an intermediate transfer drum in the image forming method of the present invention.

  The surface of the photosensitive drum 1 as a latent image carrier is brought into contact with a rotatable charging roller 2 to which a charging bias voltage as a charging member is applied while rotating to uniformly primary-charge the surface of the photosensitive drum, A first electrostatic latent image is formed on the photosensitive drum 1 by a laser beam E emitted from a light source device L as an exposure unit. The formed first electrostatic latent image is developed with the black toner in the black developing device 4Bk as a first developing device provided in the rotatable rotary unit 10 to form a black toner image. The black toner image formed on the photosensitive drum 1 is electrostatically primary transferred onto the intermediate transfer drum 5 by the action of the transfer bias voltage applied to the conductive support of the intermediate transfer drum. Next, a second electrostatic latent image is formed on the surface of the photosensitive drum 1 in the same manner as described above, and the rotary unit 10 is rotated so that the yellow toner in the yellow developing device 4Y as the second developing device is used. Development is performed to form a yellow toner image, and the yellow toner image is electrostatically primary transferred onto the intermediate transfer drum 5 on which the black toner image is primarily transferred. Similarly, the third electrostatic latent image and the fourth electrostatic latent image are rotated as the magenta toner and the fourth developing unit in the magenta developing unit 4M as the third developing unit by rotating the rotary unit 10. Development and primary transfer are sequentially performed with the cyan toner in the cyan developing device 4C, and the toner images of the respective colors are primarily transferred onto the intermediate transfer drum 5. The multiple toner image primarily transferred onto the intermediate transfer drum 5 is electrostatically applied onto the recording material P by the action of the transfer bias voltage from the second transfer device 8 positioned on the opposite side via the recording material P. Secondary transfer is performed at once. The multiple toner image secondarily transferred onto the recording material P is heat-fixed on the recording material P by a fixing device 9 having a heating roller and a pressure roller. The transfer residual toner remaining on the surface of the photosensitive drum 1 after the transfer is collected by a cleaner having a cleaning blade in contact with the surface of the photosensitive drum 1, and the photosensitive drum 1 is cleaned.

  In the primary transfer from the photosensitive drum 1 to the intermediate transfer drum 5, a transfer current is obtained by applying a bias from a power source (not shown) to the conductive support of the intermediate transfer drum 5 as the first transfer device. The image is transferred.

  The intermediate transfer drum 5 includes a conductive support 5a that is a rigid body and an elastic layer 5b that covers the surface.

  As the conductive support 5a, a metal or an alloy such as aluminum, iron, copper, and stainless steel, and a conductive resin in which carbon or metal particles are dispersed can be used. The thing which penetrated the axis | shaft in the center, the thing which gave reinforcement to the inside of a cylinder, etc. are mentioned.

  The elastic layer 5b is not particularly limited, but styrene-butadiene rubber, high styrene rubber, butadiene rubber, isoprene rubber, ethylene-propylene copolymer, nitrile butadiene rubber (NBR), chloroprene rubber, butyl rubber, silicone. Elastomer rubbers such as rubber, fluorine rubber, nitrile rubber, urethane rubber, acrylic rubber, epichlorohydrin rubber and norbornene rubber are preferably used. A resin such as a polyolefin resin, a silicone resin, a fluorine resin, or a polycarbonate, and a copolymer or a mixture thereof may be used.

  Further, a surface layer in which lubricant powder having high lubricity and water repellency is dispersed in an arbitrary binder may be provided on the surface of the elastic layer.

  The lubricant is not particularly limited, but various fluororubbers, fluoroelastomers, fluorocarbons and polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymers in which fluorine is bonded to graphite or graphite. (ETFE) and fluorine compounds such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), silicone compounds such as silicone resin particles, silicone rubber and silicone elastomer, polyethylene (PE), polypropylene (PP), polystyrene ( PS), acrylic resin, polyamide resin, phenol resin, epoxy resin and the like are preferably used.

  In addition, a conductive agent may be added to the surface layer binder in order to control resistance. Examples of the conductive agent include various conductive inorganic particles and carbon black, an ionic conductive agent, a conductive resin, and a conductive particle-dispersed resin.

  The multiple toner images on the intermediate transfer drum 5 are secondarily transferred onto the recording material P all at once by the second transfer device 8, and the transfer means 8 is a non-contact electrostatic transfer means or a transfer roller using a corona charger. In addition, contact electrostatic transfer means using a transfer belt can be used.

  The fixing device 9 is replaced with a heat roller fixing device having a heating roller 9a and a pressure roller 9b, and the toner image on the recording material P is heated by heating a film in contact with the toner image on the recording material P. Also, a film heat fixing device that heat-fixes a multiple toner image on the recording material P can be used.

  Instead of the intermediate transfer drum as the intermediate transfer member used in the image forming apparatus shown in FIG. 3, it is also possible to batch transfer the multiple toner images onto the recording material using an intermediate transfer belt. The configuration of the intermediate transfer belt is shown in FIG.

  The toner image formed and carried on the photosensitive drum 1 is formed by the primary transfer bias applied from the primary transfer roller 42 to the intermediate transfer belt 40 in the process of passing through the nip portion between the photosensitive drum 1 and the intermediate transfer belt 40. Due to the applied electric field, primary transfer is sequentially performed on the outer peripheral surface of the intermediate transfer belt 40.

  A primary transfer bias for sequentially superimposing and transferring the first to fourth color toner images from the photosensitive drum 1 to the intermediate transfer belt 40 is applied from a bias power supply 44 with a polarity opposite to that of the toner.

  In the primary transfer process of the first to third color toner images from the photosensitive drum 1 to the intermediate transfer belt 40, the secondary transfer roller 43 b and the intermediate transfer belt cleaner 49 can be separated from the intermediate transfer belt 40.

  Reference numeral 43b denotes a secondary transfer roller, which is supported in parallel with the secondary transfer counter roller 43a so as to be separated from the lower surface portion of the intermediate transfer belt 40.

  When the composite color toner image transferred onto the intermediate transfer belt 40 is transferred to the transfer material P, the secondary transfer roller 43b is brought into contact with the intermediate transfer belt 40, and the intermediate transfer belt 40 and the secondary transfer roller 43b. The transfer material P is fed to the contact nip at a predetermined timing, and a secondary transfer bias is applied from the bias power source 46 to the secondary transfer roller 43b. The composite color toner image is secondarily transferred from the intermediate transfer belt 40 to the transfer material P by the secondary transfer bias.

  After the image transfer to the transfer material P is completed, a cleaning charging member 49 is brought into contact with the intermediate transfer belt 40, and a bias having a polarity opposite to that of the photosensitive drum 1 is applied from the bias power supply 45 to transfer the image to the transfer material P. Instead, a charge having a polarity opposite to that of the photosensitive drum 1 is applied to the toner (transfer residual toner) remaining on the intermediate transfer belt 40.

  The transfer residual toner is electrostatically transferred to the photosensitive drum 1 at and near the nip portion with the photosensitive drum 1 to clean the intermediate transfer member.

  The intermediate transfer belt includes a belt-shaped base layer and a surface treatment layer provided on the base layer. The surface treatment layer may be composed of a plurality of layers.

  Rubber, elastomer, or resin can be used for the base layer and the surface treatment layer. For example, as rubber and elastomer, natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, butyl rubber, ethylene-propylene rubber, ethylene-propylene terpolymer, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, acrylonitrile butadiene rubber, Urethane rubber, syndiotactic 1,2-polybutadiene, epichlorohydrin rubber, acrylic rubber, silicone rubber, fluorine rubber, polysulfurized rubber, polynorbornene rubber, hydrogenated nitrile rubber and thermoplastic elastomer (for example, polystyrene, polyolefin, 1 type or 2 types or more selected from the group consisting of polyvinyl chloride, polyurethane, polyamide, polyester, fluororesin, etc. can be used.However, it is not limited to the said material. As the resin, a resin such as a polyolefin resin, a silicone resin, a fluorine resin, or a polycarbonate can be used. A copolymer or a mixture of these resins may be used.

  As the base layer, the rubber, elastomer and resin described above can be used in the form of a film. In addition, a material obtained by coating, dipping, or spraying the above-described rubber, elastomer, or resin on one side or both sides of a core layer in the form of a woven fabric, a nonwoven fabric, a thread, or a film may be used.

  The material constituting the core layer is, for example, natural fibers such as cotton, silk, hemp and wool; regenerated fibers such as chitin fiber, alginic acid fiber and regenerated cellulose fiber; semisynthetic fibers such as acetate fiber; polyester fiber, nylon fiber, Synthetic fibers such as acrylic fiber, polyolefin fiber, polyvinyl alcohol fiber, polyvinyl chloride fiber, polyvinylidene chloride fiber, polyurethane fiber, polyalkyl paraoxybenzoate fiber, polyacetal fiber, aramid fiber, polyfluoroethylene fiber and phenol fiber; carbon fiber, One or more selected from the group consisting of inorganic fibers such as glass fibers and boron fibers; metal fibers such as iron fibers and copper fibers can be used. Of course, the material is not limited to the above.

  Further, a conductive agent may be added to the base layer and the surface treatment layer in order to adjust the resistance value of the intermediate transfer member. Although it does not specifically limit as a electrically conductive agent, For example, metal powder, such as carbon, aluminum, and nickel, metal oxides, such as a titanium oxide, and quaternary ammonium salt containing polymethyl methacrylate, polyvinyl aniline, polyvinyl pyrrole, One kind or two or more kinds selected from the group consisting of polydiacetylene, polyethyleneimine, boron-containing polymer compounds, conductive polymer compounds such as polypyrrole, and the like can be used. However, it is not limited to the said electrically conductive agent.

  Further, a lubricant may be added as necessary to improve the slipperiness of the surface of the intermediate transfer member and improve the transferability.

  The lubricant is not particularly limited, but various fluororubbers, fluoroelastomers, fluorocarbons and polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymers in which fluorine is bonded to graphite or graphite. (ETFE) and fluorine compounds such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), silicone compounds such as silicone resin, silicone rubber, and silicone elastomer, polyethylene (PE), polypropylene (PP), polystyrene (PS ), Acrylic resin, polyamide resin, phenol resin, epoxy resin and the like are preferably used.

  Next, an image forming method will be described with reference to FIG. 5 in which toner images of respective colors are formed in a plurality of image forming units and transferred onto the same transfer material in sequence.

  Here, first, second, third and fourth image forming units 29a, 29b, 29c and 29d are arranged in parallel, and each image forming unit is a dedicated electrostatic latent image holding member, a so-called photosensitive drum. 19a, 19b, 19c and 19d.

  The photosensitive drums 19a to 19d have latent image forming means 23a, 23b, 23c and 23d, developing units 17a, 17b, 17c and 17d, transfer discharge units 24a, 24b, 24c and 24d, and cleaning units 18a and 18b on the outer peripheral side thereof. , 18c and 18d are arranged.

  With such a configuration, first, a latent image of, for example, a yellow component color in the original image is formed on the photosensitive drum 19a of the first image forming unit 29a by the latent image forming unit 23a. The latent image is converted into a visible image by the developer having yellow toner of the developing unit 17a, and transferred to the recording material S as a transfer material by the transfer unit 24a.

  As described above, while the yellow image is transferred to the transfer material S, the second image forming unit 29b forms a magenta component color latent image on the photosensitive drum 19b, and subsequently has the magenta toner of the developing unit 17b. A visible image is formed with the developer. This visible image (magenta toner image) is transferred to a predetermined position of the transfer material S when the transfer material S, which has been transferred by the first image forming unit 29a, is transferred to the transfer unit 24b. The

  Thereafter, cyan and black images are formed by the third and fourth image forming portions 29c and 29d in the same manner as described above, and the cyan and black colors are transferred onto the same transfer material S. To do. When such an image forming process is completed, the transfer material S is conveyed to the fixing unit 22 and the image on the transfer material S is fixed. As a result, a multicolor image is obtained on the transfer material S. The photosensitive drums 19a, 19b, 19c, and 19d after the transfer are removed from the residual toner by the cleaning units 18a, 18b, 18c, and 18d, and are used for subsequent latent image formation.

  In the image forming apparatus, a conveyance belt 25 is used to convey the recording material S as a transfer material. In FIG. 5, the transfer material S is conveyed from the right side to the left side. Each image forming section 29a, 29b, 29c and 29d passes through each transfer section 24a, 24b, 24c and 24d and undergoes transfer.

  In this image forming method, a transport belt using a mesh of Tetoron (registered trademark) fiber as a transport means for transporting a transfer material and a polyethylene terephthalate resin, a polyimide resin, and a urethane resin from the viewpoint of durability. A conveyor belt using such a thin dielectric sheet is used.

  When the transfer material S passes through the fourth image forming portion 29d, an AC voltage is applied to the static eliminator 20, the transfer material S is neutralized and separated from the belt 25, and then enters the fixing device 22 where the image is fixed and discharged. It is discharged from the outlet 26.

  In this image forming method, each of the image forming portions is provided with an independent electrostatic latent image holding member, and the transfer material is a belt-type conveying unit, and the transfer portion of each electrostatic latent image holding member is sequentially transferred. You may comprise so that it may be sent to.

  In this image forming method, an electrostatic latent image holding member common to the image forming unit is provided, and the transfer material is repeatedly sent to the transfer unit of the electrostatic latent image holding member by a drum-type conveying unit. In other words, each color may be transferred.

  However, since the conveyance belt has a high volume resistance, the conveyance belt increases the charge amount in the process of repeating the transfer several times as in the color image forming apparatus. For this reason, uniform transfer cannot be maintained unless the transfer current is sequentially increased for each transfer.

  Since the toner of the present invention has excellent transferability, even if the charge of the conveying means increases every time the transfer is repeated, the transferability of the toner in each transfer can be made uniform with the same transfer current, and a high-quality high-quality image can be obtained. It will be.

  FIG. 6 shows an image formation using a transfer belt as a secondary transfer means when a color toner image of four colors transferred onto the intermediate transfer drum using the intermediate transfer drum is secondarily transferred collectively to a recording material. It is explanatory drawing of an apparatus.

In the apparatus system shown in FIG. 6, the developers 244-1, 244-2, 244-3, and 244-4 are respectively provided with a developer having cyan toner, a developer having magenta toner, a developer having yellow toner, and a black toner. A developer having toner is introduced to develop the electrostatic image formed on the photoreceptor 241, and each color toner image is formed on the photoreceptor 241. The photosensitive member 241 is a photosensitive drum or a photosensitive belt having a photoconductive insulating material layer such as a-Se, Cds, ZnO ₂ , OPC, or a-Si. The photoreceptor 241 is rotated in the direction of the arrow by a driving device (not shown).

  As the photoreceptor 241, an amorphous silicon photosensitive layer or a photoreceptor having an organic photosensitive layer is preferably used.

  The organic photosensitive layer may be a single layer type in which the photosensitive layer contains a charge generation material and a substance having charge transport performance in the same layer, or a function-separated type photosensitive layer having the charge generation layer as a component. It may be. A laminated photosensitive layer having a structure in which a charge generation layer and then a charge transport layer are laminated in this order on a conductive substrate is one preferred example.

  The binder resin for the organic photosensitive layer is particularly a polycarbonate resin, a polyester resin, or an acrylic resin, and has good transferability and cleaning properties, and poor cleaning, toner fusion to the photoreceptor, and filming of external additives are unlikely to occur.

  In the charging process, there are a non-contact method using a corona charger 241 and a contact type method using a roller or the like. For efficient uniform charging, simplification, and low ozone generation, a contact type as shown in FIG. 6 is preferably used.

  The charging roller 242 has a basic configuration of a central cored bar 242b and a conductive elastic layer 242a that forms the outer periphery thereof. The charging roller 242 is pressed against the surface of the photoconductor 241 with a pressing force, and is driven to rotate as the photoconductor 241 rotates.

  As a preferable process condition when using a charging roller, the contact pressure of the roller is 4.9 to 490 N / m (5 to 500 gf / cm), and when a DC voltage is superimposed on an AC voltage, an AC current is used. Voltage = 0.5-5 kVpp, AC frequency = 50 Hz-5 kHz, DC voltage = ± 0.2- ± 1.5 kV, and DC voltage = ± 0.2- ± 5 kV when DC voltage is used.

  Other charging means include a method using a charging blade and a method using a conductive brush. These contact charging means are effective in that a high voltage is unnecessary and generation of ozone is reduced.

  The material of the charging roller and charging blade as the contact charging means is preferably conductive rubber, and a release coating may be provided on the surface thereof. As the releasable coating, nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride), and the like are applicable.

  The toner image on the photoreceptor is transferred to an intermediate transfer drum 245 to which a voltage (for example, ± 0.1 to ± 5 kV) is applied. The surface of the photoreceptor after the transfer is cleaned by a cleaning unit 249 having a cleaning blade 248.

  The intermediate transfer drum 245 includes a pipe-shaped conductive metal core 245b and a medium-resistance elastic layer 245a formed on the outer peripheral surface thereof. The cored bar 245b may be a plastic pipe with conductive plating.

The medium resistance elastic layer 245a is made of elastic material such as silicone rubber, Teflon (registered trademark) rubber, chloroprene rubber, urethane rubber, EPDM (ethylene propylene diene terpolymer), carbon black, zinc oxide, oxidized It is a solid or foamed layer in which conductivity imparting materials such as tin and silicon carbide are blended and dispersed to adjust the electric resistance value (volume resistivity) to a medium resistance of 10 ⁵ to 10 ¹¹ Ω · cm.

  The intermediate transfer drum 245 is disposed in parallel with the photoconductor 241 and is in contact with the lower surface of the photoconductor 241, and rotates in the counterclockwise direction indicated by an arrow at the same peripheral speed as the photoconductor 241.

  The first color toner image formed and supported on the surface of the photosensitive member 241 passes through the transfer nip where the photosensitive member 241 and the intermediate transfer drum 245 are in contact with each other, and is applied to the transfer nip region by the transfer bias applied to the intermediate transfer drum 245. The intermediate transfer is sequentially performed on the outer surface of the intermediate transfer drum 245 by the formed electric field.

  If necessary, the surface of the intermediate transfer drum 245 is cleaned by a removable cleaning unit 280 after the toner image is transferred onto the transfer material. When there is a toner image on the intermediate transfer drum, the cleaning means 280 is separated from the surface of the intermediate transfer member so as not to disturb the toner image.

  A transfer unit is disposed in parallel with the intermediate transfer drum 245 and brought into contact with the lower surface of the intermediate transfer drum 245. The transfer unit 247 is, for example, a transfer roller or a transfer belt, and has the same peripheral speed as the intermediate transfer drum. To rotate clockwise. The transfer unit may be disposed so as to directly contact the intermediate transfer drum, or a belt or the like may be disposed between the intermediate transfer drum and the transfer unit.

  In the case of the transfer roller, the basic configuration is a central core metal and a conductive elastic layer formed on the outer periphery thereof.

  Common materials can be used as the intermediate transfer drum and the transfer roller. By setting the volume resistivity of the elastic layer of the transfer roller smaller than the volume resistivity of the elastic layer of the intermediate transfer drum, the applied voltage to the transfer roller can be reduced and a good toner image is formed on the transfer material In addition, it is possible to prevent the transfer material from being wound around the intermediate transfer member. In particular, the volume specific resistance value of the elastic layer of the intermediate transfer member is particularly preferably 10 times or more than the volume specific resistance value of the elastic layer of the transfer roller.

  The hardness of the intermediate transfer drum and the transfer roller is measured according to JIS K-6301. The intermediate transfer drum used in the present invention is preferably composed of an elastic layer belonging to a range of 10 to 40 degrees, while the hardness of the elastic layer of the transfer roller is harder than the hardness of the elastic layer of the intermediate transfer drum. Those having a value of ˜80 degrees are preferable for preventing the transfer material from being wound around the intermediate transfer drum. When the hardness of the intermediate transfer drum and that of the transfer roller are reversed, a recess is formed on the transfer roller side, and the transfer material is easily wound around the intermediate transfer drum.

  In FIG. 6, a transfer belt 247 is disposed below the intermediate transfer drum 245. The transfer belt 247 is stretched between two rollers arranged in parallel to the axis of the intermediate transfer drum 245, that is, a bias roller 247a and a tension roller 247c, and is driven by a driving unit (not shown). Since the transfer belt 247 is configured such that the bias roller 247a side can move in the arrow direction around the tension roller 247c side, the transfer belt 247 can contact and separate from the intermediate transfer drum 245 in the arrow direction from below. A desired secondary transfer bias is applied to the bias roller 247a by a secondary transfer bias source 247d, while the tension roller 247c is grounded.

Next, regarding the transfer belt 247, in this embodiment, carbon is dispersed in a thermosetting urethane elastomer, and the thickness is controlled to about 300 μm and the volume resistivity is 10 ⁸ to 10 ¹² Ω · cm (when 1 kV is applied). A rubber belt controlled to 20 μm fluororubber and a volume resistivity of 10 ¹⁵ Ω · cm (when 1 kV was applied) was used. The outer diameter is a tube shape with a circumference of 80 × width of 300 mm.

  The transfer belt 247 is applied with a tension that extends about 5% by the bias roller 247a and the tension roller 247c.

  The transfer means 247 is rotated with a difference in speed or peripheral speed from the intermediate transfer drum 245. The transfer material 246 is conveyed between the intermediate transfer drum 245 and the transfer unit 247, and at the same time, a bias having a polarity opposite to the frictional charge of the toner is applied to the transfer unit 247 from the secondary transfer bias source 247d. The toner image on the transfer drum 245 is transferred to the surface side of the transfer material 246.

  As the material of the transfer rotator, the same material as that of the charging roller can be used. As a preferable transfer process condition, the roller contact pressure is 4.9 to 490 N / m (5 to 500 gf / cm). The DC voltage is ± 0.2 to ± 10 kV.

For example, the conductive elastic layer 247a1 of the bias roller 247a has a volume resistance of about 10 ⁶ to 10 ¹⁰ Ωcm such as polyurethane, ethylene-propylene-diene terpolymer (EPDM) in which a conductive material such as carbon is dispersed. Made with body. A bias is applied to the cored bar 247a2 by a constant voltage power source. The bias condition is preferably ± 0.2 to ± 10 kV.

  Next, the transfer material 246 is conveyed to a fixing device 281 having a heating roller incorporating a heating element such as a halogen heater and an elastic pressure roller pressed against it with a pressing force. By passing between the pressure rollers, the toner image is fixed to the transfer material by heating and pressing. A method of fixing with a heater through a film may be used.

  Hereinafter, the present invention will be specifically described with reference to production examples and examples, but this does not limit the present invention in any way. In addition, all the parts in the following mixing | blending are a mass part.

(Production example of sulfur-containing polymer 1)
In a pressurizable reaction vessel equipped with a reflux tube, a stirrer, a thermometer, a nitrogen introduction tube, a dropping device and a decompression device, 250 parts of methanol as a solvent, 150 parts of 2-butanone and 100 parts of 2-propanol, styrene as a monomer 81 parts, 10 parts of 2-ethylhexyl acrylate, and 9 parts of 2-acrylamido-2-methylpropanesulfonic acid were added and heated to reflux temperature with stirring. A solution obtained by diluting 1 part of t-butylperoxy-2-ethylhexanoate as a polymerization initiator with 20 parts of 2-butanone was added dropwise over 30 minutes, and stirring was continued for 5 hours. Further, t-butylperoxy-2 was further added. -A solution obtained by diluting 1 part of ethylhexanoate with 20 parts of 2-butanone was added dropwise over 30 minutes, and the mixture was further stirred for 5 hours to complete the polymerization. Further, 500 parts of deionized water was added while maintaining the temperature, and after stirring for 2 hours at 80 to 100 revolutions per minute so as not to disturb the interface between the organic layer and the aqueous layer, the mixture was allowed to stand for 30 minutes and separated. The aqueous layer was discarded, and anhydrous sodium sulfate was added to the organic layer for dehydration.

  Next, the polymer obtained after the polymerization solvent was distilled off under reduced pressure was coarsely pulverized to 100 μm or less using a cutter mill equipped with a 150 mesh screen. The obtained sulfur-containing polymer had a weight average molecular weight of Mw = 22000 and Tg of about 75 ° C. Let the obtained sulfur-containing polymer be the sulfur-containing polymer 1.

(Production example of sulfur-containing polymers 2 to 5)
In Production Example 1 of the sulfur-containing polymer, the amount of the monomer used was changed to the contents shown in Table 1, and the molecular weight shown in Table 1 was controlled by adjusting the amount of the initiator and the polymerization temperature. In the same manner, sulfur-containing polymers 2 to 5 were produced.

<Example 1>
400 parts of ion-exchanged water was charged with 0.1M-Na ₃ PO ₄ aqueous solution 450 parts, the mixture was heated to 50 ° C., using a TK-type homomixer (manufactured by Tokushu Kika Kogyo) at 10,000rpm Stir. To this, 68 parts of 1.0 M CaCl ₂ aqueous solution was added to obtain an aqueous medium containing calcium phosphate.

on the other hand,
Styrene 81 parts n-butyl acrylate 19 parts C.I. I. Pigment Blue 15: 3 5 parts Sulfur-containing polymer 1 1 part Bontron E-88 (manufactured by Orient Chemical Industry Co., Ltd.) 0.8 part Saturated polyester 10 parts (acid value 10 mgKOH / g, peak molecular weight 11,000, Tg = 75 ° C)
Ester wax (endothermic peak = 70 ° C) 12 parts divinylbenzene 0.2 parts The above formulation is heated to 60 ° C and uniformly dissolved and dispersed at 6000 rpm using a TK homomixer (manufactured by Koki Kogyo Kogyo). did. In this, 3.5 parts of polymerization initiators 2,2′-azobis (2,4-dimethylvaleronitrile) were dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was put into the aqueous medium, and stirred at 12,000 rpm with a TK homomixer in an N ₂ atmosphere at 60 ° C. to granulate the polymerizable monomer composition. .

  Then, while stirring with a paddle stirring blade, NaOH was added to adjust the pH to 10 when 5 hours had elapsed, and then the temperature was raised to 80 ° C. at a rate of temperature increase of 40 ° C./h and reacted for 5 hours. After completion of the polymerization reaction, the residual monomer was distilled off under reduced pressure. After cooling, hydrochloric acid was added, and the mixture was stirred for 6 hours to dissolve the calcium phosphate salt.

  Thereafter, filtration, washing with ion exchange water, and drying were performed to obtain toner particles (1).

To 100 parts of the toner particles, 0.1 part of Bontron E-88 (manufactured by Orient Chemical Co., Ltd.) is added as a charge control agent (b) to be added externally, and the peripheral speed is increased by a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.). Dry mixing was performed for 1 minute at 35 m / s. Furthermore, as a fluidity improver, 1.5 parts of hydrophobic silica fine powder (BET: 180 m ^{2 /} g) treated with hexamethyldisilazane and then with silicone oil was additionally mixed, and the peripheral speed was 35 m with the same Henschel mixer. The toner (1) of the present invention was dry-mixed for 5 minutes under the conditions of / s.

  When the weight average particle diameter and average circularity of toner (1) were calculated using a flow type particle image measuring apparatus manufactured by Toa Medical Electronics Co., Ltd., they were 6.5 μm and 0.979, respectively.

  Table 2 shows the physical property values of the toner.

  The toner (1) is a non-magnetic one-component developer (1), and the developer is used in an image forming apparatus as shown in FIG. 7, under high temperature and high humidity conditions (temperature 30 ° C., humidity 80% RH), normal temperature. Image evaluation was performed under normal humidity conditions (temperature 23 ° C., humidity 50% RH) and low temperature low humidity conditions (temperature 15 ° C., humidity 10% RH). The image forming apparatus will be described below.

  FIG. 7 is a schematic view of a modified 1200 dpi laser beam printer (manufactured by Canon: LBP-840) using a non-magnetic one-component contact development type electrophotographic process. In this example, an apparatus in which the following parts (a) to (h) were modified was used.

  (A) The charging method of the apparatus was direct charging performed by contacting a rubber roller, and the applied voltage was a direct current component (-1200 V).

(B) The toner carrier was changed to a medium resistance rubber roller (diameter 16 mm, hardness ASKER-C 45 degrees, resistance 10 ⁵ Ω · cm) made of silicone rubber dispersed with carbon black, and contacted with the photoreceptor.

  (C) The toner carrying member was driven so that the rotational peripheral speed of the toner carrying member was in the same direction at the contact portion with the photosensitive member, and was 150% of the photosensitive member rotational peripheral speed.

  (D) The photoconductor was changed to the following.

The photoreceptor used here was an Al cylinder as a substrate, and layers having the following constitution were sequentially laminated by dip coating to produce a photoreceptor.
Conductive coating layer: Mainly composed of a powder of tin oxide and titanium oxide dispersed in a phenol resin. Film thickness 15 μm.
-Undercoat layer: Mainly composed of modified nylon and copolymer nylon. Film thickness 0.6 μm.
Charge generation layer: Mainly composed of a titanyl phthalocyanine pigment having absorption in a long wavelength region dispersed in a butyral resin. Film thickness 0.6 μm.
Charge transport layer: Mainly composed of a hole-transporting triphenylamine compound dissolved in a polycarbonate resin (molecular weight 20,000 by Ostwald viscosity method) at a mass ratio of 8:10. Film thickness 20 μm.

  (E) As a means for applying the toner to the toner carrier, an application roller made of foamed urethane rubber was provided in the developing unit and brought into contact with the toner carrier. A voltage of about −550 V is applied to the application roller.

  (F) In order to control the coat layer of the toner on the toner carrier, a 0.1 mm phosphor bronze blade coated with a 30 μm thick polyamide resin was used.

  (G) Only the DC component (-450 V) was applied during development.

  (H) The process speed was modified to 180 mm / sec (peripheral speed of toner carrier 270 mm / sec).

  A commercially available paint is applied very thinly on the surface of a rubber roller having the same diameter, the same hardness, and the same resistance as the toner carrier used in the image forming apparatus, and after temporarily assembling the image forming apparatus, the rubber roller is removed, and an optical microscope By observing the surface of the toner layer control blade, the NE length was measured.

  The NE length was 1.05 mm.

  The electrophotographic apparatus was remodeled and process conditions were set as follows in order to conform to the remodeling of these process cartridges.

  The modified device uses a roller charger (applying only direct current) to uniformly charge the image carrier. Subsequent to charging, an image portion is exposed with a laser beam to form an electrostatic latent image, and a visible image is formed with toner, and then the toner image is transferred to a transfer material by a roller to which a voltage of +700 V is applied.

  As for the photosensitive member charging potential, the dark portion potential was set to -600V, and the bright portion potential was set to -150V.

  Under the above conditions, printing is performed under the high temperature and high humidity environment (30 ° C., 80% RH), the normal temperature and normal humidity environment (23 ° C., 50% RH), and the low temperature low humidity environment (15 ° C., 10% RH). As an index for checking the fog evaluation immediately after outputting 20000 copies of an original image with a ratio of 2% and outputting 20000 copies, and evaluating the uniformity of a halftone image and the evaluation of gradation reproducibility, 3 The fluctuation range with respect to the image density of the standard was measured.

  Further, after being left in each environment for one day, the process speed was switched to a low speed mode of 90 mm / sec (peripheral speed of toner carrier: 135 mm / sec), and the fifth fog was evaluated.

Details of the evaluation method are shown below.
(1) Image fog The fog density (%) is calculated from the difference between the whiteness of the white portion of the printout image and the whiteness of the transfer paper measured by “REFLECTMETER MODEL TC-6DS” (manufactured by Tokyo Denshoku). Image fog at the end of durability evaluation was evaluated. The filter used was amber light for cyan, blue for yellow, and green for magenta and black.
A: Very good Less than 0.5% B: Good 0.5% or more to less than 1.0% C: No problem in practical use 1.0% or more to less than 1.5% D: Somewhat difficult 1.5% more than

  In the present invention, the rank C or higher is within the allowable range.

(2) Halftone uniformity An original chart in which dots of 45 μm are arranged at intervals of 200 μm was output, and the halftone uniformity caused by missing dots, missing dots, and toner scattering was visually evaluated. .
A: Very good Very uniform B: Good A little strange in uniformity, but almost uniform.
C: No problem in practical use Spots are confirmed in some areas, but almost halftone is reproduced.
D: Somewhat difficult The entire surface is cluttered due to dot reproduction spots and scattering.

(3) Tone reproducibility Three levels of original images with an image density of 0.5, 0.8, and 1.4 are output at the beginning of durability (when 50 sheets are passed). An image was output, the maximum density difference through each density level was determined, and tone reproducibility was evaluated based on that value.

The image density was measured using a “Macbeth reflection densitometer RD918” (manufactured by Macbeth Co., Ltd.) to measure the relative density with respect to an image of a white background portion having a document density of 0.00.
A: Very good Less than 0.15 B: Good 0.15 or more, less than 0.25 C: No practical problem 0.25 or more, less than 0.3 D: Somewhat difficult 0.3 or more

  The toner (1) showed good quality with a stable density, an image after a printout test of 20,000 sheets, no fog, uniform halftone image. Moreover, in all environments, even at a low process speed, which is a high-quality gloss mode after being left standing, it was good with no noticeable fog.

<Example 2>
Evaluation was made in the same manner as in Example 1 except that the sulfur-containing polymer to be added was changed from the sulfur-containing polymer 1 to the sulfur-containing polymer 2 and the addition amount of the externally added charge control agent (b) was changed to 0.2 parts. As a result, very good results were obtained.

< Reference Example 1 >
Evaluation was made in the same manner as in Example 1 except that the kind of sulfur-containing polymer to be added was changed from sulfur-containing polymer 1 to sulfur-containing polymer 3 and the charge control agent (b) added externally was changed to 0.7 part. As a result, although it was at a level where there was no problem in practical use, the fog that was presumed to be due to an excessive amount of the externally added charge control agent was slightly deteriorated.

<Example 4>
The kind of sulfur-containing polymer to be added is changed from sulfur-containing polymer 1 to sulfur-containing polymer 2, the number of added parts is changed to 0.6 parts by mass, and the charge control agent (b) is changed to TN-105 (retained zirconium complex). The evaluation was the same as in Example 1 except that the number of internal additions was changed to 1 part and the number of external additions was changed to 0.1 parts. Obtained.

<Example 5>
When the addition amount of the sulfur-containing polymer to be added and the addition amounts of the charge control agents (a) and (b) to be added internally and externally were changed as shown in Table 2, they were evaluated in the same manner as in Example 4 and were generally good Results were obtained.

< Reference Example 2 >
The charge control agent to be added internally was changed to salicylic acid zinc complex E-84 (manufactured by Orient Chemical Co., Ltd.), and the externally added charge control agent was salicylic acid zirconium complex TN-105 (Hodogaya Chemical Co., Ltd.). The same procedure as in Example 2 was conducted except that the addition amount was changed as shown in Table 2.

<Example 7>
In Reference Example 2 , the externally added charge control agent was changed to a salicylic acid zinc complex E-84 (manufactured by Orient Chemical Co., Ltd.), and the number of added parts was changed as shown in Table 2.

<Example 8>
The type and addition amount of the sulfur-containing resin were changed as shown in Table 2, the charge control agent to be added internally and externally was changed to benzylic acid boron complex LR-147 (manufactured by Nippon Carlit Co., Ltd.), and the addition amount was changed to Table 2. The procedure was the same as in Example 1 except that the change was made as shown in FIG.

< Reference Example 3 >
The type and addition amount of the sulfur-containing resin were changed as shown in Table 2, the charge control agent to be added internally and externally was changed to benzylic acid aluminum complex LR-297 (manufactured by Nippon Carlit Co., Ltd.), and the addition amount was changed to Table 2. The procedure was the same as in Example 1 except that the change was made as shown in FIG.

<Example 10>
In Example 2, the type of colorant to be added is C.I. I. Except for changing to Pigment Yellow 93, the same procedure as in Example 2 was performed.

<Example 11>
In Example 2, the type and amount of the colorant to be added were changed to C.I. I. The same procedure as in Example 2 was performed except that the pigment red 122 was changed to 8 parts by mass.

<Example 12>
In Example 2, the kind and amount of the colorant to be added, except for changing the carbon black (DBP oil absorption of 42cm ^3/100 g, a specific surface area of 60 m ² / g) to 8 parts were the same as in Example 2.

<Comparative Examples 1-6>
In Example 1, it carried out similarly to Example 1 except having changed the kind and quantity of the sulfur-containing resin and charge control agent to add to Table 2. In addition, E-89 (made by Orient Chemical Industry Co., Ltd.) in the table is Chemical Lix Allen.

<Example 13>
Next, using a machine in which the process speed of the full-color color printer LBP2510 (manufactured by Canon) was modified to 180 mm / sec (modified to a peripheral speed of the toner carrier 270 mm / sec), [cyan toner produced in Toner Production Example 2] ], [Yellow toner produced in toner production example 10], [Magenta toner produced in toner production example 11], and [Black toner produced in toner production example 12] are filled in 200 g respectively. , 20000 full-color images were evaluated. The results were evaluated according to Example 1. The results are shown in Table 3.

It is a schematic block diagram of an example of the apparatus which implements the image forming method of this invention. An example of the surface potential profile on the toner carrier of the present invention is shown. It is a schematic block diagram of the other example of the apparatus which enforces the image forming method of this invention. It is a schematic block diagram of the other example of the apparatus which enforces the image forming method of this invention. It is a schematic block diagram of the other example of the apparatus which enforces the image forming method of this invention. It is a schematic block diagram of the other example of the apparatus which enforces the image forming method of this invention. It is a schematic block diagram of the remodeling machine used in the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging roller 4Y Each color developing device 4M Each color developing device 4Bk Each color developing device 4C Each color developing device 5 Intermediate transfer drum 5a Conductive support 5b Elastic layer 6 Cleaner with cleaning blade 7 Transfer material tray 8 Transfer device 9 Fixing device 9a Heating roller for fixing 9b Pressure roller for fixing 10 Rotary units 16a to 16d Charging means 17a to 17d Developing means 18a to 18d Cleaning means 19a to 19d Photosensitive drum 20 Charger 22 Fixing means 23a Latent image forming means 23b to 23d Latent image Forming means 24a to 24d Transfer discharging means 25 Conveying belt 26 Discharge port 27 Adsorption charging means 28a to 28d Separating / discharging discharge means 29a to 29d Image forming unit 40 Intermediate transfer belt 41 Roller 42 Primary transfer roller 43a Secondary transfer counter roller -43b Secondary transfer roller 44 Primary transfer bias power supply 45 Bias power supply 46 Secondary transfer bias power supply 49 Belt cleaner 100 Developing device 101 Developing blade 102 Toner carrier 103 Application roller 104 Toner 105 Transfer object 106 Transfer member 107 Fixing pressure Roller 108 Heating roller for fixing 109 Photoconductor 110 Primary charging member (charging roller)
110a Conductive elastic layer 110b Core metal 115 Charging bias power supply 116 Transfer bias power supply 117 Development bias power supply 123 Exposure 138 Cleaner having a cleaning blade 241 Photoconductor 241a Photoconductive insulating material layer 241b Photosensitive layer 242 Charging roller 242a Conductive elastic layer 242b Core Gold 243 Exposure 244 Development unit 244-1 to 244-4 Developer 245 Intermediate transfer drum 245a Medium resistance elastic layer 245b Pipe-shaped conductive core 246 Transfer material 247 Transfer means 247a Bias roller 247a1 Conductive elastic layer
247a2 Core metal 247c Tension roller 247d Secondary transfer bias power supply 248 Cleaning blade 249 Cleaning means 280 Detachable cleaning means 281 Fixing means P, S Recording material L Light source device E Laser light

Claims (6)

In a nonmagnetic toner comprising a toner particle having a binder resin, a colorant, a charge control agent (a) and a polymer having a sulfur atom, and a charge control agent (b) externally added to the toner particle ,
The toner particles are obtained by a polymerization method using an aqueous phase,
The charge control agents (a) and (b) are metal compounds having a metal M selected from any of Al, Zn, Zr, Fe, and B of oxycarboxylic acids,
The polymer having a sulfur atom is a vinyl polymer containing the following general formula (1) of Mw = 20,000 to 50,000 as a structural unit,
The when the non-magnetic toner and alkali washing, determined by X-ray fluorescence loss of the charge control agent (b) derived from the metal (M), parts by weight of the charge control agent present on the toner surface (b) is, the 0.020 to 0.700 part with respect to 100 parts by mass of toner particles,
The total mass A (mg / g) of oxycarboxylic acid extracted from 1 g of the nonmagnetic toner with a 0.1 mol / L sodium hydroxide aqueous solution is 0.5 to 5.0 mg / g (toner mass basis). ,
When the developing machine is filled with the non-magnetic toner and the toner carrier is rotated at a peripheral speed of 135 mm / sec in an environment of 30 ° C. and 80%, the surface potential (i) of the non-magnetic toner after 10 seconds elapses. The surface potential (ii) of the non-magnetic toner after lapse of 60 seconds is -5 to -50 V, and (i / ii) is 0.5 to 1.3.
A nonmagnetic toner, wherein the nonmagnetic toner has an average circularity of 0.955 to 0.995 and a circularity standard deviation of less than 0.045.

[Wherein R ₁ represents a hydrogen atom or a methyl group, and R ₂ and R ₃ represent a hydrogen atom or an alkyl group. Further, n represents represent an integer of 1 to 10, X ₁ represents a hydrogen atom. ]   Mw of the polymer having sulfur atoms is Mw = 27000 to 45000, and the central metal M of the charge control agent (b) is a metal selected from any one of Al, Zn, and Zr, The nonmagnetic toner according to claim 1, wherein the average circularity is 0.970 to 0.995 and the circularity standard deviation is less than 0.035. The ratio (S / C) of atomic number% (S) of sulfur element to atomic number% (C) of carbon element present on the toner surface measured by X-ray photoelectron spectroscopy is 0.0005 to 0.0050. ,
The mass part of the charge control agent (a) present inside the toner, determined by the fluorescent X-ray dose of the metal (M2) derived from the charge control agent (a) detected after the toner is washed with an alkali, is 0.00. non-magnetic toner according to claim 1 or 2, characterized in that it is from 02 to 0.5 parts (based on the weight of toner). The (S / C) relationship is 0.001 to 0.004 and exists in the toner, which is determined by the fluorescent X-ray dose of the metal (M2) derived from the charge control agent (a) detected after the alkali cleaning. The nonmagnetic toner according to claim 3 , wherein a mass part of the charge control agent (a) is 0.06 to 0.4 part (toner mass standard). Wherein (i) is -7 to-40V, the (ii) a is -7 to-45V, and claim 1, wherein (i / ii) is characterized by a 0.7-1 5. The nonmagnetic toner according to any one of 4 to 4 . In an image forming method having a developing step of visualizing the electrostatic latent image by transferring toner to the electrostatic latent image carried on the image carrier by developing means,
The developing means includes a rotatable toner carrier that carries toner and is disposed opposite to the image carrier, and a toner regulating member that regulates the amount of toner on the toner carrier,
The toner image forming method which is a non-magnetic toner according to any one of claims 1 to 5.

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